Quotient of sum of exps

Percentage Accurate: 98.9% → 98.9%
Time: 7.7s
Alternatives: 20
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ \frac{e^{a}}{e^{a} + e^{b}} \end{array} \]
(FPCore (a b) :precision binary64 (/ (exp a) (+ (exp a) (exp b))))
double code(double a, double b) {
	return exp(a) / (exp(a) + exp(b));
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = exp(a) / (exp(a) + exp(b))
end function
public static double code(double a, double b) {
	return Math.exp(a) / (Math.exp(a) + Math.exp(b));
}
def code(a, b):
	return math.exp(a) / (math.exp(a) + math.exp(b))
function code(a, b)
	return Float64(exp(a) / Float64(exp(a) + exp(b)))
end
function tmp = code(a, b)
	tmp = exp(a) / (exp(a) + exp(b));
end
code[a_, b_] := N[(N[Exp[a], $MachinePrecision] / N[(N[Exp[a], $MachinePrecision] + N[Exp[b], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{e^{a}}{e^{a} + e^{b}}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 20 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 98.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{e^{a}}{e^{a} + e^{b}} \end{array} \]
(FPCore (a b) :precision binary64 (/ (exp a) (+ (exp a) (exp b))))
double code(double a, double b) {
	return exp(a) / (exp(a) + exp(b));
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = exp(a) / (exp(a) + exp(b))
end function
public static double code(double a, double b) {
	return Math.exp(a) / (Math.exp(a) + Math.exp(b));
}
def code(a, b):
	return math.exp(a) / (math.exp(a) + math.exp(b))
function code(a, b)
	return Float64(exp(a) / Float64(exp(a) + exp(b)))
end
function tmp = code(a, b)
	tmp = exp(a) / (exp(a) + exp(b));
end
code[a_, b_] := N[(N[Exp[a], $MachinePrecision] / N[(N[Exp[a], $MachinePrecision] + N[Exp[b], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{e^{a}}{e^{a} + e^{b}}
\end{array}

Alternative 1: 98.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{e^{a}}{e^{a} + e^{b}} \end{array} \]
(FPCore (a b) :precision binary64 (/ (exp a) (+ (exp a) (exp b))))
double code(double a, double b) {
	return exp(a) / (exp(a) + exp(b));
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = exp(a) / (exp(a) + exp(b))
end function
public static double code(double a, double b) {
	return Math.exp(a) / (Math.exp(a) + Math.exp(b));
}
def code(a, b):
	return math.exp(a) / (math.exp(a) + math.exp(b))
function code(a, b)
	return Float64(exp(a) / Float64(exp(a) + exp(b)))
end
function tmp = code(a, b)
	tmp = exp(a) / (exp(a) + exp(b));
end
code[a_, b_] := N[(N[Exp[a], $MachinePrecision] / N[(N[Exp[a], $MachinePrecision] + N[Exp[b], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{e^{a}}{e^{a} + e^{b}}
\end{array}
Derivation
  1. Initial program 98.8%

    \[\frac{e^{a}}{e^{a} + e^{b}} \]
  2. Add Preprocessing
  3. Add Preprocessing

Alternative 2: 98.4% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{a} \leq 0.001:\\ \;\;\;\;\frac{1}{1 + e^{-a}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{e^{b} + 1}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= (exp a) 0.001) (/ 1.0 (+ 1.0 (exp (- a)))) (/ 1.0 (+ (exp b) 1.0))))
double code(double a, double b) {
	double tmp;
	if (exp(a) <= 0.001) {
		tmp = 1.0 / (1.0 + exp(-a));
	} else {
		tmp = 1.0 / (exp(b) + 1.0);
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (exp(a) <= 0.001d0) then
        tmp = 1.0d0 / (1.0d0 + exp(-a))
    else
        tmp = 1.0d0 / (exp(b) + 1.0d0)
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (Math.exp(a) <= 0.001) {
		tmp = 1.0 / (1.0 + Math.exp(-a));
	} else {
		tmp = 1.0 / (Math.exp(b) + 1.0);
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if math.exp(a) <= 0.001:
		tmp = 1.0 / (1.0 + math.exp(-a))
	else:
		tmp = 1.0 / (math.exp(b) + 1.0)
	return tmp
function code(a, b)
	tmp = 0.0
	if (exp(a) <= 0.001)
		tmp = Float64(1.0 / Float64(1.0 + exp(Float64(-a))));
	else
		tmp = Float64(1.0 / Float64(exp(b) + 1.0));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (exp(a) <= 0.001)
		tmp = 1.0 / (1.0 + exp(-a));
	else
		tmp = 1.0 / (exp(b) + 1.0);
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[N[Exp[a], $MachinePrecision], 0.001], N[(1.0 / N[(1.0 + N[Exp[(-a)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[Exp[b], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;e^{a} \leq 0.001:\\
\;\;\;\;\frac{1}{1 + e^{-a}}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{e^{b} + 1}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (exp.f64 a) < 1e-3

    1. Initial program 98.7%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
      2. clear-numN/A

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. inv-powN/A

        \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
      4. sqr-powN/A

        \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
      5. pow2N/A

        \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
      6. lower-pow.f64N/A

        \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
      7. lower-pow.f64N/A

        \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
      8. div-invN/A

        \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
      9. lower-*.f64N/A

        \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
      10. lift-exp.f64N/A

        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
      11. rec-expN/A

        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
      12. lower-exp.f64N/A

        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
      13. lower-neg.f64N/A

        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
      14. metadata-eval98.7

        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
    4. Applied rewrites98.7%

      \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
    5. Taylor expanded in b around 0

      \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
    6. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
      2. +-commutativeN/A

        \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
      3. distribute-lft-inN/A

        \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
      4. exp-negN/A

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
      5. lft-mult-inverseN/A

        \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
      6. *-rgt-identityN/A

        \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
      7. lower-+.f64N/A

        \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
      8. lower-exp.f64N/A

        \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
      9. lower-neg.f6498.7

        \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
    7. Applied rewrites98.7%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]

    if 1e-3 < (exp.f64 a)

    1. Initial program 98.9%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Add Preprocessing
    3. Taylor expanded in a around 0

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
    4. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
      2. lower-+.f64N/A

        \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
      3. lower-exp.f6498.0

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
    5. Applied rewrites98.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;e^{a} \leq 0.001:\\ \;\;\;\;\frac{1}{1 + e^{-a}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{e^{b} + 1}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 98.4% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{a} \leq 0:\\ \;\;\;\;\frac{e^{a}}{1 + 1}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{e^{b} + 1}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= (exp a) 0.0) (/ (exp a) (+ 1.0 1.0)) (/ 1.0 (+ (exp b) 1.0))))
double code(double a, double b) {
	double tmp;
	if (exp(a) <= 0.0) {
		tmp = exp(a) / (1.0 + 1.0);
	} else {
		tmp = 1.0 / (exp(b) + 1.0);
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (exp(a) <= 0.0d0) then
        tmp = exp(a) / (1.0d0 + 1.0d0)
    else
        tmp = 1.0d0 / (exp(b) + 1.0d0)
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (Math.exp(a) <= 0.0) {
		tmp = Math.exp(a) / (1.0 + 1.0);
	} else {
		tmp = 1.0 / (Math.exp(b) + 1.0);
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if math.exp(a) <= 0.0:
		tmp = math.exp(a) / (1.0 + 1.0)
	else:
		tmp = 1.0 / (math.exp(b) + 1.0)
	return tmp
function code(a, b)
	tmp = 0.0
	if (exp(a) <= 0.0)
		tmp = Float64(exp(a) / Float64(1.0 + 1.0));
	else
		tmp = Float64(1.0 / Float64(exp(b) + 1.0));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (exp(a) <= 0.0)
		tmp = exp(a) / (1.0 + 1.0);
	else
		tmp = 1.0 / (exp(b) + 1.0);
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[N[Exp[a], $MachinePrecision], 0.0], N[(N[Exp[a], $MachinePrecision] / N[(1.0 + 1.0), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[Exp[b], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;e^{a} \leq 0:\\
\;\;\;\;\frac{e^{a}}{1 + 1}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{e^{b} + 1}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (exp.f64 a) < 0.0

    1. Initial program 98.7%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Add Preprocessing
    3. Taylor expanded in b around 0

      \[\leadsto \frac{e^{a}}{e^{a} + \color{blue}{1}} \]
    4. Step-by-step derivation
      1. Applied rewrites100.0%

        \[\leadsto \frac{e^{a}}{e^{a} + \color{blue}{1}} \]
      2. Taylor expanded in a around 0

        \[\leadsto \frac{e^{a}}{\color{blue}{1} + 1} \]
      3. Step-by-step derivation
        1. Applied rewrites100.0%

          \[\leadsto \frac{e^{a}}{\color{blue}{1} + 1} \]

        if 0.0 < (exp.f64 a)

        1. Initial program 98.9%

          \[\frac{e^{a}}{e^{a} + e^{b}} \]
        2. Add Preprocessing
        3. Taylor expanded in a around 0

          \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
        4. Step-by-step derivation
          1. lower-/.f64N/A

            \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
          2. lower-+.f64N/A

            \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
          3. lower-exp.f6497.1

            \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
        5. Applied rewrites97.1%

          \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
      4. Recombined 2 regimes into one program.
      5. Final simplification97.9%

        \[\leadsto \begin{array}{l} \mathbf{if}\;e^{a} \leq 0:\\ \;\;\;\;\frac{e^{a}}{1 + 1}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{e^{b} + 1}\\ \end{array} \]
      6. Add Preprocessing

      Alternative 4: 93.2% accurate, 2.5× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -2 \cdot 10^{+154}:\\ \;\;\;\;\frac{1}{0.5 \cdot \left(a \cdot a\right)}\\ \mathbf{elif}\;a \leq -4.2 \cdot 10^{+36}:\\ \;\;\;\;\frac{1}{\frac{\mathsf{fma}\left(a, \mathsf{fma}\left(a, 0.5, -1\right) \cdot \left(a \cdot \mathsf{fma}\left(a, 0.5, -1\right)\right), -4\right)}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, 0.5, -1\right), -2\right)}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{e^{b} + 1}\\ \end{array} \end{array} \]
      (FPCore (a b)
       :precision binary64
       (if (<= a -2e+154)
         (/ 1.0 (* 0.5 (* a a)))
         (if (<= a -4.2e+36)
           (/
            1.0
            (/
             (fma a (* (fma a 0.5 -1.0) (* a (fma a 0.5 -1.0))) -4.0)
             (fma a (fma a 0.5 -1.0) -2.0)))
           (/ 1.0 (+ (exp b) 1.0)))))
      double code(double a, double b) {
      	double tmp;
      	if (a <= -2e+154) {
      		tmp = 1.0 / (0.5 * (a * a));
      	} else if (a <= -4.2e+36) {
      		tmp = 1.0 / (fma(a, (fma(a, 0.5, -1.0) * (a * fma(a, 0.5, -1.0))), -4.0) / fma(a, fma(a, 0.5, -1.0), -2.0));
      	} else {
      		tmp = 1.0 / (exp(b) + 1.0);
      	}
      	return tmp;
      }
      
      function code(a, b)
      	tmp = 0.0
      	if (a <= -2e+154)
      		tmp = Float64(1.0 / Float64(0.5 * Float64(a * a)));
      	elseif (a <= -4.2e+36)
      		tmp = Float64(1.0 / Float64(fma(a, Float64(fma(a, 0.5, -1.0) * Float64(a * fma(a, 0.5, -1.0))), -4.0) / fma(a, fma(a, 0.5, -1.0), -2.0)));
      	else
      		tmp = Float64(1.0 / Float64(exp(b) + 1.0));
      	end
      	return tmp
      end
      
      code[a_, b_] := If[LessEqual[a, -2e+154], N[(1.0 / N[(0.5 * N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[a, -4.2e+36], N[(1.0 / N[(N[(a * N[(N[(a * 0.5 + -1.0), $MachinePrecision] * N[(a * N[(a * 0.5 + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -4.0), $MachinePrecision] / N[(a * N[(a * 0.5 + -1.0), $MachinePrecision] + -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[Exp[b], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;a \leq -2 \cdot 10^{+154}:\\
      \;\;\;\;\frac{1}{0.5 \cdot \left(a \cdot a\right)}\\
      
      \mathbf{elif}\;a \leq -4.2 \cdot 10^{+36}:\\
      \;\;\;\;\frac{1}{\frac{\mathsf{fma}\left(a, \mathsf{fma}\left(a, 0.5, -1\right) \cdot \left(a \cdot \mathsf{fma}\left(a, 0.5, -1\right)\right), -4\right)}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, 0.5, -1\right), -2\right)}}\\
      
      \mathbf{else}:\\
      \;\;\;\;\frac{1}{e^{b} + 1}\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 3 regimes
      2. if a < -2.00000000000000007e154

        1. Initial program 100.0%

          \[\frac{e^{a}}{e^{a} + e^{b}} \]
        2. Add Preprocessing
        3. Step-by-step derivation
          1. lift-/.f64N/A

            \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
          2. clear-numN/A

            \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
          3. inv-powN/A

            \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
          4. sqr-powN/A

            \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
          5. pow2N/A

            \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
          6. lower-pow.f64N/A

            \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
          7. lower-pow.f64N/A

            \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
          8. div-invN/A

            \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
          9. lower-*.f64N/A

            \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
          10. lift-exp.f64N/A

            \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
          11. rec-expN/A

            \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
          12. lower-exp.f64N/A

            \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
          13. lower-neg.f64N/A

            \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
          14. metadata-eval100.0

            \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
        4. Applied rewrites100.0%

          \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
        5. Taylor expanded in b around 0

          \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
        6. Step-by-step derivation
          1. lower-/.f64N/A

            \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
          2. +-commutativeN/A

            \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
          3. distribute-lft-inN/A

            \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
          4. exp-negN/A

            \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
          5. lft-mult-inverseN/A

            \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
          6. *-rgt-identityN/A

            \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
          7. lower-+.f64N/A

            \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
          8. lower-exp.f64N/A

            \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
          9. lower-neg.f64100.0

            \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
        7. Applied rewrites100.0%

          \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
        8. Taylor expanded in a around 0

          \[\leadsto \frac{1}{2 + \color{blue}{a \cdot \left(\frac{1}{2} \cdot a - 1\right)}} \]
        9. Step-by-step derivation
          1. Applied rewrites100.0%

            \[\leadsto \frac{1}{\mathsf{fma}\left(a, \color{blue}{\mathsf{fma}\left(a, 0.5, -1\right)}, 2\right)} \]
          2. Taylor expanded in a around inf

            \[\leadsto \frac{1}{\frac{1}{2} \cdot {a}^{\color{blue}{2}}} \]
          3. Step-by-step derivation
            1. Applied rewrites100.0%

              \[\leadsto \frac{1}{0.5 \cdot \left(a \cdot \color{blue}{a}\right)} \]

            if -2.00000000000000007e154 < a < -4.20000000000000009e36

            1. Initial program 96.0%

              \[\frac{e^{a}}{e^{a} + e^{b}} \]
            2. Add Preprocessing
            3. Step-by-step derivation
              1. lift-/.f64N/A

                \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
              2. clear-numN/A

                \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
              3. inv-powN/A

                \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
              4. sqr-powN/A

                \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
              5. pow2N/A

                \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
              6. lower-pow.f64N/A

                \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
              7. lower-pow.f64N/A

                \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
              8. div-invN/A

                \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
              9. lower-*.f64N/A

                \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
              10. lift-exp.f64N/A

                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
              11. rec-expN/A

                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
              12. lower-exp.f64N/A

                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
              13. lower-neg.f64N/A

                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
              14. metadata-eval96.0

                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
            4. Applied rewrites96.0%

              \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
            5. Taylor expanded in b around 0

              \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
            6. Step-by-step derivation
              1. lower-/.f64N/A

                \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
              2. +-commutativeN/A

                \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
              3. distribute-lft-inN/A

                \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
              4. exp-negN/A

                \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
              5. lft-mult-inverseN/A

                \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
              6. *-rgt-identityN/A

                \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
              7. lower-+.f64N/A

                \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
              8. lower-exp.f64N/A

                \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
              9. lower-neg.f64100.0

                \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
            7. Applied rewrites100.0%

