expq2 (section 3.11)

Percentage Accurate: 37.9% → 100.0%
Time: 8.5s
Alternatives: 8
Speedup: 68.3×

Specification

?
\[710 > x\]
\[\begin{array}{l} \\ \frac{e^{x}}{e^{x} - 1} \end{array} \]
(FPCore (x) :precision binary64 (/ (exp x) (- (exp x) 1.0)))
double code(double x) {
	return exp(x) / (exp(x) - 1.0);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = exp(x) / (exp(x) - 1.0d0)
end function
public static double code(double x) {
	return Math.exp(x) / (Math.exp(x) - 1.0);
}
def code(x):
	return math.exp(x) / (math.exp(x) - 1.0)
function code(x)
	return Float64(exp(x) / Float64(exp(x) - 1.0))
end
function tmp = code(x)
	tmp = exp(x) / (exp(x) - 1.0);
end
code[x_] := N[(N[Exp[x], $MachinePrecision] / N[(N[Exp[x], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{e^{x}}{e^{x} - 1}
\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 8 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: 37.9% accurate, 1.0× speedup?

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

\\
\frac{e^{x}}{e^{x} - 1}
\end{array}

Alternative 1: 100.0% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \frac{-1}{\mathsf{expm1}\left(-x\right)} \end{array} \]
(FPCore (x) :precision binary64 (/ -1.0 (expm1 (- x))))
double code(double x) {
	return -1.0 / expm1(-x);
}
public static double code(double x) {
	return -1.0 / Math.expm1(-x);
}
def code(x):
	return -1.0 / math.expm1(-x)
function code(x)
	return Float64(-1.0 / expm1(Float64(-x)))
end
code[x_] := N[(-1.0 / N[(Exp[(-x)] - 1), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-1}{\mathsf{expm1}\left(-x\right)}
\end{array}
Derivation
  1. Initial program 33.3%

    \[\frac{e^{x}}{e^{x} - 1} \]
  2. Step-by-step derivation
    1. sub-neg33.3%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} + \left(-1\right)}} \]
    2. +-commutative33.3%

      \[\leadsto \frac{e^{x}}{\color{blue}{\left(-1\right) + e^{x}}} \]
    3. rgt-mult-inverse6.8%

      \[\leadsto \frac{e^{x}}{\left(-\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}\right) + e^{x}} \]
    4. exp-neg6.8%

      \[\leadsto \frac{e^{x}}{\left(-e^{x} \cdot \color{blue}{e^{-x}}\right) + e^{x}} \]
    5. distribute-rgt-neg-out6.8%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(-e^{-x}\right)} + e^{x}} \]
    6. *-rgt-identity6.8%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(-e^{-x}\right) + \color{blue}{e^{x} \cdot 1}} \]
    7. distribute-lft-in6.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(\left(-e^{-x}\right) + 1\right)}} \]
    8. neg-sub06.7%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(\color{blue}{\left(0 - e^{-x}\right)} + 1\right)} \]
    9. associate-+l-6.7%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(0 - \left(e^{-x} - 1\right)\right)}} \]
    10. neg-sub06.1%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(-\left(e^{-x} - 1\right)\right)}} \]
    11. associate-/r*6.1%

      \[\leadsto \color{blue}{\frac{\frac{e^{x}}{e^{x}}}{-\left(e^{-x} - 1\right)}} \]
    12. *-rgt-identity6.1%

      \[\leadsto \frac{\frac{\color{blue}{e^{x} \cdot 1}}{e^{x}}}{-\left(e^{-x} - 1\right)} \]
    13. associate-*r/6.1%

      \[\leadsto \frac{\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}}{-\left(e^{-x} - 1\right)} \]
    14. rgt-mult-inverse32.7%

      \[\leadsto \frac{\color{blue}{1}}{-\left(e^{-x} - 1\right)} \]
    15. distribute-frac-neg232.7%

      \[\leadsto \color{blue}{-\frac{1}{e^{-x} - 1}} \]
    16. distribute-neg-frac32.7%

      \[\leadsto \color{blue}{\frac{-1}{e^{-x} - 1}} \]
    17. metadata-eval32.7%

      \[\leadsto \frac{\color{blue}{-1}}{e^{-x} - 1} \]
    18. expm1-define100.0%

      \[\leadsto \frac{-1}{\color{blue}{\mathsf{expm1}\left(-x\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{-1}{\mathsf{expm1}\left(-x\right)}} \]
  4. Add Preprocessing
  5. Final simplification100.0%

    \[\leadsto \frac{-1}{\mathsf{expm1}\left(-x\right)} \]
  6. Add Preprocessing

Alternative 2: 91.3% accurate, 12.1× speedup?

