Quotient of sum of exps

Percentage Accurate: 98.9% → 98.3%
Time: 6.1s
Alternatives: 14
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 14 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, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{a} \leq 0.995:\\ \;\;\;\;\frac{e^{a}}{e^{a} + 1}\\ \mathbf{else}:\\ \;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= (exp a) 0.995)
   (/ (exp a) (+ (exp a) 1.0))
   (pow (+ (exp b) 1.0) -1.0)))
double code(double a, double b) {
	double tmp;
	if (exp(a) <= 0.995) {
		tmp = exp(a) / (exp(a) + 1.0);
	} else {
		tmp = pow((exp(b) + 1.0), -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) <= 0.995d0) then
        tmp = exp(a) / (exp(a) + 1.0d0)
    else
        tmp = (exp(b) + 1.0d0) ** (-1.0d0)
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (Math.exp(a) <= 0.995) {
		tmp = Math.exp(a) / (Math.exp(a) + 1.0);
	} else {
		tmp = Math.pow((Math.exp(b) + 1.0), -1.0);
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if math.exp(a) <= 0.995:
		tmp = math.exp(a) / (math.exp(a) + 1.0)
	else:
		tmp = math.pow((math.exp(b) + 1.0), -1.0)
	return tmp
function code(a, b)
	tmp = 0.0
	if (exp(a) <= 0.995)
		tmp = Float64(exp(a) / Float64(exp(a) + 1.0));
	else
		tmp = Float64(exp(b) + 1.0) ^ -1.0;
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (exp(a) <= 0.995)
		tmp = exp(a) / (exp(a) + 1.0);
	else
		tmp = (exp(b) + 1.0) ^ -1.0;
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[N[Exp[a], $MachinePrecision], 0.995], N[(N[Exp[a], $MachinePrecision] / N[(N[Exp[a], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision], N[Power[N[(N[Exp[b], $MachinePrecision] + 1.0), $MachinePrecision], -1.0], $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;e^{a} \leq 0.995:\\
\;\;\;\;\frac{e^{a}}{e^{a} + 1}\\

\mathbf{else}:\\
\;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (exp.f64 a) < 0.994999999999999996

    1. Initial program 98.7%

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

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

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

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

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

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

    if 0.994999999999999996 < (exp.f64 a)

    1. Initial program 98.9%

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

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

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

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

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

        \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
    5. Applied rewrites98.3%

      \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;e^{a} \leq 0.995:\\ \;\;\;\;\frac{e^{a}}{e^{a} + 1}\\ \mathbf{else}:\\ \;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 98.9% accurate, 1.0× speedup?

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

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

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

Alternative 3: 98.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{a} \leq 0.995:\\ \;\;\;\;{\left(1 + e^{-a}\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= (exp a) 0.995)
   (pow (+ 1.0 (exp (- a))) -1.0)
   (pow (+ (exp b) 1.0) -1.0)))
double code(double a, double b) {
	double tmp;
	if (exp(a) <= 0.995) {
		tmp = pow((1.0 + exp(-a)), -1.0);
	} else {
		tmp = pow((exp(b) + 1.0), -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) <= 0.995d0) then
        tmp = (1.0d0 + exp(-a)) ** (-1.0d0)
    else
        tmp = (exp(b) + 1.0d0) ** (-1.0d0)
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (Math.exp(a) <= 0.995) {
		tmp = Math.pow((1.0 + Math.exp(-a)), -1.0);
	} else {
		tmp = Math.pow((Math.exp(b) + 1.0), -1.0);
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if math.exp(a) <= 0.995:
		tmp = math.pow((1.0 + math.exp(-a)), -1.0)
	else:
		tmp = math.pow((math.exp(b) + 1.0), -1.0)
	return tmp
function code(a, b)
	tmp = 0.0
	if (exp(a) <= 0.995)
		tmp = Float64(1.0 + exp(Float64(-a))) ^ -1.0;
	else
		tmp = Float64(exp(b) + 1.0) ^ -1.0;
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (exp(a) <= 0.995)
		tmp = (1.0 + exp(-a)) ^ -1.0;
	else
		tmp = (exp(b) + 1.0) ^ -1.0;
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[N[Exp[a], $MachinePrecision], 0.995], N[Power[N[(1.0 + N[Exp[(-a)], $MachinePrecision]), $MachinePrecision], -1.0], $MachinePrecision], N[Power[N[(N[Exp[b], $MachinePrecision] + 1.0), $MachinePrecision], -1.0], $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;e^{a} \leq 0.995:\\
\;\;\;\;{\left(1 + e^{-a}\right)}^{-1}\\

\mathbf{else}:\\
\;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (exp.f64 a) < 0.994999999999999996