              \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
            8. Taylor expanded in a around 0

              \[\leadsto \frac{1}{2 + \color{blue}{a \cdot \left(\frac{1}{2} \cdot a - 1\right)}} \]
            9. Step-by-step derivation
              1. Applied rewrites5.9%

                \[\leadsto \frac{1}{\mathsf{fma}\left(a, \color{blue}{\mathsf{fma}\left(a, 0.5, -1\right)}, 2\right)} \]
              2. Step-by-step derivation
                1. Applied rewrites77.0%

                  \[\leadsto \frac{1}{\frac{\mathsf{fma}\left(a, \mathsf{fma}\left(a, 0.5, -1\right) \cdot \left(a \cdot \mathsf{fma}\left(a, 0.5, -1\right)\right), -4\right)}{\mathsf{fma}\left(a, \color{blue}{\mathsf{fma}\left(a, 0.5, -1\right)}, -2\right)}} \]

                if -4.20000000000000009e36 < a

                1. Initial program 98.9%

                  \[\frac{e^{a}}{e^{a} + e^{b}} \]
                2. Add Preprocessing
                3. Taylor expanded in a around 0

                  \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                4. Step-by-step derivation
                  1. lower-/.f64N/A

                    \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                  2. lower-+.f64N/A

                    \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                  3. lower-exp.f6494.2

                    \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                5. Applied rewrites94.2%

                  \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
              3. Recombined 3 regimes into one program.
              4. Final simplification93.4%

                \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -2 \cdot 10^{+154}:\\ \;\;\;\;\frac{1}{0.5 \cdot \left(a \cdot a\right)}\\ \mathbf{elif}\;a \leq -4.2 \cdot 10^{+36}:\\ \;\;\;\;\frac{1}{\frac{\mathsf{fma}\left(a, \mathsf{fma}\left(a, 0.5, -1\right) \cdot \left(a \cdot \mathsf{fma}\left(a, 0.5, -1\right)\right), -4\right)}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, 0.5, -1\right), -2\right)}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{e^{b} + 1}\\ \end{array} \]
              5. Add Preprocessing

              Alternative 5: 73.1% accurate, 3.4× speedup?

              \[\begin{array}{l} \\ \begin{array}{l} t_0 := \mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right)\\ \mathbf{if}\;b \leq 1.55 \cdot 10^{-26}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\ \mathbf{elif}\;b \leq 1.05 \cdot 10^{+103}:\\ \;\;\;\;\frac{1}{\frac{\mathsf{fma}\left(b \cdot b, t\_0 \cdot t\_0, -4\right)}{\mathsf{fma}\left(b, t\_0, -2\right)}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b \cdot \left(\left(b \cdot b\right) \cdot 0.16666666666666666\right)}\\ \end{array} \end{array} \]
              (FPCore (a b)
               :precision binary64
               (let* ((t_0 (fma b (fma b 0.16666666666666666 0.5) 1.0)))
                 (if (<= b 1.55e-26)
                   (/ 1.0 (fma a (fma a (fma a -0.16666666666666666 0.5) -1.0) 2.0))
                   (if (<= b 1.05e+103)
                     (/ 1.0 (/ (fma (* b b) (* t_0 t_0) -4.0) (fma b t_0 -2.0)))
                     (/ 1.0 (* b (* (* b b) 0.16666666666666666)))))))
              double code(double a, double b) {
              	double t_0 = fma(b, fma(b, 0.16666666666666666, 0.5), 1.0);
              	double tmp;
              	if (b <= 1.55e-26) {
              		tmp = 1.0 / fma(a, fma(a, fma(a, -0.16666666666666666, 0.5), -1.0), 2.0);
              	} else if (b <= 1.05e+103) {
              		tmp = 1.0 / (fma((b * b), (t_0 * t_0), -4.0) / fma(b, t_0, -2.0));
              	} else {
              		tmp = 1.0 / (b * ((b * b) * 0.16666666666666666));
              	}
              	return tmp;
              }
              
              function code(a, b)
              	t_0 = fma(b, fma(b, 0.16666666666666666, 0.5), 1.0)
              	tmp = 0.0
              	if (b <= 1.55e-26)
              		tmp = Float64(1.0 / fma(a, fma(a, fma(a, -0.16666666666666666, 0.5), -1.0), 2.0));
              	elseif (b <= 1.05e+103)
              		tmp = Float64(1.0 / Float64(fma(Float64(b * b), Float64(t_0 * t_0), -4.0) / fma(b, t_0, -2.0)));
              	else
              		tmp = Float64(1.0 / Float64(b * Float64(Float64(b * b) * 0.16666666666666666)));
              	end
              	return tmp
              end
              
              code[a_, b_] := Block[{t$95$0 = N[(b * N[(b * 0.16666666666666666 + 0.5), $MachinePrecision] + 1.0), $MachinePrecision]}, If[LessEqual[b, 1.55e-26], N[(1.0 / N[(a * N[(a * N[(a * -0.16666666666666666 + 0.5), $MachinePrecision] + -1.0), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 1.05e+103], N[(1.0 / N[(N[(N[(b * b), $MachinePrecision] * N[(t$95$0 * t$95$0), $MachinePrecision] + -4.0), $MachinePrecision] / N[(b * t$95$0 + -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(b * N[(N[(b * b), $MachinePrecision] * 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
              
              \begin{array}{l}
              
              \\
              \begin{array}{l}
              t_0 := \mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right)\\
              \mathbf{if}\;b \leq 1.55 \cdot 10^{-26}:\\
              \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\
              
              \mathbf{elif}\;b \leq 1.05 \cdot 10^{+103}:\\
              \;\;\;\;\frac{1}{\frac{\mathsf{fma}\left(b \cdot b, t\_0 \cdot t\_0, -4\right)}{\mathsf{fma}\left(b, t\_0, -2\right)}}\\
              
              \mathbf{else}:\\
              \;\;\;\;\frac{1}{b \cdot \left(\left(b \cdot b\right) \cdot 0.16666666666666666\right)}\\
              
              
              \end{array}
              \end{array}
              
              Derivation
              1. Split input into 3 regimes
              2. if b < 1.54999999999999992e-26

                1. Initial program 98.4%

                  \[\frac{e^{a}}{e^{a} + e^{b}} \]
                2. Add Preprocessing
                3. Step-by-step derivation
                  1. lift-/.f64N/A

                    \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
                  2. clear-numN/A

                    \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                  3. inv-powN/A

                    \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
                  4. sqr-powN/A

                    \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
                  5. pow2N/A

                    \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                  6. lower-pow.f64N/A

                    \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                  7. lower-pow.f64N/A

                    \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
                  8. div-invN/A

                    \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                  9. lower-*.f64N/A

                    \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                  10. lift-exp.f64N/A

                    \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                  11. rec-expN/A

                    \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                  12. lower-exp.f64N/A

                    \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                  13. lower-neg.f64N/A

                    \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                  14. metadata-eval97.7

                    \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
                4. Applied rewrites97.7%

                  \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
                5. Taylor expanded in b around 0

                  \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                6. Step-by-step derivation
                  1. lower-/.f64N/A

                    \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                  2. +-commutativeN/A

                    \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
                  3. distribute-lft-inN/A

                    \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
                  4. exp-negN/A

                    \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                  5. lft-mult-inverseN/A

                    \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                  6. *-rgt-identityN/A

                    \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                  7. lower-+.f64N/A

                    \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                  8. lower-exp.f64N/A

                    \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                  9. lower-neg.f6480.7

                    \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                7. Applied rewrites80.7%

                  \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
                8. Taylor expanded in a around 0

                  \[\leadsto \frac{1}{2 + \color{blue}{a \cdot \left(a \cdot \left(\frac{1}{2} + \frac{-1}{6} \cdot a\right) - 1\right)}} \]
                9. Step-by-step derivation
                  1. Applied rewrites69.5%

                    \[\leadsto \frac{1}{\mathsf{fma}\left(a, \color{blue}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right)}, 2\right)} \]

                  if 1.54999999999999992e-26 < b < 1.0500000000000001e103

                  1. Initial program 99.9%

                    \[\frac{e^{a}}{e^{a} + e^{b}} \]
                  2. Add Preprocessing
                  3. Taylor expanded in a around 0

                    \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                  4. Step-by-step derivation
                    1. lower-/.f64N/A

                      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                    2. lower-+.f64N/A

                      \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                    3. lower-exp.f6496.4

                      \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                  5. Applied rewrites96.4%

                    \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                  6. Taylor expanded in b around 0

                    \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + b \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot b\right)\right)}} \]
                  7. Step-by-step derivation
                    1. Applied rewrites19.8%

                      \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right)}, 2\right)} \]
                    2. Step-by-step derivation
                      1. Applied rewrites82.4%

                        \[\leadsto \frac{1}{\frac{\mathsf{fma}\left(b \cdot b, \mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right) \cdot \mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right), -4\right)}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right)}, -2\right)}} \]

                      if 1.0500000000000001e103 < b

                      1. Initial program 100.0%

                        \[\frac{e^{a}}{e^{a} + e^{b}} \]
                      2. Add Preprocessing
                      3. Taylor expanded in a around 0

                        \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                      4. Step-by-step derivation
                        1. lower-/.f64N/A

                          \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                        2. lower-+.f64N/A

                          \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                        3. lower-exp.f64100.0

                          \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                      5. Applied rewrites100.0%

                        \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                      6. Taylor expanded in b around 0

                        \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + b \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot b\right)\right)}} \]
                      7. Step-by-step derivation
                        1. Applied rewrites100.0%

                          \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right)}, 2\right)} \]
                        2. Taylor expanded in b around inf

                          \[\leadsto \frac{1}{\frac{1}{6} \cdot {b}^{\color{blue}{3}}} \]
                        3. Step-by-step derivation
                          1. Applied rewrites100.0%

                            \[\leadsto \frac{1}{b \cdot \left(0.16666666666666666 \cdot \color{blue}{\left(b \cdot b\right)}\right)} \]
                        4. Recombined 3 regimes into one program.
                        5. Final simplification75.3%

                          \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 1.55 \cdot 10^{-26}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\ \mathbf{elif}\;b \leq 1.05 \cdot 10^{+103}:\\ \;\;\;\;\frac{1}{\frac{\mathsf{fma}\left(b \cdot b, \mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right) \cdot \mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right), -4\right)}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right), -2\right)}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b \cdot \left(\left(b \cdot b\right) \cdot 0.16666666666666666\right)}\\ \end{array} \]
                        6. Add Preprocessing

                        Alternative 6: 73.4% accurate, 3.7× speedup?

                        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 6.1 \cdot 10^{+57}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\ \mathbf{elif}\;b \leq 10^{+154}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(b \cdot \mathsf{fma}\left(\mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), \left(b \cdot b\right) \cdot \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), -1\right), \frac{1}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), -1\right)}, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b \cdot \left(b \cdot 0.5\right)}\\ \end{array} \end{array} \]
                        (FPCore (a b)
                         :precision binary64
                         (if (<= b 6.1e+57)
                           (/ 1.0 (fma a (fma a (fma a -0.16666666666666666 0.5) -1.0) 2.0))
                           (if (<= b 1e+154)
                             (/
                              1.0
                              (fma
                               (*
                                b
                                (fma
                                 (fma b 0.16666666666666666 0.5)
                                 (* (* b b) (fma b 0.16666666666666666 0.5))
                                 -1.0))
                               (/ 1.0 (fma b (fma b 0.16666666666666666 0.5) -1.0))
                               2.0))
                             (/ 1.0 (* b (* b 0.5))))))
                        double code(double a, double b) {
                        	double tmp;
                        	if (b <= 6.1e+57) {
                        		tmp = 1.0 / fma(a, fma(a, fma(a, -0.16666666666666666, 0.5), -1.0), 2.0);
                        	} else if (b <= 1e+154) {
                        		tmp = 1.0 / fma((b * fma(fma(b, 0.16666666666666666, 0.5), ((b * b) * fma(b, 0.16666666666666666, 0.5)), -1.0)), (1.0 / fma(b, fma(b, 0.16666666666666666, 0.5), -1.0)), 2.0);
                        	} else {
                        		tmp = 1.0 / (b * (b * 0.5));
                        	}
                        	return tmp;
                        }
                        
                        function code(a, b)
                        	tmp = 0.0
                        	if (b <= 6.1e+57)
                        		tmp = Float64(1.0 / fma(a, fma(a, fma(a, -0.16666666666666666, 0.5), -1.0), 2.0));
                        	elseif (b <= 1e+154)
                        		tmp = Float64(1.0 / fma(Float64(b * fma(fma(b, 0.16666666666666666, 0.5), Float64(Float64(b * b) * fma(b, 0.16666666666666666, 0.5)), -1.0)), Float64(1.0 / fma(b, fma(b, 0.16666666666666666, 0.5), -1.0)), 2.0));
                        	else
                        		tmp = Float64(1.0 / Float64(b * Float64(b * 0.5)));
                        	end
                        	return tmp
                        end
                        
                        code[a_, b_] := If[LessEqual[b, 6.1e+57], N[(1.0 / N[(a * N[(a * N[(a * -0.16666666666666666 + 0.5), $MachinePrecision] + -1.0), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 1e+154], N[(1.0 / N[(N[(b * N[(N[(b * 0.16666666666666666 + 0.5), $MachinePrecision] * N[(N[(b * b), $MachinePrecision] * N[(b * 0.16666666666666666 + 0.5), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision] * N[(1.0 / N[(b * N[(b * 0.16666666666666666 + 0.5), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(b * N[(b * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
                        
                        \begin{array}{l}
                        
                        \\
                        \begin{array}{l}
                        \mathbf{if}\;b \leq 6.1 \cdot 10^{+57}:\\
                        \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\
                        
                        \mathbf{elif}\;b \leq 10^{+154}:\\
                        \;\;\;\;\frac{1}{\mathsf{fma}\left(b \cdot \mathsf{fma}\left(\mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), \left(b \cdot b\right) \cdot \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), -1\right), \frac{1}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), -1\right)}, 2\right)}\\
                        
                        \mathbf{else}:\\
                        \;\;\;\;\frac{1}{b \cdot \left(b \cdot 0.5\right)}\\
                        
                        
                        \end{array}
                        \end{array}
                        
                        Derivation
                        1. Split input into 3 regimes
                        2. if b < 6.09999999999999975e57

                          1. Initial program 98.5%

                            \[\frac{e^{a}}{e^{a} + e^{b}} \]
                          2. Add Preprocessing
                          3. Step-by-step derivation
                            1. lift-/.f64N/A

                              \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
                            2. clear-numN/A

                              \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                            3. inv-powN/A

                              \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
                            4. sqr-powN/A

                              \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
                            5. pow2N/A

                              \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                            6. lower-pow.f64N/A

                              \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                            7. lower-pow.f64N/A

                              \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
                            8. div-invN/A

                              \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                            9. lower-*.f64N/A

                              \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                            10. lift-exp.f64N/A

                              \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                            11. rec-expN/A

                              \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                            12. lower-exp.f64N/A

                              \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                            13. lower-neg.f64N/A

                              \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                            14. metadata-eval97.8

                              \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
                          4. Applied rewrites97.8%

                            \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
                          5. Taylor expanded in b around 0

                            \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                          6. Step-by-step derivation
                            1. lower-/.f64N/A

                              \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                            2. +-commutativeN/A

                              \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
                            3. distribute-lft-inN/A

                              \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
                            4. exp-negN/A

                              \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                            5. lft-mult-inverseN/A

                              \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                            6. *-rgt-identityN/A

                              \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                            7. lower-+.f64N/A

                              \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                            8. lower-exp.f64N/A

                              \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                            9. lower-neg.f6478.6

                              \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                          7. Applied rewrites78.6%

                            \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
                          8. Taylor expanded in a around 0

                            \[\leadsto \frac{1}{2 + \color{blue}{a \cdot \left(a \cdot \left(\frac{1}{2} + \frac{-1}{6} \cdot a\right) - 1\right)}} \]
                          9. Step-by-step derivation
                            1. Applied rewrites67.7%

                              \[\leadsto \frac{1}{\mathsf{fma}\left(a, \color{blue}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right)}, 2\right)} \]

                            if 6.09999999999999975e57 < b < 1.00000000000000004e154

                            1. Initial program 100.0%

                              \[\frac{e^{a}}{e^{a} + e^{b}} \]
                            2. Add Preprocessing
                            3. Taylor expanded in a around 0

                              \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                            4. Step-by-step derivation
                              1. lower-/.f64N/A

                                \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                              2. lower-+.f64N/A

                                \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                              3. lower-exp.f64100.0

                                \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                            5. Applied rewrites100.0%

                              \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                            6. Taylor expanded in b around 0

                              \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + b \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot b\right)\right)}} \]
                            7. Step-by-step derivation
                              1. Applied rewrites38.9%

                                \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right)}, 2\right)} \]
                              2. Step-by-step derivation
                                1. Applied rewrites96.0%

                                  \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right) \cdot \left(b \cdot b\right), -1\right) \cdot b, \frac{1}{\color{blue}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), -1\right)}}, 2\right)} \]

                                if 1.00000000000000004e154 < b

                                1. Initial program 100.0%

                                  \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                2. Add Preprocessing
                                3. Taylor expanded in a around 0

                                  \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                4. Step-by-step derivation
                                  1. lower-/.f64N/A

                                    \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                  2. lower-+.f64N/A

                                    \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                                  3. lower-exp.f64100.0

                                    \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                5. Applied rewrites100.0%

                                  \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                6. Taylor expanded in b around 0

                                  \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                7. Step-by-step derivation
                                  1. Applied rewrites100.0%

                                    \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, 0.5, 1\right)}, 2\right)} \]
                                  2. Taylor expanded in b around inf

                                    \[\leadsto \frac{1}{\frac{1}{2} \cdot {b}^{\color{blue}{2}}} \]
                                  3. Step-by-step derivation
                                    1. Applied rewrites100.0%

                                      \[\leadsto \frac{1}{b \cdot \left(b \cdot \color{blue}{0.5}\right)} \]
                                  4. Recombined 3 regimes into one program.
                                  5. Final simplification74.0%

                                    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 6.1 \cdot 10^{+57}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\ \mathbf{elif}\;b \leq 10^{+154}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(b \cdot \mathsf{fma}\left(\mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), \left(b \cdot b\right) \cdot \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), -1\right), \frac{1}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), -1\right)}, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b \cdot \left(b \cdot 0.5\right)}\\ \end{array} \]
                                  6. Add Preprocessing

                                  Alternative 7: 72.2% accurate, 3.9× speedup?

