3frac (problem 3.3.3)

Percentage Accurate: 70.0% → 99.8%
Time: 10.1s
Alternatives: 10
Speedup: 1.4×

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 10 alternatives:

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

Initial Program: 70.0% accurate, 1.0× speedup?

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

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

Alternative 1: 99.8% accurate, 1.2× speedup?

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

\\
\frac{\frac{1}{x}}{\left(x + -1\right) \cdot \left(-1 - x\right)} \cdot -2
\end{array}
Derivation
  1. Initial program 66.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative66.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg66.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac266.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg66.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-66.0%

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

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified66.0%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. +-commutative66.0%

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

      \[\leadsto \color{blue}{\frac{-2 \cdot \left(-1 - x\right) - x \cdot 1}{x \cdot \left(-1 - x\right)}} + \frac{1}{x + -1} \]
    3. frac-add19.5%

      \[\leadsto \color{blue}{\frac{\left(-2 \cdot \left(-1 - x\right) - x \cdot 1\right) \cdot \left(x + -1\right) + \left(x \cdot \left(-1 - x\right)\right) \cdot 1}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)}} \]
    4. fma-define18.7%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(-2 \cdot \left(-1 - x\right) - x \cdot 1, x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
    5. *-rgt-identity18.7%

      \[\leadsto \frac{\mathsf{fma}\left(-2 \cdot \left(-1 - x\right) - \color{blue}{x}, x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
    6. fma-neg18.7%

      \[\leadsto \frac{\mathsf{fma}\left(\color{blue}{\mathsf{fma}\left(-2, -1 - x, -x\right)}, x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
  6. Applied egg-rr18.7%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\mathsf{fma}\left(-2, -1 - x, -x\right), x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)}} \]
  7. Taylor expanded in x around 0 99.4%

    \[\leadsto \frac{\color{blue}{-2}}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
  8. Step-by-step derivation
    1. clear-num99.4%

      \[\leadsto \color{blue}{\frac{1}{\frac{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)}{-2}}} \]
    2. associate-/r/99.4%

      \[\leadsto \color{blue}{\frac{1}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \cdot -2} \]
    3. associate-*l*99.4%

      \[\leadsto \frac{1}{\color{blue}{x \cdot \left(\left(-1 - x\right) \cdot \left(x + -1\right)\right)}} \cdot -2 \]
    4. associate-/r*99.9%

      \[\leadsto \color{blue}{\frac{\frac{1}{x}}{\left(-1 - x\right) \cdot \left(x + -1\right)}} \cdot -2 \]
    5. *-commutative99.9%

      \[\leadsto \frac{\frac{1}{x}}{\color{blue}{\left(x + -1\right) \cdot \left(-1 - x\right)}} \cdot -2 \]
  9. Applied egg-rr99.9%

    \[\leadsto \color{blue}{\frac{\frac{1}{x}}{\left(x + -1\right) \cdot \left(-1 - x\right)} \cdot -2} \]
  10. Final simplification99.9%

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

Alternative 2: 99.7% accurate, 1.2× speedup?

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

\\
\frac{\frac{-2}{x}}{-1 - x} \cdot \frac{1}{x + -1}
\end{array}
Derivation
  1. Initial program 66.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative66.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg66.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac266.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg66.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-66.0%

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

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified66.0%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. +-commutative66.0%

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

      \[\leadsto \color{blue}{\frac{-2 \cdot \left(-1 - x\right) - x \cdot 1}{x \cdot \left(-1 - x\right)}} + \frac{1}{x + -1} \]
    3. frac-add19.5%

      \[\leadsto \color{blue}{\frac{\left(-2 \cdot \left(-1 - x\right) - x \cdot 1\right) \cdot \left(x + -1\right) + \left(x \cdot \left(-1 - x\right)\right) \cdot 1}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)}} \]
    4. fma-define18.7%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(-2 \cdot \left(-1 - x\right) - x \cdot 1, x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
    5. *-rgt-identity18.7%

      \[\leadsto \frac{\mathsf{fma}\left(-2 \cdot \left(-1 - x\right) - \color{blue}{x}, x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
    6. fma-neg18.7%

      \[\leadsto \frac{\mathsf{fma}\left(\color{blue}{\mathsf{fma}\left(-2, -1 - x, -x\right)}, x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
  6. Applied egg-rr18.7%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\mathsf{fma}\left(-2, -1 - x, -x\right), x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)}} \]
  7. Taylor expanded in x around 0 99.4%

