Quotient of sum of exps

Percentage Accurate: 98.8% → 100.0%
Time: 8.2s
Alternatives: 16
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 16 alternatives:

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

Initial Program: 98.8% 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, 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}
Derivation
  1. Initial program 98.4%

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

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

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

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

      \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
    5. unsub-neg98.4%

      \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
    6. div-sub69.9%

      \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
    7. *-lft-identity69.9%

      \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
    8. associate-*l/69.9%

      \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
    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. Add Preprocessing

Alternative 2: 98.4% accurate, 2.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -30500:\\ \;\;\;\;\frac{e^{a}}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{1 + e^{b}}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= a -30500.0) (/ (exp a) b) (/ 1.0 (+ 1.0 (exp b)))))
double code(double a, double b) {
	double tmp;
	if (a <= -30500.0) {
		tmp = exp(a) / b;
	} else {
		tmp = 1.0 / (1.0 + exp(b));
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (a <= (-30500.0d0)) then
        tmp = exp(a) / b
    else
        tmp = 1.0d0 / (1.0d0 + exp(b))
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (a <= -30500.0) {
		tmp = Math.exp(a) / b;
	} else {
		tmp = 1.0 / (1.0 + Math.exp(b));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if a <= -30500.0:
		tmp = math.exp(a) / b
	else:
		tmp = 1.0 / (1.0 + math.exp(b))
	return tmp
function code(a, b)
	tmp = 0.0
	if (a <= -30500.0)
		tmp = Float64(exp(a) / b);
	else
		tmp = Float64(1.0 / Float64(1.0 + exp(b)));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (a <= -30500.0)
		tmp = exp(a) / b;
	else
		tmp = 1.0 / (1.0 + exp(b));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[a, -30500.0], N[(N[Exp[a], $MachinePrecision] / b), $MachinePrecision], N[(1.0 / N[(1.0 + N[Exp[b], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \leq -30500:\\
\;\;\;\;\frac{e^{a}}{b}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if a < -30500

    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 68.1%

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

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

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

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

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{b + 1}}{e^{a}}} \]
      5. +-commutative100.0%

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

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

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

    if -30500 < a

    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. 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-sub97.3%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity97.3%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/97.3%

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

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg98.9%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg98.9%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg98.9%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
      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 97.7%

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

Alternative 3: 75.1% accurate, 2.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -550:\\ \;\;\;\;\frac{e^{a}}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= a -550.0)
   (/ (exp a) b)
   (/ 1.0 (+ 2.0 (* b (+ 1.0 (* b (+ 0.5 (* b 0.16666666666666666)))))))))
double code(double a, double b) {
	double tmp;
	if (a <= -550.0) {
		tmp = exp(a) / b;
	} 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 (a <= (-550.0d0)) then
        tmp = exp(a) / b
    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 (a <= -550.0) {
		tmp = Math.exp(a) / b;
	} else {
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * (0.5 + (b * 0.16666666666666666))))));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if a <= -550.0:
		tmp = math.exp(a) / b
	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 (a <= -550.0)
		tmp = Float64(exp(a) / b);
	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 (a <= -550.0)
		tmp = exp(a) / b;
	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[a, -550.0], N[(N[Exp[a], $MachinePrecision] / b), $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}\;a \leq -550:\\
\;\;\;\;\frac{e^{a}}{b}\\

\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 a < -550

    1. Initial program 97.3%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity97.3%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/97.3%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/97.3%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg97.3%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg97.3%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      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-inverse97.3%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg97.3%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg97.3%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg97.3%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
      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 65.3%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    6. Step-by-step derivation
      1. distribute-rgt1-in97.4%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp97.4%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/97.4%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. *-rgt-identity97.4%

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

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    7. Simplified97.4%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    8. Taylor expanded in b around inf 97.4%

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

    if -550 < 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/98.9%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg98.9%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg98.9%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub98.9%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity98.9%

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

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      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 98.2%

      \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
    6. Taylor expanded in b around 0 65.5%

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + b \cdot \left(0.5 + 0.16666666666666666 \cdot b\right)\right)}} \]
    7. Step-by-step derivation
      1. *-commutative65.5%

        \[\leadsto \frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + \color{blue}{b \cdot 0.16666666666666666}\right)\right)} \]
    8. Simplified65.5%

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

Alternative 4: 73.1% accurate, 7.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -400:\\ \;\;\;\;0.5\\ \mathbf{elif}\;b \leq 1.05 \cdot 10^{+103}:\\ \;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 - b \cdot \left(0.16666666666666666 \cdot \left(a + \frac{a}{b}\right)\right)\right) + \left(b - b \cdot 0.5\right)\right) + \left(-1 - b\right)\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b -400.0)
   0.5
   (if (<= b 1.05e+103)
     (/
      1.0
      (+
       2.0
       (+
        b
        (*
         a
         (+
          (*
           a
           (+
            (- 0.5 (* b (* 0.16666666666666666 (+ a (/ a b)))))
            (- b (* b 0.5))))
          (- -1.0 b))))))
     (/ 1.0 (+ 2.0 (* b (+ 1.0 (* b (+ 0.5 (* b 0.16666666666666666))))))))))
double code(double a, double b) {
	double tmp;
	if (b <= -400.0) {
		tmp = 0.5;
	} else if (b <= 1.05e+103) {
		tmp = 1.0 / (2.0 + (b + (a * ((a * ((0.5 - (b * (0.16666666666666666 * (a + (a / b))))) + (b - (b * 0.5)))) + (-1.0 - b)))));
	} 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 <= (-400.0d0)) then
        tmp = 0.5d0
    else if (b <= 1.05d+103) then
        tmp = 1.0d0 / (2.0d0 + (b + (a * ((a * ((0.5d0 - (b * (0.16666666666666666d0 * (a + (a / b))))) + (b - (b * 0.5d0)))) + ((-1.0d0) - b)))))
    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 <= -400.0) {
		tmp = 0.5;
	} else if (b <= 1.05e+103) {
		tmp = 1.0 / (2.0 + (b + (a * ((a * ((0.5 - (b * (0.16666666666666666 * (a + (a / b))))) + (b - (b * 0.5)))) + (-1.0 - b)))));
	} 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 <= -400.0:
		tmp = 0.5
	elif b <= 1.05e+103:
		tmp = 1.0 / (2.0 + (b + (a * ((a * ((0.5 - (b * (0.16666666666666666 * (a + (a / b))))) + (b - (b * 0.5)))) + (-1.0 - b)))))
	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 <= -400.0)
		tmp = 0.5;
	elseif (b <= 1.05e+103)
		tmp = Float64(1.0 / Float64(2.0 + Float64(b + Float64(a * Float64(Float64(a * Float64(Float64(0.5 - Float64(b * Float64(0.16666666666666666 * Float64(a + Float64(a / b))))) + Float64(b - Float64(b * 0.5)))) + Float64(-1.0 - b))))));
	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 <= -400.0)
		tmp = 0.5;
	elseif (b <= 1.05e+103)
		tmp = 1.0 / (2.0 + (b + (a * ((a * ((0.5 - (b * (0.16666666666666666 * (a + (a / b))))) + (b - (b * 0.5)))) + (-1.0 - b)))));
	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, -400.0], 0.5, If[LessEqual[b, 1.05e+103], N[(1.0 / N[(2.0 + N[(b + N[(a * N[(N[(a * N[(N[(0.5 - N[(b * N[(0.16666666666666666 * N[(a + N[(a / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(b - N[(b * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-1.0 - b), $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 -400:\\
\;\;\;\;0.5\\

\mathbf{elif}\;b \leq 1.05 \cdot 10^{+103}:\\
\;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 - b \cdot \left(0.16666666666666666 \cdot \left(a + \frac{a}{b}\right)\right)\right) + \left(b - b \cdot 0.5\right)\right) + \left(-1 - b\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 < -400

    1. Initial program 92.7%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity92.7%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/92.7%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/92.7%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg92.7%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg92.7%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub92.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity92.7%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/92.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse96.4%

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

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg96.4%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg96.4%

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

      \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
    6. Taylor expanded in b around 0 18.8%

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

    if -400 < b < 1.0500000000000001e103

    1. Initial program 99.9%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity99.9%

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

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/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-sub64.7%

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

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/64.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      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 79.4%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    6. Step-by-step derivation
      1. distribute-rgt1-in94.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp94.8%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/94.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. *-rgt-identity94.8%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{b + 1}}{e^{a}}} \]
      5. +-commutative94.8%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    7. Simplified94.8%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    8. Taylor expanded in a around 0 83.5%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + \left(-1 \cdot \left(-1 \cdot b + 0.5 \cdot b\right) + \left(-0.5 \cdot b + 0.16666666666666666 \cdot b\right)\right)\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)}} \]
    9. Taylor expanded in b around inf 84.7%

      \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \color{blue}{\left(b \cdot \left(0.16666666666666666 \cdot a + 0.16666666666666666 \cdot \frac{a}{b}\right)\right)}\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
    10. Step-by-step derivation
      1. distribute-lft-out84.7%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(b \cdot \color{blue}{\left(0.16666666666666666 \cdot \left(a + \frac{a}{b}\right)\right)}\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
    11. Simplified84.7%

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

    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. 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%