                                  \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 6.1 \cdot 10^{+57}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\ \mathbf{elif}\;b \leq 10^{+154}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(b, \frac{\mathsf{fma}\left(\mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), \left(b \cdot b\right) \cdot \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), -1\right)}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), -1\right)}, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b \cdot \left(b \cdot 0.5\right)}\\ \end{array} \end{array} \]
                                  (FPCore (a b)
                                   :precision binary64
                                   (if (<= b 6.1e+57)
                                     (/ 1.0 (fma a (fma a (fma a -0.16666666666666666 0.5) -1.0) 2.0))
                                     (if (<= b 1e+154)
                                       (/
                                        1.0
                                        (fma
                                         b
                                         (/
                                          (fma
                                           (fma b 0.16666666666666666 0.5)
                                           (* (* b b) (fma b 0.16666666666666666 0.5))
                                           -1.0)
                                          (fma b (fma b 0.16666666666666666 0.5) -1.0))
                                         2.0))
                                       (/ 1.0 (* b (* b 0.5))))))
                                  double code(double a, double b) {
                                  	double tmp;
                                  	if (b <= 6.1e+57) {
                                  		tmp = 1.0 / fma(a, fma(a, fma(a, -0.16666666666666666, 0.5), -1.0), 2.0);
                                  	} else if (b <= 1e+154) {
                                  		tmp = 1.0 / fma(b, (fma(fma(b, 0.16666666666666666, 0.5), ((b * b) * fma(b, 0.16666666666666666, 0.5)), -1.0) / fma(b, fma(b, 0.16666666666666666, 0.5), -1.0)), 2.0);
                                  	} else {
                                  		tmp = 1.0 / (b * (b * 0.5));
                                  	}
                                  	return tmp;
                                  }
                                  
                                  function code(a, b)
                                  	tmp = 0.0
                                  	if (b <= 6.1e+57)
                                  		tmp = Float64(1.0 / fma(a, fma(a, fma(a, -0.16666666666666666, 0.5), -1.0), 2.0));
                                  	elseif (b <= 1e+154)
                                  		tmp = Float64(1.0 / fma(b, Float64(fma(fma(b, 0.16666666666666666, 0.5), Float64(Float64(b * b) * fma(b, 0.16666666666666666, 0.5)), -1.0) / fma(b, fma(b, 0.16666666666666666, 0.5), -1.0)), 2.0));
                                  	else
                                  		tmp = Float64(1.0 / Float64(b * Float64(b * 0.5)));
                                  	end
                                  	return tmp
                                  end
                                  
                                  code[a_, b_] := If[LessEqual[b, 6.1e+57], N[(1.0 / N[(a * N[(a * N[(a * -0.16666666666666666 + 0.5), $MachinePrecision] + -1.0), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 1e+154], N[(1.0 / N[(b * N[(N[(N[(b * 0.16666666666666666 + 0.5), $MachinePrecision] * N[(N[(b * b), $MachinePrecision] * N[(b * 0.16666666666666666 + 0.5), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision] / N[(b * N[(b * 0.16666666666666666 + 0.5), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(b * N[(b * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
                                  
                                  \begin{array}{l}
                                  
                                  \\
                                  \begin{array}{l}
                                  \mathbf{if}\;b \leq 6.1 \cdot 10^{+57}:\\
                                  \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\
                                  
                                  \mathbf{elif}\;b \leq 10^{+154}:\\
                                  \;\;\;\;\frac{1}{\mathsf{fma}\left(b, \frac{\mathsf{fma}\left(\mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), \left(b \cdot b\right) \cdot \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), -1\right)}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), -1\right)}, 2\right)}\\
                                  
                                  \mathbf{else}:\\
                                  \;\;\;\;\frac{1}{b \cdot \left(b \cdot 0.5\right)}\\
                                  
                                  
                                  \end{array}
                                  \end{array}
                                  
                                  Derivation
                                  1. Split input into 3 regimes
                                  2. if b < 6.09999999999999975e57

                                    1. Initial program 98.5%

                                      \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                    2. Add Preprocessing
                                    3. Step-by-step derivation
                                      1. lift-/.f64N/A

                                        \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
                                      2. clear-numN/A

                                        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                      3. inv-powN/A

                                        \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
                                      4. sqr-powN/A

                                        \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
                                      5. pow2N/A

                                        \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                      6. lower-pow.f64N/A

                                        \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                      7. lower-pow.f64N/A

                                        \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
                                      8. div-invN/A

                                        \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                      9. lower-*.f64N/A

                                        \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                      10. lift-exp.f64N/A

                                        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                      11. rec-expN/A

                                        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                      12. lower-exp.f64N/A

                                        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                      13. lower-neg.f64N/A

                                        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                      14. metadata-eval97.8

                                        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
                                    4. Applied rewrites97.8%

                                      \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
                                    5. Taylor expanded in b around 0

                                      \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                    6. Step-by-step derivation
                                      1. lower-/.f64N/A

                                        \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                      2. +-commutativeN/A

                                        \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
                                      3. distribute-lft-inN/A

                                        \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
                                      4. exp-negN/A

                                        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                      5. lft-mult-inverseN/A

                                        \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                      6. *-rgt-identityN/A

                                        \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                      7. lower-+.f64N/A

                                        \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                                      8. lower-exp.f64N/A

                                        \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                      9. lower-neg.f6478.6

                                        \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                                    7. Applied rewrites78.6%

                                      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
                                    8. Taylor expanded in a around 0

                                      \[\leadsto \frac{1}{2 + \color{blue}{a \cdot \left(a \cdot \left(\frac{1}{2} + \frac{-1}{6} \cdot a\right) - 1\right)}} \]
                                    9. Step-by-step derivation
                                      1. Applied rewrites67.7%

                                        \[\leadsto \frac{1}{\mathsf{fma}\left(a, \color{blue}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right)}, 2\right)} \]

                                      if 6.09999999999999975e57 < b < 1.00000000000000004e154

                                      1. Initial program 100.0%

                                        \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                      2. Add Preprocessing
                                      3. Taylor expanded in a around 0

                                        \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                      4. Step-by-step derivation
                                        1. lower-/.f64N/A

                                          \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                        2. lower-+.f64N/A

                                          \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                                        3. lower-exp.f64100.0

                                          \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                      5. Applied rewrites100.0%

                                        \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                      6. Taylor expanded in b around 0

                                        \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + b \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot b\right)\right)}} \]
                                      7. Step-by-step derivation
                                        1. Applied rewrites38.9%

                                          \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right)}, 2\right)} \]
                                        2. Step-by-step derivation
                                          1. Applied rewrites88.2%

                                            \[\leadsto \frac{1}{\mathsf{fma}\left(b, \frac{\mathsf{fma}\left(\mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right) \cdot \left(b \cdot b\right), -1\right)}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, 0.16666666666666666, 0.5\right)}, -1\right)}, 2\right)} \]

                                          if 1.00000000000000004e154 < b

                                          1. Initial program 100.0%

                                            \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                          2. Add Preprocessing
                                          3. Taylor expanded in a around 0

                                            \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                          4. Step-by-step derivation
                                            1. lower-/.f64N/A

                                              \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                            2. lower-+.f64N/A

                                              \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                                            3. lower-exp.f64100.0

                                              \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                          5. Applied rewrites100.0%

                                            \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                          6. Taylor expanded in b around 0

                                            \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                          7. Step-by-step derivation
                                            1. Applied rewrites100.0%

                                              \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, 0.5, 1\right)}, 2\right)} \]
                                            2. Taylor expanded in b around inf

                                              \[\leadsto \frac{1}{\frac{1}{2} \cdot {b}^{\color{blue}{2}}} \]
                                            3. Step-by-step derivation
                                              1. Applied rewrites100.0%

                                                \[\leadsto \frac{1}{b \cdot \left(b \cdot \color{blue}{0.5}\right)} \]
                                            4. Recombined 3 regimes into one program.
                                            5. Final simplification73.2%

                                              \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 6.1 \cdot 10^{+57}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\ \mathbf{elif}\;b \leq 10^{+154}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(b, \frac{\mathsf{fma}\left(\mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), \left(b \cdot b\right) \cdot \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), -1\right)}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), -1\right)}, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b \cdot \left(b \cdot 0.5\right)}\\ \end{array} \]
                                            6. Add Preprocessing

                                            Alternative 8: 72.2% accurate, 4.2× speedup?

                                            \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 6.1 \cdot 10^{+57}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\ \mathbf{elif}\;b \leq 1.9 \cdot 10^{+154}:\\ \;\;\;\;\frac{1}{\frac{\mathsf{fma}\left(\mathsf{fma}\left(b, 0.5, 1\right), b \cdot \mathsf{fma}\left(b, b \cdot 0.5, b\right), -4\right)}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.5, 1\right), -2\right)}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b \cdot \left(b \cdot 0.5\right)}\\ \end{array} \end{array} \]
                                            (FPCore (a b)
                                             :precision binary64
                                             (if (<= b 6.1e+57)
                                               (/ 1.0 (fma a (fma a (fma a -0.16666666666666666 0.5) -1.0) 2.0))
                                               (if (<= b 1.9e+154)
                                                 (/
                                                  1.0
                                                  (/
                                                   (fma (fma b 0.5 1.0) (* b (fma b (* b 0.5) b)) -4.0)
                                                   (fma b (fma b 0.5 1.0) -2.0)))
                                                 (/ 1.0 (* b (* b 0.5))))))
                                            double code(double a, double b) {
                                            	double tmp;
                                            	if (b <= 6.1e+57) {
                                            		tmp = 1.0 / fma(a, fma(a, fma(a, -0.16666666666666666, 0.5), -1.0), 2.0);
                                            	} else if (b <= 1.9e+154) {
                                            		tmp = 1.0 / (fma(fma(b, 0.5, 1.0), (b * fma(b, (b * 0.5), b)), -4.0) / fma(b, fma(b, 0.5, 1.0), -2.0));
                                            	} else {
                                            		tmp = 1.0 / (b * (b * 0.5));
                                            	}
                                            	return tmp;
                                            }
                                            
                                            function code(a, b)
                                            	tmp = 0.0
                                            	if (b <= 6.1e+57)
                                            		tmp = Float64(1.0 / fma(a, fma(a, fma(a, -0.16666666666666666, 0.5), -1.0), 2.0));
                                            	elseif (b <= 1.9e+154)
                                            		tmp = Float64(1.0 / Float64(fma(fma(b, 0.5, 1.0), Float64(b * fma(b, Float64(b * 0.5), b)), -4.0) / fma(b, fma(b, 0.5, 1.0), -2.0)));
                                            	else
                                            		tmp = Float64(1.0 / Float64(b * Float64(b * 0.5)));
                                            	end
                                            	return tmp
                                            end
                                            
                                            code[a_, b_] := If[LessEqual[b, 6.1e+57], N[(1.0 / N[(a * N[(a * N[(a * -0.16666666666666666 + 0.5), $MachinePrecision] + -1.0), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 1.9e+154], N[(1.0 / N[(N[(N[(b * 0.5 + 1.0), $MachinePrecision] * N[(b * N[(b * N[(b * 0.5), $MachinePrecision] + b), $MachinePrecision]), $MachinePrecision] + -4.0), $MachinePrecision] / N[(b * N[(b * 0.5 + 1.0), $MachinePrecision] + -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(b * N[(b * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
                                            
                                            \begin{array}{l}
                                            
                                            \\
                                            \begin{array}{l}
                                            \mathbf{if}\;b \leq 6.1 \cdot 10^{+57}:\\
                                            \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\
                                            
                                            \mathbf{elif}\;b \leq 1.9 \cdot 10^{+154}:\\
                                            \;\;\;\;\frac{1}{\frac{\mathsf{fma}\left(\mathsf{fma}\left(b, 0.5, 1\right), b \cdot \mathsf{fma}\left(b, b \cdot 0.5, b\right), -4\right)}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.5, 1\right), -2\right)}}\\
                                            
                                            \mathbf{else}:\\
                                            \;\;\;\;\frac{1}{b \cdot \left(b \cdot 0.5\right)}\\
                                            
                                            
                                            \end{array}
                                            \end{array}
                                            
                                            Derivation
                                            1. Split input into 3 regimes
                                            2. if b < 6.09999999999999975e57

                                              1. Initial program 98.5%

                                                \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                              2. Add Preprocessing
                                              3. Step-by-step derivation
                                                1. lift-/.f64N/A

                                                  \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
                                                2. clear-numN/A

                                                  \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                3. inv-powN/A

                                                  \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
                                                4. sqr-powN/A

                                                  \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
                                                5. pow2N/A

                                                  \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                6. lower-pow.f64N/A

                                                  \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                7. lower-pow.f64N/A

                                                  \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
                                                8. div-invN/A

                                                  \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                9. lower-*.f64N/A

                                                  \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                10. lift-exp.f64N/A

                                                  \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                11. rec-expN/A

                                                  \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                12. lower-exp.f64N/A

                                                  \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                13. lower-neg.f64N/A

                                                  \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                14. metadata-eval97.8

                                                  \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
                                              4. Applied rewrites97.8%

                                                \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
                                              5. Taylor expanded in b around 0

                                                \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                              6. Step-by-step derivation
                                                1. lower-/.f64N/A

                                                  \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                2. +-commutativeN/A

                                                  \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
                                                3. distribute-lft-inN/A

                                                  \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
                                                4. exp-negN/A

                                                  \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                5. lft-mult-inverseN/A

                                                  \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                6. *-rgt-identityN/A

                                                  \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                7. lower-+.f64N/A

                                                  \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                                                8. lower-exp.f64N/A

                                                  \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                9. lower-neg.f6478.6

                                                  \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                                              7. Applied rewrites78.6%

                                                \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
                                              8. Taylor expanded in a around 0

                                                \[\leadsto \frac{1}{2 + \color{blue}{a \cdot \left(a \cdot \left(\frac{1}{2} + \frac{-1}{6} \cdot a\right) - 1\right)}} \]
                                              9. Step-by-step derivation
                                                1. Applied rewrites67.7%

                                                  \[\leadsto \frac{1}{\mathsf{fma}\left(a, \color{blue}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right)}, 2\right)} \]

                                                if 6.09999999999999975e57 < b < 1.8999999999999999e154

                                                1. Initial program 100.0%

                                                  \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                2. Add Preprocessing
                                                3. Taylor expanded in a around 0

                                                  \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                4. Step-by-step derivation
                                                  1. lower-/.f64N/A

                                                    \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                  2. lower-+.f64N/A

                                                    \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                                                  3. lower-exp.f64100.0

                                                    \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                                5. Applied rewrites100.0%

                                                  \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                6. Taylor expanded in b around 0

                                                  \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                                7. Step-by-step derivation
                                                  1. Applied rewrites5.7%

                                                    \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, 0.5, 1\right)}, 2\right)} \]
                                                  2. Step-by-step derivation
                                                    1. Applied rewrites88.1%

                                                      \[\leadsto \frac{1}{\frac{\mathsf{fma}\left(\mathsf{fma}\left(b, 0.5, 1\right), b \cdot \mathsf{fma}\left(b, b \cdot 0.5, b\right), -4\right)}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, 0.5, 1\right)}, -2\right)}} \]

                                                    if 1.8999999999999999e154 < b

                                                    1. Initial program 100.0%

                                                      \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                    2. Add Preprocessing
                                                    3. Taylor expanded in a around 0

                                                      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                    4. Step-by-step derivation
                                                      1. lower-/.f64N/A

                                                        \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                      2. lower-+.f64N/A

                                                        \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                                                      3. lower-exp.f64100.0

                                                        \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                                    5. Applied rewrites100.0%

                                                      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                    6. Taylor expanded in b around 0

                                                      \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                                    7. Step-by-step derivation
                                                      1. Applied rewrites100.0%

                                                        \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, 0.5, 1\right)}, 2\right)} \]
                                                      2. Taylor expanded in b around inf

                                                        \[\leadsto \frac{1}{\frac{1}{2} \cdot {b}^{\color{blue}{2}}} \]
                                                      3. Step-by-step derivation
                                                        1. Applied rewrites100.0%

                                                          \[\leadsto \frac{1}{b \cdot \left(b \cdot \color{blue}{0.5}\right)} \]
                                                      4. Recombined 3 regimes into one program.
                                                      5. Add Preprocessing

                                                      Alternative 9: 72.3% accurate, 4.7× speedup?

