Asymptote C

Percentage Accurate: 54.1% → 99.8%
Time: 8.9s
Alternatives: 13
Speedup: 1.0×

Specification

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

\\
\frac{x}{x + 1} - \frac{x + 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 13 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: 54.1% accurate, 1.0× speedup?

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

\\
\frac{x}{x + 1} - \frac{x + 1}{x - 1}
\end{array}

Alternative 1: 99.8% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + 1} + \frac{x + 1}{1 - x}\\ \mathbf{if}\;t\_0 \leq 0.001:\\ \;\;\;\;\frac{3 - \frac{2 - \frac{\frac{4 + \frac{4}{{x}^{2}}}{2 + \frac{2}{x}}}{x}}{x}}{1 - x}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (+ (/ x (+ x 1.0)) (/ (+ x 1.0) (- 1.0 x)))))
   (if (<= t_0 0.001)
     (/
      (-
       3.0
       (/ (- 2.0 (/ (/ (+ 4.0 (/ 4.0 (pow x 2.0))) (+ 2.0 (/ 2.0 x))) x)) x))
      (- 1.0 x))
     t_0)))
double code(double x) {
	double t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x));
	double tmp;
	if (t_0 <= 0.001) {
		tmp = (3.0 - ((2.0 - (((4.0 + (4.0 / pow(x, 2.0))) / (2.0 + (2.0 / x))) / x)) / x)) / (1.0 - x);
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (x / (x + 1.0d0)) + ((x + 1.0d0) / (1.0d0 - x))
    if (t_0 <= 0.001d0) then
        tmp = (3.0d0 - ((2.0d0 - (((4.0d0 + (4.0d0 / (x ** 2.0d0))) / (2.0d0 + (2.0d0 / x))) / x)) / x)) / (1.0d0 - x)
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x));
	double tmp;
	if (t_0 <= 0.001) {
		tmp = (3.0 - ((2.0 - (((4.0 + (4.0 / Math.pow(x, 2.0))) / (2.0 + (2.0 / x))) / x)) / x)) / (1.0 - x);
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x):
	t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x))
	tmp = 0
	if t_0 <= 0.001:
		tmp = (3.0 - ((2.0 - (((4.0 + (4.0 / math.pow(x, 2.0))) / (2.0 + (2.0 / x))) / x)) / x)) / (1.0 - x)
	else:
		tmp = t_0
	return tmp
function code(x)
	t_0 = Float64(Float64(x / Float64(x + 1.0)) + Float64(Float64(x + 1.0) / Float64(1.0 - x)))
	tmp = 0.0
	if (t_0 <= 0.001)
		tmp = Float64(Float64(3.0 - Float64(Float64(2.0 - Float64(Float64(Float64(4.0 + Float64(4.0 / (x ^ 2.0))) / Float64(2.0 + Float64(2.0 / x))) / x)) / x)) / Float64(1.0 - x));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x));
	tmp = 0.0;
	if (t_0 <= 0.001)
		tmp = (3.0 - ((2.0 - (((4.0 + (4.0 / (x ^ 2.0))) / (2.0 + (2.0 / x))) / x)) / x)) / (1.0 - x);
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] + N[(N[(x + 1.0), $MachinePrecision] / N[(1.0 - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 0.001], N[(N[(3.0 - N[(N[(2.0 - N[(N[(N[(4.0 + N[(4.0 / N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(2.0 + N[(2.0 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision] / N[(1.0 - x), $MachinePrecision]), $MachinePrecision], t$95$0]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x}{x + 1} + \frac{x + 1}{1 - x}\\
\mathbf{if}\;t\_0 \leq 0.001:\\
\;\;\;\;\frac{3 - \frac{2 - \frac{\frac{4 + \frac{4}{{x}^{2}}}{2 + \frac{2}{x}}}{x}}{x}}{1 - x}\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64)))) < 1e-3

    1. Initial program 7.9%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. remove-double-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
      2. distribute-neg-in7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
      3. sub-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
      4. distribute-frac-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
      5. distribute-frac-neg27.9%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
      6. sub-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
      7. +-commutative7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
      8. unsub-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
      9. metadata-eval7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
      10. neg-sub07.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
      11. associate-+l-7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
      12. neg-sub07.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
      13. +-commutative7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
      14. unsub-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
    3. Simplified7.9%

      \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. frac-2neg7.9%

        \[\leadsto \color{blue}{\frac{-x}{-\left(x + 1\right)}} - \frac{-1 - x}{1 - x} \]
      2. clear-num7.9%

        \[\leadsto \frac{-x}{-\left(x + 1\right)} - \color{blue}{\frac{1}{\frac{1 - x}{-1 - x}}} \]
      3. frac-sub8.0%

        \[\leadsto \color{blue}{\frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-\left(x + 1\right)\right) \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}}} \]
      4. +-commutative8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-\color{blue}{\left(1 + x\right)}\right) \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      5. distribute-neg-in8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \color{blue}{\left(\left(-1\right) + \left(-x\right)\right)} \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      6. metadata-eval8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(\color{blue}{-1} + \left(-x\right)\right) \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      7. sub-neg8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \color{blue}{\left(-1 - x\right)} \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      8. *-commutative8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \color{blue}{1 \cdot \left(-1 - x\right)}}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      9. *-un-lft-identity8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \color{blue}{\left(-1 - x\right)}}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      10. +-commutative8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\left(-\color{blue}{\left(1 + x\right)}\right) \cdot \frac{1 - x}{-1 - x}} \]
      11. distribute-neg-in8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{\left(\left(-1\right) + \left(-x\right)\right)} \cdot \frac{1 - x}{-1 - x}} \]
      12. metadata-eval8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\left(\color{blue}{-1} + \left(-x\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      13. sub-neg8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{\left(-1 - x\right)} \cdot \frac{1 - x}{-1 - x}} \]
    6. Applied egg-rr8.0%

      \[\leadsto \color{blue}{\frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\left(-1 - x\right) \cdot \frac{1 - x}{-1 - x}}} \]
    7. Taylor expanded in x around 0 8.0%

      \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{1 + -1 \cdot x}} \]
    8. Step-by-step derivation
      1. mul-1-neg8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{1 + \color{blue}{\left(-x\right)}} \]
      2. unsub-neg8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{1 - x}} \]
    9. Simplified8.0%

      \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{1 - x}} \]
    10. Taylor expanded in x around -inf 99.5%

      \[\leadsto \frac{\color{blue}{3 + -1 \cdot \frac{2 + -1 \cdot \frac{2 - 2 \cdot \frac{1}{x}}{x}}{x}}}{1 - x} \]
    11. Step-by-step derivation
      1. mul-1-neg99.5%

        \[\leadsto \frac{3 + \color{blue}{\left(-\frac{2 + -1 \cdot \frac{2 - 2 \cdot \frac{1}{x}}{x}}{x}\right)}}{1 - x} \]
      2. unsub-neg99.5%

        \[\leadsto \frac{\color{blue}{3 - \frac{2 + -1 \cdot \frac{2 - 2 \cdot \frac{1}{x}}{x}}{x}}}{1 - x} \]
      3. mul-1-neg99.5%

        \[\leadsto \frac{3 - \frac{2 + \color{blue}{\left(-\frac{2 - 2 \cdot \frac{1}{x}}{x}\right)}}{x}}{1 - x} \]
      4. unsub-neg99.5%

        \[\leadsto \frac{3 - \frac{\color{blue}{2 - \frac{2 - 2 \cdot \frac{1}{x}}{x}}}{x}}{1 - x} \]
      5. sub-neg99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\color{blue}{2 + \left(-2 \cdot \frac{1}{x}\right)}}{x}}{x}}{1 - x} \]
      6. associate-*r/99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{2 + \left(-\color{blue}{\frac{2 \cdot 1}{x}}\right)}{x}}{x}}{1 - x} \]
      7. metadata-eval99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{2 + \left(-\frac{\color{blue}{2}}{x}\right)}{x}}{x}}{1 - x} \]
      8. distribute-neg-frac99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{2 + \color{blue}{\frac{-2}{x}}}{x}}{x}}{1 - x} \]
      9. metadata-eval99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{2 + \frac{\color{blue}{-2}}{x}}{x}}{x}}{1 - x} \]
    12. Simplified99.5%

      \[\leadsto \frac{\color{blue}{3 - \frac{2 - \frac{2 + \frac{-2}{x}}{x}}{x}}}{1 - x} \]
    13. Step-by-step derivation
      1. flip-+99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\color{blue}{\frac{2 \cdot 2 - \frac{-2}{x} \cdot \frac{-2}{x}}{2 - \frac{-2}{x}}}}{x}}{x}}{1 - x} \]
      2. div-inv99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\color{blue}{\left(2 \cdot 2 - \frac{-2}{x} \cdot \frac{-2}{x}\right) \cdot \frac{1}{2 - \frac{-2}{x}}}}{x}}{x}}{1 - x} \]
      3. cancel-sign-sub-inv99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\color{blue}{\left(2 \cdot 2 + \left(-\frac{-2}{x}\right) \cdot \frac{-2}{x}\right)} \cdot \frac{1}{2 - \frac{-2}{x}}}{x}}{x}}{1 - x} \]
      4. metadata-eval99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\left(\color{blue}{4} + \left(-\frac{-2}{x}\right) \cdot \frac{-2}{x}\right) \cdot \frac{1}{2 - \frac{-2}{x}}}{x}}{x}}{1 - x} \]
      5. distribute-frac-neg299.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\left(4 + \color{blue}{\frac{-2}{-x}} \cdot \frac{-2}{x}\right) \cdot \frac{1}{2 - \frac{-2}{x}}}{x}}{x}}{1 - x} \]
      6. metadata-eval99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\left(4 + \frac{\color{blue}{-2}}{-x} \cdot \frac{-2}{x}\right) \cdot \frac{1}{2 - \frac{-2}{x}}}{x}}{x}}{1 - x} \]
      7. frac-2neg99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\left(4 + \color{blue}{\frac{2}{x}} \cdot \frac{-2}{x}\right) \cdot \frac{1}{2 - \frac{-2}{x}}}{x}}{x}}{1 - x} \]
      8. add-sqr-sqrt43.7%

