Quotient of sum of exps

Percentage Accurate: 98.8% → 99.1%
Time: 5.5s
Alternatives: 13
Speedup: 1.0×

Specification

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

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

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 13 alternatives:

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

Initial Program: 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: 99.1% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{b} \leq 0.99997 \lor \neg \left(e^{b} \leq 1.0002\right):\\ \;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;{\left(e^{-a} + 1\right)}^{-1}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (or (<= (exp b) 0.99997) (not (<= (exp b) 1.0002)))
   (pow (+ (exp b) 1.0) -1.0)
   (pow (+ (exp (- a)) 1.0) -1.0)))
double code(double a, double b) {
	double tmp;
	if ((exp(b) <= 0.99997) || !(exp(b) <= 1.0002)) {
		tmp = pow((exp(b) + 1.0), -1.0);
	} else {
		tmp = pow((exp(-a) + 1.0), -1.0);
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: tmp
    if ((exp(b) <= 0.99997d0) .or. (.not. (exp(b) <= 1.0002d0))) then
        tmp = (exp(b) + 1.0d0) ** (-1.0d0)
    else
        tmp = (exp(-a) + 1.0d0) ** (-1.0d0)
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double tmp;
	if ((Math.exp(b) <= 0.99997) || !(Math.exp(b) <= 1.0002)) {
		tmp = Math.pow((Math.exp(b) + 1.0), -1.0);
	} else {
		tmp = Math.pow((Math.exp(-a) + 1.0), -1.0);
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if (math.exp(b) <= 0.99997) or not (math.exp(b) <= 1.0002):
		tmp = math.pow((math.exp(b) + 1.0), -1.0)
	else:
		tmp = math.pow((math.exp(-a) + 1.0), -1.0)
	return tmp
function code(a, b)
	tmp = 0.0
	if ((exp(b) <= 0.99997) || !(exp(b) <= 1.0002))
		tmp = Float64(exp(b) + 1.0) ^ -1.0;
	else
		tmp = Float64(exp(Float64(-a)) + 1.0) ^ -1.0;
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if ((exp(b) <= 0.99997) || ~((exp(b) <= 1.0002)))
		tmp = (exp(b) + 1.0) ^ -1.0;
	else
		tmp = (exp(-a) + 1.0) ^ -1.0;
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[Or[LessEqual[N[Exp[b], $MachinePrecision], 0.99997], N[Not[LessEqual[N[Exp[b], $MachinePrecision], 1.0002]], $MachinePrecision]], N[Power[N[(N[Exp[b], $MachinePrecision] + 1.0), $MachinePrecision], -1.0], $MachinePrecision], N[Power[N[(N[Exp[(-a)], $MachinePrecision] + 1.0), $MachinePrecision], -1.0], $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;e^{b} \leq 0.99997 \lor \neg \left(e^{b} \leq 1.0002\right):\\
\;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (exp.f64 b) < 0.99997000000000003 or 1.0002 < (exp.f64 b)

    1. Initial program 98.4%

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

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

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

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

        \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
      4. lower-exp.f6499.2

        \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
    5. Applied rewrites99.2%

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

    if 0.99997000000000003 < (exp.f64 b) < 1.0002

    1. Initial program 99.2%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. unpow1N/A

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

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

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

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

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

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
      7. lift-exp.f64N/A

        \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
      8. rec-expN/A

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

        \[\leadsto \frac{\frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
      10. lower-neg.f6499.2

        \[\leadsto \frac{\frac{1}{e^{\color{blue}{-a}}}}{e^{a} + e^{b}} \]
    4. Applied rewrites99.2%

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

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

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

        \[\leadsto \frac{\frac{1}{\color{blue}{e^{-a}}}}{e^{a} + e^{b}} \]
      4. lift-neg.f64N/A

        \[\leadsto \frac{\frac{1}{e^{\color{blue}{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
      5. exp-negN/A

        \[\leadsto \frac{\frac{1}{\color{blue}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
      6. lift-exp.f64N/A

        \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
      7. remove-double-divN/A

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

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

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      10. div-invN/A

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

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot e^{b} + e^{-a} \cdot e^{a}}} \]
    6. Applied rewrites99.9%

      \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(e^{-a}, e^{b}, 1\right)}} \]
    7. Taylor expanded in b around 0

      \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
    8. Step-by-step derivation
      1. +-commutativeN/A

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

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

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

        \[\leadsto \frac{1}{\color{blue}{e^{-1 \cdot a}} + 1} \]
      5. neg-mul-1N/A

        \[\leadsto \frac{1}{e^{\color{blue}{\mathsf{neg}\left(a\right)}} + 1} \]
      6. lower-neg.f6499.6

        \[\leadsto \frac{1}{e^{\color{blue}{-a}} + 1} \]
    9. Applied rewrites99.6%

      \[\leadsto \frac{1}{\color{blue}{e^{-a} + 1}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;e^{b} \leq 0.99997 \lor \neg \left(e^{b} \leq 1.0002\right):\\ \;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;{\left(e^{-a} + 1\right)}^{-1}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 99.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ {\left(\mathsf{fma}\left(e^{-a}, e^{b}, 1\right)\right)}^{-1} \end{array} \]
(FPCore (a b) :precision binary64 (pow (fma (exp (- a)) (exp b) 1.0) -1.0))
double code(double a, double b) {
	return pow(fma(exp(-a), exp(b), 1.0), -1.0);
}
function code(a, b)
	return fma(exp(Float64(-a)), exp(b), 1.0) ^ -1.0
end
code[a_, b_] := N[Power[N[(N[Exp[(-a)], $MachinePrecision] * N[Exp[b], $MachinePrecision] + 1.0), $MachinePrecision], -1.0], $MachinePrecision]
\begin{array}{l}

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

    \[\frac{e^{a}}{e^{a} + e^{b}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. unpow1N/A

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

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

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

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

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

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
    7. lift-exp.f64N/A

      \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
    8. rec-expN/A

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

      \[\leadsto \frac{\frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
    10. lower-neg.f6498.8

      \[\leadsto \frac{\frac{1}{e^{\color{blue}{-a}}}}{e^{a} + e^{b}} \]
  4. Applied rewrites98.8%

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

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

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

      \[\leadsto \frac{\frac{1}{\color{blue}{e^{-a}}}}{e^{a} + e^{b}} \]
    4. lift-neg.f64N/A

      \[\leadsto \frac{\frac{1}{e^{\color{blue}{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
    5. exp-negN/A

      \[\leadsto \frac{\frac{1}{\color{blue}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
    6. lift-exp.f64N/A

      \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
    7. remove-double-divN/A

