Asymptote A

Percentage Accurate: 77.6% → 99.4%

Time: 5.5s

Alternatives: 8

Speedup: 1.2×

Specification

Math

\[\begin{array}{l} \\ \frac{1}{x + 1} - \frac{1}{x - 1} \end{array} \]

FPCore

(FPCore (x) :precision binary64 (- (/ 1.0 (+ x 1.0)) (/ 1.0 (- x 1.0))))

C

double code(double x) {
	return (1.0 / (x + 1.0)) - (1.0 / (x - 1.0));
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    code = (1.0d0 / (x + 1.0d0)) - (1.0d0 / (x - 1.0d0))
end function

Java

public static double code(double x) {
	return (1.0 / (x + 1.0)) - (1.0 / (x - 1.0));
}

Python

def code(x):
	return (1.0 / (x + 1.0)) - (1.0 / (x - 1.0))

Julia

function code(x)
	return Float64(Float64(1.0 / Float64(x + 1.0)) - Float64(1.0 / Float64(x - 1.0)))
end

MATLAB

function tmp = code(x)
	tmp = (1.0 / (x + 1.0)) - (1.0 / (x - 1.0));
end

Wolfram

code[x_] := N[(N[(1.0 / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] - N[(1.0 / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]

Initial Program: 77.6% accurate, 1.0× speedup

Math

\[\begin{array}{l} \\ \frac{1}{x + 1} - \frac{1}{x - 1} \end{array} \]

FPCore

(FPCore (x) :precision binary64 (- (/ 1.0 (+ x 1.0)) (/ 1.0 (- x 1.0))))

C

double code(double x) {
	return (1.0 / (x + 1.0)) - (1.0 / (x - 1.0));
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    code = (1.0d0 / (x + 1.0d0)) - (1.0d0 / (x - 1.0d0))
end function

Java

public static double code(double x) {
	return (1.0 / (x + 1.0)) - (1.0 / (x - 1.0));
}

Python

def code(x):
	return (1.0 / (x + 1.0)) - (1.0 / (x - 1.0))

Julia

function code(x)
	return Float64(Float64(1.0 / Float64(x + 1.0)) - Float64(1.0 / Float64(x - 1.0)))
end

MATLAB

function tmp = code(x)
	tmp = (1.0 / (x + 1.0)) - (1.0 / (x - 1.0));
end

Wolfram

code[x_] := N[(N[(1.0 / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] - N[(1.0 / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]

Alternative 1: 99.4% accurate, 1.0× speedup

Math

\[\begin{array}{l} \\ \frac{2}{\left(1 + x\right) + x \cdot \left(-1 - x\right)} \end{array} \]

FPCore

(FPCore (x) :precision binary64 (/ 2.0 (+ (+ 1.0 x) (* x (- -1.0 x)))))

C

double code(double x) {
	return 2.0 / ((1.0 + x) + (x * (-1.0 - x)));
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    code = 2.0d0 / ((1.0d0 + x) + (x * ((-1.0d0) - x)))
end function

Java

public static double code(double x) {
	return 2.0 / ((1.0 + x) + (x * (-1.0 - x)));
}

Python

def code(x):
	return 2.0 / ((1.0 + x) + (x * (-1.0 - x)))

Julia

function code(x)
	return Float64(2.0 / Float64(Float64(1.0 + x) + Float64(x * Float64(-1.0 - x))))
end

MATLAB

function tmp = code(x)
	tmp = 2.0 / ((1.0 + x) + (x * (-1.0 - x)));
end

Wolfram

code[x_] := N[(2.0 / N[(N[(1.0 + x), $MachinePrecision] + N[(x * N[(-1.0 - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]