    1. Initial program 98.7%

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto {\left({\left(\frac{\color{blue}{e^{b} + e^{a}}}{e^{a}}\right)}^{\left(\frac{-1}{2}\right)}\right)}^{2} \]
      12. metadata-eval98.6

        \[\leadsto {\left({\left(\frac{e^{b} + e^{a}}{e^{a}}\right)}^{\color{blue}{-0.5}}\right)}^{2} \]
    4. Applied rewrites98.6%

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

      \[\leadsto {\left({\color{blue}{\left(\frac{1 + e^{a}}{e^{a}}\right)}}^{\frac{-1}{2}}\right)}^{2} \]
    6. Step-by-step derivation
      1. *-lft-identityN/A

        \[\leadsto {\left({\left(\frac{\color{blue}{1 \cdot \left(1 + e^{a}\right)}}{e^{a}}\right)}^{\frac{-1}{2}}\right)}^{2} \]
      2. associate-*l/N/A

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

        \[\leadsto {\left({\color{blue}{\left(\frac{1}{e^{a}} \cdot 1 + \frac{1}{e^{a}} \cdot e^{a}\right)}}^{\frac{-1}{2}}\right)}^{2} \]
      4. *-rgt-identityN/A

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

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

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

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

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

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

        \[\leadsto {\left({\left(e^{\color{blue}{\mathsf{neg}\left(a\right)}} + 1\right)}^{\frac{-1}{2}}\right)}^{2} \]
      11. lower-neg.f64100.0

        \[\leadsto {\left({\left(e^{\color{blue}{-a}} + 1\right)}^{-0.5}\right)}^{2} \]
    7. Applied rewrites100.0%

      \[\leadsto {\left({\color{blue}{\left(e^{-a} + 1\right)}}^{-0.5}\right)}^{2} \]
    8. Step-by-step derivation
      1. lift-pow.f64N/A

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

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

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

        \[\leadsto {\left(e^{-a} + 1\right)}^{\color{blue}{-1}} \]
      5. unpow-1N/A

        \[\leadsto \color{blue}{\frac{1}{e^{-a} + 1}} \]
      6. lower-/.f64100.0

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

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

    if 0.994999999999999996 < (exp.f64 a)

    1. Initial program 98.9%

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

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

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

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

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

        \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
    5. Applied rewrites98.3%

      \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;e^{a} \leq 0.995:\\ \;\;\;\;{\left(1 + e^{-a}\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 98.2% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{a} \leq 0.995:\\ \;\;\;\;\frac{e^{a}}{2 + a}\\ \mathbf{else}:\\ \;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= (exp a) 0.995) (/ (exp a) (+ 2.0 a)) (pow (+ (exp b) 1.0) -1.0)))
double code(double a, double b) {
	double tmp;
	if (exp(a) <= 0.995) {
		tmp = exp(a) / (2.0 + a);
	} else {
		tmp = pow((exp(b) + 1.0), -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) <= 0.995d0) then
        tmp = exp(a) / (2.0d0 + a)
    else
        tmp = (exp(b) + 1.0d0) ** (-1.0d0)
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (Math.exp(a) <= 0.995) {
		tmp = Math.exp(a) / (2.0 + a);
	} else {
		tmp = Math.pow((Math.exp(b) + 1.0), -1.0);
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if math.exp(a) <= 0.995:
		tmp = math.exp(a) / (2.0 + a)
	else:
		tmp = math.pow((math.exp(b) + 1.0), -1.0)
	return tmp
function code(a, b)
	tmp = 0.0
	if (exp(a) <= 0.995)
		tmp = Float64(exp(a) / Float64(2.0 + a));
	else
		tmp = Float64(exp(b) + 1.0) ^ -1.0;
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (exp(a) <= 0.995)
		tmp = exp(a) / (2.0 + a);
	else
		tmp = (exp(b) + 1.0) ^ -1.0;
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[N[Exp[a], $MachinePrecision], 0.995], N[(N[Exp[a], $MachinePrecision] / N[(2.0 + a), $MachinePrecision]), $MachinePrecision], N[Power[N[(N[Exp[b], $MachinePrecision] + 1.0), $MachinePrecision], -1.0], $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;e^{a} \leq 0.995:\\
\;\;\;\;\frac{e^{a}}{2 + a}\\

\mathbf{else}:\\
\;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (exp.f64 a) < 0.994999999999999996

    1. Initial program 98.7%

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

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

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

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

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

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

      \[\leadsto \frac{e^{a}}{2 + \color{blue}{a}} \]
    7. Step-by-step derivation
      1. Applied rewrites98.3%

        \[\leadsto \frac{e^{a}}{2 + \color{blue}{a}} \]

      if 0.994999999999999996 < (exp.f64 a)

      1. Initial program 98.9%

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

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

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

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

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

          \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
      5. Applied rewrites98.3%

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

      \[\leadsto \begin{array}{l} \mathbf{if}\;e^{a} \leq 0.995:\\ \;\;\;\;\frac{e^{a}}{2 + a}\\ \mathbf{else}:\\ \;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\ \end{array} \]
    10. Add Preprocessing