        \[\leadsto \frac{3 - \frac{2 - \frac{\left(4 + \frac{2}{x} \cdot \color{blue}{\left(\sqrt{\frac{-2}{x}} \cdot \sqrt{\frac{-2}{x}}\right)}\right) \cdot \frac{1}{2 - \frac{-2}{x}}}{x}}{x}}{1 - x} \]
      9. sqrt-unprod99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\left(4 + \frac{2}{x} \cdot \color{blue}{\sqrt{\frac{-2}{x} \cdot \frac{-2}{x}}}\right) \cdot \frac{1}{2 - \frac{-2}{x}}}{x}}{x}}{1 - x} \]
      10. frac-times99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\left(4 + \frac{2}{x} \cdot \sqrt{\color{blue}{\frac{-2 \cdot -2}{x \cdot x}}}\right) \cdot \frac{1}{2 - \frac{-2}{x}}}{x}}{x}}{1 - x} \]
      11. metadata-eval99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\left(4 + \frac{2}{x} \cdot \sqrt{\frac{\color{blue}{4}}{x \cdot x}}\right) \cdot \frac{1}{2 - \frac{-2}{x}}}{x}}{x}}{1 - x} \]
      12. metadata-eval99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\left(4 + \frac{2}{x} \cdot \sqrt{\frac{\color{blue}{2 \cdot 2}}{x \cdot x}}\right) \cdot \frac{1}{2 - \frac{-2}{x}}}{x}}{x}}{1 - x} \]
      13. frac-times99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\left(4 + \frac{2}{x} \cdot \sqrt{\color{blue}{\frac{2}{x} \cdot \frac{2}{x}}}\right) \cdot \frac{1}{2 - \frac{-2}{x}}}{x}}{x}}{1 - x} \]
      14. sqrt-unprod55.8%

        \[\leadsto \frac{3 - \frac{2 - \frac{\left(4 + \frac{2}{x} \cdot \color{blue}{\left(\sqrt{\frac{2}{x}} \cdot \sqrt{\frac{2}{x}}\right)}\right) \cdot \frac{1}{2 - \frac{-2}{x}}}{x}}{x}}{1 - x} \]
      15. add-sqr-sqrt99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\left(4 + \frac{2}{x} \cdot \color{blue}{\frac{2}{x}}\right) \cdot \frac{1}{2 - \frac{-2}{x}}}{x}}{x}}{1 - x} \]
      16. frac-times99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\left(4 + \color{blue}{\frac{2 \cdot 2}{x \cdot x}}\right) \cdot \frac{1}{2 - \frac{-2}{x}}}{x}}{x}}{1 - x} \]
      17. metadata-eval99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\left(4 + \frac{\color{blue}{4}}{x \cdot x}\right) \cdot \frac{1}{2 - \frac{-2}{x}}}{x}}{x}}{1 - x} \]
      18. pow299.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\left(4 + \frac{4}{\color{blue}{{x}^{2}}}\right) \cdot \frac{1}{2 - \frac{-2}{x}}}{x}}{x}}{1 - x} \]
      19. sub-neg99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\left(4 + \frac{4}{{x}^{2}}\right) \cdot \frac{1}{\color{blue}{2 + \left(-\frac{-2}{x}\right)}}}{x}}{x}}{1 - x} \]
      20. distribute-frac-neg299.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\left(4 + \frac{4}{{x}^{2}}\right) \cdot \frac{1}{2 + \color{blue}{\frac{-2}{-x}}}}{x}}{x}}{1 - x} \]
      21. metadata-eval99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\left(4 + \frac{4}{{x}^{2}}\right) \cdot \frac{1}{2 + \frac{\color{blue}{-2}}{-x}}}{x}}{x}}{1 - x} \]
      22. frac-2neg99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\left(4 + \frac{4}{{x}^{2}}\right) \cdot \frac{1}{2 + \color{blue}{\frac{2}{x}}}}{x}}{x}}{1 - x} \]
    14. Applied egg-rr99.5%

      \[\leadsto \frac{3 - \frac{2 - \frac{\color{blue}{\left(4 + \frac{4}{{x}^{2}}\right) \cdot \frac{1}{2 + \frac{2}{x}}}}{x}}{x}}{1 - x} \]
    15. Step-by-step derivation
      1. associate-*r/99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\color{blue}{\frac{\left(4 + \frac{4}{{x}^{2}}\right) \cdot 1}{2 + \frac{2}{x}}}}{x}}{x}}{1 - x} \]
      2. *-rgt-identity99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\frac{\color{blue}{4 + \frac{4}{{x}^{2}}}}{2 + \frac{2}{x}}}{x}}{x}}{1 - x} \]
    16. Simplified99.5%

      \[\leadsto \frac{3 - \frac{2 - \frac{\color{blue}{\frac{4 + \frac{4}{{x}^{2}}}{2 + \frac{2}{x}}}}{x}}{x}}{1 - x} \]

    if 1e-3 < (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64))))

    1. Initial program 100.0%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Add Preprocessing
  3. Recombined 2 regimes into one program.
  4. Final simplification99.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{x + 1} + \frac{x + 1}{1 - x} \leq 0.001:\\ \;\;\;\;\frac{3 - \frac{2 - \frac{\frac{4 + \frac{4}{{x}^{2}}}{2 + \frac{2}{x}}}{x}}{x}}{1 - x}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{x + 1} + \frac{x + 1}{1 - x}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 99.8% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + 1} + \frac{x + 1}{1 - x}\\ \mathbf{if}\;t\_0 \leq 0.001:\\ \;\;\;\;\frac{3}{1 - x} + \frac{2 + \frac{\frac{2}{x} + -2}{x}}{x \cdot \left(x + -1\right)}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (+ (/ x (+ x 1.0)) (/ (+ x 1.0) (- 1.0 x)))))
   (if (<= t_0 0.001)
     (+
      (/ 3.0 (- 1.0 x))
      (/ (+ 2.0 (/ (+ (/ 2.0 x) -2.0) x)) (* x (+ x -1.0))))
     t_0)))
double code(double x) {
	double t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x));
	double tmp;
	if (t_0 <= 0.001) {
		tmp = (3.0 / (1.0 - x)) + ((2.0 + (((2.0 / x) + -2.0) / x)) / (x * (x + -1.0)));
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (x / (x + 1.0d0)) + ((x + 1.0d0) / (1.0d0 - x))
    if (t_0 <= 0.001d0) then
        tmp = (3.0d0 / (1.0d0 - x)) + ((2.0d0 + (((2.0d0 / x) + (-2.0d0)) / x)) / (x * (x + (-1.0d0))))
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x));
	double tmp;
	if (t_0 <= 0.001) {
		tmp = (3.0 / (1.0 - x)) + ((2.0 + (((2.0 / x) + -2.0) / x)) / (x * (x + -1.0)));
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x):
	t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x))
	tmp = 0
	if t_0 <= 0.001:
		tmp = (3.0 / (1.0 - x)) + ((2.0 + (((2.0 / x) + -2.0) / x)) / (x * (x + -1.0)))
	else:
		tmp = t_0
	return tmp
function code(x)
	t_0 = Float64(Float64(x / Float64(x + 1.0)) + Float64(Float64(x + 1.0) / Float64(1.0 - x)))
	tmp = 0.0
	if (t_0 <= 0.001)
		tmp = Float64(Float64(3.0 / Float64(1.0 - x)) + Float64(Float64(2.0 + Float64(Float64(Float64(2.0 / x) + -2.0) / x)) / Float64(x * Float64(x + -1.0))));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x));
	tmp = 0.0;
	if (t_0 <= 0.001)
		tmp = (3.0 / (1.0 - x)) + ((2.0 + (((2.0 / x) + -2.0) / x)) / (x * (x + -1.0)));
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] + N[(N[(x + 1.0), $MachinePrecision] / N[(1.0 - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 0.001], N[(N[(3.0 / N[(1.0 - x), $MachinePrecision]), $MachinePrecision] + N[(N[(2.0 + N[(N[(N[(2.0 / x), $MachinePrecision] + -2.0), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision] / N[(x * N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$0]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x}{x + 1} + \frac{x + 1}{1 - x}\\
\mathbf{if}\;t\_0 \leq 0.001:\\
\;\;\;\;\frac{3}{1 - x} + \frac{2 + \frac{\frac{2}{x} + -2}{x}}{x \cdot \left(x + -1\right)}\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64)))) < 1e-3

    1. Initial program 7.9%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. remove-double-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
      2. distribute-neg-in7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
      3. sub-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
      4. distribute-frac-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
      5. distribute-frac-neg27.9%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
      6. sub-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
      7. +-commutative7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
      8. unsub-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
      9. metadata-eval7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
      10. neg-sub07.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
      11. associate-+l-7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
      12. neg-sub07.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
      13. +-commutative7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
      14. unsub-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
    3. Simplified7.9%

