3frac (problem 3.3.3)

Percentage Accurate: 69.4% → 99.6%
Time: 9.6s
Alternatives: 9
Speedup: 1.2×

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 9 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: 69.4% 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: 99.6% accurate, 0.0× speedup?

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

\\
\mathsf{fma}\left(2, {x}^{-2}, \mathsf{fma}\left(2, {x}^{-4}, 2\right)\right) \cdot {x}^{-3}
\end{array}
Derivation
  1. Initial program 62.8%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative62.8%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-62.7%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg62.7%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg62.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub062.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-62.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub062.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac262.7%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg262.7%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+62.8%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative62.8%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg62.8%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac262.8%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg62.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-62.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub062.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified62.8%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 98.4%

    \[\leadsto \color{blue}{\frac{2 + \left(2 \cdot \frac{1}{{x}^{2}} + \frac{2}{{x}^{4}}\right)}{{x}^{3}}} \]
  6. Step-by-step derivation
    1. associate-+r+98.4%

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

      \[\leadsto \frac{\color{blue}{\left(2 \cdot \frac{1}{{x}^{2}} + 2\right)} + \frac{2}{{x}^{4}}}{{x}^{3}} \]
    3. associate-+l+98.4%

      \[\leadsto \frac{\color{blue}{2 \cdot \frac{1}{{x}^{2}} + \left(2 + \frac{2}{{x}^{4}}\right)}}{{x}^{3}} \]
    4. associate-*r/98.4%

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \mathsf{fma}\left(2, {x}^{-2}, \mathsf{fma}\left(2, {x}^{\color{blue}{-4}}, 2\right)\right) \cdot \frac{1}{{x}^{3}} \]
    11. pow-flip99.8%

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

      \[\leadsto \mathsf{fma}\left(2, {x}^{-2}, \mathsf{fma}\left(2, {x}^{-4}, 2\right)\right) \cdot {x}^{\color{blue}{-3}} \]
  9. Applied egg-rr99.8%

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

Alternative 2: 99.4% accurate, 0.1× speedup?

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

\\
{x}^{-3} \cdot \left(2 + \frac{2}{x \cdot x}\right)
\end{array}
Derivation
  1. Initial program 62.8%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative62.8%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-62.7%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg62.7%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg62.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub062.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-62.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub062.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac262.7%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg262.7%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+62.8%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative62.8%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg62.8%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac262.8%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg62.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-62.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub062.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified62.8%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 98.4%

    \[\leadsto \color{blue}{\frac{2 + \left(2 \cdot \frac{1}{{x}^{2}} + \frac{2}{{x}^{4}}\right)}{{x}^{3}}} \]
  6. Step-by-step derivation
    1. associate-+r+98.4%

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

      \[\leadsto \frac{\color{blue}{\left(2 \cdot \frac{1}{{x}^{2}} + 2\right)} + \frac{2}{{x}^{4}}}{{x}^{3}} \]
    3. associate-+l+98.4%

      \[\leadsto \frac{\color{blue}{2 \cdot \frac{1}{{x}^{2}} + \left(2 + \frac{2}{{x}^{4}}\right)}}{{x}^{3}} \]
    4. associate-*r/98.4%

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \mathsf{fma}\left(2, {x}^{-2}, \mathsf{fma}\left(2, {x}^{\color{blue}{-4}}, 2\right)\right) \cdot \frac{1}{{x}^{3}} \]
    11. pow-flip99.8%