Derivation

1. Initial program 80.2%

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

   1. sub-neg 80.2%

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

   2. +-commutative 80.2%

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

   3. distribute-neg-frac 80.2%

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

   4. metadata-eval 80.2%

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

   5. metadata-eval 80.2%

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

   6. metadata-eval 80.2%

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

   7. associate-/r* 80.2%

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

   8. metadata-eval 80.2%

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

   9. neg-mul-1 80.2%

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

   10. sub0-neg 80.2%

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

   11. associate-+l- 80.2%

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

   12. neg-sub0 80.2%

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

   13. remove-double-neg 80.2%

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

   14. distribute-neg-in 80.2%

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

   15. sub-neg 80.2%

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

   16. mul-1-neg 80.2%

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

   17. metadata-eval 80.2%

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

   18. associate-/r* 80.2%

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

   19. metadata-eval 80.2%

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

   20. metadata-eval 80.2%

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

   21. metadata-eval 80.2%

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

   22. metadata-eval 80.2%

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

   23. associate-*l/ 80.2%

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

3. Simplified 80.2%

   \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
4. Step-by-step derivation

   1. sub-neg 80.2%

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

   2. distribute-neg-frac 80.2%

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

   3. metadata-eval 80.2%

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

5. Applied egg-rr 80.2%

   \[\leadsto \color{blue}{\frac{1}{1 - x} + \frac{-1}{-1 - x}} \]
6. Step-by-step derivation

   1. *-rgt-identity 80.2%

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

   2. cancel-sign-sub 80.2%

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

   3. distribute-neg-frac 80.2%

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

   4. metadata-eval 80.2%

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

   5. *-rgt-identity 80.2%

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

   6. *-inverses 80.2%

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

   7. associate-/r* 53.7%

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

   8. distribute-lft-neg-in 53.7%

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

   9. distribute-rgt-neg-in 53.7%

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

   10. *-commutative 53.7%

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

   11. *-lft-identity 53.7%

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

   12. *-inverses 53.7%

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

   13. times-frac 80.2%

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

   14. div-sub 81.2%

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

7. Simplified 99.5%

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

   1. +-commutative 99.5%

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

   2. distribute-rgt-in 99.5%

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

   3. sub-neg 99.5%

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

   4. distribute-rgt-in 99.5%

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

   5. metadata-eval 99.5%

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

   6. cancel-sign-sub-inv 99.5%

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

   7. *-commutative 99.5%

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

   8. neg-mul-1 99.5%

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

9. Applied egg-rr 99.5%

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

10. Final simplification 99.5%

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

Alternative 2: 73.9% accurate, 1.2× speedup

Math

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

FPCore

(FPCore (x) :precision binary64 (if (<= x 1.0) 2.0 (/ 2.0 (* x (- -1.0 x)))))

C

double code(double x) {
	double tmp;
	if (x <= 1.0) {
		tmp = 2.0;
	} else {
		tmp = 2.0 / (x * (-1.0 - x));
	}
	return tmp;
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 1.0d0) then
        tmp = 2.0d0
    else
        tmp = 2.0d0 / (x * ((-1.0d0) - x))
    end if
    code = tmp
end function

Java

public static double code(double x) {
	double tmp;
	if (x <= 1.0) {
		tmp = 2.0;
	} else {
		tmp = 2.0 / (x * (-1.0 - x));
	}
	return tmp;
}

Python

def code(x):
	tmp = 0
	if x <= 1.0:
		tmp = 2.0
	else:
		tmp = 2.0 / (x * (-1.0 - x))
	return tmp

Julia

function code(x)
	tmp = 0.0
	if (x <= 1.0)
		tmp = 2.0;
	else
		tmp = Float64(2.0 / Float64(x * Float64(-1.0 - x)));
	end
	return tmp
end

MATLAB

function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 1.0)
		tmp = 2.0;
	else
		tmp = 2.0 / (x * (-1.0 - x));
	end
	tmp_2 = tmp;
end

Wolfram

code[x_] := If[LessEqual[x, 1.0], 2.0, N[(2.0 / N[(x * N[(-1.0 - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]