      \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
    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 3 regimes into one program.
  4. Final simplification73.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -400:\\ \;\;\;\;0.5\\ \mathbf{elif}\;b \leq 1.05 \cdot 10^{+103}:\\ \;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 - b \cdot \left(0.16666666666666666 \cdot \left(a + \frac{a}{b}\right)\right)\right) + \left(b - b \cdot 0.5\right)\right) + \left(-1 - b\right)\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 73.0% accurate, 7.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -4100:\\ \;\;\;\;0.5\\ \mathbf{elif}\;b \leq 5.2 \cdot 10^{+102}:\\ \;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 - b \cdot \left(0.16666666666666666 \cdot \frac{a}{b}\right)\right) + \left(b - b \cdot 0.5\right)\right) + \left(-1 - b\right)\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b -4100.0)
   0.5
   (if (<= b 5.2e+102)
     (/
      1.0
      (+
       2.0
       (+
        b
        (*
         a
         (+
          (*
           a
           (+ (- 0.5 (* b (* 0.16666666666666666 (/ a b)))) (- b (* b 0.5))))
          (- -1.0 b))))))
     (/ 1.0 (+ 2.0 (* b (+ 1.0 (* b (+ 0.5 (* b 0.16666666666666666))))))))))
double code(double a, double b) {
	double tmp;
	if (b <= -4100.0) {
		tmp = 0.5;
	} else if (b <= 5.2e+102) {
		tmp = 1.0 / (2.0 + (b + (a * ((a * ((0.5 - (b * (0.16666666666666666 * (a / b)))) + (b - (b * 0.5)))) + (-1.0 - b)))));
	} 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 <= (-4100.0d0)) then
        tmp = 0.5d0
    else if (b <= 5.2d+102) then
        tmp = 1.0d0 / (2.0d0 + (b + (a * ((a * ((0.5d0 - (b * (0.16666666666666666d0 * (a / b)))) + (b - (b * 0.5d0)))) + ((-1.0d0) - b)))))
    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 <= -4100.0) {
		tmp = 0.5;
	} else if (b <= 5.2e+102) {
		tmp = 1.0 / (2.0 + (b + (a * ((a * ((0.5 - (b * (0.16666666666666666 * (a / b)))) + (b - (b * 0.5)))) + (-1.0 - b)))));
	} 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 <= -4100.0:
		tmp = 0.5
	elif b <= 5.2e+102:
		tmp = 1.0 / (2.0 + (b + (a * ((a * ((0.5 - (b * (0.16666666666666666 * (a / b)))) + (b - (b * 0.5)))) + (-1.0 - b)))))
	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 <= -4100.0)
		tmp = 0.5;
	elseif (b <= 5.2e+102)
		tmp = Float64(1.0 / Float64(2.0 + Float64(b + Float64(a * Float64(Float64(a * Float64(Float64(0.5 - Float64(b * Float64(0.16666666666666666 * Float64(a / b)))) + Float64(b - Float64(b * 0.5)))) + Float64(-1.0 - b))))));
	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 <= -4100.0)
		tmp = 0.5;
	elseif (b <= 5.2e+102)
		tmp = 1.0 / (2.0 + (b + (a * ((a * ((0.5 - (b * (0.16666666666666666 * (a / b)))) + (b - (b * 0.5)))) + (-1.0 - b)))));
	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, -4100.0], 0.5, If[LessEqual[b, 5.2e+102], N[(1.0 / N[(2.0 + N[(b + N[(a * N[(N[(a * N[(N[(0.5 - N[(b * N[(0.16666666666666666 * N[(a / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(b - N[(b * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-1.0 - b), $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 -4100:\\
\;\;\;\;0.5\\

\mathbf{elif}\;b \leq 5.2 \cdot 10^{+102}:\\
\;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 - b \cdot \left(0.16666666666666666 \cdot \frac{a}{b}\right)\right) + \left(b - b \cdot 0.5\right)\right) + \left(-1 - b\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 < -4100

    1. Initial program 92.7%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity92.7%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/92.7%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/92.7%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg92.7%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg92.7%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub92.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity92.7%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/92.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse96.4%

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

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg96.4%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg96.4%

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

      \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
    6. Taylor expanded in b around 0 18.8%

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

    if -4100 < b < 5.20000000000000013e102

    1. Initial program 99.9%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity99.9%

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

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/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-sub64.7%

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

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/64.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      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 79.4%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    6. Step-by-step derivation
      1. distribute-rgt1-in94.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp94.8%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/94.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. *-rgt-identity94.8%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{b + 1}}{e^{a}}} \]
      5. +-commutative94.8%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    7. Simplified94.8%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    8. Taylor expanded in a around 0 83.5%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + \left(-1 \cdot \left(-1 \cdot b + 0.5 \cdot b\right) + \left(-0.5 \cdot b + 0.16666666666666666 \cdot b\right)\right)\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)}} \]
    9. Taylor expanded in b around inf 84.7%

      \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \color{blue}{\left(b \cdot \left(0.16666666666666666 \cdot a + 0.16666666666666666 \cdot \frac{a}{b}\right)\right)}\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
    10. Step-by-step derivation
      1. distribute-lft-out84.7%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(b \cdot \color{blue}{\left(0.16666666666666666 \cdot \left(a + \frac{a}{b}\right)\right)}\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
    11. Simplified84.7%

      \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \color{blue}{\left(b \cdot \left(0.16666666666666666 \cdot \left(a + \frac{a}{b}\right)\right)\right)}\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
    12. Taylor expanded in b around 0 84.7%

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

    if 5.20000000000000013e102 < 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%

      \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
    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 3 regimes into one program.
  4. Final simplification73.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -4100:\\ \;\;\;\;0.5\\ \mathbf{elif}\;b \leq 5.2 \cdot 10^{+102}:\\ \;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 - b \cdot \left(0.16666666666666666 \cdot \frac{a}{b}\right)\right) + \left(b - b \cdot 0.5\right)\right) + \left(-1 - b\right)\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 72.1% accurate, 7.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -60:\\ \;\;\;\;0.5\\ \mathbf{elif}\;b \leq 10^{+103}:\\ \;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 - a \cdot \left(0.16666666666666666 + b \cdot -0.8333333333333334\right)\right) + \left(b - b \cdot 0.5\right)\right) + \left(-1 - b\right)\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b -60.0)
   0.5
   (if (<= b 1e+103)
     (/
      1.0
      (+
       2.0
       (+
        b
        (*
         a
         (+
          (*
           a
           (+
            (- 0.5 (* a (+ 0.16666666666666666 (* b -0.8333333333333334))))
            (- b (* b 0.5))))
          (- -1.0 b))))))
     (/ 1.0 (+ 2.0 (* b (+ 1.0 (* b (+ 0.5 (* b 0.16666666666666666))))))))))
double code(double a, double b) {
	double tmp;
	if (b <= -60.0) {
		tmp = 0.5;
	} else if (b <= 1e+103) {
		tmp = 1.0 / (2.0 + (b + (a * ((a * ((0.5 - (a * (0.16666666666666666 + (b * -0.8333333333333334)))) + (b - (b * 0.5)))) + (-1.0 - b)))));
	} 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 <= (-60.0d0)) then
        tmp = 0.5d0
    else if (b <= 1d+103) then
        tmp = 1.0d0 / (2.0d0 + (b + (a * ((a * ((0.5d0 - (a * (0.16666666666666666d0 + (b * (-0.8333333333333334d0))))) + (b - (b * 0.5d0)))) + ((-1.0d0) - b)))))
    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 <= -60.0) {
		tmp = 0.5;
	} else if (b <= 1e+103) {
		tmp = 1.0 / (2.0 + (b + (a * ((a * ((0.5 - (a * (0.16666666666666666 + (b * -0.8333333333333334)))) + (b - (b * 0.5)))) + (-1.0 - b)))));
	} 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 <= -60.0:
		tmp = 0.5
	elif b <= 1e+103:
		tmp = 1.0 / (2.0 + (b + (a * ((a * ((0.5 - (a * (0.16666666666666666 + (b * -0.8333333333333334)))) + (b - (b * 0.5)))) + (-1.0 - b)))))
	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 <= -60.0)
		tmp = 0.5;
	elseif (b <= 1e+103)
		tmp = Float64(1.0 / Float64(2.0 + Float64(b + Float64(a * Float64(Float64(a * Float64(Float64(0.5 - Float64(a * Float64(0.16666666666666666 + Float64(b * -0.8333333333333334)))) + Float64(b - Float64(b * 0.5)))) + Float64(-1.0 - b))))));
	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 <= -60.0)
		tmp = 0.5;
	elseif (b <= 1e+103)
		tmp = 1.0 / (2.0 + (b + (a * ((a * ((0.5 - (a * (0.16666666666666666 + (b * -0.8333333333333334)))) + (b - (b * 0.5)))) + (-1.0 - b)))));
	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, -60.0], 0.5, If[LessEqual[b, 1e+103], N[(1.0 / N[(2.0 + N[(b + N[(a * N[(N[(a * N[(N[(0.5 - N[(a * N[(0.16666666666666666 + N[(b * -0.8333333333333334), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(b - N[(b * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-1.0 - b), $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 -60:\\
\;\;\;\;0.5\\

\mathbf{elif}\;b \leq 10^{+103}:\\
\;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 - a \cdot \left(0.16666666666666666 + b \cdot -0.8333333333333334\right)\right) + \left(b - b \cdot 0.5\right)\right) + \left(-1 - b\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 < -60

    1. Initial program 92.7%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity92.7%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/92.7%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/92.7%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg92.7%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg92.7%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub92.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity92.7%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/92.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse96.4%

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

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg96.4%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg96.4%

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

      \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
    6. Taylor expanded in b around 0 18.8%

