Asymptote C

Percentage Accurate: 54.2% → 99.7%
Time: 9.1s
Alternatives: 11
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 11 alternatives:

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

Initial Program: 54.2% 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: 99.7% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + 1}\\ \mathbf{if}\;t\_0 + \frac{-1 - x}{x + -1} \leq 0.001:\\ \;\;\;\;\frac{\frac{-1 + \frac{-3 + \frac{-1}{x}}{x}}{x} - 3}{x}\\ \mathbf{else}:\\ \;\;\;\;\left(t\_0 + \frac{-1}{x + -1}\right) + \frac{x}{1 - x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (/ x (+ x 1.0))))
   (if (<= (+ t_0 (/ (- -1.0 x) (+ x -1.0))) 0.001)
     (/ (- (/ (+ -1.0 (/ (+ -3.0 (/ -1.0 x)) x)) x) 3.0) x)
     (+ (+ t_0 (/ -1.0 (+ x -1.0))) (/ x (- 1.0 x))))))
double code(double x) {
	double t_0 = x / (x + 1.0);
	double tmp;
	if ((t_0 + ((-1.0 - x) / (x + -1.0))) <= 0.001) {
		tmp = (((-1.0 + ((-3.0 + (-1.0 / x)) / x)) / x) - 3.0) / x;
	} else {
		tmp = (t_0 + (-1.0 / (x + -1.0))) + (x / (1.0 - x));
	}
	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)))) <= 0.001d0) then
        tmp = ((((-1.0d0) + (((-3.0d0) + ((-1.0d0) / x)) / x)) / x) - 3.0d0) / x
    else
        tmp = (t_0 + ((-1.0d0) / (x + (-1.0d0)))) + (x / (1.0d0 - x))
    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))) <= 0.001) {
		tmp = (((-1.0 + ((-3.0 + (-1.0 / x)) / x)) / x) - 3.0) / x;
	} else {
		tmp = (t_0 + (-1.0 / (x + -1.0))) + (x / (1.0 - x));
	}
	return tmp;
}
def code(x):
	t_0 = x / (x + 1.0)
	tmp = 0
	if (t_0 + ((-1.0 - x) / (x + -1.0))) <= 0.001:
		tmp = (((-1.0 + ((-3.0 + (-1.0 / x)) / x)) / x) - 3.0) / x
	else:
		tmp = (t_0 + (-1.0 / (x + -1.0))) + (x / (1.0 - x))
	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))) <= 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(Float64(t_0 + Float64(-1.0 / Float64(x + -1.0))) + Float64(x / Float64(1.0 - x)));
	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))) <= 0.001)
		tmp = (((-1.0 + ((-3.0 + (-1.0 / x)) / x)) / x) - 3.0) / x;
	else
		tmp = (t_0 + (-1.0 / (x + -1.0))) + (x / (1.0 - x));
	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], 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[(N[(t$95$0 + N[(-1.0 / N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(x / N[(1.0 - x), $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 0.001:\\
\;\;\;\;\frac{\frac{-1 + \frac{-3 + \frac{-1}{x}}{x}}{x} - 3}{x}\\

\mathbf{else}:\\
\;\;\;\;\left(t\_0 + \frac{-1}{x + -1}\right) + \frac{x}{1 - x}\\


\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 7.4%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. remove-double-neg7.4%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
      2. distribute-neg-in7.4%

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

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

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
      5. distribute-frac-neg27.4%

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

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
      7. +-commutative7.4%

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

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
      9. metadata-eval7.4%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
      10. neg-sub07.4%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
      11. associate-+l-7.4%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
      12. neg-sub07.4%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
      13. +-commutative7.4%

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

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
    3. Simplified7.4%

      \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
    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 99.9%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg99.9%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
        2. distribute-neg-in99.9%

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

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
        4. distribute-frac-neg99.9%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
        5. distribute-frac-neg299.9%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg99.9%

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

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg99.9%

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

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub099.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-99.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub099.9%

