3frac (problem 3.3.3)

Percentage Accurate: 70.4% → 99.8%
Time: 11.3s
Alternatives: 11
Speedup: 1.0×

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: 70.4% 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: 99.8% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \frac{2}{x} \cdot \frac{1}{\mathsf{fma}\left(x, x, -1\right)} \end{array} \]
(FPCore (x) :precision binary64 (* (/ 2.0 x) (/ 1.0 (fma x x -1.0))))
double code(double x) {
	return (2.0 / x) * (1.0 / fma(x, x, -1.0));
}
function code(x)
	return Float64(Float64(2.0 / x) * Float64(1.0 / fma(x, x, -1.0)))
end
code[x_] := N[(N[(2.0 / x), $MachinePrecision] * N[(1.0 / N[(x * x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{2}{x} \cdot \frac{1}{\mathsf{fma}\left(x, x, -1\right)}
\end{array}
Derivation
  1. Initial program 67.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative67.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg67.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac267.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub067.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified67.0%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. frac-2neg67.0%

      \[\leadsto \color{blue}{\frac{-1}{-\left(x + -1\right)}} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right) \]
    2. metadata-eval67.0%

      \[\leadsto \frac{\color{blue}{-1}}{-\left(x + -1\right)} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right) \]
    3. frac-sub16.0%

      \[\leadsto \frac{-1}{-\left(x + -1\right)} + \color{blue}{\frac{-2 \cdot \left(-1 - x\right) - x \cdot 1}{x \cdot \left(-1 - x\right)}} \]
    4. frac-add16.8%

      \[\leadsto \color{blue}{\frac{-1 \cdot \left(x \cdot \left(-1 - x\right)\right) + \left(-\left(x + -1\right)\right) \cdot \left(-2 \cdot \left(-1 - x\right) - x \cdot 1\right)}{\left(-\left(x + -1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)}} \]
    5. fma-define16.8%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \left(-\left(x + -1\right)\right) \cdot \left(-2 \cdot \left(-1 - x\right) - x \cdot 1\right)\right)}}{\left(-\left(x + -1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    6. distribute-neg-in16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \color{blue}{\left(\left(-x\right) + \left(--1\right)\right)} \cdot \left(-2 \cdot \left(-1 - x\right) - x \cdot 1\right)\right)}{\left(-\left(x + -1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    7. neg-mul-116.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \left(\color{blue}{-1 \cdot x} + \left(--1\right)\right) \cdot \left(-2 \cdot \left(-1 - x\right) - x \cdot 1\right)\right)}{\left(-\left(x + -1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    8. *-commutative16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \left(\color{blue}{x \cdot -1} + \left(--1\right)\right) \cdot \left(-2 \cdot \left(-1 - x\right) - x \cdot 1\right)\right)}{\left(-\left(x + -1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    9. metadata-eval16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \left(x \cdot -1 + \color{blue}{1}\right) \cdot \left(-2 \cdot \left(-1 - x\right) - x \cdot 1\right)\right)}{\left(-\left(x + -1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    10. fma-define16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \color{blue}{\mathsf{fma}\left(x, -1, 1\right)} \cdot \left(-2 \cdot \left(-1 - x\right) - x \cdot 1\right)\right)}{\left(-\left(x + -1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    11. *-rgt-identity16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \left(-2 \cdot \left(-1 - x\right) - \color{blue}{x}\right)\right)}{\left(-\left(x + -1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    12. fma-neg16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \color{blue}{\mathsf{fma}\left(-2, -1 - x, -x\right)}\right)}{\left(-\left(x + -1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    13. distribute-neg-in16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\color{blue}{\left(\left(-x\right) + \left(--1\right)\right)} \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    14. neg-mul-116.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\left(\color{blue}{-1 \cdot x} + \left(--1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    15. *-commutative16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\left(\color{blue}{x \cdot -1} + \left(--1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    16. metadata-eval16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\left(x \cdot -1 + \color{blue}{1}\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    17. fma-define16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\color{blue}{\mathsf{fma}\left(x, -1, 1\right)} \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
  6. Applied egg-rr16.8%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)}} \]
  7. Step-by-step derivation
    1. fma-undefine16.8%

