Asymptote A

Percentage Accurate: 77.7% → 99.9%
Time: 5.8s
Alternatives: 7
Speedup: 1.2×

Specification

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

\\
\frac{1}{x + 1} - \frac{1}{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 7 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: 77.7% accurate, 1.0× speedup?

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

\\
\frac{1}{x + 1} - \frac{1}{x - 1}
\end{array}

Alternative 1: 99.9% accurate, 1.2× speedup?

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

\\
\frac{\frac{2}{x + -1}}{-1 - x}
\end{array}
Derivation
  1. Initial program 76.8%

    \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. sub-neg76.8%

      \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
    2. +-commutative76.8%

      \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
    3. distribute-neg-frac76.8%

      \[\leadsto \color{blue}{\frac{-1}{x - 1}} + \frac{1}{x + 1} \]
    4. metadata-eval76.8%

      \[\leadsto \frac{\color{blue}{-1}}{x - 1} + \frac{1}{x + 1} \]
    5. metadata-eval76.8%

      \[\leadsto \frac{\color{blue}{\frac{1}{-1}}}{x - 1} + \frac{1}{x + 1} \]
    6. metadata-eval76.8%

      \[\leadsto \frac{\frac{1}{\color{blue}{-1}}}{x - 1} + \frac{1}{x + 1} \]
    7. associate-/r*76.8%

      \[\leadsto \color{blue}{\frac{1}{\left(-1\right) \cdot \left(x - 1\right)}} + \frac{1}{x + 1} \]
    8. metadata-eval76.8%

      \[\leadsto \frac{1}{\color{blue}{-1} \cdot \left(x - 1\right)} + \frac{1}{x + 1} \]
    9. neg-mul-176.8%

      \[\leadsto \frac{1}{\color{blue}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
    10. sub0-neg76.8%

      \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
    11. associate-+l-76.8%

      \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
    12. neg-sub076.8%

      \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
    13. metadata-eval76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\color{blue}{\frac{-1}{-1}}}{x + 1} \]
    14. metadata-eval76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{\color{blue}{-1}}{-1}}{x + 1} \]
    15. metadata-eval76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{-1}{\color{blue}{-1}}}{x + 1} \]
    16. associate-/r*76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\frac{-1}{\left(-1\right) \cdot \left(x + 1\right)}} \]
    17. metadata-eval76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-1} \cdot \left(x + 1\right)} \]
    18. neg-mul-176.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-\left(x + 1\right)}} \]
    19. distribute-neg-in76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
    20. sub-neg76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) - 1}} \]
    21. distribute-neg-frac76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
    22. neg-mul-176.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{-1 \cdot \frac{1}{\left(-x\right) - 1}} \]
  3. Simplified76.8%

    \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. frac-sub78.0%

      \[\leadsto \color{blue}{\frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\left(1 - x\right) \cdot \left(-1 - x\right)}} \]
    2. *-rgt-identity78.0%

      \[\leadsto \frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\color{blue}{\left(\left(1 - x\right) \cdot 1\right)} \cdot \left(-1 - x\right)} \]
    3. metadata-eval78.0%

      \[\leadsto \frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\left(\left(1 - x\right) \cdot \color{blue}{\frac{1}{1}}\right) \cdot \left(-1 - x\right)} \]
    4. div-inv78.0%

      \[\leadsto \frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\color{blue}{\frac{1 - x}{1}} \cdot \left(-1 - x\right)} \]
    5. associate-/r*78.0%

      \[\leadsto \color{blue}{\frac{\frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\frac{1 - x}{1}}}{-1 - x}} \]
    6. *-un-lft-identity78.0%

      \[\leadsto \frac{\frac{\color{blue}{\left(-1 - x\right)} - \left(1 - x\right) \cdot 1}{\frac{1 - x}{1}}}{-1 - x} \]
    7. metadata-eval78.0%

      \[\leadsto \frac{\frac{\left(-1 - x\right) - \left(1 - x\right) \cdot \color{blue}{\frac{1}{1}}}{\frac{1 - x}{1}}}{-1 - x} \]
    8. div-inv78.0%

      \[\leadsto \frac{\frac{\left(-1 - x\right) - \color{blue}{\frac{1 - x}{1}}}{\frac{1 - x}{1}}}{-1 - x} \]
    9. associate--l-81.0%

      \[\leadsto \frac{\frac{\color{blue}{-1 - \left(x + \frac{1 - x}{1}\right)}}{\frac{1 - x}{1}}}{-1 - x} \]
    10. div-inv81.0%

      \[\leadsto \frac{\frac{-1 - \left(x + \color{blue}{\left(1 - x\right) \cdot \frac{1}{1}}\right)}{\frac{1 - x}{1}}}{-1 - x} \]
    11. metadata-eval81.0%

      \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right) \cdot \color{blue}{1}\right)}{\frac{1 - x}{1}}}{-1 - x} \]
    12. *-rgt-identity81.0%

      \[\leadsto \frac{\frac{-1 - \left(x + \color{blue}{\left(1 - x\right)}\right)}{\frac{1 - x}{1}}}{-1 - x} \]
    13. div-inv81.0%

      \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{\color{blue}{\left(1 - x\right) \cdot \frac{1}{1}}}}{-1 - x} \]
    14. metadata-eval81.0%

      \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{\left(1 - x\right) \cdot \color{blue}{1}}}{-1 - x} \]
    15. *-rgt-identity81.0%

