Asymptote C

Percentage Accurate: 53.7% → 99.8%
Time: 8.6s
Alternatives: 12
Speedup: 1.8×

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 12 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: 53.7% 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?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + 1} + \frac{-1 - x}{x + -1}\\ \mathbf{if}\;t_0 \leq 5 \cdot 10^{-5}:\\ \;\;\;\;\frac{-1}{{x}^{4}} + \left(\frac{-3 + \frac{-1}{x}}{x} + \frac{-3}{{x}^{3}}\right)\\ \mathbf{else}:\\ \;\;\;\;t_0\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (+ (/ x (+ x 1.0)) (/ (- -1.0 x) (+ x -1.0)))))
   (if (<= t_0 5e-5)
     (+
      (/ -1.0 (pow x 4.0))
      (+ (/ (+ -3.0 (/ -1.0 x)) x) (/ -3.0 (pow x 3.0))))
     t_0)))
double code(double x) {
	double t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0));
	double tmp;
	if (t_0 <= 5e-5) {
		tmp = (-1.0 / pow(x, 4.0)) + (((-3.0 + (-1.0 / x)) / x) + (-3.0 / pow(x, 3.0)));
	} 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)) + (((-1.0d0) - x) / (x + (-1.0d0)))
    if (t_0 <= 5d-5) then
        tmp = ((-1.0d0) / (x ** 4.0d0)) + ((((-3.0d0) + ((-1.0d0) / x)) / x) + ((-3.0d0) / (x ** 3.0d0)))
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0));
	double tmp;
	if (t_0 <= 5e-5) {
		tmp = (-1.0 / Math.pow(x, 4.0)) + (((-3.0 + (-1.0 / x)) / x) + (-3.0 / Math.pow(x, 3.0)));
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x):
	t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0))
	tmp = 0
	if t_0 <= 5e-5:
		tmp = (-1.0 / math.pow(x, 4.0)) + (((-3.0 + (-1.0 / x)) / x) + (-3.0 / math.pow(x, 3.0)))
	else:
		tmp = t_0
	return tmp
function code(x)
	t_0 = Float64(Float64(x / Float64(x + 1.0)) + Float64(Float64(-1.0 - x) / Float64(x + -1.0)))
	tmp = 0.0
	if (t_0 <= 5e-5)
		tmp = Float64(Float64(-1.0 / (x ^ 4.0)) + Float64(Float64(Float64(-3.0 + Float64(-1.0 / x)) / x) + Float64(-3.0 / (x ^ 3.0))));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0));
	tmp = 0.0;
	if (t_0 <= 5e-5)
		tmp = (-1.0 / (x ^ 4.0)) + (((-3.0 + (-1.0 / x)) / x) + (-3.0 / (x ^ 3.0)));
	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[(-1.0 - x), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 5e-5], N[(N[(-1.0 / N[Power[x, 4.0], $MachinePrecision]), $MachinePrecision] + N[(N[(N[(-3.0 + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision] + N[(-3.0 / N[Power[x, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$0]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x}{x + 1} + \frac{-1 - x}{x + -1}\\
\mathbf{if}\;t_0 \leq 5 \cdot 10^{-5}:\\
\;\;\;\;\frac{-1}{{x}^{4}} + \left(\frac{-3 + \frac{-1}{x}}{x} + \frac{-3}{{x}^{3}}\right)\\

\mathbf{else}:\\
\;\;\;\;t_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (/.f64 x (+.f64 x 1)) (/.f64 (+.f64 x 1) (-.f64 x 1))) < 5.00000000000000024e-5

    1. Initial program 9.1%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. clear-num9.1%

        \[\leadsto \color{blue}{\frac{1}{\frac{x + 1}{x}}} - \frac{x + 1}{x - 1} \]
      2. clear-num9.1%

        \[\leadsto \frac{1}{\frac{x + 1}{x}} - \color{blue}{\frac{1}{\frac{x - 1}{x + 1}}} \]
      3. frac-sub9.1%

        \[\leadsto \color{blue}{\frac{1 \cdot \frac{x - 1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}}} \]
      4. *-un-lft-identity9.1%

        \[\leadsto \frac{\color{blue}{\frac{x - 1}{x + 1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      5. sub-neg9.1%

        \[\leadsto \frac{\frac{\color{blue}{x + \left(-1\right)}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      6. metadata-eval9.1%

        \[\leadsto \frac{\frac{x + \color{blue}{-1}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      7. sub-neg9.1%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{\color{blue}{x + \left(-1\right)}}{x + 1}} \]
      8. metadata-eval9.1%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + \color{blue}{-1}}{x + 1}} \]
    3. Applied egg-rr9.1%

      \[\leadsto \color{blue}{\frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}} \]
    4. Step-by-step derivation
      1. clear-num9.1%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. metadata-eval9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{x + \color{blue}{\left(-1\right)}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      3. sub-neg9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{x - 1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      4. inv-pow9.1%

        \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x - 1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      5. sub-neg9.1%

        \[\leadsto \frac{{\left(\frac{x + 1}{\color{blue}{x + \left(-1\right)}}\right)}^{-1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      6. metadata-eval9.1%

        \[\leadsto \frac{{\left(\frac{x + 1}{x + \color{blue}{-1}}\right)}^{-1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    5. Applied egg-rr9.1%

      \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    6. Step-by-step derivation
      1. unpow-19.1%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. +-commutative9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    7. Simplified9.1%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    8. Taylor expanded in x around inf 98.5%

      \[\leadsto \color{blue}{-\left(\frac{1}{{x}^{4}} + \left(\frac{1}{{x}^{2}} + \left(3 \cdot \frac{1}{{x}^{3}} + 3 \cdot \frac{1}{x}\right)\right)\right)} \]
    9. Step-by-step derivation
      1. distribute-neg-in98.5%

        \[\leadsto \color{blue}{\left(-\frac{1}{{x}^{4}}\right) + \left(-\left(\frac{1}{{x}^{2}} + \left(3 \cdot \frac{1}{{x}^{3}} + 3 \cdot \frac{1}{x}\right)\right)\right)} \]
      2. distribute-neg-frac98.5%

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

        \[\leadsto \frac{\color{blue}{-1}}{{x}^{4}} + \left(-\left(\frac{1}{{x}^{2}} + \left(3 \cdot \frac{1}{{x}^{3}} + 3 \cdot \frac{1}{x}\right)\right)\right) \]
      4. +-commutative98.5%

        \[\leadsto \frac{-1}{{x}^{4}} + \left(-\left(\frac{1}{{x}^{2}} + \color{blue}{\left(3 \cdot \frac{1}{x} + 3 \cdot \frac{1}{{x}^{3}}\right)}\right)\right) \]
      5. associate-+r+98.5%

        \[\leadsto \frac{-1}{{x}^{4}} + \left(-\color{blue}{\left(\left(\frac{1}{{x}^{2}} + 3 \cdot \frac{1}{x}\right) + 3 \cdot \frac{1}{{x}^{3}}\right)}\right) \]
      6. distribute-neg-in98.5%

        \[\leadsto \frac{-1}{{x}^{4}} + \color{blue}{\left(\left(-\left(\frac{1}{{x}^{2}} + 3 \cdot \frac{1}{x}\right)\right) + \left(-3 \cdot \frac{1}{{x}^{3}}\right)\right)} \]
    10. Simplified99.0%

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

    if 5.00000000000000024e-5 < (-.f64 (/.f64 x (+.f64 x 1)) (/.f64 (+.f64 x 1) (-.f64 x 1)))

    1. Initial program 100.0%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{x + 1} + \frac{-1 - x}{x + -1} \leq 5 \cdot 10^{-5}:\\ \;\;\;\;\frac{-1}{{x}^{4}} + \left(\frac{-3 + \frac{-1}{x}}{x} + \frac{-3}{{x}^{3}}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{x + 1} + \frac{-1 - x}{x + -1}\\ \end{array} \]