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

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg99.9%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified99.9%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Step-by-step derivation
        1. div-sub100.0%

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

          \[\leadsto \color{blue}{\left(\frac{x}{x + 1} - \frac{-1}{1 - x}\right) + \frac{x}{1 - x}} \]
        3. frac-2neg100.0%

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

          \[\leadsto \left(\frac{x}{x + 1} - \frac{\color{blue}{1}}{-\left(1 - x\right)}\right) + \frac{x}{1 - x} \]
        5. flip--99.9%

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

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

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

          \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{-\frac{-1 \cdot -1 - x \cdot x}{\color{blue}{x + 1}}}\right) + \frac{x}{1 - x} \]
        9. distribute-neg-frac299.9%

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

          \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{\frac{-1 \cdot -1 - x \cdot x}{-\color{blue}{\left(1 + x\right)}}}\right) + \frac{x}{1 - x} \]
        11. distribute-neg-in99.9%

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

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

          \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{\frac{-1 \cdot -1 - x \cdot x}{\color{blue}{-1 - x}}}\right) + \frac{x}{1 - x} \]
        14. flip-+100.0%

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

          \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{\color{blue}{x + -1}}\right) + \frac{x}{1 - x} \]
      6. Applied egg-rr100.0%

        \[\leadsto \color{blue}{\left(\frac{x}{x + 1} - \frac{1}{x + -1}\right) + \frac{x}{1 - x}} \]
    7. Recombined 2 regimes into one program.
    8. Final simplification99.9%

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

    Alternative 2: 99.7% accurate, 0.4× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + 1} + \frac{-1 - x}{x + -1}\\ \mathbf{if}\;t\_0 \leq 0.001:\\ \;\;\;\;\frac{\frac{-1 + \frac{-3 + \frac{-1}{x}}{x}}{x} - 3}{x}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (let* ((t_0 (+ (/ x (+ x 1.0)) (/ (- -1.0 x) (+ x -1.0)))))
       (if (<= t_0 0.001)
         (/ (- (/ (+ -1.0 (/ (+ -3.0 (/ -1.0 x)) x)) x) 3.0) x)
         t_0)))
    double code(double x) {
    	double t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0));
    	double tmp;
    	if (t_0 <= 0.001) {
    		tmp = (((-1.0 + ((-3.0 + (-1.0 / x)) / x)) / x) - 3.0) / x;
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        real(8) :: t_0
        real(8) :: tmp
        t_0 = (x / (x + 1.0d0)) + (((-1.0d0) - x) / (x + (-1.0d0)))
        if (t_0 <= 0.001d0) then
            tmp = ((((-1.0d0) + (((-3.0d0) + ((-1.0d0) / x)) / x)) / x) - 3.0d0) / x
        else
            tmp = t_0
        end if
        code = tmp
    end function
    
    public static double code(double x) {
    	double t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0));
    	double tmp;
    	if (t_0 <= 0.001) {
    		tmp = (((-1.0 + ((-3.0 + (-1.0 / x)) / x)) / x) - 3.0) / x;
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    def code(x):
    	t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0))
    	tmp = 0
    	if t_0 <= 0.001:
    		tmp = (((-1.0 + ((-3.0 + (-1.0 / x)) / x)) / x) - 3.0) / x
    	else:
    		tmp = t_0
    	return tmp
    
    function code(x)
    	t_0 = Float64(Float64(x / Float64(x + 1.0)) + Float64(Float64(-1.0 - x) / Float64(x + -1.0)))
    	tmp = 0.0
    	if (t_0 <= 0.001)
    		tmp = Float64(Float64(Float64(Float64(-1.0 + Float64(Float64(-3.0 + Float64(-1.0 / x)) / x)) / x) - 3.0) / x);
    	else
    		tmp = t_0;
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0));
    	tmp = 0.0;
    	if (t_0 <= 0.001)
    		tmp = (((-1.0 + ((-3.0 + (-1.0 / x)) / x)) / x) - 3.0) / x;
    	else
    		tmp = t_0;
    	end
    	tmp_2 = tmp;
    end
    
