3frac (problem 3.3.3)

Percentage Accurate: 70.1% → 99.7%
Time: 11.6s
Alternatives: 11
Speedup: 1.7×

Specification

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

\\
\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \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 11 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: 70.1% accurate, 1.0× speedup?

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

\\
\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1}
\end{array}

Alternative 1: 99.7% accurate, 0.0× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(2, {x}^{-2}, \mathsf{fma}\left(2, {x}^{-4}, 2\right)\right) \cdot {x}^{-3} \end{array} \]
(FPCore (x)
 :precision binary64
 (* (fma 2.0 (pow x -2.0) (fma 2.0 (pow x -4.0) 2.0)) (pow x -3.0)))
double code(double x) {
	return fma(2.0, pow(x, -2.0), fma(2.0, pow(x, -4.0), 2.0)) * pow(x, -3.0);
}
function code(x)
	return Float64(fma(2.0, (x ^ -2.0), fma(2.0, (x ^ -4.0), 2.0)) * (x ^ -3.0))
end
code[x_] := N[(N[(2.0 * N[Power[x, -2.0], $MachinePrecision] + N[(2.0 * N[Power[x, -4.0], $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision] * N[Power[x, -3.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(2, {x}^{-2}, \mathsf{fma}\left(2, {x}^{-4}, 2\right)\right) \cdot {x}^{-3}
\end{array}
Derivation
  1. Initial program 70.6%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative70.6%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-70.5%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg70.5%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg70.5%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub070.5%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-70.5%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub070.5%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac270.5%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg270.5%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+70.6%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative70.6%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg70.6%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac270.6%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg70.6%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-70.6%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub070.6%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified70.6%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 98.6%

    \[\leadsto \color{blue}{\frac{2 + \left(2 \cdot \frac{1}{{x}^{2}} + \frac{2}{{x}^{4}}\right)}{{x}^{3}}} \]
  6. Step-by-step derivation
    1. associate-+r+98.6%

      \[\leadsto \frac{\color{blue}{\left(2 + 2 \cdot \frac{1}{{x}^{2}}\right) + \frac{2}{{x}^{4}}}}{{x}^{3}} \]
    2. +-commutative98.6%

      \[\leadsto \frac{\color{blue}{\left(2 \cdot \frac{1}{{x}^{2}} + 2\right)} + \frac{2}{{x}^{4}}}{{x}^{3}} \]
    3. associate-+l+98.6%

      \[\leadsto \frac{\color{blue}{2 \cdot \frac{1}{{x}^{2}} + \left(2 + \frac{2}{{x}^{4}}\right)}}{{x}^{3}} \]
    4. associate-*r/98.6%

      \[\leadsto \frac{\color{blue}{\frac{2 \cdot 1}{{x}^{2}}} + \left(2 + \frac{2}{{x}^{4}}\right)}{{x}^{3}} \]
    5. metadata-eval98.6%

      \[\leadsto \frac{\frac{\color{blue}{2}}{{x}^{2}} + \left(2 + \frac{2}{{x}^{4}}\right)}{{x}^{3}} \]
  7. Simplified98.6%

    \[\leadsto \color{blue}{\frac{\frac{2}{{x}^{2}} + \left(2 + \frac{2}{{x}^{4}}\right)}{{x}^{3}}} \]
  8. Step-by-step derivation
    1. div-inv98.6%

      \[\leadsto \color{blue}{\left(\frac{2}{{x}^{2}} + \left(2 + \frac{2}{{x}^{4}}\right)\right) \cdot \frac{1}{{x}^{3}}} \]
    2. div-inv98.6%

      \[\leadsto \left(\color{blue}{2 \cdot \frac{1}{{x}^{2}}} + \left(2 + \frac{2}{{x}^{4}}\right)\right) \cdot \frac{1}{{x}^{3}} \]
    3. fma-define98.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(2, \frac{1}{{x}^{2}}, 2 + \frac{2}{{x}^{4}}\right)} \cdot \frac{1}{{x}^{3}} \]
    4. pow-flip98.6%

      \[\leadsto \mathsf{fma}\left(2, \color{blue}{{x}^{\left(-2\right)}}, 2 + \frac{2}{{x}^{4}}\right) \cdot \frac{1}{{x}^{3}} \]
    5. metadata-eval98.6%

      \[\leadsto \mathsf{fma}\left(2, {x}^{\color{blue}{-2}}, 2 + \frac{2}{{x}^{4}}\right) \cdot \frac{1}{{x}^{3}} \]
    6. +-commutative98.6%

      \[\leadsto \mathsf{fma}\left(2, {x}^{-2}, \color{blue}{\frac{2}{{x}^{4}} + 2}\right) \cdot \frac{1}{{x}^{3}} \]
    7. div-inv98.6%

      \[\leadsto \mathsf{fma}\left(2, {x}^{-2}, \color{blue}{2 \cdot \frac{1}{{x}^{4}}} + 2\right) \cdot \frac{1}{{x}^{3}} \]
    8. fma-define98.6%

      \[\leadsto \mathsf{fma}\left(2, {x}^{-2}, \color{blue}{\mathsf{fma}\left(2, \frac{1}{{x}^{4}}, 2\right)}\right) \cdot \frac{1}{{x}^{3}} \]
    9. pow-flip98.6%

      \[\leadsto \mathsf{fma}\left(2, {x}^{-2}, \mathsf{fma}\left(2, \color{blue}{{x}^{\left(-4\right)}}, 2\right)\right) \cdot \frac{1}{{x}^{3}} \]
    10. metadata-eval98.6%

      \[\leadsto \mathsf{fma}\left(2, {x}^{-2}, \mathsf{fma}\left(2, {x}^{\color{blue}{-4}}, 2\right)\right) \cdot \frac{1}{{x}^{3}} \]
    11. pow-flip99.7%

      \[\leadsto \mathsf{fma}\left(2, {x}^{-2}, \mathsf{fma}\left(2, {x}^{-4}, 2\right)\right) \cdot \color{blue}{{x}^{\left(-3\right)}} \]
    12. metadata-eval99.7%

      \[\leadsto \mathsf{fma}\left(2, {x}^{-2}, \mathsf{fma}\left(2, {x}^{-4}, 2\right)\right) \cdot {x}^{\color{blue}{-3}} \]
  9. Applied egg-rr99.7%

    \[\leadsto \color{blue}{\mathsf{fma}\left(2, {x}^{-2}, \mathsf{fma}\left(2, {x}^{-4}, 2\right)\right) \cdot {x}^{-3}} \]
  10. Final simplification99.7%

    \[\leadsto \mathsf{fma}\left(2, {x}^{-2}, \mathsf{fma}\left(2, {x}^{-4}, 2\right)\right) \cdot {x}^{-3} \]
  11. Add Preprocessing

Alternative 2: 99.0% accurate, 0.1× speedup?

