Asymptote B

Percentage Accurate: 100.0% → 100.0%
Time: 5.5s
Alternatives: 7
Speedup: 1.0×

Specification

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

\\
\frac{1}{x - 1} + \frac{x}{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 7 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: 100.0% accurate, 1.0× speedup?

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

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

Alternative 1: 100.0% accurate, 1.0× speedup?

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

\\
\frac{x}{1 + x} + \frac{1}{x + -1}
\end{array}
Derivation
  1. Initial program 100.0%

    \[\frac{1}{x - 1} + \frac{x}{x + 1} \]
  2. Add Preprocessing
  3. Final simplification100.0%

    \[\leadsto \frac{x}{1 + x} + \frac{1}{x + -1} \]
  4. Add Preprocessing

Alternative 2: 98.9% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.92:\\ \;\;\;\;1\\ \mathbf{elif}\;x \leq 1:\\ \;\;\;\;\frac{x}{1 + x} + \left(-1 - x\right)\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.92) 1.0 (if (<= x 1.0) (+ (/ x (+ 1.0 x)) (- -1.0 x)) 1.0)))
double code(double x) {
	double tmp;
	if (x <= -1.92) {
		tmp = 1.0;
	} else if (x <= 1.0) {
		tmp = (x / (1.0 + x)) + (-1.0 - x);
	} else {
		tmp = 1.0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1.92d0)) then
        tmp = 1.0d0
    else if (x <= 1.0d0) then
        tmp = (x / (1.0d0 + x)) + ((-1.0d0) - x)
    else
        tmp = 1.0d0
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -1.92) {
		tmp = 1.0;
	} else if (x <= 1.0) {
		tmp = (x / (1.0 + x)) + (-1.0 - x);
	} else {
		tmp = 1.0;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -1.92:
		tmp = 1.0
	elif x <= 1.0:
		tmp = (x / (1.0 + x)) + (-1.0 - x)
	else:
		tmp = 1.0
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -1.92)
		tmp = 1.0;
	elseif (x <= 1.0)
		tmp = Float64(Float64(x / Float64(1.0 + x)) + Float64(-1.0 - x));
	else
		tmp = 1.0;
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1.92)
		tmp = 1.0;
	elseif (x <= 1.0)
		tmp = (x / (1.0 + x)) + (-1.0 - x);
	else
		tmp = 1.0;
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -1.92], 1.0, If[LessEqual[x, 1.0], N[(N[(x / N[(1.0 + x), $MachinePrecision]), $MachinePrecision] + N[(-1.0 - x), $MachinePrecision]), $MachinePrecision], 1.0]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.92:\\
\;\;\;\;1\\

\mathbf{elif}\;x \leq 1:\\
\;\;\;\;\frac{x}{1 + x} + \left(-1 - x\right)\\

\mathbf{else}:\\
\;\;\;\;1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.9199999999999999 or 1 < x

    1. Initial program 100.0%

      \[\frac{1}{x - 1} + \frac{x}{x + 1} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

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

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

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

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

      \[\leadsto \color{blue}{\frac{x}{1 + x} + \frac{1}{x + -1}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \color{blue}{\frac{1}{x + -1} + \frac{x}{1 + x}} \]
      2. frac-2neg100.0%

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

        \[\leadsto \frac{\color{blue}{-1}}{-\left(x + -1\right)} + \frac{x}{1 + x} \]
      4. clear-num100.0%

        \[\leadsto \frac{-1}{-\left(x + -1\right)} + \color{blue}{\frac{1}{\frac{1 + x}{x}}} \]
      5. frac-add100.0%

        \[\leadsto \color{blue}{\frac{-1 \cdot \frac{1 + x}{x} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}}} \]
      6. fma-def100.0%

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

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(-\color{blue}{\left(-1 + x\right)}\right) \cdot 1\right)}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}} \]
      8. distribute-neg-in100.0%