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

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

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

      \[\leadsto \color{blue}{\frac{\frac{-2}{x}}{-1 - x}} \cdot \frac{1}{x + -1} \]
  9. Applied egg-rr99.7%

    \[\leadsto \color{blue}{\frac{\frac{-2}{x}}{-1 - x} \cdot \frac{1}{x + -1}} \]
  10. Final simplification99.7%

    \[\leadsto \frac{\frac{-2}{x}}{-1 - x} \cdot \frac{1}{x + -1} \]
  11. Add Preprocessing

Alternative 3: 99.3% accurate, 1.4× speedup?

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

\\
\frac{-2}{\left(x + -1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)}
\end{array}
Derivation
  1. Initial program 66.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative66.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg66.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac266.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg66.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-66.0%

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

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified66.0%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. +-commutative66.0%

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

      \[\leadsto \color{blue}{\frac{-2 \cdot \left(-1 - x\right) - x \cdot 1}{x \cdot \left(-1 - x\right)}} + \frac{1}{x + -1} \]
    3. frac-add19.5%

      \[\leadsto \color{blue}{\frac{\left(-2 \cdot \left(-1 - x\right) - x \cdot 1\right) \cdot \left(x + -1\right) + \left(x \cdot \left(-1 - x\right)\right) \cdot 1}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)}} \]
    4. fma-define18.7%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(-2 \cdot \left(-1 - x\right) - x \cdot 1, x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
    5. *-rgt-identity18.7%

      \[\leadsto \frac{\mathsf{fma}\left(-2 \cdot \left(-1 - x\right) - \color{blue}{x}, x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
    6. fma-neg18.7%

      \[\leadsto \frac{\mathsf{fma}\left(\color{blue}{\mathsf{fma}\left(-2, -1 - x, -x\right)}, x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
  6. Applied egg-rr18.7%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\mathsf{fma}\left(-2, -1 - x, -x\right), x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)}} \]
  7. Taylor expanded in x around 0 99.4%

    \[\leadsto \frac{\color{blue}{-2}}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
  8. Final simplification99.4%

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

Alternative 4: 99.3% accurate, 1.4× speedup?

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

\\
\frac{2}{\left(-1 - x\right) \cdot \left(x \cdot \left(1 - x\right)\right)}
\end{array}
Derivation
  1. Initial program 66.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative66.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg66.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac266.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg66.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-66.0%

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

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified66.0%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. +-commutative66.0%

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

      \[\leadsto \color{blue}{\frac{-2 \cdot \left(-1 - x\right) - x \cdot 1}{x \cdot \left(-1 - x\right)}} + \frac{1}{x + -1} \]
    3. frac-add19.5%

      \[\leadsto \color{blue}{\frac{\left(-2 \cdot \left(-1 - x\right) - x \cdot 1\right) \cdot \left(x + -1\right) + \left(x \cdot \left(-1 - x\right)\right) \cdot 1}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)}} \]
    4. fma-define18.7%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(-2 \cdot \left(-1 - x\right) - x \cdot 1, x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
    5. *-rgt-identity18.7%

      \[\leadsto \frac{\mathsf{fma}\left(-2 \cdot \left(-1 - x\right) - \color{blue}{x}, x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
    6. fma-neg18.7%

      \[\leadsto \frac{\mathsf{fma}\left(\color{blue}{\mathsf{fma}\left(-2, -1 - x, -x\right)}, x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
  6. Applied egg-rr18.7%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\mathsf{fma}\left(-2, -1 - x, -x\right), x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)}} \]
  7. Taylor expanded in x around 0 99.4%

    \[\leadsto \frac{\color{blue}{-2}}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
  8. Step-by-step derivation
    1. frac-2neg99.4%

