Asymptote A

Percentage Accurate: 77.0% → 99.9%
Time: 8.5s
Alternatives: 6
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 6 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: 77.0% 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 78.2%

    \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. sub-neg78.2%

      \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
    2. +-commutative78.2%

      \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
    3. distribute-neg-frac278.2%

      \[\leadsto \color{blue}{\frac{1}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
    4. neg-sub078.2%

      \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
    5. associate-+l-78.2%

      \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
    6. neg-sub078.2%

      \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
    7. remove-double-neg78.2%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{\color{blue}{-\left(-\left(x + 1\right)\right)}} \]
    8. distribute-neg-in78.2%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}} \]
    9. sub-neg78.2%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) - 1\right)}} \]
    10. distribute-neg-frac278.2%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
    11. sub-neg78.2%

      \[\leadsto \color{blue}{\frac{1}{\left(-x\right) + 1} - \frac{1}{\left(-x\right) - 1}} \]
    12. +-commutative78.2%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(-x\right)}} - \frac{1}{\left(-x\right) - 1} \]
    13. unsub-neg78.2%

      \[\leadsto \frac{1}{\color{blue}{1 - x}} - \frac{1}{\left(-x\right) - 1} \]
    14. sub-neg78.2%

      \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
    15. +-commutative78.2%

      \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) + \left(-x\right)}} \]
    16. unsub-neg78.2%

      \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) - x}} \]
    17. metadata-eval78.2%

      \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{-1} - x} \]
  3. Simplified78.2%

    \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. frac-sub79.3%

      \[\leadsto \color{blue}{\frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\left(1 - x\right) \cdot \left(-1 - x\right)}} \]
    2. *-rgt-identity79.3%

      \[\leadsto \frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\color{blue}{\left(\left(1 - x\right) \cdot 1\right)} \cdot \left(-1 - x\right)} \]
    3. metadata-eval79.3%

      \[\leadsto \frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\left(\left(1 - x\right) \cdot \color{blue}{\frac{1}{1}}\right) \cdot \left(-1 - x\right)} \]
    4. div-inv79.3%

      \[\leadsto \frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\color{blue}{\frac{1 - x}{1}} \cdot \left(-1 - x\right)} \]
    5. associate-/r*79.3%

      \[\leadsto \color{blue}{\frac{\frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\frac{1 - x}{1}}}{-1 - x}} \]
    6. *-un-lft-identity79.3%

      \[\leadsto \frac{\frac{\color{blue}{\left(-1 - x\right)} - \left(1 - x\right) \cdot 1}{\frac{1 - x}{1}}}{-1 - x} \]
    7. metadata-eval79.3%

      \[\leadsto \frac{\frac{\left(-1 - x\right) - \left(1 - x\right) \cdot \color{blue}{\frac{1}{1}}}{\frac{1 - x}{1}}}{-1 - x} \]
    8. div-inv79.3%

      \[\leadsto \frac{\frac{\left(-1 - x\right) - \color{blue}{\frac{1 - x}{1}}}{\frac{1 - x}{1}}}{-1 - x} \]
    9. associate--l-82.0%

      \[\leadsto \frac{\frac{\color{blue}{-1 - \left(x + \frac{1 - x}{1}\right)}}{\frac{1 - x}{1}}}{-1 - x} \]
    10. div-inv82.0%

      \[\leadsto \frac{\frac{-1 - \left(x + \color{blue}{\left(1 - x\right) \cdot \frac{1}{1}}\right)}{\frac{1 - x}{1}}}{-1 - x} \]
    11. metadata-eval82.0%

      \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right) \cdot \color{blue}{1}\right)}{\frac{1 - x}{1}}}{-1 - x} \]
    12. *-rgt-identity82.0%

      \[\leadsto \frac{\frac{-1 - \left(x + \color{blue}{\left(1 - x\right)}\right)}{\frac{1 - x}{1}}}{-1 - x} \]
    13. div-inv82.0%

      \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{\color{blue}{\left(1 - x\right) \cdot \frac{1}{1}}}}{-1 - x} \]
    14. metadata-eval82.0%

      \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{\left(1 - x\right) \cdot \color{blue}{1}}}{-1 - x} \]
    15. *-rgt-identity82.0%

      \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{\color{blue}{1 - x}}}{-1 - x} \]
  6. Applied egg-rr82.0%

    \[\leadsto \color{blue}{\frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{1 - x}}{-1 - x}} \]
  7. Step-by-step derivation
    1. div-sub82.0%

      \[\leadsto \frac{\color{blue}{\frac{-1}{1 - x} - \frac{x + \left(1 - x\right)}{1 - x}}}{-1 - x} \]
    2. sub-neg82.0%

      \[\leadsto \frac{\color{blue}{\frac{-1}{1 - x} + \left(-\frac{x + \left(1 - x\right)}{1 - x}\right)}}{-1 - x} \]
    3. frac-2neg82.0%

      \[\leadsto \frac{\color{blue}{\frac{--1}{-\left(1 - x\right)}} + \left(-\frac{x + \left(1 - x\right)}{1 - x}\right)}{-1 - x} \]
    4. metadata-eval82.0%

      \[\leadsto \frac{\frac{\color{blue}{1}}{-\left(1 - x\right)} + \left(-\frac{x + \left(1 - x\right)}{1 - x}\right)}{-1 - x} \]
    5. flip--81.9%

      \[\leadsto \frac{\frac{1}{-\color{blue}{\frac{1 \cdot 1 - x \cdot x}{1 + x}}} + \left(-\frac{x + \left(1 - x\right)}{1 - x}\right)}{-1 - x} \]
    6. metadata-eval81.9%

      \[\leadsto \frac{\frac{1}{-\frac{\color{blue}{1} - x \cdot x}{1 + x}} + \left(-\frac{x + \left(1 - x\right)}{1 - x}\right)}{-1 - x} \]
    7. unpow281.9%

      \[\leadsto \frac{\frac{1}{-\frac{1 - \color{blue}{{x}^{2}}}{1 + x}} + \left(-\frac{x + \left(1 - x\right)}{1 - x}\right)}{-1 - x} \]
    8. +-commutative81.9%

      \[\leadsto \frac{\frac{1}{-\frac{1 - {x}^{2}}{\color{blue}{x + 1}}} + \left(-\frac{x + \left(1 - x\right)}{1 - x}\right)}{-1 - x} \]
    9. distribute-neg-frac281.9%

      \[\leadsto \frac{\frac{1}{\color{blue}{\frac{1 - {x}^{2}}{-\left(x + 1\right)}}} + \left(-\frac{x + \left(1 - x\right)}{1 - x}\right)}{-1 - x} \]
    10. metadata-eval81.9%