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

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(\color{blue}{1} + \left(-x\right)\right) \cdot 1\right)}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}} \]
      10. sub-neg100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \color{blue}{\left(1 - x\right)} \cdot 1\right)}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}} \]
      11. +-commutative100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\left(-\color{blue}{\left(-1 + x\right)}\right) \cdot \frac{1 + x}{x}} \]
      12. distribute-neg-in100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\color{blue}{\left(\left(--1\right) + \left(-x\right)\right)} \cdot \frac{1 + x}{x}} \]
      13. metadata-eval100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\left(\color{blue}{1} + \left(-x\right)\right) \cdot \frac{1 + x}{x}} \]
      14. sub-neg100.0%

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

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}}} \]
    7. Step-by-step derivation
      1. fma-udef100.0%

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

        \[\leadsto \frac{\color{blue}{\frac{1 + x}{x} \cdot -1} + \left(1 - x\right) \cdot 1}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      3. *-rgt-identity100.0%

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

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

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

        \[\leadsto \frac{1 - \left(x - \color{blue}{-1 \cdot \frac{1 + x}{x}}\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      7. cancel-sign-sub-inv100.0%

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

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

        \[\leadsto \frac{1 - \left(x + \color{blue}{\frac{1 + x}{x} \cdot 1}\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      10. *-rgt-identity100.0%

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

        \[\leadsto \frac{1 - \left(x + \frac{\color{blue}{x + 1}}{x}\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      12. associate-*r/44.9%

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

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

        \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\frac{1 - x}{\frac{x}{\color{blue}{x + 1}}}} \]
    8. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1 - \left(x + \frac{x + 1}{x}\right)}{\frac{1 - x}{\frac{x}{x + 1}}}} \]
    9. Taylor expanded in x around 0 100.0%

      \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\color{blue}{-1 \cdot x + \frac{1}{x}}} \]
    10. Step-by-step derivation
      1. neg-mul-1100.0%

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

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

        \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\color{blue}{\frac{1}{x} - x}} \]
    11. Simplified100.0%

      \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\color{blue}{\frac{1}{x} - x}} \]
    12. Taylor expanded in x around inf 98.9%

      \[\leadsto \color{blue}{1} \]

    if -1.9199999999999999 < x < 1

    1. Initial program 100.0%

      \[\frac{1}{x - 1} + \frac{x}{x + 1} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

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

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

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

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

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

      \[\leadsto \frac{x}{1 + x} + \color{blue}{\left(-1 \cdot x - 1\right)} \]
    6. Step-by-step derivation
      1. sub-neg98.5%

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

        \[\leadsto \frac{x}{1 + x} + \left(-1 \cdot x + \color{blue}{-1}\right) \]
      3. neg-mul-198.5%

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

        \[\leadsto \frac{x}{1 + x} + \color{blue}{\left(-1 + \left(-x\right)\right)} \]
      5. unsub-neg98.5%

