Quotient of sum of exps

Percentage Accurate: 99.0% → 100.0%
Time: 8.4s
Alternatives: 14
Speedup: 2.9×

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: 99.0% 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: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ e^{-\mathsf{log1p}\left(e^{b - a}\right)} \end{array} \]
(FPCore (a b) :precision binary64 (exp (- (log1p (exp (- b a))))))
double code(double a, double b) {
	return exp(-log1p(exp((b - a))));
}
public static double code(double a, double b) {
	return Math.exp(-Math.log1p(Math.exp((b - a))));
}
def code(a, b):
	return math.exp(-math.log1p(math.exp((b - a))))
function code(a, b)
	return exp(Float64(-log1p(exp(Float64(b - a)))))
end
code[a_, b_] := N[Exp[(-N[Log[1 + N[Exp[N[(b - a), $MachinePrecision]], $MachinePrecision]], $MachinePrecision])], $MachinePrecision]
\begin{array}{l}

\\
e^{-\mathsf{log1p}\left(e^{b - a}\right)}
\end{array}
Derivation
  1. Initial program 98.8%

    \[\frac{e^{a}}{e^{a} + e^{b}} \]
  2. Step-by-step derivation
    1. *-lft-identity98.8%

      \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
    2. associate-/l*98.8%

      \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
    3. remove-double-div98.8%

      \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
    4. exp-neg98.8%

      \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
    5. associate-/r/98.8%

      \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
    6. /-rgt-identity98.8%

      \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
    7. *-commutative98.8%

      \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
    8. distribute-rgt-in70.7%

      \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
    9. exp-neg70.7%

      \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
    10. rgt-mult-inverse98.8%

      \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
    11. prod-exp100.0%

      \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
    12. unsub-neg100.0%

      \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
  4. Step-by-step derivation
    1. add-exp-log100.0%

      \[\leadsto \color{blue}{e^{\log \left(\frac{1}{1 + e^{b - a}}\right)}} \]
    2. log-rec100.0%

      \[\leadsto e^{\color{blue}{-\log \left(1 + e^{b - a}\right)}} \]
    3. log1p-udef100.0%

      \[\leadsto e^{-\color{blue}{\mathsf{log1p}\left(e^{b - a}\right)}} \]
  5. Applied egg-rr100.0%

    \[\leadsto \color{blue}{e^{-\mathsf{log1p}\left(e^{b - a}\right)}} \]
  6. Final simplification100.0%

    \[\leadsto e^{-\mathsf{log1p}\left(e^{b - a}\right)} \]

Alternative 2: 67.7% accurate, 1.5× speedup?

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

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

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


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

    1. Initial program 98.8%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity98.8%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*98.8%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div98.8%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg98.8%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/98.8%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity98.8%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative98.8%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in70.1%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg70.1%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse98.8%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in b around 0 66.1%

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

    if 1 < (exp.f64 a)

    1. Initial program 99.7%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity99.7%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*99.7%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div99.7%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg99.4%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/99.4%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity99.4%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative99.4%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in99.7%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg100.0%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse100.0%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in a around 0 74.8%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification66.3%

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

Alternative 3: 72.3% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := b + a \cdot \left(-1 - b\right)\\ \mathbf{if}\;e^{a} \leq 0:\\ \;\;\;\;\frac{e^{a}}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\frac{t_0 \cdot t_0 - 4}{t_0 - 2}}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (let* ((t_0 (+ b (* a (- -1.0 b)))))
   (if (<= (exp a) 0.0)
     (/ (exp a) b)
     (/ 1.0 (/ (- (* t_0 t_0) 4.0) (- t_0 2.0))))))
double code(double a, double b) {
	double t_0 = b + (a * (-1.0 - b));
	double tmp;
	if (exp(a) <= 0.0) {
		tmp = exp(a) / b;
	} else {
		tmp = 1.0 / (((t_0 * t_0) - 4.0) / (t_0 - 2.0));
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: t_0
    real(8) :: tmp
    t_0 = b + (a * ((-1.0d0) - b))
    if (exp(a) <= 0.0d0) then
        tmp = exp(a) / b
    else
        tmp = 1.0d0 / (((t_0 * t_0) - 4.0d0) / (t_0 - 2.0d0))
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double t_0 = b + (a * (-1.0 - b));
	double tmp;
	if (Math.exp(a) <= 0.0) {
		tmp = Math.exp(a) / b;
	} else {
		tmp = 1.0 / (((t_0 * t_0) - 4.0) / (t_0 - 2.0));
	}
	return tmp;
}
def code(a, b):
	t_0 = b + (a * (-1.0 - b))
	tmp = 0
	if math.exp(a) <= 0.0:
		tmp = math.exp(a) / b
	else:
		tmp = 1.0 / (((t_0 * t_0) - 4.0) / (t_0 - 2.0))
	return tmp
function code(a, b)
	t_0 = Float64(b + Float64(a * Float64(-1.0 - b)))
	tmp = 0.0
	if (exp(a) <= 0.0)
		tmp = Float64(exp(a) / b);
	else
		tmp = Float64(1.0 / Float64(Float64(Float64(t_0 * t_0) - 4.0) / Float64(t_0 - 2.0)));
	end
	return tmp
end
function tmp_2 = code(a, b)
	t_0 = b + (a * (-1.0 - b));
	tmp = 0.0;
	if (exp(a) <= 0.0)
		tmp = exp(a) / b;
	else
		tmp = 1.0 / (((t_0 * t_0) - 4.0) / (t_0 - 2.0));
	end
	tmp_2 = tmp;
end
code[a_, b_] := Block[{t$95$0 = N[(b + N[(a * N[(-1.0 - b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[Exp[a], $MachinePrecision], 0.0], N[(N[Exp[a], $MachinePrecision] / b), $MachinePrecision], N[(1.0 / N[(N[(N[(t$95$0 * t$95$0), $MachinePrecision] - 4.0), $MachinePrecision] / N[(t$95$0 - 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := b + a \cdot \left(-1 - b\right)\\
\mathbf{if}\;e^{a} \leq 0:\\
\;\;\;\;\frac{e^{a}}{b}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{\frac{t_0 \cdot t_0 - 4}{t_0 - 2}}\\


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

    1. Initial program 96.0%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity96.0%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*96.0%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div96.0%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg96.0%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/96.0%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity96.0%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative96.0%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in0.0%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg0.0%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse96.0%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in b around 0 68.0%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    5. Step-by-step derivation
      1. distribute-rgt1-in98.7%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp98.7%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/98.7%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. +-commutative98.7%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{\left(1 + b\right)} \cdot 1}{e^{a}}} \]
      5. *-rgt-identity98.7%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    6. Simplified98.7%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    7. Taylor expanded in b around inf 98.7%