      \[\leadsto \frac{\frac{1}{\frac{\color{blue}{-1 \cdot -1} - {x}^{2}}{-\left(x + 1\right)}} + \left(-\frac{x + \left(1 - x\right)}{1 - x}\right)}{-1 - x} \]
    11. unpow281.9%

      \[\leadsto \frac{\frac{1}{\frac{-1 \cdot -1 - \color{blue}{x \cdot x}}{-\left(x + 1\right)}} + \left(-\frac{x + \left(1 - x\right)}{1 - x}\right)}{-1 - x} \]
    12. +-commutative81.9%

      \[\leadsto \frac{\frac{1}{\frac{-1 \cdot -1 - x \cdot x}{-\color{blue}{\left(1 + x\right)}}} + \left(-\frac{x + \left(1 - x\right)}{1 - x}\right)}{-1 - x} \]
    13. distribute-neg-in81.9%

      \[\leadsto \frac{\frac{1}{\frac{-1 \cdot -1 - x \cdot x}{\color{blue}{\left(-1\right) + \left(-x\right)}}} + \left(-\frac{x + \left(1 - x\right)}{1 - x}\right)}{-1 - x} \]
    14. metadata-eval81.9%

      \[\leadsto \frac{\frac{1}{\frac{-1 \cdot -1 - x \cdot x}{\color{blue}{-1} + \left(-x\right)}} + \left(-\frac{x + \left(1 - x\right)}{1 - x}\right)}{-1 - x} \]
    15. sub-neg81.9%

      \[\leadsto \frac{\frac{1}{\frac{-1 \cdot -1 - x \cdot x}{\color{blue}{-1 - x}}} + \left(-\frac{x + \left(1 - x\right)}{1 - x}\right)}{-1 - x} \]
    16. flip-+82.0%

      \[\leadsto \frac{\frac{1}{\color{blue}{-1 + x}} + \left(-\frac{x + \left(1 - x\right)}{1 - x}\right)}{-1 - x} \]
    17. +-commutative82.0%

      \[\leadsto \frac{\frac{1}{\color{blue}{x + -1}} + \left(-\frac{x + \left(1 - x\right)}{1 - x}\right)}{-1 - x} \]
    18. associate-+r-82.0%

      \[\leadsto \frac{\frac{1}{x + -1} + \left(-\frac{\color{blue}{\left(x + 1\right) - x}}{1 - x}\right)}{-1 - x} \]
    19. +-commutative82.0%

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

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

    \[\leadsto \frac{\color{blue}{\frac{1}{x + -1} + \left(-\frac{1 + \left(x - x\right)}{1 - x}\right)}}{-1 - x} \]
  9. Step-by-step derivation
    1. +-commutative99.9%

      \[\leadsto \frac{\color{blue}{\left(-\frac{1 + \left(x - x\right)}{1 - x}\right) + \frac{1}{x + -1}}}{-1 - x} \]
    2. neg-sub099.9%

      \[\leadsto \frac{\color{blue}{\left(0 - \frac{1 + \left(x - x\right)}{1 - x}\right)} + \frac{1}{x + -1}}{-1 - x} \]
    3. +-inverses99.9%

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

      \[\leadsto \frac{\left(0 - \frac{\color{blue}{1}}{1 - x}\right) + \frac{1}{x + -1}}{-1 - x} \]
    5. associate-+l-99.9%

      \[\leadsto \frac{\color{blue}{0 - \left(\frac{1}{1 - x} - \frac{1}{x + -1}\right)}}{-1 - x} \]
    6. sub-neg99.9%

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

      \[\leadsto \frac{0 - \left(\frac{1}{\color{blue}{\left(--1\right)} + \left(-x\right)} - \frac{1}{x + -1}\right)}{-1 - x} \]
    8. distribute-neg-in99.9%

      \[\leadsto \frac{0 - \left(\frac{1}{\color{blue}{-\left(-1 + x\right)}} - \frac{1}{x + -1}\right)}{-1 - x} \]
    9. +-commutative99.9%

      \[\leadsto \frac{0 - \left(\frac{1}{-\color{blue}{\left(x + -1\right)}} - \frac{1}{x + -1}\right)}{-1 - x} \]
    10. distribute-neg-frac299.9%

      \[\leadsto \frac{0 - \left(\color{blue}{\left(-\frac{1}{x + -1}\right)} - \frac{1}{x + -1}\right)}{-1 - x} \]
    11. distribute-neg-frac99.9%

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

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

      \[\leadsto \frac{0 - \left(\frac{-1}{x + -1} - \frac{\color{blue}{0 - -1}}{x + -1}\right)}{-1 - x} \]
    14. +-inverses99.9%

      \[\leadsto \frac{0 - \left(\frac{-1}{x + -1} - \frac{\color{blue}{\left(x - x\right)} - -1}{x + -1}\right)}{-1 - x} \]
    15. associate--r+82.0%

      \[\leadsto \frac{0 - \left(\frac{-1}{x + -1} - \frac{\color{blue}{x - \left(x + -1\right)}}{x + -1}\right)}{-1 - x} \]
    16. div-sub82.0%

      \[\leadsto \frac{0 - \color{blue}{\frac{-1 - \left(x - \left(x + -1\right)\right)}{x + -1}}}{-1 - x} \]
    17. associate-+l-79.3%

      \[\leadsto \frac{0 - \frac{\color{blue}{\left(-1 - x\right) + \left(x + -1\right)}}{x + -1}}{-1 - x} \]
  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: 99.6% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 2 \cdot 10^{+15}:\\ \;\;\;\;\frac{2}{\left(1 - x\right) \cdot \left(x + 1\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{2}{x}}{-1 - x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 2e+15) (/ 2.0 (* (- 1.0 x) (+ x 1.0))) (/ (/ 2.0 x) (- -1.0 x))))
double code(double x) {
	double tmp;
	if (x <= 2e+15) {
		tmp = 2.0 / ((1.0 - x) * (x + 1.0));
	} else {
		tmp = (2.0 / x) / (-1.0 - x);
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 2d+15) then
        tmp = 2.0d0 / ((1.0d0 - x) * (x + 1.0d0))
    else
        tmp = (2.0d0 / x) / ((-1.0d0) - x)
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 2e+15) {
		tmp = 2.0 / ((1.0 - x) * (x + 1.0));
	} else {
		tmp = (2.0 / x) / (-1.0 - x);
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 2e+15:
		tmp = 2.0 / ((1.0 - x) * (x + 1.0))
	else:
		tmp = (2.0 / x) / (-1.0 - x)
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 2e+15)
		tmp = Float64(2.0 / Float64(Float64(1.0 - x) * Float64(x + 1.0)));
	else
		tmp = Float64(Float64(2.0 / x) / Float64(-1.0 - x));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 2e+15)
		tmp = 2.0 / ((1.0 - x) * (x + 1.0));
	else
		tmp = (2.0 / x) / (-1.0 - x);
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 2e+15], N[(2.0 / N[(N[(1.0 - x), $MachinePrecision] * N[(x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(2.0 / x), $MachinePrecision] / N[(-1.0 - x), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 2 \cdot 10^{+15}:\\
\;\;\;\;\frac{2}{\left(1 - x\right) \cdot \left(x + 1\right)}\\

