Quotient of sum of exps

Percentage Accurate: 99.1% → 100.0%
Time: 8.9s
Alternatives: 13
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 13 alternatives:

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

Initial Program: 99.1% accurate, 1.0× speedup?

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

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

Alternative 1: 100.0% accurate, 1.0× speedup?

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

\\
e^{-\mathsf{log1p}\left(e^{b - a}\right)}
\end{array}
Derivation
  1. Initial program 98.0%

    \[\frac{e^{a}}{e^{a} + e^{b}} \]
  2. Step-by-step derivation
    1. *-lft-identity98.0%

      \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
    2. associate-*l/98.0%

      \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
    3. associate-/r/98.0%

      \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
    4. metadata-eval98.0%

      \[\leadsto \frac{\color{blue}{--1}}{\frac{e^{a} + e^{b}}{e^{a}}} \]
    5. *-rgt-identity98.0%

      \[\leadsto \frac{--1}{\frac{\color{blue}{\left(e^{a} + e^{b}\right) \cdot 1}}{e^{a}}} \]
    6. associate-*r/98.0%

      \[\leadsto \frac{--1}{\color{blue}{\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}}} \]
    7. exp-neg98.0%

      \[\leadsto \frac{--1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{-a}}} \]
    8. distribute-neg-frac98.0%

      \[\leadsto \color{blue}{-\frac{-1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
    9. distribute-frac-neg298.0%

      \[\leadsto \color{blue}{\frac{-1}{-\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
    10. distribute-lft-neg-out98.0%

      \[\leadsto \frac{-1}{\color{blue}{\left(-\left(e^{a} + e^{b}\right)\right) \cdot e^{-a}}} \]
    11. +-commutative98.0%

      \[\leadsto \frac{-1}{\left(-\color{blue}{\left(e^{b} + e^{a}\right)}\right) \cdot e^{-a}} \]
    12. distribute-neg-in98.0%

      \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) + \left(-e^{a}\right)\right)} \cdot e^{-a}} \]
    13. sub-neg98.0%

      \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) - e^{a}\right)} \cdot e^{-a}} \]
    14. *-commutative98.0%

      \[\leadsto \frac{-1}{\color{blue}{e^{-a} \cdot \left(\left(-e^{b}\right) - e^{a}\right)}} \]
    15. sub-neg98.0%

      \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(\left(-e^{b}\right) + \left(-e^{a}\right)\right)}} \]
    16. distribute-neg-in98.0%

      \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(-\left(e^{b} + e^{a}\right)\right)}} \]
    17. +-commutative98.0%

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

    \[\leadsto \color{blue}{\frac{-1}{-1 - \frac{e^{b}}{e^{a}}}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. add-exp-log99.2%

      \[\leadsto \color{blue}{e^{\log \left(\frac{-1}{-1 - \frac{e^{b}}{e^{a}}}\right)}} \]
    2. log-div0.0%

      \[\leadsto e^{\color{blue}{\log -1 - \log \left(-1 - \frac{e^{b}}{e^{a}}\right)}} \]
    3. sub-neg0.0%

      \[\leadsto e^{\log -1 - \log \color{blue}{\left(-1 + \left(-\frac{e^{b}}{e^{a}}\right)\right)}} \]
    4. metadata-eval0.0%

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

      \[\leadsto e^{\log -1 - \log \color{blue}{\left(-\left(1 + \frac{e^{b}}{e^{a}}\right)\right)}} \]
    6. div-exp0.0%

      \[\leadsto e^{\log -1 - \log \left(-\left(1 + \color{blue}{e^{b - a}}\right)\right)} \]
    7. log-div100.0%

      \[\leadsto e^{\color{blue}{\log \left(\frac{-1}{-\left(1 + e^{b - a}\right)}\right)}} \]
    8. metadata-eval100.0%

      \[\leadsto e^{\log \left(\frac{\color{blue}{-1}}{-\left(1 + e^{b - a}\right)}\right)} \]
    9. frac-2neg100.0%

      \[\leadsto e^{\log \color{blue}{\left(\frac{1}{1 + e^{b - a}}\right)}} \]
    10. div-exp99.2%

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

      \[\leadsto e^{\color{blue}{-\log \left(1 + \frac{e^{b}}{e^{a}}\right)}} \]
    12. log1p-define99.2%

      \[\leadsto e^{-\color{blue}{\mathsf{log1p}\left(\frac{e^{b}}{e^{a}}\right)}} \]
    13. div-exp100.0%

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

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

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

Alternative 2: 98.1% accurate, 2.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -88000000:\\ \;\;\;\;\frac{e^{a}}{a + 2}\\ \mathbf{elif}\;a \leq 1.75 \cdot 10^{-15}:\\ \;\;\;\;\frac{1}{1 + e^{b}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{1 + e^{-a}}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= a -88000000.0)
   (/ (exp a) (+ a 2.0))
   (if (<= a 1.75e-15) (/ 1.0 (+ 1.0 (exp b))) (/ 1.0 (+ 1.0 (exp (- a)))))))
double code(double a, double b) {
	double tmp;
	if (a <= -88000000.0) {
		tmp = exp(a) / (a + 2.0);
	} else if (a <= 1.75e-15) {
		tmp = 1.0 / (1.0 + exp(b));
	} else {
		tmp = 1.0 / (1.0 + exp(-a));
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (a <= (-88000000.0d0)) then
        tmp = exp(a) / (a + 2.0d0)
    else if (a <= 1.75d-15) then
        tmp = 1.0d0 / (1.0d0 + exp(b))
    else
        tmp = 1.0d0 / (1.0d0 + exp(-a))
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (a <= -88000000.0) {
		tmp = Math.exp(a) / (a + 2.0);
	} else if (a <= 1.75e-15) {
		tmp = 1.0 / (1.0 + Math.exp(b));
	} else {
		tmp = 1.0 / (1.0 + Math.exp(-a));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if a <= -88000000.0:
		tmp = math.exp(a) / (a + 2.0)
	elif a <= 1.75e-15:
		tmp = 1.0 / (1.0 + math.exp(b))
	else:
		tmp = 1.0 / (1.0 + math.exp(-a))
	return tmp
function code(a, b)
	tmp = 0.0
	if (a <= -88000000.0)
		tmp = Float64(exp(a) / Float64(a + 2.0));
	elseif (a <= 1.75e-15)
		tmp = Float64(1.0 / Float64(1.0 + exp(b)));
	else
		tmp = Float64(1.0 / Float64(1.0 + exp(Float64(-a))));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (a <= -88000000.0)
		tmp = exp(a) / (a + 2.0);
	elseif (a <= 1.75e-15)
		tmp = 1.0 / (1.0 + exp(b));
	else
		tmp = 1.0 / (1.0 + exp(-a));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[a, -88000000.0], N[(N[Exp[a], $MachinePrecision] / N[(a + 2.0), $MachinePrecision]), $MachinePrecision], If[LessEqual[a, 1.75e-15], N[(1.0 / N[(1.0 + N[Exp[b], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(1.0 + N[Exp[(-a)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \leq -88000000:\\
\;\;\;\;\frac{e^{a}}{a + 2}\\