    code[x_] := Block[{t$95$0 = N[(N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] + N[(N[(-1.0 - x), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 0.001], N[(N[(N[(N[(-1.0 + N[(N[(-3.0 + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision] - 3.0), $MachinePrecision] / x), $MachinePrecision], t$95$0]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := \frac{x}{x + 1} + \frac{-1 - x}{x + -1}\\
    \mathbf{if}\;t\_0 \leq 0.001:\\
    \;\;\;\;\frac{\frac{-1 + \frac{-3 + \frac{-1}{x}}{x}}{x} - 3}{x}\\
    
    \mathbf{else}:\\
    \;\;\;\;t\_0\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64)))) < 1e-3

      1. Initial program 7.4%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg7.4%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
        2. distribute-neg-in7.4%

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

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

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
        5. distribute-frac-neg27.4%

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

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative7.4%

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

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval7.4%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub07.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-7.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub07.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative7.4%

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

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified7.4%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      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 99.9%

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

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

      Alternative 3: 99.3% accurate, 0.4× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + 1} + \frac{-1 - x}{x + -1}\\ \mathbf{if}\;t\_0 \leq 0:\\ \;\;\;\;\frac{-3 - \frac{1 + \frac{3}{x}}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
      (FPCore (x)
       :precision binary64
       (let* ((t_0 (+ (/ x (+ x 1.0)) (/ (- -1.0 x) (+ x -1.0)))))
         (if (<= t_0 0.0) (/ (- -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 <= 0.0) {
      		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 <= 0.0d0) 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 <= 0.0) {
      		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 <= 0.0:
      		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 <= 0.0)
      		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 <= 0.0)
      		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, 0.0], 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 0:\\
      \;\;\;\;\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)))) < 0.0

        1. Initial program 6.7%

          \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
        2. Step-by-step derivation
          1. remove-double-neg6.7%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
          2. distribute-neg-in6.7%

            \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
          3. sub-neg6.7%

            \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
          4. distribute-frac-neg6.7%

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
          5. distribute-frac-neg26.7%

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
          6. sub-neg6.7%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
          7. +-commutative6.7%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
          8. unsub-neg6.7%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
          9. metadata-eval6.7%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
          10. neg-sub06.7%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
          11. associate-+l-6.7%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
          12. neg-sub06.7%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
          13. +-commutative6.7%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
          14. unsub-neg6.7%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
        3. Simplified6.7%

          \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
        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. mul-1-neg100.0%

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

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

            \[\leadsto \frac{-3 - \frac{1 + \color{blue}{\frac{3 \cdot 1}{x}}}{x}}{x} \]
          7. 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 0.0 < (-.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 99.9%

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

        \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{x + 1} + \frac{-1 - x}{x + -1} \leq 0:\\ \;\;\;\;\frac{-3 - \frac{1 + \frac{3}{x}}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{x + 1} + \frac{-1 - x}{x + -1}\\ \end{array} \]
      5. Add Preprocessing

      Alternative 4: 99.2% accurate, 0.6× speedup?

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

        1. Initial program 7.4%

          \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
        2. Step-by-step derivation
          1. remove-double-neg7.4%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
          2. distribute-neg-in7.4%

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

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

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
          5. distribute-frac-neg27.4%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
          7. +-commutative7.4%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
          9. metadata-eval7.4%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
          10. neg-sub07.4%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
          11. associate-+l-7.4%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
          12. neg-sub07.4%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
          13. +-commutative7.4%

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

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
        3. Simplified7.4%

          \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
        4. Add Preprocessing
        5. Taylor expanded in x around inf 99.8%

          \[\leadsto \color{blue}{\frac{-1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x} - 3}{x}} \]
        6. Step-by-step derivation
          1. sub-neg99.8%