      \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{\color{blue}{1 - x}}}{-1 - x} \]
  6. Applied egg-rr81.0%

    \[\leadsto \color{blue}{\frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{1 - x}}{-1 - x}} \]
  7. Step-by-step derivation
    1. div-sub81.0%

      \[\leadsto \frac{\color{blue}{\frac{-1}{1 - x} - \frac{x + \left(1 - x\right)}{1 - x}}}{-1 - x} \]
    2. sub-neg81.0%

      \[\leadsto \frac{\color{blue}{\frac{-1}{1 - x} + \left(-\frac{x + \left(1 - x\right)}{1 - x}\right)}}{-1 - x} \]
    3. +-commutative81.0%

      \[\leadsto \frac{\frac{-1}{1 - x} + \left(-\frac{\color{blue}{\left(1 - x\right) + x}}{1 - x}\right)}{-1 - x} \]
    4. associate-+l-99.9%

      \[\leadsto \frac{\frac{-1}{1 - x} + \left(-\frac{\color{blue}{1 - \left(x - x\right)}}{1 - x}\right)}{-1 - x} \]
  8. Applied egg-rr99.9%

    \[\leadsto \frac{\color{blue}{\frac{-1}{1 - x} + \left(-\frac{1 - \left(x - x\right)}{1 - x}\right)}}{-1 - x} \]
  9. Step-by-step derivation
    1. +-inverses99.9%

      \[\leadsto \frac{\frac{-1}{1 - x} + \left(-\frac{1 - \color{blue}{0}}{1 - x}\right)}{-1 - x} \]
    2. metadata-eval99.9%

      \[\leadsto \frac{\frac{-1}{1 - x} + \left(-\frac{\color{blue}{1}}{1 - x}\right)}{-1 - x} \]
    3. distribute-neg-frac99.9%

      \[\leadsto \frac{\frac{-1}{1 - x} + \color{blue}{\frac{-1}{1 - x}}}{-1 - x} \]
    4. metadata-eval99.9%

      \[\leadsto \frac{\frac{-1}{1 - x} + \frac{\color{blue}{-1}}{1 - x}}{-1 - x} \]
    5. count-299.9%

      \[\leadsto \frac{\color{blue}{2 \cdot \frac{-1}{1 - x}}}{-1 - x} \]
    6. sub-neg99.9%

      \[\leadsto \frac{2 \cdot \frac{-1}{\color{blue}{1 + \left(-x\right)}}}{-1 - x} \]
    7. metadata-eval99.9%

      \[\leadsto \frac{2 \cdot \frac{-1}{\color{blue}{\left(--1\right)} + \left(-x\right)}}{-1 - x} \]
    8. distribute-neg-in99.9%

      \[\leadsto \frac{2 \cdot \frac{-1}{\color{blue}{-\left(-1 + x\right)}}}{-1 - x} \]
    9. neg-mul-199.9%

      \[\leadsto \frac{2 \cdot \frac{-1}{\color{blue}{-1 \cdot \left(-1 + x\right)}}}{-1 - x} \]
    10. associate-/r*99.9%

      \[\leadsto \frac{2 \cdot \color{blue}{\frac{\frac{-1}{-1}}{-1 + x}}}{-1 - x} \]
    11. metadata-eval99.9%

      \[\leadsto \frac{2 \cdot \frac{\color{blue}{1}}{-1 + x}}{-1 - x} \]
    12. associate-*r/99.9%

      \[\leadsto \frac{\color{blue}{\frac{2 \cdot 1}{-1 + x}}}{-1 - x} \]
    13. metadata-eval99.9%

      \[\leadsto \frac{\frac{\color{blue}{2}}{-1 + x}}{-1 - x} \]
    14. +-commutative99.9%

      \[\leadsto \frac{\frac{2}{\color{blue}{x + -1}}}{-1 - x} \]
  10. Simplified99.9%

    \[\leadsto \frac{\color{blue}{\frac{2}{x + -1}}}{-1 - x} \]
  11. Final simplification99.9%

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

Alternative 2: 74.6% accurate, 0.9× speedup?

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

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1:\\
\;\;\;\;2 + 2 \cdot \left(x \cdot x\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{\frac{-2}{x}}{x}\\


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

    1. Initial program 82.5%

      \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. sub-neg82.5%

        \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
      2. +-commutative82.5%

        \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
      3. distribute-neg-frac82.5%

        \[\leadsto \color{blue}{\frac{-1}{x - 1}} + \frac{1}{x + 1} \]
      4. metadata-eval82.5%

        \[\leadsto \frac{\color{blue}{-1}}{x - 1} + \frac{1}{x + 1} \]
      5. metadata-eval82.5%

        \[\leadsto \frac{\color{blue}{\frac{1}{-1}}}{x - 1} + \frac{1}{x + 1} \]
      6. metadata-eval82.5%

        \[\leadsto \frac{\frac{1}{\color{blue}{-1}}}{x - 1} + \frac{1}{x + 1} \]
      7. associate-/r*82.5%

        \[\leadsto \color{blue}{\frac{1}{\left(-1\right) \cdot \left(x - 1\right)}} + \frac{1}{x + 1} \]
      8. metadata-eval82.5%

        \[\leadsto \frac{1}{\color{blue}{-1} \cdot \left(x - 1\right)} + \frac{1}{x + 1} \]
      9. neg-mul-182.5%

        \[\leadsto \frac{1}{\color{blue}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
      10. sub0-neg82.5%

        \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
      11. associate-+l-82.5%