\mathbf{elif}\;a \leq 1.75 \cdot 10^{-15}:\\
\;\;\;\;\frac{1}{1 + e^{b}}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if a < -8.8e7

    1. Initial program 98.4%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Add Preprocessing
    3. Taylor expanded in b around 0 100.0%

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

      \[\leadsto \frac{e^{a}}{\color{blue}{2 + a}} \]
    5. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \frac{e^{a}}{\color{blue}{a + 2}} \]
    6. Simplified100.0%

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

    if -8.8e7 < a < 1.75e-15

    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. metadata-eval99.4%

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

        \[\leadsto \frac{--1}{\frac{\color{blue}{\left(e^{a} + e^{b}\right) \cdot 1}}{e^{a}}} \]
      6. associate-*r/99.4%

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

        \[\leadsto \frac{--1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{-a}}} \]
      8. distribute-neg-frac99.4%

        \[\leadsto \color{blue}{-\frac{-1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      9. distribute-frac-neg299.4%

        \[\leadsto \color{blue}{\frac{-1}{-\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      10. distribute-lft-neg-out99.4%

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

        \[\leadsto \frac{-1}{\left(-\color{blue}{\left(e^{b} + e^{a}\right)}\right) \cdot e^{-a}} \]
      12. distribute-neg-in99.4%

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

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

        \[\leadsto \frac{-1}{\color{blue}{e^{-a} \cdot \left(\left(-e^{b}\right) - e^{a}\right)}} \]
      15. sub-neg99.4%

        \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(\left(-e^{b}\right) + \left(-e^{a}\right)\right)}} \]
      16. distribute-neg-in99.4%

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

        \[\leadsto \frac{-1}{e^{-a} \cdot \left(-\color{blue}{\left(e^{a} + e^{b}\right)}\right)} \]
    3. Simplified99.4%

      \[\leadsto \color{blue}{\frac{-1}{-1 - \frac{e^{b}}{e^{a}}}} \]
    4. Add Preprocessing
    5. Taylor expanded in a around 0 99.2%

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

    if 1.75e-15 < a

    1. Initial program 66.7%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity66.7%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/66.7%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/66.7%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. metadata-eval66.7%

        \[\leadsto \frac{\color{blue}{--1}}{\frac{e^{a} + e^{b}}{e^{a}}} \]
      5. *-rgt-identity66.7%

        \[\leadsto \frac{--1}{\frac{\color{blue}{\left(e^{a} + e^{b}\right) \cdot 1}}{e^{a}}} \]
      6. associate-*r/66.7%

        \[\leadsto \frac{--1}{\color{blue}{\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}}} \]
      7. exp-neg66.5%

        \[\leadsto \frac{--1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{-a}}} \]
      8. distribute-neg-frac66.5%

        \[\leadsto \color{blue}{-\frac{-1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      9. distribute-frac-neg266.5%

        \[\leadsto \color{blue}{\frac{-1}{-\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      10. distribute-lft-neg-out66.5%

        \[\leadsto \frac{-1}{\color{blue}{\left(-\left(e^{a} + e^{b}\right)\right) \cdot e^{-a}}} \]
      11. +-commutative66.5%

        \[\leadsto \frac{-1}{\left(-\color{blue}{\left(e^{b} + e^{a}\right)}\right) \cdot e^{-a}} \]
      12. distribute-neg-in66.5%

        \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) + \left(-e^{a}\right)\right)} \cdot e^{-a}} \]
      13. sub-neg66.5%

        \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) - e^{a}\right)} \cdot e^{-a}} \]
      14. *-commutative66.5%

        \[\leadsto \frac{-1}{\color{blue}{e^{-a} \cdot \left(\left(-e^{b}\right) - e^{a}\right)}} \]
      15. sub-neg66.5%

        \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(\left(-e^{b}\right) + \left(-e^{a}\right)\right)}} \]
      16. distribute-neg-in66.5%

        \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(-\left(e^{b} + e^{a}\right)\right)}} \]
      17. +-commutative66.5%

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

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

      \[\leadsto \color{blue}{\frac{1}{1 + \frac{1}{e^{a}}}} \]
    6. Step-by-step derivation
      1. rec-exp99.8%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{-a}}} \]
    7. Simplified99.8%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -88000000:\\ \;\;\;\;\frac{e^{a}}{a + 2}\\ \mathbf{elif}\;a \leq 1.75 \cdot 10^{-15}:\\ \;\;\;\;\frac{1}{1 + e^{b}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{1 + e^{-a}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 92.7% accurate, 2.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -3.3 \cdot 10^{+95}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(a \cdot \left(0.5 + a \cdot -0.16666666666666666\right) + -1\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{1 + e^{b}}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= a -3.3e+95)
   (/ 1.0 (+ 2.0 (* a (+ (* a (+ 0.5 (* a -0.16666666666666666))) -1.0))))
   (/ 1.0 (+ 1.0 (exp b)))))
double code(double a, double b) {
	double tmp;
	if (a <= -3.3e+95) {
		tmp = 1.0 / (2.0 + (a * ((a * (0.5 + (a * -0.16666666666666666))) + -1.0)));
	} 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 <= (-3.3d+95)) then
        tmp = 1.0d0 / (2.0d0 + (a * ((a * (0.5d0 + (a * (-0.16666666666666666d0)))) + (-1.0d0))))
    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 <= -3.3e+95) {
		tmp = 1.0 / (2.0 + (a * ((a * (0.5 + (a * -0.16666666666666666))) + -1.0)));
	} else {
		tmp = 1.0 / (1.0 + Math.exp(b));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if a <= -3.3e+95:
		tmp = 1.0 / (2.0 + (a * ((a * (0.5 + (a * -0.16666666666666666))) + -1.0)))
	else:
		tmp = 1.0 / (1.0 + math.exp(b))
	return tmp
function code(a, b)
	tmp = 0.0
	if (a <= -3.3e+95)
		tmp = Float64(1.0 / Float64(2.0 + Float64(a * Float64(Float64(a * Float64(0.5 + Float64(a * -0.16666666666666666))) + -1.0))));
	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 <= -3.3e+95)
		tmp = 1.0 / (2.0 + (a * ((a * (0.5 + (a * -0.16666666666666666))) + -1.0)));
	else
		tmp = 1.0 / (1.0 + exp(b));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[a, -3.3e+95], N[(1.0 / N[(2.0 + N[(a * N[(N[(a * N[(0.5 + N[(a * -0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $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 -3.3 \cdot 10^{+95}:\\
\;\;\;\;\frac{1}{2 + a \cdot \left(a \cdot \left(0.5 + a \cdot -0.16666666666666666\right) + -1\right)}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if a < -3.2999999999999998e95