\[\begin{array}{l} \\ 2 \cdot {x}^{-3} \end{array} \]
(FPCore (x) :precision binary64 (* 2.0 (pow x -3.0)))
double code(double x) {
	return 2.0 * pow(x, -3.0);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 2.0d0 * (x ** (-3.0d0))
end function
public static double code(double x) {
	return 2.0 * Math.pow(x, -3.0);
}
def code(x):
	return 2.0 * math.pow(x, -3.0)
function code(x)
	return Float64(2.0 * (x ^ -3.0))
end
function tmp = code(x)
	tmp = 2.0 * (x ^ -3.0);
end
code[x_] := N[(2.0 * N[Power[x, -3.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
2 \cdot {x}^{-3}
\end{array}
Derivation
  1. Initial program 70.6%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative70.6%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-70.5%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg70.5%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg70.5%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub070.5%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-70.5%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub070.5%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac270.5%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg270.5%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+70.6%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative70.6%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg70.6%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac270.6%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg70.6%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-70.6%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub070.6%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified70.6%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 97.9%

    \[\leadsto \color{blue}{\frac{2}{{x}^{3}}} \]
  6. Step-by-step derivation
    1. div-inv97.9%

      \[\leadsto \color{blue}{2 \cdot \frac{1}{{x}^{3}}} \]
    2. pow-flip99.0%

      \[\leadsto 2 \cdot \color{blue}{{x}^{\left(-3\right)}} \]
    3. metadata-eval99.0%

      \[\leadsto 2 \cdot {x}^{\color{blue}{-3}} \]
  7. Applied egg-rr99.0%

    \[\leadsto \color{blue}{2 \cdot {x}^{-3}} \]
  8. Final simplification99.0%

    \[\leadsto 2 \cdot {x}^{-3} \]
  9. Add Preprocessing

Alternative 3: 74.1% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(1 - x\right) \cdot \left(x + 1\right)\\ \mathbf{if}\;\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x + -1} \leq 5 \cdot 10^{-25}:\\ \;\;\;\;\frac{\frac{\frac{1}{x}}{x + -1}}{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{-2 \cdot t\_0 - x \cdot \left(x + x\right)}{x \cdot t\_0}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (* (- 1.0 x) (+ x 1.0))))
   (if (<= (+ (- (/ 1.0 (+ x 1.0)) (/ 2.0 x)) (/ 1.0 (+ x -1.0))) 5e-25)
     (/ (/ (/ 1.0 x) (+ x -1.0)) x)
     (/ (- (* -2.0 t_0) (* x (+ x x))) (* x t_0)))))
double code(double x) {
	double t_0 = (1.0 - x) * (x + 1.0);
	double tmp;
	if ((((1.0 / (x + 1.0)) - (2.0 / x)) + (1.0 / (x + -1.0))) <= 5e-25) {
		tmp = ((1.0 / x) / (x + -1.0)) / x;
	} else {
		tmp = ((-2.0 * t_0) - (x * (x + x))) / (x * t_0);
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (1.0d0 - x) * (x + 1.0d0)
    if ((((1.0d0 / (x + 1.0d0)) - (2.0d0 / x)) + (1.0d0 / (x + (-1.0d0)))) <= 5d-25) then
        tmp = ((1.0d0 / x) / (x + (-1.0d0))) / x
    else
        tmp = (((-2.0d0) * t_0) - (x * (x + x))) / (x * t_0)
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = (1.0 - x) * (x + 1.0);
	double tmp;
	if ((((1.0 / (x + 1.0)) - (2.0 / x)) + (1.0 / (x + -1.0))) <= 5e-25) {
		tmp = ((1.0 / x) / (x + -1.0)) / x;
	} else {
		tmp = ((-2.0 * t_0) - (x * (x + x))) / (x * t_0);
	}
	return tmp;
}
def code(x):
	t_0 = (1.0 - x) * (x + 1.0)
	tmp = 0
	if (((1.0 / (x + 1.0)) - (2.0 / x)) + (1.0 / (x + -1.0))) <= 5e-25:
		tmp = ((1.0 / x) / (x + -1.0)) / x
	else:
		tmp = ((-2.0 * t_0) - (x * (x + x))) / (x * t_0)
	return tmp
function code(x)
	t_0 = Float64(Float64(1.0 - x) * Float64(x + 1.0))
	tmp = 0.0
	if (Float64(Float64(Float64(1.0 / Float64(x + 1.0)) - Float64(2.0 / x)) + Float64(1.0 / Float64(x + -1.0))) <= 5e-25)
		tmp = Float64(Float64(Float64(1.0 / x) / Float64(x + -1.0)) / x);
	else
		tmp = Float64(Float64(Float64(-2.0 * t_0) - Float64(x * Float64(x + x))) / Float64(x * t_0));
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = (1.0 - x) * (x + 1.0);
	tmp = 0.0;
	if ((((1.0 / (x + 1.0)) - (2.0 / x)) + (1.0 / (x + -1.0))) <= 5e-25)
		tmp = ((1.0 / x) / (x + -1.0)) / x;
	else
		tmp = ((-2.0 * t_0) - (x * (x + x))) / (x * t_0);
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(N[(1.0 - x), $MachinePrecision] * N[(x + 1.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(N[(1.0 / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] - N[(2.0 / x), $MachinePrecision]), $MachinePrecision] + N[(1.0 / N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 5e-25], N[(N[(N[(1.0 / x), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision], N[(N[(N[(-2.0 * t$95$0), $MachinePrecision] - N[(x * N[(x + x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(x * t$95$0), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(1 - x\right) \cdot \left(x + 1\right)\\
\mathbf{if}\;\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x + -1} \leq 5 \cdot 10^{-25}:\\
\;\;\;\;\frac{\frac{\frac{1}{x}}{x + -1}}{x}\\

\mathbf{else}:\\
\;\;\;\;\frac{-2 \cdot t\_0 - x \cdot \left(x + x\right)}{x \cdot t\_0}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (-.f64 (/.f64 #s(literal 1 binary64) (+.f64 x #s(literal 1 binary64))) (/.f64 #s(literal 2 binary64) x)) (/.f64 #s(literal 1 binary64) (-.f64 x #s(literal 1 binary64)))) < 4.99999999999999962e-25

    1. Initial program 70.7%

      \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. +-commutative70.7%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
      2. associate-+r-70.6%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
      3. sub-neg70.6%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
      4. remove-double-neg70.6%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      5. neg-sub070.6%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      6. associate-+l-70.6%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      7. neg-sub070.6%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      8. distribute-neg-frac270.6%

        \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
      9. distribute-frac-neg270.6%

        \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
      10. associate-+r+70.7%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
      11. +-commutative70.7%

        \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
      12. remove-double-neg70.7%

        \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      13. distribute-neg-frac270.7%

        \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      14. sub0-neg70.7%

        \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      15. associate-+l-70.7%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      16. neg-sub070.7%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    3. Simplified70.7%

      \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 70.4%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{-1 \cdot \frac{1 + \frac{1}{x}}{x}} \]
    6. Step-by-step derivation
      1. associate-*r/70.4%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1 \cdot \left(1 + \frac{1}{x}\right)}{x}} \]
      2. neg-mul-170.4%

        \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{-\left(1 + \frac{1}{x}\right)}}{x} \]
      3. distribute-neg-in70.4%

        \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{\left(-1\right) + \left(-\frac{1}{x}\right)}}{x} \]
      4. metadata-eval70.4%