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

            \[\leadsto \frac{-1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x} + \color{blue}{-3}}{x} \]
          3. +-commutative99.8%

            \[\leadsto \frac{\color{blue}{-3 + -1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x}}}{x} \]
          4. mul-1-neg99.8%

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

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

            \[\leadsto \frac{-3 - \frac{1 + \color{blue}{\frac{3 \cdot 1}{x}}}{x}}{x} \]
          7. metadata-eval99.8%

            \[\leadsto \frac{-3 - \frac{1 + \frac{\color{blue}{3}}{x}}{x}}{x} \]
        7. Simplified99.8%

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

        if -1 < x < 1

        1. Initial program 99.9%

          \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
        2. Step-by-step derivation
          1. remove-double-neg99.9%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
          2. distribute-neg-in99.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
          4. distribute-frac-neg99.9%

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
          5. distribute-frac-neg299.9%

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
          6. sub-neg99.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
          8. unsub-neg99.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
          10. neg-sub099.9%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
          11. associate-+l-99.9%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
          12. neg-sub099.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
          14. unsub-neg99.9%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
        3. Simplified99.9%

          \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
        4. Add Preprocessing
        5. Step-by-step derivation
          1. div-sub100.0%

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

            \[\leadsto \color{blue}{\left(\frac{x}{x + 1} - \frac{-1}{1 - x}\right) + \frac{x}{1 - x}} \]
          3. frac-2neg100.0%

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

            \[\leadsto \left(\frac{x}{x + 1} - \frac{\color{blue}{1}}{-\left(1 - x\right)}\right) + \frac{x}{1 - x} \]
          5. flip--99.9%

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

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

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

            \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{-\frac{-1 \cdot -1 - x \cdot x}{\color{blue}{x + 1}}}\right) + \frac{x}{1 - x} \]
          9. distribute-neg-frac299.9%

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

            \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{\frac{-1 \cdot -1 - x \cdot x}{-\color{blue}{\left(1 + x\right)}}}\right) + \frac{x}{1 - x} \]
          11. distribute-neg-in99.9%

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

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

            \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{\frac{-1 \cdot -1 - x \cdot x}{\color{blue}{-1 - x}}}\right) + \frac{x}{1 - x} \]
          14. flip-+100.0%

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

            \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{\color{blue}{x + -1}}\right) + \frac{x}{1 - x} \]
        6. Applied egg-rr100.0%

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

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

            \[\leadsto \color{blue}{\left(\frac{x}{1 - x} + \frac{x}{x + 1}\right) - \frac{1}{x + -1}} \]
        8. Applied egg-rr100.0%

          \[\leadsto \color{blue}{\left(\frac{x}{1 - x} + \frac{x}{x + 1}\right) - \frac{1}{x + -1}} \]
        9. Taylor expanded in x around 0 99.0%

          \[\leadsto \color{blue}{2 \cdot x} - \frac{1}{x + -1} \]
        10. Step-by-step derivation
          1. *-commutative99.0%

            \[\leadsto \color{blue}{x \cdot 2} - \frac{1}{x + -1} \]
        11. Simplified99.0%

          \[\leadsto \color{blue}{x \cdot 2} - \frac{1}{x + -1} \]
        12. Taylor expanded in x around 0 99.0%

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

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

      Alternative 5: 99.0% accurate, 0.6× speedup?

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

        1. Initial program 7.4%

          \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
        2. Step-by-step derivation
          1. remove-double-neg7.4%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
          2. distribute-neg-in7.4%

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

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

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
          5. distribute-frac-neg27.4%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
          7. +-commutative7.4%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
          9. metadata-eval7.4%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
          10. neg-sub07.4%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
          11. associate-+l-7.4%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
          12. neg-sub07.4%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
          13. +-commutative7.4%

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

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
        3. Simplified7.4%

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

          \[\leadsto \color{blue}{-1 \cdot \frac{3 + \frac{1}{x}}{x}} \]
        6. Step-by-step derivation
          1. associate-*r/99.4%