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

      \[\leadsto \mathsf{fma}\left(2, {x}^{-2}, \mathsf{fma}\left(2, {x}^{-4}, 2\right)\right) \cdot {x}^{\color{blue}{-3}} \]
  9. Applied egg-rr99.8%

    \[\leadsto \color{blue}{\mathsf{fma}\left(2, {x}^{-2}, \mathsf{fma}\left(2, {x}^{-4}, 2\right)\right) \cdot {x}^{-3}} \]
  10. Taylor expanded in x around inf 99.7%

    \[\leadsto \color{blue}{\left(2 + 2 \cdot \frac{1}{{x}^{2}}\right)} \cdot {x}^{-3} \]
  11. Step-by-step derivation
    1. associate-*r/99.7%

      \[\leadsto \left(2 + \color{blue}{\frac{2 \cdot 1}{{x}^{2}}}\right) \cdot {x}^{-3} \]
    2. metadata-eval99.7%

      \[\leadsto \left(2 + \frac{\color{blue}{2}}{{x}^{2}}\right) \cdot {x}^{-3} \]
  12. Simplified99.7%

    \[\leadsto \color{blue}{\left(2 + \frac{2}{{x}^{2}}\right)} \cdot {x}^{-3} \]
  13. Step-by-step derivation
    1. unpow299.7%

      \[\leadsto \left(2 + \frac{2}{\color{blue}{x \cdot x}}\right) \cdot {x}^{-3} \]
  14. Applied egg-rr99.7%

    \[\leadsto \left(2 + \frac{2}{\color{blue}{x \cdot x}}\right) \cdot {x}^{-3} \]
  15. Final simplification99.7%

    \[\leadsto {x}^{-3} \cdot \left(2 + \frac{2}{x \cdot x}\right) \]
  16. 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 62.8%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative62.8%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-62.7%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg62.7%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg62.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub062.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-62.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub062.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac262.7%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg262.7%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+62.8%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative62.8%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg62.8%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac262.8%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg62.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-62.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub062.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified62.8%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 98.4%

    \[\leadsto \color{blue}{\frac{2 + \left(2 \cdot \frac{1}{{x}^{2}} + \frac{2}{{x}^{4}}\right)}{{x}^{3}}} \]
  6. Step-by-step derivation
    1. associate-+r+98.4%

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

      \[\leadsto \frac{\color{blue}{\left(2 \cdot \frac{1}{{x}^{2}} + 2\right)} + \frac{2}{{x}^{4}}}{{x}^{3}} \]
    3. associate-+l+98.4%

      \[\leadsto \frac{\color{blue}{2 \cdot \frac{1}{{x}^{2}} + \left(2 + \frac{2}{{x}^{4}}\right)}}{{x}^{3}} \]
    4. associate-*r/98.4%

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \mathsf{fma}\left(2, {x}^{-2}, \mathsf{fma}\left(2, {x}^{\color{blue}{-4}}, 2\right)\right) \cdot \frac{1}{{x}^{3}} \]
    11. pow-flip99.8%

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

      \[\leadsto \mathsf{fma}\left(2, {x}^{-2}, \mathsf{fma}\left(2, {x}^{-4}, 2\right)\right) \cdot {x}^{\color{blue}{-3}} \]
  9. Applied egg-rr99.8%

    \[\leadsto \color{blue}{\mathsf{fma}\left(2, {x}^{-2}, \mathsf{fma}\left(2, {x}^{-4}, 2\right)\right) \cdot {x}^{-3}} \]
  10. Taylor expanded in x around inf 99.1%

    \[\leadsto \color{blue}{2} \cdot {x}^{-3} \]
  11. Add Preprocessing

Alternative 4: 97.9% accurate, 1.2× speedup?

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

\\
\frac{\frac{2 - \frac{1}{x}}{x}}{x \cdot \left(x + -1\right)}
\end{array}
Derivation
  1. Initial program 62.8%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative62.8%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-62.7%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg62.7%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg62.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub062.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-62.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub062.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac262.7%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg262.7%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+62.8%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative62.8%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg62.8%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac262.8%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg62.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-62.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub062.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified62.8%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 62.3%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{\frac{1}{{x}^{2}} - \left(1 + \frac{1}{x}\right)}{x}} \]
  6. Step-by-step derivation
    1. +-commutative62.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\frac{1}{{x}^{2}} - \color{blue}{\left(\frac{1}{x} + 1\right)}}{x} \]
    2. associate--r+62.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{\left(\frac{1}{{x}^{2}} - \frac{1}{x}\right) - 1}}{x} \]
    3. unpow262.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(\frac{1}{\color{blue}{x \cdot x}} - \frac{1}{x}\right) - 1}{x} \]
    4. associate-/r*62.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\left(\color{blue}{\frac{\frac{1}{x}}{x}} - \frac{1}{x}\right) - 1}{x} \]
    5. div-sub62.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\color{blue}{\frac{\frac{1}{x} - 1}{x}} - 1}{x} \]
    6. sub-neg62.3%