Alternative 2: 99.8% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + 1}\\ t_1 := t_0 + \frac{-1 - x}{x + -1}\\ \mathbf{if}\;t_1 \leq 5 \cdot 10^{-5}:\\ \;\;\;\;\frac{\frac{\frac{2}{{x}^{3}} + \left(\frac{2}{x} + \left(-3 - \frac{2}{x \cdot x}\right)\right)}{t_0 \cdot \left(x + 1\right)}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}\\ \mathbf{else}:\\ \;\;\;\;t_1\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (/ x (+ x 1.0))) (t_1 (+ t_0 (/ (- -1.0 x) (+ x -1.0)))))
   (if (<= t_1 5e-5)
     (/
      (/
       (+ (/ 2.0 (pow x 3.0)) (+ (/ 2.0 x) (- -3.0 (/ 2.0 (* x x)))))
       (* t_0 (+ x 1.0)))
      (* (/ (+ x 1.0) x) (/ (+ x -1.0) (+ x 1.0))))
     t_1)))
double code(double x) {
	double t_0 = x / (x + 1.0);
	double t_1 = t_0 + ((-1.0 - x) / (x + -1.0));
	double tmp;
	if (t_1 <= 5e-5) {
		tmp = (((2.0 / pow(x, 3.0)) + ((2.0 / x) + (-3.0 - (2.0 / (x * x))))) / (t_0 * (x + 1.0))) / (((x + 1.0) / x) * ((x + -1.0) / (x + 1.0)));
	} else {
		tmp = t_1;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = x / (x + 1.0d0)
    t_1 = t_0 + (((-1.0d0) - x) / (x + (-1.0d0)))
    if (t_1 <= 5d-5) then
        tmp = (((2.0d0 / (x ** 3.0d0)) + ((2.0d0 / x) + ((-3.0d0) - (2.0d0 / (x * x))))) / (t_0 * (x + 1.0d0))) / (((x + 1.0d0) / x) * ((x + (-1.0d0)) / (x + 1.0d0)))
    else
        tmp = t_1
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = x / (x + 1.0);
	double t_1 = t_0 + ((-1.0 - x) / (x + -1.0));
	double tmp;
	if (t_1 <= 5e-5) {
		tmp = (((2.0 / Math.pow(x, 3.0)) + ((2.0 / x) + (-3.0 - (2.0 / (x * x))))) / (t_0 * (x + 1.0))) / (((x + 1.0) / x) * ((x + -1.0) / (x + 1.0)));
	} else {
		tmp = t_1;
	}
	return tmp;
}
def code(x):
	t_0 = x / (x + 1.0)
	t_1 = t_0 + ((-1.0 - x) / (x + -1.0))
	tmp = 0
	if t_1 <= 5e-5:
		tmp = (((2.0 / math.pow(x, 3.0)) + ((2.0 / x) + (-3.0 - (2.0 / (x * x))))) / (t_0 * (x + 1.0))) / (((x + 1.0) / x) * ((x + -1.0) / (x + 1.0)))
	else:
		tmp = t_1
	return tmp
function code(x)
	t_0 = Float64(x / Float64(x + 1.0))
	t_1 = Float64(t_0 + Float64(Float64(-1.0 - x) / Float64(x + -1.0)))
	tmp = 0.0
	if (t_1 <= 5e-5)
		tmp = Float64(Float64(Float64(Float64(2.0 / (x ^ 3.0)) + Float64(Float64(2.0 / x) + Float64(-3.0 - Float64(2.0 / Float64(x * x))))) / Float64(t_0 * Float64(x + 1.0))) / Float64(Float64(Float64(x + 1.0) / x) * Float64(Float64(x + -1.0) / Float64(x + 1.0))));
	else
		tmp = t_1;
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = x / (x + 1.0);
	t_1 = t_0 + ((-1.0 - x) / (x + -1.0));
	tmp = 0.0;
	if (t_1 <= 5e-5)
		tmp = (((2.0 / (x ^ 3.0)) + ((2.0 / x) + (-3.0 - (2.0 / (x * x))))) / (t_0 * (x + 1.0))) / (((x + 1.0) / x) * ((x + -1.0) / (x + 1.0)));
	else
		tmp = t_1;
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(t$95$0 + N[(N[(-1.0 - x), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, 5e-5], N[(N[(N[(N[(2.0 / N[Power[x, 3.0], $MachinePrecision]), $MachinePrecision] + N[(N[(2.0 / x), $MachinePrecision] + N[(-3.0 - N[(2.0 / N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(t$95$0 * N[(x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(x + 1.0), $MachinePrecision] / x), $MachinePrecision] * N[(N[(x + -1.0), $MachinePrecision] / N[(x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$1]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x}{x + 1}\\
t_1 := t_0 + \frac{-1 - x}{x + -1}\\
\mathbf{if}\;t_1 \leq 5 \cdot 10^{-5}:\\
\;\;\;\;\frac{\frac{\frac{2}{{x}^{3}} + \left(\frac{2}{x} + \left(-3 - \frac{2}{x \cdot x}\right)\right)}{t_0 \cdot \left(x + 1\right)}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}\\

\mathbf{else}:\\
\;\;\;\;t_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (/.f64 x (+.f64 x 1)) (/.f64 (+.f64 x 1) (-.f64 x 1))) < 5.00000000000000024e-5

    1. Initial program 9.1%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. clear-num9.1%

        \[\leadsto \color{blue}{\frac{1}{\frac{x + 1}{x}}} - \frac{x + 1}{x - 1} \]
      2. clear-num9.1%

        \[\leadsto \frac{1}{\frac{x + 1}{x}} - \color{blue}{\frac{1}{\frac{x - 1}{x + 1}}} \]
      3. frac-sub9.1%

        \[\leadsto \color{blue}{\frac{1 \cdot \frac{x - 1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}}} \]
      4. *-un-lft-identity9.1%

        \[\leadsto \frac{\color{blue}{\frac{x - 1}{x + 1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      5. sub-neg9.1%

        \[\leadsto \frac{\frac{\color{blue}{x + \left(-1\right)}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      6. metadata-eval9.1%

        \[\leadsto \frac{\frac{x + \color{blue}{-1}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      7. sub-neg9.1%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{\color{blue}{x + \left(-1\right)}}{x + 1}} \]
      8. metadata-eval9.1%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + \color{blue}{-1}}{x + 1}} \]
    3. Applied egg-rr9.1%

      \[\leadsto \color{blue}{\frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}} \]
    4. Step-by-step derivation
      1. clear-num9.1%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. metadata-eval9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{x + \color{blue}{\left(-1\right)}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      3. sub-neg9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{x - 1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      4. inv-pow9.1%

        \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x - 1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      5. sub-neg9.1%

        \[\leadsto \frac{{\left(\frac{x + 1}{\color{blue}{x + \left(-1\right)}}\right)}^{-1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      6. metadata-eval9.1%

        \[\leadsto \frac{{\left(\frac{x + 1}{x + \color{blue}{-1}}\right)}^{-1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    5. Applied egg-rr9.1%

      \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    6. Step-by-step derivation
      1. unpow-19.1%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. +-commutative9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    7. Simplified9.1%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    8. Step-by-step derivation
      1. +-commutative9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. clear-num9.1%

        \[\leadsto \frac{\color{blue}{\frac{x + -1}{x + 1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      3. *-rgt-identity9.1%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \color{blue}{\frac{x + 1}{x}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      4. clear-num9.1%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \color{blue}{\frac{1}{\frac{x}{x + 1}}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      5. frac-sub9.2%

        \[\leadsto \frac{\color{blue}{\frac{\left(x + -1\right) \cdot \frac{x}{x + 1} - \left(x + 1\right) \cdot 1}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      6. +-commutative9.2%

        \[\leadsto \frac{\frac{\left(x + -1\right) \cdot \frac{x}{\color{blue}{1 + x}} - \left(x + 1\right) \cdot 1}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      7. +-commutative9.2%

        \[\leadsto \frac{\frac{\left(x + -1\right) \cdot \frac{x}{1 + x} - \color{blue}{\left(1 + x\right)} \cdot 1}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      8. +-commutative9.2%

        \[\leadsto \frac{\frac{\left(x + -1\right) \cdot \frac{x}{1 + x} - \left(1 + x\right) \cdot 1}{\color{blue}{\left(1 + x\right)} \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      9. +-commutative9.2%

        \[\leadsto \frac{\frac{\left(x + -1\right) \cdot \frac{x}{1 + x} - \left(1 + x\right) \cdot 1}{\left(1 + x\right) \cdot \frac{x}{\color{blue}{1 + x}}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    9. Applied egg-rr9.2%

      \[\leadsto \frac{\color{blue}{\frac{\left(x + -1\right) \cdot \frac{x}{1 + x} - \left(1 + x\right) \cdot 1}{\left(1 + x\right) \cdot \frac{x}{1 + x}}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    10. Step-by-step derivation
      1. +-commutative9.2%

        \[\leadsto \frac{\frac{\color{blue}{\left(-1 + x\right)} \cdot \frac{x}{1 + x} - \left(1 + x\right) \cdot 1}{\left(1 + x\right) \cdot \frac{x}{1 + x}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. +-commutative9.2%

        \[\leadsto \frac{\frac{\left(-1 + x\right) \cdot \frac{x}{\color{blue}{x + 1}} - \left(1 + x\right) \cdot 1}{\left(1 + x\right) \cdot \frac{x}{1 + x}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      3. *-rgt-identity9.2%

        \[\leadsto \frac{\frac{\left(-1 + x\right) \cdot \frac{x}{x + 1} - \color{blue}{\left(1 + x\right)}}{\left(1 + x\right) \cdot \frac{x}{1 + x}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      4. +-commutative9.2%

        \[\leadsto \frac{\frac{\left(-1 + x\right) \cdot \frac{x}{x + 1} - \color{blue}{\left(x + 1\right)}}{\left(1 + x\right) \cdot \frac{x}{1 + x}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      5. +-commutative9.2%

        \[\leadsto \frac{\frac{\left(-1 + x\right) \cdot \frac{x}{x + 1} - \left(x + 1\right)}{\color{blue}{\left(x + 1\right)} \cdot \frac{x}{1 + x}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      6. +-commutative9.2%

        \[\leadsto \frac{\frac{\left(-1 + x\right) \cdot \frac{x}{x + 1} - \left(x + 1\right)}{\left(x + 1\right) \cdot \frac{x}{\color{blue}{x + 1}}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    11. Simplified9.2%

      \[\leadsto \frac{\color{blue}{\frac{\left(-1 + x\right) \cdot \frac{x}{x + 1} - \left(x + 1\right)}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    12. Taylor expanded in x around inf 99.0%

      \[\leadsto \frac{\frac{\color{blue}{\left(2 \cdot \frac{1}{x} + 2 \cdot \frac{1}{{x}^{3}}\right) - \left(3 + 2 \cdot \frac{1}{{x}^{2}}\right)}}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    13. Step-by-step derivation
      1. +-commutative99.0%

        \[\leadsto \frac{\frac{\color{blue}{\left(2 \cdot \frac{1}{{x}^{3}} + 2 \cdot \frac{1}{x}\right)} - \left(3 + 2 \cdot \frac{1}{{x}^{2}}\right)}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. associate--l+99.0%

        \[\leadsto \frac{\frac{\color{blue}{2 \cdot \frac{1}{{x}^{3}} + \left(2 \cdot \frac{1}{x} - \left(3 + 2 \cdot \frac{1}{{x}^{2}}\right)\right)}}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      3. associate-*r/99.0%

        \[\leadsto \frac{\frac{\color{blue}{\frac{2 \cdot 1}{{x}^{3}}} + \left(2 \cdot \frac{1}{x} - \left(3 + 2 \cdot \frac{1}{{x}^{2}}\right)\right)}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      4. metadata-eval99.0%

        \[\leadsto \frac{\frac{\frac{\color{blue}{2}}{{x}^{3}} + \left(2 \cdot \frac{1}{x} - \left(3 + 2 \cdot \frac{1}{{x}^{2}}\right)\right)}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      5. associate--r+99.0%

        \[\leadsto \frac{\frac{\frac{2}{{x}^{3}} + \color{blue}{\left(\left(2 \cdot \frac{1}{x} - 3\right) - 2 \cdot \frac{1}{{x}^{2}}\right)}}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      6. sub-neg99.0%

