Asymptote C

Percentage Accurate: 54.6% → 100.0%
Time: 9.6s
Alternatives: 8
Speedup: 1.2×

Specification

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

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

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 8 alternatives:

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

Initial Program: 54.6% 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: 100.0% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \frac{-3 + \frac{-1}{x}}{\left(-1 + \frac{-1}{x}\right) + \left(x + 1\right)} \end{array} \]
(FPCore (x)
 :precision binary64
 (/ (+ -3.0 (/ -1.0 x)) (+ (+ -1.0 (/ -1.0 x)) (+ x 1.0))))
double code(double x) {
	return (-3.0 + (-1.0 / x)) / ((-1.0 + (-1.0 / x)) + (x + 1.0));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = ((-3.0d0) + ((-1.0d0) / x)) / (((-1.0d0) + ((-1.0d0) / x)) + (x + 1.0d0))
end function
public static double code(double x) {
	return (-3.0 + (-1.0 / x)) / ((-1.0 + (-1.0 / x)) + (x + 1.0));
}
def code(x):
	return (-3.0 + (-1.0 / x)) / ((-1.0 + (-1.0 / x)) + (x + 1.0))
function code(x)
	return Float64(Float64(-3.0 + Float64(-1.0 / x)) / Float64(Float64(-1.0 + Float64(-1.0 / x)) + Float64(x + 1.0)))
end
function tmp = code(x)
	tmp = (-3.0 + (-1.0 / x)) / ((-1.0 + (-1.0 / x)) + (x + 1.0));
end
code[x_] := N[(N[(-3.0 + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision] / N[(N[(-1.0 + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision] + N[(x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-3 + \frac{-1}{x}}{\left(-1 + \frac{-1}{x}\right) + \left(x + 1\right)}
\end{array}
Derivation
  1. Initial program 52.9%

    \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
  2. Step-by-step derivation
    1. remove-double-neg52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
    2. distribute-neg-in52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
    3. sub-neg52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
    4. distribute-frac-neg52.9%

      \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
    5. distribute-frac-neg252.9%

      \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
    6. sub-neg52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
    7. +-commutative52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
    8. unsub-neg52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
    9. metadata-eval52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
    10. neg-sub052.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
    11. associate-+l-52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
    12. neg-sub052.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
    13. +-commutative52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
    14. unsub-neg52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
  3. Simplified52.9%

    \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. clear-num52.9%

      \[\leadsto \color{blue}{\frac{1}{\frac{x + 1}{x}}} - \frac{-1 - x}{1 - x} \]
    2. frac-sub54.3%

      \[\leadsto \color{blue}{\frac{1 \cdot \left(1 - x\right) - \frac{x + 1}{x} \cdot \left(-1 - x\right)}{\frac{x + 1}{x} \cdot \left(1 - x\right)}} \]
    3. *-un-lft-identity54.3%

      \[\leadsto \frac{\color{blue}{\left(1 - x\right)} - \frac{x + 1}{x} \cdot \left(-1 - x\right)}{\frac{x + 1}{x} \cdot \left(1 - x\right)} \]
  6. Applied egg-rr54.3%

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

    \[\leadsto \frac{\color{blue}{3 + \frac{1}{x}}}{\frac{x + 1}{x} \cdot \left(1 - x\right)} \]
  8. Step-by-step derivation
    1. +-commutative100.0%

      \[\leadsto \frac{\color{blue}{\frac{1}{x} + 3}}{\frac{x + 1}{x} \cdot \left(1 - x\right)} \]
  9. Simplified100.0%

    \[\leadsto \frac{\color{blue}{\frac{1}{x} + 3}}{\frac{x + 1}{x} \cdot \left(1 - x\right)} \]
  10. Step-by-step derivation
    1. *-un-lft-identity100.0%

      \[\leadsto \color{blue}{1 \cdot \frac{\frac{1}{x} + 3}{\frac{x + 1}{x} \cdot \left(1 - x\right)}} \]
    2. +-commutative100.0%

      \[\leadsto 1 \cdot \frac{\frac{1}{x} + 3}{\frac{\color{blue}{1 + x}}{x} \cdot \left(1 - x\right)} \]
  11. Applied egg-rr100.0%

    \[\leadsto \color{blue}{1 \cdot \frac{\frac{1}{x} + 3}{\frac{1 + x}{x} \cdot \left(1 - x\right)}} \]
  12. Step-by-step derivation
    1. *-lft-identity100.0%

