Quotient of sum of exps

Percentage Accurate: 98.9% → 98.3%
Time: 11.3s
Alternatives: 16
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 16 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: 98.3% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{a} \leq 0.998:\\ \;\;\;\;\frac{1}{1 + e^{-a}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{e^{b} + 1}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= (exp a) 0.998) (/ 1.0 (+ 1.0 (exp (- a)))) (/ 1.0 (+ (exp b) 1.0))))
double code(double a, double b) {
	double tmp;
	if (exp(a) <= 0.998) {
		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) <= 0.998d0) 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) <= 0.998) {
		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) <= 0.998:
		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) <= 0.998)
		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) <= 0.998)
		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], 0.998], 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 0.998:\\
\;\;\;\;\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) < 0.998

    1. Initial program 96.8%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    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. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. div-invN/A

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

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

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

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

        \[\leadsto \frac{1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
      9. lower-neg.f6496.8

        \[\leadsto \frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{-a}}} \]
    4. Applied rewrites96.8%

      \[\leadsto \color{blue}{\frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
    5. Taylor expanded in b around 0

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{1 + e^{\color{blue}{-1 \cdot a}}} \]
      8. lower-exp.f64N/A

        \[\leadsto \frac{1}{1 + \color{blue}{e^{-1 \cdot a}}} \]
      9. neg-mul-1N/A

        \[\leadsto \frac{1}{1 + e^{\color{blue}{\mathsf{neg}\left(a\right)}}} \]
      10. lower-neg.f6498.4

        \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
    7. Applied rewrites98.4%

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

    if 0.998 < (exp.f64 a)

    1. Initial program 98.4%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    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.f6499.4

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
    5. Applied rewrites99.4%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;e^{a} \leq 0.998:\\ \;\;\;\;\frac{1}{1 + e^{-a}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{e^{b} + 1}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 99.1% accurate, 0.8× speedup?

\[\begin{array}{l} \\ e^{\mathsf{fma}\left(\log \left(e^{a} + e^{b}\right), -1, a\right)} \end{array} \]
(FPCore (a b) :precision binary64 (exp (fma (log (+ (exp a) (exp b))) -1.0 a)))
double code(double a, double b) {
	return exp(fma(log((exp(a) + exp(b))), -1.0, a));
}
function code(a, b)
	return exp(fma(log(Float64(exp(a) + exp(b))), -1.0, a))
end
code[a_, b_] := N[Exp[N[(N[Log[N[(N[Exp[a], $MachinePrecision] + N[Exp[b], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * -1.0 + a), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
e^{\mathsf{fma}\left(\log \left(e^{a} + e^{b}\right), -1, a\right)}
\end{array}
Derivation
  1. Initial program 98.0%

    \[\frac{e^{a}}{e^{a} + e^{b}} \]
  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. associate-/r/N/A

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

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

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

      \[\leadsto e^{\log \left(e^{a} + e^{b}\right) \cdot -1} \cdot \color{blue}{e^{a}} \]
    7. prod-expN/A

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

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

      \[\leadsto e^{\color{blue}{\mathsf{fma}\left(\log \left(e^{a} + e^{b}\right), -1, a\right)}} \]
    10. lower-log.f6498.8

      \[\leadsto e^{\mathsf{fma}\left(\color{blue}{\log \left(e^{a} + e^{b}\right)}, -1, a\right)} \]
  4. Applied rewrites98.8%

    \[\leadsto \color{blue}{e^{\mathsf{fma}\left(\log \left(e^{a} + e^{b}\right), -1, a\right)}} \]
  5. Add Preprocessing

Alternative 3: 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 98.0%

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

Alternative 4: 94.1% accurate, 2.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right)\\ t_1 := a \cdot t\_0\\ \mathbf{if}\;a \leq -1 \cdot 10^{+119}:\\ \;\;\;\;\frac{1}{a \cdot \left(-0.16666666666666666 \cdot \left(a \cdot a\right)\right)}\\ \mathbf{elif}\;a \leq -1 \cdot 10^{+61}:\\ \;\;\;\;\frac{1}{\frac{\mathsf{fma}\left(t\_1, t\_1, -4\right)}{\mathsf{fma}\left(a, t\_0, -2\right)}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{e^{b} + 1}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (let* ((t_0 (fma a (fma a -0.16666666666666666 0.5) -1.0)) (t_1 (* a t_0)))
   (if (<= a -1e+119)
     (/ 1.0 (* a (* -0.16666666666666666 (* a a))))
     (if (<= a -1e+61)
       (/ 1.0 (/ (fma t_1 t_1 -4.0) (fma a t_0 -2.0)))
       (/ 1.0 (+ (exp b) 1.0))))))
double code(double a, double b) {
	double t_0 = fma(a, fma(a, -0.16666666666666666, 0.5), -1.0);
	double t_1 = a * t_0;
	double tmp;
	if (a <= -1e+119) {
		tmp = 1.0 / (a * (-0.16666666666666666 * (a * a)));
	} else if (a <= -1e+61) {
		tmp = 1.0 / (fma(t_1, t_1, -4.0) / fma(a, t_0, -2.0));
	} else {
		tmp = 1.0 / (exp(b) + 1.0);
	}
	return tmp;
}
function code(a, b)
	t_0 = fma(a, fma(a, -0.16666666666666666, 0.5), -1.0)
	t_1 = Float64(a * t_0)
	tmp = 0.0
	if (a <= -1e+119)
		tmp = Float64(1.0 / Float64(a * Float64(-0.16666666666666666 * Float64(a * a))));
	elseif (a <= -1e+61)
		tmp = Float64(1.0 / Float64(fma(t_1, t_1, -4.0) / fma(a, t_0, -2.0)));
	else
		tmp = Float64(1.0 / Float64(exp(b) + 1.0));
	end
	return tmp
end
code[a_, b_] := Block[{t$95$0 = N[(a * N[(a * -0.16666666666666666 + 0.5), $MachinePrecision] + -1.0), $MachinePrecision]}, Block[{t$95$1 = N[(a * t$95$0), $MachinePrecision]}, If[LessEqual[a, -1e+119], N[(1.0 / N[(a * N[(-0.16666666666666666 * N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[a, -1e+61], N[(1.0 / N[(N[(t$95$1 * t$95$1 + -4.0), $MachinePrecision] / N[(a * t$95$0 + -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[Exp[b], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right)\\
t_1 := a \cdot t\_0\\
\mathbf{if}\;a \leq -1 \cdot 10^{+119}:\\
\;\;\;\;\frac{1}{a \cdot \left(-0.16666666666666666 \cdot \left(a \cdot a\right)\right)}\\

\mathbf{elif}\;a \leq -1 \cdot 10^{+61}:\\
\;\;\;\;\frac{1}{\frac{\mathsf{fma}\left(t\_1, t\_1, -4\right)}{\mathsf{fma}\left(a, t\_0, -2\right)}}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if a < -9.99999999999999944e118

    1. Initial program 97.6%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    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. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. div-invN/A

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

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

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

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

        \[\leadsto \frac{1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
      9. lower-neg.f6497.6

        \[\leadsto \frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{-a}}} \]
    4. Applied rewrites97.6%

      \[\leadsto \color{blue}{\frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
    5. Taylor expanded in b around 0