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

    if 0.0 < (exp.f64 a)

    1. Initial program 100.0%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity100.0%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*100.0%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div100.0%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg99.9%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/99.9%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity99.9%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative99.9%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in100.0%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg100.0%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse100.0%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in b around 0 48.4%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    5. Step-by-step derivation
      1. distribute-rgt1-in48.4%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp48.4%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/48.4%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. +-commutative48.4%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{\left(1 + b\right)} \cdot 1}{e^{a}}} \]
      5. *-rgt-identity48.4%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    6. Simplified48.4%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    7. Taylor expanded in a around 0 47.4%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
    8. Step-by-step derivation
      1. +-commutative47.4%

        \[\leadsto \frac{1}{\color{blue}{\left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right) + 2}} \]
      2. associate-+l+47.4%

        \[\leadsto \frac{1}{\color{blue}{b + \left(-1 \cdot \left(a \cdot \left(1 + b\right)\right) + 2\right)}} \]
      3. mul-1-neg47.4%

        \[\leadsto \frac{1}{b + \left(\color{blue}{\left(-a \cdot \left(1 + b\right)\right)} + 2\right)} \]
      4. distribute-rgt-neg-in47.4%

        \[\leadsto \frac{1}{b + \left(\color{blue}{a \cdot \left(-\left(1 + b\right)\right)} + 2\right)} \]
      5. neg-sub047.4%

        \[\leadsto \frac{1}{b + \left(a \cdot \color{blue}{\left(0 - \left(1 + b\right)\right)} + 2\right)} \]
      6. associate--r+47.4%

        \[\leadsto \frac{1}{b + \left(a \cdot \color{blue}{\left(\left(0 - 1\right) - b\right)} + 2\right)} \]
      7. metadata-eval47.4%

        \[\leadsto \frac{1}{b + \left(a \cdot \left(\color{blue}{-1} - b\right) + 2\right)} \]
    9. Simplified47.4%

      \[\leadsto \frac{1}{\color{blue}{b + \left(a \cdot \left(-1 - b\right) + 2\right)}} \]
    10. Step-by-step derivation
      1. associate-+r+47.4%

        \[\leadsto \frac{1}{\color{blue}{\left(b + a \cdot \left(-1 - b\right)\right) + 2}} \]
      2. flip-+55.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{\left(b + a \cdot \left(-1 - b\right)\right) \cdot \left(b + a \cdot \left(-1 - b\right)\right) - 2 \cdot 2}{\left(b + a \cdot \left(-1 - b\right)\right) - 2}}} \]
      3. metadata-eval55.7%

        \[\leadsto \frac{1}{\frac{\left(b + a \cdot \left(-1 - b\right)\right) \cdot \left(b + a \cdot \left(-1 - b\right)\right) - \color{blue}{4}}{\left(b + a \cdot \left(-1 - b\right)\right) - 2}} \]
    11. Applied egg-rr55.7%

      \[\leadsto \frac{1}{\color{blue}{\frac{\left(b + a \cdot \left(-1 - b\right)\right) \cdot \left(b + a \cdot \left(-1 - b\right)\right) - 4}{\left(b + a \cdot \left(-1 - b\right)\right) - 2}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification68.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;e^{a} \leq 0:\\ \;\;\;\;\frac{e^{a}}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\frac{\left(b + a \cdot \left(-1 - b\right)\right) \cdot \left(b + a \cdot \left(-1 - b\right)\right) - 4}{\left(b + a \cdot \left(-1 - b\right)\right) - 2}}\\ \end{array} \]

Alternative 4: 98.4% accurate, 2.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -6500000:\\ \;\;\;\;\frac{e^{a}}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{1 + e^{b}}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= a -6500000.0) (/ (exp a) b) (/ 1.0 (+ 1.0 (exp b)))))
double code(double a, double b) {
	double tmp;
	if (a <= -6500000.0) {
		tmp = exp(a) / b;
	} else {
		tmp = 1.0 / (1.0 + exp(b));
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (a <= (-6500000.0d0)) then
        tmp = exp(a) / b
    else
        tmp = 1.0d0 / (1.0d0 + exp(b))
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (a <= -6500000.0) {
		tmp = Math.exp(a) / b;
	} else {
		tmp = 1.0 / (1.0 + Math.exp(b));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if a <= -6500000.0:
		tmp = math.exp(a) / b
	else:
		tmp = 1.0 / (1.0 + math.exp(b))
	return tmp
function code(a, b)
	tmp = 0.0
	if (a <= -6500000.0)
		tmp = Float64(exp(a) / b);
	else
		tmp = Float64(1.0 / Float64(1.0 + exp(b)));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (a <= -6500000.0)
		tmp = exp(a) / b;
	else
		tmp = 1.0 / (1.0 + exp(b));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[a, -6500000.0], N[(N[Exp[a], $MachinePrecision] / b), $MachinePrecision], N[(1.0 / N[(1.0 + N[Exp[b], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \leq -6500000:\\
\;\;\;\;\frac{e^{a}}{b}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if a < -6.5e6

    1. Initial program 97.2%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity97.2%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*97.2%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div97.2%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg97.2%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/97.2%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity97.2%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative97.2%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in0.0%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg0.0%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse97.2%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in b around 0 69.0%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    5. Step-by-step derivation
      1. distribute-rgt1-in100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp100.0%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. +-commutative100.0%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{\left(1 + b\right)} \cdot 1}{e^{a}}} \]
      5. *-rgt-identity100.0%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    6. Simplified100.0%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    7. Taylor expanded in b around inf 100.0%

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

    if -6.5e6 < a

    1. Initial program 99.4%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity99.4%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*99.4%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div99.4%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg99.4%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/99.4%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity99.4%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative99.4%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in97.8%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg97.8%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse99.4%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in a around 0 98.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -6500000:\\ \;\;\;\;\frac{e^{a}}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{1 + e^{b}}\\ \end{array} \]

Alternative 5: 100.0% accurate, 2.9× speedup?