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

    if -60 < b < 1e103

    1. Initial program 99.9%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity99.9%

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

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/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-sub64.7%

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

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/64.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      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 79.4%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    6. Step-by-step derivation
      1. distribute-rgt1-in94.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp94.8%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/94.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. *-rgt-identity94.8%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{b + 1}}{e^{a}}} \]
      5. +-commutative94.8%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    7. Simplified94.8%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    8. Taylor expanded in a around 0 83.5%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + \left(-1 \cdot \left(-1 \cdot b + 0.5 \cdot b\right) + \left(-0.5 \cdot b + 0.16666666666666666 \cdot b\right)\right)\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)}} \]
    9. Step-by-step derivation
      1. *-un-lft-identity83.5%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + \color{blue}{1 \cdot \left(-1 \cdot \left(-1 \cdot b + 0.5 \cdot b\right) + \left(-0.5 \cdot b + 0.16666666666666666 \cdot b\right)\right)}\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
      2. +-commutative83.5%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + 1 \cdot \color{blue}{\left(\left(-0.5 \cdot b + 0.16666666666666666 \cdot b\right) + -1 \cdot \left(-1 \cdot b + 0.5 \cdot b\right)\right)}\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
      3. distribute-rgt-out83.5%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + 1 \cdot \left(\color{blue}{b \cdot \left(-0.5 + 0.16666666666666666\right)} + -1 \cdot \left(-1 \cdot b + 0.5 \cdot b\right)\right)\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
      4. fma-define83.5%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + 1 \cdot \color{blue}{\mathsf{fma}\left(b, -0.5 + 0.16666666666666666, -1 \cdot \left(-1 \cdot b + 0.5 \cdot b\right)\right)}\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
      5. metadata-eval83.5%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + 1 \cdot \mathsf{fma}\left(b, \color{blue}{-0.3333333333333333}, -1 \cdot \left(-1 \cdot b + 0.5 \cdot b\right)\right)\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
      6. add-sqr-sqrt45.9%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + 1 \cdot \mathsf{fma}\left(b, -0.3333333333333333, \color{blue}{\sqrt{-1 \cdot \left(-1 \cdot b + 0.5 \cdot b\right)} \cdot \sqrt{-1 \cdot \left(-1 \cdot b + 0.5 \cdot b\right)}}\right)\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
      7. sqrt-unprod83.5%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + 1 \cdot \mathsf{fma}\left(b, -0.3333333333333333, \color{blue}{\sqrt{\left(-1 \cdot \left(-1 \cdot b + 0.5 \cdot b\right)\right) \cdot \left(-1 \cdot \left(-1 \cdot b + 0.5 \cdot b\right)\right)}}\right)\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
      8. mul-1-neg83.5%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + 1 \cdot \mathsf{fma}\left(b, -0.3333333333333333, \sqrt{\color{blue}{\left(-\left(-1 \cdot b + 0.5 \cdot b\right)\right)} \cdot \left(-1 \cdot \left(-1 \cdot b + 0.5 \cdot b\right)\right)}\right)\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
      9. mul-1-neg83.5%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + 1 \cdot \mathsf{fma}\left(b, -0.3333333333333333, \sqrt{\left(-\left(-1 \cdot b + 0.5 \cdot b\right)\right) \cdot \color{blue}{\left(-\left(-1 \cdot b + 0.5 \cdot b\right)\right)}}\right)\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
      10. sqr-neg83.5%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + 1 \cdot \mathsf{fma}\left(b, -0.3333333333333333, \sqrt{\color{blue}{\left(-1 \cdot b + 0.5 \cdot b\right) \cdot \left(-1 \cdot b + 0.5 \cdot b\right)}}\right)\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
      11. sqrt-unprod37.6%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + 1 \cdot \mathsf{fma}\left(b, -0.3333333333333333, \color{blue}{\sqrt{-1 \cdot b + 0.5 \cdot b} \cdot \sqrt{-1 \cdot b + 0.5 \cdot b}}\right)\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
      12. add-sqr-sqrt83.5%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + 1 \cdot \mathsf{fma}\left(b, -0.3333333333333333, \color{blue}{-1 \cdot b + 0.5 \cdot b}\right)\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
      13. distribute-rgt-out83.5%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + 1 \cdot \mathsf{fma}\left(b, -0.3333333333333333, \color{blue}{b \cdot \left(-1 + 0.5\right)}\right)\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
      14. metadata-eval83.5%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + 1 \cdot \mathsf{fma}\left(b, -0.3333333333333333, b \cdot \color{blue}{-0.5}\right)\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
    10. Applied egg-rr83.5%

      \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + \color{blue}{1 \cdot \mathsf{fma}\left(b, -0.3333333333333333, b \cdot -0.5\right)}\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
    11. Step-by-step derivation
      1. *-lft-identity83.5%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + \color{blue}{\mathsf{fma}\left(b, -0.3333333333333333, b \cdot -0.5\right)}\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
      2. fma-undefine83.5%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + \color{blue}{\left(b \cdot -0.3333333333333333 + b \cdot -0.5\right)}\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
      3. distribute-lft-out83.5%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + \color{blue}{b \cdot \left(-0.3333333333333333 + -0.5\right)}\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
      4. metadata-eval83.5%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + b \cdot \color{blue}{-0.8333333333333334}\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
    12. Simplified83.5%

      \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + \color{blue}{b \cdot -0.8333333333333334}\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]

    if 1e103 < 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%

      \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
    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 3 regimes into one program.
  4. Final simplification72.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -60:\\ \;\;\;\;0.5\\ \mathbf{elif}\;b \leq 10^{+103}:\\ \;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 - a \cdot \left(0.16666666666666666 + b \cdot -0.8333333333333334\right)\right) + \left(b - b \cdot 0.5\right)\right) + \left(-1 - b\right)\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 72.0% accurate, 8.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -35:\\ \;\;\;\;0.5\\ \mathbf{elif}\;b \leq 3.3 \cdot 10^{+102}:\\ \;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 - a \cdot 0.16666666666666666\right) + \left(b - b \cdot 0.5\right)\right) + \left(-1 - b\right)\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b -35.0)
   0.5
   (if (<= b 3.3e+102)
     (/
      1.0
      (+
       2.0
       (+
        b
        (*
         a
         (+
          (* a (+ (- 0.5 (* a 0.16666666666666666)) (- b (* b 0.5))))
          (- -1.0 b))))))
     (/ 1.0 (+ 2.0 (* b (+ 1.0 (* b (+ 0.5 (* b 0.16666666666666666))))))))))
double code(double a, double b) {
	double tmp;
	if (b <= -35.0) {
		tmp = 0.5;
	} else if (b <= 3.3e+102) {
		tmp = 1.0 / (2.0 + (b + (a * ((a * ((0.5 - (a * 0.16666666666666666)) + (b - (b * 0.5)))) + (-1.0 - b)))));
	} 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 <= (-35.0d0)) then
        tmp = 0.5d0
    else if (b <= 3.3d+102) then
        tmp = 1.0d0 / (2.0d0 + (b + (a * ((a * ((0.5d0 - (a * 0.16666666666666666d0)) + (b - (b * 0.5d0)))) + ((-1.0d0) - b)))))
    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 <= -35.0) {
		tmp = 0.5;
	} else if (b <= 3.3e+102) {
		tmp = 1.0 / (2.0 + (b + (a * ((a * ((0.5 - (a * 0.16666666666666666)) + (b - (b * 0.5)))) + (-1.0 - b)))));
	} 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 <= -35.0:
		tmp = 0.5
	elif b <= 3.3e+102:
		tmp = 1.0 / (2.0 + (b + (a * ((a * ((0.5 - (a * 0.16666666666666666)) + (b - (b * 0.5)))) + (-1.0 - b)))))
	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 <= -35.0)
		tmp = 0.5;
	elseif (b <= 3.3e+102)
		tmp = Float64(1.0 / Float64(2.0 + Float64(b + Float64(a * Float64(Float64(a * Float64(Float64(0.5 - Float64(a * 0.16666666666666666)) + Float64(b - Float64(b * 0.5)))) + Float64(-1.0 - b))))));
	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 <= -35.0)
		tmp = 0.5;
	elseif (b <= 3.3e+102)
		tmp = 1.0 / (2.0 + (b + (a * ((a * ((0.5 - (a * 0.16666666666666666)) + (b - (b * 0.5)))) + (-1.0 - b)))));
	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, -35.0], 0.5, If[LessEqual[b, 3.3e+102], N[(1.0 / N[(2.0 + N[(b + N[(a * N[(N[(a * N[(N[(0.5 - N[(a * 0.16666666666666666), $MachinePrecision]), $MachinePrecision] + N[(b - N[(b * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-1.0 - b), $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 -35:\\
\;\;\;\;0.5\\

\mathbf{elif}\;b \leq 3.3 \cdot 10^{+102}:\\
\;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 - a \cdot 0.16666666666666666\right) + \left(b - b \cdot 0.5\right)\right) + \left(-1 - b\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 < -35

    1. Initial program 92.7%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity92.7%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/92.7%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/92.7%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg92.7%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg92.7%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub92.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity92.7%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/92.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse96.4%

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

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg96.4%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg96.4%

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

      \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
    6. Taylor expanded in b around 0 18.8%

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

    if -35 < b < 3.29999999999999999e102

    1. Initial program 99.9%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity99.9%

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

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/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-sub64.7%