\[\begin{array}{l} \\ \frac{-1}{x \cdot \left(-1 + x \cdot \left(0.5 + x \cdot \left(x \cdot 0.041666666666666664 - 0.16666666666666666\right)\right)\right)} \end{array} \]
(FPCore (x)
 :precision binary64
 (/
  -1.0
  (*
   x
   (+
    -1.0
    (* x (+ 0.5 (* x (- (* x 0.041666666666666664) 0.16666666666666666))))))))
double code(double x) {
	return -1.0 / (x * (-1.0 + (x * (0.5 + (x * ((x * 0.041666666666666664) - 0.16666666666666666))))));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (-1.0d0) / (x * ((-1.0d0) + (x * (0.5d0 + (x * ((x * 0.041666666666666664d0) - 0.16666666666666666d0))))))
end function
public static double code(double x) {
	return -1.0 / (x * (-1.0 + (x * (0.5 + (x * ((x * 0.041666666666666664) - 0.16666666666666666))))));
}
def code(x):
	return -1.0 / (x * (-1.0 + (x * (0.5 + (x * ((x * 0.041666666666666664) - 0.16666666666666666))))))
function code(x)
	return Float64(-1.0 / Float64(x * Float64(-1.0 + Float64(x * Float64(0.5 + Float64(x * Float64(Float64(x * 0.041666666666666664) - 0.16666666666666666)))))))
end
function tmp = code(x)
	tmp = -1.0 / (x * (-1.0 + (x * (0.5 + (x * ((x * 0.041666666666666664) - 0.16666666666666666))))));
end
code[x_] := N[(-1.0 / N[(x * N[(-1.0 + N[(x * N[(0.5 + N[(x * N[(N[(x * 0.041666666666666664), $MachinePrecision] - 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-1}{x \cdot \left(-1 + x \cdot \left(0.5 + x \cdot \left(x \cdot 0.041666666666666664 - 0.16666666666666666\right)\right)\right)}
\end{array}
Derivation
  1. Initial program 33.3%

    \[\frac{e^{x}}{e^{x} - 1} \]
  2. Step-by-step derivation
    1. sub-neg33.3%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} + \left(-1\right)}} \]
    2. +-commutative33.3%

      \[\leadsto \frac{e^{x}}{\color{blue}{\left(-1\right) + e^{x}}} \]
    3. rgt-mult-inverse6.8%

      \[\leadsto \frac{e^{x}}{\left(-\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}\right) + e^{x}} \]
    4. exp-neg6.8%

      \[\leadsto \frac{e^{x}}{\left(-e^{x} \cdot \color{blue}{e^{-x}}\right) + e^{x}} \]
    5. distribute-rgt-neg-out6.8%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(-e^{-x}\right)} + e^{x}} \]
    6. *-rgt-identity6.8%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(-e^{-x}\right) + \color{blue}{e^{x} \cdot 1}} \]
    7. distribute-lft-in6.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(\left(-e^{-x}\right) + 1\right)}} \]
    8. neg-sub06.7%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(\color{blue}{\left(0 - e^{-x}\right)} + 1\right)} \]
    9. associate-+l-6.7%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(0 - \left(e^{-x} - 1\right)\right)}} \]
    10. neg-sub06.1%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(-\left(e^{-x} - 1\right)\right)}} \]
    11. associate-/r*6.1%

      \[\leadsto \color{blue}{\frac{\frac{e^{x}}{e^{x}}}{-\left(e^{-x} - 1\right)}} \]
    12. *-rgt-identity6.1%

      \[\leadsto \frac{\frac{\color{blue}{e^{x} \cdot 1}}{e^{x}}}{-\left(e^{-x} - 1\right)} \]
    13. associate-*r/6.1%

      \[\leadsto \frac{\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}}{-\left(e^{-x} - 1\right)} \]
    14. rgt-mult-inverse32.7%

      \[\leadsto \frac{\color{blue}{1}}{-\left(e^{-x} - 1\right)} \]
    15. distribute-frac-neg232.7%

      \[\leadsto \color{blue}{-\frac{1}{e^{-x} - 1}} \]
    16. distribute-neg-frac32.7%

      \[\leadsto \color{blue}{\frac{-1}{e^{-x} - 1}} \]
    17. metadata-eval32.7%

      \[\leadsto \frac{\color{blue}{-1}}{e^{-x} - 1} \]
    18. expm1-define100.0%

      \[\leadsto \frac{-1}{\color{blue}{\mathsf{expm1}\left(-x\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{-1}{\mathsf{expm1}\left(-x\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 92.5%

    \[\leadsto \frac{-1}{\color{blue}{x \cdot \left(x \cdot \left(0.5 + x \cdot \left(0.041666666666666664 \cdot x - 0.16666666666666666\right)\right) - 1\right)}} \]
  6. Final simplification92.5%

    \[\leadsto \frac{-1}{x \cdot \left(-1 + x \cdot \left(0.5 + x \cdot \left(x \cdot 0.041666666666666664 - 0.16666666666666666\right)\right)\right)} \]
  7. Add Preprocessing

Alternative 3: 88.7% accurate, 15.8× speedup?