Derivation

1. Split input into 2 regimes

2. if x < 1

   1. Initial program 84.5%

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

      1. sub-neg 84.5%

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

      2. +-commutative 84.5%

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

      3. distribute-neg-frac 84.5%

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

      4. metadata-eval 84.5%

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

      5. metadata-eval 84.5%

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

      6. metadata-eval 84.5%

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

      7. associate-/r* 84.5%

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

      8. metadata-eval 84.5%

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

      9. neg-mul-1 84.5%

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

      10. sub0-neg 84.5%

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

      11. associate-+l- 84.5%

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

      12. neg-sub0 84.5%

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

      13. remove-double-neg 84.5%

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

      14. distribute-neg-in 84.5%

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

      15. sub-neg 84.5%

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

      16. mul-1-neg 84.5%

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

      17. metadata-eval 84.5%

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

      18. associate-/r* 84.5%

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

      19. metadata-eval 84.5%

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

      20. metadata-eval 84.5%

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

      21. metadata-eval 84.5%

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

      22. metadata-eval 84.5%

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

      23. associate-*l/ 84.5%

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

   3. Simplified 84.5%

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

   4. Taylor expanded in x around 0 66.6%

      \[\leadsto \color{blue}{2} \]

   if 1 < x

   1. Initial program 68.3%

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

      1. sub-neg 68.3%

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

      2. +-commutative 68.3%

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

      3. distribute-neg-frac 68.3%

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

      4. metadata-eval 68.3%

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

      5. metadata-eval 68.3%

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

      6. metadata-eval 68.3%

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

      7. associate-/r* 68.3%

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

      8. metadata-eval 68.3%

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

      9. neg-mul-1 68.3%

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

      10. sub0-neg 68.3%

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

      11. associate-+l- 68.3%

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

      12. neg-sub0 68.3%

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

      13. remove-double-neg 68.3%

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

      14. distribute-neg-in 68.3%

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

      15. sub-neg 68.3%

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

      16. mul-1-neg 68.3%

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

      17. metadata-eval 68.3%

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

      18. associate-/r* 68.3%

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

      19. metadata-eval 68.3%

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

      20. metadata-eval 68.3%

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

      21. metadata-eval 68.3%

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

      22. metadata-eval 68.3%

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

      23. associate-*l/ 68.3%

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

   3. Simplified 68.3%

      \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
   4. Step-by-step derivation

      1. frac-sub 71.7%

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

      2. *-rgt-identity 71.7%

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

      3. metadata-eval 71.7%

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

      4. div-inv 71.7%

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

      5. associate-/r* 71.7%

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

      6. *-un-lft-identity 71.7%

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

      7. metadata-eval 71.7%

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

      8. div-inv 71.7%

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

      9. associate--l- 75.7%

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

      10. div-inv 75.7%

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

      11. metadata-eval 75.7%

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

      12. *-rgt-identity 75.7%

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

      13. div-inv 75.7%

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

      14. metadata-eval 75.7%

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

      15. *-rgt-identity 75.7%

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

   5. Applied egg-rr 75.7%

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

   6. Taylor expanded in x around inf 96.4%

      \[\leadsto \frac{\color{blue}{\frac{2}{x}}}{-1 - x} \]
   7. Step-by-step derivation

      1. expm1-log1p-u 96.4%

         \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{\frac{2}{x}}{-1 - x}\right)\right)} \]

      2. expm1-udef 64.7%

         \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\frac{\frac{2}{x}}{-1 - x}\right)} - 1} \]

      3. associate-/l/ 64.7%

         \[\leadsto e^{\mathsf{log1p}\left(\color{blue}{\frac{2}{\left(-1 - x\right) \cdot x}}\right)} - 1 \]

      4. *-commutative 64.7%

         \[\leadsto e^{\mathsf{log1p}\left(\frac{2}{\color{blue}{x \cdot \left(-1 - x\right)}}\right)} - 1 \]

   8. Applied egg-rr 64.7%

      \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\frac{2}{x \cdot \left(-1 - x\right)}\right)} - 1} \]
   9. Step-by-step derivation

      1. expm1-def 96.3%

         \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{2}{x \cdot \left(-1 - x\right)}\right)\right)} \]