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

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/64.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      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 79.4%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    6. Step-by-step derivation
      1. distribute-rgt1-in94.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp94.8%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/94.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. *-rgt-identity94.8%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{b + 1}}{e^{a}}} \]
      5. +-commutative94.8%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    7. Simplified94.8%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    8. Taylor expanded in a around 0 83.5%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + \left(-1 \cdot \left(-1 \cdot b + 0.5 \cdot b\right) + \left(-0.5 \cdot b + 0.16666666666666666 \cdot b\right)\right)\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)}} \]
    9. Taylor expanded in b around 0 83.5%

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

    if 3.29999999999999999e102 < 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%

      \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
    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 3 regimes into one program.
  4. Final simplification72.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -35:\\ \;\;\;\;0.5\\ \mathbf{elif}\;b \leq 3.3 \cdot 10^{+102}:\\ \;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 - a \cdot 0.16666666666666666\right) + \left(b - b \cdot 0.5\right)\right) + \left(-1 - b\right)\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 8: 70.5% accurate, 10.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := a \cdot \left(-1 + a \cdot 0.5\right)\\ \mathbf{if}\;b \leq -4.8 \cdot 10^{-178}:\\ \;\;\;\;\frac{1}{2 + t\_0}\\ \mathbf{elif}\;b \leq 2.1 \cdot 10^{-186}:\\ \;\;\;\;\frac{1}{b + \left(2 - b \cdot \left(a + \frac{a}{b}\right)\right)}\\ \mathbf{elif}\;b \leq 4 \cdot 10^{+102}:\\ \;\;\;\;\frac{1}{2 + \left(b + t\_0\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (let* ((t_0 (* a (+ -1.0 (* a 0.5)))))
   (if (<= b -4.8e-178)
     (/ 1.0 (+ 2.0 t_0))
     (if (<= b 2.1e-186)
       (/ 1.0 (+ b (- 2.0 (* b (+ a (/ a b))))))
       (if (<= b 4e+102)
         (/ 1.0 (+ 2.0 (+ b t_0)))
         (/
          1.0
          (+ 2.0 (* b (+ 1.0 (* b (+ 0.5 (* b 0.16666666666666666))))))))))))
double code(double a, double b) {
	double t_0 = a * (-1.0 + (a * 0.5));
	double tmp;
	if (b <= -4.8e-178) {
		tmp = 1.0 / (2.0 + t_0);
	} else if (b <= 2.1e-186) {
		tmp = 1.0 / (b + (2.0 - (b * (a + (a / b)))));
	} else if (b <= 4e+102) {
		tmp = 1.0 / (2.0 + (b + t_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) :: t_0
    real(8) :: tmp
    t_0 = a * ((-1.0d0) + (a * 0.5d0))
    if (b <= (-4.8d-178)) then
        tmp = 1.0d0 / (2.0d0 + t_0)
    else if (b <= 2.1d-186) then
        tmp = 1.0d0 / (b + (2.0d0 - (b * (a + (a / b)))))
    else if (b <= 4d+102) then
        tmp = 1.0d0 / (2.0d0 + (b + t_0))
    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 t_0 = a * (-1.0 + (a * 0.5));
	double tmp;
	if (b <= -4.8e-178) {
		tmp = 1.0 / (2.0 + t_0);
	} else if (b <= 2.1e-186) {
		tmp = 1.0 / (b + (2.0 - (b * (a + (a / b)))));
	} else if (b <= 4e+102) {
		tmp = 1.0 / (2.0 + (b + t_0));
	} else {
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * (0.5 + (b * 0.16666666666666666))))));
	}
	return tmp;
}
def code(a, b):
	t_0 = a * (-1.0 + (a * 0.5))
	tmp = 0
	if b <= -4.8e-178:
		tmp = 1.0 / (2.0 + t_0)
	elif b <= 2.1e-186:
		tmp = 1.0 / (b + (2.0 - (b * (a + (a / b)))))
	elif b <= 4e+102:
		tmp = 1.0 / (2.0 + (b + t_0))
	else:
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * (0.5 + (b * 0.16666666666666666))))))
	return tmp
function code(a, b)
	t_0 = Float64(a * Float64(-1.0 + Float64(a * 0.5)))
	tmp = 0.0
	if (b <= -4.8e-178)
		tmp = Float64(1.0 / Float64(2.0 + t_0));
	elseif (b <= 2.1e-186)
		tmp = Float64(1.0 / Float64(b + Float64(2.0 - Float64(b * Float64(a + Float64(a / b))))));
	elseif (b <= 4e+102)
		tmp = Float64(1.0 / Float64(2.0 + Float64(b + t_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)
	t_0 = a * (-1.0 + (a * 0.5));
	tmp = 0.0;
	if (b <= -4.8e-178)
		tmp = 1.0 / (2.0 + t_0);
	elseif (b <= 2.1e-186)
		tmp = 1.0 / (b + (2.0 - (b * (a + (a / b)))));
	elseif (b <= 4e+102)
		tmp = 1.0 / (2.0 + (b + t_0));
	else
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * (0.5 + (b * 0.16666666666666666))))));
	end
	tmp_2 = tmp;
end
code[a_, b_] := Block[{t$95$0 = N[(a * N[(-1.0 + N[(a * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[b, -4.8e-178], N[(1.0 / N[(2.0 + t$95$0), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 2.1e-186], N[(1.0 / N[(b + N[(2.0 - N[(b * N[(a + N[(a / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 4e+102], N[(1.0 / N[(2.0 + N[(b + t$95$0), $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}
t_0 := a \cdot \left(-1 + a \cdot 0.5\right)\\
\mathbf{if}\;b \leq -4.8 \cdot 10^{-178}:\\
\;\;\;\;\frac{1}{2 + t\_0}\\

\mathbf{elif}\;b \leq 2.1 \cdot 10^{-186}:\\
\;\;\;\;\frac{1}{b + \left(2 - b \cdot \left(a + \frac{a}{b}\right)\right)}\\

\mathbf{elif}\;b \leq 4 \cdot 10^{+102}:\\
\;\;\;\;\frac{1}{2 + \left(b + t\_0\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 4 regimes
  2. if b < -4.8000000000000001e-178

    1. Initial program 95.7%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity95.7%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/95.7%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/95.7%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg95.7%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg95.7%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub81.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity81.7%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/81.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      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. Taylor expanded in b around 0 29.9%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    6. Step-by-step derivation
      1. distribute-rgt1-in43.9%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp43.9%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/43.9%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. *-rgt-identity43.9%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{b + 1}}{e^{a}}} \]
      5. +-commutative43.9%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    7. Simplified43.9%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    8. Taylor expanded in a around 0 35.0%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + a \cdot \left(a \cdot \left(0.5 - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)}} \]
    9. Taylor expanded in b around 0 43.7%

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

    if -4.8000000000000001e-178 < b < 2.1000000000000002e-186

    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-sub66.0%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity66.0%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/66.0%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      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 78.0%

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

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

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

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

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{b + 1}}{e^{a}}} \]
      5. +-commutative100.0%

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

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    8. Taylor expanded in a around 0 67.9%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
    9. Step-by-step derivation
      1. associate-+r+67.9%

        \[\leadsto \frac{1}{\color{blue}{\left(2 + b\right) + -1 \cdot \left(a \cdot \left(1 + b\right)\right)}} \]
      2. +-commutative67.9%

        \[\leadsto \frac{1}{\color{blue}{\left(b + 2\right)} + -1 \cdot \left(a \cdot \left(1 + b\right)\right)} \]
      3. associate-+l+67.9%

        \[\leadsto \frac{1}{\color{blue}{b + \left(2 + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
      4. mul-1-neg67.9%

        \[\leadsto \frac{1}{b + \left(2 + \color{blue}{\left(-a \cdot \left(1 + b\right)\right)}\right)} \]
      5. distribute-rgt-neg-in67.9%

        \[\leadsto \frac{1}{b + \left(2 + \color{blue}{a \cdot \left(-\left(1 + b\right)\right)}\right)} \]
      6. distribute-neg-in67.9%

        \[\leadsto \frac{1}{b + \left(2 + a \cdot \color{blue}{\left(\left(-1\right) + \left(-b\right)\right)}\right)} \]
      7. metadata-eval67.9%

        \[\leadsto \frac{1}{b + \left(2 + a \cdot \left(\color{blue}{-1} + \left(-b\right)\right)\right)} \]
      8. unsub-neg67.9%

        \[\leadsto \frac{1}{b + \left(2 + a \cdot \color{blue}{\left(-1 - b\right)}\right)} \]
    10. Simplified67.9%

      \[\leadsto \frac{1}{\color{blue}{b + \left(2 + a \cdot \left(-1 - b\right)\right)}} \]
    11. Taylor expanded in b around inf 96.1%

      \[\leadsto \frac{1}{b + \left(2 + \color{blue}{b \cdot \left(-1 \cdot a + -1 \cdot \frac{a}{b}\right)}\right)} \]
    12. Step-by-step derivation
      1. mul-1-neg96.1%

        \[\leadsto \frac{1}{b + \left(2 + b \cdot \left(-1 \cdot a + \color{blue}{\left(-\frac{a}{b}\right)}\right)\right)} \]
      2. unsub-neg96.1%

        \[\leadsto \frac{1}{b + \left(2 + b \cdot \color{blue}{\left(-1 \cdot a - \frac{a}{b}\right)}\right)} \]
      3. mul-1-neg96.1%

        \[\leadsto \frac{1}{b + \left(2 + b \cdot \left(\color{blue}{\left(-a\right)} - \frac{a}{b}\right)\right)} \]
    13. Simplified96.1%