        \[\leadsto \frac{\frac{\frac{2}{{x}^{3}} + \left(\color{blue}{\left(2 \cdot \frac{1}{x} + \left(-3\right)\right)} - 2 \cdot \frac{1}{{x}^{2}}\right)}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      7. metadata-eval99.0%

        \[\leadsto \frac{\frac{\frac{2}{{x}^{3}} + \left(\left(2 \cdot \frac{1}{x} + \color{blue}{-3}\right) - 2 \cdot \frac{1}{{x}^{2}}\right)}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      8. associate--l+99.0%

        \[\leadsto \frac{\frac{\frac{2}{{x}^{3}} + \color{blue}{\left(2 \cdot \frac{1}{x} + \left(-3 - 2 \cdot \frac{1}{{x}^{2}}\right)\right)}}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      9. associate-*r/99.0%

        \[\leadsto \frac{\frac{\frac{2}{{x}^{3}} + \left(\color{blue}{\frac{2 \cdot 1}{x}} + \left(-3 - 2 \cdot \frac{1}{{x}^{2}}\right)\right)}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      10. metadata-eval99.0%

        \[\leadsto \frac{\frac{\frac{2}{{x}^{3}} + \left(\frac{\color{blue}{2}}{x} + \left(-3 - 2 \cdot \frac{1}{{x}^{2}}\right)\right)}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      11. associate-*r/99.0%

        \[\leadsto \frac{\frac{\frac{2}{{x}^{3}} + \left(\frac{2}{x} + \left(-3 - \color{blue}{\frac{2 \cdot 1}{{x}^{2}}}\right)\right)}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      12. metadata-eval99.0%

        \[\leadsto \frac{\frac{\frac{2}{{x}^{3}} + \left(\frac{2}{x} + \left(-3 - \frac{\color{blue}{2}}{{x}^{2}}\right)\right)}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      13. unpow299.0%

        \[\leadsto \frac{\frac{\frac{2}{{x}^{3}} + \left(\frac{2}{x} + \left(-3 - \frac{2}{\color{blue}{x \cdot x}}\right)\right)}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    14. Simplified99.0%

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

    if 5.00000000000000024e-5 < (-.f64 (/.f64 x (+.f64 x 1)) (/.f64 (+.f64 x 1) (-.f64 x 1)))

    1. Initial program 100.0%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{x + 1} + \frac{-1 - x}{x + -1} \leq 5 \cdot 10^{-5}:\\ \;\;\;\;\frac{\frac{\frac{2}{{x}^{3}} + \left(\frac{2}{x} + \left(-3 - \frac{2}{x \cdot x}\right)\right)}{\frac{x}{x + 1} \cdot \left(x + 1\right)}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{x + 1} + \frac{-1 - x}{x + -1}\\ \end{array} \]

Alternative 3: 99.8% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + 1} + \frac{-1 - x}{x + -1}\\ \mathbf{if}\;t_0 \leq 5 \cdot 10^{-5}:\\ \;\;\;\;\frac{-3 + \frac{-1}{x}}{x} + \frac{-3}{{x}^{3}}\\ \mathbf{else}:\\ \;\;\;\;t_0\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (+ (/ x (+ x 1.0)) (/ (- -1.0 x) (+ x -1.0)))))
   (if (<= t_0 5e-5) (+ (/ (+ -3.0 (/ -1.0 x)) x) (/ -3.0 (pow x 3.0))) t_0)))
double code(double x) {
	double t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0));
	double tmp;
	if (t_0 <= 5e-5) {
		tmp = ((-3.0 + (-1.0 / x)) / x) + (-3.0 / pow(x, 3.0));
	} 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)) + (((-1.0d0) - x) / (x + (-1.0d0)))
    if (t_0 <= 5d-5) then
        tmp = (((-3.0d0) + ((-1.0d0) / x)) / x) + ((-3.0d0) / (x ** 3.0d0))
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0));
	double tmp;
	if (t_0 <= 5e-5) {
		tmp = ((-3.0 + (-1.0 / x)) / x) + (-3.0 / Math.pow(x, 3.0));
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x):
	t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0))
	tmp = 0
	if t_0 <= 5e-5:
		tmp = ((-3.0 + (-1.0 / x)) / x) + (-3.0 / math.pow(x, 3.0))
	else:
		tmp = t_0
	return tmp
function code(x)
	t_0 = Float64(Float64(x / Float64(x + 1.0)) + Float64(Float64(-1.0 - x) / Float64(x + -1.0)))
	tmp = 0.0
	if (t_0 <= 5e-5)
		tmp = Float64(Float64(Float64(-3.0 + Float64(-1.0 / x)) / x) + Float64(-3.0 / (x ^ 3.0)));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0));
	tmp = 0.0;
	if (t_0 <= 5e-5)
		tmp = ((-3.0 + (-1.0 / x)) / x) + (-3.0 / (x ^ 3.0));
	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[(-1.0 - x), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 5e-5], N[(N[(N[(-3.0 + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision] + N[(-3.0 / N[Power[x, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$0]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x}{x + 1} + \frac{-1 - x}{x + -1}\\
\mathbf{if}\;t_0 \leq 5 \cdot 10^{-5}:\\
\;\;\;\;\frac{-3 + \frac{-1}{x}}{x} + \frac{-3}{{x}^{3}}\\

\mathbf{else}:\\
\;\;\;\;t_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (/.f64 x (+.f64 x 1)) (/.f64 (+.f64 x 1) (-.f64 x 1))) < 5.00000000000000024e-5

    1. Initial program 9.1%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. clear-num9.1%

        \[\leadsto \color{blue}{\frac{1}{\frac{x + 1}{x}}} - \frac{x + 1}{x - 1} \]
      2. clear-num9.1%

        \[\leadsto \frac{1}{\frac{x + 1}{x}} - \color{blue}{\frac{1}{\frac{x - 1}{x + 1}}} \]
      3. frac-sub9.1%

        \[\leadsto \color{blue}{\frac{1 \cdot \frac{x - 1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}}} \]
      4. *-un-lft-identity9.1%

        \[\leadsto \frac{\color{blue}{\frac{x - 1}{x + 1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      5. sub-neg9.1%

        \[\leadsto \frac{\frac{\color{blue}{x + \left(-1\right)}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      6. metadata-eval9.1%

        \[\leadsto \frac{\frac{x + \color{blue}{-1}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      7. sub-neg9.1%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{\color{blue}{x + \left(-1\right)}}{x + 1}} \]
      8. metadata-eval9.1%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + \color{blue}{-1}}{x + 1}} \]
    3. Applied egg-rr9.1%

      \[\leadsto \color{blue}{\frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}} \]
    4. Step-by-step derivation
      1. clear-num9.1%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. metadata-eval9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{x + \color{blue}{\left(-1\right)}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      3. sub-neg9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{x - 1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      4. inv-pow9.1%

        \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x - 1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      5. sub-neg9.1%

        \[\leadsto \frac{{\left(\frac{x + 1}{\color{blue}{x + \left(-1\right)}}\right)}^{-1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      6. metadata-eval9.1%

        \[\leadsto \frac{{\left(\frac{x + 1}{x + \color{blue}{-1}}\right)}^{-1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    5. Applied egg-rr9.1%

      \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    6. Step-by-step derivation
      1. unpow-19.1%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. +-commutative9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    7. Simplified9.1%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    8. Taylor expanded in x around inf 98.3%

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

        \[\leadsto -\color{blue}{\left(\left(\frac{1}{{x}^{2}} + 3 \cdot \frac{1}{x}\right) + 3 \cdot \frac{1}{{x}^{3}}\right)} \]
      2. distribute-neg-in98.3%

        \[\leadsto \color{blue}{\left(-\left(\frac{1}{{x}^{2}} + 3 \cdot \frac{1}{x}\right)\right) + \left(-3 \cdot \frac{1}{{x}^{3}}\right)} \]
      3. neg-sub098.3%

        \[\leadsto \color{blue}{\left(0 - \left(\frac{1}{{x}^{2}} + 3 \cdot \frac{1}{x}\right)\right)} + \left(-3 \cdot \frac{1}{{x}^{3}}\right) \]
      4. +-commutative98.3%

        \[\leadsto \left(0 - \color{blue}{\left(3 \cdot \frac{1}{x} + \frac{1}{{x}^{2}}\right)}\right) + \left(-3 \cdot \frac{1}{{x}^{3}}\right) \]
      5. associate--r+98.3%

        \[\leadsto \color{blue}{\left(\left(0 - 3 \cdot \frac{1}{x}\right) - \frac{1}{{x}^{2}}\right)} + \left(-3 \cdot \frac{1}{{x}^{3}}\right) \]
      6. neg-sub098.3%

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

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

        \[\leadsto \left(\left(-\frac{\color{blue}{3}}{x}\right) - \frac{1}{{x}^{2}}\right) + \left(-3 \cdot \frac{1}{{x}^{3}}\right) \]
      9. distribute-neg-frac98.8%

        \[\leadsto \left(\color{blue}{\frac{-3}{x}} - \frac{1}{{x}^{2}}\right) + \left(-3 \cdot \frac{1}{{x}^{3}}\right) \]
      10. metadata-eval98.8%

        \[\leadsto \left(\frac{\color{blue}{-3}}{x} - \frac{1}{{x}^{2}}\right) + \left(-3 \cdot \frac{1}{{x}^{3}}\right) \]
      11. unpow298.8%

        \[\leadsto \left(\frac{-3}{x} - \frac{1}{\color{blue}{x \cdot x}}\right) + \left(-3 \cdot \frac{1}{{x}^{3}}\right) \]
      12. associate-/r*98.8%

        \[\leadsto \left(\frac{-3}{x} - \color{blue}{\frac{\frac{1}{x}}{x}}\right) + \left(-3 \cdot \frac{1}{{x}^{3}}\right) \]
      13. div-sub98.8%

        \[\leadsto \color{blue}{\frac{-3 - \frac{1}{x}}{x}} + \left(-3 \cdot \frac{1}{{x}^{3}}\right) \]
      14. associate-*r/98.8%

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

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

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

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

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

    if 5.00000000000000024e-5 < (-.f64 (/.f64 x (+.f64 x 1)) (/.f64 (+.f64 x 1) (-.f64 x 1)))