        \[\leadsto \frac{x}{1 + x} + \color{blue}{\left(-1 - x\right)} \]
    7. Simplified98.5%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.92:\\ \;\;\;\;1\\ \mathbf{elif}\;x \leq 1:\\ \;\;\;\;\frac{x}{1 + x} + \left(-1 - x\right)\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 98.9% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{1 + x}\\ \mathbf{if}\;x \leq -1.92:\\ \;\;\;\;1\\ \mathbf{elif}\;x \leq 1:\\ \;\;\;\;t\_0 + \left(-1 - x\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0 + \frac{1}{x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (/ x (+ 1.0 x))))
   (if (<= x -1.92) 1.0 (if (<= x 1.0) (+ t_0 (- -1.0 x)) (+ t_0 (/ 1.0 x))))))
double code(double x) {
	double t_0 = x / (1.0 + x);
	double tmp;
	if (x <= -1.92) {
		tmp = 1.0;
	} else if (x <= 1.0) {
		tmp = t_0 + (-1.0 - x);
	} else {
		tmp = t_0 + (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 / (1.0d0 + x)
    if (x <= (-1.92d0)) then
        tmp = 1.0d0
    else if (x <= 1.0d0) then
        tmp = t_0 + ((-1.0d0) - x)
    else
        tmp = t_0 + (1.0d0 / x)
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = x / (1.0 + x);
	double tmp;
	if (x <= -1.92) {
		tmp = 1.0;
	} else if (x <= 1.0) {
		tmp = t_0 + (-1.0 - x);
	} else {
		tmp = t_0 + (1.0 / x);
	}
	return tmp;
}
def code(x):
	t_0 = x / (1.0 + x)
	tmp = 0
	if x <= -1.92:
		tmp = 1.0
	elif x <= 1.0:
		tmp = t_0 + (-1.0 - x)
	else:
		tmp = t_0 + (1.0 / x)
	return tmp
function code(x)
	t_0 = Float64(x / Float64(1.0 + x))
	tmp = 0.0
	if (x <= -1.92)
		tmp = 1.0;
	elseif (x <= 1.0)
		tmp = Float64(t_0 + Float64(-1.0 - x));
	else
		tmp = Float64(t_0 + Float64(1.0 / x));
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = x / (1.0 + x);
	tmp = 0.0;
	if (x <= -1.92)
		tmp = 1.0;
	elseif (x <= 1.0)
		tmp = t_0 + (-1.0 - x);
	else
		tmp = t_0 + (1.0 / x);
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(x / N[(1.0 + x), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[x, -1.92], 1.0, If[LessEqual[x, 1.0], N[(t$95$0 + N[(-1.0 - x), $MachinePrecision]), $MachinePrecision], N[(t$95$0 + N[(1.0 / x), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x}{1 + x}\\
\mathbf{if}\;x \leq -1.92:\\
\;\;\;\;1\\

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

\mathbf{else}:\\
\;\;\;\;t\_0 + \frac{1}{x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -1.9199999999999999

    1. Initial program 100.0%

      \[\frac{1}{x - 1} + \frac{x}{x + 1} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

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

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

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

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

      \[\leadsto \color{blue}{\frac{x}{1 + x} + \frac{1}{x + -1}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \color{blue}{\frac{1}{x + -1} + \frac{x}{1 + x}} \]
      2. frac-2neg100.0%

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

        \[\leadsto \frac{\color{blue}{-1}}{-\left(x + -1\right)} + \frac{x}{1 + x} \]
      4. clear-num100.0%

        \[\leadsto \frac{-1}{-\left(x + -1\right)} + \color{blue}{\frac{1}{\frac{1 + x}{x}}} \]
      5. frac-add100.0%

        \[\leadsto \color{blue}{\frac{-1 \cdot \frac{1 + x}{x} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}}} \]
      6. fma-def100.0%

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

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(-\color{blue}{\left(-1 + x\right)}\right) \cdot 1\right)}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}} \]
      8. distribute-neg-in100.0%

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

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(\color{blue}{1} + \left(-x\right)\right) \cdot 1\right)}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}} \]
      10. sub-neg100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \color{blue}{\left(1 - x\right)} \cdot 1\right)}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}} \]
      11. +-commutative100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\left(-\color{blue}{\left(-1 + x\right)}\right) \cdot \frac{1 + x}{x}} \]
      12. distribute-neg-in100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\color{blue}{\left(\left(--1\right) + \left(-x\right)\right)} \cdot \frac{1 + x}{x}} \]
      13. metadata-eval100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\left(\color{blue}{1} + \left(-x\right)\right) \cdot \frac{1 + x}{x}} \]
      14. sub-neg100.0%

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

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}}} \]
    7. Step-by-step derivation
      1. fma-udef100.0%

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

        \[\leadsto \frac{\color{blue}{\frac{1 + x}{x} \cdot -1} + \left(1 - x\right) \cdot 1}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      3. *-rgt-identity100.0%

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

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

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

        \[\leadsto \frac{1 - \left(x - \color{blue}{-1 \cdot \frac{1 + x}{x}}\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      7. cancel-sign-sub-inv100.0%

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

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

        \[\leadsto \frac{1 - \left(x + \color{blue}{\frac{1 + x}{x} \cdot 1}\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      10. *-rgt-identity100.0%