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

    if 2.1000000000000002e-186 < b < 3.99999999999999991e102

    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-sub63.2%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity63.2%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/63.2%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      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 88.6%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    6. Step-by-step derivation
      1. distribute-rgt1-in88.6%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp88.6%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/88.6%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. *-rgt-identity88.6%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{b + 1}}{e^{a}}} \]
      5. +-commutative88.6%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    7. Simplified88.6%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    8. Taylor expanded in a around 0 66.3%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + a \cdot \left(a \cdot \left(0.5 - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)}} \]
    9. Taylor expanded in b around 0 66.2%

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

    if 3.99999999999999991e102 < 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%

      \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
    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 4 regimes into one program.
  4. Final simplification69.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -4.8 \cdot 10^{-178}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(-1 + a \cdot 0.5\right)}\\ \mathbf{elif}\;b \leq 2.1 \cdot 10^{-186}:\\ \;\;\;\;\frac{1}{b + \left(2 - b \cdot \left(a + \frac{a}{b}\right)\right)}\\ \mathbf{elif}\;b \leq 4 \cdot 10^{+102}:\\ \;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(-1 + a \cdot 0.5\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 9: 66.6% accurate, 10.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := a \cdot \left(-1 + a \cdot 0.5\right)\\ \mathbf{if}\;b \leq -1.9 \cdot 10^{-179}:\\ \;\;\;\;\frac{1}{2 + t\_0}\\ \mathbf{elif}\;b \leq 6.4 \cdot 10^{-192}:\\ \;\;\;\;\frac{1}{b + \left(2 - b \cdot \left(a + \frac{a}{b}\right)\right)}\\ \mathbf{elif}\;b \leq 5.1 \cdot 10^{+147}:\\ \;\;\;\;\frac{1}{2 + \left(b + t\_0\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot 0.5\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (let* ((t_0 (* a (+ -1.0 (* a 0.5)))))
   (if (<= b -1.9e-179)
     (/ 1.0 (+ 2.0 t_0))
     (if (<= b 6.4e-192)
       (/ 1.0 (+ b (- 2.0 (* b (+ a (/ a b))))))
       (if (<= b 5.1e+147)
         (/ 1.0 (+ 2.0 (+ b t_0)))
         (/ 1.0 (+ 2.0 (* b (+ 1.0 (* b 0.5))))))))))
double code(double a, double b) {
	double t_0 = a * (-1.0 + (a * 0.5));
	double tmp;
	if (b <= -1.9e-179) {
		tmp = 1.0 / (2.0 + t_0);
	} else if (b <= 6.4e-192) {
		tmp = 1.0 / (b + (2.0 - (b * (a + (a / b)))));
	} else if (b <= 5.1e+147) {
		tmp = 1.0 / (2.0 + (b + t_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) :: t_0
    real(8) :: tmp
    t_0 = a * ((-1.0d0) + (a * 0.5d0))
    if (b <= (-1.9d-179)) then
        tmp = 1.0d0 / (2.0d0 + t_0)
    else if (b <= 6.4d-192) then
        tmp = 1.0d0 / (b + (2.0d0 - (b * (a + (a / b)))))
    else if (b <= 5.1d+147) then
        tmp = 1.0d0 / (2.0d0 + (b + t_0))
    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 t_0 = a * (-1.0 + (a * 0.5));
	double tmp;
	if (b <= -1.9e-179) {
		tmp = 1.0 / (2.0 + t_0);
	} else if (b <= 6.4e-192) {
		tmp = 1.0 / (b + (2.0 - (b * (a + (a / b)))));
	} else if (b <= 5.1e+147) {
		tmp = 1.0 / (2.0 + (b + t_0));
	} else {
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))));
	}
	return tmp;
}
def code(a, b):
	t_0 = a * (-1.0 + (a * 0.5))
	tmp = 0
	if b <= -1.9e-179:
		tmp = 1.0 / (2.0 + t_0)
	elif b <= 6.4e-192:
		tmp = 1.0 / (b + (2.0 - (b * (a + (a / b)))))
	elif b <= 5.1e+147:
		tmp = 1.0 / (2.0 + (b + t_0))
	else:
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))))
	return tmp
function code(a, b)
	t_0 = Float64(a * Float64(-1.0 + Float64(a * 0.5)))
	tmp = 0.0
	if (b <= -1.9e-179)
		tmp = Float64(1.0 / Float64(2.0 + t_0));
	elseif (b <= 6.4e-192)
		tmp = Float64(1.0 / Float64(b + Float64(2.0 - Float64(b * Float64(a + Float64(a / b))))));
	elseif (b <= 5.1e+147)
		tmp = Float64(1.0 / Float64(2.0 + Float64(b + t_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)
	t_0 = a * (-1.0 + (a * 0.5));
	tmp = 0.0;
	if (b <= -1.9e-179)
		tmp = 1.0 / (2.0 + t_0);
	elseif (b <= 6.4e-192)
		tmp = 1.0 / (b + (2.0 - (b * (a + (a / b)))));
	elseif (b <= 5.1e+147)
		tmp = 1.0 / (2.0 + (b + t_0));
	else
		tmp = 1.0 / (2.0 + (b * (1.0 + (b * 0.5))));
	end
	tmp_2 = tmp;
end
code[a_, b_] := Block[{t$95$0 = N[(a * N[(-1.0 + N[(a * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[b, -1.9e-179], N[(1.0 / N[(2.0 + t$95$0), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 6.4e-192], N[(1.0 / N[(b + N[(2.0 - N[(b * N[(a + N[(a / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 5.1e+147], N[(1.0 / N[(2.0 + N[(b + t$95$0), $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}
t_0 := a \cdot \left(-1 + a \cdot 0.5\right)\\
\mathbf{if}\;b \leq -1.9 \cdot 10^{-179}:\\
\;\;\;\;\frac{1}{2 + t\_0}\\

\mathbf{elif}\;b \leq 6.4 \cdot 10^{-192}:\\
\;\;\;\;\frac{1}{b + \left(2 - b \cdot \left(a + \frac{a}{b}\right)\right)}\\

\mathbf{elif}\;b \leq 5.1 \cdot 10^{+147}:\\
\;\;\;\;\frac{1}{2 + \left(b + t\_0\right)}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 4 regimes
  2. if b < -1.89999999999999987e-179

    1. Initial program 95.7%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity95.7%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/95.7%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/95.7%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg95.7%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg95.7%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub81.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity81.7%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/81.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      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. Taylor expanded in b around 0 29.9%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    6. Step-by-step derivation
      1. distribute-rgt1-in43.9%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp43.9%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/43.9%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. *-rgt-identity43.9%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{b + 1}}{e^{a}}} \]
      5. +-commutative43.9%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    7. Simplified43.9%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    8. Taylor expanded in a around 0 35.0%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + a \cdot \left(a \cdot \left(0.5 - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)}} \]
    9. Taylor expanded in b around 0 43.7%

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

    if -1.89999999999999987e-179 < b < 6.4000000000000003e-192

    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-sub66.0%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity66.0%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/66.0%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      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 78.0%

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

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

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

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

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{b + 1}}{e^{a}}} \]
      5. +-commutative100.0%

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

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    8. Taylor expanded in a around 0 67.9%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
    9. Step-by-step derivation
      1. associate-+r+67.9%

        \[\leadsto \frac{1}{\color{blue}{\left(2 + b\right) + -1 \cdot \left(a \cdot \left(1 + b\right)\right)}} \]
      2. +-commutative67.9%

        \[\leadsto \frac{1}{\color{blue}{\left(b + 2\right)} + -1 \cdot \left(a \cdot \left(1 + b\right)\right)} \]
      3. associate-+l+67.9%

        \[\leadsto \frac{1}{\color{blue}{b + \left(2 + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
      4. mul-1-neg67.9%

        \[\leadsto \frac{1}{b + \left(2 + \color{blue}{\left(-a \cdot \left(1 + b\right)\right)}\right)} \]
      5. distribute-rgt-neg-in67.9%

        \[\leadsto \frac{1}{b + \left(2 + \color{blue}{a \cdot \left(-\left(1 + b\right)\right)}\right)} \]
      6. distribute-neg-in67.9%

        \[\leadsto \frac{1}{b + \left(2 + a \cdot \color{blue}{\left(\left(-1\right) + \left(-b\right)\right)}\right)} \]
      7. metadata-eval67.9%

        \[\leadsto \frac{1}{b + \left(2 + a \cdot \left(\color{blue}{-1} + \left(-b\right)\right)\right)} \]
      8. unsub-neg67.9%

        \[\leadsto \frac{1}{b + \left(2 + a \cdot \color{blue}{\left(-1 - b\right)}\right)} \]
    10. Simplified67.9%

      \[\leadsto \frac{1}{\color{blue}{b + \left(2 + a \cdot \left(-1 - b\right)\right)}} \]
    11. Taylor expanded in b around inf 96.1%

      \[\leadsto \frac{1}{b + \left(2 + \color{blue}{b \cdot \left(-1 \cdot a + -1 \cdot \frac{a}{b}\right)}\right)} \]
    12. Step-by-step derivation
      1. mul-1-neg96.1%

        \[\leadsto \frac{1}{b + \left(2 + b \cdot \left(-1 \cdot a + \color{blue}{\left(-\frac{a}{b}\right)}\right)\right)} \]
      2. unsub-neg96.1%

        \[\leadsto \frac{1}{b + \left(2 + b \cdot \color{blue}{\left(-1 \cdot a - \frac{a}{b}\right)}\right)} \]
      3. mul-1-neg96.1%

        \[\leadsto \frac{1}{b + \left(2 + b \cdot \left(\color{blue}{\left(-a\right)} - \frac{a}{b}\right)\right)} \]
    13. Simplified96.1%