\mathbf{else}:\\
\;\;\;\;\frac{\frac{2}{x}}{-1 - x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 2e15

    1. Initial program 84.2%

      \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. sub-neg84.2%

        \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
      2. +-commutative84.2%

        \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
      3. distribute-neg-frac284.2%

        \[\leadsto \color{blue}{\frac{1}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
      4. neg-sub084.2%

        \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
      5. associate-+l-84.2%

        \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
      6. neg-sub084.2%

        \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
      7. remove-double-neg84.2%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{\color{blue}{-\left(-\left(x + 1\right)\right)}} \]
      8. distribute-neg-in84.2%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}} \]
      9. sub-neg84.2%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) - 1\right)}} \]
      10. distribute-neg-frac284.2%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
      11. sub-neg84.2%

        \[\leadsto \color{blue}{\frac{1}{\left(-x\right) + 1} - \frac{1}{\left(-x\right) - 1}} \]
      12. +-commutative84.2%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-x\right)}} - \frac{1}{\left(-x\right) - 1} \]
      13. unsub-neg84.2%

        \[\leadsto \frac{1}{\color{blue}{1 - x}} - \frac{1}{\left(-x\right) - 1} \]
      14. sub-neg84.2%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
      15. +-commutative84.2%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) + \left(-x\right)}} \]
      16. unsub-neg84.2%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) - x}} \]
      17. metadata-eval84.2%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{-1} - x} \]
    3. Simplified84.2%

      \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. sub-neg84.2%

        \[\leadsto \color{blue}{\frac{1}{1 - x} + \left(-\frac{1}{-1 - x}\right)} \]
      2. distribute-neg-frac84.2%

        \[\leadsto \frac{1}{1 - x} + \color{blue}{\frac{-1}{-1 - x}} \]
      3. metadata-eval84.2%

        \[\leadsto \frac{1}{1 - x} + \frac{\color{blue}{-1}}{-1 - x} \]
    6. Applied egg-rr84.2%

      \[\leadsto \color{blue}{\frac{1}{1 - x} + \frac{-1}{-1 - x}} \]
    7. Step-by-step derivation
      1. *-rgt-identity84.2%

        \[\leadsto \color{blue}{\frac{1}{1 - x} \cdot 1} + \frac{-1}{-1 - x} \]
      2. fma-undefine84.2%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{1}{1 - x}, 1, \frac{-1}{-1 - x}\right)} \]
      3. *-inverses84.2%

        \[\leadsto \mathsf{fma}\left(\frac{1}{1 - x}, \color{blue}{\frac{-1 - x}{-1 - x}}, \frac{-1}{-1 - x}\right) \]
      4. *-lft-identity84.2%

        \[\leadsto \mathsf{fma}\left(\frac{1}{1 - x}, \frac{-1 - x}{-1 - x}, \color{blue}{1 \cdot \frac{-1}{-1 - x}}\right) \]
      5. *-inverses84.2%

        \[\leadsto \mathsf{fma}\left(\frac{1}{1 - x}, \frac{-1 - x}{-1 - x}, \color{blue}{\frac{-\left(1 - x\right)}{-\left(1 - x\right)}} \cdot \frac{-1}{-1 - x}\right) \]
      6. distribute-frac-neg84.2%

        \[\leadsto \mathsf{fma}\left(\frac{1}{1 - x}, \frac{-1 - x}{-1 - x}, \color{blue}{\left(-\frac{1 - x}{-\left(1 - x\right)}\right)} \cdot \frac{-1}{-1 - x}\right) \]
      7. distribute-lft-neg-in84.2%

        \[\leadsto \mathsf{fma}\left(\frac{1}{1 - x}, \frac{-1 - x}{-1 - x}, \color{blue}{-\frac{1 - x}{-\left(1 - x\right)} \cdot \frac{-1}{-1 - x}}\right) \]
      8. times-frac69.8%

        \[\leadsto \mathsf{fma}\left(\frac{1}{1 - x}, \frac{-1 - x}{-1 - x}, -\color{blue}{\frac{\left(1 - x\right) \cdot -1}{\left(-\left(1 - x\right)\right) \cdot \left(-1 - x\right)}}\right) \]
      9. distribute-lft-neg-out69.8%

        \[\leadsto \mathsf{fma}\left(\frac{1}{1 - x}, \frac{-1 - x}{-1 - x}, -\frac{\left(1 - x\right) \cdot -1}{\color{blue}{-\left(1 - x\right) \cdot \left(-1 - x\right)}}\right) \]
      10. distribute-rgt-neg-out69.8%

        \[\leadsto \mathsf{fma}\left(\frac{1}{1 - x}, \frac{-1 - x}{-1 - x}, -\frac{\left(1 - x\right) \cdot -1}{\color{blue}{\left(1 - x\right) \cdot \left(-\left(-1 - x\right)\right)}}\right) \]
      11. fma-neg69.8%

        \[\leadsto \color{blue}{\frac{1}{1 - x} \cdot \frac{-1 - x}{-1 - x} - \frac{\left(1 - x\right) \cdot -1}{\left(1 - x\right) \cdot \left(-\left(-1 - x\right)\right)}} \]
    8. Simplified98.6%

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

    if 2e15 < x

    1. Initial program 55.6%

      \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. sub-neg55.6%

        \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
      2. +-commutative55.6%

        \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
      3. distribute-neg-frac255.6%

        \[\leadsto \color{blue}{\frac{1}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
      4. neg-sub055.6%

        \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
      5. associate-+l-55.6%

