3frac (problem 3.3.3)

Percentage Accurate: 69.3% → 99.5%
Time: 11.7s
Alternatives: 10
Speedup: 1.0×

Specification

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

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

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 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: 69.3% accurate, 1.0× speedup?

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

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

Alternative 1: 99.5% accurate, 0.1× speedup?

\[\begin{array}{l} \\ 2 \cdot \left({x}^{-3} + {x}^{-5}\right) \end{array} \]
(FPCore (x) :precision binary64 (* 2.0 (+ (pow x -3.0) (pow x -5.0))))
double code(double x) {
	return 2.0 * (pow(x, -3.0) + pow(x, -5.0));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 2.0d0 * ((x ** (-3.0d0)) + (x ** (-5.0d0)))
end function
public static double code(double x) {
	return 2.0 * (Math.pow(x, -3.0) + Math.pow(x, -5.0));
}
def code(x):
	return 2.0 * (math.pow(x, -3.0) + math.pow(x, -5.0))
function code(x)
	return Float64(2.0 * Float64((x ^ -3.0) + (x ^ -5.0)))
end
function tmp = code(x)
	tmp = 2.0 * ((x ^ -3.0) + (x ^ -5.0));
end
code[x_] := N[(2.0 * N[(N[Power[x, -3.0], $MachinePrecision] + N[Power[x, -5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
2 \cdot \left({x}^{-3} + {x}^{-5}\right)
\end{array}
Derivation
  1. Initial program 62.9%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. sub-neg62.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x + 1} + \left(-\frac{2}{x}\right)\right)} + \frac{1}{x - 1} \]
    2. distribute-neg-frac62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{-2}{x}}\right) + \frac{1}{x - 1} \]
    3. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{-2}}{x}\right) + \frac{1}{x - 1} \]
    4. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{\frac{2}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    5. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\frac{2}{\color{blue}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    6. associate-/r*62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{2}{\left(-1\right) \cdot x}}\right) + \frac{1}{x - 1} \]
    7. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-1} \cdot x}\right) + \frac{1}{x - 1} \]
    8. neg-mul-162.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-x}}\right) + \frac{1}{x - 1} \]
    9. +-commutative62.9%

      \[\leadsto \color{blue}{\left(\frac{2}{-x} + \frac{1}{x + 1}\right)} + \frac{1}{x - 1} \]
    10. associate-+l+62.9%

      \[\leadsto \color{blue}{\frac{2}{-x} + \left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    11. +-commutative62.9%

      \[\leadsto \frac{2}{-x} + \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right)} \]
    12. neg-mul-162.9%

      \[\leadsto \frac{2}{\color{blue}{-1 \cdot x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    13. metadata-eval62.9%

      \[\leadsto \frac{2}{\color{blue}{\left(-1\right)} \cdot x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    14. associate-/r*62.9%

      \[\leadsto \color{blue}{\frac{\frac{2}{-1}}{x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    15. metadata-eval62.9%

      \[\leadsto \frac{\frac{2}{\color{blue}{-1}}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    16. metadata-eval62.9%

      \[\leadsto \frac{\color{blue}{-2}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    17. +-commutative62.9%

      \[\leadsto \frac{-2}{x} + \color{blue}{\left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    18. +-commutative62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{\color{blue}{1 + x}} + \frac{1}{x - 1}\right) \]
    19. sub-neg62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{\color{blue}{x + \left(-1\right)}}\right) \]
    20. metadata-eval62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + \color{blue}{-1}}\right) \]
  3. Simplified62.9%

    \[\leadsto \color{blue}{\frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + -1}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 98.8%

    \[\leadsto \color{blue}{2 \cdot \frac{1}{{x}^{3}} + 2 \cdot \frac{1}{{x}^{5}}} \]
  6. Step-by-step derivation
    1. associate-*r/98.8%

      \[\leadsto \color{blue}{\frac{2 \cdot 1}{{x}^{3}}} + 2 \cdot \frac{1}{{x}^{5}} \]
    2. metadata-eval98.8%

      \[\leadsto \frac{\color{blue}{2}}{{x}^{3}} + 2 \cdot \frac{1}{{x}^{5}} \]
    3. associate-*r/98.8%

      \[\leadsto \frac{2}{{x}^{3}} + \color{blue}{\frac{2 \cdot 1}{{x}^{5}}} \]
    4. metadata-eval98.8%

      \[\leadsto \frac{2}{{x}^{3}} + \frac{\color{blue}{2}}{{x}^{5}} \]
  7. Simplified98.8%

    \[\leadsto \color{blue}{\frac{2}{{x}^{3}} + \frac{2}{{x}^{5}}} \]
  8. Step-by-step derivation
    1. expm1-log1p-u98.8%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{2}{{x}^{3}} + \frac{2}{{x}^{5}}\right)\right)} \]
    2. expm1-udef62.4%

      \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\frac{2}{{x}^{3}} + \frac{2}{{x}^{5}}\right)} - 1} \]
    3. +-commutative62.4%

      \[\leadsto e^{\mathsf{log1p}\left(\color{blue}{\frac{2}{{x}^{5}} + \frac{2}{{x}^{3}}}\right)} - 1 \]
    4. div-inv62.4%

      \[\leadsto e^{\mathsf{log1p}\left(\color{blue}{2 \cdot \frac{1}{{x}^{5}}} + \frac{2}{{x}^{3}}\right)} - 1 \]
    5. fma-def62.4%

      \[\leadsto e^{\mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(2, \frac{1}{{x}^{5}}, \frac{2}{{x}^{3}}\right)}\right)} - 1 \]
    6. pow-flip62.4%

      \[\leadsto e^{\mathsf{log1p}\left(\mathsf{fma}\left(2, \color{blue}{{x}^{\left(-5\right)}}, \frac{2}{{x}^{3}}\right)\right)} - 1 \]
    7. metadata-eval62.4%

      \[\leadsto e^{\mathsf{log1p}\left(\mathsf{fma}\left(2, {x}^{\color{blue}{-5}}, \frac{2}{{x}^{3}}\right)\right)} - 1 \]
    8. div-inv62.4%

      \[\leadsto e^{\mathsf{log1p}\left(\mathsf{fma}\left(2, {x}^{-5}, \color{blue}{2 \cdot \frac{1}{{x}^{3}}}\right)\right)} - 1 \]
    9. pow-flip62.4%

      \[\leadsto e^{\mathsf{log1p}\left(\mathsf{fma}\left(2, {x}^{-5}, 2 \cdot \color{blue}{{x}^{\left(-3\right)}}\right)\right)} - 1 \]
    10. metadata-eval62.4%

      \[\leadsto e^{\mathsf{log1p}\left(\mathsf{fma}\left(2, {x}^{-5}, 2 \cdot {x}^{\color{blue}{-3}}\right)\right)} - 1 \]
  9. Applied egg-rr62.4%