      2. expm1-log1p 96.3%

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

   10. Simplified 96.3%

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

4. Final simplification 74.4%

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

Alternative 3: 74.1% accurate, 1.2× speedup

Math

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;2\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{2}{x}}{-1 - x}\\ \end{array} \end{array} \]

FPCore

(FPCore (x) :precision binary64 (if (<= x 1.0) 2.0 (/ (/ 2.0 x) (- -1.0 x))))

C

double code(double x) {
	double tmp;
	if (x <= 1.0) {
		tmp = 2.0;
	} else {
		tmp = (2.0 / x) / (-1.0 - x);
	}
	return tmp;
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 1.0d0) then
        tmp = 2.0d0
    else
        tmp = (2.0d0 / x) / ((-1.0d0) - x)
    end if
    code = tmp
end function

Java

public static double code(double x) {
	double tmp;
	if (x <= 1.0) {
		tmp = 2.0;
	} else {
		tmp = (2.0 / x) / (-1.0 - x);
	}
	return tmp;
}

Python

def code(x):
	tmp = 0
	if x <= 1.0:
		tmp = 2.0
	else:
		tmp = (2.0 / x) / (-1.0 - x)
	return tmp

Julia

function code(x)
	tmp = 0.0
	if (x <= 1.0)
		tmp = 2.0;
	else
		tmp = Float64(Float64(2.0 / x) / Float64(-1.0 - x));
	end
	return tmp
end

MATLAB

function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 1.0)
		tmp = 2.0;
	else
		tmp = (2.0 / x) / (-1.0 - x);
	end
	tmp_2 = tmp;
end

Wolfram

code[x_] := If[LessEqual[x, 1.0], 2.0, N[(N[(2.0 / x), $MachinePrecision] / N[(-1.0 - x), $MachinePrecision]), $MachinePrecision]]

Derivation

1. Split input into 2 regimes

2. if x < 1

   1. Initial program 84.5%

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

      1. sub-neg 84.5%

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

      2. +-commutative 84.5%

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

      3. distribute-neg-frac 84.5%

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

      4. metadata-eval 84.5%

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

      5. metadata-eval 84.5%

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

      6. metadata-eval 84.5%

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

      7. associate-/r* 84.5%

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

      8. metadata-eval 84.5%

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

      9. neg-mul-1 84.5%

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

      10. sub0-neg 84.5%

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

      11. associate-+l- 84.5%

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

      12. neg-sub0 84.5%

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

      13. remove-double-neg 84.5%

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

      14. distribute-neg-in 84.5%

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

      15. sub-neg 84.5%

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

      16. mul-1-neg 84.5%

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

      17. metadata-eval 84.5%

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

      18. associate-/r* 84.5%

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

      19. metadata-eval 84.5%

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

      20. metadata-eval 84.5%

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

      21. metadata-eval 84.5%

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

      22. metadata-eval 84.5%

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

      23. associate-*l/ 84.5%

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

   3. Simplified 84.5%

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

   4. Taylor expanded in x around 0 66.6%

      \[\leadsto \color{blue}{2} \]

   if 1 < x

   1. Initial program 68.3%

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

      1. sub-neg 68.3%

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

      2. +-commutative 68.3%

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

      3. distribute-neg-frac 68.3%

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

      4. metadata-eval 68.3%

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

      5. metadata-eval 68.3%

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

      6. metadata-eval 68.3%

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

      7. associate-/r* 68.3%

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

      8. metadata-eval 68.3%

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

      9. neg-mul-1 68.3%

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

      10. sub0-neg 68.3%

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

      11. associate-+l- 68.3%

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

      12. neg-sub0 68.3%

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

      13. remove-double-neg 68.3%

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

      14. distribute-neg-in 68.3%

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

      15. sub-neg 68.3%

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

      16. mul-1-neg 68.3%

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

      17. metadata-eval 68.3%

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

      18. associate-/r* 68.3%

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

      19. metadata-eval 68.3%

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

      20. metadata-eval 68.3%

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

      21. metadata-eval 68.3%

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

      22. metadata-eval 68.3%

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

      23. associate-*l/ 68.3%

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

   3. Simplified 68.3%

      \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
   4. Step-by-step derivation