                                                      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 6.1 \cdot 10^{+57}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\ \mathbf{elif}\;b \leq 1.9 \cdot 10^{+154}:\\ \;\;\;\;\frac{1}{\frac{0.25 \cdot \left(\left(b \cdot b\right) \cdot \left(b \cdot b\right)\right)}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.5, 1\right), -2\right)}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b \cdot \left(b \cdot 0.5\right)}\\ \end{array} \end{array} \]
                                                      (FPCore (a b)
                                                       :precision binary64
                                                       (if (<= b 6.1e+57)
                                                         (/ 1.0 (fma a (fma a (fma a -0.16666666666666666 0.5) -1.0) 2.0))
                                                         (if (<= b 1.9e+154)
                                                           (/ 1.0 (/ (* 0.25 (* (* b b) (* b b))) (fma b (fma b 0.5 1.0) -2.0)))
                                                           (/ 1.0 (* b (* b 0.5))))))
                                                      double code(double a, double b) {
                                                      	double tmp;
                                                      	if (b <= 6.1e+57) {
                                                      		tmp = 1.0 / fma(a, fma(a, fma(a, -0.16666666666666666, 0.5), -1.0), 2.0);
                                                      	} else if (b <= 1.9e+154) {
                                                      		tmp = 1.0 / ((0.25 * ((b * b) * (b * b))) / fma(b, fma(b, 0.5, 1.0), -2.0));
                                                      	} else {
                                                      		tmp = 1.0 / (b * (b * 0.5));
                                                      	}
                                                      	return tmp;
                                                      }
                                                      
                                                      function code(a, b)
                                                      	tmp = 0.0
                                                      	if (b <= 6.1e+57)
                                                      		tmp = Float64(1.0 / fma(a, fma(a, fma(a, -0.16666666666666666, 0.5), -1.0), 2.0));
                                                      	elseif (b <= 1.9e+154)
                                                      		tmp = Float64(1.0 / Float64(Float64(0.25 * Float64(Float64(b * b) * Float64(b * b))) / fma(b, fma(b, 0.5, 1.0), -2.0)));
                                                      	else
                                                      		tmp = Float64(1.0 / Float64(b * Float64(b * 0.5)));
                                                      	end
                                                      	return tmp
                                                      end
                                                      
                                                      code[a_, b_] := If[LessEqual[b, 6.1e+57], N[(1.0 / N[(a * N[(a * N[(a * -0.16666666666666666 + 0.5), $MachinePrecision] + -1.0), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 1.9e+154], N[(1.0 / N[(N[(0.25 * N[(N[(b * b), $MachinePrecision] * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b * N[(b * 0.5 + 1.0), $MachinePrecision] + -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(b * N[(b * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
                                                      
                                                      \begin{array}{l}
                                                      
                                                      \\
                                                      \begin{array}{l}
                                                      \mathbf{if}\;b \leq 6.1 \cdot 10^{+57}:\\
                                                      \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\
                                                      
                                                      \mathbf{elif}\;b \leq 1.9 \cdot 10^{+154}:\\
                                                      \;\;\;\;\frac{1}{\frac{0.25 \cdot \left(\left(b \cdot b\right) \cdot \left(b \cdot b\right)\right)}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.5, 1\right), -2\right)}}\\
                                                      
                                                      \mathbf{else}:\\
                                                      \;\;\;\;\frac{1}{b \cdot \left(b \cdot 0.5\right)}\\
                                                      
                                                      
                                                      \end{array}
                                                      \end{array}
                                                      
                                                      Derivation
                                                      1. Split input into 3 regimes
                                                      2. if b < 6.09999999999999975e57

                                                        1. Initial program 98.5%

                                                          \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                        2. Add Preprocessing
                                                        3. Step-by-step derivation
                                                          1. lift-/.f64N/A

                                                            \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
                                                          2. clear-numN/A

                                                            \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                          3. inv-powN/A

                                                            \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
                                                          4. sqr-powN/A

                                                            \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
                                                          5. pow2N/A

                                                            \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                          6. lower-pow.f64N/A

                                                            \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                          7. lower-pow.f64N/A

                                                            \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
                                                          8. div-invN/A

                                                            \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                          9. lower-*.f64N/A

                                                            \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                          10. lift-exp.f64N/A

                                                            \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                          11. rec-expN/A

                                                            \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                          12. lower-exp.f64N/A

                                                            \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                          13. lower-neg.f64N/A

                                                            \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                          14. metadata-eval97.8

                                                            \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
                                                        4. Applied rewrites97.8%

                                                          \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
                                                        5. Taylor expanded in b around 0

                                                          \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                        6. Step-by-step derivation
                                                          1. lower-/.f64N/A

                                                            \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                          2. +-commutativeN/A

                                                            \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
                                                          3. distribute-lft-inN/A

                                                            \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
                                                          4. exp-negN/A

                                                            \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                          5. lft-mult-inverseN/A

                                                            \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                          6. *-rgt-identityN/A

                                                            \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                          7. lower-+.f64N/A

                                                            \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                                                          8. lower-exp.f64N/A

                                                            \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                          9. lower-neg.f6478.6

                                                            \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                                                        7. Applied rewrites78.6%

                                                          \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
                                                        8. Taylor expanded in a around 0

                                                          \[\leadsto \frac{1}{2 + \color{blue}{a \cdot \left(a \cdot \left(\frac{1}{2} + \frac{-1}{6} \cdot a\right) - 1\right)}} \]
                                                        9. Step-by-step derivation
                                                          1. Applied rewrites67.7%

                                                            \[\leadsto \frac{1}{\mathsf{fma}\left(a, \color{blue}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right)}, 2\right)} \]

                                                          if 6.09999999999999975e57 < b < 1.8999999999999999e154

                                                          1. Initial program 100.0%

                                                            \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                          2. Add Preprocessing
                                                          3. Taylor expanded in a around 0

                                                            \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                          4. Step-by-step derivation
                                                            1. lower-/.f64N/A

                                                              \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                            2. lower-+.f64N/A

                                                              \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                                                            3. lower-exp.f64100.0

                                                              \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                                          5. Applied rewrites100.0%

                                                            \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                          6. Taylor expanded in b around 0

                                                            \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                                          7. Step-by-step derivation
                                                            1. Applied rewrites5.7%

                                                              \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, 0.5, 1\right)}, 2\right)} \]
                                                            2. Step-by-step derivation
                                                              1. Applied rewrites88.1%

                                                                \[\leadsto \frac{1}{\frac{\mathsf{fma}\left(\mathsf{fma}\left(b, 0.5, 1\right), b \cdot \mathsf{fma}\left(b, b \cdot 0.5, b\right), -4\right)}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, 0.5, 1\right)}, -2\right)}} \]
                                                              2. Taylor expanded in b around inf

                                                                \[\leadsto \frac{1}{\frac{\frac{1}{4} \cdot {b}^{4}}{\mathsf{fma}\left(b, \mathsf{fma}\left(\color{blue}{b}, \frac{1}{2}, 1\right), -2\right)}} \]
                                                              3. Step-by-step derivation
                                                                1. Applied rewrites88.1%

                                                                  \[\leadsto \frac{1}{\frac{0.25 \cdot \left(\left(b \cdot b\right) \cdot \left(b \cdot b\right)\right)}{\mathsf{fma}\left(b, \mathsf{fma}\left(\color{blue}{b}, 0.5, 1\right), -2\right)}} \]

                                                                if 1.8999999999999999e154 < b

                                                                1. Initial program 100.0%

                                                                  \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                2. Add Preprocessing
                                                                3. Taylor expanded in a around 0

                                                                  \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                4. Step-by-step derivation
                                                                  1. lower-/.f64N/A

                                                                    \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                  2. lower-+.f64N/A

                                                                    \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                                                                  3. lower-exp.f64100.0

                                                                    \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                                                5. Applied rewrites100.0%

                                                                  \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                6. Taylor expanded in b around 0

                                                                  \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                                                7. Step-by-step derivation
                                                                  1. Applied rewrites100.0%

                                                                    \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, 0.5, 1\right)}, 2\right)} \]
                                                                  2. Taylor expanded in b around inf

                                                                    \[\leadsto \frac{1}{\frac{1}{2} \cdot {b}^{\color{blue}{2}}} \]
                                                                  3. Step-by-step derivation
                                                                    1. Applied rewrites100.0%

                                                                      \[\leadsto \frac{1}{b \cdot \left(b \cdot \color{blue}{0.5}\right)} \]
                                                                  4. Recombined 3 regimes into one program.
                                                                  5. Add Preprocessing

                                                                  Alternative 10: 70.7% accurate, 6.8× speedup?

                                                                  \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 1.02 \cdot 10^{+93}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(b \cdot \left(b \cdot b\right), 0.16666666666666666, \mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.5, 1\right), 2\right)\right)}\\ \end{array} \end{array} \]
                                                                  (FPCore (a b)
                                                                   :precision binary64
                                                                   (if (<= b 1.02e+93)
                                                                     (/ 1.0 (fma a (fma a (fma a -0.16666666666666666 0.5) -1.0) 2.0))
                                                                     (/
                                                                      1.0
                                                                      (fma (* b (* b b)) 0.16666666666666666 (fma b (fma b 0.5 1.0) 2.0)))))
                                                                  double code(double a, double b) {
                                                                  	double tmp;
                                                                  	if (b <= 1.02e+93) {
                                                                  		tmp = 1.0 / fma(a, fma(a, fma(a, -0.16666666666666666, 0.5), -1.0), 2.0);
                                                                  	} else {
                                                                  		tmp = 1.0 / fma((b * (b * b)), 0.16666666666666666, fma(b, fma(b, 0.5, 1.0), 2.0));
                                                                  	}
                                                                  	return tmp;
                                                                  }
                                                                  
                                                                  function code(a, b)
                                                                  	tmp = 0.0
                                                                  	if (b <= 1.02e+93)
                                                                  		tmp = Float64(1.0 / fma(a, fma(a, fma(a, -0.16666666666666666, 0.5), -1.0), 2.0));
                                                                  	else
                                                                  		tmp = Float64(1.0 / fma(Float64(b * Float64(b * b)), 0.16666666666666666, fma(b, fma(b, 0.5, 1.0), 2.0)));
                                                                  	end
                                                                  	return tmp
                                                                  end
                                                                  
                                                                  code[a_, b_] := If[LessEqual[b, 1.02e+93], N[(1.0 / N[(a * N[(a * N[(a * -0.16666666666666666 + 0.5), $MachinePrecision] + -1.0), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision] * 0.16666666666666666 + N[(b * N[(b * 0.5 + 1.0), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
                                                                  
                                                                  \begin{array}{l}
                                                                  
                                                                  \\
                                                                  \begin{array}{l}
                                                                  \mathbf{if}\;b \leq 1.02 \cdot 10^{+93}:\\
                                                                  \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\
                                                                  
                                                                  \mathbf{else}:\\
                                                                  \;\;\;\;\frac{1}{\mathsf{fma}\left(b \cdot \left(b \cdot b\right), 0.16666666666666666, \mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.5, 1\right), 2\right)\right)}\\
                                                                  
                                                                  
                                                                  \end{array}
                                                                  \end{array}
                                                                  
                                                                  Derivation
                                                                  1. Split input into 2 regimes
                                                                  2. if b < 1.0200000000000001e93

                                                                    1. Initial program 98.6%

                                                                      \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                    2. Add Preprocessing
                                                                    3. Step-by-step derivation
                                                                      1. lift-/.f64N/A

                                                                        \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
                                                                      2. clear-numN/A

                                                                        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                                      3. inv-powN/A

                                                                        \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
                                                                      4. sqr-powN/A

                                                                        \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
                                                                      5. pow2N/A

                                                                        \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                      6. lower-pow.f64N/A

                                                                        \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                      7. lower-pow.f64N/A

                                                                        \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
                                                                      8. div-invN/A

                                                                        \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                      9. lower-*.f64N/A

                                                                        \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                      10. lift-exp.f64N/A

                                                                        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                      11. rec-expN/A

                                                                        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                      12. lower-exp.f64N/A

                                                                        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                      13. lower-neg.f64N/A

                                                                        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                      14. metadata-eval97.9

                                                                        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
                                                                    4. Applied rewrites97.9%

                                                                      \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
                                                                    5. Taylor expanded in b around 0

                                                                      \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                    6. Step-by-step derivation
                                                                      1. lower-/.f64N/A

                                                                        \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                      2. +-commutativeN/A

                                                                        \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
                                                                      3. distribute-lft-inN/A

                                                                        \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
                                                                      4. exp-negN/A

                                                                        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                      5. lft-mult-inverseN/A

                                                                        \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                      6. *-rgt-identityN/A

                                                                        \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                      7. lower-+.f64N/A

                                                                        \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                                                                      8. lower-exp.f64N/A

                                                                        \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                      9. lower-neg.f6475.8

                                                                        \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                                                                    7. Applied rewrites75.8%

                                                                      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
                                                                    8. Taylor expanded in a around 0

                                                                      \[\leadsto \frac{1}{2 + \color{blue}{a \cdot \left(a \cdot \left(\frac{1}{2} + \frac{-1}{6} \cdot a\right) - 1\right)}} \]
                                                                    9. Step-by-step derivation
                                                                      1. Applied rewrites65.0%

                                                                        \[\leadsto \frac{1}{\mathsf{fma}\left(a, \color{blue}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right)}, 2\right)} \]

                                                                      if 1.0200000000000001e93 < b

                                                                      1. Initial program 100.0%

                                                                        \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                      2. Add Preprocessing
                                                                      3. Taylor expanded in a around 0

                                                                        \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                      4. Step-by-step derivation
                                                                        1. lower-/.f64N/A

                                                                          \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                        2. lower-+.f64N/A

                                                                          \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                                                                        3. lower-exp.f64100.0

                                                                          \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                                                      5. Applied rewrites100.0%

                                                                        \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                      6. Taylor expanded in b around 0

                                                                        \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + b \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot b\right)\right)}} \]
                                                                      7. Step-by-step derivation
                                                                        1. Applied rewrites91.5%

                                                                          \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right)}, 2\right)} \]
                                                                        2. Step-by-step derivation
                                                                          1. Applied rewrites91.5%

                                                                            \[\leadsto \frac{1}{\mathsf{fma}\left(b, \mathsf{fma}\left(b \cdot b, 0.16666666666666666, \mathsf{fma}\left(b, 0.5, 1\right)\right), 2\right)} \]
                                                                          2. Step-by-step derivation
                                                                            1. Applied rewrites93.5%

                                                                              \[\leadsto \frac{1}{\mathsf{fma}\left(b \cdot \left(b \cdot b\right), 0.16666666666666666, \mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.5, 1\right), 2\right)\right)} \]
                                                                          3. Recombined 2 regimes into one program.
                                                                          4. Add Preprocessing

                                                                          Alternative 11: 70.8% accurate, 8.7× speedup?