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

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

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

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

      \[\leadsto \frac{\frac{1}{x} + 3}{\color{blue}{-\frac{1 + x}{x} \cdot \left(-1 + x\right)}} \]
    6. distribute-neg-frac2100.0%

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

      \[\leadsto \color{blue}{\frac{-\left(\frac{1}{x} + 3\right)}{\frac{1 + x}{x} \cdot \left(-1 + x\right)}} \]
    8. +-commutative100.0%

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

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

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

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

      \[\leadsto \frac{-3 + \frac{\color{blue}{-1}}{x}}{\frac{1 + x}{x} \cdot \left(-1 + x\right)} \]
    13. +-commutative100.0%

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

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

      \[\leadsto \frac{-3 + \frac{-1}{x}}{\frac{\color{blue}{\left(1 + x\right) \cdot 1}}{x} \cdot x + \frac{1 + x}{x} \cdot -1} \]
    16. associate-*r/99.8%

      \[\leadsto \frac{-3 + \frac{-1}{x}}{\color{blue}{\left(\left(1 + x\right) \cdot \frac{1}{x}\right)} \cdot x + \frac{1 + x}{x} \cdot -1} \]
    17. associate-*l*99.8%

      \[\leadsto \frac{-3 + \frac{-1}{x}}{\color{blue}{\left(1 + x\right) \cdot \left(\frac{1}{x} \cdot x\right)} + \frac{1 + x}{x} \cdot -1} \]
    18. lft-mult-inverse100.0%

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

      \[\leadsto \frac{-3 + \frac{-1}{x}}{\color{blue}{\left(1 + x\right)} + \frac{1 + x}{x} \cdot -1} \]
    20. *-commutative100.0%

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

      \[\leadsto \frac{-3 + \frac{-1}{x}}{\left(1 + x\right) + -1 \cdot \color{blue}{\left(1 \cdot \frac{1 + x}{x}\right)}} \]
  13. Simplified100.0%

    \[\leadsto \color{blue}{\frac{-3 + \frac{-1}{x}}{\left(1 + x\right) + \left(\frac{-1}{x} + -1\right)}} \]
  14. Final simplification100.0%

    \[\leadsto \frac{-3 + \frac{-1}{x}}{\left(-1 + \frac{-1}{x}\right) + \left(x + 1\right)} \]
  15. Add Preprocessing

Alternative 2: 98.9% accurate, 0.7× speedup?

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

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

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


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

    1. Initial program 10.1%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. remove-double-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
      2. distribute-neg-in10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
      3. sub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
      4. distribute-frac-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
      5. distribute-frac-neg210.1%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
      6. sub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
      7. +-commutative10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
      8. unsub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
      9. metadata-eval10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
      10. neg-sub010.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
      11. associate-+l-10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
      12. neg-sub010.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
      13. +-commutative10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
      14. unsub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
    3. Simplified10.1%

      \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 98.0%

      \[\leadsto \color{blue}{-1 \cdot \frac{3 + \frac{1}{x}}{x}} \]
    6. Step-by-step derivation
      1. associate-*r/98.0%

        \[\leadsto \color{blue}{\frac{-1 \cdot \left(3 + \frac{1}{x}\right)}{x}} \]
      2. neg-mul-198.0%

        \[\leadsto \frac{\color{blue}{-\left(3 + \frac{1}{x}\right)}}{x} \]
      3. distribute-neg-in98.0%

        \[\leadsto \frac{\color{blue}{\left(-3\right) + \left(-\frac{1}{x}\right)}}{x} \]
      4. metadata-eval98.0%

        \[\leadsto \frac{\color{blue}{-3} + \left(-\frac{1}{x}\right)}{x} \]
      5. unsub-neg98.0%

        \[\leadsto \frac{\color{blue}{-3 - \frac{1}{x}}}{x} \]
    7. Simplified98.0%

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

    if -1 < x < 1.69999999999999996

    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 99.4%

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

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

Alternative 3: 98.7% 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 10.1%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. remove-double-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
      2. distribute-neg-in10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
      3. sub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
      4. distribute-frac-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
      5. distribute-frac-neg210.1%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
      6. sub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
      7. +-commutative10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
      8. unsub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
      9. metadata-eval10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
      10. neg-sub010.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
      11. associate-+l-10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
      12. neg-sub010.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
      13. +-commutative10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
      14. unsub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
    3. Simplified10.1%

      \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 97.0%

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

    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 99.3%

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

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

Alternative 4: 99.1% accurate, 0.8× speedup?