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

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

      \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
    10. div-invN/A

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

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

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

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

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

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

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

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

      \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot e^{b} + e^{-a} \cdot e^{a}}} \]
  6. Applied rewrites99.2%

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

    \[\leadsto {\left(\mathsf{fma}\left(e^{-a}, e^{b}, 1\right)\right)}^{-1} \]
  8. Add Preprocessing

Alternative 3: 53.9% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{b} \leq 1.0002:\\ \;\;\;\;{\left(2 - a\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= (exp b) 1.0002)
   (pow (- 2.0 a) -1.0)
   (pow (fma (fma 0.5 b 1.0) b 2.0) -1.0)))
double code(double a, double b) {
	double tmp;
	if (exp(b) <= 1.0002) {
		tmp = pow((2.0 - a), -1.0);
	} else {
		tmp = pow(fma(fma(0.5, b, 1.0), b, 2.0), -1.0);
	}
	return tmp;
}
function code(a, b)
	tmp = 0.0
	if (exp(b) <= 1.0002)
		tmp = Float64(2.0 - a) ^ -1.0;
	else
		tmp = fma(fma(0.5, b, 1.0), b, 2.0) ^ -1.0;
	end
	return tmp
end
code[a_, b_] := If[LessEqual[N[Exp[b], $MachinePrecision], 1.0002], N[Power[N[(2.0 - a), $MachinePrecision], -1.0], $MachinePrecision], N[Power[N[(N[(0.5 * b + 1.0), $MachinePrecision] * b + 2.0), $MachinePrecision], -1.0], $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;e^{b} \leq 1.0002:\\
\;\;\;\;{\left(2 - a\right)}^{-1}\\

\mathbf{else}:\\
\;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), b, 2\right)\right)}^{-1}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (exp.f64 b) < 1.0002

    1. Initial program 98.4%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. unpow1N/A

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

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

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

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

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

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
      7. lift-exp.f64N/A

        \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
      8. rec-expN/A

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

        \[\leadsto \frac{\frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
      10. lower-neg.f6498.4

        \[\leadsto \frac{\frac{1}{e^{\color{blue}{-a}}}}{e^{a} + e^{b}} \]
    4. Applied rewrites98.4%

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

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

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

        \[\leadsto \frac{\frac{1}{\color{blue}{e^{-a}}}}{e^{a} + e^{b}} \]
      4. lift-neg.f64N/A

        \[\leadsto \frac{\frac{1}{e^{\color{blue}{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
      5. exp-negN/A

        \[\leadsto \frac{\frac{1}{\color{blue}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
      6. lift-exp.f64N/A

        \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
      7. remove-double-divN/A

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

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

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
      10. div-invN/A

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

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot e^{b} + e^{-a} \cdot e^{a}}} \]
    6. Applied rewrites98.9%

      \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(e^{-a}, e^{b}, 1\right)}} \]
    7. Taylor expanded in b around 0

      \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
    8. Step-by-step derivation
      1. +-commutativeN/A

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

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

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

        \[\leadsto \frac{1}{\color{blue}{e^{-1 \cdot a}} + 1} \]
      5. neg-mul-1N/A

        \[\leadsto \frac{1}{e^{\color{blue}{\mathsf{neg}\left(a\right)}} + 1} \]
      6. lower-neg.f6478.5

        \[\leadsto \frac{1}{e^{\color{blue}{-a}} + 1} \]
    9. Applied rewrites78.5%

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

      \[\leadsto \frac{1}{2 + \color{blue}{-1 \cdot a}} \]
    11. Step-by-step derivation
      1. Applied rewrites51.0%

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

      if 1.0002 < (exp.f64 b)

      1. Initial program 100.0%

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
      7. Step-by-step derivation
        1. Applied rewrites55.9%

          \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), \color{blue}{b}, 2\right)} \]
      8. Recombined 2 regimes into one program.
      9. Final simplification52.4%

        \[\leadsto \begin{array}{l} \mathbf{if}\;e^{b} \leq 1.0002:\\ \;\;\;\;{\left(2 - a\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \]
      10. Add Preprocessing

      Alternative 4: 98.4% accurate, 1.5× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -45000000:\\ \;\;\;\;\frac{e^{a}}{2}\\ \mathbf{else}:\\ \;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\ \end{array} \end{array} \]
      (FPCore (a b)
       :precision binary64
       (if (<= a -45000000.0) (/ (exp a) 2.0) (pow (+ (exp b) 1.0) -1.0)))
      double code(double a, double b) {
      	double tmp;
      	if (a <= -45000000.0) {
      		tmp = exp(a) / 2.0;
      	} else {
      		tmp = pow((exp(b) + 1.0), -1.0);
      	}
      	return tmp;
      }
      
      real(8) function code(a, b)
          real(8), intent (in) :: a
          real(8), intent (in) :: b
          real(8) :: tmp
          if (a <= (-45000000.0d0)) then
              tmp = exp(a) / 2.0d0
          else
              tmp = (exp(b) + 1.0d0) ** (-1.0d0)
          end if
          code = tmp
      end function
      
      public static double code(double a, double b) {
      	double tmp;
      	if (a <= -45000000.0) {
      		tmp = Math.exp(a) / 2.0;
      	} else {
      		tmp = Math.pow((Math.exp(b) + 1.0), -1.0);
      	}
      	return tmp;
      }
      
      def code(a, b):
      	tmp = 0
      	if a <= -45000000.0:
      		tmp = math.exp(a) / 2.0
      	else:
      		tmp = math.pow((math.exp(b) + 1.0), -1.0)
      	return tmp
      
      function code(a, b)
      	tmp = 0.0
      	if (a <= -45000000.0)
      		tmp = Float64(exp(a) / 2.0);
      	else
      		tmp = Float64(exp(b) + 1.0) ^ -1.0;
      	end
      	return tmp
      end
      
      function tmp_2 = code(a, b)
      	tmp = 0.0;
      	if (a <= -45000000.0)
      		tmp = exp(a) / 2.0;
      	else
      		tmp = (exp(b) + 1.0) ^ -1.0;
      	end
      	tmp_2 = tmp;
      end
      
      code[a_, b_] := If[LessEqual[a, -45000000.0], N[(N[Exp[a], $MachinePrecision] / 2.0), $MachinePrecision], N[Power[N[(N[Exp[b], $MachinePrecision] + 1.0), $MachinePrecision], -1.0], $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;a \leq -45000000:\\
      \;\;\;\;\frac{e^{a}}{2}\\
      
      \mathbf{else}:\\
      \;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if a < -4.5e7

        1. Initial program 98.5%

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

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

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

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

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

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

          \[\leadsto \frac{e^{a}}{2} \]
        7. Step-by-step derivation
          1. Applied rewrites100.0%