      \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. frac-2neg7.9%

        \[\leadsto \color{blue}{\frac{-x}{-\left(x + 1\right)}} - \frac{-1 - x}{1 - x} \]
      2. clear-num7.9%

        \[\leadsto \frac{-x}{-\left(x + 1\right)} - \color{blue}{\frac{1}{\frac{1 - x}{-1 - x}}} \]
      3. frac-sub8.0%

        \[\leadsto \color{blue}{\frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-\left(x + 1\right)\right) \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}}} \]
      4. +-commutative8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-\color{blue}{\left(1 + x\right)}\right) \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      5. distribute-neg-in8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \color{blue}{\left(\left(-1\right) + \left(-x\right)\right)} \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      6. metadata-eval8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(\color{blue}{-1} + \left(-x\right)\right) \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      7. sub-neg8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \color{blue}{\left(-1 - x\right)} \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      8. *-commutative8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \color{blue}{1 \cdot \left(-1 - x\right)}}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      9. *-un-lft-identity8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \color{blue}{\left(-1 - x\right)}}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      10. +-commutative8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\left(-\color{blue}{\left(1 + x\right)}\right) \cdot \frac{1 - x}{-1 - x}} \]
      11. distribute-neg-in8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{\left(\left(-1\right) + \left(-x\right)\right)} \cdot \frac{1 - x}{-1 - x}} \]
      12. metadata-eval8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\left(\color{blue}{-1} + \left(-x\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      13. sub-neg8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{\left(-1 - x\right)} \cdot \frac{1 - x}{-1 - x}} \]
    6. Applied egg-rr8.0%

      \[\leadsto \color{blue}{\frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\left(-1 - x\right) \cdot \frac{1 - x}{-1 - x}}} \]
    7. Taylor expanded in x around 0 8.0%

      \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{1 + -1 \cdot x}} \]
    8. Step-by-step derivation
      1. mul-1-neg8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{1 + \color{blue}{\left(-x\right)}} \]
      2. unsub-neg8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{1 - x}} \]
    9. Simplified8.0%

      \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{1 - x}} \]
    10. Taylor expanded in x around -inf 99.5%

      \[\leadsto \frac{\color{blue}{3 + -1 \cdot \frac{2 + -1 \cdot \frac{2 - 2 \cdot \frac{1}{x}}{x}}{x}}}{1 - x} \]
    11. Step-by-step derivation
      1. mul-1-neg99.5%

        \[\leadsto \frac{3 + \color{blue}{\left(-\frac{2 + -1 \cdot \frac{2 - 2 \cdot \frac{1}{x}}{x}}{x}\right)}}{1 - x} \]
      2. unsub-neg99.5%

        \[\leadsto \frac{\color{blue}{3 - \frac{2 + -1 \cdot \frac{2 - 2 \cdot \frac{1}{x}}{x}}{x}}}{1 - x} \]
      3. mul-1-neg99.5%

        \[\leadsto \frac{3 - \frac{2 + \color{blue}{\left(-\frac{2 - 2 \cdot \frac{1}{x}}{x}\right)}}{x}}{1 - x} \]
      4. unsub-neg99.5%

        \[\leadsto \frac{3 - \frac{\color{blue}{2 - \frac{2 - 2 \cdot \frac{1}{x}}{x}}}{x}}{1 - x} \]
      5. sub-neg99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\color{blue}{2 + \left(-2 \cdot \frac{1}{x}\right)}}{x}}{x}}{1 - x} \]
      6. associate-*r/99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{2 + \left(-\color{blue}{\frac{2 \cdot 1}{x}}\right)}{x}}{x}}{1 - x} \]
      7. metadata-eval99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{2 + \left(-\frac{\color{blue}{2}}{x}\right)}{x}}{x}}{1 - x} \]
      8. distribute-neg-frac99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{2 + \color{blue}{\frac{-2}{x}}}{x}}{x}}{1 - x} \]
      9. metadata-eval99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{2 + \frac{\color{blue}{-2}}{x}}{x}}{x}}{1 - x} \]
    12. Simplified99.5%

      \[\leadsto \frac{\color{blue}{3 - \frac{2 - \frac{2 + \frac{-2}{x}}{x}}{x}}}{1 - x} \]
    13. Step-by-step derivation
      1. div-sub99.5%

        \[\leadsto \color{blue}{\frac{3}{1 - x} - \frac{\frac{2 - \frac{2 + \frac{-2}{x}}{x}}{x}}{1 - x}} \]
      2. associate-/l/99.5%

        \[\leadsto \frac{3}{1 - x} - \color{blue}{\frac{2 - \frac{2 + \frac{-2}{x}}{x}}{\left(1 - x\right) \cdot x}} \]
      3. sub-neg99.5%

        \[\leadsto \frac{3}{1 - x} - \frac{\color{blue}{2 + \left(-\frac{2 + \frac{-2}{x}}{x}\right)}}{\left(1 - x\right) \cdot x} \]
      4. distribute-neg-frac99.5%

        \[\leadsto \frac{3}{1 - x} - \frac{2 + \color{blue}{\frac{-\left(2 + \frac{-2}{x}\right)}{x}}}{\left(1 - x\right) \cdot x} \]
      5. distribute-neg-in99.5%

        \[\leadsto \frac{3}{1 - x} - \frac{2 + \frac{\color{blue}{\left(-2\right) + \left(-\frac{-2}{x}\right)}}{x}}{\left(1 - x\right) \cdot x} \]
      6. metadata-eval99.5%

        \[\leadsto \frac{3}{1 - x} - \frac{2 + \frac{\color{blue}{-2} + \left(-\frac{-2}{x}\right)}{x}}{\left(1 - x\right) \cdot x} \]
      7. distribute-frac-neg299.5%

        \[\leadsto \frac{3}{1 - x} - \frac{2 + \frac{-2 + \color{blue}{\frac{-2}{-x}}}{x}}{\left(1 - x\right) \cdot x} \]
      8. metadata-eval99.5%

        \[\leadsto \frac{3}{1 - x} - \frac{2 + \frac{-2 + \frac{\color{blue}{-2}}{-x}}{x}}{\left(1 - x\right) \cdot x} \]
      9. frac-2neg99.5%

        \[\leadsto \frac{3}{1 - x} - \frac{2 + \frac{-2 + \color{blue}{\frac{2}{x}}}{x}}{\left(1 - x\right) \cdot x} \]
    14. Applied egg-rr99.5%

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

    if 1e-3 < (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64))))

    1. Initial program 100.0%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Add Preprocessing
  3. Recombined 2 regimes into one program.
  4. Final simplification99.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{x + 1} + \frac{x + 1}{1 - x} \leq 0.001:\\ \;\;\;\;\frac{3}{1 - x} + \frac{2 + \frac{\frac{2}{x} + -2}{x}}{x \cdot \left(x + -1\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{x + 1} + \frac{x + 1}{1 - x}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 99.8% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + 1} + \frac{x + 1}{1 - x}\\ \mathbf{if}\;t\_0 \leq 0.001:\\ \;\;\;\;\frac{3 + \frac{\frac{2 + \frac{-2}{x}}{x} - 2}{x}}{1 - x}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (+ (/ x (+ x 1.0)) (/ (+ x 1.0) (- 1.0 x)))))
   (if (<= t_0 0.001)
     (/ (+ 3.0 (/ (- (/ (+ 2.0 (/ -2.0 x)) x) 2.0) x)) (- 1.0 x))
     t_0)))
double code(double x) {
	double t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x));
	double tmp;
	if (t_0 <= 0.001) {
		tmp = (3.0 + ((((2.0 + (-2.0 / x)) / x) - 2.0) / x)) / (1.0 - x);
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (x / (x + 1.0d0)) + ((x + 1.0d0) / (1.0d0 - x))
    if (t_0 <= 0.001d0) then
        tmp = (3.0d0 + ((((2.0d0 + ((-2.0d0) / x)) / x) - 2.0d0) / x)) / (1.0d0 - x)
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x));
	double tmp;
	if (t_0 <= 0.001) {
		tmp = (3.0 + ((((2.0 + (-2.0 / x)) / x) - 2.0) / x)) / (1.0 - x);
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x):
	t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x))
	tmp = 0
	if t_0 <= 0.001:
		tmp = (3.0 + ((((2.0 + (-2.0 / x)) / x) - 2.0) / x)) / (1.0 - x)
	else:
		tmp = t_0
	return tmp
function code(x)
	t_0 = Float64(Float64(x / Float64(x + 1.0)) + Float64(Float64(x + 1.0) / Float64(1.0 - x)))
	tmp = 0.0
	if (t_0 <= 0.001)
		tmp = Float64(Float64(3.0 + Float64(Float64(Float64(Float64(2.0 + Float64(-2.0 / x)) / x) - 2.0) / x)) / Float64(1.0 - x));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x));
	tmp = 0.0;
	if (t_0 <= 0.001)
		tmp = (3.0 + ((((2.0 + (-2.0 / x)) / x) - 2.0) / x)) / (1.0 - x);
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] + N[(N[(x + 1.0), $MachinePrecision] / N[(1.0 - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 0.001], N[(N[(3.0 + N[(N[(N[(N[(2.0 + N[(-2.0 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision] - 2.0), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision] / N[(1.0 - x), $MachinePrecision]), $MachinePrecision], t$95$0]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x}{x + 1} + \frac{x + 1}{1 - x}\\
\mathbf{if}\;t\_0 \leq 0.001:\\
\;\;\;\;\frac{3 + \frac{\frac{2 + \frac{-2}{x}}{x} - 2}{x}}{1 - x}\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64)))) < 1e-3