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

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

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


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

    1. Initial program 10.1%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. remove-double-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
      2. distribute-neg-in10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
      3. sub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
      4. distribute-frac-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
      5. distribute-frac-neg210.1%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
      6. sub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
      7. +-commutative10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
      8. unsub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
      9. metadata-eval10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
      10. neg-sub010.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
      11. associate-+l-10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
      12. neg-sub010.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
      13. +-commutative10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
      14. unsub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
    3. Simplified10.1%

      \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 98.0%

      \[\leadsto \color{blue}{-1 \cdot \frac{3 + \frac{1}{x}}{x}} \]
    6. Step-by-step derivation
      1. associate-*r/98.0%

        \[\leadsto \color{blue}{\frac{-1 \cdot \left(3 + \frac{1}{x}\right)}{x}} \]
      2. neg-mul-198.0%

        \[\leadsto \frac{\color{blue}{-\left(3 + \frac{1}{x}\right)}}{x} \]
      3. distribute-neg-in98.0%

        \[\leadsto \frac{\color{blue}{\left(-3\right) + \left(-\frac{1}{x}\right)}}{x} \]
      4. metadata-eval98.0%

        \[\leadsto \frac{\color{blue}{-3} + \left(-\frac{1}{x}\right)}{x} \]
      5. unsub-neg98.0%

        \[\leadsto \frac{\color{blue}{-3 - \frac{1}{x}}}{x} \]
    7. Simplified98.0%

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

    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 99.3%

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

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

Alternative 5: 98.6% 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 10.1%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. remove-double-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
      2. distribute-neg-in10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
      3. sub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
      4. distribute-frac-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
      5. distribute-frac-neg210.1%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
      6. sub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
      7. +-commutative10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
      8. unsub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
      9. metadata-eval10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
      10. neg-sub010.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
      11. associate-+l-10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
      12. neg-sub010.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
      13. +-commutative10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
      14. unsub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
    3. Simplified10.1%

      \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 97.0%

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

    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 99.3%

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

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

Alternative 6: 98.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\ \;\;\;\;\frac{-3}{x}\\ \mathbf{else}:\\ \;\;\;\;x + 1\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (or (<= x -1.0) (not (<= x 1.0))) (/ -3.0 x) (+ x 1.0)))
double code(double x) {
	double tmp;
	if ((x <= -1.0) || !(x <= 1.0)) {
		tmp = -3.0 / x;
	} else {
		tmp = 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) / x
    else
        tmp = 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 / x;
	} else {
		tmp = x + 1.0;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if (x <= -1.0) or not (x <= 1.0):
		tmp = -3.0 / x
	else:
		tmp = x + 1.0
	return tmp
function code(x)
	tmp = 0.0
	if ((x <= -1.0) || !(x <= 1.0))
		tmp = Float64(-3.0 / x);
	else
		tmp = 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 / x;
	else
		tmp = x + 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], N[(x + 1.0), $MachinePrecision]]
\begin{array}{l}

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

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


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

    1. Initial program 10.1%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Step-by-step derivation
      1. remove-double-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
      2. distribute-neg-in10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
      3. sub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
      4. distribute-frac-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
      5. distribute-frac-neg210.1%

        \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
      6. sub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
      7. +-commutative10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
      8. unsub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
      9. metadata-eval10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
      10. neg-sub010.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
      11. associate-+l-10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
      12. neg-sub010.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
      13. +-commutative10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
      14. unsub-neg10.1%

        \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
    3. Simplified10.1%

      \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 97.0%

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

    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 99.4%

      \[\leadsto \color{blue}{x} - \frac{-1 - x}{1 - x} \]
    6. Taylor expanded in x around 0 98.9%

      \[\leadsto x - \color{blue}{-1} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification97.9%