    \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\mathsf{fma}\left(2, {x}^{-5}, 2 \cdot {x}^{-3}\right)\right)} - 1} \]
  10. Step-by-step derivation
    1. expm1-def100.0%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\mathsf{fma}\left(2, {x}^{-5}, 2 \cdot {x}^{-3}\right)\right)\right)} \]
    2. expm1-log1p100.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(2, {x}^{-5}, 2 \cdot {x}^{-3}\right)} \]
    3. fma-udef100.0%

      \[\leadsto \color{blue}{2 \cdot {x}^{-5} + 2 \cdot {x}^{-3}} \]
    4. +-commutative100.0%

      \[\leadsto \color{blue}{2 \cdot {x}^{-3} + 2 \cdot {x}^{-5}} \]
    5. distribute-lft-out100.0%

      \[\leadsto \color{blue}{2 \cdot \left({x}^{-3} + {x}^{-5}\right)} \]
  11. Simplified100.0%

    \[\leadsto \color{blue}{2 \cdot \left({x}^{-3} + {x}^{-5}\right)} \]
  12. Final simplification100.0%

    \[\leadsto 2 \cdot \left({x}^{-3} + {x}^{-5}\right) \]
  13. Add Preprocessing

Alternative 2: 99.0% accurate, 0.1× speedup?

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

\\
2 \cdot {x}^{-3}
\end{array}
Derivation
  1. Initial program 62.9%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. sub-neg62.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x + 1} + \left(-\frac{2}{x}\right)\right)} + \frac{1}{x - 1} \]
    2. distribute-neg-frac62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{-2}{x}}\right) + \frac{1}{x - 1} \]
    3. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{-2}}{x}\right) + \frac{1}{x - 1} \]
    4. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{\frac{2}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    5. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\frac{2}{\color{blue}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    6. associate-/r*62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{2}{\left(-1\right) \cdot x}}\right) + \frac{1}{x - 1} \]
    7. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-1} \cdot x}\right) + \frac{1}{x - 1} \]
    8. neg-mul-162.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-x}}\right) + \frac{1}{x - 1} \]
    9. +-commutative62.9%

      \[\leadsto \color{blue}{\left(\frac{2}{-x} + \frac{1}{x + 1}\right)} + \frac{1}{x - 1} \]
    10. associate-+l+62.9%

      \[\leadsto \color{blue}{\frac{2}{-x} + \left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    11. +-commutative62.9%

      \[\leadsto \frac{2}{-x} + \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right)} \]
    12. neg-mul-162.9%

      \[\leadsto \frac{2}{\color{blue}{-1 \cdot x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    13. metadata-eval62.9%

      \[\leadsto \frac{2}{\color{blue}{\left(-1\right)} \cdot x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    14. associate-/r*62.9%

      \[\leadsto \color{blue}{\frac{\frac{2}{-1}}{x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    15. metadata-eval62.9%

      \[\leadsto \frac{\frac{2}{\color{blue}{-1}}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    16. metadata-eval62.9%

      \[\leadsto \frac{\color{blue}{-2}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    17. +-commutative62.9%

      \[\leadsto \frac{-2}{x} + \color{blue}{\left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    18. +-commutative62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{\color{blue}{1 + x}} + \frac{1}{x - 1}\right) \]
    19. sub-neg62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{\color{blue}{x + \left(-1\right)}}\right) \]
    20. metadata-eval62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + \color{blue}{-1}}\right) \]
  3. Simplified62.9%

    \[\leadsto \color{blue}{\frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + -1}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 98.5%

    \[\leadsto \color{blue}{\frac{2}{{x}^{3}}} \]
  6. Step-by-step derivation
    1. expm1-log1p-u98.5%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{2}{{x}^{3}}\right)\right)} \]
    2. expm1-udef62.4%

      \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\frac{2}{{x}^{3}}\right)} - 1} \]
    3. div-inv62.4%

      \[\leadsto e^{\mathsf{log1p}\left(\color{blue}{2 \cdot \frac{1}{{x}^{3}}}\right)} - 1 \]
    4. pow-flip62.4%

      \[\leadsto e^{\mathsf{log1p}\left(2 \cdot \color{blue}{{x}^{\left(-3\right)}}\right)} - 1 \]
    5. metadata-eval62.4%

      \[\leadsto e^{\mathsf{log1p}\left(2 \cdot {x}^{\color{blue}{-3}}\right)} - 1 \]
  7. Applied egg-rr62.4%

    \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(2 \cdot {x}^{-3}\right)} - 1} \]
  8. Step-by-step derivation
    1. expm1-def99.6%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(2 \cdot {x}^{-3}\right)\right)} \]
    2. expm1-log1p99.6%

      \[\leadsto \color{blue}{2 \cdot {x}^{-3}} \]
  9. Simplified99.6%

    \[\leadsto \color{blue}{2 \cdot {x}^{-3}} \]
  10. Final simplification99.6%

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

Alternative 3: 69.3% accurate, 0.9× speedup?

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

\\
\frac{\frac{1}{x} - 0.5}{-0.5 \cdot \left(1 - x\right)} + \frac{1}{x + 1}
\end{array}
Derivation
  1. Initial program 62.9%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. associate-+l-62.9%

      \[\leadsto \color{blue}{\frac{1}{x + 1} - \left(\frac{2}{x} - \frac{1}{x - 1}\right)} \]
    2. sub-neg62.9%

      \[\leadsto \color{blue}{\frac{1}{x + 1} + \left(-\left(\frac{2}{x} - \frac{1}{x - 1}\right)\right)} \]
    3. +-commutative62.9%

      \[\leadsto \frac{1}{\color{blue}{1 + x}} + \left(-\left(\frac{2}{x} - \frac{1}{x - 1}\right)\right) \]
    4. neg-sub062.9%

      \[\leadsto \frac{1}{1 + x} + \color{blue}{\left(0 - \left(\frac{2}{x} - \frac{1}{x - 1}\right)\right)} \]
    5. associate-+l-62.9%

      \[\leadsto \frac{1}{1 + x} + \color{blue}{\left(\left(0 - \frac{2}{x}\right) + \frac{1}{x - 1}\right)} \]
    6. neg-sub062.9%

      \[\leadsto \frac{1}{1 + x} + \left(\color{blue}{\left(-\frac{2}{x}\right)} + \frac{1}{x - 1}\right) \]
    7. distribute-neg-frac62.9%

      \[\leadsto \frac{1}{1 + x} + \left(\color{blue}{\frac{-2}{x}} + \frac{1}{x - 1}\right) \]
    8. metadata-eval62.9%

      \[\leadsto \frac{1}{1 + x} + \left(\frac{\color{blue}{-2}}{x} + \frac{1}{x - 1}\right) \]
    9. sub-neg62.9%

      \[\leadsto \frac{1}{1 + x} + \left(\frac{-2}{x} + \frac{1}{\color{blue}{x + \left(-1\right)}}\right) \]
    10. metadata-eval62.9%

      \[\leadsto \frac{1}{1 + x} + \left(\frac{-2}{x} + \frac{1}{x + \color{blue}{-1}}\right) \]
  3. Simplified62.9%

    \[\leadsto \color{blue}{\frac{1}{1 + x} + \left(\frac{-2}{x} + \frac{1}{x + -1}\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. clear-num62.9%

      \[\leadsto \frac{1}{1 + x} + \left(\color{blue}{\frac{1}{\frac{x}{-2}}} + \frac{1}{x + -1}\right) \]
    2. frac-2neg62.9%

      \[\leadsto \frac{1}{1 + x} + \left(\frac{1}{\frac{x}{-2}} + \color{blue}{\frac{-1}{-\left(x + -1\right)}}\right) \]
    3. metadata-eval62.9%