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

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

    \[\frac{e^{a}}{e^{a} + e^{b}} \]
  2. Step-by-step derivation
    1. *-lft-identity98.8%

      \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
    2. associate-/l*98.8%

      \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
    3. remove-double-div98.8%

      \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
    4. exp-neg98.8%

      \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
    5. associate-/r/98.8%

      \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
    6. /-rgt-identity98.8%

      \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
    7. *-commutative98.8%

      \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
    8. distribute-rgt-in70.7%

      \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
    9. exp-neg70.7%

      \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
    10. rgt-mult-inverse98.8%

      \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
    11. prod-exp100.0%

      \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
    12. unsub-neg100.0%

      \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
  4. Final simplification100.0%

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

Alternative 6: 64.9% accurate, 11.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := b + a \cdot \left(-1 - b\right)\\ \mathbf{if}\;b \leq -1550000:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\frac{t_0 \cdot t_0 - 4}{\left(-2\right) - a}}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (let* ((t_0 (+ b (* a (- -1.0 b)))))
   (if (<= b -1550000.0) 0.5 (/ 1.0 (/ (- (* t_0 t_0) 4.0) (- (- 2.0) a))))))
double code(double a, double b) {
	double t_0 = b + (a * (-1.0 - b));
	double tmp;
	if (b <= -1550000.0) {
		tmp = 0.5;
	} else {
		tmp = 1.0 / (((t_0 * t_0) - 4.0) / (-2.0 - a));
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: t_0
    real(8) :: tmp
    t_0 = b + (a * ((-1.0d0) - b))
    if (b <= (-1550000.0d0)) then
        tmp = 0.5d0
    else
        tmp = 1.0d0 / (((t_0 * t_0) - 4.0d0) / (-2.0d0 - a))
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double t_0 = b + (a * (-1.0 - b));
	double tmp;
	if (b <= -1550000.0) {
		tmp = 0.5;
	} else {
		tmp = 1.0 / (((t_0 * t_0) - 4.0) / (-2.0 - a));
	}
	return tmp;
}
def code(a, b):
	t_0 = b + (a * (-1.0 - b))
	tmp = 0
	if b <= -1550000.0:
		tmp = 0.5
	else:
		tmp = 1.0 / (((t_0 * t_0) - 4.0) / (-2.0 - a))
	return tmp
function code(a, b)
	t_0 = Float64(b + Float64(a * Float64(-1.0 - b)))
	tmp = 0.0
	if (b <= -1550000.0)
		tmp = 0.5;
	else
		tmp = Float64(1.0 / Float64(Float64(Float64(t_0 * t_0) - 4.0) / Float64(Float64(-2.0) - a)));
	end
	return tmp
end
function tmp_2 = code(a, b)
	t_0 = b + (a * (-1.0 - b));
	tmp = 0.0;
	if (b <= -1550000.0)
		tmp = 0.5;
	else
		tmp = 1.0 / (((t_0 * t_0) - 4.0) / (-2.0 - a));
	end
	tmp_2 = tmp;
end
code[a_, b_] := Block[{t$95$0 = N[(b + N[(a * N[(-1.0 - b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[b, -1550000.0], 0.5, N[(1.0 / N[(N[(N[(t$95$0 * t$95$0), $MachinePrecision] - 4.0), $MachinePrecision] / N[((-2.0) - a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := b + a \cdot \left(-1 - b\right)\\
\mathbf{if}\;b \leq -1550000:\\
\;\;\;\;0.5\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{\frac{t_0 \cdot t_0 - 4}{\left(-2\right) - a}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < -1.55e6

    1. Initial program 96.6%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity96.6%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*96.6%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div96.6%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg96.6%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/96.6%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity96.6%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative96.6%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in96.6%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg96.6%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse96.6%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in a around 0 98.4%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
    5. Taylor expanded in b around 0 18.5%

      \[\leadsto \color{blue}{0.5} \]

    if -1.55e6 < b

    1. Initial program 99.5%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity99.5%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*99.5%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div99.5%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg99.4%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/99.4%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity99.4%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative99.4%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in62.9%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg62.9%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse99.5%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in b around 0 69.7%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    5. Step-by-step derivation
      1. distribute-rgt1-in80.9%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp80.9%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/80.9%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. +-commutative80.9%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{\left(1 + b\right)} \cdot 1}{e^{a}}} \]
      5. *-rgt-identity80.9%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    6. Simplified80.9%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    7. Taylor expanded in a around 0 53.2%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
    8. Step-by-step derivation
      1. +-commutative53.2%

        \[\leadsto \frac{1}{\color{blue}{\left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right) + 2}} \]
      2. associate-+l+53.2%

        \[\leadsto \frac{1}{\color{blue}{b + \left(-1 \cdot \left(a \cdot \left(1 + b\right)\right) + 2\right)}} \]
      3. mul-1-neg53.2%

        \[\leadsto \frac{1}{b + \left(\color{blue}{\left(-a \cdot \left(1 + b\right)\right)} + 2\right)} \]
      4. distribute-rgt-neg-in53.2%

        \[\leadsto \frac{1}{b + \left(\color{blue}{a \cdot \left(-\left(1 + b\right)\right)} + 2\right)} \]
      5. neg-sub053.2%

        \[\leadsto \frac{1}{b + \left(a \cdot \color{blue}{\left(0 - \left(1 + b\right)\right)} + 2\right)} \]
      6. associate--r+53.2%

        \[\leadsto \frac{1}{b + \left(a \cdot \color{blue}{\left(\left(0 - 1\right) - b\right)} + 2\right)} \]
      7. metadata-eval53.2%

        \[\leadsto \frac{1}{b + \left(a \cdot \left(\color{blue}{-1} - b\right) + 2\right)} \]
    9. Simplified53.2%

      \[\leadsto \frac{1}{\color{blue}{b + \left(a \cdot \left(-1 - b\right) + 2\right)}} \]
    10. Step-by-step derivation
      1. associate-+r+53.2%

        \[\leadsto \frac{1}{\color{blue}{\left(b + a \cdot \left(-1 - b\right)\right) + 2}} \]
      2. flip-+68.6%

        \[\leadsto \frac{1}{\color{blue}{\frac{\left(b + a \cdot \left(-1 - b\right)\right) \cdot \left(b + a \cdot \left(-1 - b\right)\right) - 2 \cdot 2}{\left(b + a \cdot \left(-1 - b\right)\right) - 2}}} \]
      3. metadata-eval68.6%

        \[\leadsto \frac{1}{\frac{\left(b + a \cdot \left(-1 - b\right)\right) \cdot \left(b + a \cdot \left(-1 - b\right)\right) - \color{blue}{4}}{\left(b + a \cdot \left(-1 - b\right)\right) - 2}} \]
    11. Applied egg-rr68.6%

      \[\leadsto \frac{1}{\color{blue}{\frac{\left(b + a \cdot \left(-1 - b\right)\right) \cdot \left(b + a \cdot \left(-1 - b\right)\right) - 4}{\left(b + a \cdot \left(-1 - b\right)\right) - 2}}} \]
    12. Taylor expanded in b around 0 77.0%

      \[\leadsto \frac{1}{\frac{\left(b + a \cdot \left(-1 - b\right)\right) \cdot \left(b + a \cdot \left(-1 - b\right)\right) - 4}{\color{blue}{-1 \cdot a} - 2}} \]
    13. Step-by-step derivation
      1. neg-mul-177.0%

        \[\leadsto \frac{1}{\frac{\left(b + a \cdot \left(-1 - b\right)\right) \cdot \left(b + a \cdot \left(-1 - b\right)\right) - 4}{\color{blue}{\left(-a\right)} - 2}} \]
    14. Simplified77.0%

      \[\leadsto \frac{1}{\frac{\left(b + a \cdot \left(-1 - b\right)\right) \cdot \left(b + a \cdot \left(-1 - b\right)\right) - 4}{\color{blue}{\left(-a\right)} - 2}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification63.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -1550000:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\frac{\left(b + a \cdot \left(-1 - b\right)\right) \cdot \left(b + a \cdot \left(-1 - b\right)\right) - 4}{\left(-2\right) - a}}\\ \end{array} \]