    1. Initial program 100.0%

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

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

Alternative 4: 99.8% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + 1}\\ t_1 := t_0 + \frac{-1 - x}{x + -1}\\ \mathbf{if}\;t_1 \leq 5 \cdot 10^{-5}:\\ \;\;\;\;\frac{\frac{\left(-3 + \frac{2}{x}\right) - \frac{2}{x \cdot x}}{t_0 \cdot \left(x + 1\right)}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}\\ \mathbf{else}:\\ \;\;\;\;t_1\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (/ x (+ x 1.0))) (t_1 (+ t_0 (/ (- -1.0 x) (+ x -1.0)))))
   (if (<= t_1 5e-5)
     (/
      (/ (- (+ -3.0 (/ 2.0 x)) (/ 2.0 (* x x))) (* t_0 (+ x 1.0)))
      (* (/ (+ x 1.0) x) (/ (+ x -1.0) (+ x 1.0))))
     t_1)))
double code(double x) {
	double t_0 = x / (x + 1.0);
	double t_1 = t_0 + ((-1.0 - x) / (x + -1.0));
	double tmp;
	if (t_1 <= 5e-5) {
		tmp = (((-3.0 + (2.0 / x)) - (2.0 / (x * x))) / (t_0 * (x + 1.0))) / (((x + 1.0) / x) * ((x + -1.0) / (x + 1.0)));
	} else {
		tmp = t_1;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = x / (x + 1.0d0)
    t_1 = t_0 + (((-1.0d0) - x) / (x + (-1.0d0)))
    if (t_1 <= 5d-5) then
        tmp = ((((-3.0d0) + (2.0d0 / x)) - (2.0d0 / (x * x))) / (t_0 * (x + 1.0d0))) / (((x + 1.0d0) / x) * ((x + (-1.0d0)) / (x + 1.0d0)))
    else
        tmp = t_1
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = x / (x + 1.0);
	double t_1 = t_0 + ((-1.0 - x) / (x + -1.0));
	double tmp;
	if (t_1 <= 5e-5) {
		tmp = (((-3.0 + (2.0 / x)) - (2.0 / (x * x))) / (t_0 * (x + 1.0))) / (((x + 1.0) / x) * ((x + -1.0) / (x + 1.0)));
	} else {
		tmp = t_1;
	}
	return tmp;
}
def code(x):
	t_0 = x / (x + 1.0)
	t_1 = t_0 + ((-1.0 - x) / (x + -1.0))
	tmp = 0
	if t_1 <= 5e-5:
		tmp = (((-3.0 + (2.0 / x)) - (2.0 / (x * x))) / (t_0 * (x + 1.0))) / (((x + 1.0) / x) * ((x + -1.0) / (x + 1.0)))
	else:
		tmp = t_1
	return tmp
function code(x)
	t_0 = Float64(x / Float64(x + 1.0))
	t_1 = Float64(t_0 + Float64(Float64(-1.0 - x) / Float64(x + -1.0)))
	tmp = 0.0
	if (t_1 <= 5e-5)
		tmp = Float64(Float64(Float64(Float64(-3.0 + Float64(2.0 / x)) - Float64(2.0 / Float64(x * x))) / Float64(t_0 * Float64(x + 1.0))) / Float64(Float64(Float64(x + 1.0) / x) * Float64(Float64(x + -1.0) / Float64(x + 1.0))));
	else
		tmp = t_1;
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = x / (x + 1.0);
	t_1 = t_0 + ((-1.0 - x) / (x + -1.0));
	tmp = 0.0;
	if (t_1 <= 5e-5)
		tmp = (((-3.0 + (2.0 / x)) - (2.0 / (x * x))) / (t_0 * (x + 1.0))) / (((x + 1.0) / x) * ((x + -1.0) / (x + 1.0)));
	else
		tmp = t_1;
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(t$95$0 + N[(N[(-1.0 - x), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, 5e-5], N[(N[(N[(N[(-3.0 + N[(2.0 / x), $MachinePrecision]), $MachinePrecision] - N[(2.0 / N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(t$95$0 * N[(x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(x + 1.0), $MachinePrecision] / x), $MachinePrecision] * N[(N[(x + -1.0), $MachinePrecision] / N[(x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$1]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x}{x + 1}\\
t_1 := t_0 + \frac{-1 - x}{x + -1}\\
\mathbf{if}\;t_1 \leq 5 \cdot 10^{-5}:\\
\;\;\;\;\frac{\frac{\left(-3 + \frac{2}{x}\right) - \frac{2}{x \cdot x}}{t_0 \cdot \left(x + 1\right)}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}\\

\mathbf{else}:\\
\;\;\;\;t_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (/.f64 x (+.f64 x 1)) (/.f64 (+.f64 x 1) (-.f64 x 1))) < 5.00000000000000024e-5

    1. Initial program 9.1%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. clear-num9.1%

        \[\leadsto \color{blue}{\frac{1}{\frac{x + 1}{x}}} - \frac{x + 1}{x - 1} \]
      2. clear-num9.1%

        \[\leadsto \frac{1}{\frac{x + 1}{x}} - \color{blue}{\frac{1}{\frac{x - 1}{x + 1}}} \]
      3. frac-sub9.1%

        \[\leadsto \color{blue}{\frac{1 \cdot \frac{x - 1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}}} \]
      4. *-un-lft-identity9.1%

        \[\leadsto \frac{\color{blue}{\frac{x - 1}{x + 1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      5. sub-neg9.1%

        \[\leadsto \frac{\frac{\color{blue}{x + \left(-1\right)}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      6. metadata-eval9.1%

        \[\leadsto \frac{\frac{x + \color{blue}{-1}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      7. sub-neg9.1%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{\color{blue}{x + \left(-1\right)}}{x + 1}} \]
      8. metadata-eval9.1%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + \color{blue}{-1}}{x + 1}} \]
    3. Applied egg-rr9.1%

      \[\leadsto \color{blue}{\frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}} \]
    4. Step-by-step derivation
      1. clear-num9.1%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. metadata-eval9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{x + \color{blue}{\left(-1\right)}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      3. sub-neg9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{x - 1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      4. inv-pow9.1%

        \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x - 1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      5. sub-neg9.1%

        \[\leadsto \frac{{\left(\frac{x + 1}{\color{blue}{x + \left(-1\right)}}\right)}^{-1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      6. metadata-eval9.1%

        \[\leadsto \frac{{\left(\frac{x + 1}{x + \color{blue}{-1}}\right)}^{-1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    5. Applied egg-rr9.1%

      \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    6. Step-by-step derivation
      1. unpow-19.1%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. +-commutative9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    7. Simplified9.1%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    8. Step-by-step derivation
      1. +-commutative9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. clear-num9.1%

        \[\leadsto \frac{\color{blue}{\frac{x + -1}{x + 1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      3. *-rgt-identity9.1%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \color{blue}{\frac{x + 1}{x}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      4. clear-num9.1%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \color{blue}{\frac{1}{\frac{x}{x + 1}}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      5. frac-sub9.2%

        \[\leadsto \frac{\color{blue}{\frac{\left(x + -1\right) \cdot \frac{x}{x + 1} - \left(x + 1\right) \cdot 1}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      6. +-commutative9.2%

        \[\leadsto \frac{\frac{\left(x + -1\right) \cdot \frac{x}{\color{blue}{1 + x}} - \left(x + 1\right) \cdot 1}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      7. +-commutative9.2%

        \[\leadsto \frac{\frac{\left(x + -1\right) \cdot \frac{x}{1 + x} - \color{blue}{\left(1 + x\right)} \cdot 1}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      8. +-commutative9.2%

        \[\leadsto \frac{\frac{\left(x + -1\right) \cdot \frac{x}{1 + x} - \left(1 + x\right) \cdot 1}{\color{blue}{\left(1 + x\right)} \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      9. +-commutative9.2%

        \[\leadsto \frac{\frac{\left(x + -1\right) \cdot \frac{x}{1 + x} - \left(1 + x\right) \cdot 1}{\left(1 + x\right) \cdot \frac{x}{\color{blue}{1 + x}}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    9. Applied egg-rr9.2%

      \[\leadsto \frac{\color{blue}{\frac{\left(x + -1\right) \cdot \frac{x}{1 + x} - \left(1 + x\right) \cdot 1}{\left(1 + x\right) \cdot \frac{x}{1 + x}}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    10. Step-by-step derivation
      1. +-commutative9.2%

        \[\leadsto \frac{\frac{\color{blue}{\left(-1 + x\right)} \cdot \frac{x}{1 + x} - \left(1 + x\right) \cdot 1}{\left(1 + x\right) \cdot \frac{x}{1 + x}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. +-commutative9.2%

        \[\leadsto \frac{\frac{\left(-1 + x\right) \cdot \frac{x}{\color{blue}{x + 1}} - \left(1 + x\right) \cdot 1}{\left(1 + x\right) \cdot \frac{x}{1 + x}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      3. *-rgt-identity9.2%

        \[\leadsto \frac{\frac{\left(-1 + x\right) \cdot \frac{x}{x + 1} - \color{blue}{\left(1 + x\right)}}{\left(1 + x\right) \cdot \frac{x}{1 + x}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      4. +-commutative9.2%

        \[\leadsto \frac{\frac{\left(-1 + x\right) \cdot \frac{x}{x + 1} - \color{blue}{\left(x + 1\right)}}{\left(1 + x\right) \cdot \frac{x}{1 + x}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      5. +-commutative9.2%

        \[\leadsto \frac{\frac{\left(-1 + x\right) \cdot \frac{x}{x + 1} - \left(x + 1\right)}{\color{blue}{\left(x + 1\right)} \cdot \frac{x}{1 + x}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      6. +-commutative9.2%

        \[\leadsto \frac{\frac{\left(-1 + x\right) \cdot \frac{x}{x + 1} - \left(x + 1\right)}{\left(x + 1\right) \cdot \frac{x}{\color{blue}{x + 1}}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    11. Simplified9.2%

