Quotient of sum of exps

Percentage Accurate: 98.7% → 100.0%
Time: 10.5s
Alternatives: 17
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 17 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: 98.7% 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 99.2%

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

      \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
    2. associate-*l/99.1%

      \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
    3. associate-/r/99.1%

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

      \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
    5. unsub-neg99.1%

      \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
    6. div-sub69.8%

      \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
    7. *-lft-identity69.8%

      \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
    8. associate-*l/69.8%

      \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
    9. lft-mult-inverse99.1%

      \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
    10. sub-neg99.1%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
    11. distribute-frac-neg99.1%

      \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
    12. remove-double-neg99.1%

      \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
    13. div-exp99.9%

      \[\leadsto \frac{1}{1 + \color{blue}{e^{b - a}}} \]
  3. Simplified99.9%

    \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. add-exp-log99.9%

      \[\leadsto \color{blue}{e^{\log \left(\frac{1}{1 + e^{b - a}}\right)}} \]
    2. log-rec99.9%

      \[\leadsto e^{\color{blue}{-\log \left(1 + e^{b - a}\right)}} \]
    3. log1p-define100.0%

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

    \[\leadsto \color{blue}{e^{-\mathsf{log1p}\left(e^{b - a}\right)}} \]
  7. Add Preprocessing

Alternative 2: 94.7% accurate, 2.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := a \cdot \left(-1 + a \cdot \left(0.5 + a \cdot -0.16666666666666666\right)\right)\\ \mathbf{if}\;a \leq -1 \cdot 10^{+103}:\\ \;\;\;\;\frac{1}{2 + t\_0}\\ \mathbf{elif}\;a \leq -6.8 \cdot 10^{+34}:\\ \;\;\;\;\frac{1}{2 + \left(b + b \cdot \left(t\_0 + \frac{t\_0}{b}\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{1 + e^{b}}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (let* ((t_0 (* a (+ -1.0 (* a (+ 0.5 (* a -0.16666666666666666)))))))
   (if (<= a -1e+103)
     (/ 1.0 (+ 2.0 t_0))
     (if (<= a -6.8e+34)
       (/ 1.0 (+ 2.0 (+ b (* b (+ t_0 (/ t_0 b))))))
       (/ 1.0 (+ 1.0 (exp b)))))))
double code(double a, double b) {
	double t_0 = a * (-1.0 + (a * (0.5 + (a * -0.16666666666666666))));
	double tmp;
	if (a <= -1e+103) {
		tmp = 1.0 / (2.0 + t_0);
	} else if (a <= -6.8e+34) {
		tmp = 1.0 / (2.0 + (b + (b * (t_0 + (t_0 / 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) :: t_0
    real(8) :: tmp
    t_0 = a * ((-1.0d0) + (a * (0.5d0 + (a * (-0.16666666666666666d0)))))
    if (a <= (-1d+103)) then
        tmp = 1.0d0 / (2.0d0 + t_0)
    else if (a <= (-6.8d+34)) then
        tmp = 1.0d0 / (2.0d0 + (b + (b * (t_0 + (t_0 / b)))))
    else
        tmp = 1.0d0 / (1.0d0 + exp(b))
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double t_0 = a * (-1.0 + (a * (0.5 + (a * -0.16666666666666666))));
	double tmp;
	if (a <= -1e+103) {
		tmp = 1.0 / (2.0 + t_0);
	} else if (a <= -6.8e+34) {
		tmp = 1.0 / (2.0 + (b + (b * (t_0 + (t_0 / b)))));
	} else {
		tmp = 1.0 / (1.0 + Math.exp(b));
	}
	return tmp;
}
def code(a, b):
	t_0 = a * (-1.0 + (a * (0.5 + (a * -0.16666666666666666))))
	tmp = 0
	if a <= -1e+103:
		tmp = 1.0 / (2.0 + t_0)
	elif a <= -6.8e+34:
		tmp = 1.0 / (2.0 + (b + (b * (t_0 + (t_0 / b)))))
	else:
		tmp = 1.0 / (1.0 + math.exp(b))
	return tmp
function code(a, b)
	t_0 = Float64(a * Float64(-1.0 + Float64(a * Float64(0.5 + Float64(a * -0.16666666666666666)))))
	tmp = 0.0
	if (a <= -1e+103)
		tmp = Float64(1.0 / Float64(2.0 + t_0));
	elseif (a <= -6.8e+34)
		tmp = Float64(1.0 / Float64(2.0 + Float64(b + Float64(b * Float64(t_0 + Float64(t_0 / b))))));
	else
		tmp = Float64(1.0 / Float64(1.0 + exp(b)));
	end
	return tmp
end
function tmp_2 = code(a, b)
	t_0 = a * (-1.0 + (a * (0.5 + (a * -0.16666666666666666))));
	tmp = 0.0;
	if (a <= -1e+103)
		tmp = 1.0 / (2.0 + t_0);
	elseif (a <= -6.8e+34)
		tmp = 1.0 / (2.0 + (b + (b * (t_0 + (t_0 / b)))));
	else
		tmp = 1.0 / (1.0 + exp(b));
	end
	tmp_2 = tmp;
end
code[a_, b_] := Block[{t$95$0 = N[(a * N[(-1.0 + N[(a * N[(0.5 + N[(a * -0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[a, -1e+103], N[(1.0 / N[(2.0 + t$95$0), $MachinePrecision]), $MachinePrecision], If[LessEqual[a, -6.8e+34], N[(1.0 / N[(2.0 + N[(b + N[(b * N[(t$95$0 + N[(t$95$0 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(1.0 + N[Exp[b], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := a \cdot \left(-1 + a \cdot \left(0.5 + a \cdot -0.16666666666666666\right)\right)\\
\mathbf{if}\;a \leq -1 \cdot 10^{+103}:\\
\;\;\;\;\frac{1}{2 + t\_0}\\

\mathbf{elif}\;a \leq -6.8 \cdot 10^{+34}:\\
\;\;\;\;\frac{1}{2 + \left(b + b \cdot \left(t\_0 + \frac{t\_0}{b}\right)\right)}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if a < -1e103

    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%

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

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

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

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub0.0%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity0.0%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/0.0%

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

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg100.0%

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

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

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

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

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in b around 0 100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
    6. Taylor expanded in a around 0 100.0%

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

    if -1e103 < a < -6.7999999999999999e34

    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%

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

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

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

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub0.0%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity0.0%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/0.0%

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

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg100.0%

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

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

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

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

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in b around 0 50.0%

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

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
    7. Simplified100.0%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(b + 1\right) \cdot e^{-a}}} \]
    8. Taylor expanded in a around 0 7.4%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + a \cdot \left(-1 \cdot \left(1 + b\right) + a \cdot \left(-0.16666666666666666 \cdot \left(a \cdot \left(1 + b\right)\right) + 0.5 \cdot \left(1 + b\right)\right)\right)\right)}} \]
    9. Taylor expanded in b around inf 66.3%