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

      \[\leadsto \frac{\color{blue}{2}}{-\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
    3. div-inv99.4%

      \[\leadsto \color{blue}{2 \cdot \frac{1}{-\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)}} \]
    4. *-commutative99.4%

      \[\leadsto 2 \cdot \frac{1}{-\color{blue}{\left(x + -1\right) \cdot \left(x \cdot \left(-1 - x\right)\right)}} \]
    5. distribute-lft-neg-in99.4%

      \[\leadsto 2 \cdot \frac{1}{\color{blue}{\left(-\left(x + -1\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)}} \]
    6. +-commutative99.4%

      \[\leadsto 2 \cdot \frac{1}{\left(-\color{blue}{\left(-1 + x\right)}\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    7. distribute-neg-in99.4%

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

      \[\leadsto 2 \cdot \frac{1}{\left(\color{blue}{1} + \left(-x\right)\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    9. sub-neg99.4%

      \[\leadsto 2 \cdot \frac{1}{\color{blue}{\left(1 - x\right)} \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
  9. Applied egg-rr99.4%

    \[\leadsto \color{blue}{2 \cdot \frac{1}{\left(1 - x\right) \cdot \left(x \cdot \left(-1 - x\right)\right)}} \]
  10. Step-by-step derivation
    1. associate-*r/99.4%

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

      \[\leadsto \frac{\color{blue}{2}}{\left(1 - x\right) \cdot \left(x \cdot \left(-1 - x\right)\right)} \]
    3. associate-*r*99.4%

      \[\leadsto \frac{2}{\color{blue}{\left(\left(1 - x\right) \cdot x\right) \cdot \left(-1 - x\right)}} \]
    4. *-commutative99.4%

      \[\leadsto \frac{2}{\color{blue}{\left(x \cdot \left(1 - x\right)\right)} \cdot \left(-1 - x\right)} \]
  11. Simplified99.4%

    \[\leadsto \color{blue}{\frac{2}{\left(x \cdot \left(1 - x\right)\right) \cdot \left(-1 - x\right)}} \]
  12. Final simplification99.4%

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

Alternative 5: 68.6% 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 66.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative66.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg66.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac266.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg66.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-66.0%

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

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified66.0%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 64.6%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1}{x}} \]
  6. Final simplification64.6%

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

Alternative 6: 54.3% accurate, 1.9× speedup?

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

\\
\frac{-2}{x \cdot \left(\left(--1\right) - x\right)}
\end{array}
Derivation
  1. Initial program 66.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative66.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg66.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac266.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg66.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-66.0%

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

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified66.0%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. +-commutative66.0%

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

      \[\leadsto \color{blue}{\frac{-2 \cdot \left(-1 - x\right) - x \cdot 1}{x \cdot \left(-1 - x\right)}} + \frac{1}{x + -1} \]
    3. frac-add19.5%

      \[\leadsto \color{blue}{\frac{\left(-2 \cdot \left(-1 - x\right) - x \cdot 1\right) \cdot \left(x + -1\right) + \left(x \cdot \left(-1 - x\right)\right) \cdot 1}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)}} \]
    4. fma-define18.7%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(-2 \cdot \left(-1 - x\right) - x \cdot 1, x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
    5. *-rgt-identity18.7%

      \[\leadsto \frac{\mathsf{fma}\left(-2 \cdot \left(-1 - x\right) - \color{blue}{x}, x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
    6. fma-neg18.7%

      \[\leadsto \frac{\mathsf{fma}\left(\color{blue}{\mathsf{fma}\left(-2, -1 - x, -x\right)}, x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
  6. Applied egg-rr18.7%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\mathsf{fma}\left(-2, -1 - x, -x\right), x + -1, \left(x \cdot \left(-1 - x\right)\right) \cdot 1\right)}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)}} \]
  7. Taylor expanded in x around 0 99.4%

    \[\leadsto \frac{\color{blue}{-2}}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)} \]
  8. Taylor expanded in x around 0 50.1%

    \[\leadsto \frac{-2}{\color{blue}{\left(-1 \cdot x\right)} \cdot \left(x + -1\right)} \]
  9. Step-by-step derivation
    1. mul-1-neg50.1%

      \[\leadsto \frac{-2}{\color{blue}{\left(-x\right)} \cdot \left(x + -1\right)} \]
  10. Simplified50.1%

    \[\leadsto \frac{-2}{\color{blue}{\left(-x\right)} \cdot \left(x + -1\right)} \]
  11. Final simplification50.1%

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

Alternative 7: 54.3% accurate, 2.1× speedup?