        \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
      12. neg-sub082.5%

        \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
      13. metadata-eval82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\color{blue}{\frac{-1}{-1}}}{x + 1} \]
      14. metadata-eval82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{\color{blue}{-1}}{-1}}{x + 1} \]
      15. metadata-eval82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{-1}{\color{blue}{-1}}}{x + 1} \]
      16. associate-/r*82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\frac{-1}{\left(-1\right) \cdot \left(x + 1\right)}} \]
      17. metadata-eval82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-1} \cdot \left(x + 1\right)} \]
      18. neg-mul-182.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-\left(x + 1\right)}} \]
      19. distribute-neg-in82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
      20. sub-neg82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) - 1}} \]
      21. distribute-neg-frac82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
      22. neg-mul-182.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{-1 \cdot \frac{1}{\left(-x\right) - 1}} \]
    3. Simplified82.5%

      \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 67.3%

      \[\leadsto \color{blue}{2 + 2 \cdot {x}^{2}} \]
    6. Step-by-step derivation
      1. unpow232.9%

        \[\leadsto \frac{-2}{\color{blue}{x \cdot x}} \]
    7. Applied egg-rr67.3%

      \[\leadsto 2 + 2 \cdot \color{blue}{\left(x \cdot x\right)} \]

    if 1 < x

    1. Initial program 53.8%

      \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. sub-neg53.8%

        \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
      2. +-commutative53.8%

        \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
      3. distribute-neg-frac53.8%

        \[\leadsto \color{blue}{\frac{-1}{x - 1}} + \frac{1}{x + 1} \]
      4. metadata-eval53.8%

        \[\leadsto \frac{\color{blue}{-1}}{x - 1} + \frac{1}{x + 1} \]
      5. metadata-eval53.8%

        \[\leadsto \frac{\color{blue}{\frac{1}{-1}}}{x - 1} + \frac{1}{x + 1} \]
      6. metadata-eval53.8%

        \[\leadsto \frac{\frac{1}{\color{blue}{-1}}}{x - 1} + \frac{1}{x + 1} \]
      7. associate-/r*53.8%

        \[\leadsto \color{blue}{\frac{1}{\left(-1\right) \cdot \left(x - 1\right)}} + \frac{1}{x + 1} \]
      8. metadata-eval53.8%

        \[\leadsto \frac{1}{\color{blue}{-1} \cdot \left(x - 1\right)} + \frac{1}{x + 1} \]
      9. neg-mul-153.8%

        \[\leadsto \frac{1}{\color{blue}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
      10. sub0-neg53.8%

        \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
      11. associate-+l-53.8%

        \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
      12. neg-sub053.8%

        \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
      13. metadata-eval53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\color{blue}{\frac{-1}{-1}}}{x + 1} \]
      14. metadata-eval53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{\color{blue}{-1}}{-1}}{x + 1} \]
      15. metadata-eval53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{-1}{\color{blue}{-1}}}{x + 1} \]
      16. associate-/r*53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\frac{-1}{\left(-1\right) \cdot \left(x + 1\right)}} \]
      17. metadata-eval53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-1} \cdot \left(x + 1\right)} \]
      18. neg-mul-153.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-\left(x + 1\right)}} \]
      19. distribute-neg-in53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
      20. sub-neg53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) - 1}} \]
      21. distribute-neg-frac53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
      22. neg-mul-153.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{-1 \cdot \frac{1}{\left(-x\right) - 1}} \]
    3. Simplified53.8%

      \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 96.5%

      \[\leadsto \color{blue}{\frac{-2}{{x}^{2}}} \]
    6. Step-by-step derivation
      1. clear-num96.5%

        \[\leadsto \color{blue}{\frac{1}{\frac{{x}^{2}}{-2}}} \]
      2. associate-/r/96.5%

        \[\leadsto \color{blue}{\frac{1}{{x}^{2}} \cdot -2} \]
      3. pow-flip97.7%

        \[\leadsto \color{blue}{{x}^{\left(-2\right)}} \cdot -2 \]
      4. metadata-eval97.7%

        \[\leadsto {x}^{\color{blue}{-2}} \cdot -2 \]
    7. Applied egg-rr97.7%

      \[\leadsto \color{blue}{{x}^{-2} \cdot -2} \]
    8. Step-by-step derivation
      1. metadata-eval97.7%

        \[\leadsto {x}^{\color{blue}{\left(-2\right)}} \cdot -2 \]
      2. pow-flip96.5%

        \[\leadsto \color{blue}{\frac{1}{{x}^{2}}} \cdot -2 \]
      3. pow296.4%

        \[\leadsto \frac{1}{\color{blue}{x \cdot x}} \cdot -2 \]
      4. associate-/r/96.4%

        \[\leadsto \color{blue}{\frac{1}{\frac{x \cdot x}{-2}}} \]
      5. clear-num96.4%

        \[\leadsto \color{blue}{\frac{-2}{x \cdot x}} \]
      6. associate-/r*97.6%

        \[\leadsto \color{blue}{\frac{\frac{-2}{x}}{x}} \]
    9. Applied egg-rr97.6%

      \[\leadsto \color{blue}{\frac{\frac{-2}{x}}{x}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification73.4%

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

Alternative 3: 74.4% accurate, 1.1× speedup?