    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. metadata-eval100.0%

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

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

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

        \[\leadsto \frac{--1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{-a}}} \]
      8. distribute-neg-frac100.0%

        \[\leadsto \color{blue}{-\frac{-1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      9. distribute-frac-neg2100.0%

        \[\leadsto \color{blue}{\frac{-1}{-\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      10. distribute-lft-neg-out100.0%

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

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

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

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

        \[\leadsto \frac{-1}{\color{blue}{e^{-a} \cdot \left(\left(-e^{b}\right) - e^{a}\right)}} \]
      15. sub-neg100.0%

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

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

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

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

      \[\leadsto \color{blue}{\frac{1}{1 + \frac{1}{e^{a}}}} \]
    6. Step-by-step derivation
      1. rec-exp100.0%

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

      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
    8. Taylor expanded in a around 0 98.1%

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

    if -3.2999999999999998e95 < a

    1. Initial program 97.6%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity97.6%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/97.6%

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

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. metadata-eval97.5%

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

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

        \[\leadsto \frac{--1}{\color{blue}{\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}}} \]
      7. exp-neg97.6%

        \[\leadsto \frac{--1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{-a}}} \]
      8. distribute-neg-frac97.6%

        \[\leadsto \color{blue}{-\frac{-1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      9. distribute-frac-neg297.6%

        \[\leadsto \color{blue}{\frac{-1}{-\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      10. distribute-lft-neg-out97.6%

        \[\leadsto \frac{-1}{\color{blue}{\left(-\left(e^{a} + e^{b}\right)\right) \cdot e^{-a}}} \]
      11. +-commutative97.6%

        \[\leadsto \frac{-1}{\left(-\color{blue}{\left(e^{b} + e^{a}\right)}\right) \cdot e^{-a}} \]
      12. distribute-neg-in97.6%

        \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) + \left(-e^{a}\right)\right)} \cdot e^{-a}} \]
      13. sub-neg97.6%

        \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) - e^{a}\right)} \cdot e^{-a}} \]
      14. *-commutative97.6%

        \[\leadsto \frac{-1}{\color{blue}{e^{-a} \cdot \left(\left(-e^{b}\right) - e^{a}\right)}} \]
      15. sub-neg97.6%

        \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(\left(-e^{b}\right) + \left(-e^{a}\right)\right)}} \]
      16. distribute-neg-in97.6%

        \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(-\left(e^{b} + e^{a}\right)\right)}} \]
      17. +-commutative97.6%

        \[\leadsto \frac{-1}{e^{-a} \cdot \left(-\color{blue}{\left(e^{a} + e^{b}\right)}\right)} \]
    3. Simplified99.0%

      \[\leadsto \color{blue}{\frac{-1}{-1 - \frac{e^{b}}{e^{a}}}} \]
    4. Add Preprocessing
    5. Taylor expanded in a around 0 92.1%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification93.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -3.3 \cdot 10^{+95}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(a \cdot \left(0.5 + a \cdot -0.16666666666666666\right) + -1\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{1 + e^{b}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 98.3% accurate, 2.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -88000000:\\ \;\;\;\;\frac{e^{a}}{a + 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{1 + e^{b}}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= a -88000000.0) (/ (exp a) (+ a 2.0)) (/ 1.0 (+ 1.0 (exp b)))))
double code(double a, double b) {
	double tmp;
	if (a <= -88000000.0) {
		tmp = exp(a) / (a + 2.0);
	} 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 <= (-88000000.0d0)) then
        tmp = exp(a) / (a + 2.0d0)
    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 <= -88000000.0) {
		tmp = Math.exp(a) / (a + 2.0);
	} else {
		tmp = 1.0 / (1.0 + Math.exp(b));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if a <= -88000000.0:
		tmp = math.exp(a) / (a + 2.0)
	else:
		tmp = 1.0 / (1.0 + math.exp(b))
	return tmp
function code(a, b)
	tmp = 0.0
	if (a <= -88000000.0)
		tmp = Float64(exp(a) / Float64(a + 2.0));
	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 <= -88000000.0)
		tmp = exp(a) / (a + 2.0);
	else
		tmp = 1.0 / (1.0 + exp(b));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[a, -88000000.0], N[(N[Exp[a], $MachinePrecision] / N[(a + 2.0), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(1.0 + N[Exp[b], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \leq -88000000:\\
\;\;\;\;\frac{e^{a}}{a + 2}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if a < -8.8e7

    1. Initial program 98.4%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Add Preprocessing
    3. Taylor expanded in b around 0 100.0%

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

      \[\leadsto \frac{e^{a}}{\color{blue}{2 + a}} \]
    5. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \frac{e^{a}}{\color{blue}{a + 2}} \]
    6. Simplified100.0%

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

    if -8.8e7 < a

    1. Initial program 97.9%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity97.9%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/97.9%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/97.9%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. metadata-eval97.9%

        \[\leadsto \frac{\color{blue}{--1}}{\frac{e^{a} + e^{b}}{e^{a}}} \]
      5. *-rgt-identity97.9%

        \[\leadsto \frac{--1}{\frac{\color{blue}{\left(e^{a} + e^{b}\right) \cdot 1}}{e^{a}}} \]
      6. associate-*r/97.9%

        \[\leadsto \frac{--1}{\color{blue}{\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}}} \]
      7. exp-neg97.9%

        \[\leadsto \frac{--1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{-a}}} \]
      8. distribute-neg-frac97.9%

        \[\leadsto \color{blue}{-\frac{-1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      9. distribute-frac-neg297.9%

        \[\leadsto \color{blue}{\frac{-1}{-\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      10. distribute-lft-neg-out97.9%

        \[\leadsto \frac{-1}{\color{blue}{\left(-\left(e^{a} + e^{b}\right)\right) \cdot e^{-a}}} \]
      11. +-commutative97.9%

        \[\leadsto \frac{-1}{\left(-\color{blue}{\left(e^{b} + e^{a}\right)}\right) \cdot e^{-a}} \]
      12. distribute-neg-in97.9%

        \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) + \left(-e^{a}\right)\right)} \cdot e^{-a}} \]
      13. sub-neg97.9%

        \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) - e^{a}\right)} \cdot e^{-a}} \]
      14. *-commutative97.9%

        \[\leadsto \frac{-1}{\color{blue}{e^{-a} \cdot \left(\left(-e^{b}\right) - e^{a}\right)}} \]
      15. sub-neg97.9%