        \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{-1} + \left(-\frac{1}{x}\right)}{x} \]
      5. distribute-neg-frac70.4%

        \[\leadsto \frac{1}{x + -1} + \frac{-1 + \color{blue}{\frac{-1}{x}}}{x} \]
      6. metadata-eval70.4%

        \[\leadsto \frac{1}{x + -1} + \frac{-1 + \frac{\color{blue}{-1}}{x}}{x} \]
    7. Simplified70.4%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1 + \frac{-1}{x}}{x}} \]
    8. Step-by-step derivation
      1. frac-2neg70.4%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-\left(-1 + \frac{-1}{x}\right)}{-x}} \]
      2. div-inv70.5%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(-\left(-1 + \frac{-1}{x}\right)\right) \cdot \frac{1}{-x}} \]
      3. +-commutative70.5%

        \[\leadsto \frac{1}{x + -1} + \left(-\color{blue}{\left(\frac{-1}{x} + -1\right)}\right) \cdot \frac{1}{-x} \]
      4. add-sqr-sqrt35.0%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\color{blue}{\sqrt{\frac{-1}{x}} \cdot \sqrt{\frac{-1}{x}}} + -1\right)\right) \cdot \frac{1}{-x} \]
      5. sqrt-unprod70.6%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\color{blue}{\sqrt{\frac{-1}{x} \cdot \frac{-1}{x}}} + -1\right)\right) \cdot \frac{1}{-x} \]
      6. frac-times70.6%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\sqrt{\color{blue}{\frac{-1 \cdot -1}{x \cdot x}}} + -1\right)\right) \cdot \frac{1}{-x} \]
      7. metadata-eval70.6%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\sqrt{\frac{\color{blue}{1}}{x \cdot x}} + -1\right)\right) \cdot \frac{1}{-x} \]
      8. metadata-eval70.6%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\sqrt{\frac{\color{blue}{1 \cdot 1}}{x \cdot x}} + -1\right)\right) \cdot \frac{1}{-x} \]
      9. frac-times70.6%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\sqrt{\color{blue}{\frac{1}{x} \cdot \frac{1}{x}}} + -1\right)\right) \cdot \frac{1}{-x} \]
      10. sqrt-prod35.6%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\color{blue}{\sqrt{\frac{1}{x}} \cdot \sqrt{\frac{1}{x}}} + -1\right)\right) \cdot \frac{1}{-x} \]
      11. add-sqr-sqrt70.4%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\color{blue}{\frac{1}{x}} + -1\right)\right) \cdot \frac{1}{-x} \]
      12. metadata-eval70.4%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \frac{\color{blue}{--1}}{-x} \]
      13. frac-2neg70.4%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \color{blue}{\frac{-1}{x}} \]
      14. add-sqr-sqrt17.6%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \color{blue}{\left(\sqrt{\frac{-1}{x}} \cdot \sqrt{\frac{-1}{x}}\right)} \]
      15. sqrt-unprod16.2%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \color{blue}{\sqrt{\frac{-1}{x} \cdot \frac{-1}{x}}} \]
      16. frac-times13.1%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \sqrt{\color{blue}{\frac{-1 \cdot -1}{x \cdot x}}} \]
      17. metadata-eval13.1%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \sqrt{\frac{\color{blue}{1}}{x \cdot x}} \]
      18. metadata-eval13.1%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \sqrt{\frac{\color{blue}{1 \cdot 1}}{x \cdot x}} \]
      19. frac-times16.2%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \sqrt{\color{blue}{\frac{1}{x} \cdot \frac{1}{x}}} \]
      20. sqrt-prod3.2%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \color{blue}{\left(\sqrt{\frac{1}{x}} \cdot \sqrt{\frac{1}{x}}\right)} \]
      21. add-sqr-sqrt6.3%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \color{blue}{\frac{1}{x}} \]
    9. Applied egg-rr6.3%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(-\left(\frac{1}{x} + -1\right)\right) \cdot \frac{1}{x}} \]
    10. Step-by-step derivation
      1. add-sqr-sqrt6.3%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(\sqrt{-\left(\frac{1}{x} + -1\right)} \cdot \sqrt{-\left(\frac{1}{x} + -1\right)}\right)} \cdot \frac{1}{x} \]
      2. sqrt-unprod6.3%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\sqrt{\left(-\left(\frac{1}{x} + -1\right)\right) \cdot \left(-\left(\frac{1}{x} + -1\right)\right)}} \cdot \frac{1}{x} \]
      3. sqr-neg6.3%

        \[\leadsto \frac{1}{x + -1} + \sqrt{\color{blue}{\left(\frac{1}{x} + -1\right) \cdot \left(\frac{1}{x} + -1\right)}} \cdot \frac{1}{x} \]
      4. sqrt-unprod0.0%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(\sqrt{\frac{1}{x} + -1} \cdot \sqrt{\frac{1}{x} + -1}\right)} \cdot \frac{1}{x} \]
      5. add-sqr-sqrt70.4%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(\frac{1}{x} + -1\right)} \cdot \frac{1}{x} \]
      6. cancel-sign-sub70.4%

        \[\leadsto \color{blue}{\frac{1}{x + -1} - \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \frac{1}{x}} \]
      7. un-div-inv70.4%

        \[\leadsto \frac{1}{x + -1} - \color{blue}{\frac{-\left(\frac{1}{x} + -1\right)}{x}} \]
      8. frac-sub70.4%

        \[\leadsto \color{blue}{\frac{1 \cdot x - \left(x + -1\right) \cdot \left(-\left(\frac{1}{x} + -1\right)\right)}{\left(x + -1\right) \cdot x}} \]
    11. Applied egg-rr70.5%

      \[\leadsto \color{blue}{\frac{x - \left(x + -1\right) \cdot \left(1 + \frac{1}{x}\right)}{\left(x + -1\right) \cdot x}} \]
    12. Step-by-step derivation
      1. associate-/r*70.5%

        \[\leadsto \color{blue}{\frac{\frac{x - \left(x + -1\right) \cdot \left(1 + \frac{1}{x}\right)}{x + -1}}{x}} \]
    13. Simplified74.4%

      \[\leadsto \color{blue}{\frac{\frac{\frac{1}{x}}{x + -1}}{x}} \]

    if 4.99999999999999962e-25 < (+.f64 (-.f64 (/.f64 #s(literal 1 binary64) (+.f64 x #s(literal 1 binary64))) (/.f64 #s(literal 2 binary64) x)) (/.f64 #s(literal 1 binary64) (-.f64 x #s(literal 1 binary64))))

    1. Initial program 66.7%

      \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. +-commutative66.7%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
      2. associate-+r-66.2%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
      3. sub-neg66.2%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
      4. remove-double-neg66.2%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      5. neg-sub066.2%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      6. associate-+l-66.2%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      7. neg-sub066.2%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      8. distribute-neg-frac266.2%

        \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
      9. distribute-frac-neg266.2%

        \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
      10. associate-+r+66.7%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
      11. +-commutative66.7%

        \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
      12. remove-double-neg66.7%

        \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      13. distribute-neg-frac266.7%

        \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      14. sub0-neg66.7%

        \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      15. associate-+l-66.7%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      16. neg-sub066.7%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    3. Simplified66.7%