                                                                          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 9.5 \cdot 10^{+102}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b \cdot \left(\left(b \cdot b\right) \cdot 0.16666666666666666\right)}\\ \end{array} \end{array} \]
                                                                          (FPCore (a b)
                                                                           :precision binary64
                                                                           (if (<= b 9.5e+102)
                                                                             (/ 1.0 (fma a (fma a (fma a -0.16666666666666666 0.5) -1.0) 2.0))
                                                                             (/ 1.0 (* b (* (* b b) 0.16666666666666666)))))
                                                                          double code(double a, double b) {
                                                                          	double tmp;
                                                                          	if (b <= 9.5e+102) {
                                                                          		tmp = 1.0 / fma(a, fma(a, fma(a, -0.16666666666666666, 0.5), -1.0), 2.0);
                                                                          	} else {
                                                                          		tmp = 1.0 / (b * ((b * b) * 0.16666666666666666));
                                                                          	}
                                                                          	return tmp;
                                                                          }
                                                                          
                                                                          function code(a, b)
                                                                          	tmp = 0.0
                                                                          	if (b <= 9.5e+102)
                                                                          		tmp = Float64(1.0 / fma(a, fma(a, fma(a, -0.16666666666666666, 0.5), -1.0), 2.0));
                                                                          	else
                                                                          		tmp = Float64(1.0 / Float64(b * Float64(Float64(b * b) * 0.16666666666666666)));
                                                                          	end
                                                                          	return tmp
                                                                          end
                                                                          
                                                                          code[a_, b_] := If[LessEqual[b, 9.5e+102], N[(1.0 / N[(a * N[(a * N[(a * -0.16666666666666666 + 0.5), $MachinePrecision] + -1.0), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(b * N[(N[(b * b), $MachinePrecision] * 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
                                                                          
                                                                          \begin{array}{l}
                                                                          
                                                                          \\
                                                                          \begin{array}{l}
                                                                          \mathbf{if}\;b \leq 9.5 \cdot 10^{+102}:\\
                                                                          \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\
                                                                          
                                                                          \mathbf{else}:\\
                                                                          \;\;\;\;\frac{1}{b \cdot \left(\left(b \cdot b\right) \cdot 0.16666666666666666\right)}\\
                                                                          
                                                                          
                                                                          \end{array}
                                                                          \end{array}
                                                                          
                                                                          Derivation
                                                                          1. Split input into 2 regimes
                                                                          2. if b < 9.4999999999999992e102

                                                                            1. Initial program 98.6%

                                                                              \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                            2. Add Preprocessing
                                                                            3. Step-by-step derivation
                                                                              1. lift-/.f64N/A

                                                                                \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
                                                                              2. clear-numN/A

                                                                                \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                                              3. inv-powN/A

                                                                                \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
                                                                              4. sqr-powN/A

                                                                                \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
                                                                              5. pow2N/A

                                                                                \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                              6. lower-pow.f64N/A

                                                                                \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                              7. lower-pow.f64N/A

                                                                                \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
                                                                              8. div-invN/A

                                                                                \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                              9. lower-*.f64N/A

                                                                                \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                              10. lift-exp.f64N/A

                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                              11. rec-expN/A

                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                              12. lower-exp.f64N/A

                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                              13. lower-neg.f64N/A

                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                              14. metadata-eval98.0

                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
                                                                            4. Applied rewrites98.0%

                                                                              \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
                                                                            5. Taylor expanded in b around 0

                                                                              \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                            6. Step-by-step derivation
                                                                              1. lower-/.f64N/A

                                                                                \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                              2. +-commutativeN/A

                                                                                \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
                                                                              3. distribute-lft-inN/A

                                                                                \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
                                                                              4. exp-negN/A

                                                                                \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                              5. lft-mult-inverseN/A

                                                                                \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                              6. *-rgt-identityN/A

                                                                                \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                              7. lower-+.f64N/A

                                                                                \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                                                                              8. lower-exp.f64N/A

                                                                                \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                              9. lower-neg.f6474.9

                                                                                \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                                                                            7. Applied rewrites74.9%

                                                                              \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
                                                                            8. Taylor expanded in a around 0

                                                                              \[\leadsto \frac{1}{2 + \color{blue}{a \cdot \left(a \cdot \left(\frac{1}{2} + \frac{-1}{6} \cdot a\right) - 1\right)}} \]
                                                                            9. Step-by-step derivation
                                                                              1. Applied rewrites64.3%

                                                                                \[\leadsto \frac{1}{\mathsf{fma}\left(a, \color{blue}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right)}, 2\right)} \]

                                                                              if 9.4999999999999992e102 < b

                                                                              1. Initial program 100.0%

                                                                                \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                              2. Add Preprocessing
                                                                              3. Taylor expanded in a around 0

                                                                                \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                              4. Step-by-step derivation
                                                                                1. lower-/.f64N/A

                                                                                  \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                2. lower-+.f64N/A

                                                                                  \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                                                                                3. lower-exp.f64100.0

                                                                                  \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                                                              5. Applied rewrites100.0%

                                                                                \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                              6. Taylor expanded in b around 0

                                                                                \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + b \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot b\right)\right)}} \]
                                                                              7. Step-by-step derivation
                                                                                1. Applied rewrites100.0%

                                                                                  \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right)}, 2\right)} \]
                                                                                2. Taylor expanded in b around inf

                                                                                  \[\leadsto \frac{1}{\frac{1}{6} \cdot {b}^{\color{blue}{3}}} \]
                                                                                3. Step-by-step derivation
                                                                                  1. Applied rewrites100.0%

                                                                                    \[\leadsto \frac{1}{b \cdot \left(0.16666666666666666 \cdot \color{blue}{\left(b \cdot b\right)}\right)} \]
                                                                                4. Recombined 2 regimes into one program.
                                                                                5. Final simplification69.4%

                                                                                  \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 9.5 \cdot 10^{+102}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b \cdot \left(\left(b \cdot b\right) \cdot 0.16666666666666666\right)}\\ \end{array} \]
                                                                                6. Add Preprocessing

                                                                                Alternative 12: 54.7% accurate, 9.0× speedup?

                                                                                \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -1.8 \cdot 10^{+120}:\\ \;\;\;\;\frac{1}{0.5 \cdot \left(a \cdot a\right)}\\ \mathbf{elif}\;a \leq -19:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(b, b \cdot 0.5, b\right)}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a, \mathsf{fma}\left(a, a \cdot -0.020833333333333332, 0.25\right), 0.5\right)\\ \end{array} \end{array} \]
                                                                                (FPCore (a b)
                                                                                 :precision binary64
                                                                                 (if (<= a -1.8e+120)
                                                                                   (/ 1.0 (* 0.5 (* a a)))
                                                                                   (if (<= a -19.0)
                                                                                     (/ 1.0 (fma b (* b 0.5) b))
                                                                                     (fma a (fma a (* a -0.020833333333333332) 0.25) 0.5))))
                                                                                double code(double a, double b) {
                                                                                	double tmp;
                                                                                	if (a <= -1.8e+120) {
                                                                                		tmp = 1.0 / (0.5 * (a * a));
                                                                                	} else if (a <= -19.0) {
                                                                                		tmp = 1.0 / fma(b, (b * 0.5), b);
                                                                                	} else {
                                                                                		tmp = fma(a, fma(a, (a * -0.020833333333333332), 0.25), 0.5);
                                                                                	}
                                                                                	return tmp;
                                                                                }
                                                                                
                                                                                function code(a, b)
                                                                                	tmp = 0.0
                                                                                	if (a <= -1.8e+120)
                                                                                		tmp = Float64(1.0 / Float64(0.5 * Float64(a * a)));
                                                                                	elseif (a <= -19.0)
                                                                                		tmp = Float64(1.0 / fma(b, Float64(b * 0.5), b));
                                                                                	else
                                                                                		tmp = fma(a, fma(a, Float64(a * -0.020833333333333332), 0.25), 0.5);
                                                                                	end
                                                                                	return tmp
                                                                                end
                                                                                
                                                                                code[a_, b_] := If[LessEqual[a, -1.8e+120], N[(1.0 / N[(0.5 * N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[a, -19.0], N[(1.0 / N[(b * N[(b * 0.5), $MachinePrecision] + b), $MachinePrecision]), $MachinePrecision], N[(a * N[(a * N[(a * -0.020833333333333332), $MachinePrecision] + 0.25), $MachinePrecision] + 0.5), $MachinePrecision]]]
                                                                                
                                                                                \begin{array}{l}
                                                                                
                                                                                \\
                                                                                \begin{array}{l}
                                                                                \mathbf{if}\;a \leq -1.8 \cdot 10^{+120}:\\
                                                                                \;\;\;\;\frac{1}{0.5 \cdot \left(a \cdot a\right)}\\
                                                                                
                                                                                \mathbf{elif}\;a \leq -19:\\
                                                                                \;\;\;\;\frac{1}{\mathsf{fma}\left(b, b \cdot 0.5, b\right)}\\
                                                                                
                                                                                \mathbf{else}:\\
                                                                                \;\;\;\;\mathsf{fma}\left(a, \mathsf{fma}\left(a, a \cdot -0.020833333333333332, 0.25\right), 0.5\right)\\
                                                                                
                                                                                
                                                                                \end{array}
                                                                                \end{array}
                                                                                
                                                                                Derivation
                                                                                1. Split input into 3 regimes
                                                                                2. if a < -1.80000000000000008e120

                                                                                  1. Initial program 100.0%

                                                                                    \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                  2. Add Preprocessing
                                                                                  3. Step-by-step derivation
                                                                                    1. lift-/.f64N/A

                                                                                      \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
                                                                                    2. clear-numN/A

                                                                                      \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                                                    3. inv-powN/A

                                                                                      \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
                                                                                    4. sqr-powN/A

                                                                                      \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
                                                                                    5. pow2N/A

                                                                                      \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                    6. lower-pow.f64N/A

                                                                                      \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                    7. lower-pow.f64N/A

                                                                                      \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
                                                                                    8. div-invN/A

                                                                                      \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                    9. lower-*.f64N/A

                                                                                      \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                    10. lift-exp.f64N/A

                                                                                      \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                    11. rec-expN/A

                                                                                      \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                    12. lower-exp.f64N/A

                                                                                      \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                    13. lower-neg.f64N/A

                                                                                      \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                    14. metadata-eval100.0

                                                                                      \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
                                                                                  4. Applied rewrites100.0%

                                                                                    \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
                                                                                  5. Taylor expanded in b around 0

                                                                                    \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                  6. Step-by-step derivation
                                                                                    1. lower-/.f64N/A

                                                                                      \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                    2. +-commutativeN/A

                                                                                      \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
                                                                                    3. distribute-lft-inN/A

                                                                                      \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
                                                                                    4. exp-negN/A

                                                                                      \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                    5. lft-mult-inverseN/A

                                                                                      \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                    6. *-rgt-identityN/A

                                                                                      \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                    7. lower-+.f64N/A

                                                                                      \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                    8. lower-exp.f64N/A

                                                                                      \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                    9. lower-neg.f64100.0

                                                                                      \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                                                                                  7. Applied rewrites100.0%

                                                                                    \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
                                                                                  8. Taylor expanded in a around 0

                                                                                    \[\leadsto \frac{1}{2 + \color{blue}{a \cdot \left(\frac{1}{2} \cdot a - 1\right)}} \]
                                                                                  9. Step-by-step derivation
                                                                                    1. Applied rewrites86.3%

                                                                                      \[\leadsto \frac{1}{\mathsf{fma}\left(a, \color{blue}{\mathsf{fma}\left(a, 0.5, -1\right)}, 2\right)} \]
                                                                                    2. Taylor expanded in a around inf

                                                                                      \[\leadsto \frac{1}{\frac{1}{2} \cdot {a}^{\color{blue}{2}}} \]
                                                                                    3. Step-by-step derivation
                                                                                      1. Applied rewrites86.3%

                                                                                        \[\leadsto \frac{1}{0.5 \cdot \left(a \cdot \color{blue}{a}\right)} \]

                                                                                      if -1.80000000000000008e120 < a < -19

                                                                                      1. Initial program 96.6%

                                                                                        \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                      2. Add Preprocessing
                                                                                      3. Taylor expanded in a around 0

                                                                                        \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                      4. Step-by-step derivation
                                                                                        1. lower-/.f64N/A

                                                                                          \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                        2. lower-+.f64N/A

                                                                                          \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                                                                                        3. lower-exp.f6436.5

                                                                                          \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                                                                      5. Applied rewrites36.5%

                                                                                        \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                      6. Taylor expanded in b around 0

                                                                                        \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                                                                      7. Step-by-step derivation
                                                                                        1. Applied rewrites26.7%

                                                                                          \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, 0.5, 1\right)}, 2\right)} \]
                                                                                        2. Taylor expanded in b around inf

                                                                                          \[\leadsto \frac{1}{{b}^{2} \cdot \left(\frac{1}{2} + \color{blue}{\frac{1}{b}}\right)} \]
                                                                                        3. Step-by-step derivation
                                                                                          1. Applied rewrites26.1%

                                                                                            \[\leadsto \frac{1}{\mathsf{fma}\left(b, b \cdot \color{blue}{0.5}, b\right)} \]

                                                                                          if -19 < a

                                                                                          1. Initial program 98.9%

                                                                                            \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                          2. Add Preprocessing
                                                                                          3. Step-by-step derivation
                                                                                            1. lift-/.f64N/A

                                                                                              \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
                                                                                            2. clear-numN/A

                                                                                              \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                                                            3. inv-powN/A

                                                                                              \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
                                                                                            4. sqr-powN/A

                                                                                              \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
                                                                                            5. pow2N/A

                                                                                              \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                            6. lower-pow.f64N/A

                                                                                              \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                            7. lower-pow.f64N/A

                                                                                              \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
                                                                                            8. div-invN/A

                                                                                              \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                            9. lower-*.f64N/A

                                                                                              \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                            10. lift-exp.f64N/A

                                                                                              \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                            11. rec-expN/A

                                                                                              \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                            12. lower-exp.f64N/A

                                                                                              \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                            13. lower-neg.f64N/A

                                                                                              \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                            14. metadata-eval98.1

                                                                                              \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
                                                                                          4. Applied rewrites98.1%

                                                                                            \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
                                                                                          5. Taylor expanded in b around 0

                                                                                            \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                          6. Step-by-step derivation
                                                                                            1. lower-/.f64N/A

                                                                                              \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                            2. +-commutativeN/A

                                                                                              \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
                                                                                            3. distribute-lft-inN/A

                                                                                              \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
                                                                                            4. exp-negN/A

                                                                                              \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                            5. lft-mult-inverseN/A

                                                                                              \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                            6. *-rgt-identityN/A

                                                                                              \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                            7. lower-+.f64N/A

                                                                                              \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                            8. lower-exp.f64N/A

                                                                                              \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                            9. lower-neg.f6461.3

                                                                                              \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                                                                                          7. Applied rewrites61.3%

                                                                                            \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
                                                                                          8. Taylor expanded in a around 0

                                                                                            \[\leadsto \frac{1}{2} + \color{blue}{a \cdot \left(\frac{1}{4} + \frac{-1}{48} \cdot {a}^{2}\right)} \]
                                                                                          9. Step-by-step derivation
                                                                                            1. Applied rewrites58.6%

                                                                                              \[\leadsto \mathsf{fma}\left(a, \color{blue}{\mathsf{fma}\left(a, a \cdot -0.020833333333333332, 0.25\right)}, 0.5\right) \]
                                                                                          10. Recombined 3 regimes into one program.
                                                                                          11. Add Preprocessing

                                                                                          Alternative 13: 54.6% accurate, 9.3× speedup?

