Asymptote C

Percentage Accurate: 55.3% → 99.2%
Time: 7.6s
Alternatives: 8
Speedup: 1.0×

Specification

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

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

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 8 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: 55.3% 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: 99.2% accurate, 0.4× speedup?

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

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

\mathbf{else}:\\
\;\;\;\;1 + x \cdot \left(x + 3\right)\\


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

    1. Initial program 7.6%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. remove-double-neg7.6%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\left(-\frac{x + 1}{x - 1}\right)\right)} \]
      2. distribute-neg-frac7.6%

        \[\leadsto \frac{x}{x + 1} - \left(-\color{blue}{\frac{-\left(x + 1\right)}{x - 1}}\right) \]
      3. distribute-neg-in7.6%

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

        \[\leadsto \frac{x}{x + 1} - \left(-\frac{\color{blue}{\left(-x\right) - 1}}{x - 1}\right) \]
      5. distribute-frac-neg27.6%

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

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
      7. +-commutative7.6%

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

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
      9. metadata-eval7.6%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
      10. neg-sub07.6%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
      11. associate-+l-7.6%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
      12. neg-sub07.6%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
      13. +-commutative7.6%

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

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
    3. Simplified7.6%

      \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 99.9%

      \[\leadsto \color{blue}{\frac{-1 \cdot \frac{3 + \frac{1}{x}}{{x}^{2}} - \left(3 + \frac{1}{x}\right)}{x}} \]
    6. Step-by-step derivation
      1. Simplified99.9%

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

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

      1. Initial program 100.0%

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

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\left(-\frac{x + 1}{x - 1}\right)\right)} \]
        2. distribute-neg-frac100.0%

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 100.0%

        \[\leadsto \color{blue}{1 + x \cdot \left(3 + x\right)} \]
    7. Recombined 2 regimes into one program.
    8. Final simplification100.0%

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

    Alternative 2: 99.6% accurate, 0.4× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + 1} + \frac{-1 - x}{x + -1}\\ \mathbf{if}\;t\_0 \leq 5 \cdot 10^{-8}:\\ \;\;\;\;\frac{-3 + \frac{-1 + \frac{-3}{x}}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (let* ((t_0 (+ (/ x (+ x 1.0)) (/ (- -1.0 x) (+ x -1.0)))))
       (if (<= t_0 5e-8) (/ (+ -3.0 (/ (+ -1.0 (/ -3.0 x)) 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 <= 5e-8) {
    		tmp = (-3.0 + ((-1.0 + (-3.0 / x)) / x)) / x;
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        real(8) :: t_0
        real(8) :: tmp
        t_0 = (x / (x + 1.0d0)) + (((-1.0d0) - x) / (x + (-1.0d0)))
        if (t_0 <= 5d-8) then
            tmp = ((-3.0d0) + (((-1.0d0) + ((-3.0d0) / x)) / x)) / x
        else
            tmp = t_0
        end if
        code = tmp
    end function
    
    public static double code(double x) {
    	double t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0));
    	double tmp;
    	if (t_0 <= 5e-8) {
    		tmp = (-3.0 + ((-1.0 + (-3.0 / x)) / x)) / x;
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    def code(x):
    	t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0))
    	tmp = 0
    	if t_0 <= 5e-8:
    		tmp = (-3.0 + ((-1.0 + (-3.0 / x)) / x)) / x
    	else:
    		tmp = t_0
    	return tmp
    
    function code(x)
    	t_0 = Float64(Float64(x / Float64(x + 1.0)) + Float64(Float64(-1.0 - x) / Float64(x + -1.0)))
    	tmp = 0.0
    	if (t_0 <= 5e-8)
    		tmp = Float64(Float64(-3.0 + Float64(Float64(-1.0 + Float64(-3.0 / x)) / x)) / x);
    	else
    		tmp = t_0;
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0));
    	tmp = 0.0;
    	if (t_0 <= 5e-8)
    		tmp = (-3.0 + ((-1.0 + (-3.0 / x)) / x)) / x;
    	else
    		tmp = t_0;
    	end
    	tmp_2 = tmp;
    end
    
    code[x_] := Block[{t$95$0 = N[(N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] + N[(N[(-1.0 - x), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 5e-8], N[(N[(-3.0 + N[(N[(-1.0 + N[(-3.0 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision], t$95$0]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := \frac{x}{x + 1} + \frac{-1 - x}{x + -1}\\
    \mathbf{if}\;t\_0 \leq 5 \cdot 10^{-8}:\\
    \;\;\;\;\frac{-3 + \frac{-1 + \frac{-3}{x}}{x}}{x}\\
    
    \mathbf{else}:\\
    \;\;\;\;t\_0\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64)))) < 4.9999999999999998e-8