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

        \[\leadsto \frac{1 - \left(x + \frac{\color{blue}{x + 1}}{x}\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      12. associate-*r/40.1%

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

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

        \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\frac{1 - x}{\frac{x}{\color{blue}{x + 1}}}} \]
    8. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1 - \left(x + \frac{x + 1}{x}\right)}{\frac{1 - x}{\frac{x}{x + 1}}}} \]
    9. Taylor expanded in x around 0 100.0%

      \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\color{blue}{-1 \cdot x + \frac{1}{x}}} \]
    10. Step-by-step derivation
      1. neg-mul-1100.0%

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

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

        \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\color{blue}{\frac{1}{x} - x}} \]
    11. Simplified100.0%

      \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\color{blue}{\frac{1}{x} - x}} \]
    12. Taylor expanded in x around inf 100.0%

      \[\leadsto \color{blue}{1} \]

    if -1.9199999999999999 < x < 1

    1. Initial program 100.0%

      \[\frac{1}{x - 1} + \frac{x}{x + 1} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

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

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

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

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

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

      \[\leadsto \frac{x}{1 + x} + \color{blue}{\left(-1 \cdot x - 1\right)} \]
    6. Step-by-step derivation
      1. sub-neg98.5%

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

        \[\leadsto \frac{x}{1 + x} + \left(-1 \cdot x + \color{blue}{-1}\right) \]
      3. neg-mul-198.5%

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

        \[\leadsto \frac{x}{1 + x} + \color{blue}{\left(-1 + \left(-x\right)\right)} \]
      5. unsub-neg98.5%

        \[\leadsto \frac{x}{1 + x} + \color{blue}{\left(-1 - x\right)} \]
    7. Simplified98.5%

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

    if 1 < x

    1. Initial program 100.0%

      \[\frac{1}{x - 1} + \frac{x}{x + 1} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

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

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

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

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

      \[\leadsto \color{blue}{\frac{x}{1 + x} + \frac{1}{x + -1}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 97.8%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.92:\\ \;\;\;\;1\\ \mathbf{elif}\;x \leq 1:\\ \;\;\;\;\frac{x}{1 + x} + \left(-1 - x\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{1 + x} + \frac{1}{x}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 98.9% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{1 + x}\\ \mathbf{if}\;x \leq -1.92:\\ \;\;\;\;1\\ \mathbf{elif}\;x \leq 1:\\ \;\;\;\;\left(-1 + t\_0\right) - x\\ \mathbf{else}:\\ \;\;\;\;t\_0 + \frac{1}{x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (/ x (+ 1.0 x))))
   (if (<= x -1.92) 1.0 (if (<= x 1.0) (- (+ -1.0 t_0) x) (+ t_0 (/ 1.0 x))))))
double code(double x) {
	double t_0 = x / (1.0 + x);
	double tmp;
	if (x <= -1.92) {
		tmp = 1.0;
	} else if (x <= 1.0) {
		tmp = (-1.0 + t_0) - x;
	} else {
		tmp = t_0 + (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 / (1.0d0 + x)
    if (x <= (-1.92d0)) then
        tmp = 1.0d0
    else if (x <= 1.0d0) then
        tmp = ((-1.0d0) + t_0) - x
    else
        tmp = t_0 + (1.0d0 / x)
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = x / (1.0 + x);
	double tmp;
	if (x <= -1.92) {
		tmp = 1.0;
	} else if (x <= 1.0) {
		tmp = (-1.0 + t_0) - x;
	} else {
		tmp = t_0 + (1.0 / x);
	}
	return tmp;
}
def code(x):
	t_0 = x / (1.0 + x)
	tmp = 0
	if x <= -1.92:
		tmp = 1.0
	elif x <= 1.0:
		tmp = (-1.0 + t_0) - x
	else:
		tmp = t_0 + (1.0 / x)
	return tmp
function code(x)
	t_0 = Float64(x / Float64(1.0 + x))
	tmp = 0.0
	if (x <= -1.92)
		tmp = 1.0;
	elseif (x <= 1.0)
		tmp = Float64(Float64(-1.0 + t_0) - x);
	else
		tmp = Float64(t_0 + Float64(1.0 / x));
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = x / (1.0 + x);
	tmp = 0.0;
	if (x <= -1.92)
		tmp = 1.0;
	elseif (x <= 1.0)
		tmp = (-1.0 + t_0) - x;
	else
		tmp = t_0 + (1.0 / x);
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(x / N[(1.0 + x), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[x, -1.92], 1.0, If[LessEqual[x, 1.0], N[(N[(-1.0 + t$95$0), $MachinePrecision] - x), $MachinePrecision], N[(t$95$0 + N[(1.0 / x), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x}{1 + x}\\
\mathbf{if}\;x \leq -1.92:\\
\;\;\;\;1\\