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

    if -6.7999999999999999e34 < a

    1. Initial program 98.9%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity98.9%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/98.9%

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

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

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg98.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub93.1%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity93.1%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/93.1%

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

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg98.8%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg98.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg98.8%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
      13. div-exp99.9%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b - a}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in a around 0 95.7%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification95.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -1 \cdot 10^{+103}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(-1 + a \cdot \left(0.5 + a \cdot -0.16666666666666666\right)\right)}\\ \mathbf{elif}\;a \leq -6.8 \cdot 10^{+34}:\\ \;\;\;\;\frac{1}{2 + \left(b + b \cdot \left(a \cdot \left(-1 + a \cdot \left(0.5 + a \cdot -0.16666666666666666\right)\right) + \frac{a \cdot \left(-1 + a \cdot \left(0.5 + a \cdot -0.16666666666666666\right)\right)}{b}\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{1 + e^{b}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 98.3% accurate, 2.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -4.6 \cdot 10^{-14}:\\ \;\;\;\;\frac{1}{1 + e^{-a}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{1 + e^{b}}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= a -4.6e-14) (/ 1.0 (+ 1.0 (exp (- a)))) (/ 1.0 (+ 1.0 (exp b)))))
double code(double a, double b) {
	double tmp;
	if (a <= -4.6e-14) {
		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 (a <= (-4.6d-14)) 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 (a <= -4.6e-14) {
		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 a <= -4.6e-14:
		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 (a <= -4.6e-14)
		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 (a <= -4.6e-14)
		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[a, -4.6e-14], 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}\;a \leq -4.6 \cdot 10^{-14}:\\
\;\;\;\;\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 a < -4.59999999999999996e-14

    1. Initial program 98.7%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity98.7%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/98.7%

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

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg98.7%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg98.7%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub6.1%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity6.1%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/6.1%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse98.7%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg98.7%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg98.7%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg98.7%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
      13. div-exp99.9%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b - a}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in b around 0 98.7%

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

    if -4.59999999999999996e-14 < 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/99.3%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/99.3%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg99.3%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg99.3%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub99.3%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity99.3%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/99.3%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse99.3%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg99.3%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg99.3%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg99.3%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
      13. div-exp99.9%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b - a}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in a around 0 99.7%

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

Alternative 4: 100.0% accurate, 2.8× speedup?

\[\begin{array}{l} \\ \frac{1}{-1 + \left(e^{b - a} + 2\right)} \end{array} \]
(FPCore (a b) :precision binary64 (/ 1.0 (+ -1.0 (+ (exp (- b a)) 2.0))))
double code(double a, double b) {
	return 1.0 / (-1.0 + (exp((b - a)) + 2.0));
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = 1.0d0 / ((-1.0d0) + (exp((b - a)) + 2.0d0))
end function
public static double code(double a, double b) {
	return 1.0 / (-1.0 + (Math.exp((b - a)) + 2.0));
}
def code(a, b):
	return 1.0 / (-1.0 + (math.exp((b - a)) + 2.0))
function code(a, b)
	return Float64(1.0 / Float64(-1.0 + Float64(exp(Float64(b - a)) + 2.0)))
end
function tmp = code(a, b)
	tmp = 1.0 / (-1.0 + (exp((b - a)) + 2.0));
end
code[a_, b_] := N[(1.0 / N[(-1.0 + N[(N[Exp[N[(b - a), $MachinePrecision]], $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{-1 + \left(e^{b - a} + 2\right)}
\end{array}
Derivation
  1. Initial program 99.2%

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

      \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
    2. associate-*l/99.1%

      \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
    3. associate-/r/99.1%

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

      \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
    5. unsub-neg99.1%

      \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
    6. div-sub69.8%

      \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
    7. *-lft-identity69.8%

      \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
    8. associate-*l/69.8%

      \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
    9. lft-mult-inverse99.1%

      \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
    10. sub-neg99.1%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
    11. distribute-frac-neg99.1%

      \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
    12. remove-double-neg99.1%

      \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
    13. div-exp99.9%

      \[\leadsto \frac{1}{1 + \color{blue}{e^{b - a}}} \]
  3. Simplified99.9%

    \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. expm1-log1p-u99.5%

      \[\leadsto \frac{1}{\color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(1 + e^{b - a}\right)\right)}} \]
    2. expm1-undefine99.5%

      \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{log1p}\left(1 + e^{b - a}\right)} - 1}} \]
  6. Applied egg-rr99.5%

    \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{log1p}\left(1 + e^{b - a}\right)} - 1}} \]
  7. Step-by-step derivation
    1. sub-neg99.5%

      \[\leadsto \frac{1}{\color{blue}{e^{\mathsf{log1p}\left(1 + e^{b - a}\right)} + \left(-1\right)}} \]
    2. metadata-eval99.5%

      \[\leadsto \frac{1}{e^{\mathsf{log1p}\left(1 + e^{b - a}\right)} + \color{blue}{-1}} \]
    3. +-commutative99.5%

      \[\leadsto \frac{1}{\color{blue}{-1 + e^{\mathsf{log1p}\left(1 + e^{b - a}\right)}}} \]
    4. log1p-undefine99.2%

      \[\leadsto \frac{1}{-1 + e^{\color{blue}{\log \left(1 + \left(1 + e^{b - a}\right)\right)}}} \]
    5. rem-exp-log99.9%

      \[\leadsto \frac{1}{-1 + \color{blue}{\left(1 + \left(1 + e^{b - a}\right)\right)}} \]
    6. associate-+r+99.9%

      \[\leadsto \frac{1}{-1 + \color{blue}{\left(\left(1 + 1\right) + e^{b - a}\right)}} \]
    7. metadata-eval99.9%

      \[\leadsto \frac{1}{-1 + \left(\color{blue}{2} + e^{b - a}\right)} \]
  8. Simplified99.9%

    \[\leadsto \frac{1}{\color{blue}{-1 + \left(2 + e^{b - a}\right)}} \]
  9. Final simplification99.9%

    \[\leadsto \frac{1}{-1 + \left(e^{b - a} + 2\right)} \]
  10. Add Preprocessing

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 99.2%

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

      \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
    2. associate-*l/99.1%

      \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
    3. associate-/r/99.1%

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

      \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
    5. unsub-neg99.1%

      \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
    6. div-sub69.8%

      \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
    7. *-lft-identity69.8%

      \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
    8. associate-*l/69.8%

      \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
    9. lft-mult-inverse99.1%

      \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
    10. sub-neg99.1%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
    11. distribute-frac-neg99.1%

      \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
    12. remove-double-neg99.1%