      1. Initial program 7.0%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg7.0%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\left(-\frac{x + 1}{x - 1}\right)\right)} \]
        2. distribute-neg-frac7.0%

          \[\leadsto \frac{x}{x + 1} - \left(-\color{blue}{\frac{-\left(x + 1\right)}{x - 1}}\right) \]
        3. distribute-neg-in7.0%

          \[\leadsto \frac{x}{x + 1} - \left(-\frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{x - 1}\right) \]
        4. sub-neg7.0%

          \[\leadsto \frac{x}{x + 1} - \left(-\frac{\color{blue}{\left(-x\right) - 1}}{x - 1}\right) \]
        5. distribute-frac-neg27.0%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg7.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative7.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg7.0%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval7.0%

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

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-7.0%

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

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative7.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg7.0%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified7.0%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around inf 100.0%

        \[\leadsto \color{blue}{\frac{-1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x} - 3}{x}} \]
      6. Step-by-step derivation
        1. sub-neg100.0%

          \[\leadsto \frac{\color{blue}{-1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x} + \left(-3\right)}}{x} \]
        2. metadata-eval100.0%

          \[\leadsto \frac{-1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x} + \color{blue}{-3}}{x} \]
        3. +-commutative100.0%

          \[\leadsto \frac{\color{blue}{-3 + -1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x}}}{x} \]
        4. associate-*r/100.0%

          \[\leadsto \frac{-3 + \color{blue}{\frac{-1 \cdot \left(1 + 3 \cdot \frac{1}{x}\right)}{x}}}{x} \]
        5. distribute-lft-in100.0%

          \[\leadsto \frac{-3 + \frac{\color{blue}{-1 \cdot 1 + -1 \cdot \left(3 \cdot \frac{1}{x}\right)}}{x}}{x} \]
        6. metadata-eval100.0%

          \[\leadsto \frac{-3 + \frac{\color{blue}{-1} + -1 \cdot \left(3 \cdot \frac{1}{x}\right)}{x}}{x} \]
        7. neg-mul-1100.0%

          \[\leadsto \frac{-3 + \frac{-1 + \color{blue}{\left(-3 \cdot \frac{1}{x}\right)}}{x}}{x} \]
        8. associate-*r/100.0%

          \[\leadsto \frac{-3 + \frac{-1 + \left(-\color{blue}{\frac{3 \cdot 1}{x}}\right)}{x}}{x} \]
        9. metadata-eval100.0%

          \[\leadsto \frac{-3 + \frac{-1 + \left(-\frac{\color{blue}{3}}{x}\right)}{x}}{x} \]
        10. distribute-neg-frac100.0%

          \[\leadsto \frac{-3 + \frac{-1 + \color{blue}{\frac{-3}{x}}}{x}}{x} \]
        11. metadata-eval100.0%

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

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

      if 4.9999999999999998e-8 < (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64))))

      1. Initial program 99.8%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Add Preprocessing
    3. Recombined 2 regimes into one program.
    4. Final simplification99.9%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{x + 1} + \frac{-1 - x}{x + -1} \leq 5 \cdot 10^{-8}:\\ \;\;\;\;\frac{-3 + \frac{-1 + \frac{-3}{x}}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{x + 1} + \frac{-1 - x}{x + -1}\\ \end{array} \]
    5. Add Preprocessing

    Alternative 3: 98.6% accurate, 0.8× speedup?

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

      1. Initial program 7.6%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg7.6%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\left(-\frac{x + 1}{x - 1}\right)\right)} \]
        2. distribute-neg-frac7.6%

          \[\leadsto \frac{x}{x + 1} - \left(-\color{blue}{\frac{-\left(x + 1\right)}{x - 1}}\right) \]
        3. distribute-neg-in7.6%

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

          \[\leadsto \frac{x}{x + 1} - \left(-\frac{\color{blue}{\left(-x\right) - 1}}{x - 1}\right) \]
        5. distribute-frac-neg27.6%

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

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative7.6%

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

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval7.6%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub07.6%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-7.6%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub07.6%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative7.6%

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

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified7.6%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around inf 99.0%

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

      if -1 < x < 1

      1. Initial program 100.0%

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

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\left(-\frac{x + 1}{x - 1}\right)\right)} \]
        2. distribute-neg-frac100.0%

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 100.0%

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

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

    Alternative 4: 99.1% accurate, 0.8× speedup?