    1. Initial program 7.9%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. remove-double-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
      2. distribute-neg-in7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
      3. sub-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
      4. distribute-frac-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
      5. distribute-frac-neg27.9%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
      6. sub-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
      7. +-commutative7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
      8. unsub-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
      9. metadata-eval7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
      10. neg-sub07.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
      11. associate-+l-7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
      12. neg-sub07.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
      13. +-commutative7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
      14. unsub-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
    3. Simplified7.9%

      \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. frac-2neg7.9%

        \[\leadsto \color{blue}{\frac{-x}{-\left(x + 1\right)}} - \frac{-1 - x}{1 - x} \]
      2. clear-num7.9%

        \[\leadsto \frac{-x}{-\left(x + 1\right)} - \color{blue}{\frac{1}{\frac{1 - x}{-1 - x}}} \]
      3. frac-sub8.0%

        \[\leadsto \color{blue}{\frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-\left(x + 1\right)\right) \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}}} \]
      4. +-commutative8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-\color{blue}{\left(1 + x\right)}\right) \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      5. distribute-neg-in8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \color{blue}{\left(\left(-1\right) + \left(-x\right)\right)} \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      6. metadata-eval8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(\color{blue}{-1} + \left(-x\right)\right) \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      7. sub-neg8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \color{blue}{\left(-1 - x\right)} \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      8. *-commutative8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \color{blue}{1 \cdot \left(-1 - x\right)}}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      9. *-un-lft-identity8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \color{blue}{\left(-1 - x\right)}}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      10. +-commutative8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\left(-\color{blue}{\left(1 + x\right)}\right) \cdot \frac{1 - x}{-1 - x}} \]
      11. distribute-neg-in8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{\left(\left(-1\right) + \left(-x\right)\right)} \cdot \frac{1 - x}{-1 - x}} \]
      12. metadata-eval8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\left(\color{blue}{-1} + \left(-x\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
      13. sub-neg8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{\left(-1 - x\right)} \cdot \frac{1 - x}{-1 - x}} \]
    6. Applied egg-rr8.0%

      \[\leadsto \color{blue}{\frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\left(-1 - x\right) \cdot \frac{1 - x}{-1 - x}}} \]
    7. Taylor expanded in x around 0 8.0%

      \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{1 + -1 \cdot x}} \]
    8. Step-by-step derivation
      1. mul-1-neg8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{1 + \color{blue}{\left(-x\right)}} \]
      2. unsub-neg8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{1 - x}} \]
    9. Simplified8.0%

      \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{1 - x}} \]
    10. Taylor expanded in x around -inf 99.5%

      \[\leadsto \frac{\color{blue}{3 + -1 \cdot \frac{2 + -1 \cdot \frac{2 - 2 \cdot \frac{1}{x}}{x}}{x}}}{1 - x} \]
    11. Step-by-step derivation
      1. mul-1-neg99.5%

        \[\leadsto \frac{3 + \color{blue}{\left(-\frac{2 + -1 \cdot \frac{2 - 2 \cdot \frac{1}{x}}{x}}{x}\right)}}{1 - x} \]
      2. unsub-neg99.5%

        \[\leadsto \frac{\color{blue}{3 - \frac{2 + -1 \cdot \frac{2 - 2 \cdot \frac{1}{x}}{x}}{x}}}{1 - x} \]
      3. mul-1-neg99.5%

        \[\leadsto \frac{3 - \frac{2 + \color{blue}{\left(-\frac{2 - 2 \cdot \frac{1}{x}}{x}\right)}}{x}}{1 - x} \]
      4. unsub-neg99.5%

        \[\leadsto \frac{3 - \frac{\color{blue}{2 - \frac{2 - 2 \cdot \frac{1}{x}}{x}}}{x}}{1 - x} \]
      5. sub-neg99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{\color{blue}{2 + \left(-2 \cdot \frac{1}{x}\right)}}{x}}{x}}{1 - x} \]
      6. associate-*r/99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{2 + \left(-\color{blue}{\frac{2 \cdot 1}{x}}\right)}{x}}{x}}{1 - x} \]
      7. metadata-eval99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{2 + \left(-\frac{\color{blue}{2}}{x}\right)}{x}}{x}}{1 - x} \]
      8. distribute-neg-frac99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{2 + \color{blue}{\frac{-2}{x}}}{x}}{x}}{1 - x} \]
      9. metadata-eval99.5%

        \[\leadsto \frac{3 - \frac{2 - \frac{2 + \frac{\color{blue}{-2}}{x}}{x}}{x}}{1 - x} \]
    12. Simplified99.5%

      \[\leadsto \frac{\color{blue}{3 - \frac{2 - \frac{2 + \frac{-2}{x}}{x}}{x}}}{1 - x} \]

    if 1e-3 < (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64))))

    1. Initial program 100.0%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Add Preprocessing
  3. Recombined 2 regimes into one program.
  4. Final simplification99.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{x + 1} + \frac{x + 1}{1 - x} \leq 0.001:\\ \;\;\;\;\frac{3 + \frac{\frac{2 + \frac{-2}{x}}{x} - 2}{x}}{1 - x}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{x + 1} + \frac{x + 1}{1 - x}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 99.8% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + 1} + \frac{x + 1}{1 - x}\\ \mathbf{if}\;t\_0 \leq 0.001:\\ \;\;\;\;\frac{\frac{-1 + \frac{-3 + \frac{-1}{x}}{x}}{x} - 3}{x}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (+ (/ x (+ x 1.0)) (/ (+ x 1.0) (- 1.0 x)))))
   (if (<= t_0 0.001)
     (/ (- (/ (+ -1.0 (/ (+ -3.0 (/ -1.0 x)) x)) x) 3.0) x)
     t_0)))
double code(double x) {
	double t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x));
	double tmp;
	if (t_0 <= 0.001) {
		tmp = (((-1.0 + ((-3.0 + (-1.0 / x)) / x)) / x) - 3.0) / x;
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (x / (x + 1.0d0)) + ((x + 1.0d0) / (1.0d0 - x))
    if (t_0 <= 0.001d0) then
        tmp = ((((-1.0d0) + (((-3.0d0) + ((-1.0d0) / x)) / x)) / x) - 3.0d0) / x
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x));
	double tmp;
	if (t_0 <= 0.001) {
		tmp = (((-1.0 + ((-3.0 + (-1.0 / x)) / x)) / x) - 3.0) / x;
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x):
	t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x))
	tmp = 0
	if t_0 <= 0.001:
		tmp = (((-1.0 + ((-3.0 + (-1.0 / x)) / x)) / x) - 3.0) / x
	else:
		tmp = t_0
	return tmp
function code(x)
	t_0 = Float64(Float64(x / Float64(x + 1.0)) + Float64(Float64(x + 1.0) / Float64(1.0 - x)))
	tmp = 0.0
	if (t_0 <= 0.001)
		tmp = Float64(Float64(Float64(Float64(-1.0 + Float64(Float64(-3.0 + Float64(-1.0 / x)) / x)) / x) - 3.0) / x);
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x));
	tmp = 0.0;
	if (t_0 <= 0.001)
		tmp = (((-1.0 + ((-3.0 + (-1.0 / x)) / x)) / x) - 3.0) / x;
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] + N[(N[(x + 1.0), $MachinePrecision] / N[(1.0 - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 0.001], N[(N[(N[(N[(-1.0 + N[(N[(-3.0 + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision] - 3.0), $MachinePrecision] / x), $MachinePrecision], t$95$0]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x}{x + 1} + \frac{x + 1}{1 - x}\\
\mathbf{if}\;t\_0 \leq 0.001:\\
\;\;\;\;\frac{\frac{-1 + \frac{-3 + \frac{-1}{x}}{x}}{x} - 3}{x}\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64)))) < 1e-3

    1. Initial program 7.9%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. remove-double-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
      2. distribute-neg-in7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
      3. sub-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
      4. distribute-frac-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
      5. distribute-frac-neg27.9%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
      6. sub-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
      7. +-commutative7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
      8. unsub-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
      9. metadata-eval7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
      10. neg-sub07.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
      11. associate-+l-7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
      12. neg-sub07.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
      13. +-commutative7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
      14. unsub-neg7.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
    3. Simplified7.9%

      \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 99.4%

      \[\leadsto \color{blue}{\frac{-1 \cdot \frac{3 + \frac{1}{x}}{{x}^{2}} - \left(3 + \frac{1}{x}\right)}{x}} \]
    6. Step-by-step derivation
      1. Simplified99.4%

        \[\leadsto \color{blue}{\frac{\frac{-1 + \frac{-3 + \frac{-1}{x}}{x}}{x} - 3}{x}} \]

      if 1e-3 < (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64))))

      1. Initial program 100.0%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Add Preprocessing
    7. Recombined 2 regimes into one program.
    8. Final simplification99.7%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{x + 1} + \frac{x + 1}{1 - x} \leq 0.001:\\ \;\;\;\;\frac{\frac{-1 + \frac{-3 + \frac{-1}{x}}{x}}{x} - 3}{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{x + 1} + \frac{x + 1}{1 - x}\\ \end{array} \]
    9. Add Preprocessing