        \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(\left(-e^{b}\right) + \left(-e^{a}\right)\right)}} \]
      16. distribute-neg-in97.9%

        \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(-\left(e^{b} + e^{a}\right)\right)}} \]
      17. +-commutative97.9%

        \[\leadsto \frac{-1}{e^{-a} \cdot \left(-\color{blue}{\left(e^{a} + e^{b}\right)}\right)} \]
    3. Simplified99.4%

      \[\leadsto \color{blue}{\frac{-1}{-1 - \frac{e^{b}}{e^{a}}}} \]
    4. Add Preprocessing
    5. Taylor expanded in a around 0 97.0%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification97.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -88000000:\\ \;\;\;\;\frac{e^{a}}{a + 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{1 + e^{b}}\\ \end{array} \]
  5. 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 98.0%

    \[\frac{e^{a}}{e^{a} + e^{b}} \]
  2. Step-by-step derivation
    1. *-lft-identity98.0%

      \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
    2. associate-*l/98.0%

      \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
    3. associate-/r/98.0%

      \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
    4. remove-double-neg98.0%

      \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
    5. unsub-neg98.0%

      \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
    6. div-sub73.0%

      \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
    7. *-lft-identity73.0%

      \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
    8. associate-*l/73.0%

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

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

Alternative 6: 67.8% accurate, 15.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 1.4 \cdot 10^{+154}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(a \cdot \left(0.5 + a \cdot -0.16666666666666666\right) + -1\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot 0.5\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b 1.4e+154)
   (/ 1.0 (+ 2.0 (* a (+ (* a (+ 0.5 (* a -0.16666666666666666))) -1.0))))
   (/ 1.0 (+ 2.0 (* b (+ 1.0 (* b 0.5)))))))
double code(double a, double b) {
	double tmp;
	if (b <= 1.4e+154) {
		tmp = 1.0 / (2.0 + (a * ((a * (0.5 + (a * -0.16666666666666666))) + -1.0)));
	} 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 <= 1.4d+154) then
        tmp = 1.0d0 / (2.0d0 + (a * ((a * (0.5d0 + (a * (-0.16666666666666666d0)))) + (-1.0d0))))
    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 <= 1.4e+154) {
		tmp = 1.0 / (2.0 + (a * ((a * (0.5 + (a * -0.16666666666666666))) + -1.0)));
	} else {
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= 1.4e+154:
		tmp = 1.0 / (2.0 + (a * ((a * (0.5 + (a * -0.16666666666666666))) + -1.0)))
	else:
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))))
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= 1.4e+154)
		tmp = Float64(1.0 / Float64(2.0 + Float64(a * Float64(Float64(a * Float64(0.5 + Float64(a * -0.16666666666666666))) + -1.0))));
	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 <= 1.4e+154)
		tmp = 1.0 / (2.0 + (a * ((a * (0.5 + (a * -0.16666666666666666))) + -1.0)));
	else
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, 1.4e+154], N[(1.0 / N[(2.0 + N[(a * N[(N[(a * N[(0.5 + N[(a * -0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -1.0), $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 1.4 \cdot 10^{+154}:\\
\;\;\;\;\frac{1}{2 + a \cdot \left(a \cdot \left(0.5 + a \cdot -0.16666666666666666\right) + -1\right)}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < 1.4e154

    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/97.8%

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

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. metadata-eval97.8%

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

        \[\leadsto \frac{--1}{\frac{\color{blue}{\left(e^{a} + e^{b}\right) \cdot 1}}{e^{a}}} \]
      6. associate-*r/97.8%

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

        \[\leadsto \frac{--1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{-a}}} \]
      8. distribute-neg-frac97.8%

        \[\leadsto \color{blue}{-\frac{-1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      9. distribute-frac-neg297.8%

        \[\leadsto \color{blue}{\frac{-1}{-\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      10. distribute-lft-neg-out97.8%

        \[\leadsto \frac{-1}{\color{blue}{\left(-\left(e^{a} + e^{b}\right)\right) \cdot e^{-a}}} \]
      11. +-commutative97.8%

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

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

        \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) - e^{a}\right)} \cdot e^{-a}} \]
      14. *-commutative97.8%

        \[\leadsto \frac{-1}{\color{blue}{e^{-a} \cdot \left(\left(-e^{b}\right) - e^{a}\right)}} \]
      15. sub-neg97.8%

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

        \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(-\left(e^{b} + e^{a}\right)\right)}} \]
      17. +-commutative97.8%

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

      \[\leadsto \color{blue}{\frac{-1}{-1 - \frac{e^{b}}{e^{a}}}} \]
    4. Add Preprocessing
    5. Taylor expanded in b around 0 74.5%

      \[\leadsto \color{blue}{\frac{1}{1 + \frac{1}{e^{a}}}} \]
    6. Step-by-step derivation
      1. rec-exp74.5%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{-a}}} \]
    7. Simplified74.5%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
    8. Taylor expanded in a around 0 66.0%

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

    if 1.4e154 < 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. metadata-eval100.0%

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

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

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

        \[\leadsto \frac{--1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{-a}}} \]
      8. distribute-neg-frac100.0%

        \[\leadsto \color{blue}{-\frac{-1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      9. distribute-frac-neg2100.0%

        \[\leadsto \color{blue}{\frac{-1}{-\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      10. distribute-lft-neg-out100.0%

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

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

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

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

        \[\leadsto \frac{-1}{\color{blue}{e^{-a} \cdot \left(\left(-e^{b}\right) - e^{a}\right)}} \]
      15. sub-neg100.0%

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

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

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

      \[\leadsto \color{blue}{\frac{-1}{-1 - \frac{e^{b}}{e^{a}}}} \]
    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 0 100.0%

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + 0.5 \cdot b\right)}} \]
    7. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto \frac{1}{2 + b \cdot \left(1 + \color{blue}{b \cdot 0.5}\right)} \]
    8. Simplified100.0%