        \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
      6. neg-sub055.6%

        \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
      7. remove-double-neg55.6%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{\color{blue}{-\left(-\left(x + 1\right)\right)}} \]
      8. distribute-neg-in55.6%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}} \]
      9. sub-neg55.6%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) - 1\right)}} \]
      10. distribute-neg-frac255.6%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
      11. sub-neg55.6%

        \[\leadsto \color{blue}{\frac{1}{\left(-x\right) + 1} - \frac{1}{\left(-x\right) - 1}} \]
      12. +-commutative55.6%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-x\right)}} - \frac{1}{\left(-x\right) - 1} \]
      13. unsub-neg55.6%

        \[\leadsto \frac{1}{\color{blue}{1 - x}} - \frac{1}{\left(-x\right) - 1} \]
      14. sub-neg55.6%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
      15. +-commutative55.6%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) + \left(-x\right)}} \]
      16. unsub-neg55.6%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) - x}} \]
      17. metadata-eval55.6%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{-1} - x} \]
    3. Simplified55.6%

      \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. frac-sub55.6%

        \[\leadsto \color{blue}{\frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\left(1 - x\right) \cdot \left(-1 - x\right)}} \]
      2. *-rgt-identity55.6%

        \[\leadsto \frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\color{blue}{\left(\left(1 - x\right) \cdot 1\right)} \cdot \left(-1 - x\right)} \]
      3. metadata-eval55.6%

        \[\leadsto \frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\left(\left(1 - x\right) \cdot \color{blue}{\frac{1}{1}}\right) \cdot \left(-1 - x\right)} \]
      4. div-inv55.6%

        \[\leadsto \frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\color{blue}{\frac{1 - x}{1}} \cdot \left(-1 - x\right)} \]
      5. associate-/r*55.6%

        \[\leadsto \color{blue}{\frac{\frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\frac{1 - x}{1}}}{-1 - x}} \]
      6. *-un-lft-identity55.6%

        \[\leadsto \frac{\frac{\color{blue}{\left(-1 - x\right)} - \left(1 - x\right) \cdot 1}{\frac{1 - x}{1}}}{-1 - x} \]
      7. metadata-eval55.6%

        \[\leadsto \frac{\frac{\left(-1 - x\right) - \left(1 - x\right) \cdot \color{blue}{\frac{1}{1}}}{\frac{1 - x}{1}}}{-1 - x} \]
      8. div-inv55.6%

        \[\leadsto \frac{\frac{\left(-1 - x\right) - \color{blue}{\frac{1 - x}{1}}}{\frac{1 - x}{1}}}{-1 - x} \]
      9. associate--l-61.5%

        \[\leadsto \frac{\frac{\color{blue}{-1 - \left(x + \frac{1 - x}{1}\right)}}{\frac{1 - x}{1}}}{-1 - x} \]
      10. div-inv61.5%

        \[\leadsto \frac{\frac{-1 - \left(x + \color{blue}{\left(1 - x\right) \cdot \frac{1}{1}}\right)}{\frac{1 - x}{1}}}{-1 - x} \]
      11. metadata-eval61.5%

        \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right) \cdot \color{blue}{1}\right)}{\frac{1 - x}{1}}}{-1 - x} \]
      12. *-rgt-identity61.5%

        \[\leadsto \frac{\frac{-1 - \left(x + \color{blue}{\left(1 - x\right)}\right)}{\frac{1 - x}{1}}}{-1 - x} \]
      13. div-inv61.5%

        \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{\color{blue}{\left(1 - x\right) \cdot \frac{1}{1}}}}{-1 - x} \]
      14. metadata-eval61.5%

        \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{\left(1 - x\right) \cdot \color{blue}{1}}}{-1 - x} \]
      15. *-rgt-identity61.5%

        \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{\color{blue}{1 - x}}}{-1 - x} \]
    6. Applied egg-rr61.5%

      \[\leadsto \color{blue}{\frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{1 - x}}{-1 - x}} \]
    7. Taylor expanded in x around inf 99.8%

      \[\leadsto \frac{\color{blue}{\frac{2}{x}}}{-1 - x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 2 \cdot 10^{+15}:\\ \;\;\;\;\frac{2}{\left(1 - x\right) \cdot \left(x + 1\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{2}{x}}{-1 - x}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 74.2% accurate, 0.9× speedup?

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

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

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


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

    1. Initial program 84.8%

      \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. sub-neg84.8%

        \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
      2. +-commutative84.8%

        \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
      3. distribute-neg-frac284.8%

        \[\leadsto \color{blue}{\frac{1}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
      4. neg-sub084.8%

        \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
      5. associate-+l-84.8%

        \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
      6. neg-sub084.8%

        \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
      7. remove-double-neg84.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{\color{blue}{-\left(-\left(x + 1\right)\right)}} \]
      8. distribute-neg-in84.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}} \]
      9. sub-neg84.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) - 1\right)}} \]
      10. distribute-neg-frac284.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
      11. sub-neg84.8%

        \[\leadsto \color{blue}{\frac{1}{\left(-x\right) + 1} - \frac{1}{\left(-x\right) - 1}} \]
      12. +-commutative84.8%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-x\right)}} - \frac{1}{\left(-x\right) - 1} \]
      13. unsub-neg84.8%

        \[\leadsto \frac{1}{\color{blue}{1 - x}} - \frac{1}{\left(-x\right) - 1} \]
      14. sub-neg84.8%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
      15. +-commutative84.8%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) + \left(-x\right)}} \]
      16. unsub-neg84.8%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) - x}} \]
      17. metadata-eval84.8%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{-1} - x} \]
    3. Simplified84.8%

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

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

    if 1 < x

    1. Initial program 55.5%

      \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. sub-neg55.5%

        \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
      2. +-commutative55.5%

        \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
      3. distribute-neg-frac255.5%

        \[\leadsto \color{blue}{\frac{1}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
      4. neg-sub055.5%

        \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
      5. associate-+l-55.5%

        \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
      6. neg-sub055.5%

        \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
      7. remove-double-neg55.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{\color{blue}{-\left(-\left(x + 1\right)\right)}} \]
      8. distribute-neg-in55.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}} \]
      9. sub-neg55.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) - 1\right)}} \]
      10. distribute-neg-frac255.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
      11. sub-neg55.5%

        \[\leadsto \color{blue}{\frac{1}{\left(-x\right) + 1} - \frac{1}{\left(-x\right) - 1}} \]
      12. +-commutative55.5%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-x\right)}} - \frac{1}{\left(-x\right) - 1} \]
      13. unsub-neg55.5%

        \[\leadsto \frac{1}{\color{blue}{1 - x}} - \frac{1}{\left(-x\right) - 1} \]
      14. sub-neg55.5%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
      15. +-commutative55.5%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) + \left(-x\right)}} \]
      16. unsub-neg55.5%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) - x}} \]
      17. metadata-eval55.5%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{-1} - x} \]
    3. Simplified55.5%

