3frac (problem 3.3.3)

Percentage Accurate: 68.5% → 99.2%
Time: 9.5s
Alternatives: 7
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 7 alternatives:

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

Initial Program: 68.5% 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: 99.2% accurate, 0.1× speedup?

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

\\
\frac{2}{{x}^{3} - x}
\end{array}
Derivation
  1. Initial program 69.2%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. sub-neg69.2%

      \[\leadsto \color{blue}{\left(\frac{1}{x + 1} + \left(-\frac{2}{x}\right)\right)} + \frac{1}{x - 1} \]
    2. distribute-neg-frac69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{-2}{x}}\right) + \frac{1}{x - 1} \]
    3. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{-2}}{x}\right) + \frac{1}{x - 1} \]
    4. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{\frac{2}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    5. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\frac{2}{\color{blue}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    6. associate-/r*69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{2}{\left(-1\right) \cdot x}}\right) + \frac{1}{x - 1} \]
    7. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-1} \cdot x}\right) + \frac{1}{x - 1} \]
    8. neg-mul-169.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-x}}\right) + \frac{1}{x - 1} \]
    9. +-commutative69.2%

      \[\leadsto \color{blue}{\left(\frac{2}{-x} + \frac{1}{x + 1}\right)} + \frac{1}{x - 1} \]
    10. associate-+l+69.2%

      \[\leadsto \color{blue}{\frac{2}{-x} + \left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    11. +-commutative69.2%

      \[\leadsto \frac{2}{-x} + \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right)} \]
    12. neg-mul-169.2%

      \[\leadsto \frac{2}{\color{blue}{-1 \cdot x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    13. metadata-eval69.2%

      \[\leadsto \frac{2}{\color{blue}{\left(-1\right)} \cdot x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    14. associate-/r*69.2%

      \[\leadsto \color{blue}{\frac{\frac{2}{-1}}{x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    15. metadata-eval69.2%

      \[\leadsto \frac{\frac{2}{\color{blue}{-1}}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    16. metadata-eval69.2%

      \[\leadsto \frac{\color{blue}{-2}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    17. +-commutative69.2%

      \[\leadsto \frac{-2}{x} + \color{blue}{\left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    18. +-commutative69.2%

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

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{\color{blue}{x + \left(-1\right)}}\right) \]
    20. metadata-eval69.2%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + \color{blue}{-1}}\right) \]
  3. Simplified69.2%

    \[\leadsto \color{blue}{\frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + -1}\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. +-commutative69.2%

      \[\leadsto \color{blue}{\left(\frac{1}{1 + x} + \frac{1}{x + -1}\right) + \frac{-2}{x}} \]
    2. frac-add21.0%

      \[\leadsto \color{blue}{\frac{1 \cdot \left(x + -1\right) + \left(1 + x\right) \cdot 1}{\left(1 + x\right) \cdot \left(x + -1\right)}} + \frac{-2}{x} \]
    3. frac-add20.6%

      \[\leadsto \color{blue}{\frac{\left(1 \cdot \left(x + -1\right) + \left(1 + x\right) \cdot 1\right) \cdot x + \left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot x}} \]
    4. *-un-lft-identity20.6%

      \[\leadsto \frac{\left(\color{blue}{\left(x + -1\right)} + \left(1 + x\right) \cdot 1\right) \cdot x + \left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot x} \]
    5. *-rgt-identity20.6%

      \[\leadsto \frac{\left(\left(x + -1\right) + \color{blue}{\left(1 + x\right)}\right) \cdot x + \left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot x} \]
    6. +-commutative20.6%

      \[\leadsto \frac{\color{blue}{\left(\left(1 + x\right) + \left(x + -1\right)\right)} \cdot x + \left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot x} \]
    7. +-commutative20.6%

      \[\leadsto \frac{\left(\color{blue}{\left(x + 1\right)} + \left(x + -1\right)\right) \cdot x + \left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot x} \]
    8. +-commutative20.6%

      \[\leadsto \frac{\left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot x + \left(\color{blue}{\left(x + 1\right)} \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot x} \]
    9. +-commutative20.6%

      \[\leadsto \frac{\left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot x + \left(\left(x + 1\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\color{blue}{\left(x + 1\right)} \cdot \left(x + -1\right)\right) \cdot x} \]
  6. Applied egg-rr20.6%

    \[\leadsto \color{blue}{\frac{\left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot x + \left(\left(x + 1\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(x + 1\right) \cdot \left(x + -1\right)\right) \cdot x}} \]
  7. Taylor expanded in x around 0 99.6%

    \[\leadsto \frac{\color{blue}{2}}{\left(\left(x + 1\right) \cdot \left(x + -1\right)\right) \cdot x} \]
  8. Step-by-step derivation
    1. expm1-log1p-u99.6%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{2}{\left(\left(x + 1\right) \cdot \left(x + -1\right)\right) \cdot x}\right)\right)} \]
    2. expm1-udef68.8%