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

\\
\frac{1}{x \cdot \left(1 - x\right)}
\end{array}
Derivation
  1. Initial program 66.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative66.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg66.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac266.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg66.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-66.0%

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

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified66.0%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 64.6%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1}{x}} \]
  6. Step-by-step derivation
    1. frac-2neg64.6%

      \[\leadsto \color{blue}{\frac{-1}{-\left(x + -1\right)}} + \frac{-1}{x} \]
    2. metadata-eval64.6%

      \[\leadsto \frac{\color{blue}{-1}}{-\left(x + -1\right)} + \frac{-1}{x} \]
    3. frac-2neg64.6%

      \[\leadsto \frac{-1}{-\left(x + -1\right)} + \color{blue}{\frac{--1}{-x}} \]
    4. metadata-eval64.6%

      \[\leadsto \frac{-1}{-\left(x + -1\right)} + \frac{\color{blue}{1}}{-x} \]
    5. frac-add64.6%

      \[\leadsto \color{blue}{\frac{-1 \cdot \left(-x\right) + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)}} \]
    6. add-sqr-sqrt26.2%

      \[\leadsto \frac{-1 \cdot \color{blue}{\left(\sqrt{-x} \cdot \sqrt{-x}\right)} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    7. sqrt-unprod10.9%

      \[\leadsto \frac{-1 \cdot \color{blue}{\sqrt{\left(-x\right) \cdot \left(-x\right)}} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    8. sqr-neg10.9%

      \[\leadsto \frac{-1 \cdot \sqrt{\color{blue}{x \cdot x}} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    9. sqrt-prod27.0%

      \[\leadsto \frac{-1 \cdot \color{blue}{\left(\sqrt{x} \cdot \sqrt{x}\right)} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    10. add-sqr-sqrt48.1%

      \[\leadsto \frac{-1 \cdot \color{blue}{x} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    11. neg-mul-148.1%

      \[\leadsto \frac{\color{blue}{\left(-x\right)} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    12. add-sqr-sqrt21.1%

      \[\leadsto \frac{\color{blue}{\sqrt{-x} \cdot \sqrt{-x}} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    13. sqrt-unprod8.5%

      \[\leadsto \frac{\color{blue}{\sqrt{\left(-x\right) \cdot \left(-x\right)}} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    14. sqr-neg8.5%

      \[\leadsto \frac{\sqrt{\color{blue}{x \cdot x}} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    15. sqrt-prod30.0%

      \[\leadsto \frac{\color{blue}{\sqrt{x} \cdot \sqrt{x}} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    16. add-sqr-sqrt64.6%

      \[\leadsto \frac{\color{blue}{x} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    17. add-sqr-sqrt30.4%

      \[\leadsto \frac{x + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \color{blue}{\left(\sqrt{-x} \cdot \sqrt{-x}\right)}} \]
    18. sqrt-unprod64.4%

      \[\leadsto \frac{x + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \color{blue}{\sqrt{\left(-x\right) \cdot \left(-x\right)}}} \]
    19. sqr-neg64.4%

      \[\leadsto \frac{x + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \sqrt{\color{blue}{x \cdot x}}} \]
    20. sqrt-prod34.0%

      \[\leadsto \frac{x + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \color{blue}{\left(\sqrt{x} \cdot \sqrt{x}\right)}} \]
    21. add-sqr-sqrt64.8%

      \[\leadsto \frac{x + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \color{blue}{x}} \]
  7. Applied egg-rr64.8%

    \[\leadsto \color{blue}{\frac{x + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot x}} \]
  8. Step-by-step derivation
    1. *-rgt-identity64.8%