Alternative 7: 45.2% accurate, 23.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -56000:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b + \left(a \cdot \left(-1 - b\right) + 2\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b -56000.0) 0.5 (/ 1.0 (+ b (+ (* a (- -1.0 b)) 2.0)))))
double code(double a, double b) {
	double tmp;
	if (b <= -56000.0) {
		tmp = 0.5;
	} else {
		tmp = 1.0 / (b + ((a * (-1.0 - b)) + 2.0));
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (b <= (-56000.0d0)) then
        tmp = 0.5d0
    else
        tmp = 1.0d0 / (b + ((a * ((-1.0d0) - b)) + 2.0d0))
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (b <= -56000.0) {
		tmp = 0.5;
	} else {
		tmp = 1.0 / (b + ((a * (-1.0 - b)) + 2.0));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= -56000.0:
		tmp = 0.5
	else:
		tmp = 1.0 / (b + ((a * (-1.0 - b)) + 2.0))
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= -56000.0)
		tmp = 0.5;
	else
		tmp = Float64(1.0 / Float64(b + Float64(Float64(a * Float64(-1.0 - b)) + 2.0)));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= -56000.0)
		tmp = 0.5;
	else
		tmp = 1.0 / (b + ((a * (-1.0 - b)) + 2.0));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, -56000.0], 0.5, N[(1.0 / N[(b + N[(N[(a * N[(-1.0 - b), $MachinePrecision]), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -56000:\\
\;\;\;\;0.5\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{b + \left(a \cdot \left(-1 - b\right) + 2\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < -56000

    1. Initial program 96.6%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity96.6%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*96.6%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div96.6%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg96.6%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/96.6%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity96.6%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative96.6%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in96.6%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg96.6%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse96.6%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in a around 0 98.4%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
    5. Taylor expanded in b around 0 18.5%

      \[\leadsto \color{blue}{0.5} \]

    if -56000 < b

    1. Initial program 99.5%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity99.5%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*99.5%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div99.5%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg99.4%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/99.4%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity99.4%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative99.4%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in62.9%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg62.9%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse99.5%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in b around 0 69.7%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    5. Step-by-step derivation
      1. distribute-rgt1-in80.9%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp80.9%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/80.9%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. +-commutative80.9%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{\left(1 + b\right)} \cdot 1}{e^{a}}} \]
      5. *-rgt-identity80.9%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    6. Simplified80.9%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    7. Taylor expanded in a around 0 53.2%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
    8. Step-by-step derivation
      1. +-commutative53.2%

        \[\leadsto \frac{1}{\color{blue}{\left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right) + 2}} \]
      2. associate-+l+53.2%

        \[\leadsto \frac{1}{\color{blue}{b + \left(-1 \cdot \left(a \cdot \left(1 + b\right)\right) + 2\right)}} \]
      3. mul-1-neg53.2%

        \[\leadsto \frac{1}{b + \left(\color{blue}{\left(-a \cdot \left(1 + b\right)\right)} + 2\right)} \]
      4. distribute-rgt-neg-in53.2%

        \[\leadsto \frac{1}{b + \left(\color{blue}{a \cdot \left(-\left(1 + b\right)\right)} + 2\right)} \]
      5. neg-sub053.2%

        \[\leadsto \frac{1}{b + \left(a \cdot \color{blue}{\left(0 - \left(1 + b\right)\right)} + 2\right)} \]
      6. associate--r+53.2%

        \[\leadsto \frac{1}{b + \left(a \cdot \color{blue}{\left(\left(0 - 1\right) - b\right)} + 2\right)} \]
      7. metadata-eval53.2%

        \[\leadsto \frac{1}{b + \left(a \cdot \left(\color{blue}{-1} - b\right) + 2\right)} \]
    9. Simplified53.2%

      \[\leadsto \frac{1}{\color{blue}{b + \left(a \cdot \left(-1 - b\right) + 2\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification45.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -56000:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b + \left(a \cdot \left(-1 - b\right) + 2\right)}\\ \end{array} \]

Alternative 8: 45.2% accurate, 23.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -56000:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{1 + \left(1 - a\right) \cdot \left(b + 1\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b -56000.0) 0.5 (/ 1.0 (+ 1.0 (* (- 1.0 a) (+ b 1.0))))))
double code(double a, double b) {
	double tmp;
	if (b <= -56000.0) {
		tmp = 0.5;
	} else {
		tmp = 1.0 / (1.0 + ((1.0 - a) * (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 (b <= (-56000.0d0)) then
        tmp = 0.5d0
    else
        tmp = 1.0d0 / (1.0d0 + ((1.0d0 - a) * (b + 1.0d0)))
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (b <= -56000.0) {
		tmp = 0.5;
	} else {
		tmp = 1.0 / (1.0 + ((1.0 - a) * (b + 1.0)));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= -56000.0:
		tmp = 0.5
	else:
		tmp = 1.0 / (1.0 + ((1.0 - a) * (b + 1.0)))
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= -56000.0)
		tmp = 0.5;
	else
		tmp = Float64(1.0 / Float64(1.0 + Float64(Float64(1.0 - a) * Float64(b + 1.0))));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= -56000.0)
		tmp = 0.5;
	else
		tmp = 1.0 / (1.0 + ((1.0 - a) * (b + 1.0)));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, -56000.0], 0.5, N[(1.0 / N[(1.0 + N[(N[(1.0 - a), $MachinePrecision] * N[(b + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -56000:\\
\;\;\;\;0.5\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{1 + \left(1 - a\right) \cdot \left(b + 1\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < -56000