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + b \cdot 0.5\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification69.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 1.4 \cdot 10^{+154}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(a \cdot \left(0.5 + a \cdot -0.16666666666666666\right) + -1\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot 0.5\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 71.2% accurate, 15.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 1.05 \cdot 10^{+103}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(a \cdot \left(0.5 + a \cdot -0.16666666666666666\right) + -1\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b 1.05e+103)
   (/ 1.0 (+ 2.0 (* a (+ (* a (+ 0.5 (* a -0.16666666666666666))) -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 <= 1.05e+103) {
		tmp = 1.0 / (2.0 + (a * ((a * (0.5 + (a * -0.16666666666666666))) + -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 <= 1.05d+103) then
        tmp = 1.0d0 / (2.0d0 + (a * ((a * (0.5d0 + (a * (-0.16666666666666666d0)))) + (-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 <= 1.05e+103) {
		tmp = 1.0 / (2.0 + (a * ((a * (0.5 + (a * -0.16666666666666666))) + -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 <= 1.05e+103:
		tmp = 1.0 / (2.0 + (a * ((a * (0.5 + (a * -0.16666666666666666))) + -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 <= 1.05e+103)
		tmp = Float64(1.0 / Float64(2.0 + Float64(a * Float64(Float64(a * Float64(0.5 + Float64(a * -0.16666666666666666))) + -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 <= 1.05e+103)
		tmp = 1.0 / (2.0 + (a * ((a * (0.5 + (a * -0.16666666666666666))) + -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, 1.05e+103], N[(1.0 / N[(2.0 + N[(a * N[(N[(a * N[(0.5 + N[(a * -0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -1.0), $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 1.05 \cdot 10^{+103}:\\
\;\;\;\;\frac{1}{2 + a \cdot \left(a \cdot \left(0.5 + a \cdot -0.16666666666666666\right) + -1\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 2 regimes
  2. if b < 1.0500000000000001e103

    1. Initial program 97.7%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity97.7%

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

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

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. metadata-eval97.7%

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

        \[\leadsto \frac{--1}{\frac{\color{blue}{\left(e^{a} + e^{b}\right) \cdot 1}}{e^{a}}} \]
      6. associate-*r/97.7%

        \[\leadsto \frac{--1}{\color{blue}{\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}}} \]
      7. exp-neg97.7%

        \[\leadsto \frac{--1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{-a}}} \]
      8. distribute-neg-frac97.7%

        \[\leadsto \color{blue}{-\frac{-1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      9. distribute-frac-neg297.7%

        \[\leadsto \color{blue}{\frac{-1}{-\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      10. distribute-lft-neg-out97.7%

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

        \[\leadsto \frac{-1}{\left(-\color{blue}{\left(e^{b} + e^{a}\right)}\right) \cdot e^{-a}} \]
      12. distribute-neg-in97.7%

        \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) + \left(-e^{a}\right)\right)} \cdot e^{-a}} \]
      13. sub-neg97.7%

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

        \[\leadsto \frac{-1}{\color{blue}{e^{-a} \cdot \left(\left(-e^{b}\right) - e^{a}\right)}} \]
      15. sub-neg97.7%

        \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(\left(-e^{b}\right) + \left(-e^{a}\right)\right)}} \]
      16. distribute-neg-in97.7%

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

        \[\leadsto \frac{-1}{e^{-a} \cdot \left(-\color{blue}{\left(e^{a} + e^{b}\right)}\right)} \]
    3. Simplified99.0%

      \[\leadsto \color{blue}{\frac{-1}{-1 - \frac{e^{b}}{e^{a}}}} \]
    4. Add Preprocessing
    5. Taylor expanded in b around 0 76.3%

      \[\leadsto \color{blue}{\frac{1}{1 + \frac{1}{e^{a}}}} \]
    6. Step-by-step derivation
      1. rec-exp76.3%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{-a}}} \]
    7. Simplified76.3%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
    8. Taylor expanded in a around 0 67.8%

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

    if 1.0500000000000001e103 < 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. metadata-eval100.0%

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

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

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

        \[\leadsto \frac{--1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{-a}}} \]
      8. distribute-neg-frac100.0%

        \[\leadsto \color{blue}{-\frac{-1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      9. distribute-frac-neg2100.0%

        \[\leadsto \color{blue}{\frac{-1}{-\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      10. distribute-lft-neg-out100.0%

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

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

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

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

        \[\leadsto \frac{-1}{\color{blue}{e^{-a} \cdot \left(\left(-e^{b}\right) - e^{a}\right)}} \]
      15. sub-neg100.0%

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

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

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

      \[\leadsto \color{blue}{\frac{-1}{-1 - \frac{e^{b}}{e^{a}}}} \]
    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 0 100.0%

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + b \cdot \left(0.5 + 0.16666666666666666 \cdot b\right)\right)}} \]
    7. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto \frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + \color{blue}{b \cdot 0.16666666666666666}\right)\right)} \]
    8. Simplified100.0%

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification72.6%

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

Alternative 8: 64.3% accurate, 19.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 4.7 \cdot 10^{+153}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(a \cdot 0.5 + -1\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot 0.5\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b 4.7e+153)
   (/ 1.0 (+ 2.0 (* a (+ (* a 0.5) -1.0))))
   (/ 1.0 (+ 2.0 (* b (+ 1.0 (* b 0.5)))))))
double code(double a, double b) {
	double tmp;
	if (b <= 4.7e+153) {
		tmp = 1.0 / (2.0 + (a * ((a * 0.5) + -1.0)));
	} 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 <= 4.7d+153) then
        tmp = 1.0d0 / (2.0d0 + (a * ((a * 0.5d0) + (-1.0d0))))
    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 <= 4.7e+153) {
		tmp = 1.0 / (2.0 + (a * ((a * 0.5) + -1.0)));
	} else {
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= 4.7e+153:
		tmp = 1.0 / (2.0 + (a * ((a * 0.5) + -1.0)))
	else:
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))))
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= 4.7e+153)
		tmp = Float64(1.0 / Float64(2.0 + Float64(a * Float64(Float64(a * 0.5) + -1.0))));
	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 <= 4.7e+153)
		tmp = 1.0 / (2.0 + (a * ((a * 0.5) + -1.0)));
	else
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, 4.7e+153], N[(1.0 / N[(2.0 + N[(a * N[(N[(a * 0.5), $MachinePrecision] + -1.0), $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 4.7 \cdot 10^{+153}:\\
\;\;\;\;\frac{1}{2 + a \cdot \left(a \cdot 0.5 + -1\right)}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < 4.69999999999999968e153

    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/97.8%

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

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. metadata-eval97.8%

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

        \[\leadsto \frac{--1}{\frac{\color{blue}{\left(e^{a} + e^{b}\right) \cdot 1}}{e^{a}}} \]
      6. associate-*r/97.8%

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

        \[\leadsto \frac{--1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{-a}}} \]
      8. distribute-neg-frac97.8%

        \[\leadsto \color{blue}{-\frac{-1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      9. distribute-frac-neg297.8%

        \[\leadsto \color{blue}{\frac{-1}{-\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      10. distribute-lft-neg-out97.8%

        \[\leadsto \frac{-1}{\color{blue}{\left(-\left(e^{a} + e^{b}\right)\right) \cdot e^{-a}}} \]
      11. +-commutative97.8%

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

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

        \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) - e^{a}\right)} \cdot e^{-a}} \]
      14. *-commutative97.8%

        \[\leadsto \frac{-1}{\color{blue}{e^{-a} \cdot \left(\left(-e^{b}\right) - e^{a}\right)}} \]
      15. sub-neg97.8%