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

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

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

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

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

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

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

        if -1 < x < 1

        1. Initial program 99.9%

          \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
        2. Step-by-step derivation
          1. remove-double-neg99.9%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
          2. distribute-neg-in99.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
          4. distribute-frac-neg99.9%

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
          5. distribute-frac-neg299.9%

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
          6. sub-neg99.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
          8. unsub-neg99.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
          10. neg-sub099.9%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
          11. associate-+l-99.9%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
          12. neg-sub099.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
          14. unsub-neg99.9%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
        3. Simplified99.9%

          \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
        4. Add Preprocessing
        5. Step-by-step derivation
          1. div-sub100.0%

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

            \[\leadsto \color{blue}{\left(\frac{x}{x + 1} - \frac{-1}{1 - x}\right) + \frac{x}{1 - x}} \]
          3. frac-2neg100.0%

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

            \[\leadsto \left(\frac{x}{x + 1} - \frac{\color{blue}{1}}{-\left(1 - x\right)}\right) + \frac{x}{1 - x} \]
          5. flip--99.9%

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

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

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

            \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{-\frac{-1 \cdot -1 - x \cdot x}{\color{blue}{x + 1}}}\right) + \frac{x}{1 - x} \]
          9. distribute-neg-frac299.9%

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

            \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{\frac{-1 \cdot -1 - x \cdot x}{-\color{blue}{\left(1 + x\right)}}}\right) + \frac{x}{1 - x} \]
          11. distribute-neg-in99.9%

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

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

            \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{\frac{-1 \cdot -1 - x \cdot x}{\color{blue}{-1 - x}}}\right) + \frac{x}{1 - x} \]
          14. flip-+100.0%

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

            \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{\color{blue}{x + -1}}\right) + \frac{x}{1 - x} \]
        6. Applied egg-rr100.0%

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

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

            \[\leadsto \color{blue}{\left(\frac{x}{1 - x} + \frac{x}{x + 1}\right) - \frac{1}{x + -1}} \]
        8. Applied egg-rr100.0%

          \[\leadsto \color{blue}{\left(\frac{x}{1 - x} + \frac{x}{x + 1}\right) - \frac{1}{x + -1}} \]
        9. Taylor expanded in x around 0 99.0%

          \[\leadsto \color{blue}{2 \cdot x} - \frac{1}{x + -1} \]
        10. Step-by-step derivation
          1. *-commutative99.0%

            \[\leadsto \color{blue}{x \cdot 2} - \frac{1}{x + -1} \]
        11. Simplified99.0%

          \[\leadsto \color{blue}{x \cdot 2} - \frac{1}{x + -1} \]
        12. Taylor expanded in x around 0 99.0%

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

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

      Alternative 6: 99.0% 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 7.4%

          \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
        2. Step-by-step derivation
          1. remove-double-neg7.4%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
          2. distribute-neg-in7.4%

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

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

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
          5. distribute-frac-neg27.4%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
          7. +-commutative7.4%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
          9. metadata-eval7.4%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
          10. neg-sub07.4%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
          11. associate-+l-7.4%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
          12. neg-sub07.4%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
          13. +-commutative7.4%

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

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
        3. Simplified7.4%

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

          \[\leadsto \color{blue}{-1 \cdot \frac{3 + \frac{1}{x}}{x}} \]
        6. Step-by-step derivation
          1. associate-*r/99.4%

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

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

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

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

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

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

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

        if -1 < x < 1

        1. Initial program 99.9%

          \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
        2. Step-by-step derivation
          1. remove-double-neg99.9%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
          2. distribute-neg-in99.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
          4. distribute-frac-neg99.9%

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
          5. distribute-frac-neg299.9%

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
          6. sub-neg99.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
          8. unsub-neg99.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
          10. neg-sub099.9%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
          11. associate-+l-99.9%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
          12. neg-sub099.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
          14. unsub-neg99.9%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
        3. Simplified99.9%