    1. Initial program 96.6%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity96.6%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*96.6%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div96.6%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg96.6%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/96.6%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity96.6%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative96.6%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in96.6%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg96.6%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse96.6%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in a around 0 98.4%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
    5. Taylor expanded in b around 0 18.5%

      \[\leadsto \color{blue}{0.5} \]

    if -56000 < b

    1. Initial program 99.5%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity99.5%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*99.5%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div99.5%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg99.4%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/99.4%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity99.4%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative99.4%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in62.9%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg62.9%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse99.5%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in b around 0 69.7%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    5. Step-by-step derivation
      1. distribute-rgt1-in80.9%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp80.9%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/80.9%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. +-commutative80.9%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{\left(1 + b\right)} \cdot 1}{e^{a}}} \]
      5. *-rgt-identity80.9%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    6. Simplified80.9%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    7. Taylor expanded in a around 0 53.2%

      \[\leadsto \frac{1}{1 + \color{blue}{\left(1 + \left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)\right)}} \]
    8. Step-by-step derivation
      1. associate-+r+53.2%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(\left(1 + b\right) + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
      2. associate-*r*53.2%

        \[\leadsto \frac{1}{1 + \left(\left(1 + b\right) + \color{blue}{\left(-1 \cdot a\right) \cdot \left(1 + b\right)}\right)} \]
      3. distribute-rgt1-in53.2%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(-1 \cdot a + 1\right) \cdot \left(1 + b\right)}} \]
      4. neg-mul-153.2%

        \[\leadsto \frac{1}{1 + \left(\color{blue}{\left(-a\right)} + 1\right) \cdot \left(1 + b\right)} \]
    9. Simplified53.2%

      \[\leadsto \frac{1}{1 + \color{blue}{\left(\left(-a\right) + 1\right) \cdot \left(1 + b\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification45.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -56000:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{1 + \left(1 - a\right) \cdot \left(b + 1\right)}\\ \end{array} \]

Alternative 9: 44.6% accurate, 33.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -2:\\ \;\;\;\;\frac{1}{a \cdot \left(-1 - b\right)}\\ \mathbf{else}:\\ \;\;\;\;0.5 + a \cdot 0.25\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= a -2.0) (/ 1.0 (* a (- -1.0 b))) (+ 0.5 (* a 0.25))))
double code(double a, double b) {
	double tmp;
	if (a <= -2.0) {
		tmp = 1.0 / (a * (-1.0 - b));
	} else {
		tmp = 0.5 + (a * 0.25);
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (a <= (-2.0d0)) then
        tmp = 1.0d0 / (a * ((-1.0d0) - b))
    else
        tmp = 0.5d0 + (a * 0.25d0)
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (a <= -2.0) {
		tmp = 1.0 / (a * (-1.0 - b));
	} else {
		tmp = 0.5 + (a * 0.25);
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if a <= -2.0:
		tmp = 1.0 / (a * (-1.0 - b))
	else:
		tmp = 0.5 + (a * 0.25)
	return tmp
function code(a, b)
	tmp = 0.0
	if (a <= -2.0)
		tmp = Float64(1.0 / Float64(a * Float64(-1.0 - b)));
	else
		tmp = Float64(0.5 + Float64(a * 0.25));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (a <= -2.0)
		tmp = 1.0 / (a * (-1.0 - b));
	else
		tmp = 0.5 + (a * 0.25);
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[a, -2.0], N[(1.0 / N[(a * N[(-1.0 - b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(0.5 + N[(a * 0.25), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \leq -2:\\
\;\;\;\;\frac{1}{a \cdot \left(-1 - b\right)}\\

\mathbf{else}:\\
\;\;\;\;0.5 + a \cdot 0.25\\


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

    1. Initial program 96.1%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity96.1%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*96.1%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div96.1%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg96.1%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/96.1%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity96.1%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative96.1%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in2.6%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg2.6%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse96.1%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in b around 0 67.6%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    5. Step-by-step derivation
      1. distribute-rgt1-in97.5%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp97.5%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/97.5%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. +-commutative97.5%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{\left(1 + b\right)} \cdot 1}{e^{a}}} \]
      5. *-rgt-identity97.5%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    6. Simplified97.5%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    7. Taylor expanded in a around 0 26.7%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
    8. Step-by-step derivation
      1. +-commutative26.7%

        \[\leadsto \frac{1}{\color{blue}{\left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right) + 2}} \]
      2. associate-+l+26.7%

        \[\leadsto \frac{1}{\color{blue}{b + \left(-1 \cdot \left(a \cdot \left(1 + b\right)\right) + 2\right)}} \]
      3. mul-1-neg26.7%

        \[\leadsto \frac{1}{b + \left(\color{blue}{\left(-a \cdot \left(1 + b\right)\right)} + 2\right)} \]
      4. distribute-rgt-neg-in26.7%

        \[\leadsto \frac{1}{b + \left(\color{blue}{a \cdot \left(-\left(1 + b\right)\right)} + 2\right)} \]
      5. neg-sub026.7%

        \[\leadsto \frac{1}{b + \left(a \cdot \color{blue}{\left(0 - \left(1 + b\right)\right)} + 2\right)} \]
      6. associate--r+26.7%

        \[\leadsto \frac{1}{b + \left(a \cdot \color{blue}{\left(\left(0 - 1\right) - b\right)} + 2\right)} \]
      7. metadata-eval26.7%

        \[\leadsto \frac{1}{b + \left(a \cdot \left(\color{blue}{-1} - b\right) + 2\right)} \]
    9. Simplified26.7%

      \[\leadsto \frac{1}{\color{blue}{b + \left(a \cdot \left(-1 - b\right) + 2\right)}} \]
    10. Taylor expanded in a around inf 26.7%

      \[\leadsto \frac{1}{\color{blue}{-1 \cdot \left(a \cdot \left(1 + b\right)\right)}} \]
    11. Step-by-step derivation
      1. +-commutative26.7%

        \[\leadsto \frac{1}{-1 \cdot \left(a \cdot \color{blue}{\left(b + 1\right)}\right)} \]
      2. distribute-lft-in26.7%

        \[\leadsto \frac{1}{-1 \cdot \color{blue}{\left(a \cdot b + a \cdot 1\right)}} \]
      3. *-rgt-identity26.7%

        \[\leadsto \frac{1}{-1 \cdot \left(a \cdot b + \color{blue}{a}\right)} \]
      4. distribute-lft-out26.7%

        \[\leadsto \frac{1}{\color{blue}{-1 \cdot \left(a \cdot b\right) + -1 \cdot a}} \]
      5. mul-1-neg26.7%

        \[\leadsto \frac{1}{\color{blue}{\left(-a \cdot b\right)} + -1 \cdot a} \]
      6. distribute-rgt-neg-out26.7%

        \[\leadsto \frac{1}{\color{blue}{a \cdot \left(-b\right)} + -1 \cdot a} \]
      7. *-commutative26.7%

        \[\leadsto \frac{1}{a \cdot \left(-b\right) + \color{blue}{a \cdot -1}} \]
      8. +-commutative26.7%

        \[\leadsto \frac{1}{\color{blue}{a \cdot -1 + a \cdot \left(-b\right)}} \]
      9. distribute-lft-out26.7%

        \[\leadsto \frac{1}{\color{blue}{a \cdot \left(-1 + \left(-b\right)\right)}} \]
      10. sub-neg26.7%

        \[\leadsto \frac{1}{a \cdot \color{blue}{\left(-1 - b\right)}} \]
    12. Simplified26.7%