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

\mathbf{else}:\\
\;\;\;\;t\_0 + \frac{1}{x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -1.9199999999999999

    1. Initial program 100.0%

      \[\frac{1}{x - 1} + \frac{x}{x + 1} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

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

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

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

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

      \[\leadsto \color{blue}{\frac{x}{1 + x} + \frac{1}{x + -1}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \color{blue}{\frac{1}{x + -1} + \frac{x}{1 + x}} \]
      2. frac-2neg100.0%

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

        \[\leadsto \frac{\color{blue}{-1}}{-\left(x + -1\right)} + \frac{x}{1 + x} \]
      4. clear-num100.0%

        \[\leadsto \frac{-1}{-\left(x + -1\right)} + \color{blue}{\frac{1}{\frac{1 + x}{x}}} \]
      5. frac-add100.0%

        \[\leadsto \color{blue}{\frac{-1 \cdot \frac{1 + x}{x} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}}} \]
      6. fma-def100.0%

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

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(-\color{blue}{\left(-1 + x\right)}\right) \cdot 1\right)}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}} \]
      8. distribute-neg-in100.0%

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

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(\color{blue}{1} + \left(-x\right)\right) \cdot 1\right)}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}} \]
      10. sub-neg100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \color{blue}{\left(1 - x\right)} \cdot 1\right)}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}} \]
      11. +-commutative100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\left(-\color{blue}{\left(-1 + x\right)}\right) \cdot \frac{1 + x}{x}} \]
      12. distribute-neg-in100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\color{blue}{\left(\left(--1\right) + \left(-x\right)\right)} \cdot \frac{1 + x}{x}} \]
      13. metadata-eval100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\left(\color{blue}{1} + \left(-x\right)\right) \cdot \frac{1 + x}{x}} \]
      14. sub-neg100.0%

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

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}}} \]
    7. Step-by-step derivation
      1. fma-udef100.0%

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

        \[\leadsto \frac{\color{blue}{\frac{1 + x}{x} \cdot -1} + \left(1 - x\right) \cdot 1}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      3. *-rgt-identity100.0%

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

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

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

        \[\leadsto \frac{1 - \left(x - \color{blue}{-1 \cdot \frac{1 + x}{x}}\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      7. cancel-sign-sub-inv100.0%

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

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

        \[\leadsto \frac{1 - \left(x + \color{blue}{\frac{1 + x}{x} \cdot 1}\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      10. *-rgt-identity100.0%

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

        \[\leadsto \frac{1 - \left(x + \frac{\color{blue}{x + 1}}{x}\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      12. associate-*r/40.1%

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

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

        \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\frac{1 - x}{\frac{x}{\color{blue}{x + 1}}}} \]
    8. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1 - \left(x + \frac{x + 1}{x}\right)}{\frac{1 - x}{\frac{x}{x + 1}}}} \]
    9. Taylor expanded in x around 0 100.0%

      \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\color{blue}{-1 \cdot x + \frac{1}{x}}} \]
    10. Step-by-step derivation
      1. neg-mul-1100.0%

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

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

        \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\color{blue}{\frac{1}{x} - x}} \]
    11. Simplified100.0%