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

      1. Initial program 7.6%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg7.6%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\left(-\frac{x + 1}{x - 1}\right)\right)} \]
        2. distribute-neg-frac7.6%

          \[\leadsto \frac{x}{x + 1} - \left(-\color{blue}{\frac{-\left(x + 1\right)}{x - 1}}\right) \]
        3. distribute-neg-in7.6%

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

          \[\leadsto \frac{x}{x + 1} - \left(-\frac{\color{blue}{\left(-x\right) - 1}}{x - 1}\right) \]
        5. distribute-frac-neg27.6%

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

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative7.6%

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

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval7.6%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub07.6%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-7.6%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub07.6%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative7.6%

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

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified7.6%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around inf 99.7%

        \[\leadsto \color{blue}{-1 \cdot \frac{3 + \frac{1}{x}}{x}} \]
      6. Step-by-step derivation
        1. associate-*r/99.7%

          \[\leadsto \color{blue}{\frac{-1 \cdot \left(3 + \frac{1}{x}\right)}{x}} \]
        2. neg-mul-199.7%

          \[\leadsto \frac{\color{blue}{-\left(3 + \frac{1}{x}\right)}}{x} \]
        3. distribute-neg-in99.7%

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

          \[\leadsto \frac{\color{blue}{-3} + \left(-\frac{1}{x}\right)}{x} \]
        5. distribute-neg-frac99.7%

          \[\leadsto \frac{-3 + \color{blue}{\frac{-1}{x}}}{x} \]
        6. metadata-eval99.7%

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

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

      if -1 < x < 1

      1. Initial program 100.0%

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

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\left(-\frac{x + 1}{x - 1}\right)\right)} \]
        2. distribute-neg-frac100.0%

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 100.0%

        \[\leadsto \color{blue}{1 + x \cdot \left(3 + x\right)} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification99.8%

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

    Alternative 5: 99.2% accurate, 0.8× speedup?

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

      1. Initial program 9.4%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg9.4%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\left(-\frac{x + 1}{x - 1}\right)\right)} \]
        2. distribute-neg-frac9.4%

          \[\leadsto \frac{x}{x + 1} - \left(-\color{blue}{\frac{-\left(x + 1\right)}{x - 1}}\right) \]
        3. distribute-neg-in9.4%

          \[\leadsto \frac{x}{x + 1} - \left(-\frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{x - 1}\right) \]
        4. sub-neg9.4%

          \[\leadsto \frac{x}{x + 1} - \left(-\frac{\color{blue}{\left(-x\right) - 1}}{x - 1}\right) \]
        5. distribute-frac-neg29.4%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg9.4%

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

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg9.4%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval9.4%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub09.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-9.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub09.4%

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

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg9.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified9.4%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around inf 99.7%

        \[\leadsto \color{blue}{\frac{-1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x} - 3}{x}} \]
      6. Step-by-step derivation
        1. sub-neg99.7%

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

          \[\leadsto \frac{-1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x} + \color{blue}{-3}}{x} \]
        3. +-commutative99.7%

          \[\leadsto \frac{\color{blue}{-3 + -1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x}}}{x} \]
        4. associate-*r/99.7%

          \[\leadsto \frac{-3 + \color{blue}{\frac{-1 \cdot \left(1 + 3 \cdot \frac{1}{x}\right)}{x}}}{x} \]
        5. distribute-lft-in99.7%

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

          \[\leadsto \frac{-3 + \frac{\color{blue}{-1} + -1 \cdot \left(3 \cdot \frac{1}{x}\right)}{x}}{x} \]
        7. neg-mul-199.7%

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

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

          \[\leadsto \frac{-3 + \frac{-1 + \left(-\frac{\color{blue}{3}}{x}\right)}{x}}{x} \]
        10. distribute-neg-frac99.7%

          \[\leadsto \frac{-3 + \frac{-1 + \color{blue}{\frac{-3}{x}}}{x}}{x} \]
        11. metadata-eval99.7%

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

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

      if -1 < x < 1

      1. Initial program 100.0%

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

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\left(-\frac{x + 1}{x - 1}\right)\right)} \]
        2. distribute-neg-frac100.0%

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 100.0%

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

      if 1 < x

      1. Initial program 5.8%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg5.8%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\left(-\frac{x + 1}{x - 1}\right)\right)} \]
        2. distribute-neg-frac5.8%

          \[\leadsto \frac{x}{x + 1} - \left(-\color{blue}{\frac{-\left(x + 1\right)}{x - 1}}\right) \]
        3. distribute-neg-in5.8%

          \[\leadsto \frac{x}{x + 1} - \left(-\frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{x - 1}\right) \]
        4. sub-neg5.8%

          \[\leadsto \frac{x}{x + 1} - \left(-\frac{\color{blue}{\left(-x\right) - 1}}{x - 1}\right) \]
        5. distribute-frac-neg25.8%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg5.8%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative5.8%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg5.8%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval5.8%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub05.8%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-5.8%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub05.8%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative5.8%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg5.8%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified5.8%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around inf 100.0%