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

    if -2 < a

    1. Initial program 100.0%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity100.0%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*100.0%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div100.0%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg100.0%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/100.0%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity100.0%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative100.0%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in100.0%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg100.0%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse100.0%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in b around 0 52.7%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
    5. Taylor expanded in a around 0 52.3%

      \[\leadsto \color{blue}{0.5 + 0.25 \cdot a} \]
    6. Step-by-step derivation
      1. *-commutative52.3%

        \[\leadsto 0.5 + \color{blue}{a \cdot 0.25} \]
    7. Simplified52.3%

      \[\leadsto \color{blue}{0.5 + a \cdot 0.25} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification44.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -2:\\ \;\;\;\;\frac{1}{a \cdot \left(-1 - b\right)}\\ \mathbf{else}:\\ \;\;\;\;0.5 + a \cdot 0.25\\ \end{array} \]

Alternative 10: 44.8% accurate, 33.7× speedup?

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

\\
\begin{array}{l}
\mathbf{if}\;b \leq 2:\\
\;\;\;\;\frac{1}{2 - a}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{b \cdot \left(1 - a\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < 2

    1. Initial program 98.4%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity98.4%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*98.3%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div98.3%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg98.3%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/98.3%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity98.3%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative98.3%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in76.7%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg76.7%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse98.3%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in b around 0 73.6%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
    5. Taylor expanded in a around 0 51.3%

      \[\leadsto \frac{1}{\color{blue}{2 + -1 \cdot a}} \]
    6. Step-by-step derivation
      1. neg-mul-151.3%

        \[\leadsto \frac{1}{2 + \color{blue}{\left(-a\right)}} \]
      2. unsub-neg51.3%

        \[\leadsto \frac{1}{\color{blue}{2 - a}} \]
    7. Simplified51.3%

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

    if 2 < b

    1. Initial program 100.0%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity100.0%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*100.0%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div100.0%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg100.0%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/100.0%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity100.0%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative100.0%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in54.9%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg54.9%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse100.0%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in b around 0 47.9%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    5. Step-by-step derivation
      1. distribute-rgt1-in47.9%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp47.9%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/47.9%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. +-commutative47.9%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{\left(1 + b\right)} \cdot 1}{e^{a}}} \]
      5. *-rgt-identity47.9%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    6. Simplified47.9%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    7. Taylor expanded in a around 0 28.1%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
    8. Step-by-step derivation
      1. +-commutative28.1%

        \[\leadsto \frac{1}{\color{blue}{\left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right) + 2}} \]
      2. associate-+l+28.1%

        \[\leadsto \frac{1}{\color{blue}{b + \left(-1 \cdot \left(a \cdot \left(1 + b\right)\right) + 2\right)}} \]
      3. mul-1-neg28.1%

        \[\leadsto \frac{1}{b + \left(\color{blue}{\left(-a \cdot \left(1 + b\right)\right)} + 2\right)} \]
      4. distribute-rgt-neg-in28.1%

        \[\leadsto \frac{1}{b + \left(\color{blue}{a \cdot \left(-\left(1 + b\right)\right)} + 2\right)} \]
      5. neg-sub028.1%

        \[\leadsto \frac{1}{b + \left(a \cdot \color{blue}{\left(0 - \left(1 + b\right)\right)} + 2\right)} \]
      6. associate--r+28.1%

        \[\leadsto \frac{1}{b + \left(a \cdot \color{blue}{\left(\left(0 - 1\right) - b\right)} + 2\right)} \]
      7. metadata-eval28.1%

        \[\leadsto \frac{1}{b + \left(a \cdot \left(\color{blue}{-1} - b\right) + 2\right)} \]
    9. Simplified28.1%

      \[\leadsto \frac{1}{\color{blue}{b + \left(a \cdot \left(-1 - b\right) + 2\right)}} \]
    10. Taylor expanded in b around inf 28.1%

      \[\leadsto \frac{1}{\color{blue}{b \cdot \left(1 + -1 \cdot a\right)}} \]
    11. Step-by-step derivation
      1. mul-1-neg28.1%

        \[\leadsto \frac{1}{b \cdot \left(1 + \color{blue}{\left(-a\right)}\right)} \]
      2. unsub-neg28.1%

        \[\leadsto \frac{1}{b \cdot \color{blue}{\left(1 - a\right)}} \]
    12. Simplified28.1%

      \[\leadsto \frac{1}{\color{blue}{b \cdot \left(1 - a\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification44.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 2:\\ \;\;\;\;\frac{1}{2 - a}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b \cdot \left(1 - a\right)}\\ \end{array} \]

Alternative 11: 44.2% accurate, 43.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -9.2:\\ \;\;\;\;\frac{-1}{b \cdot a}\\ \mathbf{else}:\\ \;\;\;\;0.5 + a \cdot 0.25\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= a -9.2) (/ -1.0 (* b a)) (+ 0.5 (* a 0.25))))
double code(double a, double b) {
	double tmp;
	if (a <= -9.2) {
		tmp = -1.0 / (b * a);
	} else {
		tmp = 0.5 + (a * 0.25);
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (a <= (-9.2d0)) then
        tmp = (-1.0d0) / (b * a)
    else
        tmp = 0.5d0 + (a * 0.25d0)
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (a <= -9.2) {
		tmp = -1.0 / (b * a);
	} else {
		tmp = 0.5 + (a * 0.25);
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if a <= -9.2:
		tmp = -1.0 / (b * a)
	else:
		tmp = 0.5 + (a * 0.25)
	return tmp
function code(a, b)
	tmp = 0.0
	if (a <= -9.2)
		tmp = Float64(-1.0 / Float64(b * a));
	else
		tmp = Float64(0.5 + Float64(a * 0.25));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (a <= -9.2)
		tmp = -1.0 / (b * a);
	else
		tmp = 0.5 + (a * 0.25);
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[a, -9.2], N[(-1.0 / N[(b * a), $MachinePrecision]), $MachinePrecision], N[(0.5 + N[(a * 0.25), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \leq -9.2:\\
\;\;\;\;\frac{-1}{b \cdot a}\\

\mathbf{else}:\\
\;\;\;\;0.5 + a \cdot 0.25\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if a < -9.1999999999999993