      \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
    13. div-exp99.9%

      \[\leadsto \frac{1}{1 + \color{blue}{e^{b - a}}} \]
  3. Simplified99.9%

    \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
  4. Add Preprocessing
  5. Final simplification99.9%

    \[\leadsto \frac{1}{e^{b - a} + 1} \]
  6. Add Preprocessing

Alternative 6: 87.1% accurate, 7.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -1.35:\\ \;\;\;\;1\\ \mathbf{elif}\;b \leq 9.8 \cdot 10^{+97}:\\ \;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(\left(-1 - b\right) + a \cdot \left(b \cdot \left(-0.16666666666666666 \cdot \left(a + \frac{a}{b}\right)\right) + 0.5 \cdot \left(b + 1\right)\right)\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b -1.35)
   1.0
   (if (<= b 9.8e+97)
     (/
      1.0
      (+
       2.0
       (+
        b
        (*
         a
         (+
          (- -1.0 b)
          (*
           a
           (+
            (* b (* -0.16666666666666666 (+ a (/ a b))))
            (* 0.5 (+ b 1.0)))))))))
     (/ 1.0 (+ 2.0 (* b (+ 1.0 (* b (+ 0.5 (* b 0.16666666666666666))))))))))
double code(double a, double b) {
	double tmp;
	if (b <= -1.35) {
		tmp = 1.0;
	} else if (b <= 9.8e+97) {
		tmp = 1.0 / (2.0 + (b + (a * ((-1.0 - b) + (a * ((b * (-0.16666666666666666 * (a + (a / b)))) + (0.5 * (b + 1.0))))))));
	} else {
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * (0.5 + (b * 0.16666666666666666))))));
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (b <= (-1.35d0)) then
        tmp = 1.0d0
    else if (b <= 9.8d+97) then
        tmp = 1.0d0 / (2.0d0 + (b + (a * (((-1.0d0) - b) + (a * ((b * ((-0.16666666666666666d0) * (a + (a / b)))) + (0.5d0 * (b + 1.0d0))))))))
    else
        tmp = 1.0d0 / (2.0d0 + (b * (1.0d0 + (b * (0.5d0 + (b * 0.16666666666666666d0))))))
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (b <= -1.35) {
		tmp = 1.0;
	} else if (b <= 9.8e+97) {
		tmp = 1.0 / (2.0 + (b + (a * ((-1.0 - b) + (a * ((b * (-0.16666666666666666 * (a + (a / b)))) + (0.5 * (b + 1.0))))))));
	} else {
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * (0.5 + (b * 0.16666666666666666))))));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= -1.35:
		tmp = 1.0
	elif b <= 9.8e+97:
		tmp = 1.0 / (2.0 + (b + (a * ((-1.0 - b) + (a * ((b * (-0.16666666666666666 * (a + (a / b)))) + (0.5 * (b + 1.0))))))))
	else:
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * (0.5 + (b * 0.16666666666666666))))))
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= -1.35)
		tmp = 1.0;
	elseif (b <= 9.8e+97)
		tmp = Float64(1.0 / Float64(2.0 + Float64(b + Float64(a * Float64(Float64(-1.0 - b) + Float64(a * Float64(Float64(b * Float64(-0.16666666666666666 * Float64(a + Float64(a / b)))) + Float64(0.5 * Float64(b + 1.0)))))))));
	else
		tmp = Float64(1.0 / Float64(2.0 + Float64(b * Float64(1.0 + Float64(b * Float64(0.5 + Float64(b * 0.16666666666666666)))))));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= -1.35)
		tmp = 1.0;
	elseif (b <= 9.8e+97)
		tmp = 1.0 / (2.0 + (b + (a * ((-1.0 - b) + (a * ((b * (-0.16666666666666666 * (a + (a / b)))) + (0.5 * (b + 1.0))))))));
	else
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * (0.5 + (b * 0.16666666666666666))))));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, -1.35], 1.0, If[LessEqual[b, 9.8e+97], N[(1.0 / N[(2.0 + N[(b + N[(a * N[(N[(-1.0 - b), $MachinePrecision] + N[(a * N[(N[(b * N[(-0.16666666666666666 * N[(a + N[(a / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[(b + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(2.0 + N[(b * N[(1.0 + N[(b * N[(0.5 + N[(b * 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -1.35:\\
\;\;\;\;1\\

\mathbf{elif}\;b \leq 9.8 \cdot 10^{+97}:\\
\;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(\left(-1 - b\right) + a \cdot \left(b \cdot \left(-0.16666666666666666 \cdot \left(a + \frac{a}{b}\right)\right) + 0.5 \cdot \left(b + 1\right)\right)\right)\right)}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if b < -1.3500000000000001

    1. Initial program 97.8%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity97.8%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/97.7%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/97.8%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg97.8%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub97.8%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/97.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse97.8%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg97.8%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg97.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg97.8%

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

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

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. 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-define100.0%

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

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

      \[\leadsto \color{blue}{\frac{\sqrt{e^{b + a} + 1}}{\sqrt{e^{b + a} + 1}}} \]
    8. Step-by-step derivation
      1. *-inverses100.0%

        \[\leadsto \color{blue}{1} \]
    9. Simplified100.0%

      \[\leadsto \color{blue}{1} \]

    if -1.3500000000000001 < b < 9.79999999999999928e97

    1. Initial program 99.2%

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

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/99.2%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/99.2%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg99.2%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg99.2%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub65.4%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity65.4%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/65.4%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse99.2%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg99.2%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg99.2%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg99.2%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
      13. div-exp99.9%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b - a}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in b around 0 75.0%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    6. Step-by-step derivation
      1. distribute-rgt1-in91.2%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
    7. Simplified91.2%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(b + 1\right) \cdot e^{-a}}} \]
    8. Taylor expanded in a around 0 78.4%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + a \cdot \left(-1 \cdot \left(1 + b\right) + a \cdot \left(-0.16666666666666666 \cdot \left(a \cdot \left(1 + b\right)\right) + 0.5 \cdot \left(1 + b\right)\right)\right)\right)}} \]
    9. Taylor expanded in b around inf 80.9%

      \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(-1 \cdot \left(1 + b\right) + a \cdot \left(\color{blue}{b \cdot \left(-0.16666666666666666 \cdot a + -0.16666666666666666 \cdot \frac{a}{b}\right)} + 0.5 \cdot \left(1 + b\right)\right)\right)\right)} \]
    10. Step-by-step derivation
      1. distribute-lft-out80.9%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(-1 \cdot \left(1 + b\right) + a \cdot \left(b \cdot \color{blue}{\left(-0.16666666666666666 \cdot \left(a + \frac{a}{b}\right)\right)} + 0.5 \cdot \left(1 + b\right)\right)\right)\right)} \]
    11. Simplified80.9%

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

    if 9.79999999999999928e97 < 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%

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

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

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

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub59.6%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity59.6%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/59.6%

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

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg100.0%

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

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

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

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

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in a around 0 100.0%

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

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + b \cdot \left(0.5 + 0.16666666666666666 \cdot b\right)\right)}} \]
    7. Step-by-step derivation
      1. *-commutative98.4%

        \[\leadsto \frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + \color{blue}{b \cdot 0.16666666666666666}\right)\right)} \]
    8. Simplified98.4%