          \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
        4. Add Preprocessing
        5. Taylor expanded in x around 0 99.0%

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

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

      Alternative 7: 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 7.4%

          \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
        2. Step-by-step derivation
          1. remove-double-neg7.4%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
          2. distribute-neg-in7.4%

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

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

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
          5. distribute-frac-neg27.4%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
          7. +-commutative7.4%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
          9. metadata-eval7.4%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
          10. neg-sub07.4%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
          11. associate-+l-7.4%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
          12. neg-sub07.4%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
          13. +-commutative7.4%

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

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
        3. Simplified7.4%

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

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

        if -1 < x < 1

        1. Initial program 99.9%

          \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
        2. Step-by-step derivation
          1. remove-double-neg99.9%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
          2. distribute-neg-in99.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
          4. distribute-frac-neg99.9%

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
          5. distribute-frac-neg299.9%

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
          6. sub-neg99.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
          8. unsub-neg99.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
          10. neg-sub099.9%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
          11. associate-+l-99.9%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
          12. neg-sub099.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
          14. unsub-neg99.9%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
        3. Simplified99.9%

          \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
        4. Add Preprocessing
        5. Taylor expanded in x around 0 99.0%

          \[\leadsto \color{blue}{1 + x \cdot \left(3 + x\right)} \]
      3. Recombined 2 regimes into one program.
      4. Final simplification98.9%

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

      Alternative 8: 99.7% accurate, 0.8× speedup?

      \[\begin{array}{l} \\ \frac{2}{\frac{x + 1}{x} \cdot \left(1 - x\right)} + \frac{-1}{x + -1} \end{array} \]
      (FPCore (x)
       :precision binary64
       (+ (/ 2.0 (* (/ (+ x 1.0) x) (- 1.0 x))) (/ -1.0 (+ x -1.0))))
      double code(double x) {
      	return (2.0 / (((x + 1.0) / x) * (1.0 - x))) + (-1.0 / (x + -1.0));
      }
      
      real(8) function code(x)
          real(8), intent (in) :: x
          code = (2.0d0 / (((x + 1.0d0) / x) * (1.0d0 - x))) + ((-1.0d0) / (x + (-1.0d0)))
      end function
      
      public static double code(double x) {
      	return (2.0 / (((x + 1.0) / x) * (1.0 - x))) + (-1.0 / (x + -1.0));
      }
      
      def code(x):
      	return (2.0 / (((x + 1.0) / x) * (1.0 - x))) + (-1.0 / (x + -1.0))
      
      function code(x)
      	return Float64(Float64(2.0 / Float64(Float64(Float64(x + 1.0) / x) * Float64(1.0 - x))) + Float64(-1.0 / Float64(x + -1.0)))
      end
      
      function tmp = code(x)
      	tmp = (2.0 / (((x + 1.0) / x) * (1.0 - x))) + (-1.0 / (x + -1.0));
      end
      
      code[x_] := N[(N[(2.0 / N[(N[(N[(x + 1.0), $MachinePrecision] / x), $MachinePrecision] * N[(1.0 - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-1.0 / N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \frac{2}{\frac{x + 1}{x} \cdot \left(1 - x\right)} + \frac{-1}{x + -1}
      \end{array}
      
      Derivation
      1. Initial program 58.4%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
        2. distribute-neg-in58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
        3. sub-neg58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
        4. distribute-frac-neg58.4%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
        5. distribute-frac-neg258.4%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub058.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub058.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified58.4%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Step-by-step derivation
        1. div-sub58.4%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(\frac{-1}{1 - x} - \frac{x}{1 - x}\right)} \]
        2. associate--r-58.4%

          \[\leadsto \color{blue}{\left(\frac{x}{x + 1} - \frac{-1}{1 - x}\right) + \frac{x}{1 - x}} \]
        3. frac-2neg58.4%

          \[\leadsto \left(\frac{x}{x + 1} - \color{blue}{\frac{--1}{-\left(1 - x\right)}}\right) + \frac{x}{1 - x} \]
        4. metadata-eval58.4%

          \[\leadsto \left(\frac{x}{x + 1} - \frac{\color{blue}{1}}{-\left(1 - x\right)}\right) + \frac{x}{1 - x} \]
        5. flip--58.4%