    1. Initial program 96.1%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity96.1%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*96.1%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div96.1%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg96.1%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/96.1%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity96.1%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative96.1%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in1.3%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg1.3%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse96.1%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in b around 0 67.2%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    5. Step-by-step derivation
      1. distribute-rgt1-in97.5%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp97.5%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/97.5%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. +-commutative97.5%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{\left(1 + b\right)} \cdot 1}{e^{a}}} \]
      5. *-rgt-identity97.5%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    6. Simplified97.5%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    7. Taylor expanded in a around 0 26.9%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
    8. Step-by-step derivation
      1. +-commutative26.9%

        \[\leadsto \frac{1}{\color{blue}{\left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right) + 2}} \]
      2. associate-+l+26.9%

        \[\leadsto \frac{1}{\color{blue}{b + \left(-1 \cdot \left(a \cdot \left(1 + b\right)\right) + 2\right)}} \]
      3. mul-1-neg26.9%

        \[\leadsto \frac{1}{b + \left(\color{blue}{\left(-a \cdot \left(1 + b\right)\right)} + 2\right)} \]
      4. distribute-rgt-neg-in26.9%

        \[\leadsto \frac{1}{b + \left(\color{blue}{a \cdot \left(-\left(1 + b\right)\right)} + 2\right)} \]
      5. neg-sub026.9%

        \[\leadsto \frac{1}{b + \left(a \cdot \color{blue}{\left(0 - \left(1 + b\right)\right)} + 2\right)} \]
      6. associate--r+26.9%

        \[\leadsto \frac{1}{b + \left(a \cdot \color{blue}{\left(\left(0 - 1\right) - b\right)} + 2\right)} \]
      7. metadata-eval26.9%

        \[\leadsto \frac{1}{b + \left(a \cdot \left(\color{blue}{-1} - b\right) + 2\right)} \]
    9. Simplified26.9%

      \[\leadsto \frac{1}{\color{blue}{b + \left(a \cdot \left(-1 - b\right) + 2\right)}} \]
    10. Taylor expanded in b around inf 25.7%

      \[\leadsto \frac{1}{\color{blue}{b \cdot \left(1 + -1 \cdot a\right)}} \]
    11. Step-by-step derivation
      1. mul-1-neg25.7%

        \[\leadsto \frac{1}{b \cdot \left(1 + \color{blue}{\left(-a\right)}\right)} \]
      2. unsub-neg25.7%

        \[\leadsto \frac{1}{b \cdot \color{blue}{\left(1 - a\right)}} \]
    12. Simplified25.7%

      \[\leadsto \frac{1}{\color{blue}{b \cdot \left(1 - a\right)}} \]
    13. Taylor expanded in a around inf 25.7%

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

    if -9.1999999999999993 < a

    1. Initial program 100.0%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity100.0%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*100.0%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div100.0%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg99.9%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/99.9%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity99.9%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative99.9%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in100.0%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg100.0%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse100.0%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in b around 0 53.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
    5. Taylor expanded in a around 0 52.0%

      \[\leadsto \color{blue}{0.5 + 0.25 \cdot a} \]
    6. Step-by-step derivation
      1. *-commutative52.0%

        \[\leadsto 0.5 + \color{blue}{a \cdot 0.25} \]
    7. Simplified52.0%

      \[\leadsto \color{blue}{0.5 + a \cdot 0.25} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification44.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -9.2:\\ \;\;\;\;\frac{-1}{b \cdot a}\\ \mathbf{else}:\\ \;\;\;\;0.5 + a \cdot 0.25\\ \end{array} \]

Alternative 12: 44.4% accurate, 43.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 7.5 \cdot 10^{+30}:\\ \;\;\;\;\frac{1}{2 - a}\\ \mathbf{else}:\\ \;\;\;\;\frac{-1}{b \cdot a}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b 7.5e+30) (/ 1.0 (- 2.0 a)) (/ -1.0 (* b a))))
double code(double a, double b) {
	double tmp;
	if (b <= 7.5e+30) {
		tmp = 1.0 / (2.0 - a);
	} else {
		tmp = -1.0 / (b * a);
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (b <= 7.5d+30) then
        tmp = 1.0d0 / (2.0d0 - a)
    else
        tmp = (-1.0d0) / (b * a)
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (b <= 7.5e+30) {
		tmp = 1.0 / (2.0 - a);
	} else {
		tmp = -1.0 / (b * a);
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= 7.5e+30:
		tmp = 1.0 / (2.0 - a)
	else:
		tmp = -1.0 / (b * a)
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= 7.5e+30)
		tmp = Float64(1.0 / Float64(2.0 - a));
	else
		tmp = Float64(-1.0 / Float64(b * a));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= 7.5e+30)
		tmp = 1.0 / (2.0 - a);
	else
		tmp = -1.0 / (b * a);
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, 7.5e+30], N[(1.0 / N[(2.0 - a), $MachinePrecision]), $MachinePrecision], N[(-1.0 / N[(b * a), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq 7.5 \cdot 10^{+30}:\\
\;\;\;\;\frac{1}{2 - a}\\

\mathbf{else}:\\
\;\;\;\;\frac{-1}{b \cdot a}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < 7.49999999999999973e30

    1. Initial program 98.4%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity98.4%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*98.4%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div98.4%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg98.4%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/98.4%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity98.4%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative98.4%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in76.6%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg76.7%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse98.4%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in b around 0 71.7%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
    5. Taylor expanded in a around 0 49.3%

      \[\leadsto \frac{1}{\color{blue}{2 + -1 \cdot a}} \]
    6. Step-by-step derivation
      1. neg-mul-149.3%

        \[\leadsto \frac{1}{2 + \color{blue}{\left(-a\right)}} \]
      2. unsub-neg49.3%

        \[\leadsto \frac{1}{\color{blue}{2 - a}} \]
    7. Simplified49.3%

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

    if 7.49999999999999973e30 < b

    1. Initial program 100.0%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity100.0%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-/l*100.0%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      3. remove-double-div100.0%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
      4. exp-neg100.0%

        \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
      5. associate-/r/100.0%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
      6. /-rgt-identity100.0%

        \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
      7. *-commutative100.0%

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
      8. distribute-rgt-in52.4%

        \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
      9. exp-neg52.4%

        \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
      10. rgt-mult-inverse100.0%

        \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
      11. prod-exp100.0%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
      12. unsub-neg100.0%