      \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. +-commutative66.7%

        \[\leadsto \color{blue}{\left(\frac{-2}{x} - \frac{1}{-1 - x}\right) + \frac{1}{x + -1}} \]
      2. associate-+l-66.2%

        \[\leadsto \color{blue}{\frac{-2}{x} - \left(\frac{1}{-1 - x} - \frac{1}{x + -1}\right)} \]
    6. Applied egg-rr66.2%

      \[\leadsto \color{blue}{\frac{-2}{x} - \left(\frac{1}{-1 - x} - \frac{1}{x + -1}\right)} \]
    7. Step-by-step derivation
      1. frac-sub65.7%

        \[\leadsto \frac{-2}{x} - \color{blue}{\frac{1 \cdot \left(x + -1\right) - \left(-1 - x\right) \cdot 1}{\left(-1 - x\right) \cdot \left(x + -1\right)}} \]
      2. frac-sub99.5%

        \[\leadsto \color{blue}{\frac{-2 \cdot \left(\left(-1 - x\right) \cdot \left(x + -1\right)\right) - x \cdot \left(1 \cdot \left(x + -1\right) - \left(-1 - x\right) \cdot 1\right)}{x \cdot \left(\left(-1 - x\right) \cdot \left(x + -1\right)\right)}} \]
      3. *-un-lft-identity99.5%

        \[\leadsto \frac{-2 \cdot \left(\left(-1 - x\right) \cdot \left(x + -1\right)\right) - x \cdot \left(\color{blue}{\left(x + -1\right)} - \left(-1 - x\right) \cdot 1\right)}{x \cdot \left(\left(-1 - x\right) \cdot \left(x + -1\right)\right)} \]
      4. metadata-eval99.5%

        \[\leadsto \frac{-2 \cdot \left(\left(-1 - x\right) \cdot \left(x + -1\right)\right) - x \cdot \left(\left(x + -1\right) - \left(-1 - x\right) \cdot \color{blue}{\frac{1}{1}}\right)}{x \cdot \left(\left(-1 - x\right) \cdot \left(x + -1\right)\right)} \]
      5. div-inv99.5%

        \[\leadsto \frac{-2 \cdot \left(\left(-1 - x\right) \cdot \left(x + -1\right)\right) - x \cdot \left(\left(x + -1\right) - \color{blue}{\frac{-1 - x}{1}}\right)}{x \cdot \left(\left(-1 - x\right) \cdot \left(x + -1\right)\right)} \]
      6. associate--l+99.5%

        \[\leadsto \frac{-2 \cdot \left(\left(-1 - x\right) \cdot \left(x + -1\right)\right) - x \cdot \color{blue}{\left(x + \left(-1 - \frac{-1 - x}{1}\right)\right)}}{x \cdot \left(\left(-1 - x\right) \cdot \left(x + -1\right)\right)} \]
      7. div-inv99.5%

        \[\leadsto \frac{-2 \cdot \left(\left(-1 - x\right) \cdot \left(x + -1\right)\right) - x \cdot \left(x + \left(-1 - \color{blue}{\left(-1 - x\right) \cdot \frac{1}{1}}\right)\right)}{x \cdot \left(\left(-1 - x\right) \cdot \left(x + -1\right)\right)} \]
      8. metadata-eval99.5%

        \[\leadsto \frac{-2 \cdot \left(\left(-1 - x\right) \cdot \left(x + -1\right)\right) - x \cdot \left(x + \left(-1 - \left(-1 - x\right) \cdot \color{blue}{1}\right)\right)}{x \cdot \left(\left(-1 - x\right) \cdot \left(x + -1\right)\right)} \]
      9. *-rgt-identity99.5%

        \[\leadsto \frac{-2 \cdot \left(\left(-1 - x\right) \cdot \left(x + -1\right)\right) - x \cdot \left(x + \left(-1 - \color{blue}{\left(-1 - x\right)}\right)\right)}{x \cdot \left(\left(-1 - x\right) \cdot \left(x + -1\right)\right)} \]
    8. Applied egg-rr99.5%

      \[\leadsto \color{blue}{\frac{-2 \cdot \left(\left(-1 - x\right) \cdot \left(x + -1\right)\right) - x \cdot \left(x + \left(-1 - \left(-1 - x\right)\right)\right)}{x \cdot \left(\left(-1 - x\right) \cdot \left(x + -1\right)\right)}} \]
    9. Step-by-step derivation
      1. Simplified99.5%

        \[\leadsto \color{blue}{\frac{-2 \cdot \left(\left(1 - x\right) \cdot \left(1 + x\right)\right) - x \cdot \left(x + x\right)}{x \cdot \left(\left(1 - x\right) \cdot \left(1 + x\right)\right)}} \]
    10. Recombined 2 regimes into one program.
    11. Final simplification74.9%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x + -1} \leq 5 \cdot 10^{-25}:\\ \;\;\;\;\frac{\frac{\frac{1}{x}}{x + -1}}{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{-2 \cdot \left(\left(1 - x\right) \cdot \left(x + 1\right)\right) - x \cdot \left(x + x\right)}{x \cdot \left(\left(1 - x\right) \cdot \left(x + 1\right)\right)}\\ \end{array} \]
    12. Add Preprocessing

    Alternative 4: 68.8% accurate, 1.7× speedup?

    \[\begin{array}{l} \\ \frac{1}{x + -1} + \frac{-1}{x} \end{array} \]
    (FPCore (x) :precision binary64 (+ (/ 1.0 (+ x -1.0)) (/ -1.0 x)))
    double code(double x) {
    	return (1.0 / (x + -1.0)) + (-1.0 / x);
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        code = (1.0d0 / (x + (-1.0d0))) + ((-1.0d0) / x)
    end function
    
    public static double code(double x) {
    	return (1.0 / (x + -1.0)) + (-1.0 / x);
    }
    
    def code(x):
    	return (1.0 / (x + -1.0)) + (-1.0 / x)
    
    function code(x)
    	return Float64(Float64(1.0 / Float64(x + -1.0)) + Float64(-1.0 / x))
    end
    
    function tmp = code(x)
    	tmp = (1.0 / (x + -1.0)) + (-1.0 / x);
    end
    
    code[x_] := N[(N[(1.0 / N[(x + -1.0), $MachinePrecision]), $MachinePrecision] + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{1}{x + -1} + \frac{-1}{x}
    \end{array}
    
    Derivation
    1. Initial program 70.6%

      \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. +-commutative70.6%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
      2. associate-+r-70.5%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
      3. sub-neg70.5%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
      4. remove-double-neg70.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      5. neg-sub070.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      6. associate-+l-70.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      7. neg-sub070.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      8. distribute-neg-frac270.5%

        \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
      9. distribute-frac-neg270.5%

        \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
      10. associate-+r+70.6%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
      11. +-commutative70.6%

        \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
      12. remove-double-neg70.6%

        \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      13. distribute-neg-frac270.6%

        \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      14. sub0-neg70.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      15. associate-+l-70.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      16. neg-sub070.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    3. Simplified70.6%

      \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 69.3%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1}{x}} \]
    6. Final simplification69.3%

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

    Alternative 5: 73.0% accurate, 1.7× speedup?

    \[\begin{array}{l} \\ \frac{\frac{\frac{1}{x}}{x + -1}}{x} \end{array} \]
    (FPCore (x) :precision binary64 (/ (/ (/ 1.0 x) (+ x -1.0)) x))
    double code(double x) {
    	return ((1.0 / x) / (x + -1.0)) / x;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        code = ((1.0d0 / x) / (x + (-1.0d0))) / x
    end function
    
    public static double code(double x) {
    	return ((1.0 / x) / (x + -1.0)) / x;
    }
    
    def code(x):
    	return ((1.0 / x) / (x + -1.0)) / x
    
    function code(x)
    	return Float64(Float64(Float64(1.0 / x) / Float64(x + -1.0)) / x)
    end
    
    function tmp = code(x)
    	tmp = ((1.0 / x) / (x + -1.0)) / x;
    end
    
    code[x_] := N[(N[(N[(1.0 / x), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{\frac{\frac{1}{x}}{x + -1}}{x}
    \end{array}
    
    Derivation
    1. Initial program 70.6%

      \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. +-commutative70.6%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
      2. associate-+r-70.5%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
      3. sub-neg70.5%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
      4. remove-double-neg70.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      5. neg-sub070.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      6. associate-+l-70.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      7. neg-sub070.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      8. distribute-neg-frac270.5%

        \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
      9. distribute-frac-neg270.5%