                                                                                          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -1.8 \cdot 10^{+120}:\\ \;\;\;\;\frac{1}{0.5 \cdot \left(a \cdot a\right)}\\ \mathbf{elif}\;a \leq -18:\\ \;\;\;\;\frac{1}{b \cdot \left(b \cdot 0.5\right)}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a, \mathsf{fma}\left(a, a \cdot -0.020833333333333332, 0.25\right), 0.5\right)\\ \end{array} \end{array} \]
                                                                                          (FPCore (a b)
                                                                                           :precision binary64
                                                                                           (if (<= a -1.8e+120)
                                                                                             (/ 1.0 (* 0.5 (* a a)))
                                                                                             (if (<= a -18.0)
                                                                                               (/ 1.0 (* b (* b 0.5)))
                                                                                               (fma a (fma a (* a -0.020833333333333332) 0.25) 0.5))))
                                                                                          double code(double a, double b) {
                                                                                          	double tmp;
                                                                                          	if (a <= -1.8e+120) {
                                                                                          		tmp = 1.0 / (0.5 * (a * a));
                                                                                          	} else if (a <= -18.0) {
                                                                                          		tmp = 1.0 / (b * (b * 0.5));
                                                                                          	} else {
                                                                                          		tmp = fma(a, fma(a, (a * -0.020833333333333332), 0.25), 0.5);
                                                                                          	}
                                                                                          	return tmp;
                                                                                          }
                                                                                          
                                                                                          function code(a, b)
                                                                                          	tmp = 0.0
                                                                                          	if (a <= -1.8e+120)
                                                                                          		tmp = Float64(1.0 / Float64(0.5 * Float64(a * a)));
                                                                                          	elseif (a <= -18.0)
                                                                                          		tmp = Float64(1.0 / Float64(b * Float64(b * 0.5)));
                                                                                          	else
                                                                                          		tmp = fma(a, fma(a, Float64(a * -0.020833333333333332), 0.25), 0.5);
                                                                                          	end
                                                                                          	return tmp
                                                                                          end
                                                                                          
                                                                                          code[a_, b_] := If[LessEqual[a, -1.8e+120], N[(1.0 / N[(0.5 * N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[a, -18.0], N[(1.0 / N[(b * N[(b * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(a * N[(a * N[(a * -0.020833333333333332), $MachinePrecision] + 0.25), $MachinePrecision] + 0.5), $MachinePrecision]]]
                                                                                          
                                                                                          \begin{array}{l}
                                                                                          
                                                                                          \\
                                                                                          \begin{array}{l}
                                                                                          \mathbf{if}\;a \leq -1.8 \cdot 10^{+120}:\\
                                                                                          \;\;\;\;\frac{1}{0.5 \cdot \left(a \cdot a\right)}\\
                                                                                          
                                                                                          \mathbf{elif}\;a \leq -18:\\
                                                                                          \;\;\;\;\frac{1}{b \cdot \left(b \cdot 0.5\right)}\\
                                                                                          
                                                                                          \mathbf{else}:\\
                                                                                          \;\;\;\;\mathsf{fma}\left(a, \mathsf{fma}\left(a, a \cdot -0.020833333333333332, 0.25\right), 0.5\right)\\
                                                                                          
                                                                                          
                                                                                          \end{array}
                                                                                          \end{array}
                                                                                          
                                                                                          Derivation
                                                                                          1. Split input into 3 regimes
                                                                                          2. if a < -1.80000000000000008e120

                                                                                            1. Initial program 100.0%

                                                                                              \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                            2. Add Preprocessing
                                                                                            3. Step-by-step derivation
                                                                                              1. lift-/.f64N/A

                                                                                                \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
                                                                                              2. clear-numN/A

                                                                                                \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                                                              3. inv-powN/A

                                                                                                \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
                                                                                              4. sqr-powN/A

                                                                                                \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
                                                                                              5. pow2N/A

                                                                                                \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                              6. lower-pow.f64N/A

                                                                                                \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                              7. lower-pow.f64N/A

                                                                                                \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
                                                                                              8. div-invN/A

                                                                                                \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                              9. lower-*.f64N/A

                                                                                                \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                              10. lift-exp.f64N/A

                                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                              11. rec-expN/A

                                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                              12. lower-exp.f64N/A

                                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                              13. lower-neg.f64N/A

                                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                              14. metadata-eval100.0

                                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
                                                                                            4. Applied rewrites100.0%

                                                                                              \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
                                                                                            5. Taylor expanded in b around 0

                                                                                              \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                            6. Step-by-step derivation
                                                                                              1. lower-/.f64N/A

                                                                                                \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                              2. +-commutativeN/A

                                                                                                \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
                                                                                              3. distribute-lft-inN/A

                                                                                                \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
                                                                                              4. exp-negN/A

                                                                                                \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                              5. lft-mult-inverseN/A

                                                                                                \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                              6. *-rgt-identityN/A

                                                                                                \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                              7. lower-+.f64N/A

                                                                                                \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                              8. lower-exp.f64N/A

                                                                                                \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                              9. lower-neg.f64100.0

                                                                                                \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                                                                                            7. Applied rewrites100.0%

                                                                                              \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
                                                                                            8. Taylor expanded in a around 0

                                                                                              \[\leadsto \frac{1}{2 + \color{blue}{a \cdot \left(\frac{1}{2} \cdot a - 1\right)}} \]
                                                                                            9. Step-by-step derivation
                                                                                              1. Applied rewrites86.3%

                                                                                                \[\leadsto \frac{1}{\mathsf{fma}\left(a, \color{blue}{\mathsf{fma}\left(a, 0.5, -1\right)}, 2\right)} \]
                                                                                              2. Taylor expanded in a around inf

                                                                                                \[\leadsto \frac{1}{\frac{1}{2} \cdot {a}^{\color{blue}{2}}} \]
                                                                                              3. Step-by-step derivation
                                                                                                1. Applied rewrites86.3%

                                                                                                  \[\leadsto \frac{1}{0.5 \cdot \left(a \cdot \color{blue}{a}\right)} \]

                                                                                                if -1.80000000000000008e120 < a < -18

                                                                                                1. Initial program 96.6%

                                                                                                  \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                                2. Add Preprocessing
                                                                                                3. Taylor expanded in a around 0

                                                                                                  \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                                4. Step-by-step derivation
                                                                                                  1. lower-/.f64N/A

                                                                                                    \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                                  2. lower-+.f64N/A

                                                                                                    \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                                                                                                  3. lower-exp.f6436.5

                                                                                                    \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                                                                                5. Applied rewrites36.5%

                                                                                                  \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                                6. Taylor expanded in b around 0

                                                                                                  \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                                                                                7. Step-by-step derivation
                                                                                                  1. Applied rewrites26.7%

                                                                                                    \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, 0.5, 1\right)}, 2\right)} \]
                                                                                                  2. Taylor expanded in b around inf

                                                                                                    \[\leadsto \frac{1}{\frac{1}{2} \cdot {b}^{\color{blue}{2}}} \]
                                                                                                  3. Step-by-step derivation
                                                                                                    1. Applied rewrites25.9%

                                                                                                      \[\leadsto \frac{1}{b \cdot \left(b \cdot \color{blue}{0.5}\right)} \]

                                                                                                    if -18 < a

                                                                                                    1. Initial program 98.9%

                                                                                                      \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                                    2. Add Preprocessing
                                                                                                    3. Step-by-step derivation
                                                                                                      1. lift-/.f64N/A

                                                                                                        \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
                                                                                                      2. clear-numN/A

                                                                                                        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                                                                      3. inv-powN/A

                                                                                                        \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
                                                                                                      4. sqr-powN/A

                                                                                                        \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
                                                                                                      5. pow2N/A

                                                                                                        \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                                      6. lower-pow.f64N/A

                                                                                                        \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                                      7. lower-pow.f64N/A

                                                                                                        \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
                                                                                                      8. div-invN/A

                                                                                                        \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                      9. lower-*.f64N/A

                                                                                                        \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                      10. lift-exp.f64N/A

                                                                                                        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                      11. rec-expN/A

                                                                                                        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                      12. lower-exp.f64N/A

                                                                                                        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                      13. lower-neg.f64N/A

                                                                                                        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                      14. metadata-eval98.1

                                                                                                        \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
                                                                                                    4. Applied rewrites98.1%

                                                                                                      \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
                                                                                                    5. Taylor expanded in b around 0

                                                                                                      \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                                    6. Step-by-step derivation
                                                                                                      1. lower-/.f64N/A

                                                                                                        \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                                      2. +-commutativeN/A

                                                                                                        \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
                                                                                                      3. distribute-lft-inN/A

                                                                                                        \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
                                                                                                      4. exp-negN/A

                                                                                                        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                                      5. lft-mult-inverseN/A

                                                                                                        \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                                      6. *-rgt-identityN/A

                                                                                                        \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                      7. lower-+.f64N/A

                                                                                                        \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                      8. lower-exp.f64N/A

                                                                                                        \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                      9. lower-neg.f6461.3

                                                                                                        \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                                                                                                    7. Applied rewrites61.3%

                                                                                                      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
                                                                                                    8. Taylor expanded in a around 0

                                                                                                      \[\leadsto \frac{1}{2} + \color{blue}{a \cdot \left(\frac{1}{4} + \frac{-1}{48} \cdot {a}^{2}\right)} \]
                                                                                                    9. Step-by-step derivation
                                                                                                      1. Applied rewrites58.6%

                                                                                                        \[\leadsto \mathsf{fma}\left(a, \color{blue}{\mathsf{fma}\left(a, a \cdot -0.020833333333333332, 0.25\right)}, 0.5\right) \]
                                                                                                    10. Recombined 3 regimes into one program.
                                                                                                    11. Add Preprocessing

                                                                                                    Alternative 14: 67.4% accurate, 9.5× speedup?

                                                                                                    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 8.2 \cdot 10^{+102}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, 0.5, -1\right), 2\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b \cdot \left(\left(b \cdot b\right) \cdot 0.16666666666666666\right)}\\ \end{array} \end{array} \]
                                                                                                    (FPCore (a b)
                                                                                                     :precision binary64
                                                                                                     (if (<= b 8.2e+102)
                                                                                                       (/ 1.0 (fma a (fma a 0.5 -1.0) 2.0))
                                                                                                       (/ 1.0 (* b (* (* b b) 0.16666666666666666)))))
                                                                                                    double code(double a, double b) {
                                                                                                    	double tmp;
                                                                                                    	if (b <= 8.2e+102) {
                                                                                                    		tmp = 1.0 / fma(a, fma(a, 0.5, -1.0), 2.0);
                                                                                                    	} else {
                                                                                                    		tmp = 1.0 / (b * ((b * b) * 0.16666666666666666));
                                                                                                    	}
                                                                                                    	return tmp;
                                                                                                    }
                                                                                                    
                                                                                                    function code(a, b)
                                                                                                    	tmp = 0.0
                                                                                                    	if (b <= 8.2e+102)
                                                                                                    		tmp = Float64(1.0 / fma(a, fma(a, 0.5, -1.0), 2.0));
                                                                                                    	else
                                                                                                    		tmp = Float64(1.0 / Float64(b * Float64(Float64(b * b) * 0.16666666666666666)));
                                                                                                    	end
                                                                                                    	return tmp
                                                                                                    end
                                                                                                    
                                                                                                    code[a_, b_] := If[LessEqual[b, 8.2e+102], N[(1.0 / N[(a * N[(a * 0.5 + -1.0), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(b * N[(N[(b * b), $MachinePrecision] * 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
                                                                                                    
                                                                                                    \begin{array}{l}
                                                                                                    
                                                                                                    \\
                                                                                                    \begin{array}{l}
                                                                                                    \mathbf{if}\;b \leq 8.2 \cdot 10^{+102}:\\
                                                                                                    \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, 0.5, -1\right), 2\right)}\\
                                                                                                    
                                                                                                    \mathbf{else}:\\
                                                                                                    \;\;\;\;\frac{1}{b \cdot \left(\left(b \cdot b\right) \cdot 0.16666666666666666\right)}\\
                                                                                                    
                                                                                                    
                                                                                                    \end{array}
                                                                                                    \end{array}
                                                                                                    
                                                                                                    Derivation
                                                                                                    1. Split input into 2 regimes
                                                                                                    2. if b < 8.1999999999999999e102

                                                                                                      1. Initial program 98.6%

                                                                                                        \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                                      2. Add Preprocessing
                                                                                                      3. Step-by-step derivation
                                                                                                        1. lift-/.f64N/A

                                                                                                          \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
                                                                                                        2. clear-numN/A

                                                                                                          \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                                                                        3. inv-powN/A

                                                                                                          \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
                                                                                                        4. sqr-powN/A

                                                                                                          \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
                                                                                                        5. pow2N/A

                                                                                                          \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                                        6. lower-pow.f64N/A

                                                                                                          \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                                        7. lower-pow.f64N/A

                                                                                                          \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
                                                                                                        8. div-invN/A

                                                                                                          \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                        9. lower-*.f64N/A

                                                                                                          \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                        10. lift-exp.f64N/A

                                                                                                          \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                        11. rec-expN/A

                                                                                                          \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                        12. lower-exp.f64N/A

                                                                                                          \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                        13. lower-neg.f64N/A

                                                                                                          \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                        14. metadata-eval98.0

                                                                                                          \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
                                                                                                      4. Applied rewrites98.0%

                                                                                                        \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
                                                                                                      5. Taylor expanded in b around 0

                                                                                                        \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                                      6. Step-by-step derivation
                                                                                                        1. lower-/.f64N/A

                                                                                                          \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                                        2. +-commutativeN/A

                                                                                                          \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
                                                                                                        3. distribute-lft-inN/A

                                                                                                          \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
                                                                                                        4. exp-negN/A

                                                                                                          \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                                        5. lft-mult-inverseN/A

                                                                                                          \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                                        6. *-rgt-identityN/A

                                                                                                          \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                        7. lower-+.f64N/A

                                                                                                          \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                        8. lower-exp.f64N/A

                                                                                                          \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                        9. lower-neg.f6474.9

                                                                                                          \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                                                                                                      7. Applied rewrites74.9%

                                                                                                        \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
                                                                                                      8. Taylor expanded in a around 0

                                                                                                        \[\leadsto \frac{1}{2 + \color{blue}{a \cdot \left(\frac{1}{2} \cdot a - 1\right)}} \]
                                                                                                      9. Step-by-step derivation
                                                                                                        1. Applied rewrites59.9%

                                                                                                          \[\leadsto \frac{1}{\mathsf{fma}\left(a, \color{blue}{\mathsf{fma}\left(a, 0.5, -1\right)}, 2\right)} \]

                                                                                                        if 8.1999999999999999e102 < b

                                                                                                        1. Initial program 100.0%

                                                                                                          \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                                        2. Add Preprocessing
                                                                                                        3. Taylor expanded in a around 0

                                                                                                          \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                                        4. Step-by-step derivation
                                                                                                          1. lower-/.f64N/A

                                                                                                            \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                                          2. lower-+.f64N/A

                                                                                                            \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                                                                                                          3. lower-exp.f64100.0

                                                                                                            \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                                                                                        5. Applied rewrites100.0%

                                                                                                          \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                                        6. Taylor expanded in b around 0

                                                                                                          \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + b \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot b\right)\right)}} \]
                                                                                                        7. Step-by-step derivation
                                                                                                          1. Applied rewrites100.0%

                                                                                                            \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right)}, 2\right)} \]
                                                                                                          2. Taylor expanded in b around inf

                                                                                                            \[\leadsto \frac{1}{\frac{1}{6} \cdot {b}^{\color{blue}{3}}} \]
                                                                                                          3. Step-by-step derivation
                                                                                                            1. Applied rewrites100.0%

                                                                                                              \[\leadsto \frac{1}{b \cdot \left(0.16666666666666666 \cdot \color{blue}{\left(b \cdot b\right)}\right)} \]
                                                                                                          4. Recombined 2 regimes into one program.
                                                                                                          5. Final simplification65.7%

                                                                                                            \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 8.2 \cdot 10^{+102}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, 0.5, -1\right), 2\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b \cdot \left(\left(b \cdot b\right) \cdot 0.16666666666666666\right)}\\ \end{array} \]
                                                                                                          6. Add Preprocessing

                                                                                                          Alternative 15: 63.7% accurate, 10.5× speedup?