      1. frac-sub 71.7%

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

      2. *-rgt-identity 71.7%

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

      3. metadata-eval 71.7%

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

      4. div-inv 71.7%

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

      5. associate-/r* 71.7%

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

      6. *-un-lft-identity 71.7%

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

      7. metadata-eval 71.7%

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

      8. div-inv 71.7%

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

      9. associate--l- 75.7%

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

      10. div-inv 75.7%

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

      11. metadata-eval 75.7%

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

      12. *-rgt-identity 75.7%

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

      13. div-inv 75.7%

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

      14. metadata-eval 75.7%

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

      15. *-rgt-identity 75.7%

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

   5. Applied egg-rr 75.7%

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

   6. Taylor expanded in x around inf 96.4%

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

4. Final simplification 74.4%

   \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;2\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{2}{x}}{-1 - x}\\ \end{array} \]

Alternative 4: 99.4% accurate, 1.2× speedup

Math

\[\begin{array}{l} \\ \frac{2}{\left(-1 - x\right) \cdot \left(x + -1\right)} \end{array} \]

FPCore

(FPCore (x) :precision binary64 (/ 2.0 (* (- -1.0 x) (+ x -1.0))))

C

double code(double x) {
	return 2.0 / ((-1.0 - x) * (x + -1.0));
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    code = 2.0d0 / (((-1.0d0) - x) * (x + (-1.0d0)))
end function

Java

public static double code(double x) {
	return 2.0 / ((-1.0 - x) * (x + -1.0));
}

Python

def code(x):
	return 2.0 / ((-1.0 - x) * (x + -1.0))

Julia

function code(x)
	return Float64(2.0 / Float64(Float64(-1.0 - x) * Float64(x + -1.0)))
end

MATLAB

function tmp = code(x)
	tmp = 2.0 / ((-1.0 - x) * (x + -1.0));
end

Wolfram

code[x_] := N[(2.0 / N[(N[(-1.0 - x), $MachinePrecision] * N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]

Derivation

1. Initial program 80.2%

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

   1. sub-neg 80.2%

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

   2. +-commutative 80.2%

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

   3. distribute-neg-frac 80.2%

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

   4. metadata-eval 80.2%

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

   5. metadata-eval 80.2%

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

   6. metadata-eval 80.2%

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

   7. associate-/r* 80.2%

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

   8. metadata-eval 80.2%

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

   9. neg-mul-1 80.2%

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

   10. sub0-neg 80.2%

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

   11. associate-+l- 80.2%

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

   12. neg-sub0 80.2%

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

   13. remove-double-neg 80.2%

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

   14. distribute-neg-in 80.2%

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

   15. sub-neg 80.2%

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

   16. mul-1-neg 80.2%

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

   17. metadata-eval 80.2%

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

   18. associate-/r* 80.2%

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

   19. metadata-eval 80.2%

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

   20. metadata-eval 80.2%

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

   21. metadata-eval 80.2%

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

   22. metadata-eval 80.2%

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

   23. associate-*l/ 80.2%

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

3. Simplified 80.2%

   \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
4. Step-by-step derivation

   1. sub-neg 80.2%

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

   2. distribute-neg-frac 80.2%

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

   3. metadata-eval 80.2%

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

5. Applied egg-rr 80.2%

   \[\leadsto \color{blue}{\frac{1}{1 - x} + \frac{-1}{-1 - x}} \]
6. Step-by-step derivation

   1. *-rgt-identity 80.2%

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

   2. cancel-sign-sub 80.2%

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

   3. distribute-neg-frac 80.2%

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

   4. metadata-eval 80.2%

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

   5. *-rgt-identity 80.2%

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

   6. *-inverses 80.2%

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

   7. associate-/r* 53.7%

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

   8. distribute-lft-neg-in 53.7%

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

   9. distribute-rgt-neg-in 53.7%

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

   10. *-commutative 53.7%

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

   11. *-lft-identity 53.7%

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

   12. *-inverses 53.7%

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

   13. times-frac 80.2%

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

   14. div-sub 81.2%

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

7. Simplified 99.5%

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

8. Final simplification 99.5%

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

Alternative 5: 51.3% accurate, 1.6× speedup

Math

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;2\\ \mathbf{else}:\\ \;\;\;\;\frac{-2}{1 + x}\\ \end{array} \end{array} \]