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

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

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

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

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

      \[\leadsto \frac{1}{1 + x} + \frac{\left(\color{blue}{1} + \left(-x\right)\right) + \frac{x}{-2} \cdot -1}{\frac{x}{-2} \cdot \left(-\left(x + -1\right)\right)} \]
    9. sub-neg16.1%

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

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

      \[\leadsto \frac{1}{1 + x} + \frac{\left(1 - x\right) + \left(x \cdot \color{blue}{-0.5}\right) \cdot -1}{\frac{x}{-2} \cdot \left(-\left(x + -1\right)\right)} \]
    12. div-inv16.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\left(1 - x\right) + \left(x \cdot -0.5\right) \cdot -1}{\color{blue}{\left(x \cdot \frac{1}{-2}\right)} \cdot \left(-\left(x + -1\right)\right)} \]
    13. metadata-eval16.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\left(1 - x\right) + \left(x \cdot -0.5\right) \cdot -1}{\left(x \cdot \color{blue}{-0.5}\right) \cdot \left(-\left(x + -1\right)\right)} \]
    14. +-commutative16.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\left(1 - x\right) + \left(x \cdot -0.5\right) \cdot -1}{\left(x \cdot -0.5\right) \cdot \left(-\color{blue}{\left(-1 + x\right)}\right)} \]
    15. distribute-neg-in16.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\left(1 - x\right) + \left(x \cdot -0.5\right) \cdot -1}{\left(x \cdot -0.5\right) \cdot \color{blue}{\left(\left(--1\right) + \left(-x\right)\right)}} \]
    16. metadata-eval16.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\left(1 - x\right) + \left(x \cdot -0.5\right) \cdot -1}{\left(x \cdot -0.5\right) \cdot \left(\color{blue}{1} + \left(-x\right)\right)} \]
    17. sub-neg16.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\left(1 - x\right) + \left(x \cdot -0.5\right) \cdot -1}{\left(x \cdot -0.5\right) \cdot \color{blue}{\left(1 - x\right)}} \]
  6. Applied egg-rr16.1%

    \[\leadsto \frac{1}{1 + x} + \color{blue}{\frac{\left(1 - x\right) + \left(x \cdot -0.5\right) \cdot -1}{\left(x \cdot -0.5\right) \cdot \left(1 - x\right)}} \]
  7. Step-by-step derivation
    1. associate-*l*16.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\left(1 - x\right) + \left(x \cdot -0.5\right) \cdot -1}{\color{blue}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)}} \]
    2. associate-+l-16.1%

      \[\leadsto \frac{1}{1 + x} + \frac{\color{blue}{1 - \left(x - \left(x \cdot -0.5\right) \cdot -1\right)}}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)} \]
    3. *-commutative16.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \left(x - \color{blue}{-1 \cdot \left(x \cdot -0.5\right)}\right)}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)} \]
    4. associate-*r*16.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \left(x - \color{blue}{\left(-1 \cdot x\right) \cdot -0.5}\right)}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)} \]
    5. neg-mul-116.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \left(x - \color{blue}{\left(-x\right)} \cdot -0.5\right)}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)} \]
    6. cancel-sign-sub16.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \color{blue}{\left(x + x \cdot -0.5\right)}}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)} \]
    7. +-commutative16.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \color{blue}{\left(x \cdot -0.5 + x\right)}}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)} \]
    8. *-commutative16.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \left(\color{blue}{-0.5 \cdot x} + x\right)}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)} \]
    9. distribute-lft1-in16.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \color{blue}{\left(-0.5 + 1\right) \cdot x}}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)} \]
    10. metadata-eval16.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \color{blue}{0.5} \cdot x}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)} \]
    11. metadata-eval16.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \color{blue}{\frac{1}{2}} \cdot x}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)} \]
    12. *-commutative16.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - \color{blue}{x \cdot \frac{1}{2}}}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)} \]
    13. metadata-eval16.1%

      \[\leadsto \frac{1}{1 + x} + \frac{1 - x \cdot \color{blue}{0.5}}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)} \]
  8. Simplified16.1%

    \[\leadsto \frac{1}{1 + x} + \color{blue}{\frac{1 - x \cdot 0.5}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)}} \]
  9. Step-by-step derivation
    1. expm1-log1p-u16.1%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{1}{1 + x} + \frac{1 - x \cdot 0.5}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)}\right)\right)} \]
    2. expm1-udef62.4%

      \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\frac{1}{1 + x} + \frac{1 - x \cdot 0.5}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)}\right)} - 1} \]
    3. +-commutative62.4%

      \[\leadsto e^{\mathsf{log1p}\left(\color{blue}{\frac{1 - x \cdot 0.5}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)} + \frac{1}{1 + x}}\right)} - 1 \]
    4. +-commutative62.4%

      \[\leadsto e^{\mathsf{log1p}\left(\frac{1 - x \cdot 0.5}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)} + \frac{1}{\color{blue}{x + 1}}\right)} - 1 \]
  10. Applied egg-rr62.4%

    \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\frac{1 - x \cdot 0.5}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)} + \frac{1}{x + 1}\right)} - 1} \]
  11. Step-by-step derivation
    1. expm1-def16.1%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{1 - x \cdot 0.5}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)} + \frac{1}{x + 1}\right)\right)} \]
    2. expm1-log1p16.1%

      \[\leadsto \color{blue}{\frac{1 - x \cdot 0.5}{x \cdot \left(-0.5 \cdot \left(1 - x\right)\right)} + \frac{1}{x + 1}} \]
    3. associate-/r*63.0%

      \[\leadsto \color{blue}{\frac{\frac{1 - x \cdot 0.5}{x}}{-0.5 \cdot \left(1 - x\right)}} + \frac{1}{x + 1} \]
    4. div-sub63.0%

      \[\leadsto \frac{\color{blue}{\frac{1}{x} - \frac{x \cdot 0.5}{x}}}{-0.5 \cdot \left(1 - x\right)} + \frac{1}{x + 1} \]
    5. *-commutative63.0%

      \[\leadsto \frac{\frac{1}{x} - \frac{\color{blue}{0.5 \cdot x}}{x}}{-0.5 \cdot \left(1 - x\right)} + \frac{1}{x + 1} \]
    6. associate-/l*63.0%

      \[\leadsto \frac{\frac{1}{x} - \color{blue}{\frac{0.5}{\frac{x}{x}}}}{-0.5 \cdot \left(1 - x\right)} + \frac{1}{x + 1} \]
    7. *-inverses63.0%

      \[\leadsto \frac{\frac{1}{x} - \frac{0.5}{\color{blue}{1}}}{-0.5 \cdot \left(1 - x\right)} + \frac{1}{x + 1} \]
    8. metadata-eval63.0%

      \[\leadsto \frac{\frac{1}{x} - \color{blue}{0.5}}{-0.5 \cdot \left(1 - x\right)} + \frac{1}{x + 1} \]
  12. Simplified63.0%

    \[\leadsto \color{blue}{\frac{\frac{1}{x} - 0.5}{-0.5 \cdot \left(1 - x\right)} + \frac{1}{x + 1}} \]
  13. Final simplification63.0%