    Alternative 5: 98.2% accurate, 1.0× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{a} \leq 0.995:\\ \;\;\;\;\frac{e^{a}}{2}\\ \mathbf{else}:\\ \;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\ \end{array} \end{array} \]
    (FPCore (a b)
     :precision binary64
     (if (<= (exp a) 0.995) (/ (exp a) 2.0) (pow (+ (exp b) 1.0) -1.0)))
    double code(double a, double b) {
    	double tmp;
    	if (exp(a) <= 0.995) {
    		tmp = exp(a) / 2.0;
    	} else {
    		tmp = pow((exp(b) + 1.0), -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) <= 0.995d0) then
            tmp = exp(a) / 2.0d0
        else
            tmp = (exp(b) + 1.0d0) ** (-1.0d0)
        end if
        code = tmp
    end function
    
    public static double code(double a, double b) {
    	double tmp;
    	if (Math.exp(a) <= 0.995) {
    		tmp = Math.exp(a) / 2.0;
    	} else {
    		tmp = Math.pow((Math.exp(b) + 1.0), -1.0);
    	}
    	return tmp;
    }
    
    def code(a, b):
    	tmp = 0
    	if math.exp(a) <= 0.995:
    		tmp = math.exp(a) / 2.0
    	else:
    		tmp = math.pow((math.exp(b) + 1.0), -1.0)
    	return tmp
    
    function code(a, b)
    	tmp = 0.0
    	if (exp(a) <= 0.995)
    		tmp = Float64(exp(a) / 2.0);
    	else
    		tmp = Float64(exp(b) + 1.0) ^ -1.0;
    	end
    	return tmp
    end
    
    function tmp_2 = code(a, b)
    	tmp = 0.0;
    	if (exp(a) <= 0.995)
    		tmp = exp(a) / 2.0;
    	else
    		tmp = (exp(b) + 1.0) ^ -1.0;
    	end
    	tmp_2 = tmp;
    end
    
    code[a_, b_] := If[LessEqual[N[Exp[a], $MachinePrecision], 0.995], N[(N[Exp[a], $MachinePrecision] / 2.0), $MachinePrecision], N[Power[N[(N[Exp[b], $MachinePrecision] + 1.0), $MachinePrecision], -1.0], $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;e^{a} \leq 0.995:\\
    \;\;\;\;\frac{e^{a}}{2}\\
    
    \mathbf{else}:\\
    \;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (exp.f64 a) < 0.994999999999999996

      1. Initial program 98.7%

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

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

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

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

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

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

        \[\leadsto \frac{e^{a}}{2} \]
      7. Step-by-step derivation
        1. Applied rewrites98.0%

          \[\leadsto \frac{e^{a}}{2} \]

        if 0.994999999999999996 < (exp.f64 a)

        1. Initial program 98.9%

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

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

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

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

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

            \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
        5. Applied rewrites98.3%

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

        \[\leadsto \begin{array}{l} \mathbf{if}\;e^{a} \leq 0.995:\\ \;\;\;\;\frac{e^{a}}{2}\\ \mathbf{else}:\\ \;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\ \end{array} \]
      10. Add Preprocessing

      Alternative 6: 53.6% accurate, 1.4× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{b} \leq 2:\\ \;\;\;\;\frac{1 + a}{2 + a}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(0.5, b, 1\right) \cdot b\right)}^{-1}\\ \end{array} \end{array} \]
      (FPCore (a b)
       :precision binary64
       (if (<= (exp b) 2.0)
         (/ (+ 1.0 a) (+ 2.0 a))
         (pow (* (fma 0.5 b 1.0) b) -1.0)))
      double code(double a, double b) {
      	double tmp;
      	if (exp(b) <= 2.0) {
      		tmp = (1.0 + a) / (2.0 + a);
      	} else {
      		tmp = pow((fma(0.5, b, 1.0) * b), -1.0);
      	}
      	return tmp;
      }
      
      function code(a, b)
      	tmp = 0.0
      	if (exp(b) <= 2.0)
      		tmp = Float64(Float64(1.0 + a) / Float64(2.0 + a));
      	else
      		tmp = Float64(fma(0.5, b, 1.0) * b) ^ -1.0;
      	end
      	return tmp
      end
      
      code[a_, b_] := If[LessEqual[N[Exp[b], $MachinePrecision], 2.0], N[(N[(1.0 + a), $MachinePrecision] / N[(2.0 + a), $MachinePrecision]), $MachinePrecision], N[Power[N[(N[(0.5 * b + 1.0), $MachinePrecision] * b), $MachinePrecision], -1.0], $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;e^{b} \leq 2:\\
      \;\;\;\;\frac{1 + a}{2 + a}\\
      
      \mathbf{else}:\\
      \;\;\;\;{\left(\mathsf{fma}\left(0.5, b, 1\right) \cdot b\right)}^{-1}\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (exp.f64 b) < 2