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

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1:\\
\;\;\;\;2\\

\mathbf{else}:\\
\;\;\;\;\frac{-2}{x \cdot x}\\


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

    1. Initial program 82.5%

      \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. sub-neg82.5%

        \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
      2. +-commutative82.5%

        \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
      3. distribute-neg-frac82.5%

        \[\leadsto \color{blue}{\frac{-1}{x - 1}} + \frac{1}{x + 1} \]
      4. metadata-eval82.5%

        \[\leadsto \frac{\color{blue}{-1}}{x - 1} + \frac{1}{x + 1} \]
      5. metadata-eval82.5%

        \[\leadsto \frac{\color{blue}{\frac{1}{-1}}}{x - 1} + \frac{1}{x + 1} \]
      6. metadata-eval82.5%

        \[\leadsto \frac{\frac{1}{\color{blue}{-1}}}{x - 1} + \frac{1}{x + 1} \]
      7. associate-/r*82.5%

        \[\leadsto \color{blue}{\frac{1}{\left(-1\right) \cdot \left(x - 1\right)}} + \frac{1}{x + 1} \]
      8. metadata-eval82.5%

        \[\leadsto \frac{1}{\color{blue}{-1} \cdot \left(x - 1\right)} + \frac{1}{x + 1} \]
      9. neg-mul-182.5%

        \[\leadsto \frac{1}{\color{blue}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
      10. sub0-neg82.5%

        \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
      11. associate-+l-82.5%

        \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
      12. neg-sub082.5%

        \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
      13. metadata-eval82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\color{blue}{\frac{-1}{-1}}}{x + 1} \]
      14. metadata-eval82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{\color{blue}{-1}}{-1}}{x + 1} \]
      15. metadata-eval82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{-1}{\color{blue}{-1}}}{x + 1} \]
      16. associate-/r*82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\frac{-1}{\left(-1\right) \cdot \left(x + 1\right)}} \]
      17. metadata-eval82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-1} \cdot \left(x + 1\right)} \]
      18. neg-mul-182.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-\left(x + 1\right)}} \]
      19. distribute-neg-in82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
      20. sub-neg82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) - 1}} \]
      21. distribute-neg-frac82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
      22. neg-mul-182.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{-1 \cdot \frac{1}{\left(-x\right) - 1}} \]
    3. Simplified82.5%

      \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 67.6%

      \[\leadsto \color{blue}{2} \]

    if 1 < x

    1. Initial program 53.8%

      \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. sub-neg53.8%

        \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
      2. +-commutative53.8%

        \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
      3. distribute-neg-frac53.8%

        \[\leadsto \color{blue}{\frac{-1}{x - 1}} + \frac{1}{x + 1} \]
      4. metadata-eval53.8%

        \[\leadsto \frac{\color{blue}{-1}}{x - 1} + \frac{1}{x + 1} \]
      5. metadata-eval53.8%

        \[\leadsto \frac{\color{blue}{\frac{1}{-1}}}{x - 1} + \frac{1}{x + 1} \]
      6. metadata-eval53.8%

        \[\leadsto \frac{\frac{1}{\color{blue}{-1}}}{x - 1} + \frac{1}{x + 1} \]
      7. associate-/r*53.8%

        \[\leadsto \color{blue}{\frac{1}{\left(-1\right) \cdot \left(x - 1\right)}} + \frac{1}{x + 1} \]
      8. metadata-eval53.8%

        \[\leadsto \frac{1}{\color{blue}{-1} \cdot \left(x - 1\right)} + \frac{1}{x + 1} \]
      9. neg-mul-153.8%

        \[\leadsto \frac{1}{\color{blue}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
      10. sub0-neg53.8%

        \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
      11. associate-+l-53.8%

        \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
      12. neg-sub053.8%

        \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
      13. metadata-eval53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\color{blue}{\frac{-1}{-1}}}{x + 1} \]
      14. metadata-eval53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{\color{blue}{-1}}{-1}}{x + 1} \]
      15. metadata-eval53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{-1}{\color{blue}{-1}}}{x + 1} \]
      16. associate-/r*53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\frac{-1}{\left(-1\right) \cdot \left(x + 1\right)}} \]
      17. metadata-eval53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-1} \cdot \left(x + 1\right)} \]
      18. neg-mul-153.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-\left(x + 1\right)}} \]
      19. distribute-neg-in53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
      20. sub-neg53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) - 1}} \]
      21. distribute-neg-frac53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
      22. neg-mul-153.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{-1 \cdot \frac{1}{\left(-x\right) - 1}} \]
    3. Simplified53.8%

      \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 96.5%

      \[\leadsto \color{blue}{\frac{-2}{{x}^{2}}} \]
    6. Step-by-step derivation
      1. unpow296.4%

        \[\leadsto \frac{-2}{\color{blue}{x \cdot x}} \]
    7. Applied egg-rr96.4%

      \[\leadsto \frac{-2}{\color{blue}{x \cdot x}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification73.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;2\\ \mathbf{else}:\\ \;\;\;\;\frac{-2}{x \cdot x}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 74.6% accurate, 1.1× speedup?

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

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1:\\
\;\;\;\;2\\

\mathbf{else}:\\
\;\;\;\;\frac{\frac{-2}{x}}{x}\\


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

    1. Initial program 82.5%

      \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. sub-neg82.5%

        \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
      2. +-commutative82.5%

        \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
      3. distribute-neg-frac82.5%

        \[\leadsto \color{blue}{\frac{-1}{x - 1}} + \frac{1}{x + 1} \]
      4. metadata-eval82.5%

        \[\leadsto \frac{\color{blue}{-1}}{x - 1} + \frac{1}{x + 1} \]
      5. metadata-eval82.5%

        \[\leadsto \frac{\color{blue}{\frac{1}{-1}}}{x - 1} + \frac{1}{x + 1} \]
      6. metadata-eval82.5%

        \[\leadsto \frac{\frac{1}{\color{blue}{-1}}}{x - 1} + \frac{1}{x + 1} \]
      7. associate-/r*82.5%

        \[\leadsto \color{blue}{\frac{1}{\left(-1\right) \cdot \left(x - 1\right)}} + \frac{1}{x + 1} \]
      8. metadata-eval82.5%

        \[\leadsto \frac{1}{\color{blue}{-1} \cdot \left(x - 1\right)} + \frac{1}{x + 1} \]
      9. neg-mul-182.5%

        \[\leadsto \frac{1}{\color{blue}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
      10. sub0-neg82.5%