      \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\frac{2}{\left(\left(x + 1\right) \cdot \left(x + -1\right)\right) \cdot x}\right)} - 1} \]
    3. *-commutative68.8%

      \[\leadsto e^{\mathsf{log1p}\left(\frac{2}{\color{blue}{x \cdot \left(\left(x + 1\right) \cdot \left(x + -1\right)\right)}}\right)} - 1 \]
    4. metadata-eval68.8%

      \[\leadsto e^{\mathsf{log1p}\left(\frac{2}{x \cdot \left(\left(x + 1\right) \cdot \left(x + \color{blue}{\left(-1\right)}\right)\right)}\right)} - 1 \]
    5. sub-neg68.8%

      \[\leadsto e^{\mathsf{log1p}\left(\frac{2}{x \cdot \left(\left(x + 1\right) \cdot \color{blue}{\left(x - 1\right)}\right)}\right)} - 1 \]
    6. difference-of-sqr-168.8%

      \[\leadsto e^{\mathsf{log1p}\left(\frac{2}{x \cdot \color{blue}{\left(x \cdot x - 1\right)}}\right)} - 1 \]
    7. distribute-rgt-out--68.8%

      \[\leadsto e^{\mathsf{log1p}\left(\frac{2}{\color{blue}{\left(x \cdot x\right) \cdot x - 1 \cdot x}}\right)} - 1 \]
    8. unpow368.8%

      \[\leadsto e^{\mathsf{log1p}\left(\frac{2}{\color{blue}{{x}^{3}} - 1 \cdot x}\right)} - 1 \]
    9. *-un-lft-identity68.8%

      \[\leadsto e^{\mathsf{log1p}\left(\frac{2}{{x}^{3} - \color{blue}{x}}\right)} - 1 \]
  9. Applied egg-rr68.8%

    \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\frac{2}{{x}^{3} - x}\right)} - 1} \]
  10. Step-by-step derivation
    1. expm1-def99.7%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{2}{{x}^{3} - x}\right)\right)} \]
    2. expm1-log1p99.7%

      \[\leadsto \color{blue}{\frac{2}{{x}^{3} - x}} \]
  11. Simplified99.7%

    \[\leadsto \color{blue}{\frac{2}{{x}^{3} - x}} \]
  12. Final simplification99.7%

    \[\leadsto \frac{2}{{x}^{3} - x} \]
  13. Add Preprocessing

Alternative 2: 99.2% accurate, 1.4× speedup?

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

\\
\frac{2}{x \cdot \left(\left(x + 1\right) \cdot \left(x + -1\right)\right)}
\end{array}
Derivation
  1. Initial program 69.2%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. sub-neg69.2%

      \[\leadsto \color{blue}{\left(\frac{1}{x + 1} + \left(-\frac{2}{x}\right)\right)} + \frac{1}{x - 1} \]
    2. distribute-neg-frac69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{-2}{x}}\right) + \frac{1}{x - 1} \]
    3. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{-2}}{x}\right) + \frac{1}{x - 1} \]
    4. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{\frac{2}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    5. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\frac{2}{\color{blue}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    6. associate-/r*69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{2}{\left(-1\right) \cdot x}}\right) + \frac{1}{x - 1} \]
    7. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-1} \cdot x}\right) + \frac{1}{x - 1} \]
    8. neg-mul-169.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-x}}\right) + \frac{1}{x - 1} \]
    9. +-commutative69.2%

      \[\leadsto \color{blue}{\left(\frac{2}{-x} + \frac{1}{x + 1}\right)} + \frac{1}{x - 1} \]
    10. associate-+l+69.2%

      \[\leadsto \color{blue}{\frac{2}{-x} + \left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    11. +-commutative69.2%

      \[\leadsto \frac{2}{-x} + \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right)} \]
    12. neg-mul-169.2%

      \[\leadsto \frac{2}{\color{blue}{-1 \cdot x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    13. metadata-eval69.2%

      \[\leadsto \frac{2}{\color{blue}{\left(-1\right)} \cdot x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    14. associate-/r*69.2%

      \[\leadsto \color{blue}{\frac{\frac{2}{-1}}{x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    15. metadata-eval69.2%

      \[\leadsto \frac{\frac{2}{\color{blue}{-1}}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    16. metadata-eval69.2%

      \[\leadsto \frac{\color{blue}{-2}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    17. +-commutative69.2%

      \[\leadsto \frac{-2}{x} + \color{blue}{\left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    18. +-commutative69.2%

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

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{\color{blue}{x + \left(-1\right)}}\right) \]
    20. metadata-eval69.2%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + \color{blue}{-1}}\right) \]
  3. Simplified69.2%

    \[\leadsto \color{blue}{\frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + -1}\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. +-commutative69.2%

      \[\leadsto \color{blue}{\left(\frac{1}{1 + x} + \frac{1}{x + -1}\right) + \frac{-2}{x}} \]
    2. frac-add21.0%

      \[\leadsto \color{blue}{\frac{1 \cdot \left(x + -1\right) + \left(1 + x\right) \cdot 1}{\left(1 + x\right) \cdot \left(x + -1\right)}} + \frac{-2}{x} \]
    3. frac-add20.6%