        1. Initial program 98.4%

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

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

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

            \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
          3. lower-exp.f6476.9

            \[\leadsto \frac{e^{a}}{\color{blue}{e^{a}} + 1} \]
        5. Applied rewrites76.9%

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

          \[\leadsto \frac{e^{a}}{2 + \color{blue}{a}} \]
        7. Step-by-step derivation
          1. Applied rewrites75.7%

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

            \[\leadsto \frac{\color{blue}{1 + a}}{2 + a} \]
          3. Step-by-step derivation
            1. lower-+.f6449.5

              \[\leadsto \frac{\color{blue}{1 + a}}{2 + a} \]
          4. Applied rewrites49.5%

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

          if 2 < (exp.f64 b)

          1. Initial program 100.0%

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

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

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

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

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

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

            \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
          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 rewrites48.6%

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

              \[\leadsto \frac{1}{{b}^{2} \cdot \left(\frac{1}{2} + \color{blue}{\frac{1}{b}}\right)} \]
            3. Step-by-step derivation
              1. Applied rewrites48.6%

                \[\leadsto \frac{1}{\mathsf{fma}\left(0.5, b, 1\right) \cdot b} \]
            4. Recombined 2 regimes into one program.
            5. Final simplification49.2%

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

            Alternative 7: 53.6% accurate, 1.4× speedup?

            \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{b} \leq 2:\\ \;\;\;\;\frac{1 + a}{2 + a}\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(0.5 \cdot b\right) \cdot b\right)}^{-1}\\ \end{array} \end{array} \]
            (FPCore (a b)
             :precision binary64
             (if (<= (exp b) 2.0) (/ (+ 1.0 a) (+ 2.0 a)) (pow (* (* 0.5 b) b) -1.0)))
            double code(double a, double b) {
            	double tmp;
            	if (exp(b) <= 2.0) {
            		tmp = (1.0 + a) / (2.0 + a);
            	} else {
            		tmp = pow(((0.5 * b) * 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(b) <= 2.0d0) then
                    tmp = (1.0d0 + a) / (2.0d0 + a)
                else
                    tmp = ((0.5d0 * b) * b) ** (-1.0d0)
                end if
                code = tmp
            end function
            
            public static double code(double a, double b) {
            	double tmp;
            	if (Math.exp(b) <= 2.0) {
            		tmp = (1.0 + a) / (2.0 + a);
            	} else {
            		tmp = Math.pow(((0.5 * b) * b), -1.0);
            	}
            	return tmp;
            }
            
            def code(a, b):
            	tmp = 0
            	if math.exp(b) <= 2.0:
            		tmp = (1.0 + a) / (2.0 + a)
            	else:
            		tmp = math.pow(((0.5 * b) * b), -1.0)
            	return tmp
            
            function code(a, b)
            	tmp = 0.0
            	if (exp(b) <= 2.0)
            		tmp = Float64(Float64(1.0 + a) / Float64(2.0 + a));
            	else
            		tmp = Float64(Float64(0.5 * b) * b) ^ -1.0;
            	end
            	return tmp
            end
            
            function tmp_2 = code(a, b)
            	tmp = 0.0;
            	if (exp(b) <= 2.0)
            		tmp = (1.0 + a) / (2.0 + a);
            	else
            		tmp = ((0.5 * b) * b) ^ -1.0;
            	end
            	tmp_2 = tmp;
            end
            
            code[a_, b_] := If[LessEqual[N[Exp[b], $MachinePrecision], 2.0], N[(N[(1.0 + a), $MachinePrecision] / N[(2.0 + a), $MachinePrecision]), $MachinePrecision], N[Power[N[(N[(0.5 * b), $MachinePrecision] * b), $MachinePrecision], -1.0], $MachinePrecision]]
            
            \begin{array}{l}
            
            \\
            \begin{array}{l}
            \mathbf{if}\;e^{b} \leq 2:\\
            \;\;\;\;\frac{1 + a}{2 + a}\\
            
            \mathbf{else}:\\
            \;\;\;\;{\left(\left(0.5 \cdot b\right) \cdot b\right)}^{-1}\\
            
            
            \end{array}
            \end{array}
            
            Derivation
            1. Split input into 2 regimes
            2. if (exp.f64 b) < 2

              1. Initial program 98.4%

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

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

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

                  \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                3. lower-exp.f6476.9

                  \[\leadsto \frac{e^{a}}{\color{blue}{e^{a}} + 1} \]
              5. Applied rewrites76.9%

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

                \[\leadsto \frac{e^{a}}{2 + \color{blue}{a}} \]
              7. Step-by-step derivation
                1. Applied rewrites75.7%

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

                  \[\leadsto \frac{\color{blue}{1 + a}}{2 + a} \]
                3. Step-by-step derivation
                  1. lower-+.f6449.5

                    \[\leadsto \frac{\color{blue}{1 + a}}{2 + a} \]
                4. Applied rewrites49.5%

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

                if 2 < (exp.f64 b)

                1. Initial program 100.0%

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

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

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

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

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

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

                  \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
                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 rewrites48.6%

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

                    \[\leadsto \frac{1}{\frac{1}{2} \cdot {b}^{\color{blue}{2}}} \]
                  3. Step-by-step derivation
                    1. Applied rewrites48.6%

                      \[\leadsto \frac{1}{\left(0.5 \cdot b\right) \cdot b} \]
                  4. Recombined 2 regimes into one program.
                  5. Final simplification49.2%

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

                  Alternative 8: 76.9% accurate, 2.5× speedup?