      \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. frac-sub58.7%

        \[\leadsto \color{blue}{\frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\left(1 - x\right) \cdot \left(-1 - x\right)}} \]
      2. *-rgt-identity58.7%

        \[\leadsto \frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\color{blue}{\left(\left(1 - x\right) \cdot 1\right)} \cdot \left(-1 - x\right)} \]
      3. metadata-eval58.7%

        \[\leadsto \frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\left(\left(1 - x\right) \cdot \color{blue}{\frac{1}{1}}\right) \cdot \left(-1 - x\right)} \]
      4. div-inv58.7%

        \[\leadsto \frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\color{blue}{\frac{1 - x}{1}} \cdot \left(-1 - x\right)} \]
      5. associate-/r*58.7%

        \[\leadsto \color{blue}{\frac{\frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\frac{1 - x}{1}}}{-1 - x}} \]
      6. *-un-lft-identity58.7%

        \[\leadsto \frac{\frac{\color{blue}{\left(-1 - x\right)} - \left(1 - x\right) \cdot 1}{\frac{1 - x}{1}}}{-1 - x} \]
      7. metadata-eval58.7%

        \[\leadsto \frac{\frac{\left(-1 - x\right) - \left(1 - x\right) \cdot \color{blue}{\frac{1}{1}}}{\frac{1 - x}{1}}}{-1 - x} \]
      8. div-inv58.7%

        \[\leadsto \frac{\frac{\left(-1 - x\right) - \color{blue}{\frac{1 - x}{1}}}{\frac{1 - x}{1}}}{-1 - x} \]
      9. associate--l-64.2%

        \[\leadsto \frac{\frac{\color{blue}{-1 - \left(x + \frac{1 - x}{1}\right)}}{\frac{1 - x}{1}}}{-1 - x} \]
      10. div-inv64.2%

        \[\leadsto \frac{\frac{-1 - \left(x + \color{blue}{\left(1 - x\right) \cdot \frac{1}{1}}\right)}{\frac{1 - x}{1}}}{-1 - x} \]
      11. metadata-eval64.2%

        \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right) \cdot \color{blue}{1}\right)}{\frac{1 - x}{1}}}{-1 - x} \]
      12. *-rgt-identity64.2%

        \[\leadsto \frac{\frac{-1 - \left(x + \color{blue}{\left(1 - x\right)}\right)}{\frac{1 - x}{1}}}{-1 - x} \]
      13. div-inv64.2%

        \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{\color{blue}{\left(1 - x\right) \cdot \frac{1}{1}}}}{-1 - x} \]
      14. metadata-eval64.2%

        \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{\left(1 - x\right) \cdot \color{blue}{1}}}{-1 - x} \]
      15. *-rgt-identity64.2%

        \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{\color{blue}{1 - x}}}{-1 - x} \]
    6. Applied egg-rr64.2%

      \[\leadsto \color{blue}{\frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{1 - x}}{-1 - x}} \]
    7. Taylor expanded in x around inf 97.6%

      \[\leadsto \frac{\color{blue}{\frac{2}{x}}}{-1 - x} \]
    8. Step-by-step derivation
      1. *-un-lft-identity97.6%

        \[\leadsto \color{blue}{1 \cdot \frac{\frac{2}{x}}{-1 - x}} \]
      2. frac-2neg97.6%

        \[\leadsto 1 \cdot \color{blue}{\frac{-\frac{2}{x}}{-\left(-1 - x\right)}} \]
      3. distribute-neg-frac97.6%

        \[\leadsto 1 \cdot \frac{\color{blue}{\frac{-2}{x}}}{-\left(-1 - x\right)} \]
      4. metadata-eval97.6%

        \[\leadsto 1 \cdot \frac{\frac{\color{blue}{-2}}{x}}{-\left(-1 - x\right)} \]
      5. flip--95.4%

        \[\leadsto 1 \cdot \frac{\frac{-2}{x}}{-\color{blue}{\frac{-1 \cdot -1 - x \cdot x}{-1 + x}}} \]
      6. +-commutative95.4%

        \[\leadsto 1 \cdot \frac{\frac{-2}{x}}{-\frac{-1 \cdot -1 - x \cdot x}{\color{blue}{x + -1}}} \]
      7. distribute-neg-frac295.4%

        \[\leadsto 1 \cdot \frac{\frac{-2}{x}}{\color{blue}{\frac{-1 \cdot -1 - x \cdot x}{-\left(x + -1\right)}}} \]
      8. metadata-eval95.4%

        \[\leadsto 1 \cdot \frac{\frac{-2}{x}}{\frac{\color{blue}{1} - x \cdot x}{-\left(x + -1\right)}} \]
      9. metadata-eval95.4%

        \[\leadsto 1 \cdot \frac{\frac{-2}{x}}{\frac{\color{blue}{1 \cdot 1} - x \cdot x}{-\left(x + -1\right)}} \]
      10. +-commutative95.4%

        \[\leadsto 1 \cdot \frac{\frac{-2}{x}}{\frac{1 \cdot 1 - x \cdot x}{-\color{blue}{\left(-1 + x\right)}}} \]
      11. distribute-neg-in95.4%

        \[\leadsto 1 \cdot \frac{\frac{-2}{x}}{\frac{1 \cdot 1 - x \cdot x}{\color{blue}{\left(--1\right) + \left(-x\right)}}} \]
      12. metadata-eval95.4%

        \[\leadsto 1 \cdot \frac{\frac{-2}{x}}{\frac{1 \cdot 1 - x \cdot x}{\color{blue}{1} + \left(-x\right)}} \]
      13. sub-neg95.4%

        \[\leadsto 1 \cdot \frac{\frac{-2}{x}}{\frac{1 \cdot 1 - x \cdot x}{\color{blue}{1 - x}}} \]
      14. flip-+97.6%

        \[\leadsto 1 \cdot \frac{\frac{-2}{x}}{\color{blue}{1 + x}} \]
      15. +-commutative97.6%

        \[\leadsto 1 \cdot \frac{\frac{-2}{x}}{\color{blue}{x + 1}} \]
    9. Applied egg-rr97.6%

      \[\leadsto \color{blue}{1 \cdot \frac{\frac{-2}{x}}{x + 1}} \]
    10. Step-by-step derivation
      1. *-lft-identity97.6%

        \[\leadsto \color{blue}{\frac{\frac{-2}{x}}{x + 1}} \]
      2. associate-/l/95.4%

        \[\leadsto \color{blue}{\frac{-2}{\left(x + 1\right) \cdot x}} \]
    11. Simplified95.4%

      \[\leadsto \color{blue}{\frac{-2}{\left(x + 1\right) \cdot x}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification73.7%

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

Alternative 4: 74.4% accurate, 0.9× speedup?