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

        \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(-\left(e^{b} + e^{a}\right)\right)}} \]
      17. +-commutative97.8%

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

      \[\leadsto \color{blue}{\frac{-1}{-1 - \frac{e^{b}}{e^{a}}}} \]
    4. Add Preprocessing
    5. Taylor expanded in b around 0 74.5%

      \[\leadsto \color{blue}{\frac{1}{1 + \frac{1}{e^{a}}}} \]
    6. Step-by-step derivation
      1. rec-exp74.5%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{-a}}} \]
    7. Simplified74.5%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
    8. Taylor expanded in a around 0 62.7%

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

    if 4.69999999999999968e153 < 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. metadata-eval100.0%

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

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

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

        \[\leadsto \frac{--1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{-a}}} \]
      8. distribute-neg-frac100.0%

        \[\leadsto \color{blue}{-\frac{-1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      9. distribute-frac-neg2100.0%

        \[\leadsto \color{blue}{\frac{-1}{-\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      10. distribute-lft-neg-out100.0%

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

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

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

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

        \[\leadsto \frac{-1}{\color{blue}{e^{-a} \cdot \left(\left(-e^{b}\right) - e^{a}\right)}} \]
      15. sub-neg100.0%

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

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

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

      \[\leadsto \color{blue}{\frac{-1}{-1 - \frac{e^{b}}{e^{a}}}} \]
    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 0 100.0%

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + 0.5 \cdot b\right)}} \]
    7. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto \frac{1}{2 + b \cdot \left(1 + \color{blue}{b \cdot 0.5}\right)} \]
    8. Simplified100.0%

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + b \cdot 0.5\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification66.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 4.7 \cdot 10^{+153}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(a \cdot 0.5 + -1\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot 0.5\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 9: 64.3% accurate, 19.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 10^{+154}:\\ \;\;\;\;\frac{1}{2 + \left(a \cdot \left(a \cdot 0.5\right) - a\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot 0.5\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b 1e+154)
   (/ 1.0 (+ 2.0 (- (* a (* a 0.5)) a)))
   (/ 1.0 (+ 2.0 (* b (+ 1.0 (* b 0.5)))))))
double code(double a, double b) {
	double tmp;
	if (b <= 1e+154) {
		tmp = 1.0 / (2.0 + ((a * (a * 0.5)) - a));
	} 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 <= 1d+154) then
        tmp = 1.0d0 / (2.0d0 + ((a * (a * 0.5d0)) - a))
    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 <= 1e+154) {
		tmp = 1.0 / (2.0 + ((a * (a * 0.5)) - a));
	} else {
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= 1e+154:
		tmp = 1.0 / (2.0 + ((a * (a * 0.5)) - a))
	else:
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))))
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= 1e+154)
		tmp = Float64(1.0 / Float64(2.0 + Float64(Float64(a * Float64(a * 0.5)) - a)));
	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 <= 1e+154)
		tmp = 1.0 / (2.0 + ((a * (a * 0.5)) - a));
	else
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, 1e+154], N[(1.0 / N[(2.0 + N[(N[(a * N[(a * 0.5), $MachinePrecision]), $MachinePrecision] - a), $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 10^{+154}:\\
\;\;\;\;\frac{1}{2 + \left(a \cdot \left(a \cdot 0.5\right) - a\right)}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < 1.00000000000000004e154

    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/97.8%

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

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. metadata-eval97.8%

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

        \[\leadsto \frac{--1}{\frac{\color{blue}{\left(e^{a} + e^{b}\right) \cdot 1}}{e^{a}}} \]
      6. associate-*r/97.8%

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

        \[\leadsto \frac{--1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{-a}}} \]
      8. distribute-neg-frac97.8%

        \[\leadsto \color{blue}{-\frac{-1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      9. distribute-frac-neg297.8%

        \[\leadsto \color{blue}{\frac{-1}{-\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      10. distribute-lft-neg-out97.8%

        \[\leadsto \frac{-1}{\color{blue}{\left(-\left(e^{a} + e^{b}\right)\right) \cdot e^{-a}}} \]
      11. +-commutative97.8%

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

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

        \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) - e^{a}\right)} \cdot e^{-a}} \]
      14. *-commutative97.8%

        \[\leadsto \frac{-1}{\color{blue}{e^{-a} \cdot \left(\left(-e^{b}\right) - e^{a}\right)}} \]
      15. sub-neg97.8%

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

        \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(-\left(e^{b} + e^{a}\right)\right)}} \]
      17. +-commutative97.8%

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

      \[\leadsto \color{blue}{\frac{-1}{-1 - \frac{e^{b}}{e^{a}}}} \]
    4. Add Preprocessing
    5. Taylor expanded in b around 0 74.5%

      \[\leadsto \color{blue}{\frac{1}{1 + \frac{1}{e^{a}}}} \]
    6. Step-by-step derivation
      1. rec-exp74.5%

        \[\leadsto \frac{1}{1 + \color{blue}{e^{-a}}} \]
    7. Simplified74.5%

      \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
    8. Taylor expanded in a around 0 62.7%

      \[\leadsto \frac{1}{\color{blue}{2 + a \cdot \left(0.5 \cdot a - 1\right)}} \]
    9. Step-by-step derivation
      1. sub-neg62.7%

        \[\leadsto \frac{1}{2 + a \cdot \color{blue}{\left(0.5 \cdot a + \left(-1\right)\right)}} \]
      2. metadata-eval62.7%

        \[\leadsto \frac{1}{2 + a \cdot \left(0.5 \cdot a + \color{blue}{-1}\right)} \]
      3. distribute-rgt-in62.7%

        \[\leadsto \frac{1}{2 + \color{blue}{\left(\left(0.5 \cdot a\right) \cdot a + -1 \cdot a\right)}} \]
      4. *-commutative62.7%

        \[\leadsto \frac{1}{2 + \left(\color{blue}{\left(a \cdot 0.5\right)} \cdot a + -1 \cdot a\right)} \]
      5. neg-mul-162.7%

        \[\leadsto \frac{1}{2 + \left(\left(a \cdot 0.5\right) \cdot a + \color{blue}{\left(-a\right)}\right)} \]
    10. Applied egg-rr62.7%

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

    if 1.00000000000000004e154 < 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. metadata-eval100.0%

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

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

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

        \[\leadsto \frac{--1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{-a}}} \]
      8. distribute-neg-frac100.0%

        \[\leadsto \color{blue}{-\frac{-1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      9. distribute-frac-neg2100.0%

        \[\leadsto \color{blue}{\frac{-1}{-\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
      10. distribute-lft-neg-out100.0%

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

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

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

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

        \[\leadsto \frac{-1}{\color{blue}{e^{-a} \cdot \left(\left(-e^{b}\right) - e^{a}\right)}} \]
      15. sub-neg100.0%

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

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

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

      \[\leadsto \color{blue}{\frac{-1}{-1 - \frac{e^{b}}{e^{a}}}} \]
    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 0 100.0%

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + 0.5 \cdot b\right)}} \]
    7. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto \frac{1}{2 + b \cdot \left(1 + \color{blue}{b \cdot 0.5}\right)} \]
    8. Simplified100.0%

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + b \cdot 0.5\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification66.6%

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

Alternative 10: 53.0% accurate, 27.7× speedup?