        \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
      10. associate-+r+70.6%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
      11. +-commutative70.6%

        \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
      12. remove-double-neg70.6%

        \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      13. distribute-neg-frac270.6%

        \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      14. sub0-neg70.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      15. associate-+l-70.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      16. neg-sub070.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    3. Simplified70.6%

      \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 69.4%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{-1 \cdot \frac{1 + \frac{1}{x}}{x}} \]
    6. Step-by-step derivation
      1. associate-*r/69.4%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1 \cdot \left(1 + \frac{1}{x}\right)}{x}} \]
      2. neg-mul-169.4%

        \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{-\left(1 + \frac{1}{x}\right)}}{x} \]
      3. distribute-neg-in69.4%

        \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{\left(-1\right) + \left(-\frac{1}{x}\right)}}{x} \]
      4. metadata-eval69.4%

        \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{-1} + \left(-\frac{1}{x}\right)}{x} \]
      5. distribute-neg-frac69.4%

        \[\leadsto \frac{1}{x + -1} + \frac{-1 + \color{blue}{\frac{-1}{x}}}{x} \]
      6. metadata-eval69.4%

        \[\leadsto \frac{1}{x + -1} + \frac{-1 + \frac{\color{blue}{-1}}{x}}{x} \]
    7. Simplified69.4%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1 + \frac{-1}{x}}{x}} \]
    8. Step-by-step derivation
      1. frac-2neg69.4%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-\left(-1 + \frac{-1}{x}\right)}{-x}} \]
      2. div-inv69.5%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(-\left(-1 + \frac{-1}{x}\right)\right) \cdot \frac{1}{-x}} \]
      3. +-commutative69.5%

        \[\leadsto \frac{1}{x + -1} + \left(-\color{blue}{\left(\frac{-1}{x} + -1\right)}\right) \cdot \frac{1}{-x} \]
      4. add-sqr-sqrt34.3%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\color{blue}{\sqrt{\frac{-1}{x}} \cdot \sqrt{\frac{-1}{x}}} + -1\right)\right) \cdot \frac{1}{-x} \]
      5. sqrt-unprod69.5%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\color{blue}{\sqrt{\frac{-1}{x} \cdot \frac{-1}{x}}} + -1\right)\right) \cdot \frac{1}{-x} \]
      6. frac-times69.5%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\sqrt{\color{blue}{\frac{-1 \cdot -1}{x \cdot x}}} + -1\right)\right) \cdot \frac{1}{-x} \]
      7. metadata-eval69.5%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\sqrt{\frac{\color{blue}{1}}{x \cdot x}} + -1\right)\right) \cdot \frac{1}{-x} \]
      8. metadata-eval69.5%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\sqrt{\frac{\color{blue}{1 \cdot 1}}{x \cdot x}} + -1\right)\right) \cdot \frac{1}{-x} \]
      9. frac-times69.5%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\sqrt{\color{blue}{\frac{1}{x} \cdot \frac{1}{x}}} + -1\right)\right) \cdot \frac{1}{-x} \]
      10. sqrt-prod35.2%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\color{blue}{\sqrt{\frac{1}{x}} \cdot \sqrt{\frac{1}{x}}} + -1\right)\right) \cdot \frac{1}{-x} \]
      11. add-sqr-sqrt69.3%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\color{blue}{\frac{1}{x}} + -1\right)\right) \cdot \frac{1}{-x} \]
      12. metadata-eval69.3%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \frac{\color{blue}{--1}}{-x} \]
      13. frac-2neg69.3%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \color{blue}{\frac{-1}{x}} \]
      14. add-sqr-sqrt17.2%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \color{blue}{\left(\sqrt{\frac{-1}{x}} \cdot \sqrt{\frac{-1}{x}}\right)} \]
      15. sqrt-unprod16.1%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \color{blue}{\sqrt{\frac{-1}{x} \cdot \frac{-1}{x}}} \]
      16. frac-times13.1%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \sqrt{\color{blue}{\frac{-1 \cdot -1}{x \cdot x}}} \]
      17. metadata-eval13.1%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \sqrt{\frac{\color{blue}{1}}{x \cdot x}} \]
      18. metadata-eval13.1%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \sqrt{\frac{\color{blue}{1 \cdot 1}}{x \cdot x}} \]
      19. frac-times16.1%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \sqrt{\color{blue}{\frac{1}{x} \cdot \frac{1}{x}}} \]
      20. sqrt-prod3.4%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \color{blue}{\left(\sqrt{\frac{1}{x}} \cdot \sqrt{\frac{1}{x}}\right)} \]
      21. add-sqr-sqrt6.5%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \color{blue}{\frac{1}{x}} \]
    9. Applied egg-rr6.5%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(-\left(\frac{1}{x} + -1\right)\right) \cdot \frac{1}{x}} \]
    10. Step-by-step derivation
      1. add-sqr-sqrt6.5%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(\sqrt{-\left(\frac{1}{x} + -1\right)} \cdot \sqrt{-\left(\frac{1}{x} + -1\right)}\right)} \cdot \frac{1}{x} \]
      2. sqrt-unprod6.5%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\sqrt{\left(-\left(\frac{1}{x} + -1\right)\right) \cdot \left(-\left(\frac{1}{x} + -1\right)\right)}} \cdot \frac{1}{x} \]
      3. sqr-neg6.5%

        \[\leadsto \frac{1}{x + -1} + \sqrt{\color{blue}{\left(\frac{1}{x} + -1\right) \cdot \left(\frac{1}{x} + -1\right)}} \cdot \frac{1}{x} \]
      4. sqrt-unprod0.0%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(\sqrt{\frac{1}{x} + -1} \cdot \sqrt{\frac{1}{x} + -1}\right)} \cdot \frac{1}{x} \]
      5. add-sqr-sqrt69.3%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(\frac{1}{x} + -1\right)} \cdot \frac{1}{x} \]
      6. cancel-sign-sub69.3%

        \[\leadsto \color{blue}{\frac{1}{x + -1} - \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \frac{1}{x}} \]
      7. un-div-inv69.3%

        \[\leadsto \frac{1}{x + -1} - \color{blue}{\frac{-\left(\frac{1}{x} + -1\right)}{x}} \]
      8. frac-sub69.3%

        \[\leadsto \color{blue}{\frac{1 \cdot x - \left(x + -1\right) \cdot \left(-\left(\frac{1}{x} + -1\right)\right)}{\left(x + -1\right) \cdot x}} \]
    11. Applied egg-rr69.5%

      \[\leadsto \color{blue}{\frac{x - \left(x + -1\right) \cdot \left(1 + \frac{1}{x}\right)}{\left(x + -1\right) \cdot x}} \]
    12. Step-by-step derivation
      1. associate-/r*69.5%

        \[\leadsto \color{blue}{\frac{\frac{x - \left(x + -1\right) \cdot \left(1 + \frac{1}{x}\right)}{x + -1}}{x}} \]
    13. Simplified73.4%

      \[\leadsto \color{blue}{\frac{\frac{\frac{1}{x}}{x + -1}}{x}} \]
    14. Final simplification73.4%

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

    Alternative 6: 68.5% accurate, 2.1× speedup?