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{1 + e^{\color{blue}{-1 \cdot a}}} \]
      8. lower-exp.f64N/A

        \[\leadsto \frac{1}{1 + \color{blue}{e^{-1 \cdot a}}} \]
      9. neg-mul-1N/A

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

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

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

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

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

          \[\leadsto \frac{1}{a \cdot \left(-0.16666666666666666 \cdot \color{blue}{\left(a \cdot a\right)}\right)} \]

        if -9.99999999999999944e118 < a < -9.99999999999999949e60

        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. lower-/.f64N/A

            \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
          4. div-invN/A

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

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

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

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

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

            \[\leadsto \frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{-a}}} \]
        4. Applied rewrites100.0%

          \[\leadsto \color{blue}{\frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
        5. Taylor expanded in b around 0

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

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

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

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

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

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

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

            \[\leadsto \frac{1}{1 + e^{\color{blue}{-1 \cdot a}}} \]
          8. lower-exp.f64N/A

            \[\leadsto \frac{1}{1 + \color{blue}{e^{-1 \cdot a}}} \]
          9. neg-mul-1N/A

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

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

          \[\leadsto \frac{1}{\color{blue}{1 + e^{-a}}} \]
        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 rewrites6.7%

            \[\leadsto \frac{1}{\mathsf{fma}\left(a, \color{blue}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right)}, 2\right)} \]
          2. Step-by-step derivation
            1. Applied rewrites100.0%

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

            if -9.99999999999999949e60 < a

            1. Initial program 98.0%

              \[\frac{e^{a}}{e^{a} + e^{b}} \]
            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.f6496.4

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

              \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
          3. Recombined 3 regimes into one program.
          4. Final simplification97.1%

            \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -1 \cdot 10^{+119}:\\ \;\;\;\;\frac{1}{a \cdot \left(-0.16666666666666666 \cdot \left(a \cdot a\right)\right)}\\ \mathbf{elif}\;a \leq -1 \cdot 10^{+61}:\\ \;\;\;\;\frac{1}{\frac{\mathsf{fma}\left(a \cdot \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), a \cdot \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), -4\right)}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), -2\right)}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{e^{b} + 1}\\ \end{array} \]
          5. Add Preprocessing

          Alternative 5: 97.5% accurate, 2.6× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -5 \cdot 10^{+25}:\\ \;\;\;\;\frac{e^{a}}{1 + 1}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{e^{b} + 1}\\ \end{array} \end{array} \]
          (FPCore (a b)
           :precision binary64
           (if (<= a -5e+25) (/ (exp a) (+ 1.0 1.0)) (/ 1.0 (+ (exp b) 1.0))))
          double code(double a, double b) {
          	double tmp;
          	if (a <= -5e+25) {
          		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 (a <= (-5d+25)) 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 (a <= -5e+25) {
          		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 a <= -5e+25:
          		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 (a <= -5e+25)
          		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 (a <= -5e+25)
          		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[a, -5e+25], 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}\;a \leq -5 \cdot 10^{+25}:\\
          \;\;\;\;\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 a < -5.00000000000000024e25

            1. Initial program 98.3%

              \[\frac{e^{a}}{e^{a} + e^{b}} \]
            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 -5.00000000000000024e25 < a

                1. Initial program 97.9%

                  \[\frac{e^{a}}{e^{a} + e^{b}} \]
                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.f6498.7

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

                  \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
              4. Recombined 2 regimes into one program.
              5. Final simplification99.0%

                \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -5 \cdot 10^{+25}:\\ \;\;\;\;\frac{e^{a}}{1 + 1}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{e^{b} + 1}\\ \end{array} \]
              6. Add Preprocessing

              Alternative 6: 88.0% accurate, 2.9× speedup?

              \[\begin{array}{l} \\ \begin{array}{l} t_0 := \mathsf{fma}\left(b, b \cdot \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), b\right)\\ \mathbf{if}\;b \leq -20000:\\ \;\;\;\;e^{b} + 1\\ \mathbf{elif}\;b \leq 4 \cdot 10^{+21}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\ \mathbf{elif}\;b \leq 2 \cdot 10^{+89}:\\ \;\;\;\;\frac{1}{\frac{\mathsf{fma}\left(t\_0, t\_0, -4\right)}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right), -2\right)}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b \cdot \left(0.16666666666666666 \cdot \left(b \cdot b\right)\right)}\\ \end{array} \end{array} \]
              (FPCore (a b)
               :precision binary64
               (let* ((t_0 (fma b (* b (fma b 0.16666666666666666 0.5)) b)))
                 (if (<= b -20000.0)
                   (+ (exp b) 1.0)
                   (if (<= b 4e+21)
                     (/ 1.0 (fma a (fma a (fma a -0.16666666666666666 0.5) -1.0) 2.0))
                     (if (<= b 2e+89)
                       (/
                        1.0
                        (/
                         (fma t_0 t_0 -4.0)
                         (fma b (fma b (fma b 0.16666666666666666 0.5) 1.0) -2.0)))
                       (/ 1.0 (* b (* 0.16666666666666666 (* b b)))))))))
              double code(double a, double b) {
              	double t_0 = fma(b, (b * fma(b, 0.16666666666666666, 0.5)), b);
              	double tmp;
              	if (b <= -20000.0) {
              		tmp = exp(b) + 1.0;
              	} else if (b <= 4e+21) {
              		tmp = 1.0 / fma(a, fma(a, fma(a, -0.16666666666666666, 0.5), -1.0), 2.0);
              	} else if (b <= 2e+89) {
              		tmp = 1.0 / (fma(t_0, t_0, -4.0) / fma(b, fma(b, fma(b, 0.16666666666666666, 0.5), 1.0), -2.0));
              	} else {
              		tmp = 1.0 / (b * (0.16666666666666666 * (b * b)));
              	}
              	return tmp;
              }
              
              function code(a, b)
              	t_0 = fma(b, Float64(b * fma(b, 0.16666666666666666, 0.5)), b)
              	tmp = 0.0
              	if (b <= -20000.0)
              		tmp = Float64(exp(b) + 1.0);
              	elseif (b <= 4e+21)
              		tmp = Float64(1.0 / fma(a, fma(a, fma(a, -0.16666666666666666, 0.5), -1.0), 2.0));
              	elseif (b <= 2e+89)
              		tmp = Float64(1.0 / Float64(fma(t_0, t_0, -4.0) / fma(b, fma(b, fma(b, 0.16666666666666666, 0.5), 1.0), -2.0)));
              	else
              		tmp = Float64(1.0 / Float64(b * Float64(0.16666666666666666 * Float64(b * b))));
              	end
              	return tmp
              end
              
              code[a_, b_] := Block[{t$95$0 = N[(b * N[(b * N[(b * 0.16666666666666666 + 0.5), $MachinePrecision]), $MachinePrecision] + b), $MachinePrecision]}, If[LessEqual[b, -20000.0], N[(N[Exp[b], $MachinePrecision] + 1.0), $MachinePrecision], If[LessEqual[b, 4e+21], N[(1.0 / N[(a * N[(a * N[(a * -0.16666666666666666 + 0.5), $MachinePrecision] + -1.0), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 2e+89], N[(1.0 / N[(N[(t$95$0 * t$95$0 + -4.0), $MachinePrecision] / N[(b * N[(b * N[(b * 0.16666666666666666 + 0.5), $MachinePrecision] + 1.0), $MachinePrecision] + -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(b * N[(0.16666666666666666 * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]]
              
              \begin{array}{l}
              
              \\
              \begin{array}{l}
              t_0 := \mathsf{fma}\left(b, b \cdot \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), b\right)\\
              \mathbf{if}\;b \leq -20000:\\
              \;\;\;\;e^{b} + 1\\
              