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

          if -4.5e7 < a

          1. Initial program 98.9%

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

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

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

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

              \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
            4. lower-exp.f6496.3

              \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
          5. Applied rewrites96.3%

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

          \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -45000000:\\ \;\;\;\;\frac{e^{a}}{2}\\ \mathbf{else}:\\ \;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\ \end{array} \]
        10. Add Preprocessing

        Alternative 5: 70.7% accurate, 2.5× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 1.4 \cdot 10^{+56}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.16666666666666666, a, 0.5\right), a, -1\right), a, 2\right)\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666 \cdot b, b, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \end{array} \]
        (FPCore (a b)
         :precision binary64
         (if (<= b 1.4e+56)
           (pow (fma (fma (fma -0.16666666666666666 a 0.5) a -1.0) a 2.0) -1.0)
           (pow (fma (fma (* 0.16666666666666666 b) b 1.0) b 2.0) -1.0)))
        double code(double a, double b) {
        	double tmp;
        	if (b <= 1.4e+56) {
        		tmp = pow(fma(fma(fma(-0.16666666666666666, a, 0.5), a, -1.0), a, 2.0), -1.0);
        	} else {
        		tmp = pow(fma(fma((0.16666666666666666 * b), b, 1.0), b, 2.0), -1.0);
        	}
        	return tmp;
        }
        
        function code(a, b)
        	tmp = 0.0
        	if (b <= 1.4e+56)
        		tmp = fma(fma(fma(-0.16666666666666666, a, 0.5), a, -1.0), a, 2.0) ^ -1.0;
        	else
        		tmp = fma(fma(Float64(0.16666666666666666 * b), b, 1.0), b, 2.0) ^ -1.0;
        	end
        	return tmp
        end
        
        code[a_, b_] := If[LessEqual[b, 1.4e+56], N[Power[N[(N[(N[(-0.16666666666666666 * a + 0.5), $MachinePrecision] * a + -1.0), $MachinePrecision] * a + 2.0), $MachinePrecision], -1.0], $MachinePrecision], N[Power[N[(N[(N[(0.16666666666666666 * b), $MachinePrecision] * b + 1.0), $MachinePrecision] * b + 2.0), $MachinePrecision], -1.0], $MachinePrecision]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;b \leq 1.4 \cdot 10^{+56}:\\
        \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.16666666666666666, a, 0.5\right), a, -1\right), a, 2\right)\right)}^{-1}\\
        
        \mathbf{else}:\\
        \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666 \cdot b, b, 1\right), b, 2\right)\right)}^{-1}\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if b < 1.40000000000000004e56

          1. Initial program 98.4%

            \[\frac{e^{a}}{e^{a} + e^{b}} \]
          2. Add Preprocessing
          3. Step-by-step derivation
            1. unpow1N/A

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

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

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

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

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

              \[\leadsto \frac{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
            7. lift-exp.f64N/A

              \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
            8. rec-expN/A

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

              \[\leadsto \frac{\frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
            10. lower-neg.f6498.4

              \[\leadsto \frac{\frac{1}{e^{\color{blue}{-a}}}}{e^{a} + e^{b}} \]
          4. Applied rewrites98.4%

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

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

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

              \[\leadsto \frac{\frac{1}{\color{blue}{e^{-a}}}}{e^{a} + e^{b}} \]
            4. lift-neg.f64N/A

              \[\leadsto \frac{\frac{1}{e^{\color{blue}{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
            5. exp-negN/A

              \[\leadsto \frac{\frac{1}{\color{blue}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
            6. lift-exp.f64N/A

              \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
            7. remove-double-divN/A

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

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

              \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
            10. div-invN/A

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

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

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

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

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

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

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

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

              \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot e^{b} + e^{-a} \cdot e^{a}}} \]
          6. Applied rewrites98.9%

            \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(e^{-a}, e^{b}, 1\right)}} \]
          7. Taylor expanded in b around 0

            \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
          8. Step-by-step derivation
            1. +-commutativeN/A

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

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

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

              \[\leadsto \frac{1}{\color{blue}{e^{-1 \cdot a}} + 1} \]
            5. neg-mul-1N/A

              \[\leadsto \frac{1}{e^{\color{blue}{\mathsf{neg}\left(a\right)}} + 1} \]
            6. lower-neg.f6477.8

              \[\leadsto \frac{1}{e^{\color{blue}{-a}} + 1} \]
          9. Applied rewrites77.8%

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

            \[\leadsto \frac{1}{2 + \color{blue}{a \cdot \left(a \cdot \left(\frac{1}{2} + \frac{-1}{6} \cdot a\right) - 1\right)}} \]
          11. Step-by-step derivation
            1. Applied rewrites70.1%

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

            if 1.40000000000000004e56 < b

            1. Initial program 100.0%

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

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

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

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

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

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

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

              \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + b \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot b\right)\right)}} \]
            7. Step-by-step derivation
              1. Applied rewrites86.6%

                \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), \color{blue}{b}, 2\right)} \]
              2. Taylor expanded in b around inf

                \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{6} \cdot b, b, 1\right), b, 2\right)} \]
              3. Step-by-step derivation
                1. Applied rewrites86.6%

                  \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666 \cdot b, b, 1\right), b, 2\right)} \]
              4. Recombined 2 regimes into one program.
              5. Final simplification74.1%

                \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 1.4 \cdot 10^{+56}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.16666666666666666, a, 0.5\right), a, -1\right), a, 2\right)\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666 \cdot b, b, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \]
              6. Add Preprocessing

              Alternative 6: 76.3% accurate, 2.5× speedup?

              \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 1.76 \cdot 10^{+61}:\\ \;\;\;\;\frac{e^{a}}{2}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666 \cdot b, b, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \end{array} \]
              (FPCore (a b)
               :precision binary64
               (if (<= b 1.76e+61)
                 (/ (exp a) 2.0)
                 (pow (fma (fma (* 0.16666666666666666 b) b 1.0) b 2.0) -1.0)))
              double code(double a, double b) {
              	double tmp;
              	if (b <= 1.76e+61) {
              		tmp = exp(a) / 2.0;
              	} else {
              		tmp = pow(fma(fma((0.16666666666666666 * b), b, 1.0), b, 2.0), -1.0);
              	}
              	return tmp;
              }
              
              function code(a, b)
              	tmp = 0.0
              	if (b <= 1.76e+61)
              		tmp = Float64(exp(a) / 2.0);
              	else
              		tmp = fma(fma(Float64(0.16666666666666666 * b), b, 1.0), b, 2.0) ^ -1.0;
              	end
              	return tmp
              end
              
              code[a_, b_] := If[LessEqual[b, 1.76e+61], N[(N[Exp[a], $MachinePrecision] / 2.0), $MachinePrecision], N[Power[N[(N[(N[(0.16666666666666666 * b), $MachinePrecision] * b + 1.0), $MachinePrecision] * b + 2.0), $MachinePrecision], -1.0], $MachinePrecision]]
              
              \begin{array}{l}
              
              \\
              \begin{array}{l}
              \mathbf{if}\;b \leq 1.76 \cdot 10^{+61}:\\
              \;\;\;\;\frac{e^{a}}{2}\\
              