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification88.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -1.35:\\ \;\;\;\;1\\ \mathbf{elif}\;b \leq 9.8 \cdot 10^{+97}:\\ \;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(\left(-1 - b\right) + a \cdot \left(b \cdot \left(-0.16666666666666666 \cdot \left(a + \frac{a}{b}\right)\right) + 0.5 \cdot \left(b + 1\right)\right)\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 86.1% accurate, 8.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -6.8:\\ \;\;\;\;1\\ \mathbf{elif}\;b \leq 9.8 \cdot 10^{+97}:\\ \;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(\left(-1 - b\right) + a \cdot \left(0.5 \cdot \left(b + 1\right) + -0.16666666666666666 \cdot \left(a \cdot \left(b + 1\right)\right)\right)\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b -6.8)
   1.0
   (if (<= b 9.8e+97)
     (/
      1.0
      (+
       2.0
       (+
        b
        (*
         a
         (+
          (- -1.0 b)
          (*
           a
           (+ (* 0.5 (+ b 1.0)) (* -0.16666666666666666 (* a (+ b 1.0))))))))))
     (/ 1.0 (+ 2.0 (* b (+ 1.0 (* b (+ 0.5 (* b 0.16666666666666666))))))))))
double code(double a, double b) {
	double tmp;
	if (b <= -6.8) {
		tmp = 1.0;
	} else if (b <= 9.8e+97) {
		tmp = 1.0 / (2.0 + (b + (a * ((-1.0 - b) + (a * ((0.5 * (b + 1.0)) + (-0.16666666666666666 * (a * (b + 1.0)))))))));
	} else {
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * (0.5 + (b * 0.16666666666666666))))));
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (b <= (-6.8d0)) then
        tmp = 1.0d0
    else if (b <= 9.8d+97) then
        tmp = 1.0d0 / (2.0d0 + (b + (a * (((-1.0d0) - b) + (a * ((0.5d0 * (b + 1.0d0)) + ((-0.16666666666666666d0) * (a * (b + 1.0d0)))))))))
    else
        tmp = 1.0d0 / (2.0d0 + (b * (1.0d0 + (b * (0.5d0 + (b * 0.16666666666666666d0))))))
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (b <= -6.8) {
		tmp = 1.0;
	} else if (b <= 9.8e+97) {
		tmp = 1.0 / (2.0 + (b + (a * ((-1.0 - b) + (a * ((0.5 * (b + 1.0)) + (-0.16666666666666666 * (a * (b + 1.0)))))))));
	} else {
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * (0.5 + (b * 0.16666666666666666))))));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= -6.8:
		tmp = 1.0
	elif b <= 9.8e+97:
		tmp = 1.0 / (2.0 + (b + (a * ((-1.0 - b) + (a * ((0.5 * (b + 1.0)) + (-0.16666666666666666 * (a * (b + 1.0)))))))))
	else:
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * (0.5 + (b * 0.16666666666666666))))))
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= -6.8)
		tmp = 1.0;
	elseif (b <= 9.8e+97)
		tmp = Float64(1.0 / Float64(2.0 + Float64(b + Float64(a * Float64(Float64(-1.0 - b) + Float64(a * Float64(Float64(0.5 * Float64(b + 1.0)) + Float64(-0.16666666666666666 * Float64(a * Float64(b + 1.0))))))))));
	else
		tmp = Float64(1.0 / Float64(2.0 + Float64(b * Float64(1.0 + Float64(b * Float64(0.5 + Float64(b * 0.16666666666666666)))))));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= -6.8)
		tmp = 1.0;
	elseif (b <= 9.8e+97)
		tmp = 1.0 / (2.0 + (b + (a * ((-1.0 - b) + (a * ((0.5 * (b + 1.0)) + (-0.16666666666666666 * (a * (b + 1.0)))))))));
	else
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * (0.5 + (b * 0.16666666666666666))))));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, -6.8], 1.0, If[LessEqual[b, 9.8e+97], N[(1.0 / N[(2.0 + N[(b + N[(a * N[(N[(-1.0 - b), $MachinePrecision] + N[(a * N[(N[(0.5 * N[(b + 1.0), $MachinePrecision]), $MachinePrecision] + N[(-0.16666666666666666 * N[(a * N[(b + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(2.0 + N[(b * N[(1.0 + N[(b * N[(0.5 + N[(b * 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -6.8:\\
\;\;\;\;1\\

\mathbf{elif}\;b \leq 9.8 \cdot 10^{+97}:\\
\;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(\left(-1 - b\right) + a \cdot \left(0.5 \cdot \left(b + 1\right) + -0.16666666666666666 \cdot \left(a \cdot \left(b + 1\right)\right)\right)\right)\right)}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if b < -6.79999999999999982

    1. Initial program 97.8%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity97.8%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/97.7%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/97.8%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg97.8%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub97.8%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/97.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse97.8%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg97.8%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg97.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg97.8%

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

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

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. 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-define100.0%

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

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

      \[\leadsto \color{blue}{\frac{\sqrt{e^{b + a} + 1}}{\sqrt{e^{b + a} + 1}}} \]
    8. Step-by-step derivation
      1. *-inverses100.0%

        \[\leadsto \color{blue}{1} \]
    9. Simplified100.0%

      \[\leadsto \color{blue}{1} \]

    if -6.79999999999999982 < b < 9.79999999999999928e97

    1. Initial program 99.2%

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

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/99.2%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/99.2%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg99.2%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg99.2%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub65.4%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity65.4%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/65.4%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse99.2%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg99.2%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg99.2%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg99.2%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
      13. div-exp99.9%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b - a}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in b around 0 75.0%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    6. Step-by-step derivation
      1. distribute-rgt1-in91.2%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
    7. Simplified91.2%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(b + 1\right) \cdot e^{-a}}} \]
    8. Taylor expanded in a around 0 78.4%

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

    if 9.79999999999999928e97 < 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%

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

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

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

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub59.6%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity59.6%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/59.6%

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

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg100.0%

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

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

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

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

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in a around 0 100.0%

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

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + b \cdot \left(0.5 + 0.16666666666666666 \cdot b\right)\right)}} \]
    7. Step-by-step derivation
      1. *-commutative98.4%

        \[\leadsto \frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + \color{blue}{b \cdot 0.16666666666666666}\right)\right)} \]
    8. Simplified98.4%