          \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{-\color{blue}{\frac{1 \cdot 1 - x \cdot x}{1 + x}}}\right) + \frac{x}{1 - x} \]
        6. metadata-eval58.4%

          \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{-\frac{\color{blue}{1} - x \cdot x}{1 + x}}\right) + \frac{x}{1 - x} \]
        7. metadata-eval58.4%

          \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{-\frac{\color{blue}{-1 \cdot -1} - x \cdot x}{1 + x}}\right) + \frac{x}{1 - x} \]
        8. +-commutative58.4%

          \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{-\frac{-1 \cdot -1 - x \cdot x}{\color{blue}{x + 1}}}\right) + \frac{x}{1 - x} \]
        9. distribute-neg-frac258.4%

          \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{\color{blue}{\frac{-1 \cdot -1 - x \cdot x}{-\left(x + 1\right)}}}\right) + \frac{x}{1 - x} \]
        10. +-commutative58.4%

          \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{\frac{-1 \cdot -1 - x \cdot x}{-\color{blue}{\left(1 + x\right)}}}\right) + \frac{x}{1 - x} \]
        11. distribute-neg-in58.4%

          \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{\frac{-1 \cdot -1 - x \cdot x}{\color{blue}{\left(-1\right) + \left(-x\right)}}}\right) + \frac{x}{1 - x} \]
        12. metadata-eval58.4%

          \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{\frac{-1 \cdot -1 - x \cdot x}{\color{blue}{-1} + \left(-x\right)}}\right) + \frac{x}{1 - x} \]
        13. sub-neg58.4%

          \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{\frac{-1 \cdot -1 - x \cdot x}{\color{blue}{-1 - x}}}\right) + \frac{x}{1 - x} \]
        14. flip-+58.4%

          \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{\color{blue}{-1 + x}}\right) + \frac{x}{1 - x} \]
        15. +-commutative58.4%

          \[\leadsto \left(\frac{x}{x + 1} - \frac{1}{\color{blue}{x + -1}}\right) + \frac{x}{1 - x} \]
      6. Applied egg-rr58.4%

        \[\leadsto \color{blue}{\left(\frac{x}{x + 1} - \frac{1}{x + -1}\right) + \frac{x}{1 - x}} \]
      7. Step-by-step derivation
        1. +-commutative58.4%

          \[\leadsto \color{blue}{\frac{x}{1 - x} + \left(\frac{x}{x + 1} - \frac{1}{x + -1}\right)} \]
        2. associate-+r-63.7%

          \[\leadsto \color{blue}{\left(\frac{x}{1 - x} + \frac{x}{x + 1}\right) - \frac{1}{x + -1}} \]
      8. Applied egg-rr63.7%

        \[\leadsto \color{blue}{\left(\frac{x}{1 - x} + \frac{x}{x + 1}\right) - \frac{1}{x + -1}} \]
      9. Step-by-step derivation
        1. +-commutative63.7%

          \[\leadsto \color{blue}{\left(\frac{x}{x + 1} + \frac{x}{1 - x}\right)} - \frac{1}{x + -1} \]
        2. clear-num63.7%

          \[\leadsto \left(\color{blue}{\frac{1}{\frac{x + 1}{x}}} + \frac{x}{1 - x}\right) - \frac{1}{x + -1} \]
        3. frac-add64.1%

          \[\leadsto \color{blue}{\frac{1 \cdot \left(1 - x\right) + \frac{x + 1}{x} \cdot x}{\frac{x + 1}{x} \cdot \left(1 - x\right)}} - \frac{1}{x + -1} \]
        4. *-un-lft-identity64.1%