        \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
      11. associate-+l-82.5%

        \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
      12. neg-sub082.5%

        \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
      13. metadata-eval82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\color{blue}{\frac{-1}{-1}}}{x + 1} \]
      14. metadata-eval82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{\color{blue}{-1}}{-1}}{x + 1} \]
      15. metadata-eval82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{-1}{\color{blue}{-1}}}{x + 1} \]
      16. associate-/r*82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\frac{-1}{\left(-1\right) \cdot \left(x + 1\right)}} \]
      17. metadata-eval82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-1} \cdot \left(x + 1\right)} \]
      18. neg-mul-182.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-\left(x + 1\right)}} \]
      19. distribute-neg-in82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
      20. sub-neg82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) - 1}} \]
      21. distribute-neg-frac82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
      22. neg-mul-182.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{-1 \cdot \frac{1}{\left(-x\right) - 1}} \]
    3. Simplified82.5%

      \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 67.6%

      \[\leadsto \color{blue}{2} \]

    if 1 < x

    1. Initial program 53.8%

      \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. sub-neg53.8%

        \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
      2. +-commutative53.8%

        \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
      3. distribute-neg-frac53.8%

        \[\leadsto \color{blue}{\frac{-1}{x - 1}} + \frac{1}{x + 1} \]
      4. metadata-eval53.8%

        \[\leadsto \frac{\color{blue}{-1}}{x - 1} + \frac{1}{x + 1} \]
      5. metadata-eval53.8%

        \[\leadsto \frac{\color{blue}{\frac{1}{-1}}}{x - 1} + \frac{1}{x + 1} \]
      6. metadata-eval53.8%

        \[\leadsto \frac{\frac{1}{\color{blue}{-1}}}{x - 1} + \frac{1}{x + 1} \]
      7. associate-/r*53.8%

        \[\leadsto \color{blue}{\frac{1}{\left(-1\right) \cdot \left(x - 1\right)}} + \frac{1}{x + 1} \]
      8. metadata-eval53.8%

        \[\leadsto \frac{1}{\color{blue}{-1} \cdot \left(x - 1\right)} + \frac{1}{x + 1} \]
      9. neg-mul-153.8%

        \[\leadsto \frac{1}{\color{blue}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
      10. sub0-neg53.8%

        \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
      11. associate-+l-53.8%

        \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
      12. neg-sub053.8%

        \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
      13. metadata-eval53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\color{blue}{\frac{-1}{-1}}}{x + 1} \]
      14. metadata-eval53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{\color{blue}{-1}}{-1}}{x + 1} \]
      15. metadata-eval53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{-1}{\color{blue}{-1}}}{x + 1} \]
      16. associate-/r*53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\frac{-1}{\left(-1\right) \cdot \left(x + 1\right)}} \]
      17. metadata-eval53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-1} \cdot \left(x + 1\right)} \]
      18. neg-mul-153.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-\left(x + 1\right)}} \]
      19. distribute-neg-in53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
      20. sub-neg53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) - 1}} \]
      21. distribute-neg-frac53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
      22. neg-mul-153.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{-1 \cdot \frac{1}{\left(-x\right) - 1}} \]
    3. Simplified53.8%

      \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 96.5%

      \[\leadsto \color{blue}{\frac{-2}{{x}^{2}}} \]
    6. Step-by-step derivation
      1. clear-num96.5%

        \[\leadsto \color{blue}{\frac{1}{\frac{{x}^{2}}{-2}}} \]
      2. associate-/r/96.5%

        \[\leadsto \color{blue}{\frac{1}{{x}^{2}} \cdot -2} \]
      3. pow-flip97.7%

        \[\leadsto \color{blue}{{x}^{\left(-2\right)}} \cdot -2 \]
      4. metadata-eval97.7%

        \[\leadsto {x}^{\color{blue}{-2}} \cdot -2 \]
    7. Applied egg-rr97.7%

      \[\leadsto \color{blue}{{x}^{-2} \cdot -2} \]
    8. Step-by-step derivation
      1. metadata-eval97.7%

        \[\leadsto {x}^{\color{blue}{\left(-2\right)}} \cdot -2 \]
      2. pow-flip96.5%

        \[\leadsto \color{blue}{\frac{1}{{x}^{2}}} \cdot -2 \]
      3. pow296.4%

        \[\leadsto \frac{1}{\color{blue}{x \cdot x}} \cdot -2 \]
      4. associate-/r/96.4%

        \[\leadsto \color{blue}{\frac{1}{\frac{x \cdot x}{-2}}} \]
      5. clear-num96.4%

        \[\leadsto \color{blue}{\frac{-2}{x \cdot x}} \]
      6. associate-/r*97.6%

        \[\leadsto \color{blue}{\frac{\frac{-2}{x}}{x}} \]
    9. Applied egg-rr97.6%

      \[\leadsto \color{blue}{\frac{\frac{-2}{x}}{x}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification73.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;2\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{-2}{x}}{x}\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 99.4% accurate, 1.2× speedup?