      \[\leadsto \frac{x + \color{blue}{\left(-\left(x + -1\right)\right)}}{\left(-\left(x + -1\right)\right) \cdot x} \]
    2. sub-neg64.8%

      \[\leadsto \frac{\color{blue}{x - \left(x + -1\right)}}{\left(-\left(x + -1\right)\right) \cdot x} \]
    3. associate--r+50.1%

      \[\leadsto \frac{\color{blue}{\left(x - x\right) - -1}}{\left(-\left(x + -1\right)\right) \cdot x} \]
    4. +-inverses50.1%

      \[\leadsto \frac{\color{blue}{0} - -1}{\left(-\left(x + -1\right)\right) \cdot x} \]
    5. metadata-eval50.1%

      \[\leadsto \frac{\color{blue}{1}}{\left(-\left(x + -1\right)\right) \cdot x} \]
    6. *-commutative50.1%

      \[\leadsto \frac{1}{\color{blue}{x \cdot \left(-\left(x + -1\right)\right)}} \]
    7. distribute-rgt-neg-in50.1%

      \[\leadsto \frac{1}{\color{blue}{-x \cdot \left(x + -1\right)}} \]
    8. neg-mul-150.1%

      \[\leadsto \frac{1}{\color{blue}{-1 \cdot \left(x \cdot \left(x + -1\right)\right)}} \]
    9. *-commutative50.1%

      \[\leadsto \frac{1}{\color{blue}{\left(x \cdot \left(x + -1\right)\right) \cdot -1}} \]
    10. associate-*l*50.1%

      \[\leadsto \frac{1}{\color{blue}{x \cdot \left(\left(x + -1\right) \cdot -1\right)}} \]
    11. *-commutative50.1%

      \[\leadsto \frac{1}{x \cdot \color{blue}{\left(-1 \cdot \left(x + -1\right)\right)}} \]
    12. neg-mul-150.1%

      \[\leadsto \frac{1}{x \cdot \color{blue}{\left(-\left(x + -1\right)\right)}} \]
    13. neg-sub050.1%

      \[\leadsto \frac{1}{x \cdot \color{blue}{\left(0 - \left(x + -1\right)\right)}} \]
    14. +-commutative50.1%

      \[\leadsto \frac{1}{x \cdot \left(0 - \color{blue}{\left(-1 + x\right)}\right)} \]
    15. associate--r+50.1%

      \[\leadsto \frac{1}{x \cdot \color{blue}{\left(\left(0 - -1\right) - x\right)}} \]
    16. metadata-eval50.1%

      \[\leadsto \frac{1}{x \cdot \left(\color{blue}{1} - x\right)} \]
  9. Simplified50.1%

    \[\leadsto \color{blue}{\frac{1}{x \cdot \left(1 - x\right)}} \]
  10. Final simplification50.1%

    \[\leadsto \frac{1}{x \cdot \left(1 - x\right)} \]
  11. 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 66.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative66.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg66.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac266.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg66.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-66.0%

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

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified66.0%

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

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

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

Alternative 9: 5.1% accurate, 5.0× speedup?

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

\\
\frac{-1}{x}
\end{array}
Derivation
  1. Initial program 66.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative66.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg66.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac266.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg66.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-66.0%

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

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified66.0%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 64.6%

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

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

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

Alternative 10: 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 66.0%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. +-commutative66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)} \]
    2. associate-+r-65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) - \frac{2}{x}} \]
    3. sub-neg65.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) + \left(-\frac{2}{x}\right)} \]
    4. remove-double-neg65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(-\left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    5. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{\left(0 - \left(-x\right)\right)} + 1}\right) + \left(-\frac{2}{x}\right) \]
    6. associate-+l-65.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{0 - \left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    7. neg-sub065.9%

      \[\leadsto \left(\frac{1}{x - 1} + \frac{1}{\color{blue}{-\left(\left(-x\right) - 1\right)}}\right) + \left(-\frac{2}{x}\right) \]
    8. distribute-neg-frac265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \color{blue}{\left(-\frac{1}{\left(-x\right) - 1}\right)}\right) + \left(-\frac{2}{x}\right) \]
    9. distribute-frac-neg265.9%