\[\begin{array}{l} \\ \frac{-1}{x \cdot \left(-1 + x \cdot \left(0.5 + x \cdot -0.16666666666666666\right)\right)} \end{array} \]
(FPCore (x)
 :precision binary64
 (/ -1.0 (* x (+ -1.0 (* x (+ 0.5 (* x -0.16666666666666666)))))))
double code(double x) {
	return -1.0 / (x * (-1.0 + (x * (0.5 + (x * -0.16666666666666666)))));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (-1.0d0) / (x * ((-1.0d0) + (x * (0.5d0 + (x * (-0.16666666666666666d0))))))
end function
public static double code(double x) {
	return -1.0 / (x * (-1.0 + (x * (0.5 + (x * -0.16666666666666666)))));
}
def code(x):
	return -1.0 / (x * (-1.0 + (x * (0.5 + (x * -0.16666666666666666)))))
function code(x)
	return Float64(-1.0 / Float64(x * Float64(-1.0 + Float64(x * Float64(0.5 + Float64(x * -0.16666666666666666))))))
end
function tmp = code(x)
	tmp = -1.0 / (x * (-1.0 + (x * (0.5 + (x * -0.16666666666666666)))));
end
code[x_] := N[(-1.0 / N[(x * N[(-1.0 + N[(x * N[(0.5 + N[(x * -0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-1}{x \cdot \left(-1 + x \cdot \left(0.5 + x \cdot -0.16666666666666666\right)\right)}
\end{array}
Derivation
  1. Initial program 33.3%

    \[\frac{e^{x}}{e^{x} - 1} \]
  2. Step-by-step derivation
    1. sub-neg33.3%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} + \left(-1\right)}} \]
    2. +-commutative33.3%

      \[\leadsto \frac{e^{x}}{\color{blue}{\left(-1\right) + e^{x}}} \]
    3. rgt-mult-inverse6.8%

      \[\leadsto \frac{e^{x}}{\left(-\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}\right) + e^{x}} \]
    4. exp-neg6.8%

      \[\leadsto \frac{e^{x}}{\left(-e^{x} \cdot \color{blue}{e^{-x}}\right) + e^{x}} \]
    5. distribute-rgt-neg-out6.8%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(-e^{-x}\right)} + e^{x}} \]
    6. *-rgt-identity6.8%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(-e^{-x}\right) + \color{blue}{e^{x} \cdot 1}} \]
    7. distribute-lft-in6.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(\left(-e^{-x}\right) + 1\right)}} \]
    8. neg-sub06.7%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(\color{blue}{\left(0 - e^{-x}\right)} + 1\right)} \]
    9. associate-+l-6.7%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(0 - \left(e^{-x} - 1\right)\right)}} \]
    10. neg-sub06.1%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(-\left(e^{-x} - 1\right)\right)}} \]
    11. associate-/r*6.1%

      \[\leadsto \color{blue}{\frac{\frac{e^{x}}{e^{x}}}{-\left(e^{-x} - 1\right)}} \]
    12. *-rgt-identity6.1%

      \[\leadsto \frac{\frac{\color{blue}{e^{x} \cdot 1}}{e^{x}}}{-\left(e^{-x} - 1\right)} \]
    13. associate-*r/6.1%

      \[\leadsto \frac{\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}}{-\left(e^{-x} - 1\right)} \]
    14. rgt-mult-inverse32.7%

      \[\leadsto \frac{\color{blue}{1}}{-\left(e^{-x} - 1\right)} \]
    15. distribute-frac-neg232.7%

      \[\leadsto \color{blue}{-\frac{1}{e^{-x} - 1}} \]
    16. distribute-neg-frac32.7%

      \[\leadsto \color{blue}{\frac{-1}{e^{-x} - 1}} \]
    17. metadata-eval32.7%

      \[\leadsto \frac{\color{blue}{-1}}{e^{-x} - 1} \]
    18. expm1-define100.0%

      \[\leadsto \frac{-1}{\color{blue}{\mathsf{expm1}\left(-x\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{-1}{\mathsf{expm1}\left(-x\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 90.8%

    \[\leadsto \frac{-1}{\color{blue}{x \cdot \left(x \cdot \left(0.5 + -0.16666666666666666 \cdot x\right) - 1\right)}} \]
  6. Final simplification90.8%

    \[\leadsto \frac{-1}{x \cdot \left(-1 + x \cdot \left(0.5 + x \cdot -0.16666666666666666\right)\right)} \]
  7. Add Preprocessing

Alternative 4: 83.1% accurate, 22.8× speedup?

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

\\
\frac{-1}{x \cdot \left(-1 + x \cdot 0.5\right)}
\end{array}
Derivation
  1. Initial program 33.3%

    \[\frac{e^{x}}{e^{x} - 1} \]
  2. Step-by-step derivation
    1. sub-neg33.3%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} + \left(-1\right)}} \]
    2. +-commutative33.3%

      \[\leadsto \frac{e^{x}}{\color{blue}{\left(-1\right) + e^{x}}} \]
    3. rgt-mult-inverse6.8%

      \[\leadsto \frac{e^{x}}{\left(-\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}\right) + e^{x}} \]
    4. exp-neg6.8%