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

    if 6.4000000000000003e-192 < b < 5.09999999999999999e147

    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-sub61.8%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity61.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/61.8%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      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 84.8%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    6. Step-by-step derivation
      1. distribute-rgt1-in84.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp84.8%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/84.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. *-rgt-identity84.8%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{b + 1}}{e^{a}}} \]
      5. +-commutative84.8%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    7. Simplified84.8%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    8. Taylor expanded in a around 0 63.5%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + a \cdot \left(a \cdot \left(0.5 - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)}} \]
    9. Taylor expanded in b around 0 62.2%

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

    if 5.09999999999999999e147 < 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-sub62.2%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity62.2%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/62.2%

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

      \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
    6. Taylor expanded in b around 0 97.6%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -1.9 \cdot 10^{-179}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(-1 + a \cdot 0.5\right)}\\ \mathbf{elif}\;b \leq 6.4 \cdot 10^{-192}:\\ \;\;\;\;\frac{1}{b + \left(2 - b \cdot \left(a + \frac{a}{b}\right)\right)}\\ \mathbf{elif}\;b \leq 5.1 \cdot 10^{+147}:\\ \;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(-1 + a \cdot 0.5\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot 0.5\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 10: 72.0% accurate, 11.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -53:\\ \;\;\;\;0.5\\ \mathbf{elif}\;b \leq 6.5 \cdot 10^{+102}:\\ \;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(-1 + a \cdot \left(0.5 + a \cdot -0.16666666666666666\right)\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b -53.0)
   0.5
   (if (<= b 6.5e+102)
     (/
      1.0
      (+ 2.0 (+ b (* 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 <= -53.0) {
		tmp = 0.5;
	} else if (b <= 6.5e+102) {
		tmp = 1.0 / (2.0 + (b + (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 <= (-53.0d0)) then
        tmp = 0.5d0
    else if (b <= 6.5d+102) then
        tmp = 1.0d0 / (2.0d0 + (b + (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 <= -53.0) {
		tmp = 0.5;
	} else if (b <= 6.5e+102) {
		tmp = 1.0 / (2.0 + (b + (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 <= -53.0:
		tmp = 0.5
	elif b <= 6.5e+102:
		tmp = 1.0 / (2.0 + (b + (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 <= -53.0)
		tmp = 0.5;
	elseif (b <= 6.5e+102)
		tmp = Float64(1.0 / Float64(2.0 + Float64(b + 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 <= -53.0)
		tmp = 0.5;
	elseif (b <= 6.5e+102)
		tmp = 1.0 / (2.0 + (b + (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, -53.0], 0.5, If[LessEqual[b, 6.5e+102], N[(1.0 / N[(2.0 + N[(b + N[(a * N[(-1.0 + N[(a * N[(0.5 + N[(a * -0.16666666666666666), $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 -53:\\
\;\;\;\;0.5\\

\mathbf{elif}\;b \leq 6.5 \cdot 10^{+102}:\\
\;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(-1 + a \cdot \left(0.5 + a \cdot -0.16666666666666666\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 < -53

    1. Initial program 92.7%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity92.7%

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/92.7%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/92.7%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg92.7%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg92.7%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub92.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity92.7%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/92.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse96.4%

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

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg96.4%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg96.4%

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

      \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
    6. Taylor expanded in b around 0 18.8%

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

    if -53 < b < 6.5000000000000004e102

    1. Initial program 99.9%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Step-by-step derivation
      1. *-lft-identity99.9%

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

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/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-sub64.7%

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

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/64.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      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 79.4%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    6. Step-by-step derivation
      1. distribute-rgt1-in94.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp94.8%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/94.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. *-rgt-identity94.8%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{b + 1}}{e^{a}}} \]
      5. +-commutative94.8%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    7. Simplified94.8%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    8. Taylor expanded in a around 0 83.5%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(a \cdot \left(0.16666666666666666 + \left(-1 \cdot \left(-1 \cdot b + 0.5 \cdot b\right) + \left(-0.5 \cdot b + 0.16666666666666666 \cdot b\right)\right)\right)\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)}} \]
    9. Taylor expanded in b around inf 84.7%

      \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \color{blue}{\left(b \cdot \left(0.16666666666666666 \cdot a + 0.16666666666666666 \cdot \frac{a}{b}\right)\right)}\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
    10. Step-by-step derivation
      1. distribute-lft-out84.7%

        \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \left(b \cdot \color{blue}{\left(0.16666666666666666 \cdot \left(a + \frac{a}{b}\right)\right)}\right)\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
    11. Simplified84.7%

      \[\leadsto \frac{1}{2 + \left(b + a \cdot \left(a \cdot \left(\left(0.5 + -1 \cdot \color{blue}{\left(b \cdot \left(0.16666666666666666 \cdot \left(a + \frac{a}{b}\right)\right)\right)}\right) - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)} \]
    12. Taylor expanded in b around 0 83.5%

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

    if 6.5000000000000004e102 < 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%

      \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
    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 3 regimes into one program.
  4. Final simplification72.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -53:\\ \;\;\;\;0.5\\ \mathbf{elif}\;b \leq 6.5 \cdot 10^{+102}:\\ \;\;\;\;\frac{1}{2 + \left(b + a \cdot \left(-1 + a \cdot \left(0.5 + a \cdot -0.16666666666666666\right)\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot \left(0.5 + b \cdot 0.16666666666666666\right)\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 11: 64.5% accurate, 19.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 8 \cdot 10^{+146}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(-1 + a \cdot 0.5\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot 0.5\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b 8e+146)
   (/ 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 <= 8e+146) {
		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 <= 8d+146) 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 <= 8e+146) {
		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 <= 8e+146:
		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 <= 8e+146)
		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 <= 8e+146)
		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, 8e+146], 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 8 \cdot 10^{+146}:\\
\;\;\;\;\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 2 regimes
  2. if b < 7.99999999999999947e146

    1. Initial program 98.1%

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

        \[\leadsto \frac{\color{blue}{1 \cdot e^{a}}}{e^{a} + e^{b}} \]
      2. associate-*l/98.1%

        \[\leadsto \color{blue}{\frac{1}{e^{a} + e^{b}} \cdot e^{a}} \]
      3. associate-/r/98.2%

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      4. remove-double-neg98.2%

        \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
      5. unsub-neg98.2%

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub71.2%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity71.2%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/71.2%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      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-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 59.9%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    6. Step-by-step derivation
      1. distribute-rgt1-in70.9%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp70.9%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/70.9%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. *-rgt-identity70.9%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{b + 1}}{e^{a}}} \]
      5. +-commutative70.9%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    7. Simplified70.9%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    8. Taylor expanded in a around 0 55.9%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + a \cdot \left(a \cdot \left(0.5 - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)}} \]
    9. Taylor expanded in b around 0 58.9%

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

    if 7.99999999999999947e146 < 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-sub62.2%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity62.2%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/62.2%

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

      \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
    6. Taylor expanded in b around 0 97.6%

      \[\leadsto \frac{1}{\color{blue}{2 + b \cdot \left(1 + 0.5 \cdot b\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification64.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 8 \cdot 10^{+146}:\\ \;\;\;\;\frac{1}{2 + a \cdot \left(-1 + a \cdot 0.5\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2 + b \cdot \left(1 + b \cdot 0.5\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 12: 45.8% accurate, 21.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 3.2 \cdot 10^{-60}:\\ \;\;\;\;\frac{1}{2 - a}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b + \left(2 - b \cdot a\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b 3.2e-60) (/ 1.0 (- 2.0 a)) (/ 1.0 (+ b (- 2.0 (* b a))))))
double code(double a, double b) {
	double tmp;
	if (b <= 3.2e-60) {
		tmp = 1.0 / (2.0 - a);
	} else {
		tmp = 1.0 / (b + (2.0 - (b * a)));
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (b <= 3.2d-60) then
        tmp = 1.0d0 / (2.0d0 - a)
    else
        tmp = 1.0d0 / (b + (2.0d0 - (b * a)))
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (b <= 3.2e-60) {
		tmp = 1.0 / (2.0 - a);
	} else {
		tmp = 1.0 / (b + (2.0 - (b * a)));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= 3.2e-60:
		tmp = 1.0 / (2.0 - a)
	else:
		tmp = 1.0 / (b + (2.0 - (b * a)))
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= 3.2e-60)
		tmp = Float64(1.0 / Float64(2.0 - a));
	else
		tmp = Float64(1.0 / Float64(b + Float64(2.0 - Float64(b * a))));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= 3.2e-60)
		tmp = 1.0 / (2.0 - a);
	else
		tmp = 1.0 / (b + (2.0 - (b * a)));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, 3.2e-60], N[(1.0 / N[(2.0 - a), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(b + N[(2.0 - N[(b * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq 3.2 \cdot 10^{-60}:\\
\;\;\;\;\frac{1}{2 - a}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < 3.2000000000000001e-60

    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. remove-double-neg97.7%

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

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub75.8%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity75.8%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/75.8%