    \[\begin{array}{l} \\ -1 + \left(1 + \frac{-2}{x}\right) \end{array} \]
    (FPCore (x) :precision binary64 (+ -1.0 (+ 1.0 (/ -2.0 x))))
    double code(double x) {
    	return -1.0 + (1.0 + (-2.0 / x));
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        code = (-1.0d0) + (1.0d0 + ((-2.0d0) / x))
    end function
    
    public static double code(double x) {
    	return -1.0 + (1.0 + (-2.0 / x));
    }
    
    def code(x):
    	return -1.0 + (1.0 + (-2.0 / x))
    
    function code(x)
    	return Float64(-1.0 + Float64(1.0 + Float64(-2.0 / x)))
    end
    
    function tmp = code(x)
    	tmp = -1.0 + (1.0 + (-2.0 / x));
    end
    
    code[x_] := N[(-1.0 + N[(1.0 + N[(-2.0 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    -1 + \left(1 + \frac{-2}{x}\right)
    \end{array}
    
    Derivation
    1. Initial program 70.6%

      \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. +-commutative70.6%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
      2. associate-+r-70.5%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
      3. sub-neg70.5%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
      4. remove-double-neg70.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      5. neg-sub070.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      6. associate-+l-70.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      7. neg-sub070.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      8. distribute-neg-frac270.5%

        \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
      9. distribute-frac-neg270.5%

        \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
      10. associate-+r+70.6%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
      11. +-commutative70.6%

        \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
      12. remove-double-neg70.6%

        \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      13. distribute-neg-frac270.6%

        \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      14. sub0-neg70.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      15. associate-+l-70.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      16. neg-sub070.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    3. Simplified70.6%

      \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 3.5%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{x - 2}{x}} \]
    6. Step-by-step derivation
      1. div-sub3.5%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(\frac{x}{x} - \frac{2}{x}\right)} \]
      2. sub-neg3.5%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(\frac{x}{x} + \left(-\frac{2}{x}\right)\right)} \]
      3. *-inverses3.5%

        \[\leadsto \frac{1}{x + -1} + \left(\color{blue}{1} + \left(-\frac{2}{x}\right)\right) \]
      4. metadata-eval3.5%

        \[\leadsto \frac{1}{x + -1} + \left(1 + \left(-\frac{\color{blue}{--2}}{x}\right)\right) \]
      5. distribute-neg-frac3.5%

        \[\leadsto \frac{1}{x + -1} + \left(1 + \left(-\color{blue}{\left(-\frac{-2}{x}\right)}\right)\right) \]
      6. remove-double-neg3.5%

        \[\leadsto \frac{1}{x + -1} + \left(1 + \color{blue}{\frac{-2}{x}}\right) \]
    7. Simplified3.5%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(1 + \frac{-2}{x}\right)} \]
    8. Taylor expanded in x around 0 68.9%

      \[\leadsto \color{blue}{-1} + \left(1 + \frac{-2}{x}\right) \]
    9. Final simplification68.9%

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

    Alternative 7: 68.6% accurate, 2.1× speedup?

    \[\begin{array}{l} \\ \frac{-2}{x} - \frac{-2}{x} \end{array} \]
    (FPCore (x) :precision binary64 (- (/ -2.0 x) (/ -2.0 x)))
    double code(double x) {
    	return (-2.0 / x) - (-2.0 / x);
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        code = ((-2.0d0) / x) - ((-2.0d0) / x)
    end function
    
    public static double code(double x) {
    	return (-2.0 / x) - (-2.0 / x);
    }
    
    def code(x):
    	return (-2.0 / x) - (-2.0 / x)
    
    function code(x)
    	return Float64(Float64(-2.0 / x) - Float64(-2.0 / x))
    end
    
    function tmp = code(x)
    	tmp = (-2.0 / x) - (-2.0 / x);
    end
    
    code[x_] := N[(N[(-2.0 / x), $MachinePrecision] - N[(-2.0 / x), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{-2}{x} - \frac{-2}{x}
    \end{array}
    
    Derivation
    1. Initial program 70.6%

      \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. +-commutative70.6%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
      2. associate-+r-70.5%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
      3. sub-neg70.5%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
      4. remove-double-neg70.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      5. neg-sub070.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      6. associate-+l-70.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      7. neg-sub070.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      8. distribute-neg-frac270.5%

        \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
      9. distribute-frac-neg270.5%

        \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
      10. associate-+r+70.6%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
      11. +-commutative70.6%

        \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
      12. remove-double-neg70.6%

        \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      13. distribute-neg-frac270.6%

        \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      14. sub0-neg70.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      15. associate-+l-70.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      16. neg-sub070.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    3. Simplified70.6%

      \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. +-commutative70.6%

        \[\leadsto \color{blue}{\left(\frac{-2}{x} - \frac{1}{-1 - x}\right) + \frac{1}{x + -1}} \]
      2. associate-+l-70.5%

        \[\leadsto \color{blue}{\frac{-2}{x} - \left(\frac{1}{-1 - x} - \frac{1}{x + -1}\right)} \]
    6. Applied egg-rr70.5%

      \[\leadsto \color{blue}{\frac{-2}{x} - \left(\frac{1}{-1 - x} - \frac{1}{x + -1}\right)} \]
    7. Step-by-step derivation
      1. frac-sub19.0%

        \[\leadsto \frac{-2}{x} - \color{blue}{\frac{1 \cdot \left(x + -1\right) - \left(-1 - x\right) \cdot 1}{\left(-1 - x\right) \cdot \left(x + -1\right)}} \]
      2. div-inv19.8%

        \[\leadsto \frac{-2}{x} - \color{blue}{\left(1 \cdot \left(x + -1\right) - \left(-1 - x\right) \cdot 1\right) \cdot \frac{1}{\left(-1 - x\right) \cdot \left(x + -1\right)}} \]
      3. *-un-lft-identity19.8%

        \[\leadsto \frac{-2}{x} - \left(\color{blue}{\left(x + -1\right)} - \left(-1 - x\right) \cdot 1\right) \cdot \frac{1}{\left(-1 - x\right) \cdot \left(x + -1\right)} \]
      4. metadata-eval19.8%

        \[\leadsto \frac{-2}{x} - \left(\left(x + -1\right) - \left(-1 - x\right) \cdot \color{blue}{\frac{1}{1}}\right) \cdot \frac{1}{\left(-1 - x\right) \cdot \left(x + -1\right)} \]
      5. div-inv19.8%

        \[\leadsto \frac{-2}{x} - \left(\left(x + -1\right) - \color{blue}{\frac{-1 - x}{1}}\right) \cdot \frac{1}{\left(-1 - x\right) \cdot \left(x + -1\right)} \]
      6. associate--l+19.7%

        \[\leadsto \frac{-2}{x} - \color{blue}{\left(x + \left(-1 - \frac{-1 - x}{1}\right)\right)} \cdot \frac{1}{\left(-1 - x\right) \cdot \left(x + -1\right)} \]
      7. div-inv19.7%

        \[\leadsto \frac{-2}{x} - \left(x + \left(-1 - \color{blue}{\left(-1 - x\right) \cdot \frac{1}{1}}\right)\right) \cdot \frac{1}{\left(-1 - x\right) \cdot \left(x + -1\right)} \]
      8. metadata-eval19.7%

        \[\leadsto \frac{-2}{x} - \left(x + \left(-1 - \left(-1 - x\right) \cdot \color{blue}{1}\right)\right) \cdot \frac{1}{\left(-1 - x\right) \cdot \left(x + -1\right)} \]
      9. *-rgt-identity19.7%

        \[\leadsto \frac{-2}{x} - \left(x + \left(-1 - \color{blue}{\left(-1 - x\right)}\right)\right) \cdot \frac{1}{\left(-1 - x\right) \cdot \left(x + -1\right)} \]
    8. Applied egg-rr19.7%