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

      \[\leadsto \frac{\frac{\color{blue}{2 \cdot \frac{1}{x} - \left(3 + 2 \cdot \frac{1}{{x}^{2}}\right)}}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    13. Step-by-step derivation
      1. associate--r+98.8%

        \[\leadsto \frac{\frac{\color{blue}{\left(2 \cdot \frac{1}{x} - 3\right) - 2 \cdot \frac{1}{{x}^{2}}}}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. sub-neg98.8%

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

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

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

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

        \[\leadsto \frac{\frac{\left(\frac{2}{x} + -3\right) - \color{blue}{\frac{2 \cdot 1}{{x}^{2}}}}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      7. metadata-eval98.8%

        \[\leadsto \frac{\frac{\left(\frac{2}{x} + -3\right) - \frac{\color{blue}{2}}{{x}^{2}}}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      8. unpow298.8%

        \[\leadsto \frac{\frac{\left(\frac{2}{x} + -3\right) - \frac{2}{\color{blue}{x \cdot x}}}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    14. Simplified98.8%

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

    if 5.00000000000000024e-5 < (-.f64 (/.f64 x (+.f64 x 1)) (/.f64 (+.f64 x 1) (-.f64 x 1)))

    1. Initial program 100.0%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{x + 1} + \frac{-1 - x}{x + -1} \leq 5 \cdot 10^{-5}:\\ \;\;\;\;\frac{\frac{\left(-3 + \frac{2}{x}\right) - \frac{2}{x \cdot x}}{\frac{x}{x + 1} \cdot \left(x + 1\right)}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{x + 1} + \frac{-1 - x}{x + -1}\\ \end{array} \]

Alternative 5: 99.6% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{x}{x + 1} + \frac{-1 - x}{x + -1} \leq 2 \cdot 10^{-8}:\\ \;\;\;\;\frac{-3 + \frac{-1}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{x \cdot \left(x + -1\right) - \left(x + 1\right) \cdot \left(x + 1\right)}{x \cdot \left(x + 1\right)}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= (+ (/ x (+ x 1.0)) (/ (- -1.0 x) (+ x -1.0))) 2e-8)
   (/ (+ -3.0 (/ -1.0 x)) x)
   (/
    (/ (- (* x (+ x -1.0)) (* (+ x 1.0) (+ x 1.0))) (* x (+ x 1.0)))
    (* (/ (+ x 1.0) x) (/ (+ x -1.0) (+ x 1.0))))))
double code(double x) {
	double tmp;
	if (((x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0))) <= 2e-8) {
		tmp = (-3.0 + (-1.0 / x)) / x;
	} else {
		tmp = (((x * (x + -1.0)) - ((x + 1.0) * (x + 1.0))) / (x * (x + 1.0))) / (((x + 1.0) / x) * ((x + -1.0) / (x + 1.0)));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (((x / (x + 1.0d0)) + (((-1.0d0) - x) / (x + (-1.0d0)))) <= 2d-8) then
        tmp = ((-3.0d0) + ((-1.0d0) / x)) / x
    else
        tmp = (((x * (x + (-1.0d0))) - ((x + 1.0d0) * (x + 1.0d0))) / (x * (x + 1.0d0))) / (((x + 1.0d0) / x) * ((x + (-1.0d0)) / (x + 1.0d0)))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (((x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0))) <= 2e-8) {
		tmp = (-3.0 + (-1.0 / x)) / x;
	} else {
		tmp = (((x * (x + -1.0)) - ((x + 1.0) * (x + 1.0))) / (x * (x + 1.0))) / (((x + 1.0) / x) * ((x + -1.0) / (x + 1.0)));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if ((x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0))) <= 2e-8:
		tmp = (-3.0 + (-1.0 / x)) / x
	else:
		tmp = (((x * (x + -1.0)) - ((x + 1.0) * (x + 1.0))) / (x * (x + 1.0))) / (((x + 1.0) / x) * ((x + -1.0) / (x + 1.0)))
	return tmp
function code(x)
	tmp = 0.0
	if (Float64(Float64(x / Float64(x + 1.0)) + Float64(Float64(-1.0 - x) / Float64(x + -1.0))) <= 2e-8)
		tmp = Float64(Float64(-3.0 + Float64(-1.0 / x)) / x);
	else
		tmp = Float64(Float64(Float64(Float64(x * Float64(x + -1.0)) - Float64(Float64(x + 1.0) * Float64(x + 1.0))) / Float64(x * Float64(x + 1.0))) / Float64(Float64(Float64(x + 1.0) / x) * Float64(Float64(x + -1.0) / Float64(x + 1.0))));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (((x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0))) <= 2e-8)
		tmp = (-3.0 + (-1.0 / x)) / x;
	else
		tmp = (((x * (x + -1.0)) - ((x + 1.0) * (x + 1.0))) / (x * (x + 1.0))) / (((x + 1.0) / x) * ((x + -1.0) / (x + 1.0)));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[N[(N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] + N[(N[(-1.0 - x), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 2e-8], N[(N[(-3.0 + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision], N[(N[(N[(N[(x * N[(x + -1.0), $MachinePrecision]), $MachinePrecision] - N[(N[(x + 1.0), $MachinePrecision] * N[(x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(x * N[(x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(x + 1.0), $MachinePrecision] / x), $MachinePrecision] * N[(N[(x + -1.0), $MachinePrecision] / N[(x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{x}{x + 1} + \frac{-1 - x}{x + -1} \leq 2 \cdot 10^{-8}:\\
\;\;\;\;\frac{-3 + \frac{-1}{x}}{x}\\

\mathbf{else}:\\
\;\;\;\;\frac{\frac{x \cdot \left(x + -1\right) - \left(x + 1\right) \cdot \left(x + 1\right)}{x \cdot \left(x + 1\right)}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (/.f64 x (+.f64 x 1)) (/.f64 (+.f64 x 1) (-.f64 x 1))) < 2e-8

    1. Initial program 8.5%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. clear-num8.5%

        \[\leadsto \color{blue}{\frac{1}{\frac{x + 1}{x}}} - \frac{x + 1}{x - 1} \]
      2. clear-num8.5%

        \[\leadsto \frac{1}{\frac{x + 1}{x}} - \color{blue}{\frac{1}{\frac{x - 1}{x + 1}}} \]
      3. frac-sub8.5%

        \[\leadsto \color{blue}{\frac{1 \cdot \frac{x - 1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}}} \]
      4. *-un-lft-identity8.5%

        \[\leadsto \frac{\color{blue}{\frac{x - 1}{x + 1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      5. sub-neg8.5%

        \[\leadsto \frac{\frac{\color{blue}{x + \left(-1\right)}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      6. metadata-eval8.5%

        \[\leadsto \frac{\frac{x + \color{blue}{-1}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      7. sub-neg8.5%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{\color{blue}{x + \left(-1\right)}}{x + 1}} \]
      8. metadata-eval8.5%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + \color{blue}{-1}}{x + 1}} \]
    3. Applied egg-rr8.5%

      \[\leadsto \color{blue}{\frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}} \]
    4. Step-by-step derivation
      1. clear-num8.6%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. metadata-eval8.6%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{x + \color{blue}{\left(-1\right)}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      3. sub-neg8.6%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{x - 1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      4. inv-pow8.6%

        \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x - 1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      5. sub-neg8.6%

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

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

      \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    6. Step-by-step derivation
      1. unpow-18.6%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. +-commutative8.6%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    7. Simplified8.6%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    8. Taylor expanded in x around inf 98.0%

      \[\leadsto \color{blue}{-\left(\frac{1}{{x}^{2}} + 3 \cdot \frac{1}{x}\right)} \]
    9. Step-by-step derivation
      1. neg-sub098.0%

        \[\leadsto \color{blue}{0 - \left(\frac{1}{{x}^{2}} + 3 \cdot \frac{1}{x}\right)} \]
      2. +-commutative98.0%

        \[\leadsto 0 - \color{blue}{\left(3 \cdot \frac{1}{x} + \frac{1}{{x}^{2}}\right)} \]
      3. associate--r+98.0%

        \[\leadsto \color{blue}{\left(0 - 3 \cdot \frac{1}{x}\right) - \frac{1}{{x}^{2}}} \]
      4. neg-sub098.0%

        \[\leadsto \color{blue}{\left(-3 \cdot \frac{1}{x}\right)} - \frac{1}{{x}^{2}} \]
      5. associate-*r/98.5%

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

        \[\leadsto \left(-\frac{\color{blue}{3}}{x}\right) - \frac{1}{{x}^{2}} \]
      7. distribute-neg-frac98.5%

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

        \[\leadsto \frac{\color{blue}{-3}}{x} - \frac{1}{{x}^{2}} \]
      9. unpow298.5%

        \[\leadsto \frac{-3}{x} - \frac{1}{\color{blue}{x \cdot x}} \]
      10. associate-/r*98.5%

        \[\leadsto \frac{-3}{x} - \color{blue}{\frac{\frac{1}{x}}{x}} \]
      11. div-sub98.5%

        \[\leadsto \color{blue}{\frac{-3 - \frac{1}{x}}{x}} \]
    10. Simplified98.5%

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

    if 2e-8 < (-.f64 (/.f64 x (+.f64 x 1)) (/.f64 (+.f64 x 1) (-.f64 x 1)))

    1. Initial program 99.8%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. clear-num99.8%

        \[\leadsto \color{blue}{\frac{1}{\frac{x + 1}{x}}} - \frac{x + 1}{x - 1} \]
      2. clear-num99.8%

        \[\leadsto \frac{1}{\frac{x + 1}{x}} - \color{blue}{\frac{1}{\frac{x - 1}{x + 1}}} \]
      3. frac-sub99.8%

        \[\leadsto \color{blue}{\frac{1 \cdot \frac{x - 1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}}} \]
      4. *-un-lft-identity99.8%

        \[\leadsto \frac{\color{blue}{\frac{x - 1}{x + 1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      5. sub-neg99.8%

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

        \[\leadsto \frac{\frac{x + \color{blue}{-1}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      7. sub-neg99.8%

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

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + \color{blue}{-1}}{x + 1}} \]
    3. Applied egg-rr99.8%

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

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

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{x + \color{blue}{\left(-1\right)}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      3. sub-neg99.8%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{x - 1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      4. inv-pow99.8%

        \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x - 1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      5. sub-neg99.8%