      \[\leadsto \color{blue}{\frac{\left(1 \cdot \left(x + -1\right) + \left(1 + x\right) \cdot 1\right) \cdot x + \left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot x}} \]
    4. *-un-lft-identity20.6%

      \[\leadsto \frac{\left(\color{blue}{\left(x + -1\right)} + \left(1 + x\right) \cdot 1\right) \cdot x + \left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot x} \]
    5. *-rgt-identity20.6%

      \[\leadsto \frac{\left(\left(x + -1\right) + \color{blue}{\left(1 + x\right)}\right) \cdot x + \left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot x} \]
    6. +-commutative20.6%

      \[\leadsto \frac{\color{blue}{\left(\left(1 + x\right) + \left(x + -1\right)\right)} \cdot x + \left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot x} \]
    7. +-commutative20.6%

      \[\leadsto \frac{\left(\color{blue}{\left(x + 1\right)} + \left(x + -1\right)\right) \cdot x + \left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot x} \]
    8. +-commutative20.6%

      \[\leadsto \frac{\left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot x + \left(\color{blue}{\left(x + 1\right)} \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot x} \]
    9. +-commutative20.6%

      \[\leadsto \frac{\left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot x + \left(\left(x + 1\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\color{blue}{\left(x + 1\right)} \cdot \left(x + -1\right)\right) \cdot x} \]
  6. Applied egg-rr20.6%

    \[\leadsto \color{blue}{\frac{\left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot x + \left(\left(x + 1\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(x + 1\right) \cdot \left(x + -1\right)\right) \cdot x}} \]
  7. Taylor expanded in x around 0 99.6%

    \[\leadsto \frac{\color{blue}{2}}{\left(\left(x + 1\right) \cdot \left(x + -1\right)\right) \cdot x} \]
  8. Final simplification99.6%

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

Alternative 3: 99.2% accurate, 1.4× speedup?

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

\\
\frac{2}{\left(x + 1\right) \cdot \left(x \cdot \left(x + -1\right)\right)}
\end{array}
Derivation
  1. Initial program 69.2%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. sub-neg69.2%

      \[\leadsto \color{blue}{\left(\frac{1}{x + 1} + \left(-\frac{2}{x}\right)\right)} + \frac{1}{x - 1} \]
    2. distribute-neg-frac69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{-2}{x}}\right) + \frac{1}{x - 1} \]
    3. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{-2}}{x}\right) + \frac{1}{x - 1} \]
    4. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{\frac{2}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    5. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\frac{2}{\color{blue}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    6. associate-/r*69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{2}{\left(-1\right) \cdot x}}\right) + \frac{1}{x - 1} \]
    7. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-1} \cdot x}\right) + \frac{1}{x - 1} \]
    8. neg-mul-169.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-x}}\right) + \frac{1}{x - 1} \]
    9. +-commutative69.2%

      \[\leadsto \color{blue}{\left(\frac{2}{-x} + \frac{1}{x + 1}\right)} + \frac{1}{x - 1} \]
    10. associate-+l+69.2%

      \[\leadsto \color{blue}{\frac{2}{-x} + \left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    11. +-commutative69.2%

      \[\leadsto \frac{2}{-x} + \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right)} \]
    12. neg-mul-169.2%

      \[\leadsto \frac{2}{\color{blue}{-1 \cdot x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    13. metadata-eval69.2%

      \[\leadsto \frac{2}{\color{blue}{\left(-1\right)} \cdot x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    14. associate-/r*69.2%

      \[\leadsto \color{blue}{\frac{\frac{2}{-1}}{x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    15. metadata-eval69.2%

      \[\leadsto \frac{\frac{2}{\color{blue}{-1}}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    16. metadata-eval69.2%

      \[\leadsto \frac{\color{blue}{-2}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    17. +-commutative69.2%

      \[\leadsto \frac{-2}{x} + \color{blue}{\left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    18. +-commutative69.2%

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

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{\color{blue}{x + \left(-1\right)}}\right) \]
    20. metadata-eval69.2%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + \color{blue}{-1}}\right) \]
  3. Simplified69.2%

    \[\leadsto \color{blue}{\frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + -1}\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. +-commutative69.2%

      \[\leadsto \color{blue}{\left(\frac{1}{1 + x} + \frac{1}{x + -1}\right) + \frac{-2}{x}} \]
    2. frac-add21.0%

      \[\leadsto \color{blue}{\frac{1 \cdot \left(x + -1\right) + \left(1 + x\right) \cdot 1}{\left(1 + x\right) \cdot \left(x + -1\right)}} + \frac{-2}{x} \]
    3. frac-add20.6%

      \[\leadsto \color{blue}{\frac{\left(1 \cdot \left(x + -1\right) + \left(1 + x\right) \cdot 1\right) \cdot x + \left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot x}} \]
    4. *-un-lft-identity20.6%

      \[\leadsto \frac{\left(\color{blue}{\left(x + -1\right)} + \left(1 + x\right) \cdot 1\right) \cdot x + \left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot x} \]
    5. *-rgt-identity20.6%