              \mathbf{else}:\\
              \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666 \cdot b, b, 1\right), b, 2\right)\right)}^{-1}\\
              
              
              \end{array}
              \end{array}
              
              Derivation
              1. Split input into 2 regimes
              2. if b < 1.75999999999999997e61

                1. Initial program 98.5%

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

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

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

                    \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                  3. lower-exp.f6476.6

                    \[\leadsto \frac{e^{a}}{\color{blue}{e^{a}} + 1} \]
                5. Applied rewrites76.6%

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

                  \[\leadsto \frac{e^{a}}{2} \]
                7. Step-by-step derivation
                  1. Applied rewrites72.9%

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

                  if 1.75999999999999997e61 < b

                  1. Initial program 100.0%

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

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

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

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

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

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

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

                    \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + b \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot b\right)\right)}} \]
                  7. Step-by-step derivation
                    1. Applied rewrites90.7%

                      \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), \color{blue}{b}, 2\right)} \]
                    2. Taylor expanded in b around inf

                      \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{6} \cdot b, b, 1\right), b, 2\right)} \]
                    3. Step-by-step derivation
                      1. Applied rewrites90.7%

                        \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666 \cdot b, b, 1\right), b, 2\right)} \]
                    4. Recombined 2 regimes into one program.
                    5. Final simplification77.1%

                      \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 1.76 \cdot 10^{+61}:\\ \;\;\;\;\frac{e^{a}}{2}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666 \cdot b, b, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \]
                    6. Add Preprocessing

                    Alternative 7: 67.7% accurate, 2.5× speedup?

                    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 1.4 \cdot 10^{+56}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, -1\right), a, 1\right) + 1\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666 \cdot b, b, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \end{array} \]
                    (FPCore (a b)
                     :precision binary64
                     (if (<= b 1.4e+56)
                       (pow (+ (fma (fma 0.5 a -1.0) a 1.0) 1.0) -1.0)
                       (pow (fma (fma (* 0.16666666666666666 b) b 1.0) b 2.0) -1.0)))
                    double code(double a, double b) {
                    	double tmp;
                    	if (b <= 1.4e+56) {
                    		tmp = pow((fma(fma(0.5, a, -1.0), a, 1.0) + 1.0), -1.0);
                    	} else {
                    		tmp = pow(fma(fma((0.16666666666666666 * b), b, 1.0), b, 2.0), -1.0);
                    	}
                    	return tmp;
                    }
                    
                    function code(a, b)
                    	tmp = 0.0
                    	if (b <= 1.4e+56)
                    		tmp = Float64(fma(fma(0.5, a, -1.0), a, 1.0) + 1.0) ^ -1.0;
                    	else
                    		tmp = fma(fma(Float64(0.16666666666666666 * b), b, 1.0), b, 2.0) ^ -1.0;
                    	end
                    	return tmp
                    end
                    
                    code[a_, b_] := If[LessEqual[b, 1.4e+56], N[Power[N[(N[(N[(0.5 * a + -1.0), $MachinePrecision] * a + 1.0), $MachinePrecision] + 1.0), $MachinePrecision], -1.0], $MachinePrecision], N[Power[N[(N[(N[(0.16666666666666666 * b), $MachinePrecision] * b + 1.0), $MachinePrecision] * b + 2.0), $MachinePrecision], -1.0], $MachinePrecision]]
                    
                    \begin{array}{l}
                    
                    \\
                    \begin{array}{l}
                    \mathbf{if}\;b \leq 1.4 \cdot 10^{+56}:\\
                    \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, -1\right), a, 1\right) + 1\right)}^{-1}\\
                    
                    \mathbf{else}:\\
                    \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666 \cdot b, b, 1\right), b, 2\right)\right)}^{-1}\\
                    
                    
                    \end{array}
                    \end{array}
                    
                    Derivation
                    1. Split input into 2 regimes
                    2. if b < 1.40000000000000004e56

                      1. Initial program 98.4%

                        \[\frac{e^{a}}{e^{a} + e^{b}} \]
                      2. Add Preprocessing
                      3. Step-by-step derivation
                        1. unpow1N/A

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

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

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

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

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

                          \[\leadsto \frac{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
                        7. lift-exp.f64N/A

                          \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
                        8. rec-expN/A

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

                          \[\leadsto \frac{\frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
                        10. lower-neg.f6498.4

                          \[\leadsto \frac{\frac{1}{e^{\color{blue}{-a}}}}{e^{a} + e^{b}} \]
                      4. Applied rewrites98.4%

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

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

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

                          \[\leadsto \frac{\frac{1}{\color{blue}{e^{-a}}}}{e^{a} + e^{b}} \]
                        4. lift-neg.f64N/A

                          \[\leadsto \frac{\frac{1}{e^{\color{blue}{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
                        5. exp-negN/A

                          \[\leadsto \frac{\frac{1}{\color{blue}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
                        6. lift-exp.f64N/A

                          \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
                        7. remove-double-divN/A

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

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

                          \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                        10. div-invN/A

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

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

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

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

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

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

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

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

                          \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot e^{b} + e^{-a} \cdot e^{a}}} \]
                      6. Applied rewrites98.9%

                        \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(e^{-a}, e^{b}, 1\right)}} \]
                      7. Taylor expanded in b around 0

                        \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                      8. Step-by-step derivation
                        1. +-commutativeN/A

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

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

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

                          \[\leadsto \frac{1}{\color{blue}{e^{-1 \cdot a}} + 1} \]
                        5. neg-mul-1N/A

                          \[\leadsto \frac{1}{e^{\color{blue}{\mathsf{neg}\left(a\right)}} + 1} \]
                        6. lower-neg.f6477.8

                          \[\leadsto \frac{1}{e^{\color{blue}{-a}} + 1} \]
                      9. Applied rewrites77.8%

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

                        \[\leadsto \frac{1}{\left(1 + a \cdot \left(\frac{1}{2} \cdot a - 1\right)\right) + 1} \]
                      11. Step-by-step derivation
                        1. Applied rewrites67.1%

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

                        if 1.40000000000000004e56 < b

                        1. Initial program 100.0%

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

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

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

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

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

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

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

                          \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + b \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot b\right)\right)}} \]
                        7. Step-by-step derivation
                          1. Applied rewrites86.6%

                            \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), \color{blue}{b}, 2\right)} \]
                          2. Taylor expanded in b around inf

                            \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{6} \cdot b, b, 1\right), b, 2\right)} \]
                          3. Step-by-step derivation
                            1. Applied rewrites86.6%

                              \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666 \cdot b, b, 1\right), b, 2\right)} \]
                          4. Recombined 2 regimes into one program.
                          5. Final simplification71.9%

                            \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 1.4 \cdot 10^{+56}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, -1\right), a, 1\right) + 1\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666 \cdot b, b, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \]
                          6. Add Preprocessing

                          Alternative 8: 67.7% accurate, 2.5× speedup?