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

        \[\leadsto \frac{{\left(\frac{x + 1}{x + \color{blue}{-1}}\right)}^{-1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    5. Applied egg-rr99.8%

      \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    6. Step-by-step derivation
      1. unpow-199.8%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. +-commutative99.8%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    7. Simplified99.8%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    8. Step-by-step derivation
      1. +-commutative99.8%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. clear-num99.8%

        \[\leadsto \frac{\color{blue}{\frac{x + -1}{x + 1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      3. associate-*l/99.8%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \color{blue}{\frac{\left(x + 1\right) \cdot 1}{x}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      4. frac-sub99.9%

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

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

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

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

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{x + 1} + \frac{-1 - x}{x + -1} \leq 2 \cdot 10^{-8}:\\ \;\;\;\;\frac{-3 + \frac{-1}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{x \cdot \left(x + -1\right) - \left(x + 1\right) \cdot \left(x + 1\right)}{x \cdot \left(x + 1\right)}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}\\ \end{array} \]

Alternative 6: 99.6% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + 1}\\ \mathbf{if}\;t_0 + \frac{-1 - x}{x + -1} \leq 2 \cdot 10^{-8}:\\ \;\;\;\;\frac{-3 + \frac{-1}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{t_0 \cdot \left(x + -1\right) + \left(-1 - x\right)}{x}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (/ x (+ x 1.0))))
   (if (<= (+ t_0 (/ (- -1.0 x) (+ x -1.0))) 2e-8)
     (/ (+ -3.0 (/ -1.0 x)) x)
     (/
      (/ (+ (* t_0 (+ x -1.0)) (- -1.0 x)) x)
      (* (/ (+ x 1.0) x) (/ (+ x -1.0) (+ x 1.0)))))))
double code(double x) {
	double t_0 = x / (x + 1.0);
	double tmp;
	if ((t_0 + ((-1.0 - x) / (x + -1.0))) <= 2e-8) {
		tmp = (-3.0 + (-1.0 / x)) / x;
	} else {
		tmp = (((t_0 * (x + -1.0)) + (-1.0 - x)) / x) / (((x + 1.0) / x) * ((x + -1.0) / (x + 1.0)));
	}
	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)
    if ((t_0 + (((-1.0d0) - x) / (x + (-1.0d0)))) <= 2d-8) then
        tmp = ((-3.0d0) + ((-1.0d0) / x)) / x
    else
        tmp = (((t_0 * (x + (-1.0d0))) + ((-1.0d0) - x)) / x) / (((x + 1.0d0) / x) * ((x + (-1.0d0)) / (x + 1.0d0)))
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = x / (x + 1.0);
	double tmp;
	if ((t_0 + ((-1.0 - x) / (x + -1.0))) <= 2e-8) {
		tmp = (-3.0 + (-1.0 / x)) / x;
	} else {
		tmp = (((t_0 * (x + -1.0)) + (-1.0 - x)) / x) / (((x + 1.0) / x) * ((x + -1.0) / (x + 1.0)));
	}
	return tmp;
}
def code(x):
	t_0 = x / (x + 1.0)
	tmp = 0
	if (t_0 + ((-1.0 - x) / (x + -1.0))) <= 2e-8:
		tmp = (-3.0 + (-1.0 / x)) / x
	else:
		tmp = (((t_0 * (x + -1.0)) + (-1.0 - x)) / x) / (((x + 1.0) / x) * ((x + -1.0) / (x + 1.0)))
	return tmp
function code(x)
	t_0 = Float64(x / Float64(x + 1.0))
	tmp = 0.0
	if (Float64(t_0 + Float64(Float64(-1.0 - x) / Float64(x + -1.0))) <= 2e-8)
		tmp = Float64(Float64(-3.0 + Float64(-1.0 / x)) / x);
	else
		tmp = Float64(Float64(Float64(Float64(t_0 * Float64(x + -1.0)) + Float64(-1.0 - x)) / x) / Float64(Float64(Float64(x + 1.0) / x) * Float64(Float64(x + -1.0) / Float64(x + 1.0))));
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = x / (x + 1.0);
	tmp = 0.0;
	if ((t_0 + ((-1.0 - x) / (x + -1.0))) <= 2e-8)
		tmp = (-3.0 + (-1.0 / x)) / x;
	else
		tmp = (((t_0 * (x + -1.0)) + (-1.0 - x)) / x) / (((x + 1.0) / x) * ((x + -1.0) / (x + 1.0)));
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(t$95$0 + N[(N[(-1.0 - x), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 2e-8], N[(N[(-3.0 + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision], N[(N[(N[(N[(t$95$0 * N[(x + -1.0), $MachinePrecision]), $MachinePrecision] + N[(-1.0 - x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision] / N[(N[(N[(x + 1.0), $MachinePrecision] / x), $MachinePrecision] * N[(N[(x + -1.0), $MachinePrecision] / N[(x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x}{x + 1}\\
\mathbf{if}\;t_0 + \frac{-1 - x}{x + -1} \leq 2 \cdot 10^{-8}:\\
\;\;\;\;\frac{-3 + \frac{-1}{x}}{x}\\

\mathbf{else}:\\
\;\;\;\;\frac{\frac{t_0 \cdot \left(x + -1\right) + \left(-1 - x\right)}{x}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (/.f64 x (+.f64 x 1)) (/.f64 (+.f64 x 1) (-.f64 x 1))) < 2e-8

    1. Initial program 8.5%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. clear-num8.5%

        \[\leadsto \color{blue}{\frac{1}{\frac{x + 1}{x}}} - \frac{x + 1}{x - 1} \]
      2. clear-num8.5%

        \[\leadsto \frac{1}{\frac{x + 1}{x}} - \color{blue}{\frac{1}{\frac{x - 1}{x + 1}}} \]
      3. frac-sub8.5%

        \[\leadsto \color{blue}{\frac{1 \cdot \frac{x - 1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}}} \]
      4. *-un-lft-identity8.5%

        \[\leadsto \frac{\color{blue}{\frac{x - 1}{x + 1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      5. sub-neg8.5%

        \[\leadsto \frac{\frac{\color{blue}{x + \left(-1\right)}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      6. metadata-eval8.5%

        \[\leadsto \frac{\frac{x + \color{blue}{-1}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      7. sub-neg8.5%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{\color{blue}{x + \left(-1\right)}}{x + 1}} \]
      8. metadata-eval8.5%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + \color{blue}{-1}}{x + 1}} \]
    3. Applied egg-rr8.5%

      \[\leadsto \color{blue}{\frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}} \]
    4. Step-by-step derivation
      1. clear-num8.6%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. metadata-eval8.6%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{x + \color{blue}{\left(-1\right)}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      3. sub-neg8.6%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{x - 1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      4. inv-pow8.6%

        \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x - 1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      5. sub-neg8.6%

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

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

      \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    6. Step-by-step derivation
      1. unpow-18.6%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. +-commutative8.6%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    7. Simplified8.6%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    8. Taylor expanded in x around inf 98.0%

      \[\leadsto \color{blue}{-\left(\frac{1}{{x}^{2}} + 3 \cdot \frac{1}{x}\right)} \]
    9. Step-by-step derivation
      1. neg-sub098.0%

        \[\leadsto \color{blue}{0 - \left(\frac{1}{{x}^{2}} + 3 \cdot \frac{1}{x}\right)} \]
      2. +-commutative98.0%

        \[\leadsto 0 - \color{blue}{\left(3 \cdot \frac{1}{x} + \frac{1}{{x}^{2}}\right)} \]
      3. associate--r+98.0%

        \[\leadsto \color{blue}{\left(0 - 3 \cdot \frac{1}{x}\right) - \frac{1}{{x}^{2}}} \]
      4. neg-sub098.0%

        \[\leadsto \color{blue}{\left(-3 \cdot \frac{1}{x}\right)} - \frac{1}{{x}^{2}} \]
      5. associate-*r/98.5%

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

        \[\leadsto \left(-\frac{\color{blue}{3}}{x}\right) - \frac{1}{{x}^{2}} \]
      7. distribute-neg-frac98.5%

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

        \[\leadsto \frac{\color{blue}{-3}}{x} - \frac{1}{{x}^{2}} \]
      9. unpow298.5%

        \[\leadsto \frac{-3}{x} - \frac{1}{\color{blue}{x \cdot x}} \]
      10. associate-/r*98.5%

        \[\leadsto \frac{-3}{x} - \color{blue}{\frac{\frac{1}{x}}{x}} \]
      11. div-sub98.5%

        \[\leadsto \color{blue}{\frac{-3 - \frac{1}{x}}{x}} \]
    10. Simplified98.5%

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

    if 2e-8 < (-.f64 (/.f64 x (+.f64 x 1)) (/.f64 (+.f64 x 1) (-.f64 x 1)))

    1. Initial program 99.8%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. clear-num99.8%

        \[\leadsto \color{blue}{\frac{1}{\frac{x + 1}{x}}} - \frac{x + 1}{x - 1} \]
      2. clear-num99.8%

        \[\leadsto \frac{1}{\frac{x + 1}{x}} - \color{blue}{\frac{1}{\frac{x - 1}{x + 1}}} \]
      3. frac-sub99.8%

        \[\leadsto \color{blue}{\frac{1 \cdot \frac{x - 1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}}} \]
      4. *-un-lft-identity99.8%

        \[\leadsto \frac{\color{blue}{\frac{x - 1}{x + 1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      5. sub-neg99.8%

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

        \[\leadsto \frac{\frac{x + \color{blue}{-1}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      7. sub-neg99.8%

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

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + \color{blue}{-1}}{x + 1}} \]
    3. Applied egg-rr99.8%

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

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

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{x + \color{blue}{\left(-1\right)}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      3. sub-neg99.8%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{x - 1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      4. inv-pow99.8%

        \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x - 1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      5. sub-neg99.8%

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

        \[\leadsto \frac{{\left(\frac{x + 1}{x + \color{blue}{-1}}\right)}^{-1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    5. Applied egg-rr99.8%