      \[\leadsto \frac{e^{x}}{\left(-e^{x} \cdot \color{blue}{e^{-x}}\right) + e^{x}} \]
    5. distribute-rgt-neg-out6.8%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(-e^{-x}\right)} + e^{x}} \]
    6. *-rgt-identity6.8%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(-e^{-x}\right) + \color{blue}{e^{x} \cdot 1}} \]
    7. distribute-lft-in6.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(\left(-e^{-x}\right) + 1\right)}} \]
    8. neg-sub06.7%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(\color{blue}{\left(0 - e^{-x}\right)} + 1\right)} \]
    9. associate-+l-6.7%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(0 - \left(e^{-x} - 1\right)\right)}} \]
    10. neg-sub06.1%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(-\left(e^{-x} - 1\right)\right)}} \]
    11. associate-/r*6.1%

      \[\leadsto \color{blue}{\frac{\frac{e^{x}}{e^{x}}}{-\left(e^{-x} - 1\right)}} \]
    12. *-rgt-identity6.1%

      \[\leadsto \frac{\frac{\color{blue}{e^{x} \cdot 1}}{e^{x}}}{-\left(e^{-x} - 1\right)} \]
    13. associate-*r/6.1%

      \[\leadsto \frac{\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}}{-\left(e^{-x} - 1\right)} \]
    14. rgt-mult-inverse32.7%

      \[\leadsto \frac{\color{blue}{1}}{-\left(e^{-x} - 1\right)} \]
    15. distribute-frac-neg232.7%

      \[\leadsto \color{blue}{-\frac{1}{e^{-x} - 1}} \]
    16. distribute-neg-frac32.7%

      \[\leadsto \color{blue}{\frac{-1}{e^{-x} - 1}} \]
    17. metadata-eval32.7%

      \[\leadsto \frac{\color{blue}{-1}}{e^{-x} - 1} \]
    18. expm1-define100.0%

      \[\leadsto \frac{-1}{\color{blue}{\mathsf{expm1}\left(-x\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{-1}{\mathsf{expm1}\left(-x\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 87.1%

    \[\leadsto \frac{-1}{\color{blue}{x \cdot \left(0.5 \cdot x - 1\right)}} \]
  6. Final simplification87.1%

    \[\leadsto \frac{-1}{x \cdot \left(-1 + x \cdot 0.5\right)} \]
  7. Add Preprocessing

Alternative 5: 66.6% accurate, 41.0× speedup?

\[\begin{array}{l} \\ 0.5 - \frac{-1}{x} \end{array} \]
(FPCore (x) :precision binary64 (- 0.5 (/ -1.0 x)))
double code(double x) {
	return 0.5 - (-1.0 / x);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 0.5d0 - ((-1.0d0) / x)
end function
public static double code(double x) {
	return 0.5 - (-1.0 / x);
}
def code(x):
	return 0.5 - (-1.0 / x)
function code(x)
	return Float64(0.5 - Float64(-1.0 / x))
end
function tmp = code(x)
	tmp = 0.5 - (-1.0 / x);
end
code[x_] := N[(0.5 - N[(-1.0 / x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0.5 - \frac{-1}{x}
\end{array}
Derivation
  1. Initial program 33.3%

    \[\frac{e^{x}}{e^{x} - 1} \]
  2. Step-by-step derivation
    1. sub-neg33.3%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} + \left(-1\right)}} \]
    2. +-commutative33.3%

      \[\leadsto \frac{e^{x}}{\color{blue}{\left(-1\right) + e^{x}}} \]
    3. rgt-mult-inverse6.8%

      \[\leadsto \frac{e^{x}}{\left(-\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}\right) + e^{x}} \]
    4. exp-neg6.8%

      \[\leadsto \frac{e^{x}}{\left(-e^{x} \cdot \color{blue}{e^{-x}}\right) + e^{x}} \]
    5. distribute-rgt-neg-out6.8%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(-e^{-x}\right)} + e^{x}} \]
    6. *-rgt-identity6.8%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(-e^{-x}\right) + \color{blue}{e^{x} \cdot 1}} \]
    7. distribute-lft-in6.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(\left(-e^{-x}\right) + 1\right)}} \]
    8. neg-sub06.7%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(\color{blue}{\left(0 - e^{-x}\right)} + 1\right)} \]
    9. associate-+l-6.7%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(0 - \left(e^{-x} - 1\right)\right)}} \]
    10. neg-sub06.1%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(-\left(e^{-x} - 1\right)\right)}} \]
    11. associate-/r*6.1%

      \[\leadsto \color{blue}{\frac{\frac{e^{x}}{e^{x}}}{-\left(e^{-x} - 1\right)}} \]
    12. *-rgt-identity6.1%

      \[\leadsto \frac{\frac{\color{blue}{e^{x} \cdot 1}}{e^{x}}}{-\left(e^{-x} - 1\right)} \]
    13. associate-*r/6.1%

      \[\leadsto \frac{\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}}{-\left(e^{-x} - 1\right)} \]
    14. rgt-mult-inverse32.7%

      \[\leadsto \frac{\color{blue}{1}}{-\left(e^{-x} - 1\right)} \]
    15. distribute-frac-neg232.7%

      \[\leadsto \color{blue}{-\frac{1}{e^{-x} - 1}} \]
    16. distribute-neg-frac32.7%