FPCore

(FPCore (x) :precision binary64 (if (<= x 1.0) 2.0 (/ -2.0 (+ 1.0 x))))

C

double code(double x) {
	double tmp;
	if (x <= 1.0) {
		tmp = 2.0;
	} else {
		tmp = -2.0 / (1.0 + x);
	}
	return tmp;
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 1.0d0) then
        tmp = 2.0d0
    else
        tmp = (-2.0d0) / (1.0d0 + x)
    end if
    code = tmp
end function

Java

public static double code(double x) {
	double tmp;
	if (x <= 1.0) {
		tmp = 2.0;
	} else {
		tmp = -2.0 / (1.0 + x);
	}
	return tmp;
}

Python

def code(x):
	tmp = 0
	if x <= 1.0:
		tmp = 2.0
	else:
		tmp = -2.0 / (1.0 + x)
	return tmp

Julia

function code(x)
	tmp = 0.0
	if (x <= 1.0)
		tmp = 2.0;
	else
		tmp = Float64(-2.0 / Float64(1.0 + x));
	end
	return tmp
end

MATLAB

function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 1.0)
		tmp = 2.0;
	else
		tmp = -2.0 / (1.0 + x);
	end
	tmp_2 = tmp;
end

Wolfram

code[x_] := If[LessEqual[x, 1.0], 2.0, N[(-2.0 / N[(1.0 + x), $MachinePrecision]), $MachinePrecision]]

Derivation

1. Split input into 2 regimes

2. if x < 1

   1. Initial program 84.5%

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

      1. sub-neg 84.5%

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

      2. +-commutative 84.5%

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

      3. distribute-neg-frac 84.5%

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

      4. metadata-eval 84.5%

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

      5. metadata-eval 84.5%

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

      6. metadata-eval 84.5%

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

      7. associate-/r* 84.5%

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

      8. metadata-eval 84.5%

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

      9. neg-mul-1 84.5%

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

      10. sub0-neg 84.5%

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

      11. associate-+l- 84.5%

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

      12. neg-sub0 84.5%

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

      13. remove-double-neg 84.5%

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

      14. distribute-neg-in 84.5%

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

      15. sub-neg 84.5%

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

      16. mul-1-neg 84.5%

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

      17. metadata-eval 84.5%

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

      18. associate-/r* 84.5%

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

      19. metadata-eval 84.5%

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

      20. metadata-eval 84.5%

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

      21. metadata-eval 84.5%

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

      22. metadata-eval 84.5%

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

      23. associate-*l/ 84.5%

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

   3. Simplified 84.5%

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

   4. Taylor expanded in x around 0 66.6%

      \[\leadsto \color{blue}{2} \]

   if 1 < x

   1. Initial program 68.3%

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

      1. sub-neg 68.3%

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

      2. +-commutative 68.3%

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

      3. distribute-neg-frac 68.3%

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

      4. metadata-eval 68.3%

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

      5. metadata-eval 68.3%

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

      6. metadata-eval 68.3%

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

      7. associate-/r* 68.3%

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

      8. metadata-eval 68.3%

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

      9. neg-mul-1 68.3%

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

      10. sub0-neg 68.3%

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

      11. associate-+l- 68.3%

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

      12. neg-sub0 68.3%

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

      13. remove-double-neg 68.3%

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

      14. distribute-neg-in 68.3%

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

      15. sub-neg 68.3%

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

      16. mul-1-neg 68.3%

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

      17. metadata-eval 68.3%

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

      18. associate-/r* 68.3%

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

      19. metadata-eval 68.3%

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

      20. metadata-eval 68.3%

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

      21. metadata-eval 68.3%

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

      22. metadata-eval 68.3%

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

      23. associate-*l/ 68.3%

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

   3. Simplified 68.3%

      \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
   4. Step-by-step derivation