              \mathbf{elif}\;b \leq 4 \cdot 10^{+21}:\\
              \;\;\;\;\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 2 \cdot 10^{+89}:\\
              \;\;\;\;\frac{1}{\frac{\mathsf{fma}\left(t\_0, t\_0, -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(0.16666666666666666 \cdot \left(b \cdot b\right)\right)}\\
              
              
              \end{array}
              \end{array}
              
              Derivation
              1. Split input into 4 regimes
              2. if b < -2e4

                1. Initial program 98.0%

                  \[\frac{e^{a}}{e^{a} + e^{b}} \]
                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. Applied rewrites100.0%

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

                if -2e4 < b < 4e21

                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. lower-/.f64N/A

                    \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                  4. div-invN/A

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

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

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

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

                    \[\leadsto \frac{1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                  9. lower-neg.f6498.5

                    \[\leadsto \frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{-a}}} \]
                4. Applied rewrites98.5%

                  \[\leadsto \color{blue}{\frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
                5. Taylor expanded in b around 0

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

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

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

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

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

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

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

                    \[\leadsto \frac{1}{1 + e^{\color{blue}{-1 \cdot a}}} \]
                  8. lower-exp.f64N/A

                    \[\leadsto \frac{1}{1 + \color{blue}{e^{-1 \cdot a}}} \]
                  9. neg-mul-1N/A

                    \[\leadsto \frac{1}{1 + e^{\color{blue}{\mathsf{neg}\left(a\right)}}} \]
                  10. lower-neg.f6495.9

                    \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                7. Applied rewrites95.9%

                  \[\leadsto \frac{1}{\color{blue}{1 + e^{-a}}} \]
                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 rewrites85.1%

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

                  if 4e21 < b < 1.99999999999999999e89

                  1. Initial program 92.9%

                    \[\frac{e^{a}}{e^{a} + e^{b}} \]
                  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.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 rewrites5.6%

                      \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right)}, 2\right)} \]
                    2. Step-by-step derivation
                      1. Applied rewrites79.5%

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

                      if 1.99999999999999999e89 < b

                      1. Initial program 98.1%

                        \[\frac{e^{a}}{e^{a} + e^{b}} \]
                      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 0

                          \[\leadsto \frac{1}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, \frac{1}{2}, 1\right), 2\right)} \]
                        3. Step-by-step derivation
                          1. Applied rewrites76.1%

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

                          Alternative 7: 73.0% accurate, 3.4× speedup?

                          \[\begin{array}{l} \\ \begin{array}{l} t_0 := \mathsf{fma}\left(b, b \cdot \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), b\right)\\ \mathbf{if}\;b \leq 4 \cdot 10^{+21}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\ \mathbf{elif}\;b \leq 2 \cdot 10^{+89}:\\ \;\;\;\;\frac{1}{\frac{\mathsf{fma}\left(t\_0, t\_0, -4\right)}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right), -2\right)}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b \cdot \left(0.16666666666666666 \cdot \left(b \cdot b\right)\right)}\\ \end{array} \end{array} \]
                          (FPCore (a b)
                           :precision binary64
                           (let* ((t_0 (fma b (* b (fma b 0.16666666666666666 0.5)) b)))
                             (if (<= b 4e+21)
                               (/ 1.0 (fma a (fma a (fma a -0.16666666666666666 0.5) -1.0) 2.0))
                               (if (<= b 2e+89)
                                 (/
                                  1.0
                                  (/
                                   (fma t_0 t_0 -4.0)
                                   (fma b (fma b (fma b 0.16666666666666666 0.5) 1.0) -2.0)))
                                 (/ 1.0 (* b (* 0.16666666666666666 (* b b))))))))
                          double code(double a, double b) {
                          	double t_0 = fma(b, (b * fma(b, 0.16666666666666666, 0.5)), b);
                          	double tmp;
                          	if (b <= 4e+21) {
                          		tmp = 1.0 / fma(a, fma(a, fma(a, -0.16666666666666666, 0.5), -1.0), 2.0);
                          	} else if (b <= 2e+89) {
                          		tmp = 1.0 / (fma(t_0, t_0, -4.0) / fma(b, fma(b, fma(b, 0.16666666666666666, 0.5), 1.0), -2.0));
                          	} else {
                          		tmp = 1.0 / (b * (0.16666666666666666 * (b * b)));
                          	}
                          	return tmp;
                          }
                          
                          function code(a, b)
                          	t_0 = fma(b, Float64(b * fma(b, 0.16666666666666666, 0.5)), b)
                          	tmp = 0.0
                          	if (b <= 4e+21)
                          		tmp = Float64(1.0 / fma(a, fma(a, fma(a, -0.16666666666666666, 0.5), -1.0), 2.0));
                          	elseif (b <= 2e+89)
                          		tmp = Float64(1.0 / Float64(fma(t_0, t_0, -4.0) / fma(b, fma(b, fma(b, 0.16666666666666666, 0.5), 1.0), -2.0)));
                          	else
                          		tmp = Float64(1.0 / Float64(b * Float64(0.16666666666666666 * Float64(b * b))));
                          	end
                          	return tmp
                          end
                          
                          code[a_, b_] := Block[{t$95$0 = N[(b * N[(b * N[(b * 0.16666666666666666 + 0.5), $MachinePrecision]), $MachinePrecision] + b), $MachinePrecision]}, If[LessEqual[b, 4e+21], N[(1.0 / N[(a * N[(a * N[(a * -0.16666666666666666 + 0.5), $MachinePrecision] + -1.0), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 2e+89], N[(1.0 / N[(N[(t$95$0 * t$95$0 + -4.0), $MachinePrecision] / N[(b * N[(b * N[(b * 0.16666666666666666 + 0.5), $MachinePrecision] + 1.0), $MachinePrecision] + -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(b * N[(0.16666666666666666 * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
                          
                          \begin{array}{l}
                          
                          \\
                          \begin{array}{l}
                          t_0 := \mathsf{fma}\left(b, b \cdot \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), b\right)\\
                          \mathbf{if}\;b \leq 4 \cdot 10^{+21}:\\
                          \;\;\;\;\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 2 \cdot 10^{+89}:\\
                          \;\;\;\;\frac{1}{\frac{\mathsf{fma}\left(t\_0, t\_0, -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(0.16666666666666666 \cdot \left(b \cdot b\right)\right)}\\
                          
                          
                          \end{array}
                          \end{array}
                          
                          Derivation
                          1. Split input into 3 regimes
                          2. if b < 4e21

                            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. lower-/.f64N/A

                                \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                              4. div-invN/A

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

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

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

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

                                \[\leadsto \frac{1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                              9. lower-neg.f6498.4

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

                              \[\leadsto \color{blue}{\frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
                            5. Taylor expanded in b around 0

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

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

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

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

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

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

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

                                \[\leadsto \frac{1}{1 + e^{\color{blue}{-1 \cdot a}}} \]
                              8. lower-exp.f64N/A

                                \[\leadsto \frac{1}{1 + \color{blue}{e^{-1 \cdot a}}} \]
                              9. neg-mul-1N/A

                                \[\leadsto \frac{1}{1 + e^{\color{blue}{\mathsf{neg}\left(a\right)}}} \]
                              10. lower-neg.f6475.3

                                \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                            7. Applied rewrites75.3%

                              \[\leadsto \frac{1}{\color{blue}{1 + e^{-a}}} \]
                            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 rewrites67.4%

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

                              if 4e21 < b < 1.99999999999999999e89

                              1. Initial program 92.9%

                                \[\frac{e^{a}}{e^{a} + e^{b}} \]
                              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.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 rewrites5.6%

                                  \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right)}, 2\right)} \]
                                2. Step-by-step derivation
                                  1. Applied rewrites79.5%

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

                                  if 1.99999999999999999e89 < b

                                  1. Initial program 98.1%

                                    \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                  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 0

                                      \[\leadsto \frac{1}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, \frac{1}{2}, 1\right), 2\right)} \]
                                    3. Step-by-step derivation
                                      1. Applied rewrites76.1%

                                        \[\leadsto \frac{1}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.5, 1\right), 2\right)} \]
                                      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. Add Preprocessing

                                      Alternative 8: 70.8% accurate, 8.7× speedup?