                          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 1.4 \cdot 10^{+56}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, -1\right), a, 1\right) + 1\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right) \cdot \left(b \cdot b\right)\right)}^{-1}\\ \end{array} \end{array} \]
                          (FPCore (a b)
                           :precision binary64
                           (if (<= b 1.4e+56)
                             (pow (+ (fma (fma 0.5 a -1.0) a 1.0) 1.0) -1.0)
                             (pow (* (fma 0.16666666666666666 b 0.5) (* b b)) -1.0)))
                          double code(double a, double b) {
                          	double tmp;
                          	if (b <= 1.4e+56) {
                          		tmp = pow((fma(fma(0.5, a, -1.0), a, 1.0) + 1.0), -1.0);
                          	} else {
                          		tmp = pow((fma(0.16666666666666666, b, 0.5) * (b * b)), -1.0);
                          	}
                          	return tmp;
                          }
                          
                          function code(a, b)
                          	tmp = 0.0
                          	if (b <= 1.4e+56)
                          		tmp = Float64(fma(fma(0.5, a, -1.0), a, 1.0) + 1.0) ^ -1.0;
                          	else
                          		tmp = Float64(fma(0.16666666666666666, b, 0.5) * Float64(b * b)) ^ -1.0;
                          	end
                          	return tmp
                          end
                          
                          code[a_, b_] := If[LessEqual[b, 1.4e+56], N[Power[N[(N[(N[(0.5 * a + -1.0), $MachinePrecision] * a + 1.0), $MachinePrecision] + 1.0), $MachinePrecision], -1.0], $MachinePrecision], N[Power[N[(N[(0.16666666666666666 * b + 0.5), $MachinePrecision] * N[(b * b), $MachinePrecision]), $MachinePrecision], -1.0], $MachinePrecision]]
                          
                          \begin{array}{l}
                          
                          \\
                          \begin{array}{l}
                          \mathbf{if}\;b \leq 1.4 \cdot 10^{+56}:\\
                          \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, -1\right), a, 1\right) + 1\right)}^{-1}\\
                          
                          \mathbf{else}:\\
                          \;\;\;\;{\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right) \cdot \left(b \cdot b\right)\right)}^{-1}\\
                          
                          
                          \end{array}
                          \end{array}
                          
                          Derivation
                          1. Split input into 2 regimes
                          2. if b < 1.40000000000000004e56

                            1. Initial program 98.4%

                              \[\frac{e^{a}}{e^{a} + e^{b}} \]
                            2. Add Preprocessing
                            3. Step-by-step derivation
                              1. unpow1N/A

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

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

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

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

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

                                \[\leadsto \frac{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
                              7. lift-exp.f64N/A

                                \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
                              8. rec-expN/A

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

                                \[\leadsto \frac{\frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
                              10. lower-neg.f6498.4

                                \[\leadsto \frac{\frac{1}{e^{\color{blue}{-a}}}}{e^{a} + e^{b}} \]
                            4. Applied rewrites98.4%

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

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

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

                                \[\leadsto \frac{\frac{1}{\color{blue}{e^{-a}}}}{e^{a} + e^{b}} \]
                              4. lift-neg.f64N/A

                                \[\leadsto \frac{\frac{1}{e^{\color{blue}{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
                              5. exp-negN/A

                                \[\leadsto \frac{\frac{1}{\color{blue}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
                              6. lift-exp.f64N/A

                                \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
                              7. remove-double-divN/A

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

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

                                \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                              10. div-invN/A

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

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

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

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

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

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

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

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

                                \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot e^{b} + e^{-a} \cdot e^{a}}} \]
                            6. Applied rewrites98.9%

                              \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(e^{-a}, e^{b}, 1\right)}} \]
                            7. Taylor expanded in b around 0

                              \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                            8. Step-by-step derivation
                              1. +-commutativeN/A

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

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

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

                                \[\leadsto \frac{1}{\color{blue}{e^{-1 \cdot a}} + 1} \]
                              5. neg-mul-1N/A

                                \[\leadsto \frac{1}{e^{\color{blue}{\mathsf{neg}\left(a\right)}} + 1} \]
                              6. lower-neg.f6477.8

                                \[\leadsto \frac{1}{e^{\color{blue}{-a}} + 1} \]
                            9. Applied rewrites77.8%

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

                              \[\leadsto \frac{1}{\left(1 + a \cdot \left(\frac{1}{2} \cdot a - 1\right)\right) + 1} \]
                            11. Step-by-step derivation
                              1. Applied rewrites67.1%

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

                              if 1.40000000000000004e56 < b

                              1. Initial program 100.0%

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

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

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

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

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

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

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

                                \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + b \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot b\right)\right)}} \]
                              7. Step-by-step derivation
                                1. Applied rewrites86.6%

                                  \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), \color{blue}{b}, 2\right)} \]
                                2. Taylor expanded in b around inf

                                  \[\leadsto \frac{1}{{b}^{3} \cdot \left(\frac{1}{6} + \color{blue}{\frac{1}{2} \cdot \frac{1}{b}}\right)} \]
                                3. Step-by-step derivation
                                  1. Applied rewrites86.6%

                                    \[\leadsto \frac{1}{\mathsf{fma}\left(0.16666666666666666, b, 0.5\right) \cdot \left(b \cdot \color{blue}{b}\right)} \]
                                4. Recombined 2 regimes into one program.
                                5. Final simplification71.9%

                                  \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 1.4 \cdot 10^{+56}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, -1\right), a, 1\right) + 1\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right) \cdot \left(b \cdot b\right)\right)}^{-1}\\ \end{array} \]
                                6. Add Preprocessing

                                Alternative 9: 64.4% accurate, 2.6× speedup?