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

\\
\frac{1}{2 + a \cdot \left(a \cdot 0.5 + -1\right)}
\end{array}
Derivation
  1. Initial program 98.0%

    \[\frac{e^{a}}{e^{a} + e^{b}} \]
  2. Step-by-step derivation
    1. *-lft-identity98.0%

      \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
    2. associate-*l/98.0%

      \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
    3. associate-/r/98.0%

      \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
    4. metadata-eval98.0%

      \[\leadsto \frac{\color{blue}{--1}}{\frac{e^{a} + e^{b}}{e^{a}}} \]
    5. *-rgt-identity98.0%

      \[\leadsto \frac{--1}{\frac{\color{blue}{\left(e^{a} + e^{b}\right) \cdot 1}}{e^{a}}} \]
    6. associate-*r/98.0%

      \[\leadsto \frac{--1}{\color{blue}{\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}}} \]
    7. exp-neg98.0%

      \[\leadsto \frac{--1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{-a}}} \]
    8. distribute-neg-frac98.0%

      \[\leadsto \color{blue}{-\frac{-1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
    9. distribute-frac-neg298.0%

      \[\leadsto \color{blue}{\frac{-1}{-\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
    10. distribute-lft-neg-out98.0%

      \[\leadsto \frac{-1}{\color{blue}{\left(-\left(e^{a} + e^{b}\right)\right) \cdot e^{-a}}} \]
    11. +-commutative98.0%

      \[\leadsto \frac{-1}{\left(-\color{blue}{\left(e^{b} + e^{a}\right)}\right) \cdot e^{-a}} \]
    12. distribute-neg-in98.0%

      \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) + \left(-e^{a}\right)\right)} \cdot e^{-a}} \]
    13. sub-neg98.0%

      \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) - e^{a}\right)} \cdot e^{-a}} \]
    14. *-commutative98.0%

      \[\leadsto \frac{-1}{\color{blue}{e^{-a} \cdot \left(\left(-e^{b}\right) - e^{a}\right)}} \]
    15. sub-neg98.0%

      \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(\left(-e^{b}\right) + \left(-e^{a}\right)\right)}} \]
    16. distribute-neg-in98.0%

      \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(-\left(e^{b} + e^{a}\right)\right)}} \]
    17. +-commutative98.0%

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

    \[\leadsto \color{blue}{\frac{-1}{-1 - \frac{e^{b}}{e^{a}}}} \]
  4. Add Preprocessing
  5. Taylor expanded in b around 0 70.4%

    \[\leadsto \color{blue}{\frac{1}{1 + \frac{1}{e^{a}}}} \]
  6. Step-by-step derivation
    1. rec-exp70.4%

      \[\leadsto \frac{1}{1 + \color{blue}{e^{-a}}} \]
  7. Simplified70.4%

    \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
  8. Taylor expanded in a around 0 58.7%

    \[\leadsto \frac{1}{\color{blue}{2 + a \cdot \left(0.5 \cdot a - 1\right)}} \]
  9. Final simplification58.7%

    \[\leadsto \frac{1}{2 + a \cdot \left(a \cdot 0.5 + -1\right)} \]
  10. Add Preprocessing

Alternative 11: 40.0% accurate, 61.0× speedup?

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

\\
0.5 + a \cdot 0.25
\end{array}
Derivation
  1. Initial program 98.0%

    \[\frac{e^{a}}{e^{a} + e^{b}} \]
  2. Step-by-step derivation
    1. *-lft-identity98.0%

      \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
    2. associate-*l/98.0%

      \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
    3. associate-/r/98.0%

      \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
    4. metadata-eval98.0%

      \[\leadsto \frac{\color{blue}{--1}}{\frac{e^{a} + e^{b}}{e^{a}}} \]
    5. *-rgt-identity98.0%

      \[\leadsto \frac{--1}{\frac{\color{blue}{\left(e^{a} + e^{b}\right) \cdot 1}}{e^{a}}} \]
    6. associate-*r/98.0%

      \[\leadsto \frac{--1}{\color{blue}{\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}}} \]
    7. exp-neg98.0%

      \[\leadsto \frac{--1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{-a}}} \]
    8. distribute-neg-frac98.0%

      \[\leadsto \color{blue}{-\frac{-1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
    9. distribute-frac-neg298.0%

      \[\leadsto \color{blue}{\frac{-1}{-\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
    10. distribute-lft-neg-out98.0%

      \[\leadsto \frac{-1}{\color{blue}{\left(-\left(e^{a} + e^{b}\right)\right) \cdot e^{-a}}} \]
    11. +-commutative98.0%

      \[\leadsto \frac{-1}{\left(-\color{blue}{\left(e^{b} + e^{a}\right)}\right) \cdot e^{-a}} \]
    12. distribute-neg-in98.0%

      \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) + \left(-e^{a}\right)\right)} \cdot e^{-a}} \]
    13. sub-neg98.0%

      \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) - e^{a}\right)} \cdot e^{-a}} \]
    14. *-commutative98.0%

      \[\leadsto \frac{-1}{\color{blue}{e^{-a} \cdot \left(\left(-e^{b}\right) - e^{a}\right)}} \]
    15. sub-neg98.0%

      \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(\left(-e^{b}\right) + \left(-e^{a}\right)\right)}} \]
    16. distribute-neg-in98.0%

      \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(-\left(e^{b} + e^{a}\right)\right)}} \]
    17. +-commutative98.0%

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

    \[\leadsto \color{blue}{\frac{-1}{-1 - \frac{e^{b}}{e^{a}}}} \]
  4. Add Preprocessing
  5. Taylor expanded in b around 0 70.4%

    \[\leadsto \color{blue}{\frac{1}{1 + \frac{1}{e^{a}}}} \]
  6. Step-by-step derivation
    1. rec-exp70.4%

      \[\leadsto \frac{1}{1 + \color{blue}{e^{-a}}} \]
  7. Simplified70.4%

    \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
  8. Taylor expanded in a around 0 43.5%

    \[\leadsto \color{blue}{0.5 + 0.25 \cdot a} \]
  9. Step-by-step derivation
    1. *-commutative43.5%

      \[\leadsto 0.5 + \color{blue}{a \cdot 0.25} \]
  10. Simplified43.5%

    \[\leadsto \color{blue}{0.5 + a \cdot 0.25} \]
  11. Final simplification43.5%

    \[\leadsto 0.5 + a \cdot 0.25 \]
  12. Add Preprocessing

Alternative 12: 40.7% accurate, 61.0× speedup?