      \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\color{blue}{\frac{1}{x} - x}} \]
    12. Taylor expanded in x around inf 100.0%

      \[\leadsto \color{blue}{1} \]

    if -1.9199999999999999 < x < 1

    1. Initial program 100.0%

      \[\frac{1}{x - 1} + \frac{x}{x + 1} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

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

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

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

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

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

      \[\leadsto \frac{x}{1 + x} + \color{blue}{\left(-1 \cdot x - 1\right)} \]
    6. Step-by-step derivation
      1. sub-neg98.5%

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

        \[\leadsto \frac{x}{1 + x} + \left(-1 \cdot x + \color{blue}{-1}\right) \]
      3. neg-mul-198.5%

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

        \[\leadsto \frac{x}{1 + x} + \color{blue}{\left(-1 + \left(-x\right)\right)} \]
      5. unsub-neg98.5%

        \[\leadsto \frac{x}{1 + x} + \color{blue}{\left(-1 - x\right)} \]
    7. Simplified98.5%

      \[\leadsto \frac{x}{1 + x} + \color{blue}{\left(-1 - x\right)} \]
    8. Step-by-step derivation
      1. associate-+r-98.5%

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

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

        \[\leadsto \left(-1 + \frac{x}{\color{blue}{x + 1}}\right) - x \]
    9. Applied egg-rr98.5%

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

    if 1 < x

    1. Initial program 100.0%

      \[\frac{1}{x - 1} + \frac{x}{x + 1} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

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

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

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

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

      \[\leadsto \color{blue}{\frac{x}{1 + x} + \frac{1}{x + -1}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 97.8%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.92:\\ \;\;\;\;1\\ \mathbf{elif}\;x \leq 1:\\ \;\;\;\;\left(-1 + \frac{x}{1 + x}\right) - x\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{1 + x} + \frac{1}{x}\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 98.9% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1:\\ \;\;\;\;1\\ \mathbf{elif}\;x \leq 1.9:\\ \;\;\;\;x + \frac{1}{x + -1}\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.0) 1.0 (if (<= x 1.9) (+ x (/ 1.0 (+ x -1.0))) 1.0)))
double code(double x) {
	double tmp;
	if (x <= -1.0) {
		tmp = 1.0;
	} else if (x <= 1.9) {
		tmp = x + (1.0 / (x + -1.0));
	} else {
		tmp = 1.0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1.0d0)) then
        tmp = 1.0d0
    else if (x <= 1.9d0) then
        tmp = x + (1.0d0 / (x + (-1.0d0)))
    else
        tmp = 1.0d0
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -1.0) {
		tmp = 1.0;
	} else if (x <= 1.9) {
		tmp = x + (1.0 / (x + -1.0));
	} else {
		tmp = 1.0;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -1.0:
		tmp = 1.0
	elif x <= 1.9:
		tmp = x + (1.0 / (x + -1.0))
	else:
		tmp = 1.0
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -1.0)
		tmp = 1.0;
	elseif (x <= 1.9)
		tmp = Float64(x + Float64(1.0 / Float64(x + -1.0)));
	else
		tmp = 1.0;
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1.0)
		tmp = 1.0;
	elseif (x <= 1.9)
		tmp = x + (1.0 / (x + -1.0));
	else
		tmp = 1.0;
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -1.0], 1.0, If[LessEqual[x, 1.9], N[(x + N[(1.0 / N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1.0]]
\begin{array}{l}

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

\mathbf{elif}\;x \leq 1.9:\\
\;\;\;\;x + \frac{1}{x + -1}\\

\mathbf{else}:\\
\;\;\;\;1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1 or 1.8999999999999999 < x

    1. Initial program 100.0%

      \[\frac{1}{x - 1} + \frac{x}{x + 1} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

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

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

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

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

      \[\leadsto \color{blue}{\frac{x}{1 + x} + \frac{1}{x + -1}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \color{blue}{\frac{1}{x + -1} + \frac{x}{1 + x}} \]
      2. frac-2neg100.0%