                  \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 1.95 \cdot 10^{+96}:\\ \;\;\;\;\frac{e^{a}}{2}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \end{array} \]
                  (FPCore (a b)
                   :precision binary64
                   (if (<= b 1.95e+96)
                     (/ (exp a) 2.0)
                     (pow (fma (fma (fma 0.16666666666666666 b 0.5) b 1.0) b 2.0) -1.0)))
                  double code(double a, double b) {
                  	double tmp;
                  	if (b <= 1.95e+96) {
                  		tmp = exp(a) / 2.0;
                  	} else {
                  		tmp = pow(fma(fma(fma(0.16666666666666666, b, 0.5), b, 1.0), b, 2.0), -1.0);
                  	}
                  	return tmp;
                  }
                  
                  function code(a, b)
                  	tmp = 0.0
                  	if (b <= 1.95e+96)
                  		tmp = Float64(exp(a) / 2.0);
                  	else
                  		tmp = fma(fma(fma(0.16666666666666666, b, 0.5), b, 1.0), b, 2.0) ^ -1.0;
                  	end
                  	return tmp
                  end
                  
                  code[a_, b_] := If[LessEqual[b, 1.95e+96], N[(N[Exp[a], $MachinePrecision] / 2.0), $MachinePrecision], N[Power[N[(N[(N[(0.16666666666666666 * b + 0.5), $MachinePrecision] * b + 1.0), $MachinePrecision] * b + 2.0), $MachinePrecision], -1.0], $MachinePrecision]]
                  
                  \begin{array}{l}
                  
                  \\
                  \begin{array}{l}
                  \mathbf{if}\;b \leq 1.95 \cdot 10^{+96}:\\
                  \;\;\;\;\frac{e^{a}}{2}\\
                  
                  \mathbf{else}:\\
                  \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), b, 2\right)\right)}^{-1}\\
                  
                  
                  \end{array}
                  \end{array}
                  
                  Derivation
                  1. Split input into 2 regimes
                  2. if b < 1.95e96

                    1. Initial program 98.5%

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

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

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

                        \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                      3. lower-exp.f6473.3

                        \[\leadsto \frac{e^{a}}{\color{blue}{e^{a}} + 1} \]
                    5. Applied rewrites73.3%

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

                      \[\leadsto \frac{e^{a}}{2} \]
                    7. Step-by-step derivation
                      1. Applied rewrites71.6%

                        \[\leadsto \frac{e^{a}}{2} \]

                      if 1.95e96 < b

                      1. Initial program 100.0%

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

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

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

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

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

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

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

                          \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), \color{blue}{b}, 2\right)} \]
                      8. Recombined 2 regimes into one program.
                      9. Final simplification76.6%

                        \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 1.95 \cdot 10^{+96}:\\ \;\;\;\;\frac{e^{a}}{2}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \]
                      10. Add Preprocessing

                      Alternative 9: 71.0% accurate, 2.5× speedup?

                      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 3.6 \cdot 10^{+93}:\\ \;\;\;\;\frac{1 + a}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, a, 0.5\right), a, 1\right), a, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \end{array} \]
                      (FPCore (a b)
                       :precision binary64
                       (if (<= b 3.6e+93)
                         (/ (+ 1.0 a) (fma (fma (fma 0.16666666666666666 a 0.5) a 1.0) a 2.0))
                         (pow (fma (fma (fma 0.16666666666666666 b 0.5) b 1.0) b 2.0) -1.0)))
                      double code(double a, double b) {
                      	double tmp;
                      	if (b <= 3.6e+93) {
                      		tmp = (1.0 + a) / fma(fma(fma(0.16666666666666666, a, 0.5), a, 1.0), a, 2.0);
                      	} else {
                      		tmp = pow(fma(fma(fma(0.16666666666666666, b, 0.5), b, 1.0), b, 2.0), -1.0);
                      	}
                      	return tmp;
                      }
                      
                      function code(a, b)
                      	tmp = 0.0
                      	if (b <= 3.6e+93)
                      		tmp = Float64(Float64(1.0 + a) / fma(fma(fma(0.16666666666666666, a, 0.5), a, 1.0), a, 2.0));
                      	else
                      		tmp = fma(fma(fma(0.16666666666666666, b, 0.5), b, 1.0), b, 2.0) ^ -1.0;
                      	end
                      	return tmp
                      end
                      
                      code[a_, b_] := If[LessEqual[b, 3.6e+93], N[(N[(1.0 + a), $MachinePrecision] / N[(N[(N[(0.16666666666666666 * a + 0.5), $MachinePrecision] * a + 1.0), $MachinePrecision] * a + 2.0), $MachinePrecision]), $MachinePrecision], N[Power[N[(N[(N[(0.16666666666666666 * b + 0.5), $MachinePrecision] * b + 1.0), $MachinePrecision] * b + 2.0), $MachinePrecision], -1.0], $MachinePrecision]]
                      