      \[\leadsto \color{blue}{\frac{-1}{e^{-x} - 1}} \]
    17. metadata-eval32.7%

      \[\leadsto \frac{\color{blue}{-1}}{e^{-x} - 1} \]
    18. expm1-define100.0%

      \[\leadsto \frac{-1}{\color{blue}{\mathsf{expm1}\left(-x\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{-1}{\mathsf{expm1}\left(-x\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 87.1%

    \[\leadsto \frac{-1}{\color{blue}{x \cdot \left(0.5 \cdot x - 1\right)}} \]
  6. Step-by-step derivation
    1. sub-neg87.1%

      \[\leadsto \frac{-1}{x \cdot \color{blue}{\left(0.5 \cdot x + \left(-1\right)\right)}} \]
    2. metadata-eval87.1%

      \[\leadsto \frac{-1}{x \cdot \left(0.5 \cdot x + \color{blue}{-1}\right)} \]
    3. distribute-rgt-in87.1%

      \[\leadsto \frac{-1}{\color{blue}{\left(0.5 \cdot x\right) \cdot x + -1 \cdot x}} \]
    4. *-commutative87.1%

      \[\leadsto \frac{-1}{\color{blue}{\left(x \cdot 0.5\right)} \cdot x + -1 \cdot x} \]
  7. Applied egg-rr87.1%

    \[\leadsto \frac{-1}{\color{blue}{\left(x \cdot 0.5\right) \cdot x + -1 \cdot x}} \]
  8. Taylor expanded in x around 0 71.6%

    \[\leadsto \color{blue}{\frac{1 + 0.5 \cdot x}{x}} \]
  9. Step-by-step derivation
    1. +-commutative71.6%

      \[\leadsto \frac{\color{blue}{0.5 \cdot x + 1}}{x} \]
    2. *-commutative71.6%

      \[\leadsto \frac{\color{blue}{x \cdot 0.5} + 1}{x} \]
    3. metadata-eval71.6%

      \[\leadsto \frac{x \cdot 0.5 + \color{blue}{\left(--1\right)}}{x} \]
    4. sub-neg71.6%

      \[\leadsto \frac{\color{blue}{x \cdot 0.5 - -1}}{x} \]
    5. div-sub71.6%

      \[\leadsto \color{blue}{\frac{x \cdot 0.5}{x} - \frac{-1}{x}} \]
    6. *-commutative71.6%

      \[\leadsto \frac{\color{blue}{0.5 \cdot x}}{x} - \frac{-1}{x} \]
    7. associate-*l/71.6%

      \[\leadsto \color{blue}{\frac{0.5}{x} \cdot x} - \frac{-1}{x} \]
    8. metadata-eval71.6%

      \[\leadsto \frac{\color{blue}{0.5 \cdot 1}}{x} \cdot x - \frac{-1}{x} \]
    9. associate-*r/71.6%

      \[\leadsto \color{blue}{\left(0.5 \cdot \frac{1}{x}\right)} \cdot x - \frac{-1}{x} \]
    10. associate-*l*71.6%

      \[\leadsto \color{blue}{0.5 \cdot \left(\frac{1}{x} \cdot x\right)} - \frac{-1}{x} \]
    11. lft-mult-inverse71.6%

      \[\leadsto 0.5 \cdot \color{blue}{1} - \frac{-1}{x} \]
    12. metadata-eval71.6%

      \[\leadsto \color{blue}{0.5} - \frac{-1}{x} \]
  10. Simplified71.6%

    \[\leadsto \color{blue}{0.5 - \frac{-1}{x}} \]
  11. Final simplification71.6%

    \[\leadsto 0.5 - \frac{-1}{x} \]
  12. Add Preprocessing

Alternative 6: 66.6% accurate, 68.3× speedup?

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

\\
\frac{1}{x}
\end{array}
Derivation
  1. Initial program 33.3%

    \[\frac{e^{x}}{e^{x} - 1} \]
  2. Step-by-step derivation
    1. sub-neg33.3%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} + \left(-1\right)}} \]
    2. +-commutative33.3%

      \[\leadsto \frac{e^{x}}{\color{blue}{\left(-1\right) + e^{x}}} \]
    3. rgt-mult-inverse6.8%

      \[\leadsto \frac{e^{x}}{\left(-\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}\right) + e^{x}} \]
    4. exp-neg6.8%

      \[\leadsto \frac{e^{x}}{\left(-e^{x} \cdot \color{blue}{e^{-x}}\right) + e^{x}} \]
    5. distribute-rgt-neg-out6.8%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(-e^{-x}\right)} + e^{x}} \]
    6. *-rgt-identity6.8%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(-e^{-x}\right) + \color{blue}{e^{x} \cdot 1}} \]
    7. distribute-lft-in6.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(\left(-e^{-x}\right) + 1\right)}} \]
    8. neg-sub06.7%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(\color{blue}{\left(0 - e^{-x}\right)} + 1\right)} \]
    9. associate-+l-6.7%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(0 - \left(e^{-x} - 1\right)\right)}} \]
    10. neg-sub06.1%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(-\left(e^{-x} - 1\right)\right)}} \]
    11. associate-/r*6.1%

      \[\leadsto \color{blue}{\frac{\frac{e^{x}}{e^{x}}}{-\left(e^{-x} - 1\right)}} \]
    12. *-rgt-identity6.1%