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

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

\mathbf{else}:\\
\;\;\;\;\frac{\frac{2}{x}}{-1 - x}\\


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

    1. Initial program 84.8%

      \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. sub-neg84.8%

        \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
      2. +-commutative84.8%

        \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
      3. distribute-neg-frac284.8%

        \[\leadsto \color{blue}{\frac{1}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
      4. neg-sub084.8%

        \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
      5. associate-+l-84.8%

        \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
      6. neg-sub084.8%

        \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
      7. remove-double-neg84.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{\color{blue}{-\left(-\left(x + 1\right)\right)}} \]
      8. distribute-neg-in84.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}} \]
      9. sub-neg84.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) - 1\right)}} \]
      10. distribute-neg-frac284.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
      11. sub-neg84.8%

        \[\leadsto \color{blue}{\frac{1}{\left(-x\right) + 1} - \frac{1}{\left(-x\right) - 1}} \]
      12. +-commutative84.8%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-x\right)}} - \frac{1}{\left(-x\right) - 1} \]
      13. unsub-neg84.8%

        \[\leadsto \frac{1}{\color{blue}{1 - x}} - \frac{1}{\left(-x\right) - 1} \]
      14. sub-neg84.8%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
      15. +-commutative84.8%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) + \left(-x\right)}} \]
      16. unsub-neg84.8%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) - x}} \]
      17. metadata-eval84.8%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{-1} - x} \]
    3. Simplified84.8%

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

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

    if 1 < x

    1. Initial program 55.5%

      \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. sub-neg55.5%

        \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
      2. +-commutative55.5%

        \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
      3. distribute-neg-frac255.5%

        \[\leadsto \color{blue}{\frac{1}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
      4. neg-sub055.5%

        \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
      5. associate-+l-55.5%

        \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
      6. neg-sub055.5%

        \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
      7. remove-double-neg55.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{\color{blue}{-\left(-\left(x + 1\right)\right)}} \]
      8. distribute-neg-in55.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}} \]
      9. sub-neg55.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) - 1\right)}} \]
      10. distribute-neg-frac255.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
      11. sub-neg55.5%

        \[\leadsto \color{blue}{\frac{1}{\left(-x\right) + 1} - \frac{1}{\left(-x\right) - 1}} \]
      12. +-commutative55.5%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-x\right)}} - \frac{1}{\left(-x\right) - 1} \]
      13. unsub-neg55.5%

        \[\leadsto \frac{1}{\color{blue}{1 - x}} - \frac{1}{\left(-x\right) - 1} \]
      14. sub-neg55.5%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
      15. +-commutative55.5%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) + \left(-x\right)}} \]
      16. unsub-neg55.5%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) - x}} \]
      17. metadata-eval55.5%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{-1} - x} \]
    3. Simplified55.5%

      \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. frac-sub58.7%

        \[\leadsto \color{blue}{\frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\left(1 - x\right) \cdot \left(-1 - x\right)}} \]
      2. *-rgt-identity58.7%

        \[\leadsto \frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\color{blue}{\left(\left(1 - x\right) \cdot 1\right)} \cdot \left(-1 - x\right)} \]
      3. metadata-eval58.7%

        \[\leadsto \frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\left(\left(1 - x\right) \cdot \color{blue}{\frac{1}{1}}\right) \cdot \left(-1 - x\right)} \]
      4. div-inv58.7%

        \[\leadsto \frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\color{blue}{\frac{1 - x}{1}} \cdot \left(-1 - x\right)} \]
      5. associate-/r*58.7%

        \[\leadsto \color{blue}{\frac{\frac{1 \cdot \left(-1 - x\right) - \left(1 - x\right) \cdot 1}{\frac{1 - x}{1}}}{-1 - x}} \]
      6. *-un-lft-identity58.7%

        \[\leadsto \frac{\frac{\color{blue}{\left(-1 - x\right)} - \left(1 - x\right) \cdot 1}{\frac{1 - x}{1}}}{-1 - x} \]
      7. metadata-eval58.7%

        \[\leadsto \frac{\frac{\left(-1 - x\right) - \left(1 - x\right) \cdot \color{blue}{\frac{1}{1}}}{\frac{1 - x}{1}}}{-1 - x} \]
      8. div-inv58.7%

        \[\leadsto \frac{\frac{\left(-1 - x\right) - \color{blue}{\frac{1 - x}{1}}}{\frac{1 - x}{1}}}{-1 - x} \]
      9. associate--l-64.2%

        \[\leadsto \frac{\frac{\color{blue}{-1 - \left(x + \frac{1 - x}{1}\right)}}{\frac{1 - x}{1}}}{-1 - x} \]
      10. div-inv64.2%

        \[\leadsto \frac{\frac{-1 - \left(x + \color{blue}{\left(1 - x\right) \cdot \frac{1}{1}}\right)}{\frac{1 - x}{1}}}{-1 - x} \]
      11. metadata-eval64.2%

        \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right) \cdot \color{blue}{1}\right)}{\frac{1 - x}{1}}}{-1 - x} \]
      12. *-rgt-identity64.2%

        \[\leadsto \frac{\frac{-1 - \left(x + \color{blue}{\left(1 - x\right)}\right)}{\frac{1 - x}{1}}}{-1 - x} \]
      13. div-inv64.2%

        \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{\color{blue}{\left(1 - x\right) \cdot \frac{1}{1}}}}{-1 - x} \]
      14. metadata-eval64.2%

        \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{\left(1 - x\right) \cdot \color{blue}{1}}}{-1 - x} \]
      15. *-rgt-identity64.2%

        \[\leadsto \frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{\color{blue}{1 - x}}}{-1 - x} \]
    6. Applied egg-rr64.2%

      \[\leadsto \color{blue}{\frac{\frac{-1 - \left(x + \left(1 - x\right)\right)}{1 - x}}{-1 - x}} \]
    7. Taylor expanded in x around inf 97.6%

      \[\leadsto \frac{\color{blue}{\frac{2}{x}}}{-1 - x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification74.2%

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

Alternative 5: 62.7% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;2\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \end{array} \]
(FPCore (x) :precision binary64 (if (<= x 1.0) 2.0 0.0))
double code(double x) {
	double tmp;
	if (x <= 1.0) {
		tmp = 2.0;
	} else {
		tmp = 0.0;
	}
	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 = 0.0d0
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 1.0) {
		tmp = 2.0;
	} else {
		tmp = 0.0;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 1.0:
		tmp = 2.0
	else:
		tmp = 0.0
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 1.0)
		tmp = 2.0;
	else
		tmp = 0.0;
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 1.0)
		tmp = 2.0;
	else
		tmp = 0.0;
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 1.0], 2.0, 0.0]
\begin{array}{l}