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

        \[\leadsto \frac{\color{blue}{-1}}{-\left(x + -1\right)} + \frac{x}{1 + x} \]
      4. clear-num100.0%

        \[\leadsto \frac{-1}{-\left(x + -1\right)} + \color{blue}{\frac{1}{\frac{1 + x}{x}}} \]
      5. frac-add100.0%

        \[\leadsto \color{blue}{\frac{-1 \cdot \frac{1 + x}{x} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}}} \]
      6. fma-def100.0%

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

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(-\color{blue}{\left(-1 + x\right)}\right) \cdot 1\right)}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}} \]
      8. distribute-neg-in100.0%

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

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(\color{blue}{1} + \left(-x\right)\right) \cdot 1\right)}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}} \]
      10. sub-neg100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \color{blue}{\left(1 - x\right)} \cdot 1\right)}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}} \]
      11. +-commutative100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\left(-\color{blue}{\left(-1 + x\right)}\right) \cdot \frac{1 + x}{x}} \]
      12. distribute-neg-in100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\color{blue}{\left(\left(--1\right) + \left(-x\right)\right)} \cdot \frac{1 + x}{x}} \]
      13. metadata-eval100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\left(\color{blue}{1} + \left(-x\right)\right) \cdot \frac{1 + x}{x}} \]
      14. sub-neg100.0%

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

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}}} \]
    7. Step-by-step derivation
      1. fma-udef100.0%

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

        \[\leadsto \frac{\color{blue}{\frac{1 + x}{x} \cdot -1} + \left(1 - x\right) \cdot 1}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      3. *-rgt-identity100.0%

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

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

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

        \[\leadsto \frac{1 - \left(x - \color{blue}{-1 \cdot \frac{1 + x}{x}}\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      7. cancel-sign-sub-inv100.0%

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

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

        \[\leadsto \frac{1 - \left(x + \color{blue}{\frac{1 + x}{x} \cdot 1}\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      10. *-rgt-identity100.0%

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

        \[\leadsto \frac{1 - \left(x + \frac{\color{blue}{x + 1}}{x}\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      12. associate-*r/44.9%

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

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

        \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\frac{1 - x}{\frac{x}{\color{blue}{x + 1}}}} \]
    8. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1 - \left(x + \frac{x + 1}{x}\right)}{\frac{1 - x}{\frac{x}{x + 1}}}} \]
    9. Taylor expanded in x around 0 100.0%

      \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\color{blue}{-1 \cdot x + \frac{1}{x}}} \]
    10. Step-by-step derivation
      1. neg-mul-1100.0%

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

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

        \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\color{blue}{\frac{1}{x} - x}} \]
    11. Simplified100.0%

      \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\color{blue}{\frac{1}{x} - x}} \]
    12. Taylor expanded in x around inf 98.9%

      \[\leadsto \color{blue}{1} \]

    if -1 < x < 1.8999999999999999

    1. Initial program 100.0%

      \[\frac{1}{x - 1} + \frac{x}{x + 1} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

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

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

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

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

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

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1:\\ \;\;\;\;1\\ \mathbf{elif}\;x \leq 1.9:\\ \;\;\;\;x + \frac{1}{x + -1}\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 98.9% accurate, 1.0× speedup?

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

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

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

\mathbf{else}:\\
\;\;\;\;1\\


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

    1. Initial program 100.0%

      \[\frac{1}{x - 1} + \frac{x}{x + 1} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

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

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

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

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

      \[\leadsto \color{blue}{\frac{x}{1 + x} + \frac{1}{x + -1}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \color{blue}{\frac{1}{x + -1} + \frac{x}{1 + x}} \]
      2. frac-2neg100.0%

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

        \[\leadsto \frac{\color{blue}{-1}}{-\left(x + -1\right)} + \frac{x}{1 + x} \]
      4. clear-num100.0%

        \[\leadsto \frac{-1}{-\left(x + -1\right)} + \color{blue}{\frac{1}{\frac{1 + x}{x}}} \]
      5. frac-add100.0%

        \[\leadsto \color{blue}{\frac{-1 \cdot \frac{1 + x}{x} + \left(-\left(x + -1\right)\right) \cdot 1}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}}} \]
      6. fma-def100.0%