      \[\leadsto \frac{\frac{\color{blue}{e^{x} \cdot 1}}{e^{x}}}{-\left(e^{-x} - 1\right)} \]
    13. associate-*r/6.1%

      \[\leadsto \frac{\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}}{-\left(e^{-x} - 1\right)} \]
    14. rgt-mult-inverse32.7%

      \[\leadsto \frac{\color{blue}{1}}{-\left(e^{-x} - 1\right)} \]
    15. distribute-frac-neg232.7%

      \[\leadsto \color{blue}{-\frac{1}{e^{-x} - 1}} \]
    16. distribute-neg-frac32.7%

      \[\leadsto \color{blue}{\frac{-1}{e^{-x} - 1}} \]
    17. metadata-eval32.7%

      \[\leadsto \frac{\color{blue}{-1}}{e^{-x} - 1} \]
    18. expm1-define100.0%

      \[\leadsto \frac{-1}{\color{blue}{\mathsf{expm1}\left(-x\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{-1}{\mathsf{expm1}\left(-x\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 71.6%

    \[\leadsto \color{blue}{\frac{1}{x}} \]
  6. Final simplification71.6%

    \[\leadsto \frac{1}{x} \]
  7. Add Preprocessing

Alternative 7: 3.2% accurate, 205.0× speedup?

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

\\
-0.5
\end{array}
Derivation
  1. Initial program 33.3%

    \[\frac{e^{x}}{e^{x} - 1} \]
  2. Step-by-step derivation
    1. sub-neg33.3%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} + \left(-1\right)}} \]
    2. +-commutative33.3%

      \[\leadsto \frac{e^{x}}{\color{blue}{\left(-1\right) + e^{x}}} \]
    3. rgt-mult-inverse6.8%

      \[\leadsto \frac{e^{x}}{\left(-\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}\right) + e^{x}} \]
    4. exp-neg6.8%

      \[\leadsto \frac{e^{x}}{\left(-e^{x} \cdot \color{blue}{e^{-x}}\right) + e^{x}} \]
    5. distribute-rgt-neg-out6.8%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(-e^{-x}\right)} + e^{x}} \]
    6. *-rgt-identity6.8%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(-e^{-x}\right) + \color{blue}{e^{x} \cdot 1}} \]
    7. distribute-lft-in6.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(\left(-e^{-x}\right) + 1\right)}} \]
    8. neg-sub06.7%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(\color{blue}{\left(0 - e^{-x}\right)} + 1\right)} \]
    9. associate-+l-6.7%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(0 - \left(e^{-x} - 1\right)\right)}} \]
    10. neg-sub06.1%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(-\left(e^{-x} - 1\right)\right)}} \]
    11. associate-/r*6.1%

      \[\leadsto \color{blue}{\frac{\frac{e^{x}}{e^{x}}}{-\left(e^{-x} - 1\right)}} \]
    12. *-rgt-identity6.1%

      \[\leadsto \frac{\frac{\color{blue}{e^{x} \cdot 1}}{e^{x}}}{-\left(e^{-x} - 1\right)} \]
    13. associate-*r/6.1%

      \[\leadsto \frac{\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}}{-\left(e^{-x} - 1\right)} \]
    14. rgt-mult-inverse32.7%

      \[\leadsto \frac{\color{blue}{1}}{-\left(e^{-x} - 1\right)} \]
    15. distribute-frac-neg232.7%

      \[\leadsto \color{blue}{-\frac{1}{e^{-x} - 1}} \]
    16. distribute-neg-frac32.7%

      \[\leadsto \color{blue}{\frac{-1}{e^{-x} - 1}} \]
    17. metadata-eval32.7%

      \[\leadsto \frac{\color{blue}{-1}}{e^{-x} - 1} \]
    18. expm1-define100.0%

      \[\leadsto \frac{-1}{\color{blue}{\mathsf{expm1}\left(-x\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{-1}{\mathsf{expm1}\left(-x\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 71.6%

    \[\leadsto \color{blue}{\frac{1 + 0.5 \cdot x}{x}} \]
  6. Step-by-step derivation
    1. *-commutative71.6%

      \[\leadsto \frac{1 + \color{blue}{x \cdot 0.5}}{x} \]
  7. Simplified71.6%

    \[\leadsto \color{blue}{\frac{1 + x \cdot 0.5}{x}} \]
  8. Step-by-step derivation
    1. frac-2neg71.6%

      \[\leadsto \color{blue}{\frac{-\left(1 + x \cdot 0.5\right)}{-x}} \]
    2. mul-1-neg71.6%

      \[\leadsto \frac{-\left(1 + x \cdot 0.5\right)}{\color{blue}{-1 \cdot x}} \]
    3. div-inv71.6%

      \[\leadsto \color{blue}{\left(-\left(1 + x \cdot 0.5\right)\right) \cdot \frac{1}{-1 \cdot x}} \]
    4. +-commutative71.6%

      \[\leadsto \left(-\color{blue}{\left(x \cdot 0.5 + 1\right)}\right) \cdot \frac{1}{-1 \cdot x} \]
    5. fma-define71.6%