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification86.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -6.8:\\ \;\;\;\;1\\ \mathbf{elif}\;b \leq 9.8 \cdot 10^{+97}:\\ \;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(\left(-1 - b\right) + a \cdot \left(0.5 \cdot \left(b + 1\right) + -0.16666666666666666 \cdot \left(a \cdot \left(b + 1\right)\right)\right)\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 8: 83.8% accurate, 12.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -15.5:\\ \;\;\;\;1\\ \mathbf{elif}\;b \leq 1.2 \cdot 10^{-16}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(-1 + a \cdot \left(0.5 + a \cdot -0.16666666666666666\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b -15.5)
   1.0
   (if (<= b 1.2e-16)
     (/ 1.0 (+ 2.0 (* a (+ -1.0 (* a (+ 0.5 (* a -0.16666666666666666)))))))
     (/ 1.0 (+ 2.0 (* b (+ 1.0 (* b (+ 0.5 (* b 0.16666666666666666))))))))))
double code(double a, double b) {
	double tmp;
	if (b <= -15.5) {
		tmp = 1.0;
	} else if (b <= 1.2e-16) {
		tmp = 1.0 / (2.0 + (a * (-1.0 + (a * (0.5 + (a * -0.16666666666666666))))));
	} else {
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * (0.5 + (b * 0.16666666666666666))))));
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (b <= (-15.5d0)) then
        tmp = 1.0d0
    else if (b <= 1.2d-16) then
        tmp = 1.0d0 / (2.0d0 + (a * ((-1.0d0) + (a * (0.5d0 + (a * (-0.16666666666666666d0)))))))
    else
        tmp = 1.0d0 / (2.0d0 + (b * (1.0d0 + (b * (0.5d0 + (b * 0.16666666666666666d0))))))
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (b <= -15.5) {
		tmp = 1.0;
	} else if (b <= 1.2e-16) {
		tmp = 1.0 / (2.0 + (a * (-1.0 + (a * (0.5 + (a * -0.16666666666666666))))));
	} else {
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * (0.5 + (b * 0.16666666666666666))))));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= -15.5:
		tmp = 1.0
	elif b <= 1.2e-16:
		tmp = 1.0 / (2.0 + (a * (-1.0 + (a * (0.5 + (a * -0.16666666666666666))))))
	else:
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * (0.5 + (b * 0.16666666666666666))))))
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= -15.5)
		tmp = 1.0;
	elseif (b <= 1.2e-16)
		tmp = Float64(1.0 / Float64(2.0 + Float64(a * Float64(-1.0 + Float64(a * Float64(0.5 + Float64(a * -0.16666666666666666)))))));
	else
		tmp = Float64(1.0 / Float64(2.0 + Float64(b * Float64(1.0 + Float64(b * Float64(0.5 + Float64(b * 0.16666666666666666)))))));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= -15.5)
		tmp = 1.0;
	elseif (b <= 1.2e-16)
		tmp = 1.0 / (2.0 + (a * (-1.0 + (a * (0.5 + (a * -0.16666666666666666))))));
	else
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * (0.5 + (b * 0.16666666666666666))))));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, -15.5], 1.0, If[LessEqual[b, 1.2e-16], N[(1.0 / N[(2.0 + N[(a * N[(-1.0 + N[(a * N[(0.5 + N[(a * -0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(2.0 + N[(b * N[(1.0 + N[(b * N[(0.5 + N[(b * 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -15.5:\\
\;\;\;\;1\\

\mathbf{elif}\;b \leq 1.2 \cdot 10^{-16}:\\
\;\;\;\;\frac{1}{2 + a \cdot \left(-1 + a \cdot \left(0.5 + a \cdot -0.16666666666666666\right)\right)}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if b < -15.5

    1. Initial program 97.8%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity97.8%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/97.7%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/97.8%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg97.8%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub97.8%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/97.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse97.8%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg97.8%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg97.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg97.8%

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

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

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. 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-define100.0%

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

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

      \[\leadsto \color{blue}{\frac{\sqrt{e^{b + a} + 1}}{\sqrt{e^{b + a} + 1}}} \]
    8. Step-by-step derivation
      1. *-inverses100.0%

        \[\leadsto \color{blue}{1} \]
    9. Simplified100.0%

      \[\leadsto \color{blue}{1} \]

    if -15.5 < b < 1.20000000000000002e-16

    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/99.9%

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

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

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg99.9%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub63.1%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity63.1%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/63.1%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse99.9%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg99.9%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg99.9%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg99.9%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
      13. div-exp99.9%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b - a}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in b around 0 98.9%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
    6. Taylor expanded in a around 0 85.5%

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

    if 1.20000000000000002e-16 < b

    1. Initial program 98.6%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity98.6%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/98.6%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/98.6%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg98.6%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg98.6%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub65.2%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity65.2%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/65.2%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse98.6%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg98.6%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg98.6%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg98.6%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
      13. div-exp99.9%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b - a}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in a around 0 99.8%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
    6. Taylor expanded in b around 0 80.4%

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + b \cdot \left(0.5 + 0.16666666666666666 \cdot b\right)\right)}} \]
    7. Step-by-step derivation
      1. *-commutative80.4%

        \[\leadsto \frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + \color{blue}{b \cdot 0.16666666666666666}\right)\right)} \]
    8. Simplified80.4%

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification86.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -15.5:\\ \;\;\;\;1\\ \mathbf{elif}\;b \leq 1.2 \cdot 10^{-16}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(-1 + a \cdot \left(0.5 + a \cdot -0.16666666666666666\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 9: 82.2% accurate, 12.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -4.8:\\ \;\;\;\;1\\ \mathbf{elif}\;b \leq 1.15 \cdot 10^{+150}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(-1 + a \cdot \left(0.5 + a \cdot -0.16666666666666666\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot 0.5\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b -4.8)
   1.0
   (if (<= b 1.15e+150)
     (/ 1.0 (+ 2.0 (* a (+ -1.0 (* a (+ 0.5 (* a -0.16666666666666666)))))))
     (/ 1.0 (+ 2.0 (* b (+ 1.0 (* b 0.5))))))))
double code(double a, double b) {
	double tmp;
	if (b <= -4.8) {
		tmp = 1.0;
	} else if (b <= 1.15e+150) {
		tmp = 1.0 / (2.0 + (a * (-1.0 + (a * (0.5 + (a * -0.16666666666666666))))));
	} else {
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))));
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (b <= (-4.8d0)) then
        tmp = 1.0d0
    else if (b <= 1.15d+150) then
        tmp = 1.0d0 / (2.0d0 + (a * ((-1.0d0) + (a * (0.5d0 + (a * (-0.16666666666666666d0)))))))
    else
        tmp = 1.0d0 / (2.0d0 + (b * (1.0d0 + (b * 0.5d0))))
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (b <= -4.8) {
		tmp = 1.0;
	} else if (b <= 1.15e+150) {
		tmp = 1.0 / (2.0 + (a * (-1.0 + (a * (0.5 + (a * -0.16666666666666666))))));
	} else {
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= -4.8:
		tmp = 1.0
	elif b <= 1.15e+150:
		tmp = 1.0 / (2.0 + (a * (-1.0 + (a * (0.5 + (a * -0.16666666666666666))))))
	else:
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))))
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= -4.8)
		tmp = 1.0;
	elseif (b <= 1.15e+150)
		tmp = Float64(1.0 / Float64(2.0 + Float64(a * Float64(-1.0 + Float64(a * Float64(0.5 + Float64(a * -0.16666666666666666)))))));
	else
		tmp = Float64(1.0 / Float64(2.0 + Float64(b * Float64(1.0 + Float64(b * 0.5)))));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= -4.8)
		tmp = 1.0;
	elseif (b <= 1.15e+150)
		tmp = 1.0 / (2.0 + (a * (-1.0 + (a * (0.5 + (a * -0.16666666666666666))))));
	else
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, -4.8], 1.0, If[LessEqual[b, 1.15e+150], N[(1.0 / N[(2.0 + N[(a * N[(-1.0 + N[(a * N[(0.5 + N[(a * -0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(2.0 + N[(b * N[(1.0 + N[(b * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -4.8:\\
\;\;\;\;1\\