      \[\leadsto \frac{\color{blue}{-1 \cdot \left(x \cdot \left(-1 - x\right)\right) + \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)}}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    2. neg-mul-116.8%

      \[\leadsto \frac{\color{blue}{\left(-x \cdot \left(-1 - x\right)\right)} + \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    3. distribute-rgt-neg-in16.8%

      \[\leadsto \frac{\color{blue}{x \cdot \left(-\left(-1 - x\right)\right)} + \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    4. fma-define15.2%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, -\left(-1 - x\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    5. sub-neg15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, -\color{blue}{\left(-1 + \left(-x\right)\right)}, \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    6. distribute-neg-in15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, \color{blue}{\left(--1\right) + \left(-\left(-x\right)\right)}, \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    7. metadata-eval15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, \color{blue}{1} + \left(-\left(-x\right)\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    8. remove-double-neg15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, 1 + \color{blue}{x}, \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    9. +-commutative15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, \color{blue}{x + 1}, \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    10. *-commutative15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \color{blue}{\mathsf{fma}\left(-2, -1 - x, -x\right) \cdot \mathsf{fma}\left(x, -1, 1\right)}\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    11. fma-neg15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \color{blue}{\left(-2 \cdot \left(-1 - x\right) - x\right)} \cdot \mathsf{fma}\left(x, -1, 1\right)\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    12. fma-undefine15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \left(-2 \cdot \left(-1 - x\right) - x\right) \cdot \color{blue}{\left(x \cdot -1 + 1\right)}\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    13. *-commutative15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \left(-2 \cdot \left(-1 - x\right) - x\right) \cdot \left(\color{blue}{-1 \cdot x} + 1\right)\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    14. neg-mul-115.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \left(-2 \cdot \left(-1 - x\right) - x\right) \cdot \left(\color{blue}{\left(-x\right)} + 1\right)\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    15. +-commutative15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \left(-2 \cdot \left(-1 - x\right) - x\right) \cdot \color{blue}{\left(1 + \left(-x\right)\right)}\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    16. unsub-neg15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \left(-2 \cdot \left(-1 - x\right) - x\right) \cdot \color{blue}{\left(1 - x\right)}\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    17. *-commutative15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \left(-2 \cdot \left(-1 - x\right) - x\right) \cdot \left(1 - x\right)\right)}{\color{blue}{\left(x \cdot \left(-1 - x\right)\right) \cdot \mathsf{fma}\left(x, -1, 1\right)}} \]
    18. associate-*l*15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \left(-2 \cdot \left(-1 - x\right) - x\right) \cdot \left(1 - x\right)\right)}{\color{blue}{x \cdot \left(\left(-1 - x\right) \cdot \mathsf{fma}\left(x, -1, 1\right)\right)}} \]
    19. *-commutative15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \left(-2 \cdot \left(-1 - x\right) - x\right) \cdot \left(1 - x\right)\right)}{x \cdot \color{blue}{\left(\mathsf{fma}\left(x, -1, 1\right) \cdot \left(-1 - x\right)\right)}} \]
  8. Simplified15.2%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x, x + 1, \left(-2 \cdot \left(-1 - x\right) - x\right) \cdot \left(1 - x\right)\right)}{x \cdot \mathsf{fma}\left(x, x, -1\right)}} \]
  9. Taylor expanded in x around 0 99.7%

    \[\leadsto \frac{\color{blue}{2}}{x \cdot \mathsf{fma}\left(x, x, -1\right)} \]
  10. Step-by-step derivation
    1. associate-/r*99.8%

      \[\leadsto \color{blue}{\frac{\frac{2}{x}}{\mathsf{fma}\left(x, x, -1\right)}} \]
    2. div-inv99.8%

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

    \[\leadsto \color{blue}{\frac{2}{x} \cdot \frac{1}{\mathsf{fma}\left(x, x, -1\right)}} \]
  12. Final simplification99.8%

    \[\leadsto \frac{2}{x} \cdot \frac{1}{\mathsf{fma}\left(x, x, -1\right)} \]
  13. Add Preprocessing