      \[\leadsto \left(-\color{blue}{\mathsf{fma}\left(x, 0.5, 1\right)}\right) \cdot \frac{1}{-1 \cdot x} \]
    6. add-sqr-sqrt28.5%

      \[\leadsto \left(-\mathsf{fma}\left(x, 0.5, 1\right)\right) \cdot \frac{1}{\color{blue}{\sqrt{-1 \cdot x} \cdot \sqrt{-1 \cdot x}}} \]
    7. sqrt-unprod30.4%

      \[\leadsto \left(-\mathsf{fma}\left(x, 0.5, 1\right)\right) \cdot \frac{1}{\color{blue}{\sqrt{\left(-1 \cdot x\right) \cdot \left(-1 \cdot x\right)}}} \]
    8. mul-1-neg30.4%

      \[\leadsto \left(-\mathsf{fma}\left(x, 0.5, 1\right)\right) \cdot \frac{1}{\sqrt{\color{blue}{\left(-x\right)} \cdot \left(-1 \cdot x\right)}} \]
    9. mul-1-neg30.4%

      \[\leadsto \left(-\mathsf{fma}\left(x, 0.5, 1\right)\right) \cdot \frac{1}{\sqrt{\left(-x\right) \cdot \color{blue}{\left(-x\right)}}} \]
    10. sqr-neg30.4%

      \[\leadsto \left(-\mathsf{fma}\left(x, 0.5, 1\right)\right) \cdot \frac{1}{\sqrt{\color{blue}{x \cdot x}}} \]
    11. sqrt-unprod0.3%

      \[\leadsto \left(-\mathsf{fma}\left(x, 0.5, 1\right)\right) \cdot \frac{1}{\color{blue}{\sqrt{x} \cdot \sqrt{x}}} \]
    12. add-sqr-sqrt1.5%

      \[\leadsto \left(-\mathsf{fma}\left(x, 0.5, 1\right)\right) \cdot \frac{1}{\color{blue}{x}} \]
  9. Applied egg-rr1.5%

    \[\leadsto \color{blue}{\left(-\mathsf{fma}\left(x, 0.5, 1\right)\right) \cdot \frac{1}{x}} \]
  10. Step-by-step derivation
    1. associate-*r/1.5%

      \[\leadsto \color{blue}{\frac{\left(-\mathsf{fma}\left(x, 0.5, 1\right)\right) \cdot 1}{x}} \]
    2. *-rgt-identity1.5%

      \[\leadsto \frac{\color{blue}{-\mathsf{fma}\left(x, 0.5, 1\right)}}{x} \]
    3. distribute-neg-frac1.5%

      \[\leadsto \color{blue}{-\frac{\mathsf{fma}\left(x, 0.5, 1\right)}{x}} \]
    4. *-lft-identity1.5%

      \[\leadsto -\frac{\color{blue}{1 \cdot \mathsf{fma}\left(x, 0.5, 1\right)}}{x} \]
    5. associate-*l/1.5%

      \[\leadsto -\color{blue}{\frac{1}{x} \cdot \mathsf{fma}\left(x, 0.5, 1\right)} \]
    6. fma-undefine1.5%

      \[\leadsto -\frac{1}{x} \cdot \color{blue}{\left(x \cdot 0.5 + 1\right)} \]
    7. distribute-lft-in1.5%

      \[\leadsto -\color{blue}{\left(\frac{1}{x} \cdot \left(x \cdot 0.5\right) + \frac{1}{x} \cdot 1\right)} \]
    8. *-commutative1.5%

      \[\leadsto -\left(\frac{1}{x} \cdot \color{blue}{\left(0.5 \cdot x\right)} + \frac{1}{x} \cdot 1\right) \]
    9. associate-*l*1.5%

      \[\leadsto -\left(\color{blue}{\left(\frac{1}{x} \cdot 0.5\right) \cdot x} + \frac{1}{x} \cdot 1\right) \]
    10. *-commutative1.5%

      \[\leadsto -\left(\color{blue}{\left(0.5 \cdot \frac{1}{x}\right)} \cdot x + \frac{1}{x} \cdot 1\right) \]
    11. associate-*l*1.5%

      \[\leadsto -\left(\color{blue}{0.5 \cdot \left(\frac{1}{x} \cdot x\right)} + \frac{1}{x} \cdot 1\right) \]
    12. lft-mult-inverse1.5%

      \[\leadsto -\left(0.5 \cdot \color{blue}{1} + \frac{1}{x} \cdot 1\right) \]
    13. metadata-eval1.5%

      \[\leadsto -\left(\color{blue}{0.5} + \frac{1}{x} \cdot 1\right) \]
    14. *-rgt-identity1.5%

      \[\leadsto -\left(0.5 + \color{blue}{\frac{1}{x}}\right) \]
    15. mul-1-neg1.5%

      \[\leadsto \color{blue}{-1 \cdot \left(0.5 + \frac{1}{x}\right)} \]
    16. distribute-lft-in1.5%

      \[\leadsto \color{blue}{-1 \cdot 0.5 + -1 \cdot \frac{1}{x}} \]
    17. metadata-eval1.5%