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

\\
\frac{1}{2 - a}
\end{array}
Derivation
  1. Initial program 98.0%

    \[\frac{e^{a}}{e^{a} + e^{b}} \]
  2. Step-by-step derivation
    1. *-lft-identity98.0%

      \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
    2. associate-*l/98.0%

      \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
    3. associate-/r/98.0%

      \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
    4. metadata-eval98.0%

      \[\leadsto \frac{\color{blue}{--1}}{\frac{e^{a} + e^{b}}{e^{a}}} \]
    5. *-rgt-identity98.0%

      \[\leadsto \frac{--1}{\frac{\color{blue}{\left(e^{a} + e^{b}\right) \cdot 1}}{e^{a}}} \]
    6. associate-*r/98.0%

      \[\leadsto \frac{--1}{\color{blue}{\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}}} \]
    7. exp-neg98.0%

      \[\leadsto \frac{--1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{-a}}} \]
    8. distribute-neg-frac98.0%

      \[\leadsto \color{blue}{-\frac{-1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
    9. distribute-frac-neg298.0%

      \[\leadsto \color{blue}{\frac{-1}{-\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
    10. distribute-lft-neg-out98.0%

      \[\leadsto \frac{-1}{\color{blue}{\left(-\left(e^{a} + e^{b}\right)\right) \cdot e^{-a}}} \]
    11. +-commutative98.0%

      \[\leadsto \frac{-1}{\left(-\color{blue}{\left(e^{b} + e^{a}\right)}\right) \cdot e^{-a}} \]
    12. distribute-neg-in98.0%

      \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) + \left(-e^{a}\right)\right)} \cdot e^{-a}} \]
    13. sub-neg98.0%

      \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) - e^{a}\right)} \cdot e^{-a}} \]
    14. *-commutative98.0%

      \[\leadsto \frac{-1}{\color{blue}{e^{-a} \cdot \left(\left(-e^{b}\right) - e^{a}\right)}} \]
    15. sub-neg98.0%

      \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(\left(-e^{b}\right) + \left(-e^{a}\right)\right)}} \]
    16. distribute-neg-in98.0%

      \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(-\left(e^{b} + e^{a}\right)\right)}} \]
    17. +-commutative98.0%

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

    \[\leadsto \color{blue}{\frac{-1}{-1 - \frac{e^{b}}{e^{a}}}} \]
  4. Add Preprocessing
  5. Taylor expanded in b around 0 70.4%

    \[\leadsto \color{blue}{\frac{1}{1 + \frac{1}{e^{a}}}} \]
  6. Step-by-step derivation
    1. rec-exp70.4%

      \[\leadsto \frac{1}{1 + \color{blue}{e^{-a}}} \]
  7. Simplified70.4%

    \[\leadsto \color{blue}{\frac{1}{1 + e^{-a}}} \]
  8. Taylor expanded in a around 0 44.2%

    \[\leadsto \frac{1}{\color{blue}{2 + -1 \cdot a}} \]
  9. Step-by-step derivation
    1. neg-mul-144.2%

      \[\leadsto \frac{1}{2 + \color{blue}{\left(-a\right)}} \]
    2. unsub-neg44.2%

      \[\leadsto \frac{1}{\color{blue}{2 - a}} \]
  10. Simplified44.2%

    \[\leadsto \frac{1}{\color{blue}{2 - a}} \]
  11. Final simplification44.2%

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

Alternative 13: 39.9% accurate, 305.0× speedup?

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

\\
0.5
\end{array}
Derivation
  1. Initial program 98.0%

    \[\frac{e^{a}}{e^{a} + e^{b}} \]
  2. Step-by-step derivation
    1. *-lft-identity98.0%

      \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
    2. associate-*l/98.0%

      \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
    3. associate-/r/98.0%

      \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
    4. metadata-eval98.0%

      \[\leadsto \frac{\color{blue}{--1}}{\frac{e^{a} + e^{b}}{e^{a}}} \]
    5. *-rgt-identity98.0%

      \[\leadsto \frac{--1}{\frac{\color{blue}{\left(e^{a} + e^{b}\right) \cdot 1}}{e^{a}}} \]
    6. associate-*r/98.0%

      \[\leadsto \frac{--1}{\color{blue}{\left(e^{a} + e^{b}\right) \cdot \frac{1}{e^{a}}}} \]
    7. exp-neg98.0%

      \[\leadsto \frac{--1}{\left(e^{a} + e^{b}\right) \cdot \color{blue}{e^{-a}}} \]
    8. distribute-neg-frac98.0%

      \[\leadsto \color{blue}{-\frac{-1}{\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
    9. distribute-frac-neg298.0%

      \[\leadsto \color{blue}{\frac{-1}{-\left(e^{a} + e^{b}\right) \cdot e^{-a}}} \]
    10. distribute-lft-neg-out98.0%

      \[\leadsto \frac{-1}{\color{blue}{\left(-\left(e^{a} + e^{b}\right)\right) \cdot e^{-a}}} \]
    11. +-commutative98.0%

      \[\leadsto \frac{-1}{\left(-\color{blue}{\left(e^{b} + e^{a}\right)}\right) \cdot e^{-a}} \]
    12. distribute-neg-in98.0%

      \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) + \left(-e^{a}\right)\right)} \cdot e^{-a}} \]
    13. sub-neg98.0%

      \[\leadsto \frac{-1}{\color{blue}{\left(\left(-e^{b}\right) - e^{a}\right)} \cdot e^{-a}} \]
    14. *-commutative98.0%

      \[\leadsto \frac{-1}{\color{blue}{e^{-a} \cdot \left(\left(-e^{b}\right) - e^{a}\right)}} \]
    15. sub-neg98.0%

      \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(\left(-e^{b}\right) + \left(-e^{a}\right)\right)}} \]
    16. distribute-neg-in98.0%

      \[\leadsto \frac{-1}{e^{-a} \cdot \color{blue}{\left(-\left(e^{b} + e^{a}\right)\right)}} \]
    17. +-commutative98.0%

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

    \[\leadsto \color{blue}{\frac{-1}{-1 - \frac{e^{b}}{e^{a}}}} \]
  4. Add Preprocessing
  5. Taylor expanded in a around 0 80.7%

    \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
  6. Taylor expanded in b around 0 43.3%

    \[\leadsto \color{blue}{0.5} \]
  7. Final simplification43.3%

    \[\leadsto 0.5 \]
  8. 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 2024095 
(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))))