Alternative 2: 99.2% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \frac{2}{x \cdot \mathsf{fma}\left(x, x, -1\right)} \end{array} \]
(FPCore (x) :precision binary64 (/ 2.0 (* x (fma x x -1.0))))
double code(double x) {
	return 2.0 / (x * fma(x, x, -1.0));
}
function code(x)
	return Float64(2.0 / Float64(x * fma(x, x, -1.0)))
end
code[x_] := N[(2.0 / N[(x * N[(x * x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{2}{x \cdot \mathsf{fma}\left(x, x, -1\right)}
\end{array}
Derivation
  1. Initial program 67.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative67.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg67.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac267.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub067.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified67.0%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. frac-2neg67.0%

      \[\leadsto \color{blue}{\frac{-1}{-\left(x + -1\right)}} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right) \]
    2. metadata-eval67.0%

      \[\leadsto \frac{\color{blue}{-1}}{-\left(x + -1\right)} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right) \]
    3. frac-sub16.0%

      \[\leadsto \frac{-1}{-\left(x + -1\right)} + \color{blue}{\frac{-2 \cdot \left(-1 - x\right) - x \cdot 1}{x \cdot \left(-1 - x\right)}} \]
    4. frac-add16.8%

      \[\leadsto \color{blue}{\frac{-1 \cdot \left(x \cdot \left(-1 - x\right)\right) + \left(-\left(x + -1\right)\right) \cdot \left(-2 \cdot \left(-1 - x\right) - x \cdot 1\right)}{\left(-\left(x + -1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)}} \]
    5. fma-define16.8%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \left(-\left(x + -1\right)\right) \cdot \left(-2 \cdot \left(-1 - x\right) - x \cdot 1\right)\right)}}{\left(-\left(x + -1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    6. distribute-neg-in16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \color{blue}{\left(\left(-x\right) + \left(--1\right)\right)} \cdot \left(-2 \cdot \left(-1 - x\right) - x \cdot 1\right)\right)}{\left(-\left(x + -1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    7. neg-mul-116.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \left(\color{blue}{-1 \cdot x} + \left(--1\right)\right) \cdot \left(-2 \cdot \left(-1 - x\right) - x \cdot 1\right)\right)}{\left(-\left(x + -1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    8. *-commutative16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \left(\color{blue}{x \cdot -1} + \left(--1\right)\right) \cdot \left(-2 \cdot \left(-1 - x\right) - x \cdot 1\right)\right)}{\left(-\left(x + -1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    9. metadata-eval16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \left(x \cdot -1 + \color{blue}{1}\right) \cdot \left(-2 \cdot \left(-1 - x\right) - x \cdot 1\right)\right)}{\left(-\left(x + -1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    10. fma-define16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \color{blue}{\mathsf{fma}\left(x, -1, 1\right)} \cdot \left(-2 \cdot \left(-1 - x\right) - x \cdot 1\right)\right)}{\left(-\left(x + -1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    11. *-rgt-identity16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \left(-2 \cdot \left(-1 - x\right) - \color{blue}{x}\right)\right)}{\left(-\left(x + -1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    12. fma-neg16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \color{blue}{\mathsf{fma}\left(-2, -1 - x, -x\right)}\right)}{\left(-\left(x + -1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    13. distribute-neg-in16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\color{blue}{\left(\left(-x\right) + \left(--1\right)\right)} \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    14. neg-mul-116.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\left(\color{blue}{-1 \cdot x} + \left(--1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    15. *-commutative16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\left(\color{blue}{x \cdot -1} + \left(--1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    16. metadata-eval16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\left(x \cdot -1 + \color{blue}{1}\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    17. fma-define16.8%

      \[\leadsto \frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\color{blue}{\mathsf{fma}\left(x, -1, 1\right)} \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
  6. Applied egg-rr16.8%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(-1, x \cdot \left(-1 - x\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)}} \]
  7. Step-by-step derivation
    1. fma-undefine16.8%

      \[\leadsto \frac{\color{blue}{-1 \cdot \left(x \cdot \left(-1 - x\right)\right) + \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)}}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    2. neg-mul-116.8%

      \[\leadsto \frac{\color{blue}{\left(-x \cdot \left(-1 - x\right)\right)} + \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    3. distribute-rgt-neg-in16.8%