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

\\
\frac{2}{\left(x + -1\right) \cdot \left(-1 - x\right)}
\end{array}
Derivation
  1. Initial program 76.8%

    \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. sub-neg76.8%

      \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
    2. +-commutative76.8%

      \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
    3. distribute-neg-frac76.8%

      \[\leadsto \color{blue}{\frac{-1}{x - 1}} + \frac{1}{x + 1} \]
    4. metadata-eval76.8%

      \[\leadsto \frac{\color{blue}{-1}}{x - 1} + \frac{1}{x + 1} \]
    5. metadata-eval76.8%

      \[\leadsto \frac{\color{blue}{\frac{1}{-1}}}{x - 1} + \frac{1}{x + 1} \]
    6. metadata-eval76.8%

      \[\leadsto \frac{\frac{1}{\color{blue}{-1}}}{x - 1} + \frac{1}{x + 1} \]
    7. associate-/r*76.8%

      \[\leadsto \color{blue}{\frac{1}{\left(-1\right) \cdot \left(x - 1\right)}} + \frac{1}{x + 1} \]
    8. metadata-eval76.8%

      \[\leadsto \frac{1}{\color{blue}{-1} \cdot \left(x - 1\right)} + \frac{1}{x + 1} \]
    9. neg-mul-176.8%

      \[\leadsto \frac{1}{\color{blue}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
    10. sub0-neg76.8%

      \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
    11. associate-+l-76.8%

      \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
    12. neg-sub076.8%

      \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
    13. metadata-eval76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\color{blue}{\frac{-1}{-1}}}{x + 1} \]
    14. metadata-eval76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{\color{blue}{-1}}{-1}}{x + 1} \]
    15. metadata-eval76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{-1}{\color{blue}{-1}}}{x + 1} \]
    16. associate-/r*76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\frac{-1}{\left(-1\right) \cdot \left(x + 1\right)}} \]
    17. metadata-eval76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-1} \cdot \left(x + 1\right)} \]
    18. neg-mul-176.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-\left(x + 1\right)}} \]
    19. distribute-neg-in76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
    20. sub-neg76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) - 1}} \]
    21. distribute-neg-frac76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
    22. neg-mul-176.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{-1 \cdot \frac{1}{\left(-x\right) - 1}} \]
  3. Simplified76.8%

    \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. sub-neg76.8%

      \[\leadsto \color{blue}{\frac{1}{1 - x} + \left(-\frac{1}{-1 - x}\right)} \]
    2. distribute-neg-frac76.8%

      \[\leadsto \frac{1}{1 - x} + \color{blue}{\frac{-1}{-1 - x}} \]
    3. metadata-eval76.8%

      \[\leadsto \frac{1}{1 - x} + \frac{\color{blue}{-1}}{-1 - x} \]
  6. Applied egg-rr76.8%

    \[\leadsto \color{blue}{\frac{1}{1 - x} + \frac{-1}{-1 - x}} \]
  7. Step-by-step derivation
    1. *-rgt-identity76.8%

      \[\leadsto \frac{1}{1 - x} + \color{blue}{\frac{-1}{-1 - x} \cdot 1} \]
    2. cancel-sign-sub76.8%

      \[\leadsto \color{blue}{\frac{1}{1 - x} - \left(-\frac{-1}{-1 - x}\right) \cdot 1} \]
    3. distribute-neg-frac76.8%

      \[\leadsto \frac{1}{1 - x} - \color{blue}{\frac{--1}{-1 - x}} \cdot 1 \]
    4. metadata-eval76.8%

      \[\leadsto \frac{1}{1 - x} - \frac{\color{blue}{1}}{-1 - x} \cdot 1 \]
    5. *-inverses76.8%

      \[\leadsto \frac{\color{blue}{\frac{-\left(-1 - x\right)}{-\left(-1 - x\right)}}}{1 - x} - \frac{1}{-1 - x} \cdot 1 \]
    6. associate-/r*58.2%

      \[\leadsto \color{blue}{\frac{-\left(-1 - x\right)}{\left(-\left(-1 - x\right)\right) \cdot \left(1 - x\right)}} - \frac{1}{-1 - x} \cdot 1 \]
    7. distribute-lft-neg-in58.2%

      \[\leadsto \frac{-\left(-1 - x\right)}{\color{blue}{-\left(-1 - x\right) \cdot \left(1 - x\right)}} - \frac{1}{-1 - x} \cdot 1 \]
    8. distribute-rgt-neg-in58.2%

      \[\leadsto \frac{-\left(-1 - x\right)}{\color{blue}{\left(-1 - x\right) \cdot \left(-\left(1 - x\right)\right)}} - \frac{1}{-1 - x} \cdot 1 \]
    9. *-commutative58.2%

      \[\leadsto \frac{-\left(-1 - x\right)}{\color{blue}{\left(-\left(1 - x\right)\right) \cdot \left(-1 - x\right)}} - \frac{1}{-1 - x} \cdot 1 \]
    10. *-commutative58.2%

      \[\leadsto \frac{-\left(-1 - x\right)}{\left(-\left(1 - x\right)\right) \cdot \left(-1 - x\right)} - \color{blue}{1 \cdot \frac{1}{-1 - x}} \]
    11. *-inverses58.2%

      \[\leadsto \frac{-\left(-1 - x\right)}{\left(-\left(1 - x\right)\right) \cdot \left(-1 - x\right)} - \color{blue}{\frac{-\left(1 - x\right)}{-\left(1 - x\right)}} \cdot \frac{1}{-1 - x} \]
    12. times-frac76.8%

      \[\leadsto \frac{-\left(-1 - x\right)}{\left(-\left(1 - x\right)\right) \cdot \left(-1 - x\right)} - \color{blue}{\frac{\left(-\left(1 - x\right)\right) \cdot 1}{\left(-\left(1 - x\right)\right) \cdot \left(-1 - x\right)}} \]
    13. div-sub78.0%

      \[\leadsto \color{blue}{\frac{\left(-\left(-1 - x\right)\right) - \left(-\left(1 - x\right)\right) \cdot 1}{\left(-\left(1 - x\right)\right) \cdot \left(-1 - x\right)}} \]
  8. Simplified99.3%

    \[\leadsto \color{blue}{\frac{2}{\left(-1 - x\right) \cdot \left(x + -1\right)}} \]
  9. Final simplification99.3%

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

Alternative 6: 51.8% accurate, 1.4× speedup?