      \[\leadsto \color{blue}{-0.5} + -1 \cdot \frac{1}{x} \]
    18. neg-mul-11.5%

      \[\leadsto -0.5 + \color{blue}{\left(-\frac{1}{x}\right)} \]
    19. distribute-neg-frac1.5%

      \[\leadsto -0.5 + \color{blue}{\frac{-1}{x}} \]
    20. metadata-eval1.5%

      \[\leadsto -0.5 + \frac{\color{blue}{-1}}{x} \]
  11. Simplified1.5%

    \[\leadsto \color{blue}{-0.5 + \frac{-1}{x}} \]
  12. Taylor expanded in x around inf 3.0%

    \[\leadsto \color{blue}{-0.5} \]
  13. Final simplification3.0%

    \[\leadsto -0.5 \]
  14. Add Preprocessing

Alternative 8: 3.2% accurate, 205.0× speedup?

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

\\
0.5
\end{array}
Derivation
  1. Initial program 33.3%

    \[\frac{e^{x}}{e^{x} - 1} \]
  2. Step-by-step derivation
    1. sub-neg33.3%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} + \left(-1\right)}} \]
    2. +-commutative33.3%

      \[\leadsto \frac{e^{x}}{\color{blue}{\left(-1\right) + e^{x}}} \]
    3. rgt-mult-inverse6.8%

      \[\leadsto \frac{e^{x}}{\left(-\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}\right) + e^{x}} \]
    4. exp-neg6.8%

      \[\leadsto \frac{e^{x}}{\left(-e^{x} \cdot \color{blue}{e^{-x}}\right) + e^{x}} \]
    5. distribute-rgt-neg-out6.8%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(-e^{-x}\right)} + e^{x}} \]
    6. *-rgt-identity6.8%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(-e^{-x}\right) + \color{blue}{e^{x} \cdot 1}} \]
    7. distribute-lft-in6.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(\left(-e^{-x}\right) + 1\right)}} \]
    8. neg-sub06.7%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(\color{blue}{\left(0 - e^{-x}\right)} + 1\right)} \]
    9. associate-+l-6.7%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(0 - \left(e^{-x} - 1\right)\right)}} \]
    10. neg-sub06.1%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(-\left(e^{-x} - 1\right)\right)}} \]
    11. associate-/r*6.1%

      \[\leadsto \color{blue}{\frac{\frac{e^{x}}{e^{x}}}{-\left(e^{-x} - 1\right)}} \]
    12. *-rgt-identity6.1%

      \[\leadsto \frac{\frac{\color{blue}{e^{x} \cdot 1}}{e^{x}}}{-\left(e^{-x} - 1\right)} \]
    13. associate-*r/6.1%

      \[\leadsto \frac{\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}}{-\left(e^{-x} - 1\right)} \]
    14. rgt-mult-inverse32.7%

      \[\leadsto \frac{\color{blue}{1}}{-\left(e^{-x} - 1\right)} \]
    15. distribute-frac-neg232.7%

      \[\leadsto \color{blue}{-\frac{1}{e^{-x} - 1}} \]
    16. distribute-neg-frac32.7%

      \[\leadsto \color{blue}{\frac{-1}{e^{-x} - 1}} \]
    17. metadata-eval32.7%

      \[\leadsto \frac{\color{blue}{-1}}{e^{-x} - 1} \]
    18. expm1-define100.0%

      \[\leadsto \frac{-1}{\color{blue}{\mathsf{expm1}\left(-x\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{-1}{\mathsf{expm1}\left(-x\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 71.6%

    \[\leadsto \color{blue}{\frac{1 + 0.5 \cdot x}{x}} \]
  6. Step-by-step derivation
    1. *-commutative71.6%

      \[\leadsto \frac{1 + \color{blue}{x \cdot 0.5}}{x} \]
  7. Simplified71.6%

    \[\leadsto \color{blue}{\frac{1 + x \cdot 0.5}{x}} \]
  8. Taylor expanded in x around inf 3.7%

    \[\leadsto \color{blue}{0.5} \]
  9. Final simplification3.7%

    \[\leadsto 0.5 \]
  10. Add Preprocessing

Developer target: 100.0% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \frac{-1}{\mathsf{expm1}\left(-x\right)} \end{array} \]
(FPCore (x) :precision binary64 (/ (- 1.0) (expm1 (- x))))
double code(double x) {
	return -1.0 / expm1(-x);
}
public static double code(double x) {
	return -1.0 / Math.expm1(-x);
}
def code(x):
	return -1.0 / math.expm1(-x)
function code(x)
	return Float64(Float64(-1.0) / expm1(Float64(-x)))
end
code[x_] := N[((-1.0) / N[(Exp[(-x)] - 1), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-1}{\mathsf{expm1}\left(-x\right)}
\end{array}

Reproduce

?
herbie shell --seed 2024075 
(FPCore (x)
  :name "expq2 (section 3.11)"
  :precision binary64
  :pre (> 710.0 x)

  :alt
  (/ (- 1.0) (expm1 (- x)))

  (/ (exp x) (- (exp x) 1.0)))