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

Alternative 7: 100.0% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \frac{-3 + \frac{-1}{x}}{x + \frac{-1}{x}} \end{array} \]
(FPCore (x) :precision binary64 (/ (+ -3.0 (/ -1.0 x)) (+ x (/ -1.0 x))))
double code(double x) {
	return (-3.0 + (-1.0 / x)) / (x + (-1.0 / x));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = ((-3.0d0) + ((-1.0d0) / x)) / (x + ((-1.0d0) / x))
end function
public static double code(double x) {
	return (-3.0 + (-1.0 / x)) / (x + (-1.0 / x));
}
def code(x):
	return (-3.0 + (-1.0 / x)) / (x + (-1.0 / x))
function code(x)
	return Float64(Float64(-3.0 + Float64(-1.0 / x)) / Float64(x + Float64(-1.0 / x)))
end
function tmp = code(x)
	tmp = (-3.0 + (-1.0 / x)) / (x + (-1.0 / x));
end
code[x_] := N[(N[(-3.0 + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision] / N[(x + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-3 + \frac{-1}{x}}{x + \frac{-1}{x}}
\end{array}
Derivation
  1. Initial program 52.9%

    \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
  2. Step-by-step derivation
    1. remove-double-neg52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
    2. distribute-neg-in52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
    3. sub-neg52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
    4. distribute-frac-neg52.9%

      \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
    5. distribute-frac-neg252.9%

      \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
    6. sub-neg52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
    7. +-commutative52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
    8. unsub-neg52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
    9. metadata-eval52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
    10. neg-sub052.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
    11. associate-+l-52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
    12. neg-sub052.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
    13. +-commutative52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
    14. unsub-neg52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
  3. Simplified52.9%

    \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. clear-num52.9%

      \[\leadsto \color{blue}{\frac{1}{\frac{x + 1}{x}}} - \frac{-1 - x}{1 - x} \]
    2. frac-sub54.3%

      \[\leadsto \color{blue}{\frac{1 \cdot \left(1 - x\right) - \frac{x + 1}{x} \cdot \left(-1 - x\right)}{\frac{x + 1}{x} \cdot \left(1 - x\right)}} \]
    3. *-un-lft-identity54.3%

      \[\leadsto \frac{\color{blue}{\left(1 - x\right)} - \frac{x + 1}{x} \cdot \left(-1 - x\right)}{\frac{x + 1}{x} \cdot \left(1 - x\right)} \]
  6. Applied egg-rr54.3%

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

    \[\leadsto \frac{\color{blue}{3 + \frac{1}{x}}}{\frac{x + 1}{x} \cdot \left(1 - x\right)} \]
  8. Step-by-step derivation
    1. +-commutative100.0%

      \[\leadsto \frac{\color{blue}{\frac{1}{x} + 3}}{\frac{x + 1}{x} \cdot \left(1 - x\right)} \]
  9. Simplified100.0%

    \[\leadsto \frac{\color{blue}{\frac{1}{x} + 3}}{\frac{x + 1}{x} \cdot \left(1 - x\right)} \]
  10. Step-by-step derivation
    1. *-un-lft-identity100.0%

      \[\leadsto \color{blue}{1 \cdot \frac{\frac{1}{x} + 3}{\frac{x + 1}{x} \cdot \left(1 - x\right)}} \]
    2. +-commutative100.0%

      \[\leadsto 1 \cdot \frac{\frac{1}{x} + 3}{\frac{\color{blue}{1 + x}}{x} \cdot \left(1 - x\right)} \]
  11. Applied egg-rr100.0%

    \[\leadsto \color{blue}{1 \cdot \frac{\frac{1}{x} + 3}{\frac{1 + x}{x} \cdot \left(1 - x\right)}} \]
  12. Step-by-step derivation
    1. *-lft-identity100.0%

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

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

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

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

      \[\leadsto \frac{\frac{1}{x} + 3}{\color{blue}{-\frac{1 + x}{x} \cdot \left(-1 + x\right)}} \]
    6. distribute-neg-frac2100.0%

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

      \[\leadsto \color{blue}{\frac{-\left(\frac{1}{x} + 3\right)}{\frac{1 + x}{x} \cdot \left(-1 + x\right)}} \]
    8. +-commutative100.0%

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

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

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

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

      \[\leadsto \frac{-3 + \frac{\color{blue}{-1}}{x}}{\frac{1 + x}{x} \cdot \left(-1 + x\right)} \]
    13. +-commutative100.0%