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

\mathbf{else}:\\
\;\;\;\;0\\


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

    1. Initial program 84.8%

      \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. sub-neg84.8%

        \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
      2. +-commutative84.8%

        \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
      3. distribute-neg-frac284.8%

        \[\leadsto \color{blue}{\frac{1}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
      4. neg-sub084.8%

        \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
      5. associate-+l-84.8%

        \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
      6. neg-sub084.8%

        \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
      7. remove-double-neg84.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{\color{blue}{-\left(-\left(x + 1\right)\right)}} \]
      8. distribute-neg-in84.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}} \]
      9. sub-neg84.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) - 1\right)}} \]
      10. distribute-neg-frac284.8%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
      11. sub-neg84.8%

        \[\leadsto \color{blue}{\frac{1}{\left(-x\right) + 1} - \frac{1}{\left(-x\right) - 1}} \]
      12. +-commutative84.8%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-x\right)}} - \frac{1}{\left(-x\right) - 1} \]
      13. unsub-neg84.8%

        \[\leadsto \frac{1}{\color{blue}{1 - x}} - \frac{1}{\left(-x\right) - 1} \]
      14. sub-neg84.8%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
      15. +-commutative84.8%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) + \left(-x\right)}} \]
      16. unsub-neg84.8%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) - x}} \]
      17. metadata-eval84.8%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{-1} - x} \]
    3. Simplified84.8%

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

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

    if 1 < x

    1. Initial program 55.5%

      \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. sub-neg55.5%

        \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
      2. +-commutative55.5%

        \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
      3. distribute-neg-frac255.5%

        \[\leadsto \color{blue}{\frac{1}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
      4. neg-sub055.5%

        \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
      5. associate-+l-55.5%

        \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
      6. neg-sub055.5%

        \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
      7. remove-double-neg55.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{\color{blue}{-\left(-\left(x + 1\right)\right)}} \]
      8. distribute-neg-in55.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}} \]
      9. sub-neg55.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) - 1\right)}} \]
      10. distribute-neg-frac255.5%

        \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
      11. sub-neg55.5%

        \[\leadsto \color{blue}{\frac{1}{\left(-x\right) + 1} - \frac{1}{\left(-x\right) - 1}} \]
      12. +-commutative55.5%

        \[\leadsto \frac{1}{\color{blue}{1 + \left(-x\right)}} - \frac{1}{\left(-x\right) - 1} \]
      13. unsub-neg55.5%

        \[\leadsto \frac{1}{\color{blue}{1 - x}} - \frac{1}{\left(-x\right) - 1} \]
      14. sub-neg55.5%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
      15. +-commutative55.5%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) + \left(-x\right)}} \]
      16. unsub-neg55.5%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) - x}} \]
      17. metadata-eval55.5%

        \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{-1} - x} \]
    3. Simplified55.5%

      \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. flip--9.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1 \cdot 1 - x \cdot x}{1 + x}}} - \frac{1}{-1 - x} \]
      2. metadata-eval9.7%

        \[\leadsto \frac{1}{\frac{\color{blue}{1} - x \cdot x}{1 + x}} - \frac{1}{-1 - x} \]
      3. metadata-eval9.7%

        \[\leadsto \frac{1}{\frac{\color{blue}{-1 \cdot -1} - x \cdot x}{1 + x}} - \frac{1}{-1 - x} \]
      4. associate-/r/9.5%

        \[\leadsto \color{blue}{\frac{1}{-1 \cdot -1 - x \cdot x} \cdot \left(1 + x\right)} - \frac{1}{-1 - x} \]
      5. metadata-eval9.5%

        \[\leadsto \frac{1}{\color{blue}{1} - x \cdot x} \cdot \left(1 + x\right) - \frac{1}{-1 - x} \]
      6. pow29.5%

        \[\leadsto \frac{1}{1 - \color{blue}{{x}^{2}}} \cdot \left(1 + x\right) - \frac{1}{-1 - x} \]
    6. Applied egg-rr9.5%

      \[\leadsto \color{blue}{\frac{1}{1 - {x}^{2}} \cdot \left(1 + x\right)} - \frac{1}{-1 - x} \]
    7. Step-by-step derivation
      1. associate-*l/9.6%

        \[\leadsto \color{blue}{\frac{1 \cdot \left(1 + x\right)}{1 - {x}^{2}}} - \frac{1}{-1 - x} \]
      2. *-lft-identity9.6%

        \[\leadsto \frac{\color{blue}{1 + x}}{1 - {x}^{2}} - \frac{1}{-1 - x} \]
      3. +-commutative9.6%

        \[\leadsto \frac{\color{blue}{x + 1}}{1 - {x}^{2}} - \frac{1}{-1 - x} \]
    8. Simplified9.6%

      \[\leadsto \color{blue}{\frac{x + 1}{1 - {x}^{2}}} - \frac{1}{-1 - x} \]
    9. Applied egg-rr0.0%

      \[\leadsto \color{blue}{\frac{1 - {\left(1 + \left(x - x\right)\right)}^{2}}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)}} \]
    10. Step-by-step derivation
      1. div-sub0.0%

        \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} - \frac{{\left(1 + \left(x - x\right)\right)}^{2}}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)}} \]
      2. unpow20.0%

        \[\leadsto \frac{1}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} - \frac{\color{blue}{\left(1 + \left(x - x\right)\right) \cdot \left(1 + \left(x - x\right)\right)}}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} \]
      3. +-inverses0.0%

        \[\leadsto \frac{1}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} - \frac{\left(1 + \color{blue}{0}\right) \cdot \left(1 + \left(x - x\right)\right)}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} \]
      4. metadata-eval0.0%

        \[\leadsto \frac{1}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} - \frac{\color{blue}{1} \cdot \left(1 + \left(x - x\right)\right)}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} \]
      5. +-inverses0.0%

        \[\leadsto \frac{1}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} - \frac{1 \cdot \left(1 + \color{blue}{0}\right)}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} \]
      6. metadata-eval0.0%

        \[\leadsto \frac{1}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} - \frac{1 \cdot \color{blue}{1}}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} \]
      7. metadata-eval0.0%

        \[\leadsto \frac{1}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} - \frac{\color{blue}{1}}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} \]
      8. +-inverses52.0%

        \[\leadsto \color{blue}{0} \]
    11. Simplified52.0%

      \[\leadsto \color{blue}{0} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification63.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;2\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 26.9% accurate, 11.0× speedup?