    Alternative 5: 99.8% accurate, 0.4× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + 1} + \frac{x + 1}{1 - x}\\ \mathbf{if}\;t\_0 \leq 5 \cdot 10^{-5}:\\ \;\;\;\;\frac{-3 + \frac{-1 + \frac{-3}{x}}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (let* ((t_0 (+ (/ x (+ x 1.0)) (/ (+ x 1.0) (- 1.0 x)))))
       (if (<= t_0 5e-5) (/ (+ -3.0 (/ (+ -1.0 (/ -3.0 x)) x)) x) t_0)))
    double code(double x) {
    	double t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x));
    	double tmp;
    	if (t_0 <= 5e-5) {
    		tmp = (-3.0 + ((-1.0 + (-3.0 / x)) / x)) / x;
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        real(8) :: t_0
        real(8) :: tmp
        t_0 = (x / (x + 1.0d0)) + ((x + 1.0d0) / (1.0d0 - x))
        if (t_0 <= 5d-5) then
            tmp = ((-3.0d0) + (((-1.0d0) + ((-3.0d0) / x)) / x)) / x
        else
            tmp = t_0
        end if
        code = tmp
    end function
    
    public static double code(double x) {
    	double t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x));
    	double tmp;
    	if (t_0 <= 5e-5) {
    		tmp = (-3.0 + ((-1.0 + (-3.0 / x)) / x)) / x;
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    def code(x):
    	t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x))
    	tmp = 0
    	if t_0 <= 5e-5:
    		tmp = (-3.0 + ((-1.0 + (-3.0 / x)) / x)) / x
    	else:
    		tmp = t_0
    	return tmp
    
    function code(x)
    	t_0 = Float64(Float64(x / Float64(x + 1.0)) + Float64(Float64(x + 1.0) / Float64(1.0 - x)))
    	tmp = 0.0
    	if (t_0 <= 5e-5)
    		tmp = Float64(Float64(-3.0 + Float64(Float64(-1.0 + Float64(-3.0 / x)) / x)) / x);
    	else
    		tmp = t_0;
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	t_0 = (x / (x + 1.0)) + ((x + 1.0) / (1.0 - x));
    	tmp = 0.0;
    	if (t_0 <= 5e-5)
    		tmp = (-3.0 + ((-1.0 + (-3.0 / x)) / x)) / x;
    	else
    		tmp = t_0;
    	end
    	tmp_2 = tmp;
    end
    
    code[x_] := Block[{t$95$0 = N[(N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] + N[(N[(x + 1.0), $MachinePrecision] / N[(1.0 - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 5e-5], N[(N[(-3.0 + N[(N[(-1.0 + N[(-3.0 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision], t$95$0]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := \frac{x}{x + 1} + \frac{x + 1}{1 - x}\\
    \mathbf{if}\;t\_0 \leq 5 \cdot 10^{-5}:\\
    \;\;\;\;\frac{-3 + \frac{-1 + \frac{-3}{x}}{x}}{x}\\
    
    \mathbf{else}:\\
    \;\;\;\;t\_0\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64)))) < 5.00000000000000024e-5

      1. Initial program 7.3%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg7.3%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
        2. distribute-neg-in7.3%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
        3. sub-neg7.3%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
        4. distribute-frac-neg7.3%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
        5. distribute-frac-neg27.3%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg7.3%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative7.3%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg7.3%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval7.3%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub07.3%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-7.3%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub07.3%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative7.3%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg7.3%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified7.3%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around inf 99.4%

        \[\leadsto \color{blue}{\frac{-1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x} - 3}{x}} \]
      6. Step-by-step derivation
        1. sub-neg99.4%

          \[\leadsto \frac{\color{blue}{-1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x} + \left(-3\right)}}{x} \]
        2. metadata-eval99.4%

          \[\leadsto \frac{-1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x} + \color{blue}{-3}}{x} \]
        3. +-commutative99.4%

          \[\leadsto \frac{\color{blue}{-3 + -1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x}}}{x} \]
        4. associate-*r/99.4%

          \[\leadsto \frac{-3 + \color{blue}{\frac{-1 \cdot \left(1 + 3 \cdot \frac{1}{x}\right)}{x}}}{x} \]
        5. distribute-lft-in99.4%

          \[\leadsto \frac{-3 + \frac{\color{blue}{-1 \cdot 1 + -1 \cdot \left(3 \cdot \frac{1}{x}\right)}}{x}}{x} \]
        6. metadata-eval99.4%

          \[\leadsto \frac{-3 + \frac{\color{blue}{-1} + -1 \cdot \left(3 \cdot \frac{1}{x}\right)}{x}}{x} \]
        7. neg-mul-199.4%

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

          \[\leadsto \frac{-3 + \frac{-1 + \left(-\color{blue}{\frac{3 \cdot 1}{x}}\right)}{x}}{x} \]
        9. metadata-eval99.4%

          \[\leadsto \frac{-3 + \frac{-1 + \left(-\frac{\color{blue}{3}}{x}\right)}{x}}{x} \]
        10. distribute-neg-frac99.4%

          \[\leadsto \frac{-3 + \frac{-1 + \color{blue}{\frac{-3}{x}}}{x}}{x} \]
        11. metadata-eval99.4%

          \[\leadsto \frac{-3 + \frac{-1 + \frac{\color{blue}{-3}}{x}}{x}}{x} \]
      7. Simplified99.4%

        \[\leadsto \color{blue}{\frac{-3 + \frac{-1 + \frac{-3}{x}}{x}}{x}} \]

      if 5.00000000000000024e-5 < (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64))))

      1. Initial program 99.8%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Add Preprocessing
    3. Recombined 2 regimes into one program.
    4. Final simplification99.6%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{x + 1} + \frac{x + 1}{1 - x} \leq 5 \cdot 10^{-5}:\\ \;\;\;\;\frac{-3 + \frac{-1 + \frac{-3}{x}}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{x + 1} + \frac{x + 1}{1 - x}\\ \end{array} \]
    5. Add Preprocessing

    Alternative 6: 99.4% accurate, 0.6× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\ \;\;\;\;\frac{-3 + \frac{-1 + \frac{-3}{x}}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;1 + x \cdot \left(3 + x \cdot \left(1 + x \cdot 3\right)\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (or (<= x -1.0) (not (<= x 1.0)))
       (/ (+ -3.0 (/ (+ -1.0 (/ -3.0 x)) x)) x)
       (+ 1.0 (* x (+ 3.0 (* x (+ 1.0 (* x 3.0))))))))
    double code(double x) {
    	double tmp;
    	if ((x <= -1.0) || !(x <= 1.0)) {
    		tmp = (-3.0 + ((-1.0 + (-3.0 / x)) / x)) / x;
    	} else {
    		tmp = 1.0 + (x * (3.0 + (x * (1.0 + (x * 3.0)))));
    	}
    	return tmp;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        real(8) :: tmp
        if ((x <= (-1.0d0)) .or. (.not. (x <= 1.0d0))) then
            tmp = ((-3.0d0) + (((-1.0d0) + ((-3.0d0) / x)) / x)) / x
        else
            tmp = 1.0d0 + (x * (3.0d0 + (x * (1.0d0 + (x * 3.0d0)))))
        end if
        code = tmp
    end function
    
    public static double code(double x) {
    	double tmp;
    	if ((x <= -1.0) || !(x <= 1.0)) {
    		tmp = (-3.0 + ((-1.0 + (-3.0 / x)) / x)) / x;
    	} else {
    		tmp = 1.0 + (x * (3.0 + (x * (1.0 + (x * 3.0)))));
    	}
    	return tmp;
    }
    
    def code(x):
    	tmp = 0
    	if (x <= -1.0) or not (x <= 1.0):
    		tmp = (-3.0 + ((-1.0 + (-3.0 / x)) / x)) / x
    	else:
    		tmp = 1.0 + (x * (3.0 + (x * (1.0 + (x * 3.0)))))
    	return tmp
    
    function code(x)
    	tmp = 0.0
    	if ((x <= -1.0) || !(x <= 1.0))
    		tmp = Float64(Float64(-3.0 + Float64(Float64(-1.0 + Float64(-3.0 / x)) / x)) / x);
    	else
    		tmp = Float64(1.0 + Float64(x * Float64(3.0 + Float64(x * Float64(1.0 + Float64(x * 3.0))))));
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	tmp = 0.0;
    	if ((x <= -1.0) || ~((x <= 1.0)))
    		tmp = (-3.0 + ((-1.0 + (-3.0 / x)) / x)) / x;
    	else
    		tmp = 1.0 + (x * (3.0 + (x * (1.0 + (x * 3.0)))));
    	end
    	tmp_2 = tmp;
    end
    
    code[x_] := If[Or[LessEqual[x, -1.0], N[Not[LessEqual[x, 1.0]], $MachinePrecision]], N[(N[(-3.0 + N[(N[(-1.0 + N[(-3.0 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision], N[(1.0 + N[(x * N[(3.0 + N[(x * N[(1.0 + N[(x * 3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\
    \;\;\;\;\frac{-3 + \frac{-1 + \frac{-3}{x}}{x}}{x}\\
    
    \mathbf{else}:\\
    \;\;\;\;1 + x \cdot \left(3 + x \cdot \left(1 + x \cdot 3\right)\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if x < -1 or 1 < x