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

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg98.9%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg98.9%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg98.9%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
      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 57.2%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    6. Step-by-step derivation
      1. distribute-rgt1-in70.7%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp70.7%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/70.7%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. *-rgt-identity70.7%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{b + 1}}{e^{a}}} \]
      5. +-commutative70.7%

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

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    8. Taylor expanded in a around 0 48.2%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
    9. Step-by-step derivation
      1. associate-+r+48.2%

        \[\leadsto \frac{1}{\color{blue}{\left(2 + b\right) + -1 \cdot \left(a \cdot \left(1 + b\right)\right)}} \]
      2. +-commutative48.2%

        \[\leadsto \frac{1}{\color{blue}{\left(b + 2\right)} + -1 \cdot \left(a \cdot \left(1 + b\right)\right)} \]
      3. associate-+l+48.2%

        \[\leadsto \frac{1}{\color{blue}{b + \left(2 + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
      4. mul-1-neg48.2%

        \[\leadsto \frac{1}{b + \left(2 + \color{blue}{\left(-a \cdot \left(1 + b\right)\right)}\right)} \]
      5. distribute-rgt-neg-in48.2%

        \[\leadsto \frac{1}{b + \left(2 + \color{blue}{a \cdot \left(-\left(1 + b\right)\right)}\right)} \]
      6. distribute-neg-in48.2%

        \[\leadsto \frac{1}{b + \left(2 + a \cdot \color{blue}{\left(\left(-1\right) + \left(-b\right)\right)}\right)} \]
      7. metadata-eval48.2%

        \[\leadsto \frac{1}{b + \left(2 + a \cdot \left(\color{blue}{-1} + \left(-b\right)\right)\right)} \]
      8. unsub-neg48.2%

        \[\leadsto \frac{1}{b + \left(2 + a \cdot \color{blue}{\left(-1 - b\right)}\right)} \]
    10. Simplified48.2%

      \[\leadsto \frac{1}{\color{blue}{b + \left(2 + a \cdot \left(-1 - b\right)\right)}} \]
    11. Taylor expanded in b around 0 52.7%

      \[\leadsto \color{blue}{\frac{1}{2 + -1 \cdot a}} \]
    12. Step-by-step derivation
      1. mul-1-neg52.7%

        \[\leadsto \frac{1}{2 + \color{blue}{\left(-a\right)}} \]
      2. unsub-neg52.7%

        \[\leadsto \frac{1}{\color{blue}{2 - a}} \]
    13. Simplified52.7%

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

    if 3.2000000000000001e-60 < 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-sub56.4%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity56.4%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/56.4%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      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 57.8%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    6. Step-by-step derivation
      1. distribute-rgt1-in57.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp57.8%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/57.8%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. *-rgt-identity57.8%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{b + 1}}{e^{a}}} \]
      5. +-commutative57.8%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    7. Simplified57.8%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    8. Taylor expanded in a around 0 33.4%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
    9. Step-by-step derivation
      1. associate-+r+33.4%

        \[\leadsto \frac{1}{\color{blue}{\left(2 + b\right) + -1 \cdot \left(a \cdot \left(1 + b\right)\right)}} \]
      2. +-commutative33.4%

        \[\leadsto \frac{1}{\color{blue}{\left(b + 2\right)} + -1 \cdot \left(a \cdot \left(1 + b\right)\right)} \]
      3. associate-+l+33.4%

        \[\leadsto \frac{1}{\color{blue}{b + \left(2 + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
      4. mul-1-neg33.4%

        \[\leadsto \frac{1}{b + \left(2 + \color{blue}{\left(-a \cdot \left(1 + b\right)\right)}\right)} \]
      5. distribute-rgt-neg-in33.4%

        \[\leadsto \frac{1}{b + \left(2 + \color{blue}{a \cdot \left(-\left(1 + b\right)\right)}\right)} \]
      6. distribute-neg-in33.4%

        \[\leadsto \frac{1}{b + \left(2 + a \cdot \color{blue}{\left(\left(-1\right) + \left(-b\right)\right)}\right)} \]
      7. metadata-eval33.4%

        \[\leadsto \frac{1}{b + \left(2 + a \cdot \left(\color{blue}{-1} + \left(-b\right)\right)\right)} \]
      8. unsub-neg33.4%

        \[\leadsto \frac{1}{b + \left(2 + a \cdot \color{blue}{\left(-1 - b\right)}\right)} \]
    10. Simplified33.4%

      \[\leadsto \frac{1}{\color{blue}{b + \left(2 + a \cdot \left(-1 - b\right)\right)}} \]
    11. Taylor expanded in b around inf 33.1%

      \[\leadsto \frac{1}{b + \left(2 + \color{blue}{-1 \cdot \left(a \cdot b\right)}\right)} \]
    12. Step-by-step derivation
      1. associate-*r*33.1%

        \[\leadsto \frac{1}{b + \left(2 + \color{blue}{\left(-1 \cdot a\right) \cdot b}\right)} \]
      2. mul-1-neg33.1%

        \[\leadsto \frac{1}{b + \left(2 + \color{blue}{\left(-a\right)} \cdot b\right)} \]
    13. Simplified33.1%

      \[\leadsto \frac{1}{b + \left(2 + \color{blue}{\left(-a\right) \cdot b}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification46.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 3.2 \cdot 10^{-60}:\\ \;\;\;\;\frac{1}{2 - a}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{b + \left(2 - b \cdot a\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 13: 45.2% accurate, 25.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 2.75 \cdot 10^{-9}:\\ \;\;\;\;\frac{1}{2 - a}\\ \mathbf{else}:\\ \;\;\;\;\frac{-1}{a \cdot \left(1 + b\right)}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b 2.75e-9) (/ 1.0 (- 2.0 a)) (/ -1.0 (* a (+ 1.0 b)))))
double code(double a, double b) {
	double tmp;
	if (b <= 2.75e-9) {
		tmp = 1.0 / (2.0 - a);
	} else {
		tmp = -1.0 / (a * (1.0 + b));
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if (b <= 2.75d-9) then
        tmp = 1.0d0 / (2.0d0 - a)
    else
        tmp = (-1.0d0) / (a * (1.0d0 + b))
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if (b <= 2.75e-9) {
		tmp = 1.0 / (2.0 - a);
	} else {
		tmp = -1.0 / (a * (1.0 + b));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= 2.75e-9:
		tmp = 1.0 / (2.0 - a)
	else:
		tmp = -1.0 / (a * (1.0 + b))
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= 2.75e-9)
		tmp = Float64(1.0 / Float64(2.0 - a));
	else
		tmp = Float64(-1.0 / Float64(a * Float64(1.0 + b)));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= 2.75e-9)
		tmp = 1.0 / (2.0 - a);
	else
		tmp = -1.0 / (a * (1.0 + b));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, 2.75e-9], N[(1.0 / N[(2.0 - a), $MachinePrecision]), $MachinePrecision], N[(-1.0 / N[(a * N[(1.0 + b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq 2.75 \cdot 10^{-9}:\\
\;\;\;\;\frac{1}{2 - a}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < 2.7499999999999998e-9

    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. remove-double-neg97.9%

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

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
      6. div-sub74.2%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity74.2%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/74.2%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      9. lft-mult-inverse99.0%

        \[\leadsto \frac{1}{\color{blue}{1} - \frac{-e^{b}}{e^{a}}} \]
      10. sub-neg99.0%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-\frac{-e^{b}}{e^{a}}\right)}} \]
      11. distribute-frac-neg99.0%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{-\left(-e^{b}\right)}{e^{a}}}} \]
      12. remove-double-neg99.0%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{e^{b}}}{e^{a}}} \]
      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 60.7%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    6. Step-by-step derivation
      1. distribute-rgt1-in73.1%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp73.1%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/73.1%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. *-rgt-identity73.1%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{b + 1}}{e^{a}}} \]
      5. +-commutative73.1%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    7. Simplified73.1%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    8. Taylor expanded in a around 0 48.5%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
    9. Step-by-step derivation
      1. associate-+r+48.5%

        \[\leadsto \frac{1}{\color{blue}{\left(2 + b\right) + -1 \cdot \left(a \cdot \left(1 + b\right)\right)}} \]
      2. +-commutative48.5%

        \[\leadsto \frac{1}{\color{blue}{\left(b + 2\right)} + -1 \cdot \left(a \cdot \left(1 + b\right)\right)} \]
      3. associate-+l+48.5%

        \[\leadsto \frac{1}{\color{blue}{b + \left(2 + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
      4. mul-1-neg48.5%

        \[\leadsto \frac{1}{b + \left(2 + \color{blue}{\left(-a \cdot \left(1 + b\right)\right)}\right)} \]
      5. distribute-rgt-neg-in48.5%

        \[\leadsto \frac{1}{b + \left(2 + \color{blue}{a \cdot \left(-\left(1 + b\right)\right)}\right)} \]
      6. distribute-neg-in48.5%

        \[\leadsto \frac{1}{b + \left(2 + a \cdot \color{blue}{\left(\left(-1\right) + \left(-b\right)\right)}\right)} \]
      7. metadata-eval48.5%

        \[\leadsto \frac{1}{b + \left(2 + a \cdot \left(\color{blue}{-1} + \left(-b\right)\right)\right)} \]
      8. unsub-neg48.5%

        \[\leadsto \frac{1}{b + \left(2 + a \cdot \color{blue}{\left(-1 - b\right)}\right)} \]
    10. Simplified48.5%

      \[\leadsto \frac{1}{\color{blue}{b + \left(2 + a \cdot \left(-1 - b\right)\right)}} \]
    11. Taylor expanded in b around 0 52.4%

      \[\leadsto \color{blue}{\frac{1}{2 + -1 \cdot a}} \]
    12. Step-by-step derivation
      1. mul-1-neg52.4%

        \[\leadsto \frac{1}{2 + \color{blue}{\left(-a\right)}} \]
      2. unsub-neg52.4%

        \[\leadsto \frac{1}{\color{blue}{2 - a}} \]
    13. Simplified52.4%

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

    if 2.7499999999999998e-9 < 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-sub56.5%