                      \begin{array}{l}
                      
                      \\
                      \begin{array}{l}
                      \mathbf{if}\;b \leq 3.6 \cdot 10^{+93}:\\
                      \;\;\;\;\frac{1 + a}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, a, 0.5\right), a, 1\right), a, 2\right)}\\
                      
                      \mathbf{else}:\\
                      \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), b, 2\right)\right)}^{-1}\\
                      
                      
                      \end{array}
                      \end{array}
                      
                      Derivation
                      1. Split input into 2 regimes
                      2. if b < 3.5999999999999999e93

                        1. Initial program 98.5%

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

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

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

                            \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                          3. lower-exp.f6473.3

                            \[\leadsto \frac{e^{a}}{\color{blue}{e^{a}} + 1} \]
                        5. Applied rewrites73.3%

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

                          \[\leadsto \frac{e^{a}}{2 + \color{blue}{a}} \]
                        7. Step-by-step derivation
                          1. Applied rewrites72.2%

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

                            \[\leadsto \frac{\color{blue}{1 + a}}{2 + a} \]
                          3. Step-by-step derivation
                            1. lower-+.f6444.6

                              \[\leadsto \frac{\color{blue}{1 + a}}{2 + a} \]
                          4. Applied rewrites44.6%

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

                            \[\leadsto \frac{1 + a}{2 + \color{blue}{a \cdot \left(1 + a \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot a\right)\right)}} \]
                          6. Step-by-step derivation
                            1. Applied rewrites61.6%

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

                            if 3.5999999999999999e93 < b

                            1. Initial program 100.0%

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

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

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

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

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

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

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

                                \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), \color{blue}{b}, 2\right)} \]
                            8. Recombined 2 regimes into one program.
                            9. Final simplification68.5%

                              \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 3.6 \cdot 10^{+93}:\\ \;\;\;\;\frac{1 + a}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, a, 0.5\right), a, 1\right), a, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \]
                            10. Add Preprocessing

                            Alternative 10: 67.7% accurate, 2.5× speedup?

                            \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 3.6 \cdot 10^{+93}:\\ \;\;\;\;\frac{1 + a}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \end{array} \]
                            (FPCore (a b)
                             :precision binary64
                             (if (<= b 3.6e+93)
                               (/ (+ 1.0 a) (fma (fma 0.5 a 1.0) a 2.0))
                               (pow (fma (fma (fma 0.16666666666666666 b 0.5) b 1.0) b 2.0) -1.0)))
                            double code(double a, double b) {
                            	double tmp;
                            	if (b <= 3.6e+93) {
                            		tmp = (1.0 + a) / fma(fma(0.5, a, 1.0), a, 2.0);
                            	} else {
                            		tmp = pow(fma(fma(fma(0.16666666666666666, b, 0.5), b, 1.0), b, 2.0), -1.0);
                            	}
                            	return tmp;
                            }
                            
                            function code(a, b)
                            	tmp = 0.0
                            	if (b <= 3.6e+93)
                            		tmp = Float64(Float64(1.0 + a) / fma(fma(0.5, a, 1.0), a, 2.0));
                            	else
                            		tmp = fma(fma(fma(0.16666666666666666, b, 0.5), b, 1.0), b, 2.0) ^ -1.0;
                            	end
                            	return tmp
                            end
                            
                            code[a_, b_] := If[LessEqual[b, 3.6e+93], N[(N[(1.0 + a), $MachinePrecision] / N[(N[(0.5 * a + 1.0), $MachinePrecision] * a + 2.0), $MachinePrecision]), $MachinePrecision], N[Power[N[(N[(N[(0.16666666666666666 * b + 0.5), $MachinePrecision] * b + 1.0), $MachinePrecision] * b + 2.0), $MachinePrecision], -1.0], $MachinePrecision]]
                            
                            \begin{array}{l}
                            
                            \\
                            \begin{array}{l}
                            \mathbf{if}\;b \leq 3.6 \cdot 10^{+93}:\\
                            \;\;\;\;\frac{1 + a}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)}\\
                            
                            \mathbf{else}:\\
                            \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), b, 2\right)\right)}^{-1}\\
                            
                            
                            \end{array}
                            \end{array}
                            
                            Derivation
                            1. Split input into 2 regimes
                            2. if b < 3.5999999999999999e93