          \[\leadsto \frac{\color{blue}{\left(1 - x\right)} + \frac{x + 1}{x} \cdot x}{\frac{x + 1}{x} \cdot \left(1 - x\right)} - \frac{1}{x + -1} \]
      10. Applied egg-rr64.1%

        \[\leadsto \color{blue}{\frac{\left(1 - x\right) + \frac{x + 1}{x} \cdot x}{\frac{x + 1}{x} \cdot \left(1 - x\right)}} - \frac{1}{x + -1} \]
      11. Taylor expanded in x around 0 99.7%

        \[\leadsto \frac{\color{blue}{2}}{\frac{x + 1}{x} \cdot \left(1 - x\right)} - \frac{1}{x + -1} \]
      12. Final simplification99.7%

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

      Alternative 9: 98.4% 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 7.4%

          \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
        2. Step-by-step derivation
          1. remove-double-neg7.4%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
          2. distribute-neg-in7.4%

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

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

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
          5. distribute-frac-neg27.4%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
          7. +-commutative7.4%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
          9. metadata-eval7.4%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
          10. neg-sub07.4%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
          11. associate-+l-7.4%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
          12. neg-sub07.4%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
          13. +-commutative7.4%

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

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
        3. Simplified7.4%

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

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

        if -1 < x < 1

        1. Initial program 99.9%

          \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
        2. Step-by-step derivation
          1. remove-double-neg99.9%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
          2. distribute-neg-in99.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
          4. distribute-frac-neg99.9%

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
          5. distribute-frac-neg299.9%

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
          6. sub-neg99.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
          8. unsub-neg99.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
          10. neg-sub099.9%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
          11. associate-+l-99.9%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
          12. neg-sub099.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
          14. unsub-neg99.9%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
        3. Simplified99.9%

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

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

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

      Alternative 10: 97.8% 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 7.4%

          \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
        2. Step-by-step derivation
          1. remove-double-neg7.4%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
          2. distribute-neg-in7.4%

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

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

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
          5. distribute-frac-neg27.4%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
          7. +-commutative7.4%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
          9. metadata-eval7.4%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
          10. neg-sub07.4%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
          11. associate-+l-7.4%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
          12. neg-sub07.4%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
          13. +-commutative7.4%

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

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
        3. Simplified7.4%

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

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

        if -1 < x < 1

        1. Initial program 99.9%

          \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
        2. Step-by-step derivation
          1. remove-double-neg99.9%

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
          2. distribute-neg-in99.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
          4. distribute-frac-neg99.9%

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
          5. distribute-frac-neg299.9%

            \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
          6. sub-neg99.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
          8. unsub-neg99.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
          10. neg-sub099.9%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
          11. associate-+l-99.9%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
          12. neg-sub099.9%

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

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
          14. unsub-neg99.9%

            \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
        3. Simplified99.9%

          \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
        4. Add Preprocessing
        5. Taylor expanded in x around 0 96.5%

          \[\leadsto \color{blue}{1} \]
      3. Recombined 2 regimes into one program.
      4. Final simplification97.5%

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

      Alternative 11: 50.6% 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 58.4%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Step-by-step derivation
        1. remove-double-neg58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
        2. distribute-neg-in58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
        3. sub-neg58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
        4. distribute-frac-neg58.4%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
        5. distribute-frac-neg258.4%

          \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
        6. sub-neg58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
        7. +-commutative58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
        8. unsub-neg58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
        9. metadata-eval58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
        10. neg-sub058.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
        11. associate-+l-58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
        12. neg-sub058.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
        13. +-commutative58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
        14. unsub-neg58.4%

          \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
      3. Simplified58.4%

        \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 54.8%

        \[\leadsto \color{blue}{1} \]
      6. Add Preprocessing

      Reproduce

      ?
      herbie shell --seed 2024155 
      (FPCore (x)
        :name "Asymptote C"
        :precision binary64
        (- (/ x (+ x 1.0)) (/ (+ x 1.0) (- x 1.0))))