      \[\leadsto \frac{-2}{x} - \color{blue}{\left(x + \left(-1 - \left(-1 - x\right)\right)\right) \cdot \frac{1}{\left(-1 - x\right) \cdot \left(x + -1\right)}} \]
    9. Step-by-step derivation
      1. associate--r-19.8%

        \[\leadsto \frac{-2}{x} - \left(x + \color{blue}{\left(\left(-1 - -1\right) + x\right)}\right) \cdot \frac{1}{\left(-1 - x\right) \cdot \left(x + -1\right)} \]
      2. metadata-eval19.8%

        \[\leadsto \frac{-2}{x} - \left(x + \left(\color{blue}{0} + x\right)\right) \cdot \frac{1}{\left(-1 - x\right) \cdot \left(x + -1\right)} \]
      3. *-commutative19.8%

        \[\leadsto \frac{-2}{x} - \left(x + \left(0 + x\right)\right) \cdot \frac{1}{\color{blue}{\left(x + -1\right) \cdot \left(-1 - x\right)}} \]
    10. Simplified19.8%

      \[\leadsto \frac{-2}{x} - \color{blue}{\left(x + \left(0 + x\right)\right) \cdot \frac{1}{\left(x + -1\right) \cdot \left(-1 - x\right)}} \]
    11. Taylor expanded in x around inf 69.0%

      \[\leadsto \frac{-2}{x} - \color{blue}{\frac{-2}{x}} \]
    12. Final simplification69.0%

      \[\leadsto \frac{-2}{x} - \frac{-2}{x} \]
    13. Add Preprocessing

    Alternative 8: 5.1% accurate, 5.0× speedup?

    \[\begin{array}{l} \\ \frac{-2}{x} \end{array} \]
    (FPCore (x) :precision binary64 (/ -2.0 x))
    double code(double x) {
    	return -2.0 / x;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        code = (-2.0d0) / x
    end function
    
    public static double code(double x) {
    	return -2.0 / x;
    }
    
    def code(x):
    	return -2.0 / x
    
    function code(x)
    	return Float64(-2.0 / x)
    end
    
    function tmp = code(x)
    	tmp = -2.0 / x;
    end
    
    code[x_] := N[(-2.0 / x), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{-2}{x}
    \end{array}
    
    Derivation
    1. Initial program 70.6%

      \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. +-commutative70.6%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
      2. associate-+r-70.5%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
      3. sub-neg70.5%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
      4. remove-double-neg70.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      5. neg-sub070.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      6. associate-+l-70.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      7. neg-sub070.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      8. distribute-neg-frac270.5%

        \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
      9. distribute-frac-neg270.5%

        \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
      10. associate-+r+70.6%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
      11. +-commutative70.6%

        \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
      12. remove-double-neg70.6%

        \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      13. distribute-neg-frac270.6%

        \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      14. sub0-neg70.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      15. associate-+l-70.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      16. neg-sub070.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    3. Simplified70.6%

      \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 5.1%

      \[\leadsto \color{blue}{\frac{-2}{x}} \]
    6. Final simplification5.1%

      \[\leadsto \frac{-2}{x} \]
    7. Add Preprocessing

    Alternative 9: 5.1% accurate, 5.0× speedup?

    \[\begin{array}{l} \\ \frac{-1}{x} \end{array} \]
    (FPCore (x) :precision binary64 (/ -1.0 x))
    double code(double x) {
    	return -1.0 / x;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        code = (-1.0d0) / x
    end function
    
    public static double code(double x) {
    	return -1.0 / x;
    }
    
    def code(x):
    	return -1.0 / x
    
    function code(x)
    	return Float64(-1.0 / x)
    end
    
    function tmp = code(x)
    	tmp = -1.0 / x;
    end
    
    code[x_] := N[(-1.0 / x), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{-1}{x}
    \end{array}
    
    Derivation
    1. Initial program 70.6%

      \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. +-commutative70.6%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
      2. associate-+r-70.5%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
      3. sub-neg70.5%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
      4. remove-double-neg70.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      5. neg-sub070.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      6. associate-+l-70.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      7. neg-sub070.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      8. distribute-neg-frac270.5%

        \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
      9. distribute-frac-neg270.5%

        \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
      10. associate-+r+70.6%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
      11. +-commutative70.6%

        \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
      12. remove-double-neg70.6%

        \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      13. distribute-neg-frac270.6%

        \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      14. sub0-neg70.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      15. associate-+l-70.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      16. neg-sub070.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    3. Simplified70.6%

      \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 3.5%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{x - 2}{x}} \]
    6. Step-by-step derivation
      1. div-sub3.5%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(\frac{x}{x} - \frac{2}{x}\right)} \]
      2. sub-neg3.5%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(\frac{x}{x} + \left(-\frac{2}{x}\right)\right)} \]
      3. *-inverses3.5%

        \[\leadsto \frac{1}{x + -1} + \left(\color{blue}{1} + \left(-\frac{2}{x}\right)\right) \]
      4. metadata-eval3.5%

        \[\leadsto \frac{1}{x + -1} + \left(1 + \left(-\frac{\color{blue}{--2}}{x}\right)\right) \]
      5. distribute-neg-frac3.5%

        \[\leadsto \frac{1}{x + -1} + \left(1 + \left(-\color{blue}{\left(-\frac{-2}{x}\right)}\right)\right) \]
      6. remove-double-neg3.5%

        \[\leadsto \frac{1}{x + -1} + \left(1 + \color{blue}{\frac{-2}{x}}\right) \]
    7. Simplified3.5%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(1 + \frac{-2}{x}\right)} \]
    8. Taylor expanded in x around inf 3.5%

      \[\leadsto \color{blue}{\frac{1}{x}} + \left(1 + \frac{-2}{x}\right) \]
    9. Taylor expanded in x around 0 5.2%

      \[\leadsto \color{blue}{\frac{-1}{x}} \]
    10. Final simplification5.2%

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

    Alternative 10: 6.3% accurate, 5.0× speedup?

    \[\begin{array}{l} \\ \frac{2}{x} \end{array} \]
    (FPCore (x) :precision binary64 (/ 2.0 x))
    double code(double x) {
    	return 2.0 / x;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        code = 2.0d0 / x
    end function
    
    public static double code(double x) {
    	return 2.0 / x;
    }
    
    def code(x):
    	return 2.0 / x
    
    function code(x)
    	return Float64(2.0 / x)
    end
    
    function tmp = code(x)
    	tmp = 2.0 / x;
    end
    
    code[x_] := N[(2.0 / x), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{2}{x}
    \end{array}
    
    Derivation
    1. Initial program 70.6%

      \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. +-commutative70.6%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
      2. associate-+r-70.5%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
      3. sub-neg70.5%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
      4. remove-double-neg70.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      5. neg-sub070.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      6. associate-+l-70.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      7. neg-sub070.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      8. distribute-neg-frac270.5%

        \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
      9. distribute-frac-neg270.5%

        \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
      10. associate-+r+70.6%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
      11. +-commutative70.6%

        \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
      12. remove-double-neg70.6%

        \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      13. distribute-neg-frac270.6%

        \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      14. sub0-neg70.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      15. associate-+l-70.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      16. neg-sub070.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    3. Simplified70.6%

      \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 69.4%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{-1 \cdot \frac{1 + \frac{1}{x}}{x}} \]
    6. Step-by-step derivation
      1. associate-*r/69.4%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1 \cdot \left(1 + \frac{1}{x}\right)}{x}} \]
      2. neg-mul-169.4%

        \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{-\left(1 + \frac{1}{x}\right)}}{x} \]
      3. distribute-neg-in69.4%