                              1. Initial program 98.5%

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

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

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

                                  \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                                3. lower-exp.f6473.3

                                  \[\leadsto \frac{e^{a}}{\color{blue}{e^{a}} + 1} \]
                              5. Applied rewrites73.3%

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

                                \[\leadsto \frac{e^{a}}{2 + \color{blue}{a}} \]
                              7. Step-by-step derivation
                                1. Applied rewrites72.2%

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

                                  \[\leadsto \frac{\color{blue}{1 + a}}{2 + a} \]
                                3. Step-by-step derivation
                                  1. lower-+.f6444.6

                                    \[\leadsto \frac{\color{blue}{1 + a}}{2 + a} \]
                                4. Applied rewrites44.6%

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

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

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

                                  if 3.5999999999999999e93 < b

                                  1. Initial program 100.0%

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

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

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

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

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

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

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

                                      \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), \color{blue}{b}, 2\right)} \]
                                  8. Recombined 2 regimes into one program.
                                  9. Final simplification66.2%

                                    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 3.6 \cdot 10^{+93}:\\ \;\;\;\;\frac{1 + a}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \]
                                  10. Add Preprocessing

                                  Alternative 11: 63.2% accurate, 2.6× speedup?

                                  \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 3.6 \cdot 10^{+93}:\\ \;\;\;\;\frac{1 + a}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \end{array} \]
                                  (FPCore (a b)
                                   :precision binary64
                                   (if (<= b 3.6e+93)
                                     (/ (+ 1.0 a) (fma (fma 0.5 a 1.0) a 2.0))
                                     (pow (fma (fma 0.5 b 1.0) b 2.0) -1.0)))
                                  double code(double a, double b) {
                                  	double tmp;
                                  	if (b <= 3.6e+93) {
                                  		tmp = (1.0 + a) / fma(fma(0.5, a, 1.0), a, 2.0);
                                  	} else {
                                  		tmp = pow(fma(fma(0.5, b, 1.0), b, 2.0), -1.0);
                                  	}
                                  	return tmp;
                                  }
                                  
                                  function code(a, b)
                                  	tmp = 0.0
                                  	if (b <= 3.6e+93)
                                  		tmp = Float64(Float64(1.0 + a) / fma(fma(0.5, a, 1.0), a, 2.0));
                                  	else
                                  		tmp = fma(fma(0.5, b, 1.0), b, 2.0) ^ -1.0;
                                  	end
                                  	return tmp
                                  end
                                  
                                  code[a_, b_] := If[LessEqual[b, 3.6e+93], N[(N[(1.0 + a), $MachinePrecision] / N[(N[(0.5 * a + 1.0), $MachinePrecision] * a + 2.0), $MachinePrecision]), $MachinePrecision], N[Power[N[(N[(0.5 * b + 1.0), $MachinePrecision] * b + 2.0), $MachinePrecision], -1.0], $MachinePrecision]]
                                  
                                  \begin{array}{l}
                                  
                                  \\
                                  \begin{array}{l}
                                  \mathbf{if}\;b \leq 3.6 \cdot 10^{+93}:\\
                                  \;\;\;\;\frac{1 + a}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)}\\
                                  
                                  \mathbf{else}:\\
                                  \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), b, 2\right)\right)}^{-1}\\
                                  
                                  
                                  \end{array}
                                  \end{array}
                                  
                                  Derivation
                                  1. Split input into 2 regimes
                                  2. if b < 3.5999999999999999e93

                                    1. Initial program 98.5%

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

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

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

                                        \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                                      3. lower-exp.f6473.3

                                        \[\leadsto \frac{e^{a}}{\color{blue}{e^{a}} + 1} \]
                                    5. Applied rewrites73.3%

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

                                      \[\leadsto \frac{e^{a}}{2 + \color{blue}{a}} \]
                                    7. Step-by-step derivation
                                      1. Applied rewrites72.2%

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

                                        \[\leadsto \frac{\color{blue}{1 + a}}{2 + a} \]
                                      3. Step-by-step derivation
                                        1. lower-+.f6444.6

                                          \[\leadsto \frac{\color{blue}{1 + a}}{2 + a} \]
                                      4. Applied rewrites44.6%

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

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

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

                                        if 3.5999999999999999e93 < b

                                        1. Initial program 100.0%

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

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

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

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

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

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

                                          \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
                                        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 rewrites69.0%

                                            \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), \color{blue}{b}, 2\right)} \]
                                        8. Recombined 2 regimes into one program.
                                        9. Final simplification60.7%

                                          \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 3.6 \cdot 10^{+93}:\\ \;\;\;\;\frac{1 + a}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \]
                                        10. Add Preprocessing

                                        Alternative 12: 53.7% accurate, 2.6× speedup?