      1. Initial program 7.9%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
        2. distribute-neg-in7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
        3. sub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
        4. distribute-frac-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
        5. distribute-frac-neg27.9%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub07.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub07.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified7.9%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around inf 99.3%

        \[\leadsto \color{blue}{\frac{-1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x} - 3}{x}} \]
      6. Step-by-step derivation
        1. sub-neg99.3%

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

          \[\leadsto \frac{-1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x} + \color{blue}{-3}}{x} \]
        3. +-commutative99.3%

          \[\leadsto \frac{\color{blue}{-3 + -1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x}}}{x} \]
        4. associate-*r/99.3%

          \[\leadsto \frac{-3 + \color{blue}{\frac{-1 \cdot \left(1 + 3 \cdot \frac{1}{x}\right)}{x}}}{x} \]
        5. distribute-lft-in99.3%

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

          \[\leadsto \frac{-3 + \frac{\color{blue}{-1} + -1 \cdot \left(3 \cdot \frac{1}{x}\right)}{x}}{x} \]
        7. neg-mul-199.3%

          \[\leadsto \frac{-3 + \frac{-1 + \color{blue}{\left(-3 \cdot \frac{1}{x}\right)}}{x}}{x} \]
        8. associate-*r/99.3%

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

          \[\leadsto \frac{-3 + \frac{-1 + \left(-\frac{\color{blue}{3}}{x}\right)}{x}}{x} \]
        10. distribute-neg-frac99.3%

          \[\leadsto \frac{-3 + \frac{-1 + \color{blue}{\frac{-3}{x}}}{x}}{x} \]
        11. metadata-eval99.3%

          \[\leadsto \frac{-3 + \frac{-1 + \frac{\color{blue}{-3}}{x}}{x}}{x} \]
      7. Simplified99.3%

        \[\leadsto \color{blue}{\frac{-3 + \frac{-1 + \frac{-3}{x}}{x}}{x}} \]

      if -1 < x < 1

      1. Initial program 100.0%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
        2. distribute-neg-in100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
        3. sub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
        4. distribute-frac-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
        5. distribute-frac-neg2100.0%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub0100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub0100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified100.0%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 99.6%

        \[\leadsto \color{blue}{1 + x \cdot \left(3 + x \cdot \left(1 + 3 \cdot x\right)\right)} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification99.4%

      \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\ \;\;\;\;\frac{-3 + \frac{-1 + \frac{-3}{x}}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;1 + x \cdot \left(3 + x \cdot \left(1 + x \cdot 3\right)\right)\\ \end{array} \]
    5. Add Preprocessing

    Alternative 7: 99.3% accurate, 0.6× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\ \;\;\;\;\frac{-3 + \frac{-1 + \frac{-3}{x}}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;1 + x \cdot \left(x + 3\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (or (<= x -1.0) (not (<= x 1.0)))
       (/ (+ -3.0 (/ (+ -1.0 (/ -3.0 x)) x)) x)
       (+ 1.0 (* x (+ x 3.0)))))
    double code(double x) {
    	double tmp;
    	if ((x <= -1.0) || !(x <= 1.0)) {
    		tmp = (-3.0 + ((-1.0 + (-3.0 / x)) / x)) / x;
    	} else {
    		tmp = 1.0 + (x * (x + 3.0));
    	}
    	return tmp;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        real(8) :: tmp
        if ((x <= (-1.0d0)) .or. (.not. (x <= 1.0d0))) then
            tmp = ((-3.0d0) + (((-1.0d0) + ((-3.0d0) / x)) / x)) / x
        else
            tmp = 1.0d0 + (x * (x + 3.0d0))
        end if
        code = tmp
    end function
    
    public static double code(double x) {
    	double tmp;
    	if ((x <= -1.0) || !(x <= 1.0)) {
    		tmp = (-3.0 + ((-1.0 + (-3.0 / x)) / x)) / x;
    	} else {
    		tmp = 1.0 + (x * (x + 3.0));
    	}
    	return tmp;
    }
    
    def code(x):
    	tmp = 0
    	if (x <= -1.0) or not (x <= 1.0):
    		tmp = (-3.0 + ((-1.0 + (-3.0 / x)) / x)) / x
    	else:
    		tmp = 1.0 + (x * (x + 3.0))
    	return tmp
    
    function code(x)
    	tmp = 0.0
    	if ((x <= -1.0) || !(x <= 1.0))
    		tmp = Float64(Float64(-3.0 + Float64(Float64(-1.0 + Float64(-3.0 / x)) / x)) / x);
    	else
    		tmp = Float64(1.0 + Float64(x * Float64(x + 3.0)));
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	tmp = 0.0;
    	if ((x <= -1.0) || ~((x <= 1.0)))
    		tmp = (-3.0 + ((-1.0 + (-3.0 / x)) / x)) / x;
    	else
    		tmp = 1.0 + (x * (x + 3.0));
    	end
    	tmp_2 = tmp;
    end
    
    code[x_] := If[Or[LessEqual[x, -1.0], N[Not[LessEqual[x, 1.0]], $MachinePrecision]], N[(N[(-3.0 + N[(N[(-1.0 + N[(-3.0 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision], N[(1.0 + N[(x * N[(x + 3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\
    \;\;\;\;\frac{-3 + \frac{-1 + \frac{-3}{x}}{x}}{x}\\
    
    \mathbf{else}:\\
    \;\;\;\;1 + x \cdot \left(x + 3\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if x < -1 or 1 < x

      1. Initial program 7.9%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
        2. distribute-neg-in7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
        3. sub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
        4. distribute-frac-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
        5. distribute-frac-neg27.9%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub07.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub07.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified7.9%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around inf 99.3%

        \[\leadsto \color{blue}{\frac{-1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x} - 3}{x}} \]
      6. Step-by-step derivation
        1. sub-neg99.3%

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

          \[\leadsto \frac{-1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x} + \color{blue}{-3}}{x} \]
        3. +-commutative99.3%

          \[\leadsto \frac{\color{blue}{-3 + -1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x}}}{x} \]
        4. associate-*r/99.3%

          \[\leadsto \frac{-3 + \color{blue}{\frac{-1 \cdot \left(1 + 3 \cdot \frac{1}{x}\right)}{x}}}{x} \]
        5. distribute-lft-in99.3%

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

          \[\leadsto \frac{-3 + \frac{\color{blue}{-1} + -1 \cdot \left(3 \cdot \frac{1}{x}\right)}{x}}{x} \]
        7. neg-mul-199.3%

          \[\leadsto \frac{-3 + \frac{-1 + \color{blue}{\left(-3 \cdot \frac{1}{x}\right)}}{x}}{x} \]
        8. associate-*r/99.3%

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

          \[\leadsto \frac{-3 + \frac{-1 + \left(-\frac{\color{blue}{3}}{x}\right)}{x}}{x} \]
        10. distribute-neg-frac99.3%

          \[\leadsto \frac{-3 + \frac{-1 + \color{blue}{\frac{-3}{x}}}{x}}{x} \]
        11. metadata-eval99.3%

          \[\leadsto \frac{-3 + \frac{-1 + \frac{\color{blue}{-3}}{x}}{x}}{x} \]
      7. Simplified99.3%

        \[\leadsto \color{blue}{\frac{-3 + \frac{-1 + \frac{-3}{x}}{x}}{x}} \]

      if -1 < x < 1

      1. Initial program 100.0%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
        2. distribute-neg-in100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
        3. sub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
        4. distribute-frac-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
        5. distribute-frac-neg2100.0%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub0100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub0100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified100.0%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 99.4%

        \[\leadsto \color{blue}{1 + x \cdot \left(3 + x\right)} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification99.3%

      \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\ \;\;\;\;\frac{-3 + \frac{-1 + \frac{-3}{x}}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;1 + x \cdot \left(x + 3\right)\\ \end{array} \]
    5. Add Preprocessing

    Alternative 8: 99.1% accurate, 0.7× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 0.85\right):\\ \;\;\;\;\frac{3 - \frac{2}{x}}{1 - x}\\ \mathbf{else}:\\ \;\;\;\;1 + x \cdot \left(x + 3\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (or (<= x -1.0) (not (<= x 0.85)))
       (/ (- 3.0 (/ 2.0 x)) (- 1.0 x))
       (+ 1.0 (* x (+ x 3.0)))))
    double code(double x) {
    	double tmp;
    	if ((x <= -1.0) || !(x <= 0.85)) {
    		tmp = (3.0 - (2.0 / x)) / (1.0 - x);
    	} else {
    		tmp = 1.0 + (x * (x + 3.0));
    	}
    	return tmp;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        real(8) :: tmp
        if ((x <= (-1.0d0)) .or. (.not. (x <= 0.85d0))) then
            tmp = (3.0d0 - (2.0d0 / x)) / (1.0d0 - x)
        else
            tmp = 1.0d0 + (x * (x + 3.0d0))
        end if
        code = tmp
    end function
    
    public static double code(double x) {
    	double tmp;
    	if ((x <= -1.0) || !(x <= 0.85)) {
    		tmp = (3.0 - (2.0 / x)) / (1.0 - x);
    	} else {
    		tmp = 1.0 + (x * (x + 3.0));
    	}
    	return tmp;
    }
    
    def code(x):
    	tmp = 0
    	if (x <= -1.0) or not (x <= 0.85):
    		tmp = (3.0 - (2.0 / x)) / (1.0 - x)
    	else:
    		tmp = 1.0 + (x * (x + 3.0))
    	return tmp
    
    function code(x)
    	tmp = 0.0
    	if ((x <= -1.0) || !(x <= 0.85))
    		tmp = Float64(Float64(3.0 - Float64(2.0 / x)) / Float64(1.0 - x));
    	else
    		tmp = Float64(1.0 + Float64(x * Float64(x + 3.0)));
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	tmp = 0.0;
    	if ((x <= -1.0) || ~((x <= 0.85)))
    		tmp = (3.0 - (2.0 / x)) / (1.0 - x);
    	else
    		tmp = 1.0 + (x * (x + 3.0));
    	end
    	tmp_2 = tmp;
    end
    
    code[x_] := If[Or[LessEqual[x, -1.0], N[Not[LessEqual[x, 0.85]], $MachinePrecision]], N[(N[(3.0 - N[(2.0 / x), $MachinePrecision]), $MachinePrecision] / N[(1.0 - x), $MachinePrecision]), $MachinePrecision], N[(1.0 + N[(x * N[(x + 3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 0.85\right):\\
    \;\;\;\;\frac{3 - \frac{2}{x}}{1 - x}\\
    