      \[\leadsto \frac{\left(\left(x + -1\right) + \color{blue}{\left(1 + x\right)}\right) \cdot x + \left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot x} \]
    6. +-commutative20.6%

      \[\leadsto \frac{\color{blue}{\left(\left(1 + x\right) + \left(x + -1\right)\right)} \cdot x + \left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot x} \]
    7. +-commutative20.6%

      \[\leadsto \frac{\left(\color{blue}{\left(x + 1\right)} + \left(x + -1\right)\right) \cdot x + \left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot x} \]
    8. +-commutative20.6%

      \[\leadsto \frac{\left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot x + \left(\color{blue}{\left(x + 1\right)} \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(1 + x\right) \cdot \left(x + -1\right)\right) \cdot x} \]
    9. +-commutative20.6%

      \[\leadsto \frac{\left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot x + \left(\left(x + 1\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\color{blue}{\left(x + 1\right)} \cdot \left(x + -1\right)\right) \cdot x} \]
  6. Applied egg-rr20.6%

    \[\leadsto \color{blue}{\frac{\left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot x + \left(\left(x + 1\right) \cdot \left(x + -1\right)\right) \cdot -2}{\left(\left(x + 1\right) \cdot \left(x + -1\right)\right) \cdot x}} \]
  7. Taylor expanded in x around 0 99.6%

    \[\leadsto \frac{\color{blue}{2}}{\left(\left(x + 1\right) \cdot \left(x + -1\right)\right) \cdot x} \]
  8. Step-by-step derivation
    1. expm1-log1p-u48.9%

      \[\leadsto \frac{2}{\color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\left(\left(x + 1\right) \cdot \left(x + -1\right)\right) \cdot x\right)\right)}} \]
    2. expm1-udef48.9%

      \[\leadsto \frac{2}{\color{blue}{e^{\mathsf{log1p}\left(\left(\left(x + 1\right) \cdot \left(x + -1\right)\right) \cdot x\right)} - 1}} \]
    3. associate-*l*48.9%

      \[\leadsto \frac{2}{e^{\mathsf{log1p}\left(\color{blue}{\left(x + 1\right) \cdot \left(\left(x + -1\right) \cdot x\right)}\right)} - 1} \]
    4. +-commutative48.9%

      \[\leadsto \frac{2}{e^{\mathsf{log1p}\left(\color{blue}{\left(1 + x\right)} \cdot \left(\left(x + -1\right) \cdot x\right)\right)} - 1} \]
  9. Applied egg-rr48.9%

    \[\leadsto \frac{2}{\color{blue}{e^{\mathsf{log1p}\left(\left(1 + x\right) \cdot \left(\left(x + -1\right) \cdot x\right)\right)} - 1}} \]
  10. Step-by-step derivation
    1. expm1-def48.9%

      \[\leadsto \frac{2}{\color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\left(1 + x\right) \cdot \left(\left(x + -1\right) \cdot x\right)\right)\right)}} \]
    2. expm1-log1p99.6%

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

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

      \[\leadsto \frac{2}{\left(x + 1\right) \cdot \color{blue}{\left(x \cdot \left(x + -1\right)\right)}} \]
  11. Simplified99.6%

    \[\leadsto \frac{2}{\color{blue}{\left(x + 1\right) \cdot \left(x \cdot \left(x + -1\right)\right)}} \]
  12. Final simplification99.6%

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

Alternative 4: 67.0% accurate, 2.1× speedup?

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

\\
\frac{-2}{x} + \frac{2}{x}
\end{array}
Derivation
  1. Initial program 69.2%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. sub-neg69.2%

      \[\leadsto \color{blue}{\left(\frac{1}{x + 1} + \left(-\frac{2}{x}\right)\right)} + \frac{1}{x - 1} \]
    2. distribute-neg-frac69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{-2}{x}}\right) + \frac{1}{x - 1} \]
    3. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{-2}}{x}\right) + \frac{1}{x - 1} \]
    4. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{\frac{2}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    5. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\frac{2}{\color{blue}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    6. associate-/r*69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{2}{\left(-1\right) \cdot x}}\right) + \frac{1}{x - 1} \]
    7. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-1} \cdot x}\right) + \frac{1}{x - 1} \]
    8. neg-mul-169.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-x}}\right) + \frac{1}{x - 1} \]
    9. +-commutative69.2%

      \[\leadsto \color{blue}{\left(\frac{2}{-x} + \frac{1}{x + 1}\right)} + \frac{1}{x - 1} \]
    10. associate-+l+69.2%

      \[\leadsto \color{blue}{\frac{2}{-x} + \left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    11. +-commutative69.2%

      \[\leadsto \frac{2}{-x} + \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right)} \]
    12. neg-mul-169.2%

      \[\leadsto \frac{2}{\color{blue}{-1 \cdot x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    13. metadata-eval69.2%

      \[\leadsto \frac{2}{\color{blue}{\left(-1\right)} \cdot x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    14. associate-/r*69.2%

      \[\leadsto \color{blue}{\frac{\frac{2}{-1}}{x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    15. metadata-eval69.2%

      \[\leadsto \frac{\frac{2}{\color{blue}{-1}}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    16. metadata-eval69.2%

      \[\leadsto \frac{\color{blue}{-2}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    17. +-commutative69.2%

      \[\leadsto \frac{-2}{x} + \color{blue}{\left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    18. +-commutative69.2%

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

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{\color{blue}{x + \left(-1\right)}}\right) \]
    20. metadata-eval69.2%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + \color{blue}{-1}}\right) \]
  3. Simplified69.2%

    \[\leadsto \color{blue}{\frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + -1}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 67.2%

    \[\leadsto \frac{-2}{x} + \color{blue}{\frac{2}{x}} \]
  6. Final simplification67.2%

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

Alternative 5: 5.0% accurate, 5.0× speedup?