                                      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 2 \cdot 10^{+79}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(a, -0.16666666666666666, 0.5\right), -1\right), 2\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b \cdot \left(0.16666666666666666 \cdot \left(b \cdot b\right)\right)}\\ \end{array} \end{array} \]
                                      (FPCore (a b)
                                       :precision binary64
                                       (if (<= b 2e+79)
                                         (/ 1.0 (fma a (fma a (fma a -0.16666666666666666 0.5) -1.0) 2.0))
                                         (/ 1.0 (* b (* 0.16666666666666666 (* b b))))))
                                      double code(double a, double b) {
                                      	double tmp;
                                      	if (b <= 2e+79) {
                                      		tmp = 1.0 / fma(a, fma(a, fma(a, -0.16666666666666666, 0.5), -1.0), 2.0);
                                      	} else {
                                      		tmp = 1.0 / (b * (0.16666666666666666 * (b * b)));
                                      	}
                                      	return tmp;
                                      }
                                      
                                      function code(a, b)
                                      	tmp = 0.0
                                      	if (b <= 2e+79)
                                      		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(0.16666666666666666 * Float64(b * b))));
                                      	end
                                      	return tmp
                                      end
                                      
                                      code[a_, b_] := If[LessEqual[b, 2e+79], 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[(0.16666666666666666 * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
                                      
                                      \begin{array}{l}
                                      
                                      \\
                                      \begin{array}{l}
                                      \mathbf{if}\;b \leq 2 \cdot 10^{+79}:\\
                                      \;\;\;\;\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(0.16666666666666666 \cdot \left(b \cdot b\right)\right)}\\
                                      
                                      
                                      \end{array}
                                      \end{array}
                                      
                                      Derivation
                                      1. Split input into 2 regimes
                                      2. if b < 1.99999999999999993e79

                                        1. Initial program 98.0%

                                          \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                        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. lower-/.f64N/A

                                            \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                          4. div-invN/A

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

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

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

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

                                            \[\leadsto \frac{1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                          9. lower-neg.f6498.0

                                            \[\leadsto \frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{-a}}} \]
                                        4. Applied rewrites98.0%

                                          \[\leadsto \color{blue}{\frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
                                        5. Taylor expanded in b around 0

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

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

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

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

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

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

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

                                            \[\leadsto \frac{1}{1 + e^{\color{blue}{-1 \cdot a}}} \]
                                          8. lower-exp.f64N/A

                                            \[\leadsto \frac{1}{1 + \color{blue}{e^{-1 \cdot a}}} \]
                                          9. neg-mul-1N/A

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

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

                                          \[\leadsto \frac{1}{\color{blue}{1 + e^{-a}}} \]
                                        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 rewrites65.8%

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

                                          if 1.99999999999999993e79 < b

                                          1. Initial program 98.2%

                                            \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                          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 rewrites95.1%

                                              \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right)}, 2\right)} \]
                                            2. Taylor expanded in b around 0

                                              \[\leadsto \frac{1}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, \frac{1}{2}, 1\right), 2\right)} \]
                                            3. Step-by-step derivation
                                              1. Applied rewrites72.4%

                                                \[\leadsto \frac{1}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.5, 1\right), 2\right)} \]
                                              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 rewrites95.1%

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

                                              Alternative 9: 67.5% accurate, 9.5× speedup?

                                              \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 2 \cdot 10^{+79}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, 0.5, -1\right), 2\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b \cdot \left(0.16666666666666666 \cdot \left(b \cdot b\right)\right)}\\ \end{array} \end{array} \]
                                              (FPCore (a b)
                                               :precision binary64
                                               (if (<= b 2e+79)
                                                 (/ 1.0 (fma a (fma a 0.5 -1.0) 2.0))
                                                 (/ 1.0 (* b (* 0.16666666666666666 (* b b))))))
                                              double code(double a, double b) {
                                              	double tmp;
                                              	if (b <= 2e+79) {
                                              		tmp = 1.0 / fma(a, fma(a, 0.5, -1.0), 2.0);
                                              	} else {
                                              		tmp = 1.0 / (b * (0.16666666666666666 * (b * b)));
                                              	}
                                              	return tmp;
                                              }
                                              
                                              function code(a, b)
                                              	tmp = 0.0
                                              	if (b <= 2e+79)
                                              		tmp = Float64(1.0 / fma(a, fma(a, 0.5, -1.0), 2.0));
                                              	else
                                              		tmp = Float64(1.0 / Float64(b * Float64(0.16666666666666666 * Float64(b * b))));
                                              	end
                                              	return tmp
                                              end
                                              
                                              code[a_, b_] := If[LessEqual[b, 2e+79], N[(1.0 / N[(a * N[(a * 0.5 + -1.0), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(b * N[(0.16666666666666666 * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
                                              
                                              \begin{array}{l}
                                              
                                              \\
                                              \begin{array}{l}
                                              \mathbf{if}\;b \leq 2 \cdot 10^{+79}:\\
                                              \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, 0.5, -1\right), 2\right)}\\
                                              
                                              \mathbf{else}:\\
                                              \;\;\;\;\frac{1}{b \cdot \left(0.16666666666666666 \cdot \left(b \cdot b\right)\right)}\\
                                              
                                              
                                              \end{array}
                                              \end{array}
                                              
                                              Derivation
                                              1. Split input into 2 regimes
                                              2. if b < 1.99999999999999993e79

                                                1. Initial program 98.0%

                                                  \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                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. lower-/.f64N/A

                                                    \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                  4. div-invN/A

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

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

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

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

                                                    \[\leadsto \frac{1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                  9. lower-neg.f6498.0

                                                    \[\leadsto \frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{-a}}} \]
                                                4. Applied rewrites98.0%

                                                  \[\leadsto \color{blue}{\frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
                                                5. Taylor expanded in b around 0

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

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

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

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

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

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

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

                                                    \[\leadsto \frac{1}{1 + e^{\color{blue}{-1 \cdot a}}} \]
                                                  8. lower-exp.f64N/A

                                                    \[\leadsto \frac{1}{1 + \color{blue}{e^{-1 \cdot a}}} \]
                                                  9. neg-mul-1N/A

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

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

                                                  \[\leadsto \frac{1}{\color{blue}{1 + e^{-a}}} \]
                                                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 rewrites62.4%

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

                                                  if 1.99999999999999993e79 < b

                                                  1. Initial program 98.2%

                                                    \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                  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 rewrites95.1%

                                                      \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.16666666666666666, 0.5\right), 1\right)}, 2\right)} \]
                                                    2. Taylor expanded in b around 0

                                                      \[\leadsto \frac{1}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, \frac{1}{2}, 1\right), 2\right)} \]
                                                    3. Step-by-step derivation
                                                      1. Applied rewrites72.4%

                                                        \[\leadsto \frac{1}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.5, 1\right), 2\right)} \]
                                                      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 rewrites95.1%

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

                                                      Alternative 10: 64.2% accurate, 10.5× speedup?