\mathbf{elif}\;b \leq 1.15 \cdot 10^{+150}:\\
\;\;\;\;\frac{1}{2 + a \cdot \left(-1 + a \cdot \left(0.5 + a \cdot -0.16666666666666666\right)\right)}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot 0.5\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if b < -4.79999999999999982

    1. Initial program 97.8%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity97.8%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/97.7%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/97.8%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg97.8%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub97.8%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/97.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse97.8%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg97.8%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg97.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg97.8%

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

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

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. 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-define100.0%

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

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

      \[\leadsto \color{blue}{\frac{\sqrt{e^{b + a} + 1}}{\sqrt{e^{b + a} + 1}}} \]
    8. Step-by-step derivation
      1. *-inverses100.0%

        \[\leadsto \color{blue}{1} \]
    9. Simplified100.0%

      \[\leadsto \color{blue}{1} \]

    if -4.79999999999999982 < b < 1.15000000000000001e150

    1. Initial program 99.3%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity99.3%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/99.3%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/99.3%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg99.3%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg99.3%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub64.8%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity64.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/64.8%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse99.3%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg99.3%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg99.3%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg99.3%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
      13. div-exp99.9%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b - a}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in b around 0 85.6%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
    6. Taylor expanded in a around 0 73.5%

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

    if 1.15000000000000001e150 < 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%

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

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

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

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub60.0%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity60.0%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/60.0%

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

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg100.0%

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

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

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

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

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in a around 0 100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
    6. Taylor expanded in b around 0 97.8%

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + 0.5 \cdot b\right)}} \]
    7. Step-by-step derivation
      1. *-commutative97.8%

        \[\leadsto \frac{1}{2 + b \cdot \left(1 + \color{blue}{b \cdot 0.5}\right)} \]
    8. Simplified97.8%

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + b \cdot 0.5\right)}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification82.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -4.8:\\ \;\;\;\;1\\ \mathbf{elif}\;b \leq 1.15 \cdot 10^{+150}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(-1 + a \cdot \left(0.5 + a \cdot -0.16666666666666666\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot 0.5\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 10: 78.6% accurate, 14.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -560:\\ \;\;\;\;1\\ \mathbf{elif}\;b \leq 1.15 \cdot 10^{+150}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(-1 + a \cdot 0.5\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot 0.5\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b -560.0)
   1.0
   (if (<= b 1.15e+150)
     (/ 1.0 (+ 2.0 (* a (+ -1.0 (* a 0.5)))))
     (/ 1.0 (+ 2.0 (* b (+ 1.0 (* b 0.5))))))))
double code(double a, double b) {
	double tmp;
	if (b <= -560.0) {
		tmp = 1.0;
	} else if (b <= 1.15e+150) {
		tmp = 1.0 / (2.0 + (a * (-1.0 + (a * 0.5))));
	} else {
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))));
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (b <= (-560.0d0)) then
        tmp = 1.0d0
    else if (b <= 1.15d+150) then
        tmp = 1.0d0 / (2.0d0 + (a * ((-1.0d0) + (a * 0.5d0))))
    else
        tmp = 1.0d0 / (2.0d0 + (b * (1.0d0 + (b * 0.5d0))))
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (b <= -560.0) {
		tmp = 1.0;
	} else if (b <= 1.15e+150) {
		tmp = 1.0 / (2.0 + (a * (-1.0 + (a * 0.5))));
	} else {
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= -560.0:
		tmp = 1.0
	elif b <= 1.15e+150:
		tmp = 1.0 / (2.0 + (a * (-1.0 + (a * 0.5))))
	else:
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))))
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= -560.0)
		tmp = 1.0;
	elseif (b <= 1.15e+150)
		tmp = Float64(1.0 / Float64(2.0 + Float64(a * Float64(-1.0 + Float64(a * 0.5)))));
	else
		tmp = Float64(1.0 / Float64(2.0 + Float64(b * Float64(1.0 + Float64(b * 0.5)))));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= -560.0)
		tmp = 1.0;
	elseif (b <= 1.15e+150)
		tmp = 1.0 / (2.0 + (a * (-1.0 + (a * 0.5))));
	else
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, -560.0], 1.0, If[LessEqual[b, 1.15e+150], N[(1.0 / N[(2.0 + N[(a * N[(-1.0 + N[(a * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(2.0 + N[(b * N[(1.0 + N[(b * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -560:\\
\;\;\;\;1\\

\mathbf{elif}\;b \leq 1.15 \cdot 10^{+150}:\\
\;\;\;\;\frac{1}{2 + a \cdot \left(-1 + a \cdot 0.5\right)}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot 0.5\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if b < -560

    1. Initial program 97.8%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity97.8%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/97.7%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/97.8%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg97.8%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub97.8%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/97.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse97.8%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg97.8%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg97.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg97.8%

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

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

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. 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-define100.0%

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

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

      \[\leadsto \color{blue}{\frac{\sqrt{e^{b + a} + 1}}{\sqrt{e^{b + a} + 1}}} \]
    8. Step-by-step derivation
      1. *-inverses100.0%

        \[\leadsto \color{blue}{1} \]
    9. Simplified100.0%

      \[\leadsto \color{blue}{1} \]

    if -560 < b < 1.15000000000000001e150

    1. Initial program 99.3%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity99.3%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/99.3%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/99.3%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg99.3%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg99.3%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub64.8%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity64.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/64.8%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse99.3%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg99.3%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg99.3%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg99.3%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
      13. div-exp99.9%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b - a}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in b around 0 85.6%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
    6. Taylor expanded in a around 0 70.1%

      \[\leadsto \frac{1}{\color{blue}{2 + a \cdot \left(0.5 \cdot a - 1\right)}} \]

    if 1.15000000000000001e150 < 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%

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

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

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

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub60.0%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity60.0%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/60.0%

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

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg100.0%

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

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

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

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

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in a around 0 100.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
    6. Taylor expanded in b around 0 97.8%

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + 0.5 \cdot b\right)}} \]
    7. Step-by-step derivation
      1. *-commutative97.8%

        \[\leadsto \frac{1}{2 + b \cdot \left(1 + \color{blue}{b \cdot 0.5}\right)} \]
    8. Simplified97.8%