    \mathbf{else}:\\
    \;\;\;\;1 + x \cdot \left(x + 3\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if x < -1 or 0.849999999999999978 < x

      1. Initial program 7.9%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
        2. distribute-neg-in7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
        3. sub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
        4. distribute-frac-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
        5. distribute-frac-neg27.9%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub07.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub07.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified7.9%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Step-by-step derivation
        1. frac-2neg7.9%

          \[\leadsto \color{blue}{\frac{-x}{-\left(x + 1\right)}} - \frac{-1 - x}{1 - x} \]
        2. clear-num7.9%

          \[\leadsto \frac{-x}{-\left(x + 1\right)} - \color{blue}{\frac{1}{\frac{1 - x}{-1 - x}}} \]
        3. frac-sub8.0%

          \[\leadsto \color{blue}{\frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-\left(x + 1\right)\right) \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}}} \]
        4. +-commutative8.0%

          \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-\color{blue}{\left(1 + x\right)}\right) \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
        5. distribute-neg-in8.0%

          \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \color{blue}{\left(\left(-1\right) + \left(-x\right)\right)} \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
        6. metadata-eval8.0%

          \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(\color{blue}{-1} + \left(-x\right)\right) \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
        7. sub-neg8.0%

          \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \color{blue}{\left(-1 - x\right)} \cdot 1}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
        8. *-commutative8.0%

          \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \color{blue}{1 \cdot \left(-1 - x\right)}}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
        9. *-un-lft-identity8.0%

          \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \color{blue}{\left(-1 - x\right)}}{\left(-\left(x + 1\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
        10. +-commutative8.0%

          \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\left(-\color{blue}{\left(1 + x\right)}\right) \cdot \frac{1 - x}{-1 - x}} \]
        11. distribute-neg-in8.0%

          \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{\left(\left(-1\right) + \left(-x\right)\right)} \cdot \frac{1 - x}{-1 - x}} \]
        12. metadata-eval8.0%

          \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\left(\color{blue}{-1} + \left(-x\right)\right) \cdot \frac{1 - x}{-1 - x}} \]
        13. sub-neg8.0%

          \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{\left(-1 - x\right)} \cdot \frac{1 - x}{-1 - x}} \]
      6. Applied egg-rr8.0%

        \[\leadsto \color{blue}{\frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\left(-1 - x\right) \cdot \frac{1 - x}{-1 - x}}} \]
      7. Taylor expanded in x around 0 8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{1 + -1 \cdot x}} \]
      8. Step-by-step derivation
        1. mul-1-neg8.0%

          \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{1 + \color{blue}{\left(-x\right)}} \]
        2. unsub-neg8.0%

          \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{1 - x}} \]
      9. Simplified8.0%

        \[\leadsto \frac{\left(-x\right) \cdot \frac{1 - x}{-1 - x} - \left(-1 - x\right)}{\color{blue}{1 - x}} \]
      10. Taylor expanded in x around inf 98.8%

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

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

          \[\leadsto \frac{3 - \frac{\color{blue}{2}}{x}}{1 - x} \]
      12. Simplified98.8%

        \[\leadsto \frac{\color{blue}{3 - \frac{2}{x}}}{1 - x} \]

      if -1 < x < 0.849999999999999978

      1. Initial program 100.0%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
        2. distribute-neg-in100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
        3. sub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
        4. distribute-frac-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
        5. distribute-frac-neg2100.0%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub0100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub0100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified100.0%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 99.4%

        \[\leadsto \color{blue}{1 + x \cdot \left(3 + x\right)} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification99.1%

      \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 0.85\right):\\ \;\;\;\;\frac{3 - \frac{2}{x}}{1 - x}\\ \mathbf{else}:\\ \;\;\;\;1 + x \cdot \left(x + 3\right)\\ \end{array} \]
    5. Add Preprocessing

    Alternative 9: 98.6% accurate, 0.8× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\ \;\;\;\;\frac{-3}{x}\\ \mathbf{else}:\\ \;\;\;\;1 + x \cdot \left(x + 3\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (or (<= x -1.0) (not (<= x 1.0))) (/ -3.0 x) (+ 1.0 (* x (+ x 3.0)))))
    double code(double x) {
    	double tmp;
    	if ((x <= -1.0) || !(x <= 1.0)) {
    		tmp = -3.0 / x;
    	} else {
    		tmp = 1.0 + (x * (x + 3.0));
    	}
    	return tmp;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        real(8) :: tmp
        if ((x <= (-1.0d0)) .or. (.not. (x <= 1.0d0))) then
            tmp = (-3.0d0) / x
        else
            tmp = 1.0d0 + (x * (x + 3.0d0))
        end if
        code = tmp
    end function
    
    public static double code(double x) {
    	double tmp;
    	if ((x <= -1.0) || !(x <= 1.0)) {
    		tmp = -3.0 / x;
    	} else {
    		tmp = 1.0 + (x * (x + 3.0));
    	}
    	return tmp;
    }
    
    def code(x):
    	tmp = 0
    	if (x <= -1.0) or not (x <= 1.0):
    		tmp = -3.0 / x
    	else:
    		tmp = 1.0 + (x * (x + 3.0))
    	return tmp
    
    function code(x)
    	tmp = 0.0
    	if ((x <= -1.0) || !(x <= 1.0))
    		tmp = Float64(-3.0 / x);
    	else
    		tmp = Float64(1.0 + Float64(x * Float64(x + 3.0)));
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	tmp = 0.0;
    	if ((x <= -1.0) || ~((x <= 1.0)))
    		tmp = -3.0 / x;
    	else
    		tmp = 1.0 + (x * (x + 3.0));
    	end
    	tmp_2 = tmp;
    end
    
    code[x_] := If[Or[LessEqual[x, -1.0], N[Not[LessEqual[x, 1.0]], $MachinePrecision]], N[(-3.0 / x), $MachinePrecision], N[(1.0 + N[(x * N[(x + 3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\
    \;\;\;\;\frac{-3}{x}\\
    
    \mathbf{else}:\\
    \;\;\;\;1 + x \cdot \left(x + 3\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if x < -1 or 1 < x

      1. Initial program 7.9%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
        2. distribute-neg-in7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
        3. sub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
        4. distribute-frac-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
        5. distribute-frac-neg27.9%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub07.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub07.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified7.9%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around inf 98.1%

        \[\leadsto \color{blue}{\frac{-3}{x}} \]

      if -1 < x < 1

      1. Initial program 100.0%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
        2. distribute-neg-in100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
        3. sub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
        4. distribute-frac-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
        5. distribute-frac-neg2100.0%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub0100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub0100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified100.0%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 99.4%

        \[\leadsto \color{blue}{1 + x \cdot \left(3 + x\right)} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification98.7%

      \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\ \;\;\;\;\frac{-3}{x}\\ \mathbf{else}:\\ \;\;\;\;1 + x \cdot \left(x + 3\right)\\ \end{array} \]
    5. Add Preprocessing

    Alternative 10: 99.1% accurate, 0.8× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\ \;\;\;\;\frac{-3 + \frac{-1}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;1 + x \cdot \left(x + 3\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (or (<= x -1.0) (not (<= x 1.0)))
       (/ (+ -3.0 (/ -1.0 x)) x)
       (+ 1.0 (* x (+ x 3.0)))))
    double code(double x) {
    	double tmp;
    	if ((x <= -1.0) || !(x <= 1.0)) {
    		tmp = (-3.0 + (-1.0 / x)) / x;
    	} else {
    		tmp = 1.0 + (x * (x + 3.0));
    	}
    	return tmp;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        real(8) :: tmp
        if ((x <= (-1.0d0)) .or. (.not. (x <= 1.0d0))) then
            tmp = ((-3.0d0) + ((-1.0d0) / x)) / x
        else
            tmp = 1.0d0 + (x * (x + 3.0d0))
        end if
        code = tmp
    end function
    
    public static double code(double x) {
    	double tmp;
    	if ((x <= -1.0) || !(x <= 1.0)) {
    		tmp = (-3.0 + (-1.0 / x)) / x;
    	} else {
    		tmp = 1.0 + (x * (x + 3.0));
    	}
    	return tmp;
    }
    
    def code(x):
    	tmp = 0
    	if (x <= -1.0) or not (x <= 1.0):
    		tmp = (-3.0 + (-1.0 / x)) / x
    	else:
    		tmp = 1.0 + (x * (x + 3.0))
    	return tmp
    
    function code(x)
    	tmp = 0.0
    	if ((x <= -1.0) || !(x <= 1.0))
    		tmp = Float64(Float64(-3.0 + Float64(-1.0 / x)) / x);
    	else
    		tmp = Float64(1.0 + Float64(x * Float64(x + 3.0)));
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	tmp = 0.0;
    	if ((x <= -1.0) || ~((x <= 1.0)))
    		tmp = (-3.0 + (-1.0 / x)) / x;
    	else
    		tmp = 1.0 + (x * (x + 3.0));
    	end
    	tmp_2 = tmp;
    end
    
    code[x_] := If[Or[LessEqual[x, -1.0], N[Not[LessEqual[x, 1.0]], $MachinePrecision]], N[(N[(-3.0 + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision], N[(1.0 + N[(x * N[(x + 3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\
    \;\;\;\;\frac{-3 + \frac{-1}{x}}{x}\\
    