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

Alternative 4: 69.3% accurate, 1.0× speedup?

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

\\
\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x + -1}
\end{array}
Derivation
  1. Initial program 62.9%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Add Preprocessing
  3. Final simplification62.9%

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

Alternative 5: 69.3% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \frac{-2}{x} + \frac{1}{x \cdot 0.5 - \frac{0.5}{x}} \end{array} \]
(FPCore (x) :precision binary64 (+ (/ -2.0 x) (/ 1.0 (- (* x 0.5) (/ 0.5 x)))))
double code(double x) {
	return (-2.0 / x) + (1.0 / ((x * 0.5) - (0.5 / x)));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = ((-2.0d0) / x) + (1.0d0 / ((x * 0.5d0) - (0.5d0 / x)))
end function
public static double code(double x) {
	return (-2.0 / x) + (1.0 / ((x * 0.5) - (0.5 / x)));
}
def code(x):
	return (-2.0 / x) + (1.0 / ((x * 0.5) - (0.5 / x)))
function code(x)
	return Float64(Float64(-2.0 / x) + Float64(1.0 / Float64(Float64(x * 0.5) - Float64(0.5 / x))))
end
function tmp = code(x)
	tmp = (-2.0 / x) + (1.0 / ((x * 0.5) - (0.5 / x)));
end
code[x_] := N[(N[(-2.0 / x), $MachinePrecision] + N[(1.0 / N[(N[(x * 0.5), $MachinePrecision] - N[(0.5 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-2}{x} + \frac{1}{x \cdot 0.5 - \frac{0.5}{x}}
\end{array}
Derivation
  1. Initial program 62.9%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. sub-neg62.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x + 1} + \left(-\frac{2}{x}\right)\right)} + \frac{1}{x - 1} \]
    2. distribute-neg-frac62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{-2}{x}}\right) + \frac{1}{x - 1} \]
    3. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{-2}}{x}\right) + \frac{1}{x - 1} \]
    4. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{\frac{2}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    5. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\frac{2}{\color{blue}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    6. associate-/r*62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{2}{\left(-1\right) \cdot x}}\right) + \frac{1}{x - 1} \]
    7. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-1} \cdot x}\right) + \frac{1}{x - 1} \]
    8. neg-mul-162.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-x}}\right) + \frac{1}{x - 1} \]
    9. +-commutative62.9%

      \[\leadsto \color{blue}{\left(\frac{2}{-x} + \frac{1}{x + 1}\right)} + \frac{1}{x - 1} \]
    10. associate-+l+62.9%

      \[\leadsto \color{blue}{\frac{2}{-x} + \left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    11. +-commutative62.9%

      \[\leadsto \frac{2}{-x} + \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right)} \]
    12. neg-mul-162.9%

      \[\leadsto \frac{2}{\color{blue}{-1 \cdot x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    13. metadata-eval62.9%

      \[\leadsto \frac{2}{\color{blue}{\left(-1\right)} \cdot x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    14. associate-/r*62.9%

      \[\leadsto \color{blue}{\frac{\frac{2}{-1}}{x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    15. metadata-eval62.9%

      \[\leadsto \frac{\frac{2}{\color{blue}{-1}}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    16. metadata-eval62.9%

      \[\leadsto \frac{\color{blue}{-2}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    17. +-commutative62.9%

      \[\leadsto \frac{-2}{x} + \color{blue}{\left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    18. +-commutative62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{\color{blue}{1 + x}} + \frac{1}{x - 1}\right) \]
    19. sub-neg62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{\color{blue}{x + \left(-1\right)}}\right) \]
    20. metadata-eval62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + \color{blue}{-1}}\right) \]
  3. Simplified62.9%

    \[\leadsto \color{blue}{\frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + -1}\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. frac-add15.6%

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

      \[\leadsto \frac{-2}{x} + \color{blue}{\frac{1}{\frac{\left(1 + x\right) \cdot \left(x + -1\right)}{1 \cdot \left(x + -1\right) + \left(1 + x\right) \cdot 1}}} \]
    3. +-commutative19.1%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\color{blue}{\left(x + 1\right)} \cdot \left(x + -1\right)}{1 \cdot \left(x + -1\right) + \left(1 + x\right) \cdot 1}} \]
    4. *-un-lft-identity19.1%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{\color{blue}{\left(x + -1\right)} + \left(1 + x\right) \cdot 1}} \]
    5. *-rgt-identity19.1%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{\left(x + -1\right) + \color{blue}{\left(1 + x\right)}}} \]
    6. +-commutative19.1%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{\color{blue}{\left(1 + x\right) + \left(x + -1\right)}}} \]
    7. +-commutative19.1%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{\color{blue}{\left(x + 1\right)} + \left(x + -1\right)}} \]
  6. Applied egg-rr19.1%

    \[\leadsto \frac{-2}{x} + \color{blue}{\frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{\left(x + 1\right) + \left(x + -1\right)}}} \]
  7. Taylor expanded in x around 0 62.9%

    \[\leadsto \frac{-2}{x} + \frac{1}{\color{blue}{0.5 \cdot x - 0.5 \cdot \frac{1}{x}}} \]
  8. Step-by-step derivation
    1. *-commutative62.9%

      \[\leadsto \frac{-2}{x} + \frac{1}{\color{blue}{x \cdot 0.5} - 0.5 \cdot \frac{1}{x}} \]
    2. associate-*r/62.9%

      \[\leadsto \frac{-2}{x} + \frac{1}{x \cdot 0.5 - \color{blue}{\frac{0.5 \cdot 1}{x}}} \]
    3. metadata-eval62.9%

      \[\leadsto \frac{-2}{x} + \frac{1}{x \cdot 0.5 - \frac{\color{blue}{0.5}}{x}} \]
  9. Simplified62.9%

    \[\leadsto \frac{-2}{x} + \frac{1}{\color{blue}{x \cdot 0.5 - \frac{0.5}{x}}} \]
  10. Final simplification62.9%

    \[\leadsto \frac{-2}{x} + \frac{1}{x \cdot 0.5 - \frac{0.5}{x}} \]
  11. Add Preprocessing