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + b \cdot 0.5\right)}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification79.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -560:\\ \;\;\;\;1\\ \mathbf{elif}\;b \leq 1.15 \cdot 10^{+150}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(-1 + a \cdot 0.5\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot 0.5\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 11: 67.5% accurate, 19.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -6.5:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(-1 + a \cdot 0.5\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b -6.5) 1.0 (/ 1.0 (+ 2.0 (* a (+ -1.0 (* a 0.5)))))))
double code(double a, double b) {
	double tmp;
	if (b <= -6.5) {
		tmp = 1.0;
	} else {
		tmp = 1.0 / (2.0 + (a * (-1.0 + (a * 0.5))));
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (b <= (-6.5d0)) then
        tmp = 1.0d0
    else
        tmp = 1.0d0 / (2.0d0 + (a * ((-1.0d0) + (a * 0.5d0))))
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (b <= -6.5) {
		tmp = 1.0;
	} else {
		tmp = 1.0 / (2.0 + (a * (-1.0 + (a * 0.5))));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= -6.5:
		tmp = 1.0
	else:
		tmp = 1.0 / (2.0 + (a * (-1.0 + (a * 0.5))))
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= -6.5)
		tmp = 1.0;
	else
		tmp = Float64(1.0 / Float64(2.0 + Float64(a * Float64(-1.0 + Float64(a * 0.5)))));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= -6.5)
		tmp = 1.0;
	else
		tmp = 1.0 / (2.0 + (a * (-1.0 + (a * 0.5))));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, -6.5], 1.0, N[(1.0 / N[(2.0 + N[(a * N[(-1.0 + N[(a * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -6.5:\\
\;\;\;\;1\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{2 + a \cdot \left(-1 + a \cdot 0.5\right)}\\


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

    1. Initial program 97.8%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity97.8%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/97.7%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/97.8%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg97.8%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub97.8%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/97.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse97.8%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg97.8%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg97.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg97.8%

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

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

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. 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-define100.0%

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

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

      \[\leadsto \color{blue}{\frac{\sqrt{e^{b + a} + 1}}{\sqrt{e^{b + a} + 1}}} \]
    8. Step-by-step derivation
      1. *-inverses100.0%

        \[\leadsto \color{blue}{1} \]
    9. Simplified100.0%

      \[\leadsto \color{blue}{1} \]

    if -6.5 < b

    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%

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

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

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg99.4%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub63.9%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity63.9%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/63.9%

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

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

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg99.4%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg99.4%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
      13. div-exp99.9%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b - a}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in b around 0 77.3%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
    6. Taylor expanded in a around 0 60.7%

      \[\leadsto \frac{1}{\color{blue}{2 + a \cdot \left(0.5 \cdot a - 1\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification67.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -6.5:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(-1 + a \cdot 0.5\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 12: 54.5% accurate, 30.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -1.4:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 - a}\\ \end{array} \end{array} \]
(FPCore (a b) :precision binary64 (if (<= b -1.4) 1.0 (/ 1.0 (- 2.0 a))))
double code(double a, double b) {
	double tmp;
	if (b <= -1.4) {
		tmp = 1.0;
	} else {
		tmp = 1.0 / (2.0 - a);
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (b <= (-1.4d0)) then
        tmp = 1.0d0
    else
        tmp = 1.0d0 / (2.0d0 - a)
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (b <= -1.4) {
		tmp = 1.0;
	} else {
		tmp = 1.0 / (2.0 - a);
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= -1.4:
		tmp = 1.0
	else:
		tmp = 1.0 / (2.0 - a)
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= -1.4)
		tmp = 1.0;
	else
		tmp = Float64(1.0 / Float64(2.0 - a));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= -1.4)
		tmp = 1.0;
	else
		tmp = 1.0 / (2.0 - a);
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, -1.4], 1.0, N[(1.0 / N[(2.0 - a), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -1.4:\\
\;\;\;\;1\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{2 - a}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < -1.3999999999999999

    1. Initial program 97.8%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity97.8%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/97.7%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/97.8%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg97.8%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub97.8%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/97.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse97.8%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg97.8%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg97.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg97.8%

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

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

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. 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-define100.0%

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

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

      \[\leadsto \color{blue}{\frac{\sqrt{e^{b + a} + 1}}{\sqrt{e^{b + a} + 1}}} \]
    8. Step-by-step derivation
      1. *-inverses100.0%

        \[\leadsto \color{blue}{1} \]
    9. Simplified100.0%

      \[\leadsto \color{blue}{1} \]

    if -1.3999999999999999 < b

    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%

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

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

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg99.4%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub63.9%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity63.9%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/63.9%

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

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

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg99.4%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg99.4%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
      13. div-exp99.9%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b - a}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in b around 0 77.3%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
    6. Taylor expanded in a around 0 43.6%

      \[\leadsto \frac{1}{\color{blue}{2 + -1 \cdot a}} \]
    7. Step-by-step derivation
      1. neg-mul-143.6%

        \[\leadsto \frac{1}{2 + \color{blue}{\left(-a\right)}} \]
      2. unsub-neg43.6%

        \[\leadsto \frac{1}{\color{blue}{2 - a}} \]
    8. Simplified43.6%

      \[\leadsto \frac{1}{\color{blue}{2 - a}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 13: 54.6% accurate, 30.5× speedup?

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

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

\mathbf{else}:\\
\;\;\;\;\frac{1}{b + 2}\\


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

    1. Initial program 97.8%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity97.8%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/97.7%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/97.8%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg97.8%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub97.8%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/97.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse97.8%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg97.8%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg97.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg97.8%

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

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

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. 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-define100.0%

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

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

      \[\leadsto \color{blue}{\frac{\sqrt{e^{b + a} + 1}}{\sqrt{e^{b + a} + 1}}} \]
    8. Step-by-step derivation
      1. *-inverses100.0%

        \[\leadsto \color{blue}{1} \]
    9. Simplified100.0%

      \[\leadsto \color{blue}{1} \]

    if -1 < b

    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%

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

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

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg99.4%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub63.9%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity63.9%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/63.9%

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

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

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg99.4%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg99.4%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
      13. div-exp99.9%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b - a}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in a around 0 76.4%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
    6. Taylor expanded in b around 0 43.2%

      \[\leadsto \frac{1}{\color{blue}{2 + b}} \]
    7. Step-by-step derivation
      1. +-commutative43.2%

        \[\leadsto \frac{1}{\color{blue}{b + 2}} \]
    8. Simplified43.2%

      \[\leadsto \frac{1}{\color{blue}{b + 2}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 14: 53.8% accurate, 30.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -1.8:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;0.5 + b \cdot -0.25\\ \end{array} \end{array} \]
(FPCore (a b) :precision binary64 (if (<= b -1.8) 1.0 (+ 0.5 (* b -0.25))))
double code(double a, double b) {
	double tmp;
	if (b <= -1.8) {
		tmp = 1.0;
	} else {
		tmp = 0.5 + (b * -0.25);
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (b <= (-1.8d0)) then
        tmp = 1.0d0
    else
        tmp = 0.5d0 + (b * (-0.25d0))
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (b <= -1.8) {
		tmp = 1.0;
	} else {
		tmp = 0.5 + (b * -0.25);
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= -1.8:
		tmp = 1.0
	else:
		tmp = 0.5 + (b * -0.25)
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= -1.8)
		tmp = 1.0;
	else
		tmp = Float64(0.5 + Float64(b * -0.25));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= -1.8)
		tmp = 1.0;
	else
		tmp = 0.5 + (b * -0.25);
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, -1.8], 1.0, N[(0.5 + N[(b * -0.25), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -1.8:\\
\;\;\;\;1\\