      \[\leadsto \frac{\color{blue}{x \cdot \left(-\left(-1 - x\right)\right)} + \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    4. fma-define15.2%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, -\left(-1 - x\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    5. sub-neg15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, -\color{blue}{\left(-1 + \left(-x\right)\right)}, \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    6. distribute-neg-in15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, \color{blue}{\left(--1\right) + \left(-\left(-x\right)\right)}, \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    7. metadata-eval15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, \color{blue}{1} + \left(-\left(-x\right)\right), \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    8. remove-double-neg15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, 1 + \color{blue}{x}, \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    9. +-commutative15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, \color{blue}{x + 1}, \mathsf{fma}\left(x, -1, 1\right) \cdot \mathsf{fma}\left(-2, -1 - x, -x\right)\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    10. *-commutative15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \color{blue}{\mathsf{fma}\left(-2, -1 - x, -x\right) \cdot \mathsf{fma}\left(x, -1, 1\right)}\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    11. fma-neg15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \color{blue}{\left(-2 \cdot \left(-1 - x\right) - x\right)} \cdot \mathsf{fma}\left(x, -1, 1\right)\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    12. fma-undefine15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \left(-2 \cdot \left(-1 - x\right) - x\right) \cdot \color{blue}{\left(x \cdot -1 + 1\right)}\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    13. *-commutative15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \left(-2 \cdot \left(-1 - x\right) - x\right) \cdot \left(\color{blue}{-1 \cdot x} + 1\right)\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    14. neg-mul-115.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \left(-2 \cdot \left(-1 - x\right) - x\right) \cdot \left(\color{blue}{\left(-x\right)} + 1\right)\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    15. +-commutative15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \left(-2 \cdot \left(-1 - x\right) - x\right) \cdot \color{blue}{\left(1 + \left(-x\right)\right)}\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    16. unsub-neg15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \left(-2 \cdot \left(-1 - x\right) - x\right) \cdot \color{blue}{\left(1 - x\right)}\right)}{\mathsf{fma}\left(x, -1, 1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    17. *-commutative15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \left(-2 \cdot \left(-1 - x\right) - x\right) \cdot \left(1 - x\right)\right)}{\color{blue}{\left(x \cdot \left(-1 - x\right)\right) \cdot \mathsf{fma}\left(x, -1, 1\right)}} \]
    18. associate-*l*15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \left(-2 \cdot \left(-1 - x\right) - x\right) \cdot \left(1 - x\right)\right)}{\color{blue}{x \cdot \left(\left(-1 - x\right) \cdot \mathsf{fma}\left(x, -1, 1\right)\right)}} \]
    19. *-commutative15.2%

      \[\leadsto \frac{\mathsf{fma}\left(x, x + 1, \left(-2 \cdot \left(-1 - x\right) - x\right) \cdot \left(1 - x\right)\right)}{x \cdot \color{blue}{\left(\mathsf{fma}\left(x, -1, 1\right) \cdot \left(-1 - x\right)\right)}} \]
  8. Simplified15.2%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x, x + 1, \left(-2 \cdot \left(-1 - x\right) - x\right) \cdot \left(1 - x\right)\right)}{x \cdot \mathsf{fma}\left(x, x, -1\right)}} \]
  9. Taylor expanded in x around 0 99.7%

    \[\leadsto \frac{\color{blue}{2}}{x \cdot \mathsf{fma}\left(x, x, -1\right)} \]
  10. Final simplification99.7%

    \[\leadsto \frac{2}{x \cdot \mathsf{fma}\left(x, x, -1\right)} \]
  11. Add Preprocessing

Alternative 3: 98.9% 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 67.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative67.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg67.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac267.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub067.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified67.0%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 98.9%

    \[\leadsto \color{blue}{\frac{2}{{x}^{3}}} \]
  6. Step-by-step derivation
    1. div-inv98.9%

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

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

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

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

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

Alternative 4: 70.4% 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}
Derivation
  1. Initial program 67.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Add Preprocessing
  3. Final simplification67.0%

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

Alternative 5: 69.2% accurate, 1.2× speedup?