Alternative 6: 67.9% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \frac{-2}{x} + \frac{1}{0.5 \cdot \left(x + -1\right)} \end{array} \]
(FPCore (x) :precision binary64 (+ (/ -2.0 x) (/ 1.0 (* 0.5 (+ x -1.0)))))
double code(double x) {
	return (-2.0 / x) + (1.0 / (0.5 * (x + -1.0)));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = ((-2.0d0) / x) + (1.0d0 / (0.5d0 * (x + (-1.0d0))))
end function
public static double code(double x) {
	return (-2.0 / x) + (1.0 / (0.5 * (x + -1.0)));
}
def code(x):
	return (-2.0 / x) + (1.0 / (0.5 * (x + -1.0)))
function code(x)
	return Float64(Float64(-2.0 / x) + Float64(1.0 / Float64(0.5 * Float64(x + -1.0))))
end
function tmp = code(x)
	tmp = (-2.0 / x) + (1.0 / (0.5 * (x + -1.0)));
end
code[x_] := N[(N[(-2.0 / x), $MachinePrecision] + N[(1.0 / N[(0.5 * N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-2}{x} + \frac{1}{0.5 \cdot \left(x + -1\right)}
\end{array}
Derivation
  1. Initial program 62.9%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. sub-neg62.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x + 1} + \left(-\frac{2}{x}\right)\right)} + \frac{1}{x - 1} \]
    2. distribute-neg-frac62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{-2}{x}}\right) + \frac{1}{x - 1} \]
    3. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{-2}}{x}\right) + \frac{1}{x - 1} \]
    4. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{\frac{2}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    5. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\frac{2}{\color{blue}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    6. associate-/r*62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{2}{\left(-1\right) \cdot x}}\right) + \frac{1}{x - 1} \]
    7. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-1} \cdot x}\right) + \frac{1}{x - 1} \]
    8. neg-mul-162.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-x}}\right) + \frac{1}{x - 1} \]
    9. +-commutative62.9%

      \[\leadsto \color{blue}{\left(\frac{2}{-x} + \frac{1}{x + 1}\right)} + \frac{1}{x - 1} \]
    10. associate-+l+62.9%

      \[\leadsto \color{blue}{\frac{2}{-x} + \left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    11. +-commutative62.9%

      \[\leadsto \frac{2}{-x} + \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right)} \]
    12. neg-mul-162.9%

      \[\leadsto \frac{2}{\color{blue}{-1 \cdot x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    13. metadata-eval62.9%

      \[\leadsto \frac{2}{\color{blue}{\left(-1\right)} \cdot x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    14. associate-/r*62.9%

      \[\leadsto \color{blue}{\frac{\frac{2}{-1}}{x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    15. metadata-eval62.9%

      \[\leadsto \frac{\frac{2}{\color{blue}{-1}}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    16. metadata-eval62.9%

      \[\leadsto \frac{\color{blue}{-2}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    17. +-commutative62.9%

      \[\leadsto \frac{-2}{x} + \color{blue}{\left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    18. +-commutative62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{\color{blue}{1 + x}} + \frac{1}{x - 1}\right) \]
    19. sub-neg62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{\color{blue}{x + \left(-1\right)}}\right) \]
    20. metadata-eval62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + \color{blue}{-1}}\right) \]
  3. Simplified62.9%

    \[\leadsto \color{blue}{\frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + -1}\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. frac-add15.6%

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

      \[\leadsto \frac{-2}{x} + \color{blue}{\frac{1}{\frac{\left(1 + x\right) \cdot \left(x + -1\right)}{1 \cdot \left(x + -1\right) + \left(1 + x\right) \cdot 1}}} \]
    3. +-commutative19.1%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\color{blue}{\left(x + 1\right)} \cdot \left(x + -1\right)}{1 \cdot \left(x + -1\right) + \left(1 + x\right) \cdot 1}} \]
    4. *-un-lft-identity19.1%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{\color{blue}{\left(x + -1\right)} + \left(1 + x\right) \cdot 1}} \]
    5. *-rgt-identity19.1%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{\left(x + -1\right) + \color{blue}{\left(1 + x\right)}}} \]
    6. +-commutative19.1%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{\color{blue}{\left(1 + x\right) + \left(x + -1\right)}}} \]
    7. +-commutative19.1%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{\color{blue}{\left(x + 1\right)} + \left(x + -1\right)}} \]
  6. Applied egg-rr19.1%

    \[\leadsto \frac{-2}{x} + \color{blue}{\frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{\left(x + 1\right) + \left(x + -1\right)}}} \]
  7. Step-by-step derivation
    1. expm1-log1p-u3.4%

      \[\leadsto \frac{-2}{x} + \frac{1}{\color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{\left(x + 1\right) + \left(x + -1\right)}\right)\right)}} \]
    2. expm1-udef3.4%

      \[\leadsto \frac{-2}{x} + \frac{1}{\color{blue}{e^{\mathsf{log1p}\left(\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{\left(x + 1\right) + \left(x + -1\right)}\right)} - 1}} \]
  8. Applied egg-rr4.5%

    \[\leadsto \frac{-2}{x} + \frac{1}{\color{blue}{e^{\mathsf{log1p}\left(\frac{x + 1}{\frac{x + x}{x + -1}}\right)} - 1}} \]
  9. Step-by-step derivation
    1. expm1-def4.5%

      \[\leadsto \frac{-2}{x} + \frac{1}{\color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{x + 1}{\frac{x + x}{x + -1}}\right)\right)}} \]
    2. expm1-log1p62.8%

      \[\leadsto \frac{-2}{x} + \frac{1}{\color{blue}{\frac{x + 1}{\frac{x + x}{x + -1}}}} \]
    3. associate-/r/62.8%

      \[\leadsto \frac{-2}{x} + \frac{1}{\color{blue}{\frac{x + 1}{x + x} \cdot \left(x + -1\right)}} \]
    4. count-262.8%

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

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

    \[\leadsto \frac{-2}{x} + \frac{1}{\color{blue}{0.5} \cdot \left(x + -1\right)} \]
  12. Final simplification62.3%

    \[\leadsto \frac{-2}{x} + \frac{1}{0.5 \cdot \left(x + -1\right)} \]
  13. Add Preprocessing