                                                      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 5 \cdot 10^{+146}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, 0.5, -1\right), 2\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.5, 1\right), 2\right)}\\ \end{array} \end{array} \]
                                                      (FPCore (a b)
                                                       :precision binary64
                                                       (if (<= b 5e+146)
                                                         (/ 1.0 (fma a (fma a 0.5 -1.0) 2.0))
                                                         (/ 1.0 (fma b (fma b 0.5 1.0) 2.0))))
                                                      double code(double a, double b) {
                                                      	double tmp;
                                                      	if (b <= 5e+146) {
                                                      		tmp = 1.0 / fma(a, fma(a, 0.5, -1.0), 2.0);
                                                      	} else {
                                                      		tmp = 1.0 / fma(b, fma(b, 0.5, 1.0), 2.0);
                                                      	}
                                                      	return tmp;
                                                      }
                                                      
                                                      function code(a, b)
                                                      	tmp = 0.0
                                                      	if (b <= 5e+146)
                                                      		tmp = Float64(1.0 / fma(a, fma(a, 0.5, -1.0), 2.0));
                                                      	else
                                                      		tmp = Float64(1.0 / fma(b, fma(b, 0.5, 1.0), 2.0));
                                                      	end
                                                      	return tmp
                                                      end
                                                      
                                                      code[a_, b_] := If[LessEqual[b, 5e+146], 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 + 1.0), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision]]
                                                      
                                                      \begin{array}{l}
                                                      
                                                      \\
                                                      \begin{array}{l}
                                                      \mathbf{if}\;b \leq 5 \cdot 10^{+146}:\\
                                                      \;\;\;\;\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, 0.5, -1\right), 2\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 b < 4.9999999999999999e146

                                                        1. Initial program 98.1%

                                                          \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                        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. lower-/.f64N/A

                                                            \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                          4. div-invN/A

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

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

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

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

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

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

                                                          \[\leadsto \color{blue}{\frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
                                                        5. Taylor expanded in b around 0

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

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

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

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

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

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

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

                                                            \[\leadsto \frac{1}{1 + e^{\color{blue}{-1 \cdot a}}} \]
                                                          8. lower-exp.f64N/A

                                                            \[\leadsto \frac{1}{1 + \color{blue}{e^{-1 \cdot a}}} \]
                                                          9. neg-mul-1N/A

                                                            \[\leadsto \frac{1}{1 + e^{\color{blue}{\mathsf{neg}\left(a\right)}}} \]
                                                          10. lower-neg.f6469.2

                                                            \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                                                        7. Applied rewrites69.2%

                                                          \[\leadsto \frac{1}{\color{blue}{1 + e^{-a}}} \]
                                                        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 rewrites58.7%

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

                                                          if 4.9999999999999999e146 < b

                                                          1. Initial program 97.6%

                                                            \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                          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.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 rewrites95.8%

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

                                                          Alternative 11: 57.2% accurate, 10.5× speedup?

                                                          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -5 \cdot 10^{+25}:\\ \;\;\;\;b \cdot \left(\left(b \cdot b\right) \cdot 0.020833333333333332\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.5, 1\right), 2\right)}\\ \end{array} \end{array} \]
                                                          (FPCore (a b)
                                                           :precision binary64
                                                           (if (<= a -5e+25)
                                                             (* b (* (* b b) 0.020833333333333332))
                                                             (/ 1.0 (fma b (fma b 0.5 1.0) 2.0))))
                                                          double code(double a, double b) {
                                                          	double tmp;
                                                          	if (a <= -5e+25) {
                                                          		tmp = b * ((b * b) * 0.020833333333333332);
                                                          	} 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 <= -5e+25)
                                                          		tmp = Float64(b * Float64(Float64(b * b) * 0.020833333333333332));
                                                          	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, -5e+25], N[(b * N[(N[(b * b), $MachinePrecision] * 0.020833333333333332), $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 -5 \cdot 10^{+25}:\\
                                                          \;\;\;\;b \cdot \left(\left(b \cdot b\right) \cdot 0.020833333333333332\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 < -5.00000000000000024e25

                                                            1. Initial program 98.3%

                                                              \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                            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.f6436.0

                                                                \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                                            5. Applied rewrites36.0%

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

                                                              \[\leadsto \frac{1}{2} + \color{blue}{b \cdot \left(\frac{1}{48} \cdot {b}^{2} - \frac{1}{4}\right)} \]
                                                            7. Step-by-step derivation
                                                              1. Applied rewrites2.7%

                                                                \[\leadsto \mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, b \cdot 0.020833333333333332, -0.25\right)}, 0.5\right) \]
                                                              2. Taylor expanded in b around 0

                                                                \[\leadsto \mathsf{fma}\left(b, \frac{-1}{4}, \frac{1}{2}\right) \]
                                                              3. Step-by-step derivation
                                                                1. Applied rewrites2.8%

                                                                  \[\leadsto \mathsf{fma}\left(b, -0.25, 0.5\right) \]
                                                                2. Taylor expanded in b around inf

                                                                  \[\leadsto \frac{1}{48} \cdot {b}^{\color{blue}{3}} \]
                                                                3. Step-by-step derivation
                                                                  1. Applied rewrites42.7%

                                                                    \[\leadsto b \cdot \left(0.020833333333333332 \cdot \color{blue}{\left(b \cdot b\right)}\right) \]

                                                                  if -5.00000000000000024e25 < a

                                                                  1. Initial program 97.9%

                                                                    \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                  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.f6498.7

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

                                                                    \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                  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 rewrites61.7%

                                                                      \[\leadsto \frac{1}{\mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, 0.5, 1\right)}, 2\right)} \]
                                                                  8. Recombined 2 regimes into one program.
                                                                  9. Final simplification57.3%

                                                                    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -5 \cdot 10^{+25}:\\ \;\;\;\;b \cdot \left(\left(b \cdot b\right) \cdot 0.020833333333333332\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(b, \mathsf{fma}\left(b, 0.5, 1\right), 2\right)}\\ \end{array} \]
                                                                  10. Add Preprocessing

                                                                  Alternative 12: 51.3% accurate, 11.7× speedup?