        \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{\left(-1\right) + \left(-\frac{1}{x}\right)}}{x} \]
      4. metadata-eval69.4%

        \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{-1} + \left(-\frac{1}{x}\right)}{x} \]
      5. distribute-neg-frac69.4%

        \[\leadsto \frac{1}{x + -1} + \frac{-1 + \color{blue}{\frac{-1}{x}}}{x} \]
      6. metadata-eval69.4%

        \[\leadsto \frac{1}{x + -1} + \frac{-1 + \frac{\color{blue}{-1}}{x}}{x} \]
    7. Simplified69.4%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1 + \frac{-1}{x}}{x}} \]
    8. Step-by-step derivation
      1. frac-2neg69.4%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-\left(-1 + \frac{-1}{x}\right)}{-x}} \]
      2. div-inv69.5%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(-\left(-1 + \frac{-1}{x}\right)\right) \cdot \frac{1}{-x}} \]
      3. +-commutative69.5%

        \[\leadsto \frac{1}{x + -1} + \left(-\color{blue}{\left(\frac{-1}{x} + -1\right)}\right) \cdot \frac{1}{-x} \]
      4. add-sqr-sqrt34.3%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\color{blue}{\sqrt{\frac{-1}{x}} \cdot \sqrt{\frac{-1}{x}}} + -1\right)\right) \cdot \frac{1}{-x} \]
      5. sqrt-unprod69.5%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\color{blue}{\sqrt{\frac{-1}{x} \cdot \frac{-1}{x}}} + -1\right)\right) \cdot \frac{1}{-x} \]
      6. frac-times69.5%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\sqrt{\color{blue}{\frac{-1 \cdot -1}{x \cdot x}}} + -1\right)\right) \cdot \frac{1}{-x} \]
      7. metadata-eval69.5%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\sqrt{\frac{\color{blue}{1}}{x \cdot x}} + -1\right)\right) \cdot \frac{1}{-x} \]
      8. metadata-eval69.5%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\sqrt{\frac{\color{blue}{1 \cdot 1}}{x \cdot x}} + -1\right)\right) \cdot \frac{1}{-x} \]
      9. frac-times69.5%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\sqrt{\color{blue}{\frac{1}{x} \cdot \frac{1}{x}}} + -1\right)\right) \cdot \frac{1}{-x} \]
      10. sqrt-prod35.2%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\color{blue}{\sqrt{\frac{1}{x}} \cdot \sqrt{\frac{1}{x}}} + -1\right)\right) \cdot \frac{1}{-x} \]
      11. add-sqr-sqrt69.3%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\color{blue}{\frac{1}{x}} + -1\right)\right) \cdot \frac{1}{-x} \]
      12. metadata-eval69.3%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \frac{\color{blue}{--1}}{-x} \]
      13. frac-2neg69.3%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \color{blue}{\frac{-1}{x}} \]
      14. add-sqr-sqrt17.2%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \color{blue}{\left(\sqrt{\frac{-1}{x}} \cdot \sqrt{\frac{-1}{x}}\right)} \]
      15. sqrt-unprod16.1%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \color{blue}{\sqrt{\frac{-1}{x} \cdot \frac{-1}{x}}} \]
      16. frac-times13.1%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \sqrt{\color{blue}{\frac{-1 \cdot -1}{x \cdot x}}} \]
      17. metadata-eval13.1%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \sqrt{\frac{\color{blue}{1}}{x \cdot x}} \]
      18. metadata-eval13.1%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \sqrt{\frac{\color{blue}{1 \cdot 1}}{x \cdot x}} \]
      19. frac-times16.1%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \sqrt{\color{blue}{\frac{1}{x} \cdot \frac{1}{x}}} \]
      20. sqrt-prod3.4%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \color{blue}{\left(\sqrt{\frac{1}{x}} \cdot \sqrt{\frac{1}{x}}\right)} \]
      21. add-sqr-sqrt6.5%

        \[\leadsto \frac{1}{x + -1} + \left(-\left(\frac{1}{x} + -1\right)\right) \cdot \color{blue}{\frac{1}{x}} \]
    9. Applied egg-rr6.5%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(-\left(\frac{1}{x} + -1\right)\right) \cdot \frac{1}{x}} \]
    10. Taylor expanded in x around inf 6.5%

      \[\leadsto \color{blue}{\frac{2}{x}} \]
    11. Final simplification6.5%

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

    Alternative 11: 3.4% accurate, 15.0× speedup?

    \[\begin{array}{l} \\ 1 \end{array} \]
    (FPCore (x) :precision binary64 1.0)
    double code(double x) {
    	return 1.0;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        code = 1.0d0
    end function
    
    public static double code(double x) {
    	return 1.0;
    }
    
    def code(x):
    	return 1.0
    
    function code(x)
    	return 1.0
    end
    
    function tmp = code(x)
    	tmp = 1.0;
    end
    
    code[x_] := 1.0
    
    \begin{array}{l}
    
    \\
    1
    \end{array}
    
    Derivation
    1. Initial program 70.6%

      \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
    2. Step-by-step derivation
      1. +-commutative70.6%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
      2. associate-+r-70.5%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
      3. sub-neg70.5%

        \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
      4. remove-double-neg70.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      5. neg-sub070.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
      6. associate-+l-70.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      7. neg-sub070.5%

        \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
      8. distribute-neg-frac270.5%

        \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
      9. distribute-frac-neg270.5%

        \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
      10. associate-+r+70.6%

        \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
      11. +-commutative70.6%

        \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
      12. remove-double-neg70.6%

        \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      13. distribute-neg-frac270.6%

        \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      14. sub0-neg70.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      15. associate-+l-70.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
      16. neg-sub070.6%

        \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    3. Simplified70.6%

      \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 3.5%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{x - 2}{x}} \]
    6. Step-by-step derivation
      1. div-sub3.5%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(\frac{x}{x} - \frac{2}{x}\right)} \]
      2. sub-neg3.5%

        \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(\frac{x}{x} + \left(-\frac{2}{x}\right)\right)} \]
      3. *-inverses3.5%

        \[\leadsto \frac{1}{x + -1} + \left(\color{blue}{1} + \left(-\frac{2}{x}\right)\right) \]
      4. metadata-eval3.5%

        \[\leadsto \frac{1}{x + -1} + \left(1 + \left(-\frac{\color{blue}{--2}}{x}\right)\right) \]
      5. distribute-neg-frac3.5%

        \[\leadsto \frac{1}{x + -1} + \left(1 + \left(-\color{blue}{\left(-\frac{-2}{x}\right)}\right)\right) \]
      6. remove-double-neg3.5%

        \[\leadsto \frac{1}{x + -1} + \left(1 + \color{blue}{\frac{-2}{x}}\right) \]
    7. Simplified3.5%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{\left(1 + \frac{-2}{x}\right)} \]
    8. Taylor expanded in x around inf 3.5%

      \[\leadsto \color{blue}{1} \]
    9. Final simplification3.5%

      \[\leadsto 1 \]
    10. Add Preprocessing

    Developer target: 99.3% accurate, 1.7× speedup?

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

    Reproduce

    ?
    herbie shell --seed 2024079 
    (FPCore (x)
      :name "3frac (problem 3.3.3)"
      :precision binary64
      :pre (> (fabs x) 1.0)
    
      :alt
      (/ 2.0 (* x (- (* x x) 1.0)))
    
      (+ (- (/ 1.0 (+ x 1.0)) (/ 2.0 x)) (/ 1.0 (- x 1.0))))