      \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    6. Step-by-step derivation
      1. unpow-199.8%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. +-commutative99.8%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    7. Simplified99.8%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    8. Step-by-step derivation
      1. +-commutative99.8%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. clear-num99.8%

        \[\leadsto \frac{\color{blue}{\frac{x + -1}{x + 1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      3. *-rgt-identity99.8%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \color{blue}{\frac{x + 1}{x}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      4. clear-num99.8%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \color{blue}{\frac{1}{\frac{x}{x + 1}}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      5. frac-sub99.9%

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

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

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

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

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

      \[\leadsto \frac{\color{blue}{\frac{\left(x + -1\right) \cdot \frac{x}{1 + x} - \left(1 + x\right) \cdot 1}{\left(1 + x\right) \cdot \frac{x}{1 + x}}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    10. Step-by-step derivation
      1. +-commutative99.9%

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

        \[\leadsto \frac{\frac{\left(-1 + x\right) \cdot \frac{x}{\color{blue}{x + 1}} - \left(1 + x\right) \cdot 1}{\left(1 + x\right) \cdot \frac{x}{1 + x}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      3. *-rgt-identity99.9%

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

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

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

        \[\leadsto \frac{\frac{\left(-1 + x\right) \cdot \frac{x}{x + 1} - \left(x + 1\right)}{\left(x + 1\right) \cdot \frac{x}{\color{blue}{x + 1}}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    11. Simplified99.9%

      \[\leadsto \frac{\color{blue}{\frac{\left(-1 + x\right) \cdot \frac{x}{x + 1} - \left(x + 1\right)}{\left(x + 1\right) \cdot \frac{x}{x + 1}}}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    12. Taylor expanded in x around 0 99.9%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{x + 1} + \frac{-1 - x}{x + -1} \leq 2 \cdot 10^{-8}:\\ \;\;\;\;\frac{-3 + \frac{-1}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\frac{x}{x + 1} \cdot \left(x + -1\right) + \left(-1 - x\right)}{x}}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}\\ \end{array} \]

Alternative 7: 99.6% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + 1} + \frac{-1 - x}{x + -1}\\ \mathbf{if}\;t_0 \leq 2 \cdot 10^{-8}:\\ \;\;\;\;\frac{-3 + \frac{-1}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;t_0\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (+ (/ x (+ x 1.0)) (/ (- -1.0 x) (+ x -1.0)))))
   (if (<= t_0 2e-8) (/ (+ -3.0 (/ -1.0 x)) x) t_0)))
double code(double x) {
	double t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0));
	double tmp;
	if (t_0 <= 2e-8) {
		tmp = (-3.0 + (-1.0 / 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)) + (((-1.0d0) - x) / (x + (-1.0d0)))
    if (t_0 <= 2d-8) then
        tmp = ((-3.0d0) + ((-1.0d0) / 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)) + ((-1.0 - x) / (x + -1.0));
	double tmp;
	if (t_0 <= 2e-8) {
		tmp = (-3.0 + (-1.0 / x)) / x;
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x):
	t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0))
	tmp = 0
	if t_0 <= 2e-8:
		tmp = (-3.0 + (-1.0 / x)) / x
	else:
		tmp = t_0
	return tmp
function code(x)
	t_0 = Float64(Float64(x / Float64(x + 1.0)) + Float64(Float64(-1.0 - x) / Float64(x + -1.0)))
	tmp = 0.0
	if (t_0 <= 2e-8)
		tmp = Float64(Float64(-3.0 + Float64(-1.0 / x)) / x);
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0));
	tmp = 0.0;
	if (t_0 <= 2e-8)
		tmp = (-3.0 + (-1.0 / 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[(-1.0 - x), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 2e-8], N[(N[(-3.0 + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision], t$95$0]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x}{x + 1} + \frac{-1 - x}{x + -1}\\
\mathbf{if}\;t_0 \leq 2 \cdot 10^{-8}:\\
\;\;\;\;\frac{-3 + \frac{-1}{x}}{x}\\

\mathbf{else}:\\
\;\;\;\;t_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (/.f64 x (+.f64 x 1)) (/.f64 (+.f64 x 1) (-.f64 x 1))) < 2e-8

    1. Initial program 8.5%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. clear-num8.5%

        \[\leadsto \color{blue}{\frac{1}{\frac{x + 1}{x}}} - \frac{x + 1}{x - 1} \]
      2. clear-num8.5%

        \[\leadsto \frac{1}{\frac{x + 1}{x}} - \color{blue}{\frac{1}{\frac{x - 1}{x + 1}}} \]
      3. frac-sub8.5%

        \[\leadsto \color{blue}{\frac{1 \cdot \frac{x - 1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}}} \]
      4. *-un-lft-identity8.5%

        \[\leadsto \frac{\color{blue}{\frac{x - 1}{x + 1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      5. sub-neg8.5%

        \[\leadsto \frac{\frac{\color{blue}{x + \left(-1\right)}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      6. metadata-eval8.5%

        \[\leadsto \frac{\frac{x + \color{blue}{-1}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      7. sub-neg8.5%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{\color{blue}{x + \left(-1\right)}}{x + 1}} \]
      8. metadata-eval8.5%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + \color{blue}{-1}}{x + 1}} \]
    3. Applied egg-rr8.5%

      \[\leadsto \color{blue}{\frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}} \]
    4. Step-by-step derivation
      1. clear-num8.6%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. metadata-eval8.6%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{x + \color{blue}{\left(-1\right)}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      3. sub-neg8.6%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{x - 1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      4. inv-pow8.6%

        \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x - 1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      5. sub-neg8.6%

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

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

      \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    6. Step-by-step derivation
      1. unpow-18.6%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. +-commutative8.6%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    7. Simplified8.6%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    8. Taylor expanded in x around inf 98.0%

      \[\leadsto \color{blue}{-\left(\frac{1}{{x}^{2}} + 3 \cdot \frac{1}{x}\right)} \]
    9. Step-by-step derivation
      1. neg-sub098.0%

        \[\leadsto \color{blue}{0 - \left(\frac{1}{{x}^{2}} + 3 \cdot \frac{1}{x}\right)} \]
      2. +-commutative98.0%

        \[\leadsto 0 - \color{blue}{\left(3 \cdot \frac{1}{x} + \frac{1}{{x}^{2}}\right)} \]
      3. associate--r+98.0%

        \[\leadsto \color{blue}{\left(0 - 3 \cdot \frac{1}{x}\right) - \frac{1}{{x}^{2}}} \]
      4. neg-sub098.0%

        \[\leadsto \color{blue}{\left(-3 \cdot \frac{1}{x}\right)} - \frac{1}{{x}^{2}} \]
      5. associate-*r/98.5%

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

        \[\leadsto \left(-\frac{\color{blue}{3}}{x}\right) - \frac{1}{{x}^{2}} \]
      7. distribute-neg-frac98.5%

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

        \[\leadsto \frac{\color{blue}{-3}}{x} - \frac{1}{{x}^{2}} \]
      9. unpow298.5%

        \[\leadsto \frac{-3}{x} - \frac{1}{\color{blue}{x \cdot x}} \]
      10. associate-/r*98.5%

        \[\leadsto \frac{-3}{x} - \color{blue}{\frac{\frac{1}{x}}{x}} \]
      11. div-sub98.5%

        \[\leadsto \color{blue}{\frac{-3 - \frac{1}{x}}{x}} \]
    10. Simplified98.5%

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

    if 2e-8 < (-.f64 (/.f64 x (+.f64 x 1)) (/.f64 (+.f64 x 1) (-.f64 x 1)))

    1. Initial program 99.8%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{x + 1} + \frac{-1 - x}{x + -1} \leq 2 \cdot 10^{-8}:\\ \;\;\;\;\frac{-3 + \frac{-1}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{x + 1} + \frac{-1 - x}{x + -1}\\ \end{array} \]

Alternative 8: 99.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1.7\right):\\ \;\;\;\;\frac{-3 + \frac{-1}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;x + \frac{-1 - x}{x + -1}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (or (<= x -1.0) (not (<= x 1.7)))
   (/ (+ -3.0 (/ -1.0 x)) x)
   (+ x (/ (- -1.0 x) (+ x -1.0)))))
double code(double x) {
	double tmp;
	if ((x <= -1.0) || !(x <= 1.7)) {
		tmp = (-3.0 + (-1.0 / x)) / x;
	} else {
		tmp = x + ((-1.0 - x) / (x + -1.0));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if ((x <= (-1.0d0)) .or. (.not. (x <= 1.7d0))) then
        tmp = ((-3.0d0) + ((-1.0d0) / x)) / x
    else
        tmp = x + (((-1.0d0) - x) / (x + (-1.0d0)))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if ((x <= -1.0) || !(x <= 1.7)) {
		tmp = (-3.0 + (-1.0 / x)) / x;
	} else {
		tmp = x + ((-1.0 - x) / (x + -1.0));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if (x <= -1.0) or not (x <= 1.7):
		tmp = (-3.0 + (-1.0 / x)) / x
	else:
		tmp = x + ((-1.0 - x) / (x + -1.0))
	return tmp
function code(x)
	tmp = 0.0
	if ((x <= -1.0) || !(x <= 1.7))
		tmp = Float64(Float64(-3.0 + Float64(-1.0 / x)) / x);
	else
		tmp = Float64(x + Float64(Float64(-1.0 - x) / Float64(x + -1.0)));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if ((x <= -1.0) || ~((x <= 1.7)))
		tmp = (-3.0 + (-1.0 / x)) / x;
	else
		tmp = x + ((-1.0 - x) / (x + -1.0));
	end
	tmp_2 = tmp;
end
code[x_] := If[Or[LessEqual[x, -1.0], N[Not[LessEqual[x, 1.7]], $MachinePrecision]], N[(N[(-3.0 + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision], N[(x + N[(N[(-1.0 - x), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1.7\right):\\
\;\;\;\;\frac{-3 + \frac{-1}{x}}{x}\\

\mathbf{else}:\\
\;\;\;\;x + \frac{-1 - x}{x + -1}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1 or 1.69999999999999996 < x