        \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Taylor expanded in b around 0 50.5%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    5. Step-by-step derivation
      1. distribute-rgt1-in50.5%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp50.5%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/50.5%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. +-commutative50.5%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{\left(1 + b\right)} \cdot 1}{e^{a}}} \]
      5. *-rgt-identity50.5%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    6. Simplified50.5%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    7. Taylor expanded in a around 0 31.2%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
    8. Step-by-step derivation
      1. +-commutative31.2%

        \[\leadsto \frac{1}{\color{blue}{\left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right) + 2}} \]
      2. associate-+l+31.2%

        \[\leadsto \frac{1}{\color{blue}{b + \left(-1 \cdot \left(a \cdot \left(1 + b\right)\right) + 2\right)}} \]
      3. mul-1-neg31.2%

        \[\leadsto \frac{1}{b + \left(\color{blue}{\left(-a \cdot \left(1 + b\right)\right)} + 2\right)} \]
      4. distribute-rgt-neg-in31.2%

        \[\leadsto \frac{1}{b + \left(\color{blue}{a \cdot \left(-\left(1 + b\right)\right)} + 2\right)} \]
      5. neg-sub031.2%

        \[\leadsto \frac{1}{b + \left(a \cdot \color{blue}{\left(0 - \left(1 + b\right)\right)} + 2\right)} \]
      6. associate--r+31.2%

        \[\leadsto \frac{1}{b + \left(a \cdot \color{blue}{\left(\left(0 - 1\right) - b\right)} + 2\right)} \]
      7. metadata-eval31.2%

        \[\leadsto \frac{1}{b + \left(a \cdot \left(\color{blue}{-1} - b\right) + 2\right)} \]
    9. Simplified31.2%

      \[\leadsto \frac{1}{\color{blue}{b + \left(a \cdot \left(-1 - b\right) + 2\right)}} \]
    10. Taylor expanded in b around inf 31.2%

      \[\leadsto \frac{1}{\color{blue}{b \cdot \left(1 + -1 \cdot a\right)}} \]
    11. Step-by-step derivation
      1. mul-1-neg31.2%

        \[\leadsto \frac{1}{b \cdot \left(1 + \color{blue}{\left(-a\right)}\right)} \]
      2. unsub-neg31.2%

        \[\leadsto \frac{1}{b \cdot \color{blue}{\left(1 - a\right)}} \]
    12. Simplified31.2%

      \[\leadsto \frac{1}{\color{blue}{b \cdot \left(1 - a\right)}} \]
    13. Taylor expanded in a around inf 30.0%

      \[\leadsto \color{blue}{\frac{-1}{a \cdot b}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification44.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 7.5 \cdot 10^{+30}:\\ \;\;\;\;\frac{1}{2 - a}\\ \mathbf{else}:\\ \;\;\;\;\frac{-1}{b \cdot a}\\ \end{array} \]

Alternative 13: 39.8% accurate, 61.0× speedup?

\[\begin{array}{l} \\ 0.5 + a \cdot 0.25 \end{array} \]
(FPCore (a b) :precision binary64 (+ 0.5 (* a 0.25)))
double code(double a, double b) {
	return 0.5 + (a * 0.25);
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = 0.5d0 + (a * 0.25d0)
end function
public static double code(double a, double b) {
	return 0.5 + (a * 0.25);
}
def code(a, b):
	return 0.5 + (a * 0.25)
function code(a, b)
	return Float64(0.5 + Float64(a * 0.25))
end
function tmp = code(a, b)
	tmp = 0.5 + (a * 0.25);
end
code[a_, b_] := N[(0.5 + N[(a * 0.25), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0.5 + a \cdot 0.25
\end{array}
Derivation
  1. Initial program 98.8%

    \[\frac{e^{a}}{e^{a} + e^{b}} \]
  2. Step-by-step derivation
    1. *-lft-identity98.8%

      \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
    2. associate-/l*98.8%

      \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
    3. remove-double-div98.8%

      \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
    4. exp-neg98.8%

      \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
    5. associate-/r/98.8%

      \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
    6. /-rgt-identity98.8%

      \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
    7. *-commutative98.8%

      \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
    8. distribute-rgt-in70.7%

      \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
    9. exp-neg70.7%

      \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
    10. rgt-mult-inverse98.8%

      \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
    11. prod-exp100.0%

      \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
    12. unsub-neg100.0%

      \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
  4. Taylor expanded in b around 0 66.2%

    \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
  5. Taylor expanded in a around 0 37.2%

    \[\leadsto \color{blue}{0.5 + 0.25 \cdot a} \]
  6. Step-by-step derivation
    1. *-commutative37.2%

      \[\leadsto 0.5 + \color{blue}{a \cdot 0.25} \]
  7. Simplified37.2%

    \[\leadsto \color{blue}{0.5 + a \cdot 0.25} \]
  8. Final simplification37.2%

    \[\leadsto 0.5 + a \cdot 0.25 \]

Alternative 14: 39.7% accurate, 305.0× 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. Step-by-step derivation
    1. *-lft-identity98.8%

      \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
    2. associate-/l*98.8%

      \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
    3. remove-double-div98.8%

      \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}} \]
    4. exp-neg98.8%

      \[\leadsto \frac{1}{\frac{e^{a} + e^{b}}{\frac{1}{\color{blue}{e^{-a}}}}} \]
    5. associate-/r/98.8%

      \[\leadsto \frac{1}{\color{blue}{\frac{e^{a} + e^{b}}{1} \cdot e^{-a}}} \]
    6. /-rgt-identity98.8%

      \[\leadsto \frac{1}{\color{blue}{\left(e^{a} + e^{b}\right)} \cdot e^{-a}} \]
    7. *-commutative98.8%

      \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot \left(e^{a} + e^{b}\right)}} \]
    8. distribute-rgt-in70.7%

      \[\leadsto \frac{1}{\color{blue}{e^{a} \cdot e^{-a} + e^{b} \cdot e^{-a}}} \]
    9. exp-neg70.7%

      \[\leadsto \frac{1}{e^{a} \cdot \color{blue}{\frac{1}{e^{a}}} + e^{b} \cdot e^{-a}} \]
    10. rgt-mult-inverse98.8%

      \[\leadsto \frac{1}{\color{blue}{1} + e^{b} \cdot e^{-a}} \]
    11. prod-exp100.0%

      \[\leadsto \frac{1}{1 + \color{blue}{e^{b + \left(-a\right)}}} \]
    12. unsub-neg100.0%

      \[\leadsto \frac{1}{1 + e^{\color{blue}{b - a}}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
  4. Taylor expanded in a around 0 82.7%

    \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
  5. Taylor expanded in b around 0 37.2%

    \[\leadsto \color{blue}{0.5} \]
  6. Final simplification37.2%

    \[\leadsto 0.5 \]

Developer target: 100.0% accurate, 2.9× 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 2023311 
(FPCore (a b)
  :name "Quotient of sum of exps"
  :precision binary64

  :herbie-target
  (/ 1.0 (+ 1.0 (exp (- b a))))

  (/ (exp a) (+ (exp a) (exp b))))