3frac (problem 3.3.3)

Percentage Accurate: 68.4% → 99.5%
Time: 8.6s
Alternatives: 7
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 7 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 68.4% 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: 99.5% accurate, 0.0× speedup?

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

\\
\mathsf{fma}\left(2, {x}^{-2}, 2\right) \cdot {x}^{-3}
\end{array}
Derivation
  1. Initial program 66.3%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative66.3%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-66.3%

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

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

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub066.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-66.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub066.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac266.3%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg266.3%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+66.3%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative66.3%

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

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac266.3%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg66.3%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-66.3%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub066.3%

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

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

    \[\leadsto \color{blue}{\frac{2 + 2 \cdot \frac{1}{{x}^{2}}}{{x}^{3}}} \]
  6. Step-by-step derivation
    1. associate-*r/98.9%

      \[\leadsto \frac{2 + \color{blue}{\frac{2 \cdot 1}{{x}^{2}}}}{{x}^{3}} \]
    2. metadata-eval98.9%

      \[\leadsto \frac{2 + \frac{\color{blue}{2}}{{x}^{2}}}{{x}^{3}} \]
  7. Simplified98.9%

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

      \[\leadsto \color{blue}{\left(2 + \frac{2}{{x}^{2}}\right) \cdot \frac{1}{{x}^{3}}} \]
    2. +-commutative98.9%

      \[\leadsto \color{blue}{\left(\frac{2}{{x}^{2}} + 2\right)} \cdot \frac{1}{{x}^{3}} \]
    3. div-inv98.9%

      \[\leadsto \left(\color{blue}{2 \cdot \frac{1}{{x}^{2}}} + 2\right) \cdot \frac{1}{{x}^{3}} \]
    4. fma-define98.9%

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

      \[\leadsto \mathsf{fma}\left(2, \color{blue}{{x}^{\left(-2\right)}}, 2\right) \cdot \frac{1}{{x}^{3}} \]
    6. metadata-eval98.9%

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

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

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

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

Alternative 2: 99.2% accurate, 1.2× speedup?

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

\\
\frac{1}{\left(-0.5 \cdot \left(x \cdot \left(-1 - x\right)\right)\right) \cdot \left(x + -1\right)}
\end{array}
Derivation
  1. Initial program 66.3%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative66.3%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-66.3%

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

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

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub066.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-66.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub066.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac266.3%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg266.3%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+66.3%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative66.3%

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

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac266.3%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg66.3%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-66.3%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub066.3%

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

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. clear-num66.3%

      \[\leadsto \frac{1}{x + -1} + \left(\color{blue}{\frac{1}{\frac{x}{-2}}} - \frac{1}{-1 - x}\right) \]
    2. frac-sub17.3%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{1 \cdot \left(-1 - x\right) - \frac{x}{-2} \cdot 1}{\frac{x}{-2} \cdot \left(-1 - x\right)}} \]
    3. *-un-lft-identity17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{\left(-1 - x\right)} - \frac{x}{-2} \cdot 1}{\frac{x}{-2} \cdot \left(-1 - x\right)} \]
    4. div-inv17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 - x\right) - \color{blue}{\left(x \cdot \frac{1}{-2}\right)} \cdot 1}{\frac{x}{-2} \cdot \left(-1 - x\right)} \]
    5. metadata-eval17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 - x\right) - \left(x \cdot \color{blue}{-0.5}\right) \cdot 1}{\frac{x}{-2} \cdot \left(-1 - x\right)} \]
    6. div-inv17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 - x\right) - \left(x \cdot -0.5\right) \cdot 1}{\color{blue}{\left(x \cdot \frac{1}{-2}\right)} \cdot \left(-1 - x\right)} \]
    7. metadata-eval17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 - x\right) - \left(x \cdot -0.5\right) \cdot 1}{\left(x \cdot \color{blue}{-0.5}\right) \cdot \left(-1 - x\right)} \]
  6. Applied egg-rr17.3%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{\left(-1 - x\right) - \left(x \cdot -0.5\right) \cdot 1}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)}} \]
  7. Step-by-step derivation
    1. sub-neg17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{\left(-1 - x\right) + \left(-\left(x \cdot -0.5\right) \cdot 1\right)}}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    2. *-rgt-identity17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 - x\right) + \left(-\color{blue}{x \cdot -0.5}\right)}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    3. sub-neg17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{\left(-1 + \left(-x\right)\right)} + \left(-x \cdot -0.5\right)}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    4. neg-mul-117.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 + \left(-x\right)\right) + \color{blue}{-1 \cdot \left(x \cdot -0.5\right)}}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    5. *-commutative17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 + \left(-x\right)\right) + \color{blue}{\left(x \cdot -0.5\right) \cdot -1}}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    6. associate-+l+17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{-1 + \left(\left(-x\right) + \left(x \cdot -0.5\right) \cdot -1\right)}}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    7. neg-mul-117.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + \left(\color{blue}{-1 \cdot x} + \left(x \cdot -0.5\right) \cdot -1\right)}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    8. *-commutative17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + \left(\color{blue}{x \cdot -1} + \left(x \cdot -0.5\right) \cdot -1\right)}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    9. associate-*l*17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + \left(x \cdot -1 + \color{blue}{x \cdot \left(-0.5 \cdot -1\right)}\right)}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    10. distribute-lft-out17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + \color{blue}{x \cdot \left(-1 + -0.5 \cdot -1\right)}}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    11. metadata-eval17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + x \cdot \left(-1 + \color{blue}{0.5}\right)}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    12. metadata-eval17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + x \cdot \color{blue}{-0.5}}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    13. *-commutative17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + x \cdot -0.5}{\color{blue}{\left(-1 - x\right) \cdot \left(x \cdot -0.5\right)}} \]
    14. associate-*r*17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + x \cdot -0.5}{\color{blue}{\left(\left(-1 - x\right) \cdot x\right) \cdot -0.5}} \]
    15. *-commutative17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + x \cdot -0.5}{\color{blue}{\left(x \cdot \left(-1 - x\right)\right)} \cdot -0.5} \]
  8. Simplified17.3%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1 + x \cdot -0.5}{\left(x \cdot \left(-1 - x\right)\right) \cdot -0.5}} \]
  9. Step-by-step derivation
    1. +-commutative17.3%