\mathbf{else}:\\
\;\;\;\;0.5 + b \cdot -0.25\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < -1.80000000000000004

    1. Initial program 97.8%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity97.8%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/97.7%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/97.8%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg97.8%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub97.8%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/97.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse97.8%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg97.8%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg97.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg97.8%

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

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

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. 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-define100.0%

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

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

      \[\leadsto \color{blue}{\frac{\sqrt{e^{b + a} + 1}}{\sqrt{e^{b + a} + 1}}} \]
    8. Step-by-step derivation
      1. *-inverses100.0%

        \[\leadsto \color{blue}{1} \]
    9. Simplified100.0%

      \[\leadsto \color{blue}{1} \]

    if -1.80000000000000004 < b

    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%

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

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

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg99.4%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub63.9%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity63.9%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/63.9%

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

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

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg99.4%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg99.4%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
      13. div-exp99.9%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b - a}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in a around 0 76.4%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
    6. Taylor expanded in b around 0 42.6%

      \[\leadsto \color{blue}{0.5 + -0.25 \cdot b} \]
    7. Step-by-step derivation
      1. *-commutative42.6%

        \[\leadsto 0.5 + \color{blue}{b \cdot -0.25} \]
    8. Simplified42.6%

      \[\leadsto \color{blue}{0.5 + b \cdot -0.25} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 15: 53.8% accurate, 30.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -0.98:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;0.5 + a \cdot 0.25\\ \end{array} \end{array} \]
(FPCore (a b) :precision binary64 (if (<= b -0.98) 1.0 (+ 0.5 (* a 0.25))))
double code(double a, double b) {
	double tmp;
	if (b <= -0.98) {
		tmp = 1.0;
	} 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 (b <= (-0.98d0)) then
        tmp = 1.0d0
    else
        tmp = 0.5d0 + (a * 0.25d0)
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (b <= -0.98) {
		tmp = 1.0;
	} else {
		tmp = 0.5 + (a * 0.25);
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= -0.98:
		tmp = 1.0
	else:
		tmp = 0.5 + (a * 0.25)
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= -0.98)
		tmp = 1.0;
	else
		tmp = Float64(0.5 + Float64(a * 0.25));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= -0.98)
		tmp = 1.0;
	else
		tmp = 0.5 + (a * 0.25);
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, -0.98], 1.0, N[(0.5 + N[(a * 0.25), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -0.98:\\
\;\;\;\;1\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < -0.97999999999999998

    1. Initial program 97.8%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity97.8%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/97.7%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/97.8%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg97.8%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub97.8%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/97.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse97.8%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg97.8%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg97.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg97.8%

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

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

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. 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-define100.0%

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

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

      \[\leadsto \color{blue}{\frac{\sqrt{e^{b + a} + 1}}{\sqrt{e^{b + a} + 1}}} \]
    8. Step-by-step derivation
      1. *-inverses100.0%

        \[\leadsto \color{blue}{1} \]
    9. Simplified100.0%

      \[\leadsto \color{blue}{1} \]

    if -0.97999999999999998 < b

    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%

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

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

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg99.4%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub63.9%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity63.9%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/63.9%

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

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

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg99.4%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg99.4%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
      13. div-exp99.9%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b - a}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in b around 0 77.3%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
    6. Taylor expanded in a around 0 42.6%

      \[\leadsto \color{blue}{0.5 + 0.25 \cdot a} \]
    7. Step-by-step derivation
      1. *-commutative42.6%

        \[\leadsto 0.5 + \color{blue}{a \cdot 0.25} \]
    8. Simplified42.6%

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

Alternative 16: 53.6% accurate, 50.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -1.1:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \end{array} \]
(FPCore (a b) :precision binary64 (if (<= b -1.1) 1.0 0.5))
double code(double a, double b) {
	double tmp;
	if (b <= -1.1) {
		tmp = 1.0;
	} else {
		tmp = 0.5;
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (b <= (-1.1d0)) then
        tmp = 1.0d0
    else
        tmp = 0.5d0
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (b <= -1.1) {
		tmp = 1.0;
	} else {
		tmp = 0.5;
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= -1.1:
		tmp = 1.0
	else:
		tmp = 0.5
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= -1.1)
		tmp = 1.0;
	else
		tmp = 0.5;
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= -1.1)
		tmp = 1.0;
	else
		tmp = 0.5;
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, -1.1], 1.0, 0.5]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -1.1:\\
\;\;\;\;1\\

\mathbf{else}:\\
\;\;\;\;0.5\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < -1.1000000000000001

    1. Initial program 97.8%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity97.8%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/97.7%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/97.8%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg97.8%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub97.8%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity97.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/97.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse97.8%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg97.8%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg97.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg97.8%

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

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

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. 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-define100.0%

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

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

      \[\leadsto \color{blue}{\frac{\sqrt{e^{b + a} + 1}}{\sqrt{e^{b + a} + 1}}} \]
    8. Step-by-step derivation
      1. *-inverses100.0%

        \[\leadsto \color{blue}{1} \]
    9. Simplified100.0%

      \[\leadsto \color{blue}{1} \]

    if -1.1000000000000001 < b

    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%

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

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

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg99.4%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub63.9%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity63.9%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/63.9%

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

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

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg99.4%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg99.4%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
      13. div-exp99.9%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{b - a}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
    4. Add Preprocessing
    5. Taylor expanded in a around 0 76.4%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
    6. Taylor expanded in b around 0 41.9%

      \[\leadsto \color{blue}{0.5} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 17: 38.6% 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 99.2%

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

      \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
    2. associate-*l/99.1%

      \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
    3. associate-/r/99.1%

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

      \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
    5. unsub-neg99.1%

      \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
    6. div-sub69.8%

      \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
    7. *-lft-identity69.8%

      \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
    8. associate-*l/69.8%

      \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
    9. lft-mult-inverse99.1%

      \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
    10. sub-neg99.1%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
    11. distribute-frac-neg99.1%

      \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
    12. remove-double-neg99.1%

      \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
    13. div-exp99.9%

      \[\leadsto \frac{1}{1 + \color{blue}{e^{b - a}}} \]
  3. Simplified99.9%

    \[\leadsto \color{blue}{\frac{1}{1 + e^{b - a}}} \]
  4. Add Preprocessing
  5. Taylor expanded in a around 0 80.5%

    \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
  6. Taylor expanded in b around 0 37.8%

    \[\leadsto \color{blue}{0.5} \]
  7. Add Preprocessing

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 2024100 
(FPCore (a b)
  :name "Quotient of sum of exps"
  :precision binary64

  :alt
  (/ 1.0 (+ 1.0 (exp (- b a))))

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