                                        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 2 \cdot 10^{-103}:\\ \;\;\;\;\frac{1 + a}{2 + a}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \end{array} \]
                                        (FPCore (a b)
                                         :precision binary64
                                         (if (<= b 2e-103)
                                           (/ (+ 1.0 a) (+ 2.0 a))
                                           (pow (fma (fma 0.5 b 1.0) b 2.0) -1.0)))
                                        double code(double a, double b) {
                                        	double tmp;
                                        	if (b <= 2e-103) {
                                        		tmp = (1.0 + a) / (2.0 + a);
                                        	} else {
                                        		tmp = pow(fma(fma(0.5, b, 1.0), b, 2.0), -1.0);
                                        	}
                                        	return tmp;
                                        }
                                        
                                        function code(a, b)
                                        	tmp = 0.0
                                        	if (b <= 2e-103)
                                        		tmp = Float64(Float64(1.0 + a) / Float64(2.0 + a));
                                        	else
                                        		tmp = fma(fma(0.5, b, 1.0), b, 2.0) ^ -1.0;
                                        	end
                                        	return tmp
                                        end
                                        
                                        code[a_, b_] := If[LessEqual[b, 2e-103], N[(N[(1.0 + a), $MachinePrecision] / N[(2.0 + a), $MachinePrecision]), $MachinePrecision], N[Power[N[(N[(0.5 * b + 1.0), $MachinePrecision] * b + 2.0), $MachinePrecision], -1.0], $MachinePrecision]]
                                        
                                        \begin{array}{l}
                                        
                                        \\
                                        \begin{array}{l}
                                        \mathbf{if}\;b \leq 2 \cdot 10^{-103}:\\
                                        \;\;\;\;\frac{1 + a}{2 + a}\\
                                        
                                        \mathbf{else}:\\
                                        \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), b, 2\right)\right)}^{-1}\\
                                        
                                        
                                        \end{array}
                                        \end{array}
                                        
                                        Derivation
                                        1. Split input into 2 regimes
                                        2. if b < 1.99999999999999992e-103

                                          1. Initial program 98.2%

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

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

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

                                              \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                                            3. lower-exp.f6474.5

                                              \[\leadsto \frac{e^{a}}{\color{blue}{e^{a}} + 1} \]
                                          5. Applied rewrites74.5%

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

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

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

                                              \[\leadsto \frac{\color{blue}{1 + a}}{2 + a} \]
                                            3. Step-by-step derivation
                                              1. lower-+.f6448.0

                                                \[\leadsto \frac{\color{blue}{1 + a}}{2 + a} \]
                                            4. Applied rewrites48.0%

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

                                            if 1.99999999999999992e-103 < b

                                            1. Initial program 100.0%

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

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

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

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

                                                \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                              4. lower-exp.f6492.4

                                                \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
                                            5. Applied rewrites92.4%

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

                                              \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                            7. Step-by-step derivation
                                              1. Applied rewrites51.9%

                                                \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), \color{blue}{b}, 2\right)} \]
                                            8. Recombined 2 regimes into one program.
                                            9. Final simplification49.4%

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

                                            Alternative 13: 39.9% accurate, 21.0× speedup?

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

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

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

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

                                                \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                                              3. lower-exp.f6465.1

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

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

                                              \[\leadsto \frac{e^{a}}{2 + \color{blue}{a}} \]
                                            7. Step-by-step derivation
                                              1. Applied rewrites64.2%

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

                                                \[\leadsto \frac{\color{blue}{1}}{2 + a} \]
                                              3. Step-by-step derivation
                                                1. Applied rewrites36.8%

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

                                                Alternative 14: 39.4% accurate, 315.0× speedup?

                                                \[\begin{array}{l} \\ 0.5 \end{array} \]
                                                (FPCore (a b) :precision binary64 0.5)
                                                double code(double a, double b) {
                                                	return 0.5;
                                                }
                                                
                                                real(8) function code(a, b)
                                                    real(8), intent (in) :: a
                                                    real(8), intent (in) :: b
                                                    code = 0.5d0
                                                end function
                                                
                                                public static double code(double a, double b) {
                                                	return 0.5;
                                                }
                                                
                                                def code(a, b):
                                                	return 0.5
                                                
                                                function code(a, b)
                                                	return 0.5
                                                end
                                                
                                                function tmp = code(a, b)
                                                	tmp = 0.5;
                                                end
                                                
                                                code[a_, b_] := 0.5
                                                
                                                \begin{array}{l}
                                                
                                                \\
                                                0.5
                                                \end{array}
                                                
                                                Derivation
                                                1. Initial program 98.8%

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

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

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

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

                                                    \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                  4. lower-exp.f6479.0

                                                    \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
                                                5. Applied rewrites79.0%

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

                                                  \[\leadsto \frac{1}{2} \]
                                                7. Step-by-step derivation
                                                  1. Applied rewrites36.2%

                                                    \[\leadsto 0.5 \]
                                                  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 2024318 
                                                  (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))))