      \[\leadsto \color{blue}{\frac{-1 + x \cdot -0.5}{\left(x \cdot \left(-1 - x\right)\right) \cdot -0.5} + \frac{1}{x + -1}} \]
    2. frac-add22.8%

      \[\leadsto \color{blue}{\frac{\left(-1 + x \cdot -0.5\right) \cdot \left(x + -1\right) + \left(\left(x \cdot \left(-1 - x\right)\right) \cdot -0.5\right) \cdot 1}{\left(\left(x \cdot \left(-1 - x\right)\right) \cdot -0.5\right) \cdot \left(x + -1\right)}} \]
    3. +-commutative22.8%

      \[\leadsto \frac{\color{blue}{\left(x \cdot -0.5 + -1\right)} \cdot \left(x + -1\right) + \left(\left(x \cdot \left(-1 - x\right)\right) \cdot -0.5\right) \cdot 1}{\left(\left(x \cdot \left(-1 - x\right)\right) \cdot -0.5\right) \cdot \left(x + -1\right)} \]
    4. fma-define22.8%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, -0.5, -1\right)} \cdot \left(x + -1\right) + \left(\left(x \cdot \left(-1 - x\right)\right) \cdot -0.5\right) \cdot 1}{\left(\left(x \cdot \left(-1 - x\right)\right) \cdot -0.5\right) \cdot \left(x + -1\right)} \]
    5. *-commutative22.8%

      \[\leadsto \frac{\mathsf{fma}\left(x, -0.5, -1\right) \cdot \left(x + -1\right) + \color{blue}{\left(-0.5 \cdot \left(x \cdot \left(-1 - x\right)\right)\right)} \cdot 1}{\left(\left(x \cdot \left(-1 - x\right)\right) \cdot -0.5\right) \cdot \left(x + -1\right)} \]
    6. *-commutative22.8%

      \[\leadsto \frac{\mathsf{fma}\left(x, -0.5, -1\right) \cdot \left(x + -1\right) + \left(-0.5 \cdot \left(x \cdot \left(-1 - x\right)\right)\right) \cdot 1}{\color{blue}{\left(-0.5 \cdot \left(x \cdot \left(-1 - x\right)\right)\right)} \cdot \left(x + -1\right)} \]
  10. Applied egg-rr22.8%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x, -0.5, -1\right) \cdot \left(x + -1\right) + \left(-0.5 \cdot \left(x \cdot \left(-1 - x\right)\right)\right) \cdot 1}{\left(-0.5 \cdot \left(x \cdot \left(-1 - x\right)\right)\right) \cdot \left(x + -1\right)}} \]
  11. Taylor expanded in x around 0 22.8%

    \[\leadsto \frac{\color{blue}{\left(1 + x \cdot \left(-0.5 \cdot x - 0.5\right)\right)} + \left(-0.5 \cdot \left(x \cdot \left(-1 - x\right)\right)\right) \cdot 1}{\left(-0.5 \cdot \left(x \cdot \left(-1 - x\right)\right)\right) \cdot \left(x + -1\right)} \]
  12. Taylor expanded in x around 0 99.4%

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

Alternative 3: 71.4% accurate, 1.7× speedup?