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

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1:\\
\;\;\;\;2\\

\mathbf{else}:\\
\;\;\;\;\frac{-2}{x}\\


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

    1. Initial program 82.5%

      \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. sub-neg82.5%

        \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
      2. +-commutative82.5%

        \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
      3. distribute-neg-frac82.5%

        \[\leadsto \color{blue}{\frac{-1}{x - 1}} + \frac{1}{x + 1} \]
      4. metadata-eval82.5%

        \[\leadsto \frac{\color{blue}{-1}}{x - 1} + \frac{1}{x + 1} \]
      5. metadata-eval82.5%

        \[\leadsto \frac{\color{blue}{\frac{1}{-1}}}{x - 1} + \frac{1}{x + 1} \]
      6. metadata-eval82.5%

        \[\leadsto \frac{\frac{1}{\color{blue}{-1}}}{x - 1} + \frac{1}{x + 1} \]
      7. associate-/r*82.5%

        \[\leadsto \color{blue}{\frac{1}{\left(-1\right) \cdot \left(x - 1\right)}} + \frac{1}{x + 1} \]
      8. metadata-eval82.5%

        \[\leadsto \frac{1}{\color{blue}{-1} \cdot \left(x - 1\right)} + \frac{1}{x + 1} \]
      9. neg-mul-182.5%

        \[\leadsto \frac{1}{\color{blue}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
      10. sub0-neg82.5%

        \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
      11. associate-+l-82.5%

        \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
      12. neg-sub082.5%

        \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
      13. metadata-eval82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\color{blue}{\frac{-1}{-1}}}{x + 1} \]
      14. metadata-eval82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{\color{blue}{-1}}{-1}}{x + 1} \]
      15. metadata-eval82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{-1}{\color{blue}{-1}}}{x + 1} \]
      16. associate-/r*82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\frac{-1}{\left(-1\right) \cdot \left(x + 1\right)}} \]
      17. metadata-eval82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-1} \cdot \left(x + 1\right)} \]
      18. neg-mul-182.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-\left(x + 1\right)}} \]
      19. distribute-neg-in82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
      20. sub-neg82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) - 1}} \]
      21. distribute-neg-frac82.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
      22. neg-mul-182.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{-1 \cdot \frac{1}{\left(-x\right) - 1}} \]
    3. Simplified82.5%

      \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 67.6%

      \[\leadsto \color{blue}{2} \]

    if 1 < x

    1. Initial program 53.8%

      \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. sub-neg53.8%

        \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
      2. +-commutative53.8%

        \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
      3. distribute-neg-frac53.8%

        \[\leadsto \color{blue}{\frac{-1}{x - 1}} + \frac{1}{x + 1} \]
      4. metadata-eval53.8%

        \[\leadsto \frac{\color{blue}{-1}}{x - 1} + \frac{1}{x + 1} \]
      5. metadata-eval53.8%

        \[\leadsto \frac{\color{blue}{\frac{1}{-1}}}{x - 1} + \frac{1}{x + 1} \]
      6. metadata-eval53.8%

        \[\leadsto \frac{\frac{1}{\color{blue}{-1}}}{x - 1} + \frac{1}{x + 1} \]
      7. associate-/r*53.8%

        \[\leadsto \color{blue}{\frac{1}{\left(-1\right) \cdot \left(x - 1\right)}} + \frac{1}{x + 1} \]
      8. metadata-eval53.8%

        \[\leadsto \frac{1}{\color{blue}{-1} \cdot \left(x - 1\right)} + \frac{1}{x + 1} \]
      9. neg-mul-153.8%

        \[\leadsto \frac{1}{\color{blue}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
      10. sub0-neg53.8%

        \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
      11. associate-+l-53.8%

        \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
      12. neg-sub053.8%

        \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
      13. metadata-eval53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\color{blue}{\frac{-1}{-1}}}{x + 1} \]
      14. metadata-eval53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{\color{blue}{-1}}{-1}}{x + 1} \]
      15. metadata-eval53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{-1}{\color{blue}{-1}}}{x + 1} \]
      16. associate-/r*53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\frac{-1}{\left(-1\right) \cdot \left(x + 1\right)}} \]
      17. metadata-eval53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-1} \cdot \left(x + 1\right)} \]
      18. neg-mul-153.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-\left(x + 1\right)}} \]
      19. distribute-neg-in53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
      20. sub-neg53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) - 1}} \]
      21. distribute-neg-frac53.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
      22. neg-mul-153.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{-1 \cdot \frac{1}{\left(-x\right) - 1}} \]
    3. Simplified53.8%