Alternative 7: 67.8% 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 62.9%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. sub-neg62.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x + 1} + \left(-\frac{2}{x}\right)\right)} + \frac{1}{x - 1} \]
    2. distribute-neg-frac62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{-2}{x}}\right) + \frac{1}{x - 1} \]
    3. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{-2}}{x}\right) + \frac{1}{x - 1} \]
    4. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{\frac{2}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    5. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\frac{2}{\color{blue}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    6. associate-/r*62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{2}{\left(-1\right) \cdot x}}\right) + \frac{1}{x - 1} \]
    7. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-1} \cdot x}\right) + \frac{1}{x - 1} \]
    8. neg-mul-162.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-x}}\right) + \frac{1}{x - 1} \]
    9. +-commutative62.9%

      \[\leadsto \color{blue}{\left(\frac{2}{-x} + \frac{1}{x + 1}\right)} + \frac{1}{x - 1} \]
    10. associate-+l+62.9%

      \[\leadsto \color{blue}{\frac{2}{-x} + \left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    11. +-commutative62.9%

      \[\leadsto \frac{2}{-x} + \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right)} \]
    12. neg-mul-162.9%

      \[\leadsto \frac{2}{\color{blue}{-1 \cdot x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    13. metadata-eval62.9%

      \[\leadsto \frac{2}{\color{blue}{\left(-1\right)} \cdot x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    14. associate-/r*62.9%

      \[\leadsto \color{blue}{\frac{\frac{2}{-1}}{x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    15. metadata-eval62.9%

      \[\leadsto \frac{\frac{2}{\color{blue}{-1}}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    16. metadata-eval62.9%

      \[\leadsto \frac{\color{blue}{-2}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    17. +-commutative62.9%

      \[\leadsto \frac{-2}{x} + \color{blue}{\left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    18. +-commutative62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{\color{blue}{1 + x}} + \frac{1}{x - 1}\right) \]
    19. sub-neg62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{\color{blue}{x + \left(-1\right)}}\right) \]
    20. metadata-eval62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + \color{blue}{-1}}\right) \]
  3. Simplified62.9%

    \[\leadsto \color{blue}{\frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + -1}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 62.1%

    \[\leadsto \frac{-2}{x} + \color{blue}{\frac{2}{x}} \]
  6. Final simplification62.1%

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

Alternative 8: 2.9% accurate, 5.0× speedup?

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

\\
x + -2
\end{array}
Derivation
  1. Initial program 62.9%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. sub-neg62.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x + 1} + \left(-\frac{2}{x}\right)\right)} + \frac{1}{x - 1} \]
    2. distribute-neg-frac62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{-2}{x}}\right) + \frac{1}{x - 1} \]
    3. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{-2}}{x}\right) + \frac{1}{x - 1} \]
    4. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{\frac{2}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    5. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\frac{2}{\color{blue}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    6. associate-/r*62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{2}{\left(-1\right) \cdot x}}\right) + \frac{1}{x - 1} \]
    7. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-1} \cdot x}\right) + \frac{1}{x - 1} \]
    8. neg-mul-162.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-x}}\right) + \frac{1}{x - 1} \]
    9. +-commutative62.9%

      \[\leadsto \color{blue}{\left(\frac{2}{-x} + \frac{1}{x + 1}\right)} + \frac{1}{x - 1} \]
    10. associate-+l+62.9%

      \[\leadsto \color{blue}{\frac{2}{-x} + \left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    11. +-commutative62.9%

      \[\leadsto \frac{2}{-x} + \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right)} \]
    12. neg-mul-162.9%

      \[\leadsto \frac{2}{\color{blue}{-1 \cdot x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    13. metadata-eval62.9%

      \[\leadsto \frac{2}{\color{blue}{\left(-1\right)} \cdot x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    14. associate-/r*62.9%

      \[\leadsto \color{blue}{\frac{\frac{2}{-1}}{x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    15. metadata-eval62.9%

      \[\leadsto \frac{\frac{2}{\color{blue}{-1}}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    16. metadata-eval62.9%

      \[\leadsto \frac{\color{blue}{-2}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    17. +-commutative62.9%

      \[\leadsto \frac{-2}{x} + \color{blue}{\left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    18. +-commutative62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{\color{blue}{1 + x}} + \frac{1}{x - 1}\right) \]
    19. sub-neg62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{\color{blue}{x + \left(-1\right)}}\right) \]
    20. metadata-eval62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + \color{blue}{-1}}\right) \]
  3. Simplified62.9%

    \[\leadsto \color{blue}{\frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + -1}\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. frac-add15.6%

      \[\leadsto \frac{-2}{x} + \color{blue}{\frac{1 \cdot \left(x + -1\right) + \left(1 + x\right) \cdot 1}{\left(1 + x\right) \cdot \left(x + -1\right)}} \]
    2. div-inv15.4%

      \[\leadsto \frac{-2}{x} + \color{blue}{\left(1 \cdot \left(x + -1\right) + \left(1 + x\right) \cdot 1\right) \cdot \frac{1}{\left(1 + x\right) \cdot \left(x + -1\right)}} \]
    3. *-un-lft-identity15.4%

      \[\leadsto \frac{-2}{x} + \left(\color{blue}{\left(x + -1\right)} + \left(1 + x\right) \cdot 1\right) \cdot \frac{1}{\left(1 + x\right) \cdot \left(x + -1\right)} \]
    4. *-rgt-identity15.4%

      \[\leadsto \frac{-2}{x} + \left(\left(x + -1\right) + \color{blue}{\left(1 + x\right)}\right) \cdot \frac{1}{\left(1 + x\right) \cdot \left(x + -1\right)} \]
    5. +-commutative15.4%

      \[\leadsto \frac{-2}{x} + \color{blue}{\left(\left(1 + x\right) + \left(x + -1\right)\right)} \cdot \frac{1}{\left(1 + x\right) \cdot \left(x + -1\right)} \]
    6. +-commutative15.4%

      \[\leadsto \frac{-2}{x} + \left(\color{blue}{\left(x + 1\right)} + \left(x + -1\right)\right) \cdot \frac{1}{\left(1 + x\right) \cdot \left(x + -1\right)} \]
    7. metadata-eval15.4%

      \[\leadsto \frac{-2}{x} + \left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot \frac{\color{blue}{1 \cdot 1}}{\left(1 + x\right) \cdot \left(x + -1\right)} \]
    8. frac-times15.7%

      \[\leadsto \frac{-2}{x} + \left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot \color{blue}{\left(\frac{1}{1 + x} \cdot \frac{1}{x + -1}\right)} \]
    9. clear-num15.7%

      \[\leadsto \frac{-2}{x} + \left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot \left(\frac{1}{1 + x} \cdot \color{blue}{\frac{1}{\frac{x + -1}{1}}}\right) \]
    10. frac-times15.4%

      \[\leadsto \frac{-2}{x} + \left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot \color{blue}{\frac{1 \cdot 1}{\left(1 + x\right) \cdot \frac{x + -1}{1}}} \]
    11. metadata-eval15.4%

      \[\leadsto \frac{-2}{x} + \left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot \frac{\color{blue}{1}}{\left(1 + x\right) \cdot \frac{x + -1}{1}} \]
    12. +-commutative15.4%

      \[\leadsto \frac{-2}{x} + \left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot \frac{1}{\color{blue}{\left(x + 1\right)} \cdot \frac{x + -1}{1}} \]
    13. /-rgt-identity15.4%