\[\begin{array}{l} \\ 0 \end{array} \]
(FPCore (x) :precision binary64 0.0)
double code(double x) {
	return 0.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 0.0d0
end function
public static double code(double x) {
	return 0.0;
}
def code(x):
	return 0.0
function code(x)
	return 0.0
end
function tmp = code(x)
	tmp = 0.0;
end
code[x_] := 0.0
\begin{array}{l}

\\
0
\end{array}
Derivation
  1. Initial program 78.2%

    \[\frac{1}{x + 1} - \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. sub-neg78.2%

      \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\frac{1}{x - 1}\right)} \]
    2. +-commutative78.2%

      \[\leadsto \color{blue}{\left(-\frac{1}{x - 1}\right) + \frac{1}{x + 1}} \]
    3. distribute-neg-frac278.2%

      \[\leadsto \color{blue}{\frac{1}{-\left(x - 1\right)}} + \frac{1}{x + 1} \]
    4. neg-sub078.2%

      \[\leadsto \frac{1}{\color{blue}{0 - \left(x - 1\right)}} + \frac{1}{x + 1} \]
    5. associate-+l-78.2%

      \[\leadsto \frac{1}{\color{blue}{\left(0 - x\right) + 1}} + \frac{1}{x + 1} \]
    6. neg-sub078.2%

      \[\leadsto \frac{1}{\color{blue}{\left(-x\right)} + 1} + \frac{1}{x + 1} \]
    7. remove-double-neg78.2%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{\color{blue}{-\left(-\left(x + 1\right)\right)}} \]
    8. distribute-neg-in78.2%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}} \]
    9. sub-neg78.2%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \frac{1}{-\color{blue}{\left(\left(-x\right) - 1\right)}} \]
    10. distribute-neg-frac278.2%

      \[\leadsto \frac{1}{\left(-x\right) + 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)} \]
    11. sub-neg78.2%

      \[\leadsto \color{blue}{\frac{1}{\left(-x\right) + 1} - \frac{1}{\left(-x\right) - 1}} \]
    12. +-commutative78.2%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(-x\right)}} - \frac{1}{\left(-x\right) - 1} \]
    13. unsub-neg78.2%

      \[\leadsto \frac{1}{\color{blue}{1 - x}} - \frac{1}{\left(-x\right) - 1} \]
    14. sub-neg78.2%

      \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-x\right) + \left(-1\right)}} \]
    15. +-commutative78.2%

      \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) + \left(-x\right)}} \]
    16. unsub-neg78.2%

      \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{\left(-1\right) - x}} \]
    17. metadata-eval78.2%

      \[\leadsto \frac{1}{1 - x} - \frac{1}{\color{blue}{-1} - x} \]
  3. Simplified78.2%

    \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. flip--56.5%

      \[\leadsto \frac{1}{\color{blue}{\frac{1 \cdot 1 - x \cdot x}{1 + x}}} - \frac{1}{-1 - x} \]
    2. metadata-eval56.5%

      \[\leadsto \frac{1}{\frac{\color{blue}{1} - x \cdot x}{1 + x}} - \frac{1}{-1 - x} \]
    3. metadata-eval56.5%

      \[\leadsto \frac{1}{\frac{\color{blue}{-1 \cdot -1} - x \cdot x}{1 + x}} - \frac{1}{-1 - x} \]
    4. associate-/r/56.4%

      \[\leadsto \color{blue}{\frac{1}{-1 \cdot -1 - x \cdot x} \cdot \left(1 + x\right)} - \frac{1}{-1 - x} \]
    5. metadata-eval56.4%

      \[\leadsto \frac{1}{\color{blue}{1} - x \cdot x} \cdot \left(1 + x\right) - \frac{1}{-1 - x} \]
    6. pow256.4%

      \[\leadsto \frac{1}{1 - \color{blue}{{x}^{2}}} \cdot \left(1 + x\right) - \frac{1}{-1 - x} \]
  6. Applied egg-rr56.4%

    \[\leadsto \color{blue}{\frac{1}{1 - {x}^{2}} \cdot \left(1 + x\right)} - \frac{1}{-1 - x} \]
  7. Step-by-step derivation
    1. associate-*l/56.5%

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

      \[\leadsto \frac{\color{blue}{1 + x}}{1 - {x}^{2}} - \frac{1}{-1 - x} \]
    3. +-commutative56.5%

      \[\leadsto \frac{\color{blue}{x + 1}}{1 - {x}^{2}} - \frac{1}{-1 - x} \]
  8. Simplified56.5%

    \[\leadsto \color{blue}{\frac{x + 1}{1 - {x}^{2}}} - \frac{1}{-1 - x} \]
  9. Applied egg-rr1.6%

    \[\leadsto \color{blue}{\frac{1 - {\left(1 + \left(x - x\right)\right)}^{2}}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)}} \]
  10. Step-by-step derivation
    1. div-sub1.6%

      \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} - \frac{{\left(1 + \left(x - x\right)\right)}^{2}}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)}} \]
    2. unpow21.6%

      \[\leadsto \frac{1}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} - \frac{\color{blue}{\left(1 + \left(x - x\right)\right) \cdot \left(1 + \left(x - x\right)\right)}}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} \]
    3. +-inverses1.6%

      \[\leadsto \frac{1}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} - \frac{\left(1 + \color{blue}{0}\right) \cdot \left(1 + \left(x - x\right)\right)}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} \]
    4. metadata-eval1.6%

      \[\leadsto \frac{1}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} - \frac{\color{blue}{1} \cdot \left(1 + \left(x - x\right)\right)}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} \]
    5. +-inverses1.6%

      \[\leadsto \frac{1}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} - \frac{1 \cdot \left(1 + \color{blue}{0}\right)}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} \]
    6. metadata-eval1.6%

      \[\leadsto \frac{1}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} - \frac{1 \cdot \color{blue}{1}}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} \]
    7. metadata-eval1.6%

      \[\leadsto \frac{1}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} - \frac{\color{blue}{1}}{\mathsf{fma}\left(x, x, -1\right) \cdot \left(\left(-1 + \left(1 + x\right)\right) - x\right)} \]
    8. +-inverses26.3%

      \[\leadsto \color{blue}{0} \]
  11. Simplified26.3%

    \[\leadsto \color{blue}{0} \]
  12. Final simplification26.3%

    \[\leadsto 0 \]
  13. Add Preprocessing

Reproduce

?
herbie shell --seed 2024050 
(FPCore (x)
  :name "Asymptote A"
  :precision binary64
  (- (/ 1.0 (+ x 1.0)) (/ 1.0 (- x 1.0))))