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

\\
\frac{-2}{x}
\end{array}
Derivation
  1. Initial program 69.2%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. sub-neg69.2%

      \[\leadsto \color{blue}{\left(\frac{1}{x + 1} + \left(-\frac{2}{x}\right)\right)} + \frac{1}{x - 1} \]
    2. distribute-neg-frac69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{-2}{x}}\right) + \frac{1}{x - 1} \]
    3. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{-2}}{x}\right) + \frac{1}{x - 1} \]
    4. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{\frac{2}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    5. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\frac{2}{\color{blue}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    6. associate-/r*69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{2}{\left(-1\right) \cdot x}}\right) + \frac{1}{x - 1} \]
    7. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-1} \cdot x}\right) + \frac{1}{x - 1} \]
    8. neg-mul-169.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-x}}\right) + \frac{1}{x - 1} \]
    9. +-commutative69.2%

      \[\leadsto \color{blue}{\left(\frac{2}{-x} + \frac{1}{x + 1}\right)} + \frac{1}{x - 1} \]
    10. associate-+l+69.2%

      \[\leadsto \color{blue}{\frac{2}{-x} + \left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    11. +-commutative69.2%

      \[\leadsto \frac{2}{-x} + \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right)} \]
    12. neg-mul-169.2%

      \[\leadsto \frac{2}{\color{blue}{-1 \cdot x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    13. metadata-eval69.2%

      \[\leadsto \frac{2}{\color{blue}{\left(-1\right)} \cdot x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    14. associate-/r*69.2%

      \[\leadsto \color{blue}{\frac{\frac{2}{-1}}{x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    15. metadata-eval69.2%

      \[\leadsto \frac{\frac{2}{\color{blue}{-1}}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    16. metadata-eval69.2%

      \[\leadsto \frac{\color{blue}{-2}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    17. +-commutative69.2%

      \[\leadsto \frac{-2}{x} + \color{blue}{\left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    18. +-commutative69.2%

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

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{\color{blue}{x + \left(-1\right)}}\right) \]
    20. metadata-eval69.2%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + \color{blue}{-1}}\right) \]
  3. Simplified69.2%

    \[\leadsto \color{blue}{\frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + -1}\right)} \]
  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 6: 3.3% accurate, 15.0× speedup?

\[\begin{array}{l} \\ -9 \end{array} \]
(FPCore (x) :precision binary64 -9.0)
double code(double x) {
	return -9.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = -9.0d0
end function
public static double code(double x) {
	return -9.0;
}
def code(x):
	return -9.0
function code(x)
	return -9.0
end
function tmp = code(x)
	tmp = -9.0;
end
code[x_] := -9.0
\begin{array}{l}

\\
-9
\end{array}
Derivation
  1. Initial program 69.2%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. sub-neg69.2%

      \[\leadsto \color{blue}{\left(\frac{1}{x + 1} + \left(-\frac{2}{x}\right)\right)} + \frac{1}{x - 1} \]
    2. distribute-neg-frac69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{-2}{x}}\right) + \frac{1}{x - 1} \]
    3. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{-2}}{x}\right) + \frac{1}{x - 1} \]
    4. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{\frac{2}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    5. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\frac{2}{\color{blue}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    6. associate-/r*69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{2}{\left(-1\right) \cdot x}}\right) + \frac{1}{x - 1} \]
    7. metadata-eval69.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-1} \cdot x}\right) + \frac{1}{x - 1} \]
    8. neg-mul-169.2%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-x}}\right) + \frac{1}{x - 1} \]
    9. +-commutative69.2%

      \[\leadsto \color{blue}{\left(\frac{2}{-x} + \frac{1}{x + 1}\right)} + \frac{1}{x - 1} \]
    10. associate-+l+69.2%

      \[\leadsto \color{blue}{\frac{2}{-x} + \left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    11. +-commutative69.2%

      \[\leadsto \frac{2}{-x} + \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right)} \]
    12. neg-mul-169.2%

      \[\leadsto \frac{2}{\color{blue}{-1 \cdot x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    13. metadata-eval69.2%

      \[\leadsto \frac{2}{\color{blue}{\left(-1\right)} \cdot x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    14. associate-/r*69.2%

      \[\leadsto \color{blue}{\frac{\frac{2}{-1}}{x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    15. metadata-eval69.2%

      \[\leadsto \frac{\frac{2}{\color{blue}{-1}}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    16. metadata-eval69.2%

      \[\leadsto \frac{\color{blue}{-2}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    17. +-commutative69.2%

      \[\leadsto \frac{-2}{x} + \color{blue}{\left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    18. +-commutative69.2%