      \[\leadsto \frac{-2}{x} + \left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot \frac{1}{\left(x + 1\right) \cdot \color{blue}{\left(x + -1\right)}} \]
  6. Applied egg-rr15.4%

    \[\leadsto \frac{-2}{x} + \color{blue}{\left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot \frac{1}{\left(x + 1\right) \cdot \left(x + -1\right)}} \]
  7. Step-by-step derivation
    1. associate-*r/15.6%

      \[\leadsto \frac{-2}{x} + \color{blue}{\frac{\left(\left(x + 1\right) + \left(x + -1\right)\right) \cdot 1}{\left(x + 1\right) \cdot \left(x + -1\right)}} \]
    2. *-rgt-identity15.6%

      \[\leadsto \frac{-2}{x} + \frac{\color{blue}{\left(x + 1\right) + \left(x + -1\right)}}{\left(x + 1\right) \cdot \left(x + -1\right)} \]
    3. associate-+l+15.6%

      \[\leadsto \frac{-2}{x} + \frac{\color{blue}{x + \left(1 + \left(x + -1\right)\right)}}{\left(x + 1\right) \cdot \left(x + -1\right)} \]
    4. +-commutative15.6%

      \[\leadsto \frac{-2}{x} + \frac{x + \left(1 + \color{blue}{\left(-1 + x\right)}\right)}{\left(x + 1\right) \cdot \left(x + -1\right)} \]
    5. associate-+r+15.6%

      \[\leadsto \frac{-2}{x} + \frac{x + \color{blue}{\left(\left(1 + -1\right) + x\right)}}{\left(x + 1\right) \cdot \left(x + -1\right)} \]
    6. metadata-eval15.6%

      \[\leadsto \frac{-2}{x} + \frac{x + \left(\color{blue}{0} + x\right)}{\left(x + 1\right) \cdot \left(x + -1\right)} \]
    7. *-commutative15.6%

      \[\leadsto \frac{-2}{x} + \frac{x + \left(0 + x\right)}{\color{blue}{\left(x + -1\right) \cdot \left(x + 1\right)}} \]
  8. Simplified15.6%

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

      \[\leadsto \frac{-2}{x} + \color{blue}{\frac{1}{\frac{\left(x + -1\right) \cdot \left(x + 1\right)}{x + \left(0 + x\right)}}} \]
    2. *-commutative19.1%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\color{blue}{\left(x + 1\right) \cdot \left(x + -1\right)}}{x + \left(0 + x\right)}} \]
    3. add-exp-log3.2%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{x + \color{blue}{e^{\log \left(0 + x\right)}}}} \]
    4. +-lft-identity3.2%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{x + e^{\log \color{blue}{x}}}} \]
    5. log1p-expm1-u3.2%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{x + e^{\color{blue}{\mathsf{log1p}\left(\mathsf{expm1}\left(\log x\right)\right)}}}} \]
    6. expm1-def3.2%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{x + e^{\mathsf{log1p}\left(\color{blue}{e^{\log x} - 1}\right)}}} \]
    7. add-exp-log3.2%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{x + e^{\mathsf{log1p}\left(\color{blue}{x} - 1\right)}}} \]
    8. *-un-lft-identity3.2%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{x + e^{\mathsf{log1p}\left(\color{blue}{1 \cdot x} - 1\right)}}} \]
    9. fma-neg3.2%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{x + e^{\mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(1, x, -1\right)}\right)}}} \]
    10. metadata-eval3.2%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{x + e^{\mathsf{log1p}\left(\mathsf{fma}\left(1, x, \color{blue}{-1}\right)\right)}}} \]
    11. fma-def3.2%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{x + e^{\mathsf{log1p}\left(\color{blue}{1 \cdot x + -1}\right)}}} \]
    12. *-un-lft-identity3.2%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{x + e^{\mathsf{log1p}\left(\color{blue}{x} + -1\right)}}} \]
    13. log1p-udef3.2%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{x + e^{\color{blue}{\log \left(1 + \left(x + -1\right)\right)}}}} \]
    14. add-exp-log19.1%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{x + \color{blue}{\left(1 + \left(x + -1\right)\right)}}} \]
    15. associate-+l+19.1%

      \[\leadsto \frac{-2}{x} + \frac{1}{\frac{\left(x + 1\right) \cdot \left(x + -1\right)}{\color{blue}{\left(x + 1\right) + \left(x + -1\right)}}} \]
    16. associate-/r/15.4%

      \[\leadsto \frac{-2}{x} + \color{blue}{\frac{1}{\left(x + 1\right) \cdot \left(x + -1\right)} \cdot \left(\left(x + 1\right) + \left(x + -1\right)\right)} \]
  10. Applied egg-rr15.4%

    \[\leadsto \frac{-2}{x} + \color{blue}{\frac{1}{\left(x + -1\right) \cdot \left(x + 1\right)} \cdot \left(x + x\right)} \]
  11. Step-by-step derivation
    1. *-commutative15.4%

      \[\leadsto \frac{-2}{x} + \color{blue}{\left(x + x\right) \cdot \frac{1}{\left(x + -1\right) \cdot \left(x + 1\right)}} \]
    2. div-inv15.6%

      \[\leadsto \frac{-2}{x} + \color{blue}{\frac{x + x}{\left(x + -1\right) \cdot \left(x + 1\right)}} \]
    3. associate-/r*62.9%

      \[\leadsto \frac{-2}{x} + \color{blue}{\frac{\frac{x + x}{x + -1}}{x + 1}} \]
    4. clear-num62.8%

      \[\leadsto \frac{-2}{x} + \color{blue}{\frac{1}{\frac{x + 1}{\frac{x + x}{x + -1}}}} \]
    5. *-un-lft-identity62.8%

      \[\leadsto \frac{-2}{x} + \frac{1}{\color{blue}{1 \cdot \frac{x + 1}{\frac{x + x}{x + -1}}}} \]
    6. frac-add62.9%

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

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(-2, \frac{0}{0} \cdot \mathsf{fma}\left(x, x, -1\right), x\right)}{x \cdot \left(\frac{0}{0} \cdot \mathsf{fma}\left(x, x, -1\right)\right)}} \]
  13. Simplified3.0%

    \[\leadsto \color{blue}{-2 + x} \]
  14. Final simplification3.0%

    \[\leadsto x + -2 \]
  15. Add Preprocessing

Alternative 9: 5.1% accurate, 5.0× speedup?