      \[\leadsto \left(\frac{1}{x - 1} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) + \color{blue}{\frac{2}{-x}} \]
    10. associate-+r+66.0%

      \[\leadsto \color{blue}{\frac{1}{x - 1} + \left(\left(-\frac{1}{\left(-x\right) - 1}\right) + \frac{2}{-x}\right)} \]
    11. +-commutative66.0%

      \[\leadsto \frac{1}{x - 1} + \color{blue}{\left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right)} \]
    12. remove-double-neg66.0%

      \[\leadsto \color{blue}{\left(-\left(-\frac{1}{x - 1}\right)\right)} + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    13. distribute-neg-frac266.0%

      \[\leadsto \left(-\color{blue}{\frac{1}{-\left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    14. sub0-neg66.0%

      \[\leadsto \left(-\frac{1}{\color{blue}{0 - \left(x - 1\right)}}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
    15. associate-+l-66.0%

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

      \[\leadsto \left(-\frac{1}{\color{blue}{\left(-x\right)} + 1}\right) + \left(\frac{2}{-x} + \left(-\frac{1}{\left(-x\right) - 1}\right)\right) \]
  3. Simplified66.0%

    \[\leadsto \color{blue}{\frac{1}{x + -1} + \left(\frac{-2}{x} - \frac{1}{-1 - x}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 64.6%

    \[\leadsto \frac{1}{x + -1} + \color{blue}{\frac{-1}{x}} \]
  6. Step-by-step derivation
    1. frac-2neg64.6%

      \[\leadsto \color{blue}{\frac{-1}{-\left(x + -1\right)}} + \frac{-1}{x} \]
    2. metadata-eval64.6%

      \[\leadsto \frac{\color{blue}{-1}}{-\left(x + -1\right)} + \frac{-1}{x} \]
    3. frac-2neg64.6%

      \[\leadsto \frac{-1}{-\left(x + -1\right)} + \color{blue}{\frac{--1}{-x}} \]
    4. metadata-eval64.6%

      \[\leadsto \frac{-1}{-\left(x + -1\right)} + \frac{\color{blue}{1}}{-x} \]
    5. frac-add64.6%

      \[\leadsto \color{blue}{\frac{-1 \cdot \left(-x\right) + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)}} \]
    6. add-sqr-sqrt26.2%

      \[\leadsto \frac{-1 \cdot \color{blue}{\left(\sqrt{-x} \cdot \sqrt{-x}\right)} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    7. sqrt-unprod10.9%

      \[\leadsto \frac{-1 \cdot \color{blue}{\sqrt{\left(-x\right) \cdot \left(-x\right)}} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    8. sqr-neg10.9%

      \[\leadsto \frac{-1 \cdot \sqrt{\color{blue}{x \cdot x}} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    9. sqrt-prod27.0%

      \[\leadsto \frac{-1 \cdot \color{blue}{\left(\sqrt{x} \cdot \sqrt{x}\right)} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    10. add-sqr-sqrt48.1%

      \[\leadsto \frac{-1 \cdot \color{blue}{x} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    11. neg-mul-148.1%

      \[\leadsto \frac{\color{blue}{\left(-x\right)} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    12. add-sqr-sqrt21.1%

      \[\leadsto \frac{\color{blue}{\sqrt{-x} \cdot \sqrt{-x}} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    13. sqrt-unprod8.5%

      \[\leadsto \frac{\color{blue}{\sqrt{\left(-x\right) \cdot \left(-x\right)}} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    14. sqr-neg8.5%

      \[\leadsto \frac{\sqrt{\color{blue}{x \cdot x}} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    15. sqrt-prod30.0%

      \[\leadsto \frac{\color{blue}{\sqrt{x} \cdot \sqrt{x}} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    16. add-sqr-sqrt64.6%

      \[\leadsto \frac{\color{blue}{x} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \left(-x\right)} \]
    17. add-sqr-sqrt30.4%

      \[\leadsto \frac{x + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \color{blue}{\left(\sqrt{-x} \cdot \sqrt{-x}\right)}} \]
    18. sqrt-unprod64.4%