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

      \[\leadsto \frac{1}{x + -1} + \frac{\frac{\frac{1}{x} + \color{blue}{-1}}{x} - 1}{x} \]
    8. +-commutative62.3%

      \[\leadsto \frac{1}{x + -1} + \frac{\frac{\color{blue}{-1 + \frac{1}{x}}}{x} - 1}{x} \]
  7. Simplified62.3%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{\frac{-1 + \frac{1}{x}}{x} - 1}{x}} \]
  8. Step-by-step derivation
    1. frac-add62.3%

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

      \[\leadsto \frac{\color{blue}{x} + \left(x + -1\right) \cdot \left(\frac{-1 + \frac{1}{x}}{x} - 1\right)}{\left(x + -1\right) \cdot x} \]
    3. sub-neg62.3%

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

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

    \[\leadsto \color{blue}{\frac{x + \left(x + -1\right) \cdot \left(\frac{-1 + \frac{1}{x}}{x} + -1\right)}{\left(x + -1\right) \cdot x}} \]
  10. Taylor expanded in x around 0 96.4%

    \[\leadsto \frac{\color{blue}{\frac{2 \cdot x - 1}{{x}^{2}}}}{\left(x + -1\right) \cdot x} \]
  11. Step-by-step derivation
    1. div-sub96.4%

      \[\leadsto \frac{\color{blue}{\frac{2 \cdot x}{{x}^{2}} - \frac{1}{{x}^{2}}}}{\left(x + -1\right) \cdot x} \]
    2. *-commutative96.4%

      \[\leadsto \frac{\frac{\color{blue}{x \cdot 2}}{{x}^{2}} - \frac{1}{{x}^{2}}}{\left(x + -1\right) \cdot x} \]
    3. unpow296.4%

      \[\leadsto \frac{\frac{x \cdot 2}{\color{blue}{x \cdot x}} - \frac{1}{{x}^{2}}}{\left(x + -1\right) \cdot x} \]
    4. times-frac97.3%

      \[\leadsto \frac{\color{blue}{\frac{x}{x} \cdot \frac{2}{x}} - \frac{1}{{x}^{2}}}{\left(x + -1\right) \cdot x} \]
    5. *-inverses97.3%

      \[\leadsto \frac{\color{blue}{1} \cdot \frac{2}{x} - \frac{1}{{x}^{2}}}{\left(x + -1\right) \cdot x} \]
    6. unpow297.3%

      \[\leadsto \frac{1 \cdot \frac{2}{x} - \frac{1}{\color{blue}{x \cdot x}}}{\left(x + -1\right) \cdot x} \]
    7. associate-/r*97.3%

      \[\leadsto \frac{1 \cdot \frac{2}{x} - \color{blue}{\frac{\frac{1}{x}}{x}}}{\left(x + -1\right) \cdot x} \]
    8. *-lft-identity97.3%

      \[\leadsto \frac{\color{blue}{\frac{2}{x}} - \frac{\frac{1}{x}}{x}}{\left(x + -1\right) \cdot x} \]
    9. div-sub97.3%

      \[\leadsto \frac{\color{blue}{\frac{2 - \frac{1}{x}}{x}}}{\left(x + -1\right) \cdot x} \]
  12. Simplified97.3%

    \[\leadsto \frac{\color{blue}{\frac{2 - \frac{1}{x}}{x}}}{\left(x + -1\right) \cdot x} \]
  13. Final simplification97.3%

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

Alternative 5: 68.1% 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 62.8%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative62.8%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-62.7%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg62.7%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg62.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub062.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-62.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub062.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac262.7%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg262.7%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+62.8%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative62.8%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg62.8%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac262.8%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg62.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-62.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub062.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified62.8%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 61.6%

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

Alternative 6: 67.8% accurate, 2.1× speedup?