                                                                                                          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 1.55 \cdot 10^{+151}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, 0.5, -1\right), 2\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b \cdot \left(b \cdot 0.5\right)}\\ \end{array} \end{array} \]
                                                                                                          (FPCore (a b)
                                                                                                           :precision binary64
                                                                                                           (if (<= b 1.55e+151)
                                                                                                             (/ 1.0 (fma a (fma a 0.5 -1.0) 2.0))
                                                                                                             (/ 1.0 (* b (* b 0.5)))))
                                                                                                          double code(double a, double b) {
                                                                                                          	double tmp;
                                                                                                          	if (b <= 1.55e+151) {
                                                                                                          		tmp = 1.0 / fma(a, fma(a, 0.5, -1.0), 2.0);
                                                                                                          	} else {
                                                                                                          		tmp = 1.0 / (b * (b * 0.5));
                                                                                                          	}
                                                                                                          	return tmp;
                                                                                                          }
                                                                                                          
                                                                                                          function code(a, b)
                                                                                                          	tmp = 0.0
                                                                                                          	if (b <= 1.55e+151)
                                                                                                          		tmp = Float64(1.0 / fma(a, fma(a, 0.5, -1.0), 2.0));
                                                                                                          	else
                                                                                                          		tmp = Float64(1.0 / Float64(b * Float64(b * 0.5)));
                                                                                                          	end
                                                                                                          	return tmp
                                                                                                          end
                                                                                                          
                                                                                                          code[a_, b_] := If[LessEqual[b, 1.55e+151], N[(1.0 / N[(a * N[(a * 0.5 + -1.0), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(b * N[(b * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
                                                                                                          
                                                                                                          \begin{array}{l}
                                                                                                          
                                                                                                          \\
                                                                                                          \begin{array}{l}
                                                                                                          \mathbf{if}\;b \leq 1.55 \cdot 10^{+151}:\\
                                                                                                          \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, 0.5, -1\right), 2\right)}\\
                                                                                                          
                                                                                                          \mathbf{else}:\\
                                                                                                          \;\;\;\;\frac{1}{b \cdot \left(b \cdot 0.5\right)}\\
                                                                                                          
                                                                                                          
                                                                                                          \end{array}
                                                                                                          \end{array}
                                                                                                          
                                                                                                          Derivation
                                                                                                          1. Split input into 2 regimes
                                                                                                          2. if b < 1.5500000000000001e151

                                                                                                            1. Initial program 98.7%

                                                                                                              \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                                            2. Add Preprocessing
                                                                                                            3. Step-by-step derivation
                                                                                                              1. lift-/.f64N/A

                                                                                                                \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
                                                                                                              2. clear-numN/A

                                                                                                                \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                                                                              3. inv-powN/A

                                                                                                                \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
                                                                                                              4. sqr-powN/A

                                                                                                                \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
                                                                                                              5. pow2N/A

                                                                                                                \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                                              6. lower-pow.f64N/A

                                                                                                                \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                                              7. lower-pow.f64N/A

                                                                                                                \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
                                                                                                              8. div-invN/A

                                                                                                                \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                              9. lower-*.f64N/A

                                                                                                                \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                              10. lift-exp.f64N/A

                                                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                              11. rec-expN/A

                                                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                              12. lower-exp.f64N/A

                                                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                              13. lower-neg.f64N/A

                                                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                              14. metadata-eval98.0

                                                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
                                                                                                            4. Applied rewrites98.0%

                                                                                                              \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
                                                                                                            5. Taylor expanded in b around 0

                                                                                                              \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                                            6. Step-by-step derivation
                                                                                                              1. lower-/.f64N/A

                                                                                                                \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                                              2. +-commutativeN/A

                                                                                                                \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
                                                                                                              3. distribute-lft-inN/A

                                                                                                                \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
                                                                                                              4. exp-negN/A

                                                                                                                \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                                              5. lft-mult-inverseN/A

                                                                                                                \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                                              6. *-rgt-identityN/A

                                                                                                                \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                              7. lower-+.f64N/A

                                                                                                                \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                              8. lower-exp.f64N/A

                                                                                                                \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                              9. lower-neg.f6473.2

                                                                                                                \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                                                                                                            7. Applied rewrites73.2%

                                                                                                              \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
                                                                                                            8. Taylor expanded in a around 0

                                                                                                              \[\leadsto \frac{1}{2 + \color{blue}{a \cdot \left(\frac{1}{2} \cdot a - 1\right)}} \]
                                                                                                            9. Step-by-step derivation
                                                                                                              1. Applied rewrites58.8%

                                                                                                                \[\leadsto \frac{1}{\mathsf{fma}\left(a, \color{blue}{\mathsf{fma}\left(a, 0.5, -1\right)}, 2\right)} \]

                                                                                                              if 1.5500000000000001e151 < b

                                                                                                              1. Initial program 100.0%

                                                                                                                \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                                              2. Add Preprocessing
                                                                                                              3. Taylor expanded in a around 0

                                                                                                                \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                                              4. Step-by-step derivation
                                                                                                                1. lower-/.f64N/A

                                                                                                                  \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                                                2. lower-+.f64N/A

                                                                                                                  \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                                                                                                                3. lower-exp.f64100.0

                                                                                                                  \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                                                                                              5. Applied rewrites100.0%

                                                                                                                \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                                              6. Taylor expanded in b around 0

                                                                                                                \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                                                                                              7. Step-by-step derivation
                                                                                                                1. Applied rewrites100.0%

                                                                                                                  \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, 0.5, 1\right)}, 2\right)} \]
                                                                                                                2. Taylor expanded in b around inf

                                                                                                                  \[\leadsto \frac{1}{\frac{1}{2} \cdot {b}^{\color{blue}{2}}} \]
                                                                                                                3. Step-by-step derivation
                                                                                                                  1. Applied rewrites100.0%

                                                                                                                    \[\leadsto \frac{1}{b \cdot \left(b \cdot \color{blue}{0.5}\right)} \]
                                                                                                                4. Recombined 2 regimes into one program.
                                                                                                                5. Add Preprocessing

                                                                                                                Alternative 16: 60.8% accurate, 10.5× speedup?

                                                                                                                \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -1.8 \cdot 10^{+120}:\\ \;\;\;\;\frac{1}{0.5 \cdot \left(a \cdot a\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.5, 1\right), 2\right)}\\ \end{array} \end{array} \]
                                                                                                                (FPCore (a b)
                                                                                                                 :precision binary64
                                                                                                                 (if (<= a -1.8e+120)
                                                                                                                   (/ 1.0 (* 0.5 (* a a)))
                                                                                                                   (/ 1.0 (fma b (fma b 0.5 1.0) 2.0))))
                                                                                                                double code(double a, double b) {
                                                                                                                	double tmp;
                                                                                                                	if (a <= -1.8e+120) {
                                                                                                                		tmp = 1.0 / (0.5 * (a * a));
                                                                                                                	} else {
                                                                                                                		tmp = 1.0 / fma(b, fma(b, 0.5, 1.0), 2.0);
                                                                                                                	}
                                                                                                                	return tmp;
                                                                                                                }
                                                                                                                
                                                                                                                function code(a, b)
                                                                                                                	tmp = 0.0
                                                                                                                	if (a <= -1.8e+120)
                                                                                                                		tmp = Float64(1.0 / Float64(0.5 * Float64(a * a)));
                                                                                                                	else
                                                                                                                		tmp = Float64(1.0 / fma(b, fma(b, 0.5, 1.0), 2.0));
                                                                                                                	end
                                                                                                                	return tmp
                                                                                                                end
                                                                                                                
                                                                                                                code[a_, b_] := If[LessEqual[a, -1.8e+120], N[(1.0 / N[(0.5 * N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(b * N[(b * 0.5 + 1.0), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision]]
                                                                                                                
                                                                                                                \begin{array}{l}
                                                                                                                
                                                                                                                \\
                                                                                                                \begin{array}{l}
                                                                                                                \mathbf{if}\;a \leq -1.8 \cdot 10^{+120}:\\
                                                                                                                \;\;\;\;\frac{1}{0.5 \cdot \left(a \cdot a\right)}\\
                                                                                                                
                                                                                                                \mathbf{else}:\\
                                                                                                                \;\;\;\;\frac{1}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.5, 1\right), 2\right)}\\
                                                                                                                
                                                                                                                
                                                                                                                \end{array}
                                                                                                                \end{array}
                                                                                                                
                                                                                                                Derivation
                                                                                                                1. Split input into 2 regimes
                                                                                                                2. if a < -1.80000000000000008e120

                                                                                                                  1. Initial program 100.0%

                                                                                                                    \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                                                  2. Add Preprocessing
                                                                                                                  3. Step-by-step derivation
                                                                                                                    1. lift-/.f64N/A

                                                                                                                      \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
                                                                                                                    2. clear-numN/A

                                                                                                                      \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                                                                                    3. inv-powN/A

                                                                                                                      \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
                                                                                                                    4. sqr-powN/A

                                                                                                                      \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
                                                                                                                    5. pow2N/A

                                                                                                                      \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                                                    6. lower-pow.f64N/A

                                                                                                                      \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                                                    7. lower-pow.f64N/A

                                                                                                                      \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
                                                                                                                    8. div-invN/A

                                                                                                                      \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                    9. lower-*.f64N/A

                                                                                                                      \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                    10. lift-exp.f64N/A

                                                                                                                      \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                    11. rec-expN/A

                                                                                                                      \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                    12. lower-exp.f64N/A

                                                                                                                      \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                    13. lower-neg.f64N/A

                                                                                                                      \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                    14. metadata-eval100.0

                                                                                                                      \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
                                                                                                                  4. Applied rewrites100.0%

                                                                                                                    \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
                                                                                                                  5. Taylor expanded in b around 0

                                                                                                                    \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                                                  6. Step-by-step derivation
                                                                                                                    1. lower-/.f64N/A

                                                                                                                      \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                                                    2. +-commutativeN/A

                                                                                                                      \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
                                                                                                                    3. distribute-lft-inN/A

                                                                                                                      \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
                                                                                                                    4. exp-negN/A

                                                                                                                      \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                                                    5. lft-mult-inverseN/A

                                                                                                                      \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                                                    6. *-rgt-identityN/A

                                                                                                                      \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                                    7. lower-+.f64N/A

                                                                                                                      \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                                    8. lower-exp.f64N/A

                                                                                                                      \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                                    9. lower-neg.f64100.0

                                                                                                                      \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                                                                                                                  7. Applied rewrites100.0%

                                                                                                                    \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
                                                                                                                  8. Taylor expanded in a around 0

                                                                                                                    \[\leadsto \frac{1}{2 + \color{blue}{a \cdot \left(\frac{1}{2} \cdot a - 1\right)}} \]
                                                                                                                  9. Step-by-step derivation
                                                                                                                    1. Applied rewrites86.3%

                                                                                                                      \[\leadsto \frac{1}{\mathsf{fma}\left(a, \color{blue}{\mathsf{fma}\left(a, 0.5, -1\right)}, 2\right)} \]
                                                                                                                    2. Taylor expanded in a around inf

                                                                                                                      \[\leadsto \frac{1}{\frac{1}{2} \cdot {a}^{\color{blue}{2}}} \]
                                                                                                                    3. Step-by-step derivation
                                                                                                                      1. Applied rewrites86.3%

                                                                                                                        \[\leadsto \frac{1}{0.5 \cdot \left(a \cdot \color{blue}{a}\right)} \]

                                                                                                                      if -1.80000000000000008e120 < a

                                                                                                                      1. Initial program 98.5%

                                                                                                                        \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                                                      2. Add Preprocessing
                                                                                                                      3. Taylor expanded in a around 0

                                                                                                                        \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                                                      4. Step-by-step derivation
                                                                                                                        1. lower-/.f64N/A

                                                                                                                          \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                                                        2. lower-+.f64N/A

                                                                                                                          \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                                                                                                                        3. lower-exp.f6488.7

                                                                                                                          \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                                                                                                      5. Applied rewrites88.7%

                                                                                                                        \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                                                      6. Taylor expanded in b around 0

                                                                                                                        \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                                                                                                      7. Step-by-step derivation
                                                                                                                        1. Applied rewrites55.5%

                                                                                                                          \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, 0.5, 1\right)}, 2\right)} \]
                                                                                                                      8. Recombined 2 regimes into one program.
                                                                                                                      9. Add Preprocessing

                                                                                                                      Alternative 17: 53.0% accurate, 11.2× speedup?

                                                                                                                      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 1.95:\\ \;\;\;\;\frac{1}{2 - a}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b \cdot \left(b \cdot 0.5\right)}\\ \end{array} \end{array} \]
                                                                                                                      (FPCore (a b)
                                                                                                                       :precision binary64
                                                                                                                       (if (<= b 1.95) (/ 1.0 (- 2.0 a)) (/ 1.0 (* b (* b 0.5)))))
                                                                                                                      double code(double a, double b) {
                                                                                                                      	double tmp;
                                                                                                                      	if (b <= 1.95) {
                                                                                                                      		tmp = 1.0 / (2.0 - a);
                                                                                                                      	} else {
                                                                                                                      		tmp = 1.0 / (b * (b * 0.5));
                                                                                                                      	}
                                                                                                                      	return tmp;
                                                                                                                      }
                                                                                                                      
                                                                                                                      real(8) function code(a, b)
                                                                                                                          real(8), intent (in) :: a
                                                                                                                          real(8), intent (in) :: b
                                                                                                                          real(8) :: tmp
                                                                                                                          if (b <= 1.95d0) then
                                                                                                                              tmp = 1.0d0 / (2.0d0 - a)
                                                                                                                          else
                                                                                                                              tmp = 1.0d0 / (b * (b * 0.5d0))
                                                                                                                          end if
                                                                                                                          code = tmp
                                                                                                                      end function
                                                                                                                      
                                                                                                                      public static double code(double a, double b) {
                                                                                                                      	double tmp;
                                                                                                                      	if (b <= 1.95) {
                                                                                                                      		tmp = 1.0 / (2.0 - a);
                                                                                                                      	} else {
                                                                                                                      		tmp = 1.0 / (b * (b * 0.5));
                                                                                                                      	}
                                                                                                                      	return tmp;
                                                                                                                      }
                                                                                                                      
                                                                                                                      def code(a, b):
                                                                                                                      	tmp = 0
                                                                                                                      	if b <= 1.95:
                                                                                                                      		tmp = 1.0 / (2.0 - a)
                                                                                                                      	else:
                                                                                                                      		tmp = 1.0 / (b * (b * 0.5))
                                                                                                                      	return tmp
                                                                                                                      
                                                                                                                      function code(a, b)
                                                                                                                      	tmp = 0.0
                                                                                                                      	if (b <= 1.95)
                                                                                                                      		tmp = Float64(1.0 / Float64(2.0 - a));
                                                                                                                      	else
                                                                                                                      		tmp = Float64(1.0 / Float64(b * Float64(b * 0.5)));
                                                                                                                      	end
                                                                                                                      	return tmp
                                                                                                                      end
                                                                                                                      
                                                                                                                      function tmp_2 = code(a, b)
                                                                                                                      	tmp = 0.0;
                                                                                                                      	if (b <= 1.95)
                                                                                                                      		tmp = 1.0 / (2.0 - a);
                                                                                                                      	else
                                                                                                                      		tmp = 1.0 / (b * (b * 0.5));
                                                                                                                      	end
                                                                                                                      	tmp_2 = tmp;
                                                                                                                      end
                                                                                                                      
                                                                                                                      code[a_, b_] := If[LessEqual[b, 1.95], N[(1.0 / N[(2.0 - a), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(b * N[(b * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
                                                                                                                      
                                                                                                                      \begin{array}{l}
                                                                                                                      
                                                                                                                      \\
                                                                                                                      \begin{array}{l}
                                                                                                                      \mathbf{if}\;b \leq 1.95:\\
                                                                                                                      \;\;\;\;\frac{1}{2 - a}\\
                                                                                                                      
                                                                                                                      \mathbf{else}:\\
                                                                                                                      \;\;\;\;\frac{1}{b \cdot \left(b \cdot 0.5\right)}\\
                                                                                                                      
                                                                                                                      
                                                                                                                      \end{array}
                                                                                                                      \end{array}
                                                                                                                      
                                                                                                                      Derivation
                                                                                                                      1. Split input into 2 regimes
                                                                                                                      2. if b < 1.94999999999999996

                                                                                                                        1. Initial program 98.4%

                                                                                                                          \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                                                        2. Add Preprocessing
                                                                                                                        3. Step-by-step derivation
                                                                                                                          1. lift-/.f64N/A

                                                                                                                            \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
                                                                                                                          2. clear-numN/A

                                                                                                                            \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                                                                                          3. inv-powN/A

                                                                                                                            \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
                                                                                                                          4. sqr-powN/A

                                                                                                                            \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
                                                                                                                          5. pow2N/A

                                                                                                                            \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                                                          6. lower-pow.f64N/A

                                                                                                                            \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                                                          7. lower-pow.f64N/A

                                                                                                                            \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
                                                                                                                          8. div-invN/A

                                                                                                                            \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                          9. lower-*.f64N/A