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

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{\color{blue}{x + \left(-1\right)}}\right) \]
    20. metadata-eval69.2%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + \color{blue}{-1}}\right) \]
  3. Simplified69.2%

    \[\leadsto \color{blue}{\frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + -1}\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. frac-add21.0%

      \[\leadsto \frac{-2}{x} + \color{blue}{\frac{1 \cdot \left(x + -1\right) + \left(1 + x\right) \cdot 1}{\left(1 + x\right) \cdot \left(x + -1\right)}} \]
    2. div-inv16.5%

      \[\leadsto \frac{-2}{x} + \color{blue}{\left(1 \cdot \left(x + -1\right) + \left(1 + x\right) \cdot 1\right) \cdot \frac{1}{\left(1 + x\right) \cdot \left(x + -1\right)}} \]
    3. *-un-lft-identity16.5%

      \[\leadsto \frac{-2}{x} + \left(\color{blue}{\left(x + -1\right)} + \left(1 + x\right) \cdot 1\right) \cdot \frac{1}{\left(1 + x\right) \cdot \left(x + -1\right)} \]
    4. *-rgt-identity16.5%

      \[\leadsto \frac{-2}{x} + \left(\left(x + -1\right) + \color{blue}{\left(1 + x\right)}\right) \cdot \frac{1}{\left(1 + x\right) \cdot \left(x + -1\right)} \]
    5. +-commutative16.5%

      \[\leadsto \frac{-2}{x} + \color{blue}{\left(\left(1 + x\right) + \left(x + -1\right)\right)} \cdot \frac{1}{\left(1 + x\right) \cdot \left(x + -1\right)} \]
    6. +-commutative16.5%

      \[\leadsto \frac{-2}{x} + \left(\color{blue}{\left(x + 1\right)} + \left(x + -1\right)\right) \cdot \frac{1}{\left(1 + x\right) \cdot \left(x + -1\right)} \]
    7. metadata-eval16.5%

      \[\leadsto \frac{-2}{x} + \left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot \frac{\color{blue}{1 \cdot 1}}{\left(1 + x\right) \cdot \left(x + -1\right)} \]
    8. frac-times19.0%

      \[\leadsto \frac{-2}{x} + \left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot \color{blue}{\left(\frac{1}{1 + x} \cdot \frac{1}{x + -1}\right)} \]
    9. clear-num19.0%

      \[\leadsto \frac{-2}{x} + \left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot \left(\frac{1}{1 + x} \cdot \color{blue}{\frac{1}{\frac{x + -1}{1}}}\right) \]
    10. frac-times16.5%

      \[\leadsto \frac{-2}{x} + \left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot \color{blue}{\frac{1 \cdot 1}{\left(1 + x\right) \cdot \frac{x + -1}{1}}} \]
    11. metadata-eval16.5%

      \[\leadsto \frac{-2}{x} + \left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot \frac{\color{blue}{1}}{\left(1 + x\right) \cdot \frac{x + -1}{1}} \]
    12. +-commutative16.5%

      \[\leadsto \frac{-2}{x} + \left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot \frac{1}{\color{blue}{\left(x + 1\right)} \cdot \frac{x + -1}{1}} \]
    13. /-rgt-identity16.5%

      \[\leadsto \frac{-2}{x} + \left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot \frac{1}{\left(x + 1\right) \cdot \color{blue}{\left(x + -1\right)}} \]
  6. Applied egg-rr16.5%

    \[\leadsto \frac{-2}{x} + \color{blue}{\left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot \frac{1}{\left(x + 1\right) \cdot \left(x + -1\right)}} \]
  7. Step-by-step derivation
    1. associate-*r/21.0%

      \[\leadsto \frac{-2}{x} + \color{blue}{\frac{\left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot 1}{\left(x + 1\right) \cdot \left(x + -1\right)}} \]
    2. *-rgt-identity21.0%

      \[\leadsto \frac{-2}{x} + \frac{\color{blue}{\left(x + 1\right) + \left(x + -1\right)}}{\left(x + 1\right) \cdot \left(x + -1\right)} \]
    3. associate-+l+21.0%

      \[\leadsto \frac{-2}{x} + \frac{\color{blue}{x + \left(1 + \left(x + -1\right)\right)}}{\left(x + 1\right) \cdot \left(x + -1\right)} \]
    4. +-commutative21.0%

      \[\leadsto \frac{-2}{x} + \frac{x + \left(1 + \color{blue}{\left(-1 + x\right)}\right)}{\left(x + 1\right) \cdot \left(x + -1\right)} \]
    5. associate-+r+21.0%

      \[\leadsto \frac{-2}{x} + \frac{x + \color{blue}{\left(\left(1 + -1\right) + x\right)}}{\left(x + 1\right) \cdot \left(x + -1\right)} \]
    6. metadata-eval21.0%