    \mathbf{else}:\\
    \;\;\;\;1 + x \cdot \left(x + 3\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if x < -1 or 1 < x

      1. Initial program 7.9%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
        2. distribute-neg-in7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
        3. sub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
        4. distribute-frac-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
        5. distribute-frac-neg27.9%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub07.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub07.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified7.9%

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

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

          \[\leadsto \color{blue}{\frac{-1 \cdot \left(3 + \frac{1}{x}\right)}{x}} \]
        2. neg-mul-198.8%

          \[\leadsto \frac{\color{blue}{-\left(3 + \frac{1}{x}\right)}}{x} \]
        3. distribute-neg-in98.8%

          \[\leadsto \frac{\color{blue}{\left(-3\right) + \left(-\frac{1}{x}\right)}}{x} \]
        4. metadata-eval98.8%

          \[\leadsto \frac{\color{blue}{-3} + \left(-\frac{1}{x}\right)}{x} \]
        5. distribute-neg-frac98.8%

          \[\leadsto \frac{-3 + \color{blue}{\frac{-1}{x}}}{x} \]
        6. metadata-eval98.8%

          \[\leadsto \frac{-3 + \frac{\color{blue}{-1}}{x}}{x} \]
      7. Simplified98.8%

        \[\leadsto \color{blue}{\frac{-3 + \frac{-1}{x}}{x}} \]

      if -1 < x < 1

      1. Initial program 100.0%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
        2. distribute-neg-in100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
        3. sub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
        4. distribute-frac-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
        5. distribute-frac-neg2100.0%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub0100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub0100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified100.0%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 99.4%

        \[\leadsto \color{blue}{1 + x \cdot \left(3 + x\right)} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification99.1%

      \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\ \;\;\;\;\frac{-3 + \frac{-1}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;1 + x \cdot \left(x + 3\right)\\ \end{array} \]
    5. Add Preprocessing

    Alternative 11: 98.5% accurate, 0.9× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\ \;\;\;\;\frac{-3}{x}\\ \mathbf{else}:\\ \;\;\;\;1 + x \cdot 3\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (or (<= x -1.0) (not (<= x 1.0))) (/ -3.0 x) (+ 1.0 (* x 3.0))))
    double code(double x) {
    	double tmp;
    	if ((x <= -1.0) || !(x <= 1.0)) {
    		tmp = -3.0 / x;
    	} else {
    		tmp = 1.0 + (x * 3.0);
    	}
    	return tmp;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        real(8) :: tmp
        if ((x <= (-1.0d0)) .or. (.not. (x <= 1.0d0))) then
            tmp = (-3.0d0) / x
        else
            tmp = 1.0d0 + (x * 3.0d0)
        end if
        code = tmp
    end function
    
    public static double code(double x) {
    	double tmp;
    	if ((x <= -1.0) || !(x <= 1.0)) {
    		tmp = -3.0 / x;
    	} else {
    		tmp = 1.0 + (x * 3.0);
    	}
    	return tmp;
    }
    
    def code(x):
    	tmp = 0
    	if (x <= -1.0) or not (x <= 1.0):
    		tmp = -3.0 / x
    	else:
    		tmp = 1.0 + (x * 3.0)
    	return tmp
    
    function code(x)
    	tmp = 0.0
    	if ((x <= -1.0) || !(x <= 1.0))
    		tmp = Float64(-3.0 / x);
    	else
    		tmp = Float64(1.0 + Float64(x * 3.0));
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	tmp = 0.0;
    	if ((x <= -1.0) || ~((x <= 1.0)))
    		tmp = -3.0 / x;
    	else
    		tmp = 1.0 + (x * 3.0);
    	end
    	tmp_2 = tmp;
    end
    
    code[x_] := If[Or[LessEqual[x, -1.0], N[Not[LessEqual[x, 1.0]], $MachinePrecision]], N[(-3.0 / x), $MachinePrecision], N[(1.0 + N[(x * 3.0), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\
    \;\;\;\;\frac{-3}{x}\\
    
    \mathbf{else}:\\
    \;\;\;\;1 + x \cdot 3\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if x < -1 or 1 < x

      1. Initial program 7.9%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
        2. distribute-neg-in7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
        3. sub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
        4. distribute-frac-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
        5. distribute-frac-neg27.9%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub07.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub07.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified7.9%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around inf 98.1%

        \[\leadsto \color{blue}{\frac{-3}{x}} \]

      if -1 < x < 1

      1. Initial program 100.0%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
        2. distribute-neg-in100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
        3. sub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
        4. distribute-frac-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
        5. distribute-frac-neg2100.0%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub0100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub0100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified100.0%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 99.2%

        \[\leadsto \color{blue}{1 + 3 \cdot x} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification98.6%

      \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\ \;\;\;\;\frac{-3}{x}\\ \mathbf{else}:\\ \;\;\;\;1 + x \cdot 3\\ \end{array} \]
    5. Add Preprocessing

    Alternative 12: 97.9% accurate, 1.0× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\ \;\;\;\;\frac{-3}{x}\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (or (<= x -1.0) (not (<= x 1.0))) (/ -3.0 x) 1.0))
    double code(double x) {
    	double tmp;
    	if ((x <= -1.0) || !(x <= 1.0)) {
    		tmp = -3.0 / x;
    	} else {
    		tmp = 1.0;
    	}
    	return tmp;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        real(8) :: tmp
        if ((x <= (-1.0d0)) .or. (.not. (x <= 1.0d0))) then
            tmp = (-3.0d0) / x
        else
            tmp = 1.0d0
        end if
        code = tmp
    end function
    
    public static double code(double x) {
    	double tmp;
    	if ((x <= -1.0) || !(x <= 1.0)) {
    		tmp = -3.0 / x;
    	} else {
    		tmp = 1.0;
    	}
    	return tmp;
    }
    
    def code(x):
    	tmp = 0
    	if (x <= -1.0) or not (x <= 1.0):
    		tmp = -3.0 / x
    	else:
    		tmp = 1.0
    	return tmp
    
    function code(x)
    	tmp = 0.0
    	if ((x <= -1.0) || !(x <= 1.0))
    		tmp = Float64(-3.0 / x);
    	else
    		tmp = 1.0;
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	tmp = 0.0;
    	if ((x <= -1.0) || ~((x <= 1.0)))
    		tmp = -3.0 / x;
    	else
    		tmp = 1.0;
    	end
    	tmp_2 = tmp;
    end
    
    code[x_] := If[Or[LessEqual[x, -1.0], N[Not[LessEqual[x, 1.0]], $MachinePrecision]], N[(-3.0 / x), $MachinePrecision], 1.0]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\
    \;\;\;\;\frac{-3}{x}\\
    
    \mathbf{else}:\\
    \;\;\;\;1\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if x < -1 or 1 < x

      1. Initial program 7.9%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
        2. distribute-neg-in7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
        3. sub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
        4. distribute-frac-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
        5. distribute-frac-neg27.9%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub07.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub07.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg7.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified7.9%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around inf 98.1%

        \[\leadsto \color{blue}{\frac{-3}{x}} \]

      if -1 < x < 1

      1. Initial program 100.0%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
        2. distribute-neg-in100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
        3. sub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
        4. distribute-frac-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
        5. distribute-frac-neg2100.0%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub0100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub0100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg100.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified100.0%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 98.5%

        \[\leadsto \color{blue}{1} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification98.3%

      \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\ \;\;\;\;\frac{-3}{x}\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]
    5. Add Preprocessing

    Alternative 13: 50.7% accurate, 13.0× 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 53.9%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. remove-double-neg53.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
      2. distribute-neg-in53.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
      3. sub-neg53.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
      4. distribute-frac-neg53.9%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
      5. distribute-frac-neg253.9%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
      6. sub-neg53.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
      7. +-commutative53.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
      8. unsub-neg53.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
      9. metadata-eval53.9%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
      10. neg-sub053.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
      11. associate-+l-53.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
      12. neg-sub053.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
      13. +-commutative53.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
      14. unsub-neg53.9%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
    3. Simplified53.9%

      \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 51.1%

      \[\leadsto \color{blue}{1} \]
    6. Final simplification51.1%

      \[\leadsto 1 \]
    7. Add Preprocessing

    Reproduce

    ?
    herbie shell --seed 2024112 
    (FPCore (x)
      :name "Asymptote C"
      :precision binary64
      (- (/ x (+ x 1.0)) (/ (+ x 1.0) (- x 1.0))))