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

\\
\frac{\frac{1}{x}}{x \cdot \left(x + -1\right)}
\end{array}
Derivation
  1. Initial program 66.3%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative66.3%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-66.3%

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

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

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub066.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-66.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub066.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac266.3%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg266.3%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+66.3%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative66.3%

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

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac266.3%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg66.3%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-66.3%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub066.3%

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

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 65.1%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{-1 \cdot \frac{1 + \frac{1}{x}}{x}} \]
  6. Step-by-step derivation
    1. associate-*r/65.1%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1 \cdot \left(1 + \frac{1}{x}\right)}{x}} \]
    2. neg-mul-165.1%

      \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{-\left(1 + \frac{1}{x}\right)}}{x} \]
    3. distribute-neg-in65.1%

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

      \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{-1} + \left(-\frac{1}{x}\right)}{x} \]
    5. distribute-neg-frac65.1%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + \color{blue}{\frac{-1}{x}}}{x} \]
    6. metadata-eval65.1%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + \frac{\color{blue}{-1}}{x}}{x} \]
  7. Simplified65.1%

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

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

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

    \[\leadsto \color{blue}{\frac{x + \left(x + -1\right) \cdot \left(-1 + \frac{-1}{x}\right)}{\left(x + -1\right) \cdot x}} \]
  10. Taylor expanded in x around 0 69.5%

    \[\leadsto \frac{\color{blue}{\frac{1}{x}}}{\left(x + -1\right) \cdot x} \]
  11. Final simplification69.5%

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

Alternative 4: 66.9% 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 66.3%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative66.3%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-66.3%

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

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

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub066.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-66.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub066.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac266.3%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg266.3%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+66.3%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative66.3%

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

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac266.3%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg66.3%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-66.3%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub066.3%

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

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 64.5%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1}{x}} \]
  6. Add Preprocessing

Alternative 5: 6.3% 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 66.3%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative66.3%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-66.3%

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

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

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub066.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-66.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub066.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac266.3%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg266.3%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+66.3%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative66.3%

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

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac266.3%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg66.3%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-66.3%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub066.3%

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

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. clear-num66.3%

      \[\leadsto \frac{1}{x + -1} + \left(\color{blue}{\frac{1}{\frac{x}{-2}}} - \frac{1}{-1 - x}\right) \]
    2. frac-sub17.3%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{1 \cdot \left(-1 - x\right) - \frac{x}{-2} \cdot 1}{\frac{x}{-2} \cdot \left(-1 - x\right)}} \]
    3. *-un-lft-identity17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{\left(-1 - x\right)} - \frac{x}{-2} \cdot 1}{\frac{x}{-2} \cdot \left(-1 - x\right)} \]
    4. div-inv17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 - x\right) - \color{blue}{\left(x \cdot \frac{1}{-2}\right)} \cdot 1}{\frac{x}{-2} \cdot \left(-1 - x\right)} \]
    5. metadata-eval17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 - x\right) - \left(x \cdot \color{blue}{-0.5}\right) \cdot 1}{\frac{x}{-2} \cdot \left(-1 - x\right)} \]
    6. div-inv17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 - x\right) - \left(x \cdot -0.5\right) \cdot 1}{\color{blue}{\left(x \cdot \frac{1}{-2}\right)} \cdot \left(-1 - x\right)} \]
    7. metadata-eval17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 - x\right) - \left(x \cdot -0.5\right) \cdot 1}{\left(x \cdot \color{blue}{-0.5}\right) \cdot \left(-1 - x\right)} \]
  6. Applied egg-rr17.3%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{\left(-1 - x\right) - \left(x \cdot -0.5\right) \cdot 1}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)}} \]
  7. Step-by-step derivation
    1. sub-neg17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{\left(-1 - x\right) + \left(-\left(x \cdot -0.5\right) \cdot 1\right)}}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    2. *-rgt-identity17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 - x\right) + \left(-\color{blue}{x \cdot -0.5}\right)}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    3. sub-neg17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{\left(-1 + \left(-x\right)\right)} + \left(-x \cdot -0.5\right)}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    4. neg-mul-117.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 + \left(-x\right)\right) + \color{blue}{-1 \cdot \left(x \cdot -0.5\right)}}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    5. *-commutative17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 + \left(-x\right)\right) + \color{blue}{\left(x \cdot -0.5\right) \cdot -1}}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    6. associate-+l+17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{-1 + \left(\left(-x\right) + \left(x \cdot -0.5\right) \cdot -1\right)}}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    7. neg-mul-117.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + \left(\color{blue}{-1 \cdot x} + \left(x \cdot -0.5\right) \cdot -1\right)}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    8. *-commutative17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + \left(\color{blue}{x \cdot -1} + \left(x \cdot -0.5\right) \cdot -1\right)}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    9. associate-*l*17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + \left(x \cdot -1 + \color{blue}{x \cdot \left(-0.5 \cdot -1\right)}\right)}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    10. distribute-lft-out17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + \color{blue}{x \cdot \left(-1 + -0.5 \cdot -1\right)}}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    11. metadata-eval17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + x \cdot \left(-1 + \color{blue}{0.5}\right)}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    12. metadata-eval17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + x \cdot \color{blue}{-0.5}}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    13. *-commutative17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + x \cdot -0.5}{\color{blue}{\left(-1 - x\right) \cdot \left(x \cdot -0.5\right)}} \]
    14. associate-*r*17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + x \cdot -0.5}{\color{blue}{\left(\left(-1 - x\right) \cdot x\right) \cdot -0.5}} \]
    15. *-commutative17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + x \cdot -0.5}{\color{blue}{\left(x \cdot \left(-1 - x\right)\right)} \cdot -0.5} \]
  8. Simplified17.3%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1 + x \cdot -0.5}{\left(x \cdot \left(-1 - x\right)\right) \cdot -0.5}} \]
  9. Taylor expanded in x around inf 15.7%