                                \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 1.15 \cdot 10^{+154}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, -1\right), a, 1\right) + 1\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(0.5 \cdot b\right) \cdot b\right)}^{-1}\\ \end{array} \end{array} \]
                                (FPCore (a b)
                                 :precision binary64
                                 (if (<= b 1.15e+154)
                                   (pow (+ (fma (fma 0.5 a -1.0) a 1.0) 1.0) -1.0)
                                   (pow (* (* 0.5 b) b) -1.0)))
                                double code(double a, double b) {
                                	double tmp;
                                	if (b <= 1.15e+154) {
                                		tmp = pow((fma(fma(0.5, a, -1.0), a, 1.0) + 1.0), -1.0);
                                	} else {
                                		tmp = pow(((0.5 * b) * b), -1.0);
                                	}
                                	return tmp;
                                }
                                
                                function code(a, b)
                                	tmp = 0.0
                                	if (b <= 1.15e+154)
                                		tmp = Float64(fma(fma(0.5, a, -1.0), a, 1.0) + 1.0) ^ -1.0;
                                	else
                                		tmp = Float64(Float64(0.5 * b) * b) ^ -1.0;
                                	end
                                	return tmp
                                end
                                
                                code[a_, b_] := If[LessEqual[b, 1.15e+154], N[Power[N[(N[(N[(0.5 * a + -1.0), $MachinePrecision] * a + 1.0), $MachinePrecision] + 1.0), $MachinePrecision], -1.0], $MachinePrecision], N[Power[N[(N[(0.5 * b), $MachinePrecision] * b), $MachinePrecision], -1.0], $MachinePrecision]]
                                
                                \begin{array}{l}
                                
                                \\
                                \begin{array}{l}
                                \mathbf{if}\;b \leq 1.15 \cdot 10^{+154}:\\
                                \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, -1\right), a, 1\right) + 1\right)}^{-1}\\
                                
                                \mathbf{else}:\\
                                \;\;\;\;{\left(\left(0.5 \cdot b\right) \cdot b\right)}^{-1}\\
                                
                                
                                \end{array}
                                \end{array}
                                
                                Derivation
                                1. Split input into 2 regimes
                                2. if b < 1.15e154

                                  1. Initial program 98.6%

                                    \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                  2. Add Preprocessing
                                  3. Step-by-step derivation
                                    1. unpow1N/A

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

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

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

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

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

                                      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
                                    7. lift-exp.f64N/A

                                      \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
                                    8. rec-expN/A

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

                                      \[\leadsto \frac{\frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
                                    10. lower-neg.f6498.6

                                      \[\leadsto \frac{\frac{1}{e^{\color{blue}{-a}}}}{e^{a} + e^{b}} \]
                                  4. Applied rewrites98.6%

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

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

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

                                      \[\leadsto \frac{\frac{1}{\color{blue}{e^{-a}}}}{e^{a} + e^{b}} \]
                                    4. lift-neg.f64N/A

                                      \[\leadsto \frac{\frac{1}{e^{\color{blue}{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
                                    5. exp-negN/A

                                      \[\leadsto \frac{\frac{1}{\color{blue}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
                                    6. lift-exp.f64N/A

                                      \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
                                    7. remove-double-divN/A

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

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

                                      \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                    10. div-invN/A

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

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

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

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

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

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

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

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

                                      \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot e^{b} + e^{-a} \cdot e^{a}}} \]
                                  6. Applied rewrites99.0%

                                    \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(e^{-a}, e^{b}, 1\right)}} \]
                                  7. Taylor expanded in b around 0

                                    \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                                  8. Step-by-step derivation
                                    1. +-commutativeN/A

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

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

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

                                      \[\leadsto \frac{1}{\color{blue}{e^{-1 \cdot a}} + 1} \]
                                    5. neg-mul-1N/A

                                      \[\leadsto \frac{1}{e^{\color{blue}{\mathsf{neg}\left(a\right)}} + 1} \]
                                    6. lower-neg.f6472.8

                                      \[\leadsto \frac{1}{e^{\color{blue}{-a}} + 1} \]
                                  9. Applied rewrites72.8%

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

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

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

                                    if 1.15e154 < b

                                    1. Initial program 100.0%

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

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

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

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

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

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

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

                                      \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                    7. Step-by-step derivation
                                      1. Applied rewrites100.0%

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

                                        \[\leadsto \frac{1}{\frac{1}{2} \cdot {b}^{\color{blue}{2}}} \]
                                      3. Step-by-step derivation
                                        1. Applied rewrites100.0%

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

                                        \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 1.15 \cdot 10^{+154}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, -1\right), a, 1\right) + 1\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(0.5 \cdot b\right) \cdot b\right)}^{-1}\\ \end{array} \]
                                      6. Add Preprocessing

                                      Alternative 10: 64.4% accurate, 2.6× speedup?

                                      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 1.15 \cdot 10^{+154}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, -1\right), a, 2\right)\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(0.5 \cdot b\right) \cdot b\right)}^{-1}\\ \end{array} \end{array} \]
                                      (FPCore (a b)
                                       :precision binary64
                                       (if (<= b 1.15e+154)
                                         (pow (fma (fma 0.5 a -1.0) a 2.0) -1.0)
                                         (pow (* (* 0.5 b) b) -1.0)))
                                      double code(double a, double b) {
                                      	double tmp;
                                      	if (b <= 1.15e+154) {
                                      		tmp = pow(fma(fma(0.5, a, -1.0), a, 2.0), -1.0);
                                      	} else {
                                      		tmp = pow(((0.5 * b) * b), -1.0);
                                      	}
                                      	return tmp;
                                      }
                                      
                                      function code(a, b)
                                      	tmp = 0.0
                                      	if (b <= 1.15e+154)
                                      		tmp = fma(fma(0.5, a, -1.0), a, 2.0) ^ -1.0;
                                      	else
                                      		tmp = Float64(Float64(0.5 * b) * b) ^ -1.0;
                                      	end
                                      	return tmp
                                      end
                                      
                                      code[a_, b_] := If[LessEqual[b, 1.15e+154], N[Power[N[(N[(0.5 * a + -1.0), $MachinePrecision] * a + 2.0), $MachinePrecision], -1.0], $MachinePrecision], N[Power[N[(N[(0.5 * b), $MachinePrecision] * b), $MachinePrecision], -1.0], $MachinePrecision]]
                                      
                                      \begin{array}{l}
                                      
                                      \\
                                      \begin{array}{l}
                                      \mathbf{if}\;b \leq 1.15 \cdot 10^{+154}:\\
                                      \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, -1\right), a, 2\right)\right)}^{-1}\\
                                      
                                      \mathbf{else}:\\
                                      \;\;\;\;{\left(\left(0.5 \cdot b\right) \cdot b\right)}^{-1}\\
                                      