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

\\
-1 + \frac{x - 2}{x}
\end{array}
Derivation
  1. Initial program 62.8%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative62.8%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-62.7%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg62.7%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg62.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub062.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-62.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub062.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac262.7%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg262.7%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+62.8%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative62.8%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg62.8%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac262.8%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg62.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-62.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub062.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified62.8%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 3.4%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{x - 2}{x}} \]
  6. Taylor expanded in x around 0 61.3%

    \[\leadsto \color{blue}{-1} + \frac{x - 2}{x} \]
  7. Add Preprocessing

Alternative 7: 6.3% accurate, 5.0× speedup?

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

\\
\frac{2}{x}
\end{array}
Derivation
  1. Initial program 62.8%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative62.8%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-62.7%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg62.7%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg62.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub062.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-62.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub062.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac262.7%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg262.7%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+62.8%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative62.8%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg62.8%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac262.8%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg62.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-62.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub062.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified62.8%

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

    \[\leadsto \color{blue}{\frac{-2}{x}} \]
  6. Step-by-step derivation
    1. *-un-lft-identity4.9%

      \[\leadsto \color{blue}{1 \cdot \frac{-2}{x}} \]
    2. frac-2neg4.9%

      \[\leadsto 1 \cdot \color{blue}{\frac{--2}{-x}} \]
    3. metadata-eval4.9%

      \[\leadsto 1 \cdot \frac{\color{blue}{2}}{-x} \]
    4. pow14.9%

      \[\leadsto 1 \cdot \frac{2}{\color{blue}{{\left(-x\right)}^{1}}} \]
    5. metadata-eval4.9%

      \[\leadsto 1 \cdot \frac{2}{{\left(-x\right)}^{\color{blue}{\left(\frac{2}{2}\right)}}} \]
    6. sqrt-pow146.2%

      \[\leadsto 1 \cdot \frac{2}{\color{blue}{\sqrt{{\left(-x\right)}^{2}}}} \]
    7. pow246.2%

      \[\leadsto 1 \cdot \frac{2}{\sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)}}} \]
    8. sqr-neg46.2%

      \[\leadsto 1 \cdot \frac{2}{\sqrt{\color{blue}{x \cdot x}}} \]
    9. sqrt-prod3.1%

      \[\leadsto 1 \cdot \frac{2}{\color{blue}{\sqrt{x} \cdot \sqrt{x}}} \]
    10. add-sqr-sqrt6.3%

      \[\leadsto 1 \cdot \frac{2}{\color{blue}{x}} \]
  7. Applied egg-rr6.3%

    \[\leadsto \color{blue}{1 \cdot \frac{2}{x}} \]
  8. Step-by-step derivation
    1. *-lft-identity6.3%

      \[\leadsto \color{blue}{\frac{2}{x}} \]
  9. Simplified6.3%

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

Alternative 8: 5.1% accurate, 5.0× speedup?

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

\\
\frac{-2}{x}
\end{array}
Derivation
  1. Initial program 62.8%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative62.8%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-62.7%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg62.7%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg62.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub062.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-62.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub062.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac262.7%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg262.7%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+62.8%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative62.8%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg62.8%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac262.8%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg62.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-62.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub062.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified62.8%

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

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

Alternative 9: 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 62.8%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative62.8%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-62.7%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg62.7%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg62.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub062.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-62.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub062.7%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac262.7%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg262.7%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+62.8%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative62.8%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg62.8%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac262.8%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg62.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-62.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(0 - x\right) + 1}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    16. neg-sub062.8%

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified62.8%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 3.4%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{x - 2}{x}} \]
  6. Taylor expanded in x around inf 3.4%

    \[\leadsto \color{blue}{1} \]
  7. 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 2024130 
(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))))