                                                                  \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -5 \cdot 10^{+25}:\\ \;\;\;\;b \cdot \left(\left(b \cdot b\right) \cdot 0.020833333333333332\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{a + 1}{1 + \left(a + 1\right)}\\ \end{array} \end{array} \]
                                                                  (FPCore (a b)
                                                                   :precision binary64
                                                                   (if (<= a -5e+25)
                                                                     (* b (* (* b b) 0.020833333333333332))
                                                                     (/ (+ a 1.0) (+ 1.0 (+ a 1.0)))))
                                                                  double code(double a, double b) {
                                                                  	double tmp;
                                                                  	if (a <= -5e+25) {
                                                                  		tmp = b * ((b * b) * 0.020833333333333332);
                                                                  	} else {
                                                                  		tmp = (a + 1.0) / (1.0 + (a + 1.0));
                                                                  	}
                                                                  	return tmp;
                                                                  }
                                                                  
                                                                  real(8) function code(a, b)
                                                                      real(8), intent (in) :: a
                                                                      real(8), intent (in) :: b
                                                                      real(8) :: tmp
                                                                      if (a <= (-5d+25)) then
                                                                          tmp = b * ((b * b) * 0.020833333333333332d0)
                                                                      else
                                                                          tmp = (a + 1.0d0) / (1.0d0 + (a + 1.0d0))
                                                                      end if
                                                                      code = tmp
                                                                  end function
                                                                  
                                                                  public static double code(double a, double b) {
                                                                  	double tmp;
                                                                  	if (a <= -5e+25) {
                                                                  		tmp = b * ((b * b) * 0.020833333333333332);
                                                                  	} else {
                                                                  		tmp = (a + 1.0) / (1.0 + (a + 1.0));
                                                                  	}
                                                                  	return tmp;
                                                                  }
                                                                  
                                                                  def code(a, b):
                                                                  	tmp = 0
                                                                  	if a <= -5e+25:
                                                                  		tmp = b * ((b * b) * 0.020833333333333332)
                                                                  	else:
                                                                  		tmp = (a + 1.0) / (1.0 + (a + 1.0))
                                                                  	return tmp
                                                                  
                                                                  function code(a, b)
                                                                  	tmp = 0.0
                                                                  	if (a <= -5e+25)
                                                                  		tmp = Float64(b * Float64(Float64(b * b) * 0.020833333333333332));
                                                                  	else
                                                                  		tmp = Float64(Float64(a + 1.0) / Float64(1.0 + Float64(a + 1.0)));
                                                                  	end
                                                                  	return tmp
                                                                  end
                                                                  
                                                                  function tmp_2 = code(a, b)
                                                                  	tmp = 0.0;
                                                                  	if (a <= -5e+25)
                                                                  		tmp = b * ((b * b) * 0.020833333333333332);
                                                                  	else
                                                                  		tmp = (a + 1.0) / (1.0 + (a + 1.0));
                                                                  	end
                                                                  	tmp_2 = tmp;
                                                                  end
                                                                  
                                                                  code[a_, b_] := If[LessEqual[a, -5e+25], N[(b * N[(N[(b * b), $MachinePrecision] * 0.020833333333333332), $MachinePrecision]), $MachinePrecision], N[(N[(a + 1.0), $MachinePrecision] / N[(1.0 + N[(a + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
                                                                  
                                                                  \begin{array}{l}
                                                                  
                                                                  \\
                                                                  \begin{array}{l}
                                                                  \mathbf{if}\;a \leq -5 \cdot 10^{+25}:\\
                                                                  \;\;\;\;b \cdot \left(\left(b \cdot b\right) \cdot 0.020833333333333332\right)\\
                                                                  
                                                                  \mathbf{else}:\\
                                                                  \;\;\;\;\frac{a + 1}{1 + \left(a + 1\right)}\\
                                                                  
                                                                  
                                                                  \end{array}
                                                                  \end{array}
                                                                  
                                                                  Derivation
                                                                  1. Split input into 2 regimes
                                                                  2. if a < -5.00000000000000024e25

                                                                    1. Initial program 98.3%

                                                                      \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                    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.f6436.0

                                                                        \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                                                    5. Applied rewrites36.0%

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

                                                                      \[\leadsto \frac{1}{2} + \color{blue}{b \cdot \left(\frac{1}{48} \cdot {b}^{2} - \frac{1}{4}\right)} \]
                                                                    7. Step-by-step derivation
                                                                      1. Applied rewrites2.7%

                                                                        \[\leadsto \mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, b \cdot 0.020833333333333332, -0.25\right)}, 0.5\right) \]
                                                                      2. Taylor expanded in b around 0

                                                                        \[\leadsto \mathsf{fma}\left(b, \frac{-1}{4}, \frac{1}{2}\right) \]
                                                                      3. Step-by-step derivation
                                                                        1. Applied rewrites2.8%

                                                                          \[\leadsto \mathsf{fma}\left(b, -0.25, 0.5\right) \]
                                                                        2. Taylor expanded in b around inf

                                                                          \[\leadsto \frac{1}{48} \cdot {b}^{\color{blue}{3}} \]
                                                                        3. Step-by-step derivation
                                                                          1. Applied rewrites42.7%

                                                                            \[\leadsto b \cdot \left(0.020833333333333332 \cdot \color{blue}{\left(b \cdot b\right)}\right) \]

                                                                          if -5.00000000000000024e25 < a

                                                                          1. Initial program 97.9%

                                                                            \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                          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 rewrites51.3%

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

                                                                              \[\leadsto \frac{e^{a}}{\color{blue}{\left(1 + a\right)} + 1} \]
                                                                            3. Step-by-step derivation
                                                                              1. lower-+.f6450.7

                                                                                \[\leadsto \frac{e^{a}}{\color{blue}{\left(1 + a\right)} + 1} \]
                                                                            4. Applied rewrites50.7%

                                                                              \[\leadsto \frac{e^{a}}{\color{blue}{\left(1 + a\right)} + 1} \]
                                                                            5. Taylor expanded in a around 0

                                                                              \[\leadsto \frac{\color{blue}{1 + a}}{\left(1 + a\right) + 1} \]
                                                                            6. Step-by-step derivation
                                                                              1. lower-+.f6450.7

                                                                                \[\leadsto \frac{\color{blue}{1 + a}}{\left(1 + a\right) + 1} \]
                                                                            7. Applied rewrites50.7%

                                                                              \[\leadsto \frac{\color{blue}{1 + a}}{\left(1 + a\right) + 1} \]
                                                                          5. Recombined 2 regimes into one program.
                                                                          6. Final simplification48.9%

                                                                            \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -5 \cdot 10^{+25}:\\ \;\;\;\;b \cdot \left(\left(b \cdot b\right) \cdot 0.020833333333333332\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{a + 1}{1 + \left(a + 1\right)}\\ \end{array} \]
                                                                          7. Add Preprocessing

                                                                          Alternative 13: 50.9% accurate, 13.1× speedup?

                                                                          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -5 \cdot 10^{+25}:\\ \;\;\;\;b \cdot \left(\left(b \cdot b\right) \cdot 0.020833333333333332\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{1 + \left(1 - a\right)}\\ \end{array} \end{array} \]
                                                                          (FPCore (a b)
                                                                           :precision binary64
                                                                           (if (<= a -5e+25)
                                                                             (* b (* (* b b) 0.020833333333333332))
                                                                             (/ 1.0 (+ 1.0 (- 1.0 a)))))
                                                                          double code(double a, double b) {
                                                                          	double tmp;
                                                                          	if (a <= -5e+25) {
                                                                          		tmp = b * ((b * b) * 0.020833333333333332);
                                                                          	} else {
                                                                          		tmp = 1.0 / (1.0 + (1.0 - a));
                                                                          	}
                                                                          	return tmp;
                                                                          }
                                                                          
                                                                          real(8) function code(a, b)
                                                                              real(8), intent (in) :: a
                                                                              real(8), intent (in) :: b
                                                                              real(8) :: tmp
                                                                              if (a <= (-5d+25)) then
                                                                                  tmp = b * ((b * b) * 0.020833333333333332d0)
                                                                              else
                                                                                  tmp = 1.0d0 / (1.0d0 + (1.0d0 - a))
                                                                              end if
                                                                              code = tmp
                                                                          end function
                                                                          