      \[\leadsto \frac{-2}{x} + \frac{x + \left(\color{blue}{0} + x\right)}{\left(x + 1\right) \cdot \left(x + -1\right)} \]
    7. *-commutative21.0%

      \[\leadsto \frac{-2}{x} + \frac{x + \left(0 + x\right)}{\color{blue}{\left(x + -1\right) \cdot \left(x + 1\right)}} \]
  8. Simplified21.0%

    \[\leadsto \frac{-2}{x} + \color{blue}{\frac{x + \left(0 + x\right)}{\left(x + -1\right) \cdot \left(x + 1\right)}} \]
  9. Applied egg-rr0.0%

    \[\leadsto \color{blue}{\frac{\frac{-8}{{x}^{3}} + \frac{\frac{0}{0}}{{\left(\mathsf{fma}\left(x, x, -1\right)\right)}^{3}}}{\frac{4}{{x}^{2}} + \frac{0}{0 \cdot \mathsf{fma}\left(x, x, -1\right)} \cdot \left(\frac{0}{0 \cdot \mathsf{fma}\left(x, x, -1\right)} - \frac{-2}{x}\right)}} \]
  10. Simplified3.4%

    \[\leadsto \color{blue}{-9} \]
  11. Final simplification3.4%

    \[\leadsto -9 \]
  12. Add Preprocessing

Alternative 7: 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 69.2%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. associate-+l-69.2%

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

      \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\left(\frac{2}{x} - \frac{1}{x - 1}\right)\right)} \]
    3. +-commutative69.2%

      \[\leadsto \frac{1}{\color{blue}{1 + x}} + \left(-\left(\frac{2}{x} - \frac{1}{x - 1}\right)\right) \]
    4. neg-sub069.2%

      \[\leadsto \frac{1}{1 + x} + \color{blue}{\left(0 - \left(\frac{2}{x} - \frac{1}{x - 1}\right)\right)} \]
    5. associate-+l-69.2%

      \[\leadsto \frac{1}{1 + x} + \color{blue}{\left(\left(0 - \frac{2}{x}\right) + \frac{1}{x - 1}\right)} \]
    6. neg-sub069.2%

      \[\leadsto \frac{1}{1 + x} + \left(\color{blue}{\left(-\frac{2}{x}\right)} + \frac{1}{x - 1}\right) \]
    7. distribute-neg-frac69.2%

      \[\leadsto \frac{1}{1 + x} + \left(\color{blue}{\frac{-2}{x}} + \frac{1}{x - 1}\right) \]
    8. metadata-eval69.2%

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

      \[\leadsto \frac{1}{1 + x} + \left(\frac{-2}{x} + \frac{1}{\color{blue}{x + \left(-1\right)}}\right) \]
    10. metadata-eval69.2%

      \[\leadsto \frac{1}{1 + x} + \left(\frac{-2}{x} + \frac{1}{x + \color{blue}{-1}}\right) \]
  3. Simplified69.2%

    \[\leadsto \color{blue}{\frac{1}{1 + x} + \left(\frac{-2}{x} + \frac{1}{x + -1}\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. clear-num69.2%

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

      \[\leadsto \frac{1}{1 + x} + \left(\frac{1}{\frac{x}{-2}} + \color{blue}{\frac{-1}{-\left(x + -1\right)}}\right) \]
    3. metadata-eval69.2%

      \[\leadsto \frac{1}{1 + x} + \left(\frac{1}{\frac{x}{-2}} + \frac{\color{blue}{-1}}{-\left(x + -1\right)}\right) \]
    4. frac-add21.1%