    \[\leadsto \color{blue}{\frac{1}{x}} + \frac{-1 + x \cdot -0.5}{\left(x \cdot \left(-1 - x\right)\right) \cdot -0.5} \]
  10. Taylor expanded in x around 0 4.8%

    \[\leadsto \color{blue}{\frac{-1}{x}} \]
  11. Step-by-step derivation
    1. div-inv4.8%

      \[\leadsto \color{blue}{-1 \cdot \frac{1}{x}} \]
    2. metadata-eval4.8%

      \[\leadsto -1 \cdot \frac{\color{blue}{--1}}{x} \]
    3. add-sqr-sqrt2.4%

      \[\leadsto -1 \cdot \frac{--1}{\color{blue}{\sqrt{x} \cdot \sqrt{x}}} \]
    4. sqrt-prod48.2%

      \[\leadsto -1 \cdot \frac{--1}{\color{blue}{\sqrt{x \cdot x}}} \]
    5. sqr-neg48.2%

      \[\leadsto -1 \cdot \frac{--1}{\sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)}}} \]
    6. pow248.2%

      \[\leadsto -1 \cdot \frac{--1}{\sqrt{\color{blue}{{\left(-x\right)}^{2}}}} \]
    7. sqrt-pow16.3%

      \[\leadsto -1 \cdot \frac{--1}{\color{blue}{{\left(-x\right)}^{\left(\frac{2}{2}\right)}}} \]
    8. metadata-eval6.3%

      \[\leadsto -1 \cdot \frac{--1}{{\left(-x\right)}^{\color{blue}{1}}} \]
    9. pow16.3%

      \[\leadsto -1 \cdot \frac{--1}{\color{blue}{-x}} \]
    10. frac-2neg6.3%

      \[\leadsto -1 \cdot \color{blue}{\frac{-1}{x}} \]
  12. Applied egg-rr6.3%

    \[\leadsto \color{blue}{-1 \cdot \frac{-1}{x}} \]
  13. Step-by-step derivation
    1. associate-*r/6.3%

      \[\leadsto \color{blue}{\frac{-1 \cdot -1}{x}} \]
    2. metadata-eval6.3%

      \[\leadsto \frac{\color{blue}{1}}{x} \]
  14. Simplified6.3%

    \[\leadsto \color{blue}{\frac{1}{x}} \]
  15. Add Preprocessing

Alternative 6: 5.0% 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 66.3%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative66.3%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-66.3%

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

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

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub066.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-66.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub066.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac266.3%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg266.3%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+66.3%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative66.3%

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

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac266.3%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg66.3%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-66.3%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub066.3%

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

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. clear-num66.3%

      \[\leadsto \frac{1}{x + -1} + \left(\color{blue}{\frac{1}{\frac{x}{-2}}} - \frac{1}{-1 - x}\right) \]
    2. frac-sub17.3%