                                      
                                      \end{array}
                                      \end{array}
                                      
                                      Derivation
                                      1. Split input into 2 regimes
                                      2. if b < 1.15e154

                                        1. Initial program 98.6%

                                          \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                        2. Add Preprocessing
                                        3. Step-by-step derivation
                                          1. unpow1N/A

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

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

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

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

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

                                            \[\leadsto \frac{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
                                          7. lift-exp.f64N/A

                                            \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
                                          8. rec-expN/A

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

                                            \[\leadsto \frac{\frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
                                          10. lower-neg.f6498.6

                                            \[\leadsto \frac{\frac{1}{e^{\color{blue}{-a}}}}{e^{a} + e^{b}} \]
                                        4. Applied rewrites98.6%

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

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

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

                                            \[\leadsto \frac{\frac{1}{\color{blue}{e^{-a}}}}{e^{a} + e^{b}} \]
                                          4. lift-neg.f64N/A

                                            \[\leadsto \frac{\frac{1}{e^{\color{blue}{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
                                          5. exp-negN/A

                                            \[\leadsto \frac{\frac{1}{\color{blue}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
                                          6. lift-exp.f64N/A

                                            \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
                                          7. remove-double-divN/A

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

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

                                            \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                          10. div-invN/A

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

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

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

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

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

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

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

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

                                            \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot e^{b} + e^{-a} \cdot e^{a}}} \]
                                        6. Applied rewrites99.0%

                                          \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(e^{-a}, e^{b}, 1\right)}} \]
                                        7. Taylor expanded in b around 0

                                          \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                                        8. Step-by-step derivation
                                          1. +-commutativeN/A

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

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

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

                                            \[\leadsto \frac{1}{\color{blue}{e^{-1 \cdot a}} + 1} \]
                                          5. neg-mul-1N/A

                                            \[\leadsto \frac{1}{e^{\color{blue}{\mathsf{neg}\left(a\right)}} + 1} \]
                                          6. lower-neg.f6472.8

                                            \[\leadsto \frac{1}{e^{\color{blue}{-a}} + 1} \]
                                        9. Applied rewrites72.8%

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

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

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

                                          if 1.15e154 < b

                                          1. Initial program 100.0%

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

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

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

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

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

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

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

                                            \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                          7. Step-by-step derivation
                                            1. Applied rewrites100.0%

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

                                              \[\leadsto \frac{1}{\frac{1}{2} \cdot {b}^{\color{blue}{2}}} \]
                                            3. Step-by-step derivation
                                              1. Applied rewrites100.0%

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

                                              \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 1.15 \cdot 10^{+154}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, -1\right), a, 2\right)\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(0.5 \cdot b\right) \cdot b\right)}^{-1}\\ \end{array} \]
                                            6. Add Preprocessing

                                            Alternative 11: 53.8% accurate, 2.7× speedup?

                                            \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 2.4 \cdot 10^{+53}:\\ \;\;\;\;{\left(2 - a\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(0.5 \cdot b\right) \cdot b\right)}^{-1}\\ \end{array} \end{array} \]
                                            (FPCore (a b)
                                             :precision binary64
                                             (if (<= b 2.4e+53) (pow (- 2.0 a) -1.0) (pow (* (* 0.5 b) b) -1.0)))
                                            double code(double a, double b) {
                                            	double tmp;
                                            	if (b <= 2.4e+53) {
                                            		tmp = pow((2.0 - a), -1.0);
                                            	} else {
                                            		tmp = pow(((0.5 * b) * b), -1.0);
                                            	}
                                            	return tmp;
                                            }
                                            
                                            real(8) function code(a, b)
                                                real(8), intent (in) :: a
                                                real(8), intent (in) :: b
                                                real(8) :: tmp
                                                if (b <= 2.4d+53) then
                                                    tmp = (2.0d0 - a) ** (-1.0d0)
                                                else
                                                    tmp = ((0.5d0 * b) * b) ** (-1.0d0)
                                                end if
                                                code = tmp
                                            end function
                                            
                                            public static double code(double a, double b) {
                                            	double tmp;
                                            	if (b <= 2.4e+53) {
                                            		tmp = Math.pow((2.0 - a), -1.0);
                                            	} else {
                                            		tmp = Math.pow(((0.5 * b) * b), -1.0);
                                            	}
                                            	return tmp;
                                            }
                                            
                                            def code(a, b):
                                            	tmp = 0
                                            	if b <= 2.4e+53:
                                            		tmp = math.pow((2.0 - a), -1.0)
                                            	else:
                                            		tmp = math.pow(((0.5 * b) * b), -1.0)
                                            	return tmp
                                            
                                            function code(a, b)
                                            	tmp = 0.0
                                            	if (b <= 2.4e+53)
                                            		tmp = Float64(2.0 - a) ^ -1.0;
                                            	else
                                            		tmp = Float64(Float64(0.5 * b) * b) ^ -1.0;
                                            	end
                                            	return tmp
                                            end
                                            
                                            function tmp_2 = code(a, b)
                                            	tmp = 0.0;
                                            	if (b <= 2.4e+53)
                                            		tmp = (2.0 - a) ^ -1.0;
                                            	else
                                            		tmp = ((0.5 * b) * b) ^ -1.0;
                                            	end
                                            	tmp_2 = tmp;
                                            end
                                            
                                            code[a_, b_] := If[LessEqual[b, 2.4e+53], N[Power[N[(2.0 - a), $MachinePrecision], -1.0], $MachinePrecision], N[Power[N[(N[(0.5 * b), $MachinePrecision] * b), $MachinePrecision], -1.0], $MachinePrecision]]
                                            
                                            \begin{array}{l}
                                            
                                            \\
                                            \begin{array}{l}
                                            \mathbf{if}\;b \leq 2.4 \cdot 10^{+53}:\\
                                            \;\;\;\;{\left(2 - a\right)}^{-1}\\
                                            
                                            \mathbf{else}:\\
                                            \;\;\;\;{\left(\left(0.5 \cdot b\right) \cdot b\right)}^{-1}\\
                                            
                                            
                                            \end{array}
                                            \end{array}
                                            
                                            Derivation
                                            1. Split input into 2 regimes
                                            2. if b < 2.4e53

                                              1. Initial program 98.4%

                                                \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                              2. Add Preprocessing
                                              3. Step-by-step derivation
                                                1. unpow1N/A

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

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

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

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

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

                                                  \[\leadsto \frac{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
                                                7. lift-exp.f64N/A

                                                  \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
                                                8. rec-expN/A

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

                                                  \[\leadsto \frac{\frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
                                                10. lower-neg.f6498.4