    1. Initial program 9.1%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. clear-num9.1%

        \[\leadsto \color{blue}{\frac{1}{\frac{x + 1}{x}}} - \frac{x + 1}{x - 1} \]
      2. clear-num9.1%

        \[\leadsto \frac{1}{\frac{x + 1}{x}} - \color{blue}{\frac{1}{\frac{x - 1}{x + 1}}} \]
      3. frac-sub9.1%

        \[\leadsto \color{blue}{\frac{1 \cdot \frac{x - 1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}}} \]
      4. *-un-lft-identity9.1%

        \[\leadsto \frac{\color{blue}{\frac{x - 1}{x + 1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      5. sub-neg9.1%

        \[\leadsto \frac{\frac{\color{blue}{x + \left(-1\right)}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      6. metadata-eval9.1%

        \[\leadsto \frac{\frac{x + \color{blue}{-1}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      7. sub-neg9.1%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{\color{blue}{x + \left(-1\right)}}{x + 1}} \]
      8. metadata-eval9.1%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + \color{blue}{-1}}{x + 1}} \]
    3. Applied egg-rr9.1%

      \[\leadsto \color{blue}{\frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}} \]
    4. Step-by-step derivation
      1. clear-num9.1%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. metadata-eval9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{x + \color{blue}{\left(-1\right)}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      3. sub-neg9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{x - 1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      4. inv-pow9.1%

        \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x - 1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      5. sub-neg9.1%

        \[\leadsto \frac{{\left(\frac{x + 1}{\color{blue}{x + \left(-1\right)}}\right)}^{-1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      6. metadata-eval9.1%

        \[\leadsto \frac{{\left(\frac{x + 1}{x + \color{blue}{-1}}\right)}^{-1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    5. Applied egg-rr9.1%

      \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    6. Step-by-step derivation
      1. unpow-19.1%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. +-commutative9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    7. Simplified9.1%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    8. Taylor expanded in x around inf 97.7%

      \[\leadsto \color{blue}{-\left(\frac{1}{{x}^{2}} + 3 \cdot \frac{1}{x}\right)} \]
    9. Step-by-step derivation
      1. neg-sub097.7%

        \[\leadsto \color{blue}{0 - \left(\frac{1}{{x}^{2}} + 3 \cdot \frac{1}{x}\right)} \]
      2. +-commutative97.7%

        \[\leadsto 0 - \color{blue}{\left(3 \cdot \frac{1}{x} + \frac{1}{{x}^{2}}\right)} \]
      3. associate--r+97.7%

        \[\leadsto \color{blue}{\left(0 - 3 \cdot \frac{1}{x}\right) - \frac{1}{{x}^{2}}} \]
      4. neg-sub097.7%

        \[\leadsto \color{blue}{\left(-3 \cdot \frac{1}{x}\right)} - \frac{1}{{x}^{2}} \]
      5. associate-*r/98.3%

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

        \[\leadsto \left(-\frac{\color{blue}{3}}{x}\right) - \frac{1}{{x}^{2}} \]
      7. distribute-neg-frac98.3%

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

        \[\leadsto \frac{\color{blue}{-3}}{x} - \frac{1}{{x}^{2}} \]
      9. unpow298.3%

        \[\leadsto \frac{-3}{x} - \frac{1}{\color{blue}{x \cdot x}} \]
      10. associate-/r*98.3%

        \[\leadsto \frac{-3}{x} - \color{blue}{\frac{\frac{1}{x}}{x}} \]
      11. div-sub98.3%

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

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

    if -1 < x < 1.69999999999999996

    1. Initial program 100.0%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Taylor expanded in x around 0 98.3%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1.7\right):\\ \;\;\;\;\frac{-3 + \frac{-1}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;x + \frac{-1 - x}{x + -1}\\ \end{array} \]

Alternative 9: 99.1% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\ \;\;\;\;\frac{-3 + \frac{-1}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;1 + x \cdot 3\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (or (<= x -1.0) (not (<= x 1.0)))
   (/ (+ -3.0 (/ -1.0 x)) x)
   (+ 1.0 (* x 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 * 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 * 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 * 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 * 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 * 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 * 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 * 3.0), $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 3\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1 or 1 < x

    1. Initial program 9.1%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. clear-num9.1%

        \[\leadsto \color{blue}{\frac{1}{\frac{x + 1}{x}}} - \frac{x + 1}{x - 1} \]
      2. clear-num9.1%

        \[\leadsto \frac{1}{\frac{x + 1}{x}} - \color{blue}{\frac{1}{\frac{x - 1}{x + 1}}} \]
      3. frac-sub9.1%

        \[\leadsto \color{blue}{\frac{1 \cdot \frac{x - 1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}}} \]
      4. *-un-lft-identity9.1%

        \[\leadsto \frac{\color{blue}{\frac{x - 1}{x + 1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      5. sub-neg9.1%

        \[\leadsto \frac{\frac{\color{blue}{x + \left(-1\right)}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      6. metadata-eval9.1%

        \[\leadsto \frac{\frac{x + \color{blue}{-1}}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x - 1}{x + 1}} \]
      7. sub-neg9.1%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{\color{blue}{x + \left(-1\right)}}{x + 1}} \]
      8. metadata-eval9.1%

        \[\leadsto \frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + \color{blue}{-1}}{x + 1}} \]
    3. Applied egg-rr9.1%

      \[\leadsto \color{blue}{\frac{\frac{x + -1}{x + 1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}}} \]
    4. Step-by-step derivation
      1. clear-num9.1%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. metadata-eval9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{x + \color{blue}{\left(-1\right)}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      3. sub-neg9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{x - 1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      4. inv-pow9.1%

        \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x - 1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      5. sub-neg9.1%

        \[\leadsto \frac{{\left(\frac{x + 1}{\color{blue}{x + \left(-1\right)}}\right)}^{-1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      6. metadata-eval9.1%

        \[\leadsto \frac{{\left(\frac{x + 1}{x + \color{blue}{-1}}\right)}^{-1} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    5. Applied egg-rr9.1%

      \[\leadsto \frac{\color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{-1}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    6. Step-by-step derivation
      1. unpow-19.1%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{x + -1}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
      2. +-commutative9.1%

        \[\leadsto \frac{\frac{1}{\frac{x + 1}{\color{blue}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    7. Simplified9.1%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x + 1}{-1 + x}}} - \frac{x + 1}{x} \cdot 1}{\frac{x + 1}{x} \cdot \frac{x + -1}{x + 1}} \]
    8. Taylor expanded in x around inf 97.7%

      \[\leadsto \color{blue}{-\left(\frac{1}{{x}^{2}} + 3 \cdot \frac{1}{x}\right)} \]
    9. Step-by-step derivation
      1. neg-sub097.7%

        \[\leadsto \color{blue}{0 - \left(\frac{1}{{x}^{2}} + 3 \cdot \frac{1}{x}\right)} \]
      2. +-commutative97.7%

        \[\leadsto 0 - \color{blue}{\left(3 \cdot \frac{1}{x} + \frac{1}{{x}^{2}}\right)} \]
      3. associate--r+97.7%

        \[\leadsto \color{blue}{\left(0 - 3 \cdot \frac{1}{x}\right) - \frac{1}{{x}^{2}}} \]
      4. neg-sub097.7%

        \[\leadsto \color{blue}{\left(-3 \cdot \frac{1}{x}\right)} - \frac{1}{{x}^{2}} \]
      5. associate-*r/98.3%

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

        \[\leadsto \left(-\frac{\color{blue}{3}}{x}\right) - \frac{1}{{x}^{2}} \]
      7. distribute-neg-frac98.3%

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

        \[\leadsto \frac{\color{blue}{-3}}{x} - \frac{1}{{x}^{2}} \]
      9. unpow298.3%

        \[\leadsto \frac{-3}{x} - \frac{1}{\color{blue}{x \cdot x}} \]
      10. associate-/r*98.3%

        \[\leadsto \frac{-3}{x} - \color{blue}{\frac{\frac{1}{x}}{x}} \]
      11. div-sub98.3%

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

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

    if -1 < x < 1

    1. Initial program 100.0%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Taylor expanded in x around 0 98.2%

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

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

Alternative 10: 98.6% accurate, 1.4× speedup?

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

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1:\\
\;\;\;\;\frac{-3}{x}\\

\mathbf{elif}\;x \leq 1:\\
\;\;\;\;1 + x \cdot 3\\

\mathbf{else}:\\
\;\;\;\;\frac{-3}{x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1 or 1 < x

    1. Initial program 9.1%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Taylor expanded in x around inf 97.3%

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

    if -1 < x < 1

    1. Initial program 100.0%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Taylor expanded in x around 0 98.2%

      \[\leadsto \color{blue}{3 \cdot x + 1} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification97.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1:\\ \;\;\;\;\frac{-3}{x}\\ \mathbf{elif}\;x \leq 1:\\ \;\;\;\;1 + x \cdot 3\\ \mathbf{else}:\\ \;\;\;\;\frac{-3}{x}\\ \end{array} \]

Alternative 11: 98.0% accurate, 1.8× speedup?

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

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1:\\
\;\;\;\;\frac{-3}{x}\\

\mathbf{elif}\;x \leq 1:\\
\;\;\;\;x - -1\\

\mathbf{else}:\\
\;\;\;\;\frac{-3}{x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1 or 1 < x

    1. Initial program 9.1%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Taylor expanded in x around inf 97.3%

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

    if -1 < x < 1

    1. Initial program 100.0%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Taylor expanded in x around 0 98.3%

      \[\leadsto \color{blue}{x} - \frac{x + 1}{x - 1} \]
    3. Taylor expanded in x around 0 97.1%

      \[\leadsto x - \color{blue}{-1} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification97.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1:\\ \;\;\;\;\frac{-3}{x}\\ \mathbf{elif}\;x \leq 1:\\ \;\;\;\;x - -1\\ \mathbf{else}:\\ \;\;\;\;\frac{-3}{x}\\ \end{array} \]

Alternative 12: 50.3% 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 57.0%

    \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
  2. Taylor expanded in x around 0 53.0%

    \[\leadsto \color{blue}{1} \]
  3. Final simplification53.0%

    \[\leadsto 1 \]

Reproduce

?
herbie shell --seed 2023175 
(FPCore (x)
  :name "Asymptote C"
  :precision binary64
  (- (/ x (+ x 1.0)) (/ (+ x 1.0) (- x 1.0))))