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

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

      \[\leadsto \frac{-3 + \frac{-1}{x}}{\frac{\color{blue}{\left(1 + x\right) \cdot 1}}{x} \cdot x + \frac{1 + x}{x} \cdot -1} \]
    16. associate-*r/99.8%

      \[\leadsto \frac{-3 + \frac{-1}{x}}{\color{blue}{\left(\left(1 + x\right) \cdot \frac{1}{x}\right)} \cdot x + \frac{1 + x}{x} \cdot -1} \]
    17. associate-*l*99.8%

      \[\leadsto \frac{-3 + \frac{-1}{x}}{\color{blue}{\left(1 + x\right) \cdot \left(\frac{1}{x} \cdot x\right)} + \frac{1 + x}{x} \cdot -1} \]
    18. lft-mult-inverse100.0%

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

      \[\leadsto \frac{-3 + \frac{-1}{x}}{\color{blue}{\left(1 + x\right)} + \frac{1 + x}{x} \cdot -1} \]
    20. *-commutative100.0%

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

      \[\leadsto \frac{-3 + \frac{-1}{x}}{\left(1 + x\right) + -1 \cdot \color{blue}{\left(1 \cdot \frac{1 + x}{x}\right)}} \]
  13. Simplified100.0%

    \[\leadsto \color{blue}{\frac{-3 + \frac{-1}{x}}{\left(1 + x\right) + \left(\frac{-1}{x} + -1\right)}} \]
  14. Taylor expanded in x around 0 78.0%

    \[\leadsto \frac{-3 + \frac{-1}{x}}{\color{blue}{\frac{{x}^{2} - 1}{x}}} \]
  15. Step-by-step derivation
    1. div-sub78.0%

      \[\leadsto \frac{-3 + \frac{-1}{x}}{\color{blue}{\frac{{x}^{2}}{x} - \frac{1}{x}}} \]
    2. sub-neg78.0%

      \[\leadsto \frac{-3 + \frac{-1}{x}}{\color{blue}{\frac{{x}^{2}}{x} + \left(-\frac{1}{x}\right)}} \]
    3. unpow278.0%

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

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

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

      \[\leadsto \frac{-3 + \frac{-1}{x}}{x \cdot \color{blue}{\left(x \cdot \frac{1}{x}\right)} + \left(-\frac{1}{x}\right)} \]
    7. rgt-mult-inverse100.0%

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

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

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

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

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

    \[\leadsto \frac{-3 + \frac{-1}{x}}{\color{blue}{x + \frac{-1}{x}}} \]
  17. Final simplification100.0%

    \[\leadsto \frac{-3 + \frac{-1}{x}}{x + \frac{-1}{x}} \]
  18. Add Preprocessing

Alternative 8: 51.2% 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 52.9%

    \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
  2. Step-by-step derivation
    1. remove-double-neg52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-\left(-\left(x + 1\right)\right)}}{x - 1} \]
    2. distribute-neg-in52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) + \left(-1\right)\right)}}{x - 1} \]
    3. sub-neg52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-\color{blue}{\left(\left(-x\right) - 1\right)}}{x - 1} \]
    4. distribute-frac-neg52.9%

      \[\leadsto \frac{x}{x + 1} - \color{blue}{\left(-\frac{\left(-x\right) - 1}{x - 1}\right)} \]
    5. distribute-frac-neg252.9%

      \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{\left(-x\right) - 1}{-\left(x - 1\right)}} \]
    6. sub-neg52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-x\right) + \left(-1\right)}}{-\left(x - 1\right)} \]
    7. +-commutative52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) + \left(-x\right)}}{-\left(x - 1\right)} \]
    8. unsub-neg52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{\left(-1\right) - x}}{-\left(x - 1\right)} \]
    9. metadata-eval52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{\color{blue}{-1} - x}{-\left(x - 1\right)} \]
    10. neg-sub052.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{0 - \left(x - 1\right)}} \]
    11. associate-+l-52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(0 - x\right) + 1}} \]
    12. neg-sub052.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{\left(-x\right)} + 1} \]
    13. +-commutative52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 + \left(-x\right)}} \]
    14. unsub-neg52.9%

      \[\leadsto \frac{x}{x + 1} - \frac{-1 - x}{\color{blue}{1 - x}} \]
  3. Simplified52.9%

    \[\leadsto \color{blue}{\frac{x}{x + 1} - \frac{-1 - x}{1 - x}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 49.3%

    \[\leadsto \color{blue}{1} \]
  6. Final simplification49.3%

    \[\leadsto 1 \]
  7. Add Preprocessing

Reproduce

?
herbie shell --seed 2024100 
(FPCore (x)
  :name "Asymptote C"
  :precision binary64
  (- (/ x (+ x 1.0)) (/ (+ x 1.0) (- x 1.0))))