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
      7. *-lft-identity56.5%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      8. associate-*l/56.5%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
      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 47.0%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
    6. Step-by-step derivation
      1. distribute-rgt1-in47.0%

        \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
      2. rec-exp47.0%

        \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
      3. associate-*r/47.0%

        \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
      4. *-rgt-identity47.0%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{b + 1}}{e^{a}}} \]
      5. +-commutative47.0%

        \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
    7. Simplified47.0%

      \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
    8. Taylor expanded in a around 0 28.7%

      \[\leadsto \frac{1}{\color{blue}{2 + \left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
    9. Step-by-step derivation
      1. associate-+r+28.7%

        \[\leadsto \frac{1}{\color{blue}{\left(2 + b\right) + -1 \cdot \left(a \cdot \left(1 + b\right)\right)}} \]
      2. +-commutative28.7%

        \[\leadsto \frac{1}{\color{blue}{\left(b + 2\right)} + -1 \cdot \left(a \cdot \left(1 + b\right)\right)} \]
      3. associate-+l+28.7%

        \[\leadsto \frac{1}{\color{blue}{b + \left(2 + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
      4. mul-1-neg28.7%

        \[\leadsto \frac{1}{b + \left(2 + \color{blue}{\left(-a \cdot \left(1 + b\right)\right)}\right)} \]
      5. distribute-rgt-neg-in28.7%

        \[\leadsto \frac{1}{b + \left(2 + \color{blue}{a \cdot \left(-\left(1 + b\right)\right)}\right)} \]
      6. distribute-neg-in28.7%

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

        \[\leadsto \frac{1}{b + \left(2 + a \cdot \left(\color{blue}{-1} + \left(-b\right)\right)\right)} \]
      8. unsub-neg28.7%

        \[\leadsto \frac{1}{b + \left(2 + a \cdot \color{blue}{\left(-1 - b\right)}\right)} \]
    10. Simplified28.7%

      \[\leadsto \frac{1}{\color{blue}{b + \left(2 + a \cdot \left(-1 - b\right)\right)}} \]
    11. Taylor expanded in a around inf 27.4%

      \[\leadsto \color{blue}{\frac{-1}{a \cdot \left(1 + b\right)}} \]
    12. Step-by-step derivation
      1. +-commutative27.4%

        \[\leadsto \frac{-1}{a \cdot \color{blue}{\left(b + 1\right)}} \]
    13. Simplified27.4%

      \[\leadsto \color{blue}{\frac{-1}{a \cdot \left(b + 1\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification46.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 2.75 \cdot 10^{-9}:\\ \;\;\;\;\frac{1}{2 - a}\\ \mathbf{else}:\\ \;\;\;\;\frac{-1}{a \cdot \left(1 + b\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 14: 53.7% accurate, 27.7× speedup?

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

\\
\frac{1}{2 + a \cdot \left(-1 + a \cdot 0.5\right)}
\end{array}
Derivation
  1. Initial program 98.4%

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

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

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

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

      \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
    5. unsub-neg98.4%

      \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
    6. div-sub69.9%

      \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
    7. *-lft-identity69.9%

      \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
    8. associate-*l/69.9%

      \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
    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. Taylor expanded in b around 0 57.4%

    \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
  6. Step-by-step derivation
    1. distribute-rgt1-in66.8%

      \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
    2. rec-exp66.8%

      \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
    3. associate-*r/66.8%

      \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
    4. *-rgt-identity66.8%

      \[\leadsto \frac{1}{1 + \frac{\color{blue}{b + 1}}{e^{a}}} \]
    5. +-commutative66.8%

      \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
  7. Simplified66.8%

    \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
  8. Taylor expanded in a around 0 53.9%

    \[\leadsto \frac{1}{\color{blue}{2 + \left(b + a \cdot \left(a \cdot \left(0.5 - \left(-1 \cdot b + 0.5 \cdot b\right)\right) - \left(1 + b\right)\right)\right)}} \]
  9. Taylor expanded in b around 0 54.0%

    \[\leadsto \color{blue}{\frac{1}{2 + a \cdot \left(0.5 \cdot a - 1\right)}} \]
  10. Final simplification54.0%

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

Alternative 15: 40.9% 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 98.4%

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

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

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

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

      \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
    5. unsub-neg98.4%

      \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
    6. div-sub69.9%

      \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
    7. *-lft-identity69.9%

      \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
    8. associate-*l/69.9%

      \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
    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. Taylor expanded in b around 0 57.4%

    \[\leadsto \frac{1}{\color{blue}{1 + \left(e^{-a} + b \cdot e^{-a}\right)}} \]
  6. Step-by-step derivation
    1. distribute-rgt1-in66.8%

      \[\leadsto \frac{1}{1 + \color{blue}{\left(b + 1\right) \cdot e^{-a}}} \]
    2. rec-exp66.8%

      \[\leadsto \frac{1}{1 + \left(b + 1\right) \cdot \color{blue}{\frac{1}{e^{a}}}} \]
    3. associate-*r/66.8%

      \[\leadsto \frac{1}{1 + \color{blue}{\frac{\left(b + 1\right) \cdot 1}{e^{a}}}} \]
    4. *-rgt-identity66.8%

      \[\leadsto \frac{1}{1 + \frac{\color{blue}{b + 1}}{e^{a}}} \]
    5. +-commutative66.8%

      \[\leadsto \frac{1}{1 + \frac{\color{blue}{1 + b}}{e^{a}}} \]
  7. Simplified66.8%

    \[\leadsto \frac{1}{\color{blue}{1 + \frac{1 + b}{e^{a}}}} \]
  8. Taylor expanded in a around 0 43.7%

    \[\leadsto \frac{1}{\color{blue}{2 + \left(b + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
  9. Step-by-step derivation
    1. associate-+r+43.7%

      \[\leadsto \frac{1}{\color{blue}{\left(2 + b\right) + -1 \cdot \left(a \cdot \left(1 + b\right)\right)}} \]
    2. +-commutative43.7%

      \[\leadsto \frac{1}{\color{blue}{\left(b + 2\right)} + -1 \cdot \left(a \cdot \left(1 + b\right)\right)} \]
    3. associate-+l+43.7%

      \[\leadsto \frac{1}{\color{blue}{b + \left(2 + -1 \cdot \left(a \cdot \left(1 + b\right)\right)\right)}} \]
    4. mul-1-neg43.7%

      \[\leadsto \frac{1}{b + \left(2 + \color{blue}{\left(-a \cdot \left(1 + b\right)\right)}\right)} \]
    5. distribute-rgt-neg-in43.7%

      \[\leadsto \frac{1}{b + \left(2 + \color{blue}{a \cdot \left(-\left(1 + b\right)\right)}\right)} \]
    6. distribute-neg-in43.7%

      \[\leadsto \frac{1}{b + \left(2 + a \cdot \color{blue}{\left(\left(-1\right) + \left(-b\right)\right)}\right)} \]
    7. metadata-eval43.7%

      \[\leadsto \frac{1}{b + \left(2 + a \cdot \left(\color{blue}{-1} + \left(-b\right)\right)\right)} \]
    8. unsub-neg43.7%

      \[\leadsto \frac{1}{b + \left(2 + a \cdot \color{blue}{\left(-1 - b\right)}\right)} \]
  10. Simplified43.7%

    \[\leadsto \frac{1}{\color{blue}{b + \left(2 + a \cdot \left(-1 - b\right)\right)}} \]
  11. Taylor expanded in b around 0 40.8%

    \[\leadsto \color{blue}{\frac{1}{2 + -1 \cdot a}} \]
  12. Step-by-step derivation
    1. mul-1-neg40.8%

      \[\leadsto \frac{1}{2 + \color{blue}{\left(-a\right)}} \]
    2. unsub-neg40.8%

      \[\leadsto \frac{1}{\color{blue}{2 - a}} \]
  13. Simplified40.8%

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

Alternative 16: 40.0% 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 98.4%

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

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

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

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

      \[\leadsto \frac{1}{\frac{e^{a} + \color{blue}{\left(-\left(-e^{b}\right)\right)}}{e^{a}}} \]
    5. unsub-neg98.4%

      \[\leadsto \frac{1}{\frac{\color{blue}{e^{a} - \left(-e^{b}\right)}}{e^{a}}} \]
    6. div-sub69.9%

      \[\leadsto \frac{1}{\color{blue}{\frac{e^{a}}{e^{a}} - \frac{-e^{b}}{e^{a}}}} \]
    7. *-lft-identity69.9%

      \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot e^{a}}}{e^{a}} - \frac{-e^{b}}{e^{a}}} \]
    8. associate-*l/69.9%

      \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a}} \cdot e^{a}} - \frac{-e^{b}}{e^{a}}} \]
    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. Taylor expanded in a around 0 80.9%

    \[\leadsto \frac{1}{\color{blue}{1 + e^{b}}} \]
  6. Taylor expanded in b around 0 40.0%

    \[\leadsto \color{blue}{0.5} \]
  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 2024089 
(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))))