                                                                          public static double code(double a, double b) {
                                                                          	double tmp;
                                                                          	if (a <= -5e+25) {
                                                                          		tmp = b * ((b * b) * 0.020833333333333332);
                                                                          	} else {
                                                                          		tmp = 1.0 / (1.0 + (1.0 - a));
                                                                          	}
                                                                          	return tmp;
                                                                          }
                                                                          
                                                                          def code(a, b):
                                                                          	tmp = 0
                                                                          	if a <= -5e+25:
                                                                          		tmp = b * ((b * b) * 0.020833333333333332)
                                                                          	else:
                                                                          		tmp = 1.0 / (1.0 + (1.0 - a))
                                                                          	return tmp
                                                                          
                                                                          function code(a, b)
                                                                          	tmp = 0.0
                                                                          	if (a <= -5e+25)
                                                                          		tmp = Float64(b * Float64(Float64(b * b) * 0.020833333333333332));
                                                                          	else
                                                                          		tmp = Float64(1.0 / Float64(1.0 + Float64(1.0 - a)));
                                                                          	end
                                                                          	return tmp
                                                                          end
                                                                          
                                                                          function tmp_2 = code(a, b)
                                                                          	tmp = 0.0;
                                                                          	if (a <= -5e+25)
                                                                          		tmp = b * ((b * b) * 0.020833333333333332);
                                                                          	else
                                                                          		tmp = 1.0 / (1.0 + (1.0 - a));
                                                                          	end
                                                                          	tmp_2 = tmp;
                                                                          end
                                                                          
                                                                          code[a_, b_] := If[LessEqual[a, -5e+25], N[(b * N[(N[(b * b), $MachinePrecision] * 0.020833333333333332), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(1.0 + N[(1.0 - a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
                                                                          
                                                                          \begin{array}{l}
                                                                          
                                                                          \\
                                                                          \begin{array}{l}
                                                                          \mathbf{if}\;a \leq -5 \cdot 10^{+25}:\\
                                                                          \;\;\;\;b \cdot \left(\left(b \cdot b\right) \cdot 0.020833333333333332\right)\\
                                                                          
                                                                          \mathbf{else}:\\
                                                                          \;\;\;\;\frac{1}{1 + \left(1 - a\right)}\\
                                                                          
                                                                          
                                                                          \end{array}
                                                                          \end{array}
                                                                          
                                                                          Derivation
                                                                          1. Split input into 2 regimes
                                                                          2. if a < -5.00000000000000024e25

                                                                            1. Initial program 98.3%

                                                                              \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                            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.f6436.0

                                                                                \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                                                            5. Applied rewrites36.0%

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

                                                                              \[\leadsto \frac{1}{2} + \color{blue}{b \cdot \left(\frac{1}{48} \cdot {b}^{2} - \frac{1}{4}\right)} \]
                                                                            7. Step-by-step derivation
                                                                              1. Applied rewrites2.7%

                                                                                \[\leadsto \mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, b \cdot 0.020833333333333332, -0.25\right)}, 0.5\right) \]
                                                                              2. Taylor expanded in b around 0

                                                                                \[\leadsto \mathsf{fma}\left(b, \frac{-1}{4}, \frac{1}{2}\right) \]
                                                                              3. Step-by-step derivation
                                                                                1. Applied rewrites2.8%

                                                                                  \[\leadsto \mathsf{fma}\left(b, -0.25, 0.5\right) \]
                                                                                2. Taylor expanded in b around inf

                                                                                  \[\leadsto \frac{1}{48} \cdot {b}^{\color{blue}{3}} \]
                                                                                3. Step-by-step derivation
                                                                                  1. Applied rewrites42.7%

                                                                                    \[\leadsto b \cdot \left(0.020833333333333332 \cdot \color{blue}{\left(b \cdot b\right)}\right) \]

                                                                                  if -5.00000000000000024e25 < a

                                                                                  1. Initial program 97.9%

                                                                                    \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                  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. lower-/.f64N/A

                                                                                      \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                                                    4. div-invN/A

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

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

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

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

                                                                                      \[\leadsto \frac{1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                    9. lower-neg.f6497.9

                                                                                      \[\leadsto \frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{-a}}} \]
                                                                                  4. Applied rewrites97.9%

                                                                                    \[\leadsto \color{blue}{\frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
                                                                                  5. Taylor expanded in b around 0

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

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

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

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

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

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

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

                                                                                      \[\leadsto \frac{1}{1 + e^{\color{blue}{-1 \cdot a}}} \]
                                                                                    8. lower-exp.f64N/A

                                                                                      \[\leadsto \frac{1}{1 + \color{blue}{e^{-1 \cdot a}}} \]
                                                                                    9. neg-mul-1N/A

                                                                                      \[\leadsto \frac{1}{1 + e^{\color{blue}{\mathsf{neg}\left(a\right)}}} \]
                                                                                    10. lower-neg.f6451.8

                                                                                      \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                                                                                  7. Applied rewrites51.8%

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

                                                                                    \[\leadsto \frac{1}{1 + \left(1 + \color{blue}{-1 \cdot a}\right)} \]
                                                                                  9. Step-by-step derivation
                                                                                    1. Applied rewrites50.3%

                                                                                      \[\leadsto \frac{1}{1 + \left(1 - \color{blue}{a}\right)} \]
                                                                                  10. Recombined 2 regimes into one program.
                                                                                  11. Final simplification48.5%

                                                                                    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -5 \cdot 10^{+25}:\\ \;\;\;\;b \cdot \left(\left(b \cdot b\right) \cdot 0.020833333333333332\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{1 + \left(1 - a\right)}\\ \end{array} \]
                                                                                  12. Add Preprocessing

                                                                                  Alternative 14: 50.9% accurate, 14.3× speedup?

                                                                                  \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -5 \cdot 10^{+25}:\\ \;\;\;\;b \cdot \left(\left(b \cdot b\right) \cdot 0.020833333333333332\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 - a}\\ \end{array} \end{array} \]
                                                                                  (FPCore (a b)
                                                                                   :precision binary64
                                                                                   (if (<= a -5e+25) (* b (* (* b b) 0.020833333333333332)) (/ 1.0 (- 2.0 a))))
                                                                                  double code(double a, double b) {
                                                                                  	double tmp;
                                                                                  	if (a <= -5e+25) {
                                                                                  		tmp = b * ((b * b) * 0.020833333333333332);
                                                                                  	} else {
                                                                                  		tmp = 1.0 / (2.0 - a);
                                                                                  	}
                                                                                  	return tmp;
                                                                                  }
                                                                                  
                                                                                  real(8) function code(a, b)
                                                                                      real(8), intent (in) :: a
                                                                                      real(8), intent (in) :: b
                                                                                      real(8) :: tmp
                                                                                      if (a <= (-5d+25)) then
                                                                                          tmp = b * ((b * b) * 0.020833333333333332d0)
                                                                                      else
                                                                                          tmp = 1.0d0 / (2.0d0 - a)
                                                                                      end if
                                                                                      code = tmp
                                                                                  end function
                                                                                  
                                                                                  public static double code(double a, double b) {
                                                                                  	double tmp;
                                                                                  	if (a <= -5e+25) {
                                                                                  		tmp = b * ((b * b) * 0.020833333333333332);
                                                                                  	} else {
                                                                                  		tmp = 1.0 / (2.0 - a);
                                                                                  	}
                                                                                  	return tmp;
                                                                                  }
                                                                                  