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

\\
\frac{-2}{x}
\end{array}
Derivation
  1. Initial program 62.9%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. sub-neg62.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x + 1} + \left(-\frac{2}{x}\right)\right)} + \frac{1}{x - 1} \]
    2. distribute-neg-frac62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{-2}{x}}\right) + \frac{1}{x - 1} \]
    3. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{-2}}{x}\right) + \frac{1}{x - 1} \]
    4. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{\frac{2}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    5. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\frac{2}{\color{blue}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    6. associate-/r*62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{2}{\left(-1\right) \cdot x}}\right) + \frac{1}{x - 1} \]
    7. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-1} \cdot x}\right) + \frac{1}{x - 1} \]
    8. neg-mul-162.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-x}}\right) + \frac{1}{x - 1} \]
    9. +-commutative62.9%

      \[\leadsto \color{blue}{\left(\frac{2}{-x} + \frac{1}{x + 1}\right)} + \frac{1}{x - 1} \]
    10. associate-+l+62.9%

      \[\leadsto \color{blue}{\frac{2}{-x} + \left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    11. +-commutative62.9%

      \[\leadsto \frac{2}{-x} + \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right)} \]
    12. neg-mul-162.9%

      \[\leadsto \frac{2}{\color{blue}{-1 \cdot x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    13. metadata-eval62.9%

      \[\leadsto \frac{2}{\color{blue}{\left(-1\right)} \cdot x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    14. associate-/r*62.9%

      \[\leadsto \color{blue}{\frac{\frac{2}{-1}}{x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    15. metadata-eval62.9%

      \[\leadsto \frac{\frac{2}{\color{blue}{-1}}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    16. metadata-eval62.9%

      \[\leadsto \frac{\color{blue}{-2}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    17. +-commutative62.9%

      \[\leadsto \frac{-2}{x} + \color{blue}{\left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    18. +-commutative62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{\color{blue}{1 + x}} + \frac{1}{x - 1}\right) \]
    19. sub-neg62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{\color{blue}{x + \left(-1\right)}}\right) \]
    20. metadata-eval62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + \color{blue}{-1}}\right) \]
  3. Simplified62.9%

    \[\leadsto \color{blue}{\frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + -1}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 4.8%

    \[\leadsto \color{blue}{\frac{-2}{x}} \]
  6. Final simplification4.8%

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

Alternative 10: 3.3% accurate, 15.0× speedup?

\[\begin{array}{l} \\ -7 \end{array} \]
(FPCore (x) :precision binary64 -7.0)
double code(double x) {
	return -7.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = -7.0d0
end function
public static double code(double x) {
	return -7.0;
}
def code(x):
	return -7.0
function code(x)
	return -7.0
end
function tmp = code(x)
	tmp = -7.0;
end
code[x_] := -7.0
\begin{array}{l}

\\
-7
\end{array}
Derivation
  1. Initial program 62.9%

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1} \]
  2. Step-by-step derivation
    1. sub-neg62.9%

      \[\leadsto \color{blue}{\left(\frac{1}{x + 1} + \left(-\frac{2}{x}\right)\right)} + \frac{1}{x - 1} \]
    2. distribute-neg-frac62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{-2}{x}}\right) + \frac{1}{x - 1} \]
    3. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{-2}}{x}\right) + \frac{1}{x - 1} \]
    4. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\color{blue}{\frac{2}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    5. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{\frac{2}{\color{blue}{-1}}}{x}\right) + \frac{1}{x - 1} \]
    6. associate-/r*62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \color{blue}{\frac{2}{\left(-1\right) \cdot x}}\right) + \frac{1}{x - 1} \]
    7. metadata-eval62.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-1} \cdot x}\right) + \frac{1}{x - 1} \]
    8. neg-mul-162.9%

      \[\leadsto \left(\frac{1}{x + 1} + \frac{2}{\color{blue}{-x}}\right) + \frac{1}{x - 1} \]
    9. +-commutative62.9%

      \[\leadsto \color{blue}{\left(\frac{2}{-x} + \frac{1}{x + 1}\right)} + \frac{1}{x - 1} \]
    10. associate-+l+62.9%

      \[\leadsto \color{blue}{\frac{2}{-x} + \left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    11. +-commutative62.9%

      \[\leadsto \frac{2}{-x} + \color{blue}{\left(\frac{1}{x - 1} + \frac{1}{x + 1}\right)} \]
    12. neg-mul-162.9%

      \[\leadsto \frac{2}{\color{blue}{-1 \cdot x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    13. metadata-eval62.9%

      \[\leadsto \frac{2}{\color{blue}{\left(-1\right)} \cdot x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    14. associate-/r*62.9%

      \[\leadsto \color{blue}{\frac{\frac{2}{-1}}{x}} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    15. metadata-eval62.9%

      \[\leadsto \frac{\frac{2}{\color{blue}{-1}}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    16. metadata-eval62.9%

      \[\leadsto \frac{\color{blue}{-2}}{x} + \left(\frac{1}{x - 1} + \frac{1}{x + 1}\right) \]
    17. +-commutative62.9%

      \[\leadsto \frac{-2}{x} + \color{blue}{\left(\frac{1}{x + 1} + \frac{1}{x - 1}\right)} \]
    18. +-commutative62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{\color{blue}{1 + x}} + \frac{1}{x - 1}\right) \]
    19. sub-neg62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{\color{blue}{x + \left(-1\right)}}\right) \]
    20. metadata-eval62.9%

      \[\leadsto \frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + \color{blue}{-1}}\right) \]
  3. Simplified62.9%

    \[\leadsto \color{blue}{\frac{-2}{x} + \left(\frac{1}{1 + x} + \frac{1}{x + -1}\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 98.5%

    \[\leadsto \color{blue}{\frac{2}{{x}^{3}}} \]
  6. Step-by-step derivation
    1. expm1-log1p-u98.5%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{2}{{x}^{3}}\right)\right)} \]
    2. expm1-udef62.4%

      \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\frac{2}{{x}^{3}}\right)} - 1} \]
    3. div-inv62.4%

      \[\leadsto e^{\mathsf{log1p}\left(\color{blue}{2 \cdot \frac{1}{{x}^{3}}}\right)} - 1 \]
    4. pow-flip62.4%

      \[\leadsto e^{\mathsf{log1p}\left(2 \cdot \color{blue}{{x}^{\left(-3\right)}}\right)} - 1 \]
    5. metadata-eval62.4%

      \[\leadsto e^{\mathsf{log1p}\left(2 \cdot {x}^{\color{blue}{-3}}\right)} - 1 \]
  7. Applied egg-rr62.4%

    \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(2 \cdot {x}^{-3}\right)} - 1} \]
  8. Step-by-step derivation
    1. expm1-def99.6%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(2 \cdot {x}^{-3}\right)\right)} \]
    2. expm1-log1p99.6%

      \[\leadsto \color{blue}{2 \cdot {x}^{-3}} \]
  9. Simplified99.6%

    \[\leadsto \color{blue}{2 \cdot {x}^{-3}} \]
  10. Taylor expanded in x around 0 98.5%

    \[\leadsto \color{blue}{\frac{2}{{x}^{3}}} \]
  11. Simplified3.4%

    \[\leadsto \color{blue}{-7} \]
  12. Final simplification3.4%

    \[\leadsto -7 \]
  13. 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 2024024 
(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))))