      \[\leadsto \frac{1}{1 + x} + \color{blue}{\frac{1 \cdot \left(-\left(x + -1\right)\right) + \frac{x}{-2} \cdot -1}{\frac{x}{-2} \cdot \left(-\left(x + -1\right)\right)}} \]
    5. *-un-lft-identity21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\color{blue}{\left(-\left(x + -1\right)\right)} + \frac{x}{-2} \cdot -1}{\frac{x}{-2} \cdot \left(-\left(x + -1\right)\right)} \]
    6. +-commutative21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\left(-\color{blue}{\left(-1 + x\right)}\right) + \frac{x}{-2} \cdot -1}{\frac{x}{-2} \cdot \left(-\left(x + -1\right)\right)} \]
    7. distribute-neg-in21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\color{blue}{\left(\left(--1\right) + \left(-x\right)\right)} + \frac{x}{-2} \cdot -1}{\frac{x}{-2} \cdot \left(-\left(x + -1\right)\right)} \]
    8. metadata-eval21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\left(\color{blue}{1} + \left(-x\right)\right) + \frac{x}{-2} \cdot -1}{\frac{x}{-2} \cdot \left(-\left(x + -1\right)\right)} \]
    9. sub-neg21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\color{blue}{\left(1 - x\right)} + \frac{x}{-2} \cdot -1}{\frac{x}{-2} \cdot \left(-\left(x + -1\right)\right)} \]
    10. div-inv21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\left(1 - x\right) + \color{blue}{\left(x \cdot \frac{1}{-2}\right)} \cdot -1}{\frac{x}{-2} \cdot \left(-\left(x + -1\right)\right)} \]
    11. metadata-eval21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\left(1 - x\right) + \left(x \cdot \color{blue}{-0.5}\right) \cdot -1}{\frac{x}{-2} \cdot \left(-\left(x + -1\right)\right)} \]
    12. div-inv21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\left(1 - x\right) + \left(x \cdot -0.5\right) \cdot -1}{\color{blue}{\left(x \cdot \frac{1}{-2}\right)} \cdot \left(-\left(x + -1\right)\right)} \]
    13. metadata-eval21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\left(1 - x\right) + \left(x \cdot -0.5\right) \cdot -1}{\left(x \cdot \color{blue}{-0.5}\right) \cdot \left(-\left(x + -1\right)\right)} \]
    14. +-commutative21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\left(1 - x\right) + \left(x \cdot -0.5\right) \cdot -1}{\left(x \cdot -0.5\right) \cdot \left(-\color{blue}{\left(-1 + x\right)}\right)} \]
    15. distribute-neg-in21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\left(1 - x\right) + \left(x \cdot -0.5\right) \cdot -1}{\left(x \cdot -0.5\right) \cdot \color{blue}{\left(\left(--1\right) + \left(-x\right)\right)}} \]
    16. metadata-eval21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\left(1 - x\right) + \left(x \cdot -0.5\right) \cdot -1}{\left(x \cdot -0.5\right) \cdot \left(\color{blue}{1} + \left(-x\right)\right)} \]
    17. sub-neg21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\left(1 - x\right) + \left(x \cdot -0.5\right) \cdot -1}{\left(x \cdot -0.5\right) \cdot \color{blue}{\left(1 - x\right)}} \]
  6. Applied egg-rr21.1%

    \[\leadsto \frac{1}{1 + x} + \color{blue}{\frac{\left(1 - x\right) + \left(x \cdot -0.5\right) \cdot -1}{\left(x \cdot -0.5\right) \cdot \left(1 - x\right)}} \]
  7. Step-by-step derivation
    1. associate-+l-21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\color{blue}{1 - \left(x - \left(x \cdot -0.5\right) \cdot -1\right)}}{\left(x \cdot -0.5\right) \cdot \left(1 - x\right)} \]
    2. *-commutative21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \left(x - \color{blue}{-1 \cdot \left(x \cdot -0.5\right)}\right)}{\left(x \cdot -0.5\right) \cdot \left(1 - x\right)} \]
    3. associate-*r*21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \left(x - \color{blue}{\left(-1 \cdot x\right) \cdot -0.5}\right)}{\left(x \cdot -0.5\right) \cdot \left(1 - x\right)} \]
    4. neg-mul-121.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \left(x - \color{blue}{\left(-x\right)} \cdot -0.5\right)}{\left(x \cdot -0.5\right) \cdot \left(1 - x\right)} \]
    5. cancel-sign-sub21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \color{blue}{\left(x + x \cdot -0.5\right)}}{\left(x \cdot -0.5\right) \cdot \left(1 - x\right)} \]
    6. +-commutative21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \color{blue}{\left(x \cdot -0.5 + x\right)}}{\left(x \cdot -0.5\right) \cdot \left(1 - x\right)} \]
    7. *-commutative21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \left(\color{blue}{-0.5 \cdot x} + x\right)}{\left(x \cdot -0.5\right) \cdot \left(1 - x\right)} \]
    8. distribute-lft1-in21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \color{blue}{\left(-0.5 + 1\right) \cdot x}}{\left(x \cdot -0.5\right) \cdot \left(1 - x\right)} \]
    9. metadata-eval21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \color{blue}{0.5} \cdot x}{\left(x \cdot -0.5\right) \cdot \left(1 - x\right)} \]
    10. metadata-eval21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \color{blue}{\frac{1}{2}} \cdot x}{\left(x \cdot -0.5\right) \cdot \left(1 - x\right)} \]
    11. *-commutative21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \color{blue}{x \cdot \frac{1}{2}}}{\left(x \cdot -0.5\right) \cdot \left(1 - x\right)} \]
    12. metadata-eval21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - x \cdot \color{blue}{0.5}}{\left(x \cdot -0.5\right) \cdot \left(1 - x\right)} \]
    13. associate-*l*21.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - x \cdot 0.5}{\color{blue}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)}} \]
  8. Simplified21.1%

    \[\leadsto \frac{1}{1 + x} + \color{blue}{\frac{1 - x \cdot 0.5}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)}} \]
  9. Taylor expanded in x around 0 3.3%

    \[\leadsto \frac{1}{1 + x} + \frac{1 - x \cdot 0.5}{\color{blue}{-0.5 \cdot x}} \]
  10. Taylor expanded in x around inf 3.3%

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

    \[\leadsto 1 \]
  12. Add Preprocessing

Developer target: 99.2% accurate, 1.7× speedup?

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

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

Reproduce

?
herbie shell --seed 2024020 
(FPCore (x)
  :name "3frac (problem 3.3.3)"
  :precision binary64
  :pre (> (fabs x) 1.0)

  :herbie-target
  (/ 2.0 (* x (- (* x x) 1.0)))

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