                                                                                  def code(a, b):
                                                                                  	tmp = 0
                                                                                  	if a <= -5e+25:
                                                                                  		tmp = b * ((b * b) * 0.020833333333333332)
                                                                                  	else:
                                                                                  		tmp = 1.0 / (2.0 - a)
                                                                                  	return tmp
                                                                                  
                                                                                  function code(a, b)
                                                                                  	tmp = 0.0
                                                                                  	if (a <= -5e+25)
                                                                                  		tmp = Float64(b * Float64(Float64(b * b) * 0.020833333333333332));
                                                                                  	else
                                                                                  		tmp = Float64(1.0 / Float64(2.0 - a));
                                                                                  	end
                                                                                  	return tmp
                                                                                  end
                                                                                  
                                                                                  function tmp_2 = code(a, b)
                                                                                  	tmp = 0.0;
                                                                                  	if (a <= -5e+25)
                                                                                  		tmp = b * ((b * b) * 0.020833333333333332);
                                                                                  	else
                                                                                  		tmp = 1.0 / (2.0 - a);
                                                                                  	end
                                                                                  	tmp_2 = tmp;
                                                                                  end
                                                                                  
                                                                                  code[a_, b_] := If[LessEqual[a, -5e+25], N[(b * N[(N[(b * b), $MachinePrecision] * 0.020833333333333332), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(2.0 - a), $MachinePrecision]), $MachinePrecision]]
                                                                                  
                                                                                  \begin{array}{l}
                                                                                  
                                                                                  \\
                                                                                  \begin{array}{l}
                                                                                  \mathbf{if}\;a \leq -5 \cdot 10^{+25}:\\
                                                                                  \;\;\;\;b \cdot \left(\left(b \cdot b\right) \cdot 0.020833333333333332\right)\\
                                                                                  
                                                                                  \mathbf{else}:\\
                                                                                  \;\;\;\;\frac{1}{2 - a}\\
                                                                                  
                                                                                  
                                                                                  \end{array}
                                                                                  \end{array}
                                                                                  
                                                                                  Derivation
                                                                                  1. Split input into 2 regimes
                                                                                  2. if a < -5.00000000000000024e25

                                                                                    1. Initial program 98.3%

                                                                                      \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                    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.f6436.0

                                                                                        \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                                                                    5. Applied rewrites36.0%

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

                                                                                      \[\leadsto \frac{1}{2} + \color{blue}{b \cdot \left(\frac{1}{48} \cdot {b}^{2} - \frac{1}{4}\right)} \]
                                                                                    7. Step-by-step derivation
                                                                                      1. Applied rewrites2.7%

                                                                                        \[\leadsto \mathsf{fma}\left(b, \color{blue}{\mathsf{fma}\left(b, b \cdot 0.020833333333333332, -0.25\right)}, 0.5\right) \]
                                                                                      2. Taylor expanded in b around 0

                                                                                        \[\leadsto \mathsf{fma}\left(b, \frac{-1}{4}, \frac{1}{2}\right) \]
                                                                                      3. Step-by-step derivation
                                                                                        1. Applied rewrites2.8%

                                                                                          \[\leadsto \mathsf{fma}\left(b, -0.25, 0.5\right) \]
                                                                                        2. Taylor expanded in b around inf

                                                                                          \[\leadsto \frac{1}{48} \cdot {b}^{\color{blue}{3}} \]
                                                                                        3. Step-by-step derivation
                                                                                          1. Applied rewrites42.7%

                                                                                            \[\leadsto b \cdot \left(0.020833333333333332 \cdot \color{blue}{\left(b \cdot b\right)}\right) \]

                                                                                          if -5.00000000000000024e25 < a

                                                                                          1. Initial program 97.9%

                                                                                            \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                          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. lower-/.f64N/A

                                                                                              \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                                                            4. div-invN/A

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

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

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

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

                                                                                              \[\leadsto \frac{1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                            9. lower-neg.f6497.9

                                                                                              \[\leadsto \frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{-a}}} \]
                                                                                          4. Applied rewrites97.9%

                                                                                            \[\leadsto \color{blue}{\frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
                                                                                          5. Taylor expanded in b around 0

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

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

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

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

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

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

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

                                                                                              \[\leadsto \frac{1}{1 + e^{\color{blue}{-1 \cdot a}}} \]
                                                                                            8. lower-exp.f64N/A

                                                                                              \[\leadsto \frac{1}{1 + \color{blue}{e^{-1 \cdot a}}} \]
                                                                                            9. neg-mul-1N/A

                                                                                              \[\leadsto \frac{1}{1 + e^{\color{blue}{\mathsf{neg}\left(a\right)}}} \]
                                                                                            10. lower-neg.f6451.8

                                                                                              \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                                                                                          7. Applied rewrites51.8%

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

                                                                                            \[\leadsto \frac{1}{2 + \color{blue}{-1 \cdot a}} \]
                                                                                          9. Step-by-step derivation
                                                                                            1. Applied rewrites50.3%

                                                                                              \[\leadsto \frac{1}{2 - \color{blue}{a}} \]
                                                                                          10. Recombined 2 regimes into one program.
                                                                                          11. Final simplification48.5%

                                                                                            \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -5 \cdot 10^{+25}:\\ \;\;\;\;b \cdot \left(\left(b \cdot b\right) \cdot 0.020833333333333332\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 - a}\\ \end{array} \]
                                                                                          12. Add Preprocessing

                                                                                          Alternative 15: 40.6% 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 98.0%

                                                                                            \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                          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. lower-/.f64N/A

                                                                                              \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                                                            4. div-invN/A

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

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

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

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

                                                                                              \[\leadsto \frac{1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{\mathsf{neg}\left(a\right)}}} \]
                                                                                            9. lower-neg.f6498.0

                                                                                              \[\leadsto \frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{\color{blue}{-a}}} \]
                                                                                          4. Applied rewrites98.0%

                                                                                            \[\leadsto \color{blue}{\frac{1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
                                                                                          5. Taylor expanded in b around 0

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

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

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

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

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

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

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

                                                                                              \[\leadsto \frac{1}{1 + e^{\color{blue}{-1 \cdot a}}} \]
                                                                                            8. lower-exp.f64N/A

                                                                                              \[\leadsto \frac{1}{1 + \color{blue}{e^{-1 \cdot a}}} \]
                                                                                            9. neg-mul-1N/A

                                                                                              \[\leadsto \frac{1}{1 + e^{\color{blue}{\mathsf{neg}\left(a\right)}}} \]
                                                                                            10. lower-neg.f6462.9

                                                                                              \[\leadsto \frac{1}{1 + e^{\color{blue}{-a}}} \]
                                                                                          7. Applied rewrites62.9%

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

                                                                                            \[\leadsto \frac{1}{2 + \color{blue}{-1 \cdot a}} \]
                                                                                          9. Step-by-step derivation
                                                                                            1. Applied rewrites39.9%

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

                                                                                            Alternative 16: 39.7% 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 98.0%

                                                                                              \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                                            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.f6484.2

                                                                                                \[\leadsto \frac{1}{1 + \color{blue}{e^{b}}} \]
                                                                                            5. Applied rewrites84.2%

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

                                                                                              \[\leadsto \frac{1}{2} \]
                                                                                            7. Step-by-step derivation
                                                                                              1. Applied rewrites39.3%

                                                                                                \[\leadsto 0.5 \]
                                                                                              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 2024214 
                                                                                              (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))))