      \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{1 \cdot \left(-1 - x\right) - \frac{x}{-2} \cdot 1}{\frac{x}{-2} \cdot \left(-1 - x\right)}} \]
    3. *-un-lft-identity17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{\left(-1 - x\right)} - \frac{x}{-2} \cdot 1}{\frac{x}{-2} \cdot \left(-1 - x\right)} \]
    4. div-inv17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 - x\right) - \color{blue}{\left(x \cdot \frac{1}{-2}\right)} \cdot 1}{\frac{x}{-2} \cdot \left(-1 - x\right)} \]
    5. metadata-eval17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 - x\right) - \left(x \cdot \color{blue}{-0.5}\right) \cdot 1}{\frac{x}{-2} \cdot \left(-1 - x\right)} \]
    6. div-inv17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 - x\right) - \left(x \cdot -0.5\right) \cdot 1}{\color{blue}{\left(x \cdot \frac{1}{-2}\right)} \cdot \left(-1 - x\right)} \]
    7. metadata-eval17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 - x\right) - \left(x \cdot -0.5\right) \cdot 1}{\left(x \cdot \color{blue}{-0.5}\right) \cdot \left(-1 - x\right)} \]
  6. Applied egg-rr17.3%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{\left(-1 - x\right) - \left(x \cdot -0.5\right) \cdot 1}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)}} \]
  7. Step-by-step derivation
    1. sub-neg17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{\left(-1 - x\right) + \left(-\left(x \cdot -0.5\right) \cdot 1\right)}}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    2. *-rgt-identity17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 - x\right) + \left(-\color{blue}{x \cdot -0.5}\right)}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    3. sub-neg17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{\left(-1 + \left(-x\right)\right)} + \left(-x \cdot -0.5\right)}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    4. neg-mul-117.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 + \left(-x\right)\right) + \color{blue}{-1 \cdot \left(x \cdot -0.5\right)}}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    5. *-commutative17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(-1 + \left(-x\right)\right) + \color{blue}{\left(x \cdot -0.5\right) \cdot -1}}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    6. associate-+l+17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{-1 + \left(\left(-x\right) + \left(x \cdot -0.5\right) \cdot -1\right)}}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    7. neg-mul-117.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + \left(\color{blue}{-1 \cdot x} + \left(x \cdot -0.5\right) \cdot -1\right)}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    8. *-commutative17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + \left(\color{blue}{x \cdot -1} + \left(x \cdot -0.5\right) \cdot -1\right)}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    9. associate-*l*17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + \left(x \cdot -1 + \color{blue}{x \cdot \left(-0.5 \cdot -1\right)}\right)}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    10. distribute-lft-out17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + \color{blue}{x \cdot \left(-1 + -0.5 \cdot -1\right)}}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    11. metadata-eval17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + x \cdot \left(-1 + \color{blue}{0.5}\right)}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    12. metadata-eval17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + x \cdot \color{blue}{-0.5}}{\left(x \cdot -0.5\right) \cdot \left(-1 - x\right)} \]
    13. *-commutative17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + x \cdot -0.5}{\color{blue}{\left(-1 - x\right) \cdot \left(x \cdot -0.5\right)}} \]
    14. associate-*r*17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + x \cdot -0.5}{\color{blue}{\left(\left(-1 - x\right) \cdot x\right) \cdot -0.5}} \]
    15. *-commutative17.3%

      \[\leadsto \frac{1}{x + -1} + \frac{-1 + x \cdot -0.5}{\color{blue}{\left(x \cdot \left(-1 - x\right)\right)} \cdot -0.5} \]
  8. Simplified17.3%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1 + x \cdot -0.5}{\left(x \cdot \left(-1 - x\right)\right) \cdot -0.5}} \]
  9. Taylor expanded in x around inf 15.7%

    \[\leadsto \color{blue}{\frac{1}{x}} + \frac{-1 + x \cdot -0.5}{\left(x \cdot \left(-1 - x\right)\right) \cdot -0.5} \]
  10. Taylor expanded in x around 0 4.8%

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

Alternative 7: 5.0% 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 66.3%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative66.3%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-66.3%

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

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

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub066.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-66.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub066.3%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac266.3%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg266.3%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+66.3%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative66.3%

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

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac266.3%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg66.3%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-66.3%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub066.3%

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

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 4.7%

    \[\leadsto \color{blue}{\frac{-2}{x}} \]
  6. Add Preprocessing

Developer Target 1: 99.1% 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 2024148 
(FPCore (x)
  :name "3frac (problem 3.3.3)"
  :precision binary64
  :pre (> (fabs x) 1.0)

  :alt
  (! :herbie-platform default (/ 2 (* x (- (* x x) 1))))

  (+ (- (/ 1.0 (+ x 1.0)) (/ 2.0 x)) (/ 1.0 (- x 1.0))))