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

\\
\frac{1}{x + -1} + \frac{-1 + \frac{-1}{x}}{x}
\end{array}
Derivation
  1. Initial program 67.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative67.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg67.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac267.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub067.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified67.0%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 66.1%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{-1 \cdot \frac{1 + \frac{1}{x}}{x}} \]
  6. Step-by-step derivation
    1. associate-*r/66.1%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1 \cdot \left(1 + \frac{1}{x}\right)}{x}} \]
    2. neg-mul-166.1%

      \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{-\left(1 + \frac{1}{x}\right)}}{x} \]
    3. distribute-neg-in66.1%

      \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{\left(-1\right) + \left(-\frac{1}{x}\right)}}{x} \]
    4. metadata-eval66.1%

      \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{-1} + \left(-\frac{1}{x}\right)}{x} \]
    5. distribute-neg-frac66.1%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + \color{blue}{\frac{-1}{x}}}{x} \]
    6. metadata-eval66.1%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + \frac{\color{blue}{-1}}{x}}{x} \]
  7. Simplified66.1%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1 + \frac{-1}{x}}{x}} \]
  8. Final simplification66.1%

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

Alternative 6: 68.9% accurate, 1.4× speedup?

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

\\
\frac{x + \left(1 - x\right)}{x \cdot \left(x + -1\right)}
\end{array}
Derivation
  1. Initial program 67.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative67.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg67.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac267.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub067.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified67.0%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 65.8%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1}{x}} \]
  6. Step-by-step derivation
    1. frac-add65.8%

      \[\leadsto \color{blue}{\frac{1 \cdot x + \left(x + -1\right) \cdot -1}{\left(x + -1\right) \cdot x}} \]
    2. *-un-lft-identity65.8%

      \[\leadsto \frac{\color{blue}{x} + \left(x + -1\right) \cdot -1}{\left(x + -1\right) \cdot x} \]
  7. Applied egg-rr65.8%

    \[\leadsto \color{blue}{\frac{x + \left(x + -1\right) \cdot -1}{\left(x + -1\right) \cdot x}} \]
  8. Step-by-step derivation
    1. *-commutative65.8%

      \[\leadsto \frac{x + \color{blue}{-1 \cdot \left(x + -1\right)}}{\left(x + -1\right) \cdot x} \]
    2. distribute-lft-in65.8%

      \[\leadsto \frac{x + \color{blue}{\left(-1 \cdot x + -1 \cdot -1\right)}}{\left(x + -1\right) \cdot x} \]
    3. neg-mul-165.8%

      \[\leadsto \frac{x + \left(\color{blue}{\left(-x\right)} + -1 \cdot -1\right)}{\left(x + -1\right) \cdot x} \]
    4. metadata-eval65.8%

      \[\leadsto \frac{x + \left(\left(-x\right) + \color{blue}{1}\right)}{\left(x + -1\right) \cdot x} \]
    5. +-commutative65.8%

      \[\leadsto \frac{x + \color{blue}{\left(1 + \left(-x\right)\right)}}{\left(x + -1\right) \cdot x} \]
    6. sub-neg65.8%

      \[\leadsto \frac{x + \color{blue}{\left(1 - x\right)}}{\left(x + -1\right) \cdot x} \]
    7. *-commutative65.8%

      \[\leadsto \frac{x + \left(1 - x\right)}{\color{blue}{x \cdot \left(x + -1\right)}} \]
  9. Simplified65.8%

    \[\leadsto \color{blue}{\frac{x + \left(1 - x\right)}{x \cdot \left(x + -1\right)}} \]
  10. Final simplification65.8%

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

Alternative 7: 68.9% 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 67.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative67.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg67.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac267.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub067.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified67.0%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 65.8%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1}{x}} \]
  6. Final simplification65.8%

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

Alternative 8: 52.6% accurate, 2.1× speedup?

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

\\
\frac{\frac{1}{x}}{x + -1}
\end{array}
Derivation
  1. Initial program 67.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative67.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg67.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac267.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub067.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified67.0%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 65.8%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1}{x}} \]
  6. Step-by-step derivation
    1. frac-add65.8%

      \[\leadsto \color{blue}{\frac{1 \cdot x + \left(x + -1\right) \cdot -1}{\left(x + -1\right) \cdot x}} \]
    2. *-un-lft-identity65.8%

      \[\leadsto \frac{\color{blue}{x} + \left(x + -1\right) \cdot -1}{\left(x + -1\right) \cdot x} \]
  7. Applied egg-rr65.8%