                                                                                                                            \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                          10. lift-exp.f64N/A

                                                                                                                            \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                          11. rec-expN/A

                                                                                                                            \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                          12. lower-exp.f64N/A

                                                                                                                            \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                          13. lower-neg.f64N/A

                                                                                                                            \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                          14. metadata-eval97.7

                                                                                                                            \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
                                                                                                                        4. Applied rewrites97.7%

                                                                                                                          \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
                                                                                                                        5. Taylor expanded in b around 0

                                                                                                                          \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                                                        6. Step-by-step derivation
                                                                                                                          1. lower-/.f64N/A

                                                                                                                            \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                                                          2. +-commutativeN/A

                                                                                                                            \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
                                                                                                                          3. distribute-lft-inN/A

                                                                                                                            \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
                                                                                                                          4. exp-negN/A

                                                                                                                            \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                                                          5. lft-mult-inverseN/A

                                                                                                                            \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                                                          6. *-rgt-identityN/A

                                                                                                                            \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                                          7. lower-+.f64N/A

                                                                                                                            \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                                          8. lower-exp.f64N/A

                                                                                                                            \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                                          9. lower-neg.f6480.3

                                                                                                                            \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                                                                                                                        7. Applied rewrites80.3%

                                                                                                                          \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
                                                                                                                        8. Taylor expanded in a around 0

                                                                                                                          \[\leadsto \frac{1}{2 + \color{blue}{-1 \cdot a}} \]
                                                                                                                        9. Step-by-step derivation
                                                                                                                          1. Applied rewrites54.2%

                                                                                                                            \[\leadsto \frac{1}{2 - \color{blue}{a}} \]

                                                                                                                          if 1.94999999999999996 < b

                                                                                                                          1. Initial program 100.0%

                                                                                                                            \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                                                          2. Add Preprocessing
                                                                                                                          3. Taylor expanded in a around 0

                                                                                                                            \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                                                          4. Step-by-step derivation
                                                                                                                            1. lower-/.f64N/A

                                                                                                                              \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                                                            2. lower-+.f64N/A

                                                                                                                              \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                                                                                                                            3. lower-exp.f64100.0

                                                                                                                              \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                                                                                                          5. Applied rewrites100.0%

                                                                                                                            \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                                                          6. Taylor expanded in b around 0

                                                                                                                            \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                                                                                                          7. Step-by-step derivation
                                                                                                                            1. Applied rewrites51.1%

                                                                                                                              \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, 0.5, 1\right)}, 2\right)} \]
                                                                                                                            2. Taylor expanded in b around inf

                                                                                                                              \[\leadsto \frac{1}{\frac{1}{2} \cdot {b}^{\color{blue}{2}}} \]
                                                                                                                            3. Step-by-step derivation
                                                                                                                              1. Applied rewrites51.1%

                                                                                                                                \[\leadsto \frac{1}{b \cdot \left(b \cdot \color{blue}{0.5}\right)} \]
                                                                                                                            4. Recombined 2 regimes into one program.
                                                                                                                            5. Add Preprocessing

                                                                                                                            Alternative 18: 40.1% accurate, 21.0× speedup?

                                                                                                                            \[\begin{array}{l} \\ \frac{1}{2 - a} \end{array} \]
                                                                                                                            (FPCore (a b) :precision binary64 (/ 1.0 (- 2.0 a)))
                                                                                                                            double code(double a, double b) {
                                                                                                                            	return 1.0 / (2.0 - a);
                                                                                                                            }
                                                                                                                            
                                                                                                                            real(8) function code(a, b)
                                                                                                                                real(8), intent (in) :: a
                                                                                                                                real(8), intent (in) :: b
                                                                                                                                code = 1.0d0 / (2.0d0 - a)
                                                                                                                            end function
                                                                                                                            
                                                                                                                            public static double code(double a, double b) {
                                                                                                                            	return 1.0 / (2.0 - a);
                                                                                                                            }
                                                                                                                            
                                                                                                                            def code(a, b):
                                                                                                                            	return 1.0 / (2.0 - a)
                                                                                                                            
                                                                                                                            function code(a, b)
                                                                                                                            	return Float64(1.0 / Float64(2.0 - a))
                                                                                                                            end
                                                                                                                            
                                                                                                                            function tmp = code(a, b)
                                                                                                                            	tmp = 1.0 / (2.0 - a);
                                                                                                                            end
                                                                                                                            
                                                                                                                            code[a_, b_] := N[(1.0 / N[(2.0 - a), $MachinePrecision]), $MachinePrecision]
                                                                                                                            
                                                                                                                            \begin{array}{l}
                                                                                                                            
                                                                                                                            \\
                                                                                                                            \frac{1}{2 - a}
                                                                                                                            \end{array}
                                                                                                                            
                                                                                                                            Derivation
                                                                                                                            1. Initial program 98.8%

                                                                                                                              \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                                                            2. Add Preprocessing
                                                                                                                            3. Step-by-step derivation
                                                                                                                              1. lift-/.f64N/A

                                                                                                                                \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
                                                                                                                              2. clear-numN/A

                                                                                                                                \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                                                                                              3. inv-powN/A

                                                                                                                                \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
                                                                                                                              4. sqr-powN/A

                                                                                                                                \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
                                                                                                                              5. pow2N/A

                                                                                                                                \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                                                              6. lower-pow.f64N/A

                                                                                                                                \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                                                              7. lower-pow.f64N/A

                                                                                                                                \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
                                                                                                                              8. div-invN/A

                                                                                                                                \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                              9. lower-*.f64N/A

                                                                                                                                \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                              10. lift-exp.f64N/A

                                                                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                              11. rec-expN/A

                                                                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                              12. lower-exp.f64N/A

                                                                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                              13. lower-neg.f64N/A

                                                                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                              14. metadata-eval98.2

                                                                                                                                \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
                                                                                                                            4. Applied rewrites98.2%

                                                                                                                              \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
                                                                                                                            5. Taylor expanded in b around 0

                                                                                                                              \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                                                            6. Step-by-step derivation
                                                                                                                              1. lower-/.f64N/A

                                                                                                                                \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                                                              2. +-commutativeN/A

                                                                                                                                \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
                                                                                                                              3. distribute-lft-inN/A

                                                                                                                                \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
                                                                                                                              4. exp-negN/A

                                                                                                                                \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                                                              5. lft-mult-inverseN/A

                                                                                                                                \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                                                              6. *-rgt-identityN/A

                                                                                                                                \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                                              7. lower-+.f64N/A

                                                                                                                                \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                                              8. lower-exp.f64N/A

                                                                                                                                \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                                              9. lower-neg.f6472.4

                                                                                                                                \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                                                                                                                            7. Applied rewrites72.4%

                                                                                                                              \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
                                                                                                                            8. Taylor expanded in a around 0

                                                                                                                              \[\leadsto \frac{1}{2 + \color{blue}{-1 \cdot a}} \]
                                                                                                                            9. Step-by-step derivation
                                                                                                                              1. Applied rewrites42.5%

                                                                                                                                \[\leadsto \frac{1}{2 - \color{blue}{a}} \]
                                                                                                                              2. Add Preprocessing

                                                                                                                              Alternative 19: 39.4% accurate, 45.0× speedup?

                                                                                                                              \[\begin{array}{l} \\ \mathsf{fma}\left(a, 0.25, 0.5\right) \end{array} \]
                                                                                                                              (FPCore (a b) :precision binary64 (fma a 0.25 0.5))
                                                                                                                              double code(double a, double b) {
                                                                                                                              	return fma(a, 0.25, 0.5);
                                                                                                                              }
                                                                                                                              
                                                                                                                              function code(a, b)
                                                                                                                              	return fma(a, 0.25, 0.5)
                                                                                                                              end
                                                                                                                              
                                                                                                                              code[a_, b_] := N[(a * 0.25 + 0.5), $MachinePrecision]
                                                                                                                              
                                                                                                                              \begin{array}{l}
                                                                                                                              
                                                                                                                              \\
                                                                                                                              \mathsf{fma}\left(a, 0.25, 0.5\right)
                                                                                                                              \end{array}
                                                                                                                              
                                                                                                                              Derivation
                                                                                                                              1. Initial program 98.8%

                                                                                                                                \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                                                              2. Add Preprocessing
                                                                                                                              3. Step-by-step derivation
                                                                                                                                1. lift-/.f64N/A

                                                                                                                                  \[\leadsto \color{blue}{\frac{e^{a}}{e^{a} + e^{b}}} \]
                                                                                                                                2. clear-numN/A

                                                                                                                                  \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                                                                                                3. inv-powN/A

                                                                                                                                  \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{-1}} \]
                                                                                                                                4. sqr-powN/A

                                                                                                                                  \[\leadsto \color{blue}{{\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)} \cdot {\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}} \]
                                                                                                                                5. pow2N/A

                                                                                                                                  \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                                                                6. lower-pow.f64N/A

                                                                                                                                  \[\leadsto \color{blue}{{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2}} \]
                                                                                                                                7. lower-pow.f64N/A

                                                                                                                                  \[\leadsto {\color{blue}{\left({\left(\frac{e^{a} + e^{b}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}}^{2} \]
                                                                                                                                8. div-invN/A

                                                                                                                                  \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                                9. lower-*.f64N/A

                                                                                                                                  \[\leadsto {\left({\color{blue}{\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}\right)}}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                                10. lift-exp.f64N/A

                                                                                                                                  \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \frac{1}{\color{blue}{e^{a}}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                                11. rec-expN/A

                                                                                                                                  \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                                12. lower-exp.f64N/A

                                                                                                                                  \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                                13. lower-neg.f64N/A

                                                                                                                                  \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{\mathsf{neg}\left(a\right)}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
                                                                                                                                14. metadata-eval98.2

                                                                                                                                  \[\leadsto {\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
                                                                                                                              4. Applied rewrites98.2%

                                                                                                                                \[\leadsto \color{blue}{{\left({\left(\left(e^{a} + e^{b}\right) \cdot e^{-a}\right)}^{-0.5}\right)}^{2}} \]
                                                                                                                              5. Taylor expanded in b around 0

                                                                                                                                \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                                                              6. Step-by-step derivation
                                                                                                                                1. lower-/.f64N/A

                                                                                                                                  \[\leadsto \color{blue}{\frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \left(1 + e^{a}\right)}} \]
                                                                                                                                2. +-commutativeN/A

                                                                                                                                  \[\leadsto \frac{1}{e^{\mathsf{neg}\left(a\right)} \cdot \color{blue}{\left(e^{a} + 1\right)}} \]
                                                                                                                                3. distribute-lft-inN/A

                                                                                                                                  \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1}} \]
                                                                                                                                4. exp-negN/A

                                                                                                                                  \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}}} \cdot e^{a} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                                                                5. lft-mult-inverseN/A

                                                                                                                                  \[\leadsto \frac{1}{\color{blue}{1} + e^{\mathsf{neg}\left(a\right)} \cdot 1} \]
                                                                                                                                6. *-rgt-identityN/A

                                                                                                                                  \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                                                7. lower-+.f64N/A

                                                                                                                                  \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                                                8. lower-exp.f64N/A

                                                                                                                                  \[\leadsto \frac{1}{1 + \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                                                                9. lower-neg.f6472.4

                                                                                                                                  \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                                                                                                                              7. Applied rewrites72.4%

                                                                                                                                \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
                                                                                                                              8. Taylor expanded in a around 0

                                                                                                                                \[\leadsto \frac{1}{2} + \color{blue}{\frac{1}{4} \cdot a} \]
                                                                                                                              9. Step-by-step derivation
                                                                                                                                1. Applied rewrites41.7%

                                                                                                                                  \[\leadsto \mathsf{fma}\left(a, \color{blue}{0.25}, 0.5\right) \]
                                                                                                                                2. Add Preprocessing

                                                                                                                                Alternative 20: 39.2% accurate, 315.0× speedup?

                                                                                                                                \[\begin{array}{l} \\ 0.5 \end{array} \]
                                                                                                                                (FPCore (a b) :precision binary64 0.5)
                                                                                                                                double code(double a, double b) {
                                                                                                                                	return 0.5;
                                                                                                                                }
                                                                                                                                
                                                                                                                                real(8) function code(a, b)
                                                                                                                                    real(8), intent (in) :: a
                                                                                                                                    real(8), intent (in) :: b
                                                                                                                                    code = 0.5d0
                                                                                                                                end function
                                                                                                                                
                                                                                                                                public static double code(double a, double b) {
                                                                                                                                	return 0.5;
                                                                                                                                }
                                                                                                                                
                                                                                                                                def code(a, b):
                                                                                                                                	return 0.5
                                                                                                                                
                                                                                                                                function code(a, b)
                                                                                                                                	return 0.5
                                                                                                                                end
                                                                                                                                
                                                                                                                                function tmp = code(a, b)
                                                                                                                                	tmp = 0.5;
                                                                                                                                end
                                                                                                                                
                                                                                                                                code[a_, b_] := 0.5
                                                                                                                                
                                                                                                                                \begin{array}{l}
                                                                                                                                
                                                                                                                                \\
                                                                                                                                0.5
                                                                                                                                \end{array}
                                                                                                                                
                                                                                                                                Derivation
                                                                                                                                1. Initial program 98.8%

                                                                                                                                  \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                                                                2. Add Preprocessing
                                                                                                                                3. Taylor expanded in a around 0

                                                                                                                                  \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                                                                4. Step-by-step derivation
                                                                                                                                  1. lower-/.f64N/A

                                                                                                                                    \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                                                                  2. lower-+.f64N/A

                                                                                                                                    \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
                                                                                                                                  3. lower-exp.f6479.8

                                                                                                                                    \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                                                                                                                5. Applied rewrites79.8%

                                                                                                                                  \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                                                                                6. Taylor expanded in b around 0

                                                                                                                                  \[\leadsto \frac{1}{2} \]
                                                                                                                                7. Step-by-step derivation
                                                                                                                                  1. Applied rewrites41.7%

                                                                                                                                    \[\leadsto 0.5 \]
                                                                                                                                  2. Add Preprocessing

                                                                                                                                  Developer Target 1: 100.0% accurate, 2.7× speedup?

                                                                                                                                  \[\begin{array}{l} \\ \frac{1}{1 + e^{b - a}} \end{array} \]
                                                                                                                                  (FPCore (a b) :precision binary64 (/ 1.0 (+ 1.0 (exp (- b a)))))
                                                                                                                                  double code(double a, double b) {
                                                                                                                                  	return 1.0 / (1.0 + exp((b - a)));
                                                                                                                                  }
                                                                                                                                  
                                                                                                                                  real(8) function code(a, b)
                                                                                                                                      real(8), intent (in) :: a
                                                                                                                                      real(8), intent (in) :: b
                                                                                                                                      code = 1.0d0 / (1.0d0 + exp((b - a)))
                                                                                                                                  end function
                                                                                                                                  
                                                                                                                                  public static double code(double a, double b) {
                                                                                                                                  	return 1.0 / (1.0 + Math.exp((b - a)));
                                                                                                                                  }
                                                                                                                                  
                                                                                                                                  def code(a, b):
                                                                                                                                  	return 1.0 / (1.0 + math.exp((b - a)))
                                                                                                                                  
                                                                                                                                  function code(a, b)
                                                                                                                                  	return Float64(1.0 / Float64(1.0 + exp(Float64(b - a))))
                                                                                                                                  end
                                                                                                                                  
                                                                                                                                  function tmp = code(a, b)
                                                                                                                                  	tmp = 1.0 / (1.0 + exp((b - a)));
                                                                                                                                  end
                                                                                                                                  
                                                                                                                                  code[a_, b_] := N[(1.0 / N[(1.0 + N[Exp[N[(b - a), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
                                                                                                                                  
                                                                                                                                  \begin{array}{l}
                                                                                                                                  
                                                                                                                                  \\
                                                                                                                                  \frac{1}{1 + e^{b - a}}
                                                                                                                                  \end{array}
                                                                                                                                  

                                                                                                                                  Reproduce

                                                                                                                                  ?
                                                                                                                                  herbie shell --seed 2024234 
                                                                                                                                  (FPCore (a b)
                                                                                                                                    :name "Quotient of sum of exps"
                                                                                                                                    :precision binary64
                                                                                                                                  
                                                                                                                                    :alt
                                                                                                                                    (! :herbie-platform default (/ 1 (+ 1 (exp (- b a)))))
                                                                                                                                  
                                                                                                                                    (/ (exp a) (+ (exp a) (exp b))))