                                                  \[\leadsto \frac{\frac{1}{e^{\color{blue}{-a}}}}{e^{a} + e^{b}} \]
                                              4. Applied rewrites98.4%

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

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

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

                                                  \[\leadsto \frac{\frac{1}{\color{blue}{e^{-a}}}}{e^{a} + e^{b}} \]
                                                4. lift-neg.f64N/A

                                                  \[\leadsto \frac{\frac{1}{e^{\color{blue}{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
                                                5. exp-negN/A

                                                  \[\leadsto \frac{\frac{1}{\color{blue}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
                                                6. lift-exp.f64N/A

                                                  \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
                                                7. remove-double-divN/A

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

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

                                                  \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                10. div-invN/A

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

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

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

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

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

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

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

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

                                                  \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot e^{b} + e^{-a} \cdot e^{a}}} \]
                                              6. Applied rewrites98.9%

                                                \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(e^{-a}, e^{b}, 1\right)}} \]
                                              7. Taylor expanded in b around 0

                                                \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                                              8. Step-by-step derivation
                                                1. +-commutativeN/A

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

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

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

                                                  \[\leadsto \frac{1}{\color{blue}{e^{-1 \cdot a}} + 1} \]
                                                5. neg-mul-1N/A

                                                  \[\leadsto \frac{1}{e^{\color{blue}{\mathsf{neg}\left(a\right)}} + 1} \]
                                                6. lower-neg.f6477.8

                                                  \[\leadsto \frac{1}{e^{\color{blue}{-a}} + 1} \]
                                              9. Applied rewrites77.8%

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

                                                \[\leadsto \frac{1}{2 + \color{blue}{-1 \cdot a}} \]
                                              11. Step-by-step derivation
                                                1. Applied rewrites48.8%

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

                                                if 2.4e53 < b

                                                1. Initial program 100.0%

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

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

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

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

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

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

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

                                                  \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                                7. Step-by-step derivation
                                                  1. Applied rewrites63.0%

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

                                                    \[\leadsto \frac{1}{\frac{1}{2} \cdot {b}^{\color{blue}{2}}} \]
                                                  3. Step-by-step derivation
                                                    1. Applied rewrites63.0%

                                                      \[\leadsto \frac{1}{\left(0.5 \cdot b\right) \cdot b} \]
                                                  4. Recombined 2 regimes into one program.
                                                  5. Final simplification52.3%

                                                    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 2.4 \cdot 10^{+53}:\\ \;\;\;\;{\left(2 - a\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(0.5 \cdot b\right) \cdot b\right)}^{-1}\\ \end{array} \]
                                                  6. Add Preprocessing

                                                  Alternative 12: 41.0% accurate, 3.0× speedup?

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

                                                    \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                  2. Add Preprocessing
                                                  3. Step-by-step derivation
                                                    1. unpow1N/A

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

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

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

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

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

                                                      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
                                                    7. lift-exp.f64N/A

                                                      \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
                                                    8. rec-expN/A

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

                                                      \[\leadsto \frac{\frac{1}{\color{blue}{e^{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
                                                    10. lower-neg.f6498.8

                                                      \[\leadsto \frac{\frac{1}{e^{\color{blue}{-a}}}}{e^{a} + e^{b}} \]
                                                  4. Applied rewrites98.8%

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

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

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

                                                      \[\leadsto \frac{\frac{1}{\color{blue}{e^{-a}}}}{e^{a} + e^{b}} \]
                                                    4. lift-neg.f64N/A

                                                      \[\leadsto \frac{\frac{1}{e^{\color{blue}{\mathsf{neg}\left(a\right)}}}}{e^{a} + e^{b}} \]
                                                    5. exp-negN/A

                                                      \[\leadsto \frac{\frac{1}{\color{blue}{\frac{1}{e^{a}}}}}{e^{a} + e^{b}} \]
                                                    6. lift-exp.f64N/A

                                                      \[\leadsto \frac{\frac{1}{\frac{1}{\color{blue}{e^{a}}}}}{e^{a} + e^{b}} \]
                                                    7. remove-double-divN/A

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

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

                                                      \[\leadsto \color{blue}{\frac{1}{\frac{e^{a} + e^{b}}{e^{a}}}} \]
                                                    10. div-invN/A

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

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

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

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

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

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

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

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

                                                      \[\leadsto \frac{1}{\color{blue}{e^{-a} \cdot e^{b} + e^{-a} \cdot e^{a}}} \]
                                                  6. Applied rewrites99.2%

                                                    \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(e^{-a}, e^{b}, 1\right)}} \]
                                                  7. Taylor expanded in b around 0

                                                    \[\leadsto \frac{1}{\color{blue}{1 + e^{\mathsf{neg}\left(a\right)}}} \]
                                                  8. Step-by-step derivation
                                                    1. +-commutativeN/A

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

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

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

                                                      \[\leadsto \frac{1}{\color{blue}{e^{-1 \cdot a}} + 1} \]
                                                    5. neg-mul-1N/A

                                                      \[\leadsto \frac{1}{e^{\color{blue}{\mathsf{neg}\left(a\right)}} + 1} \]
                                                    6. lower-neg.f6465.8

                                                      \[\leadsto \frac{1}{e^{\color{blue}{-a}} + 1} \]
                                                  9. Applied rewrites65.8%

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

                                                    \[\leadsto \frac{1}{2 + \color{blue}{-1 \cdot a}} \]
                                                  11. Step-by-step derivation
                                                    1. Applied rewrites37.7%

                                                      \[\leadsto \frac{1}{2 - \color{blue}{a}} \]
                                                    2. Final simplification37.7%

                                                      \[\leadsto {\left(2 - a\right)}^{-1} \]
                                                    3. Add Preprocessing

                                                    Alternative 13: 40.2% accurate, 315.0× speedup?

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

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

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

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

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

                                                        \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                      4. lower-exp.f6479.9

                                                        \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
                                                    5. Applied rewrites79.9%

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

                                                      \[\leadsto \frac{1}{2} \]
                                                    7. Step-by-step derivation
                                                      1. Applied rewrites36.8%

                                                        \[\leadsto 0.5 \]
                                                      2. Add Preprocessing

                                                      Developer Target 1: 100.0% accurate, 2.7× speedup?

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

                                                      Reproduce

                                                      ?
                                                      herbie shell --seed 2024322 
                                                      (FPCore (a b)
                                                        :name "Quotient of sum of exps"
                                                        :precision binary64
                                                      
                                                        :alt
                                                        (! :herbie-platform default (/ 1 (+ 1 (exp (- b a)))))
                                                      
                                                        (/ (exp a) (+ (exp a) (exp b))))