      \[\leadsto \frac{x + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \color{blue}{\sqrt{\left(-x\right) \cdot \left(-x\right)}}} \]
    19. sqr-neg64.4%

      \[\leadsto \frac{x + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \sqrt{\color{blue}{x \cdot x}}} \]
    20. sqrt-prod34.0%

      \[\leadsto \frac{x + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \color{blue}{\left(\sqrt{x} \cdot \sqrt{x}\right)}} \]
    21. add-sqr-sqrt64.8%

      \[\leadsto \frac{x + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \color{blue}{x}} \]
  7. Applied egg-rr64.8%

    \[\leadsto \color{blue}{\frac{x + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot x}} \]
  8. Step-by-step derivation
    1. *-rgt-identity64.8%

      \[\leadsto \frac{x + \color{blue}{\left(-\left(x + -1\right)\right)}}{\left(-\left(x + -1\right)\right) \cdot x} \]
    2. sub-neg64.8%

      \[\leadsto \frac{\color{blue}{x - \left(x + -1\right)}}{\left(-\left(x + -1\right)\right) \cdot x} \]
    3. associate--r+50.1%

      \[\leadsto \frac{\color{blue}{\left(x - x\right) - -1}}{\left(-\left(x + -1\right)\right) \cdot x} \]
    4. +-inverses50.1%

      \[\leadsto \frac{\color{blue}{0} - -1}{\left(-\left(x + -1\right)\right) \cdot x} \]
    5. metadata-eval50.1%

      \[\leadsto \frac{\color{blue}{1}}{\left(-\left(x + -1\right)\right) \cdot x} \]
    6. *-commutative50.1%

      \[\leadsto \frac{1}{\color{blue}{x \cdot \left(-\left(x + -1\right)\right)}} \]
    7. distribute-rgt-neg-in50.1%

      \[\leadsto \frac{1}{\color{blue}{-x \cdot \left(x + -1\right)}} \]
    8. neg-mul-150.1%

      \[\leadsto \frac{1}{\color{blue}{-1 \cdot \left(x \cdot \left(x + -1\right)\right)}} \]
    9. *-commutative50.1%

      \[\leadsto \frac{1}{\color{blue}{\left(x \cdot \left(x + -1\right)\right) \cdot -1}} \]
    10. associate-*l*50.1%

      \[\leadsto \frac{1}{\color{blue}{x \cdot \left(\left(x + -1\right) \cdot -1\right)}} \]
    11. *-commutative50.1%

      \[\leadsto \frac{1}{x \cdot \color{blue}{\left(-1 \cdot \left(x + -1\right)\right)}} \]
    12. neg-mul-150.1%

      \[\leadsto \frac{1}{x \cdot \color{blue}{\left(-\left(x + -1\right)\right)}} \]
    13. neg-sub050.1%

      \[\leadsto \frac{1}{x \cdot \color{blue}{\left(0 - \left(x + -1\right)\right)}} \]
    14. +-commutative50.1%

      \[\leadsto \frac{1}{x \cdot \left(0 - \color{blue}{\left(-1 + x\right)}\right)} \]
    15. associate--r+50.1%

      \[\leadsto \frac{1}{x \cdot \color{blue}{\left(\left(0 - -1\right) - x\right)}} \]
    16. metadata-eval50.1%

      \[\leadsto \frac{1}{x \cdot \left(\color{blue}{1} - x\right)} \]
  9. Simplified50.1%

    \[\leadsto \color{blue}{\frac{1}{x \cdot \left(1 - x\right)}} \]
  10. Taylor expanded in x around 0 6.3%

    \[\leadsto \color{blue}{\frac{1}{x}} \]
  11. Final simplification6.3%

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

Developer target: 99.3% accurate, 1.7× speedup?

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

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

Reproduce

?
herbie shell --seed 2024073 
(FPCore (x)
  :name "3frac (problem 3.3.3)"
  :precision binary64
  :pre (> (fabs x) 1.0)

  :alt
  (/ 2.0 (* x (- (* x x) 1.0)))

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