        \[\leadsto \color{blue}{-1 \cdot \frac{3 + \frac{1}{x}}{x}} \]
      6. Step-by-step derivation
        1. associate-*r/100.0%

          \[\leadsto \color{blue}{\frac{-1 \cdot \left(3 + \frac{1}{x}\right)}{x}} \]
        2. neg-mul-1100.0%

          \[\leadsto \frac{\color{blue}{-\left(3 + \frac{1}{x}\right)}}{x} \]
        3. distribute-neg-in100.0%

          \[\leadsto \frac{\color{blue}{\left(-3\right) + \left(-\frac{1}{x}\right)}}{x} \]
        4. metadata-eval100.0%

          \[\leadsto \frac{\color{blue}{-3} + \left(-\frac{1}{x}\right)}{x} \]
        5. distribute-neg-frac100.0%

          \[\leadsto \frac{-3 + \color{blue}{\frac{-1}{x}}}{x} \]
        6. metadata-eval100.0%

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

        \[\leadsto \color{blue}{\frac{-3 + \frac{-1}{x}}{x}} \]
    3. Recombined 3 regimes into one program.
    4. Final simplification99.9%

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

    Alternative 6: 98.5% accurate, 0.9× speedup?

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

      1. Initial program 7.6%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg7.6%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\left(-\frac{x + 1}{x - 1}\right)\right)} \]
        2. distribute-neg-frac7.6%

          \[\leadsto \frac{x}{x + 1} - \left(-\color{blue}{\frac{-\left(x + 1\right)}{x - 1}}\right) \]
        3. distribute-neg-in7.6%

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

          \[\leadsto \frac{x}{x + 1} - \left(-\frac{\color{blue}{\left(-x\right) - 1}}{x - 1}\right) \]
        5. distribute-frac-neg27.6%

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

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative7.6%

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

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval7.6%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub07.6%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-7.6%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub07.6%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative7.6%

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

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified7.6%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around inf 99.0%

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

      if -1 < x < 1

      1. Initial program 100.0%

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

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\left(-\frac{x + 1}{x - 1}\right)\right)} \]
        2. distribute-neg-frac100.0%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    Alternative 7: 97.9% accurate, 1.0× speedup?

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

      1. Initial program 7.6%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg7.6%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\left(-\frac{x + 1}{x - 1}\right)\right)} \]
        2. distribute-neg-frac7.6%

          \[\leadsto \frac{x}{x + 1} - \left(-\color{blue}{\frac{-\left(x + 1\right)}{x - 1}}\right) \]
        3. distribute-neg-in7.6%

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

          \[\leadsto \frac{x}{x + 1} - \left(-\frac{\color{blue}{\left(-x\right) - 1}}{x - 1}\right) \]
        5. distribute-frac-neg27.6%

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

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative7.6%

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

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval7.6%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub07.6%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-7.6%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub07.6%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative7.6%

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

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified7.6%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around inf 99.0%

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

      if -1 < x < 1

      1. Initial program 100.0%

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

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\left(-\frac{x + 1}{x - 1}\right)\right)} \]
        2. distribute-neg-frac100.0%

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 98.4%

        \[\leadsto \color{blue}{1} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification98.7%

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

    Alternative 8: 51.9% 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 49.8%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. remove-double-neg49.8%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\left(-\frac{x + 1}{x - 1}\right)\right)} \]
      2. distribute-neg-frac49.8%

        \[\leadsto \frac{x}{x + 1} - \left(-\color{blue}{\frac{-\left(x + 1\right)}{x - 1}}\right) \]
      3. distribute-neg-in49.8%

        \[\leadsto \frac{x}{x + 1} - \left(-\frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{x - 1}\right) \]
      4. sub-neg49.8%

        \[\leadsto \frac{x}{x + 1} - \left(-\frac{\color{blue}{\left(-x\right) - 1}}{x - 1}\right) \]
      5. distribute-frac-neg249.8%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
      6. sub-neg49.8%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
      7. +-commutative49.8%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
      8. unsub-neg49.8%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
      9. metadata-eval49.8%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
      10. neg-sub049.8%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
      11. associate-+l-49.8%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
      12. neg-sub049.8%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
      13. +-commutative49.8%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
      14. unsub-neg49.8%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
    3. Simplified49.8%

      \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 46.9%

      \[\leadsto \color{blue}{1} \]
    6. Final simplification46.9%

      \[\leadsto 1 \]
    7. Add Preprocessing

    Reproduce

    ?
    herbie shell --seed 2024078 
    (FPCore (x)
      :name "Asymptote C"
      :precision binary64
      (- (/ x (+ x 1.0)) (/ (+ x 1.0) (- x 1.0))))