    \[\leadsto \color{blue}{\frac{x + \left(x + -1\right) \cdot -1}{\left(x + -1\right) \cdot x}} \]
  8. Step-by-step derivation
    1. *-commutative65.8%

      \[\leadsto \frac{x + \color{blue}{-1 \cdot \left(x + -1\right)}}{\left(x + -1\right) \cdot x} \]
    2. distribute-lft-in65.8%

      \[\leadsto \frac{x + \color{blue}{\left(-1 \cdot x + -1 \cdot -1\right)}}{\left(x + -1\right) \cdot x} \]
    3. neg-mul-165.8%

      \[\leadsto \frac{x + \left(\color{blue}{\left(-x\right)} + -1 \cdot -1\right)}{\left(x + -1\right) \cdot x} \]
    4. metadata-eval65.8%

      \[\leadsto \frac{x + \left(\left(-x\right) + \color{blue}{1}\right)}{\left(x + -1\right) \cdot x} \]
    5. +-commutative65.8%

      \[\leadsto \frac{x + \color{blue}{\left(1 + \left(-x\right)\right)}}{\left(x + -1\right) \cdot x} \]
    6. sub-neg65.8%

      \[\leadsto \frac{x + \color{blue}{\left(1 - x\right)}}{\left(x + -1\right) \cdot x} \]
    7. *-commutative65.8%

      \[\leadsto \frac{x + \left(1 - x\right)}{\color{blue}{x \cdot \left(x + -1\right)}} \]
  9. Simplified65.8%

    \[\leadsto \color{blue}{\frac{x + \left(1 - x\right)}{x \cdot \left(x + -1\right)}} \]
  10. Step-by-step derivation
    1. *-un-lft-identity65.8%

      \[\leadsto \color{blue}{1 \cdot \frac{x + \left(1 - x\right)}{x \cdot \left(x + -1\right)}} \]
  11. Applied egg-rr65.8%

    \[\leadsto \color{blue}{1 \cdot \frac{x + \left(1 - x\right)}{x \cdot \left(x + -1\right)}} \]
  12. Step-by-step derivation
    1. *-lft-identity65.8%

      \[\leadsto \color{blue}{\frac{x + \left(1 - x\right)}{x \cdot \left(x + -1\right)}} \]
    2. +-commutative65.8%

      \[\leadsto \frac{\color{blue}{\left(1 - x\right) + x}}{x \cdot \left(x + -1\right)} \]
    3. associate--r-54.0%

      \[\leadsto \frac{\color{blue}{1 - \left(x - x\right)}}{x \cdot \left(x + -1\right)} \]
    4. +-inverses54.0%

      \[\leadsto \frac{1 - \color{blue}{0}}{x \cdot \left(x + -1\right)} \]
    5. metadata-eval54.0%

      \[\leadsto \frac{\color{blue}{1}}{x \cdot \left(x + -1\right)} \]
    6. associate-/r*52.7%

      \[\leadsto \color{blue}{\frac{\frac{1}{x}}{x + -1}} \]
  13. Simplified52.7%

    \[\leadsto \color{blue}{\frac{\frac{1}{x}}{x + -1}} \]
  14. Final simplification52.7%

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

Alternative 9: 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 67.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative67.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg67.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac267.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub067.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified67.0%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 4.9%

    \[\leadsto \color{blue}{\frac{-2}{x}} \]
  6. Final simplification4.9%

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

Alternative 10: 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 67.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative67.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg67.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac267.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub067.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified67.0%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 65.8%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1}{x}} \]
  6. Taylor expanded in x around 0 4.9%

    \[\leadsto \color{blue}{\frac{-1}{x}} \]
  7. Final simplification4.9%

    \[\leadsto \frac{-1}{x} \]
  8. 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 67.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg67.0%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-67.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub067.0%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg267.0%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+67.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative67.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg67.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac267.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-67.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub067.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified67.0%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 3.3%

    \[\leadsto \frac{1}{x + -1} + \left(\frac{-2}{x} - \color{blue}{-1}\right) \]
  6. Taylor expanded in x around inf 3.3%

    \[\leadsto \color{blue}{1} \]
  7. Final simplification3.3%

    \[\leadsto 1 \]
  8. Add Preprocessing

Developer target: 99.2% 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 2024069 
(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))))