      \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. frac-sub56.5%

        \[\leadsto \color{blue}{\frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\left(1 - x\right) \cdot \left(-1 - x\right)}} \]
      2. *-rgt-identity56.5%

        \[\leadsto \frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\color{blue}{\left(\left(1 - x\right) \cdot 1\right)} \cdot \left(-1 - x\right)} \]
      3. metadata-eval56.5%

        \[\leadsto \frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\left(\left(1 - x\right) \cdot \color{blue}{\frac{1}{1}}\right) \cdot \left(-1 - x\right)} \]
      4. div-inv56.5%

        \[\leadsto \frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\color{blue}{\frac{1 - x}{1}} \cdot \left(-1 - x\right)} \]
      5. associate-/r*56.5%

        \[\leadsto \color{blue}{\frac{\frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\frac{1 - x}{1}}}{-1 - x}} \]
      6. *-un-lft-identity56.5%

        \[\leadsto \frac{\frac{\color{blue}{\left(-1 - x\right)} - \left(1 - x\right) \cdot 1}{\frac{1 - x}{1}}}{-1 - x} \]
      7. metadata-eval56.5%

        \[\leadsto \frac{\frac{\left(-1 - x\right) - \left(1 - x\right) \cdot \color{blue}{\frac{1}{1}}}{\frac{1 - x}{1}}}{-1 - x} \]
      8. div-inv56.5%

        \[\leadsto \frac{\frac{\left(-1 - x\right) - \color{blue}{\frac{1 - x}{1}}}{\frac{1 - x}{1}}}{-1 - x} \]
      9. associate--l-62.3%

        \[\leadsto \frac{\frac{\color{blue}{-1 - \left(x + \frac{1 - x}{1}\right)}}{\frac{1 - x}{1}}}{-1 - x} \]
      10. div-inv62.3%

        \[\leadsto \frac{\frac{-1 - \left(x + \color{blue}{\left(1 - x\right) \cdot \frac{1}{1}}\right)}{\frac{1 - x}{1}}}{-1 - x} \]
      11. metadata-eval62.3%

        \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right) \cdot \color{blue}{1}\right)}{\frac{1 - x}{1}}}{-1 - x} \]
      12. *-rgt-identity62.3%

        \[\leadsto \frac{\frac{-1 - \left(x + \color{blue}{\left(1 - x\right)}\right)}{\frac{1 - x}{1}}}{-1 - x} \]
      13. div-inv62.3%

        \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{\color{blue}{\left(1 - x\right) \cdot \frac{1}{1}}}}{-1 - x} \]
      14. metadata-eval62.3%

        \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{\left(1 - x\right) \cdot \color{blue}{1}}}{-1 - x} \]
      15. *-rgt-identity62.3%

        \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{\color{blue}{1 - x}}}{-1 - x} \]
    6. Applied egg-rr62.3%

      \[\leadsto \color{blue}{\frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{1 - x}}{-1 - x}} \]
    7. Taylor expanded in x around inf 96.5%

      \[\leadsto \frac{\color{blue}{\frac{2}{x}}}{-1 - x} \]
    8. Taylor expanded in x around 0 7.7%

      \[\leadsto \color{blue}{\frac{-2}{x}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification55.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;2\\ \mathbf{else}:\\ \;\;\;\;\frac{-2}{x}\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 50.8% accurate, 11.0× speedup?

\[\begin{array}{l} \\ 2 \end{array} \]
(FPCore (x) :precision binary64 2.0)
double code(double x) {
	return 2.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 2.0d0
end function
public static double code(double x) {
	return 2.0;
}
def code(x):
	return 2.0
function code(x)
	return 2.0
end
function tmp = code(x)
	tmp = 2.0;
end
code[x_] := 2.0
\begin{array}{l}

\\
2
\end{array}
Derivation
  1. Initial program 76.8%

    \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. sub-neg76.8%

      \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
    2. +-commutative76.8%

      \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
    3. distribute-neg-frac76.8%

      \[\leadsto \color{blue}{\frac{-1}{x - 1}} + \frac{1}{x + 1} \]
    4. metadata-eval76.8%

      \[\leadsto \frac{\color{blue}{-1}}{x - 1} + \frac{1}{x + 1} \]
    5. metadata-eval76.8%

      \[\leadsto \frac{\color{blue}{\frac{1}{-1}}}{x - 1} + \frac{1}{x + 1} \]
    6. metadata-eval76.8%

      \[\leadsto \frac{\frac{1}{\color{blue}{-1}}}{x - 1} + \frac{1}{x + 1} \]
    7. associate-/r*76.8%

      \[\leadsto \color{blue}{\frac{1}{\left(-1\right) \cdot \left(x - 1\right)}} + \frac{1}{x + 1} \]
    8. metadata-eval76.8%

      \[\leadsto \frac{1}{\color{blue}{-1} \cdot \left(x - 1\right)} + \frac{1}{x + 1} \]
    9. neg-mul-176.8%

      \[\leadsto \frac{1}{\color{blue}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
    10. sub0-neg76.8%

      \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
    11. associate-+l-76.8%

      \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
    12. neg-sub076.8%

      \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
    13. metadata-eval76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\color{blue}{\frac{-1}{-1}}}{x + 1} \]
    14. metadata-eval76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{\color{blue}{-1}}{-1}}{x + 1} \]
    15. metadata-eval76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{\frac{-1}{\color{blue}{-1}}}{x + 1} \]
    16. associate-/r*76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\frac{-1}{\left(-1\right) \cdot \left(x + 1\right)}} \]
    17. metadata-eval76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-1} \cdot \left(x + 1\right)} \]
    18. neg-mul-176.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{-\left(x + 1\right)}} \]
    19. distribute-neg-in76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
    20. sub-neg76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{-1}{\color{blue}{\left(-x\right) - 1}} \]
    21. distribute-neg-frac76.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
    22. neg-mul-176.8%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{-1 \cdot \frac{1}{\left(-x\right) - 1}} \]
  3. Simplified76.8%

    \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 54.7%

    \[\leadsto \color{blue}{2} \]
  6. Final simplification54.7%

    \[\leadsto 2 \]
  7. Add Preprocessing

Reproduce

?
herbie shell --seed 2024020 
(FPCore (x)
  :name "Asymptote A"
  :precision binary64
  (- (/ 1.0 (+ x 1.0)) (/ 1.0 (- x 1.0))))