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

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(-\color{blue}{\left(-1 + x\right)}\right) \cdot 1\right)}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}} \]
      8. distribute-neg-in100.0%

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

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(\color{blue}{1} + \left(-x\right)\right) \cdot 1\right)}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}} \]
      10. sub-neg100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \color{blue}{\left(1 - x\right)} \cdot 1\right)}{\left(-\left(x + -1\right)\right) \cdot \frac{1 + x}{x}} \]
      11. +-commutative100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\left(-\color{blue}{\left(-1 + x\right)}\right) \cdot \frac{1 + x}{x}} \]
      12. distribute-neg-in100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\color{blue}{\left(\left(--1\right) + \left(-x\right)\right)} \cdot \frac{1 + x}{x}} \]
      13. metadata-eval100.0%

        \[\leadsto \frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\left(\color{blue}{1} + \left(-x\right)\right) \cdot \frac{1 + x}{x}} \]
      14. sub-neg100.0%

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

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(-1, \frac{1 + x}{x}, \left(1 - x\right) \cdot 1\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}}} \]
    7. Step-by-step derivation
      1. fma-udef100.0%

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

        \[\leadsto \frac{\color{blue}{\frac{1 + x}{x} \cdot -1} + \left(1 - x\right) \cdot 1}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      3. *-rgt-identity100.0%

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

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

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

        \[\leadsto \frac{1 - \left(x - \color{blue}{-1 \cdot \frac{1 + x}{x}}\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      7. cancel-sign-sub-inv100.0%

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

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

        \[\leadsto \frac{1 - \left(x + \color{blue}{\frac{1 + x}{x} \cdot 1}\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      10. *-rgt-identity100.0%

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

        \[\leadsto \frac{1 - \left(x + \frac{\color{blue}{x + 1}}{x}\right)}{\left(1 - x\right) \cdot \frac{1 + x}{x}} \]
      12. associate-*r/44.9%

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

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

        \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\frac{1 - x}{\frac{x}{\color{blue}{x + 1}}}} \]
    8. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1 - \left(x + \frac{x + 1}{x}\right)}{\frac{1 - x}{\frac{x}{x + 1}}}} \]
    9. Taylor expanded in x around 0 100.0%

      \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\color{blue}{-1 \cdot x + \frac{1}{x}}} \]
    10. Step-by-step derivation
      1. neg-mul-1100.0%

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

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

        \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\color{blue}{\frac{1}{x} - x}} \]
    11. Simplified100.0%

      \[\leadsto \frac{1 - \left(x + \frac{x + 1}{x}\right)}{\color{blue}{\frac{1}{x} - x}} \]
    12. Taylor expanded in x around inf 98.9%

      \[\leadsto \color{blue}{1} \]

    if -1 < x < 1

    1. Initial program 100.0%

      \[\frac{1}{x - 1} + \frac{x}{x + 1} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

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

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

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

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

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

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

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

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

Alternative 7: 50.1% accurate, 11.0× 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 100.0%

    \[\frac{1}{x - 1} + \frac{x}{x + 1} \]
  2. Step-by-step derivation
    1. +-commutative100.0%

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

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

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

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

    \[\leadsto \color{blue}{\frac{x}{1 + x} + \frac{1}{x + -1}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 49.4%

    \[\leadsto \color{blue}{x} + \frac{1}{x + -1} \]
  6. Taylor expanded in x around 0 48.5%

    \[\leadsto \color{blue}{-1} \]
  7. Final simplification48.5%

    \[\leadsto -1 \]
  8. Add Preprocessing

Reproduce

?
herbie shell --seed 2024027 
(FPCore (x)
  :name "Asymptote B"
  :precision binary64
  (+ (/ 1.0 (- x 1.0)) (/ x (+ x 1.0))))