      1. frac-sub 71.7%

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

      2. *-rgt-identity 71.7%

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

      3. metadata-eval 71.7%

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

      4. div-inv 71.7%

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

      5. associate-/r* 71.7%

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

      6. *-un-lft-identity 71.7%

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

      7. metadata-eval 71.7%

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

      8. div-inv 71.7%

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

      9. associate--l- 75.7%

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

      10. div-inv 75.7%

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

      11. metadata-eval 75.7%

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

      12. *-rgt-identity 75.7%

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

      13. div-inv 75.7%

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

      14. metadata-eval 75.7%

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

      15. *-rgt-identity 75.7%

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

   5. Applied egg-rr 75.7%

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

   6. Taylor expanded in x around 0 5.5%

      \[\leadsto \frac{\color{blue}{-2}}{-1 - x} \]
   7. Step-by-step derivation

      1. add-sqr-sqrt 5.5%

         \[\leadsto \color{blue}{\sqrt{\frac{-2}{-1 - x}} \cdot \sqrt{\frac{-2}{-1 - x}}} \]

      2. sqrt-unprod 60.8%

         \[\leadsto \color{blue}{\sqrt{\frac{-2}{-1 - x} \cdot \frac{-2}{-1 - x}}} \]

      3. frac-times 62.1%

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

      4. metadata-eval 62.1%

         \[\leadsto \sqrt{\frac{\color{blue}{4}}{\left(-1 - x\right) \cdot \left(-1 - x\right)}} \]

      5. metadata-eval 62.1%

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

      6. pow2 62.1%

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

      7. sub-neg 62.1%

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

      8. add-sqr-sqrt 0.0%

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

      9. sqrt-unprod 62.1%

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

      10. sqr-neg 62.1%

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

      11. sqrt-unprod 62.1%

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

      12. add-sqr-sqrt 62.1%

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

      13. +-commutative 62.1%

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

      14. pow2 62.1%

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

      15. frac-times 60.8%

          \[\leadsto \sqrt{\color{blue}{\frac{2}{x + -1} \cdot \frac{2}{x + -1}}} \]

      16. sqrt-unprod 5.5%

          \[\leadsto \color{blue}{\sqrt{\frac{2}{x + -1}} \cdot \sqrt{\frac{2}{x + -1}}} \]

      17. add-sqr-sqrt 5.5%

          \[\leadsto \color{blue}{\frac{2}{x + -1}} \]

      18. frac-2neg 5.5%

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

      19. metadata-eval 5.5%

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

      20. div-inv 5.5%

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

      21. +-commutative 5.5%

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

      22. distribute-neg-in 5.5%

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

      23. metadata-eval 5.5%

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

      24. add-sqr-sqrt 0.0%

          \[\leadsto -2 \cdot \frac{1}{1 + \color{blue}{\sqrt{-x} \cdot \sqrt{-x}}} \]

   8. Applied egg-rr 7.5%

      \[\leadsto \color{blue}{-2 \cdot \frac{1}{1 + x}} \]
   9. Step-by-step derivation

      1. associate-*r/ 7.5%

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

      2. metadata-eval 7.5%

         \[\leadsto \frac{\color{blue}{-2}}{1 + x} \]

      3. +-commutative 7.5%

         \[\leadsto \frac{-2}{\color{blue}{x + 1}} \]

   10. Simplified 7.5%

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

4. Final simplification 51.1%

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

Alternative 6: 51.3% accurate, 2.2× speedup

Math

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;2\\ \mathbf{else}:\\ \;\;\;\;\frac{-2}{x}\\ \end{array} \end{array} \]

FPCore

(FPCore (x) :precision binary64 (if (<= x 1.0) 2.0 (/ -2.0 x)))

C

double code(double x) {
	double tmp;
	if (x <= 1.0) {
		tmp = 2.0;
	} else {
		tmp = -2.0 / x;
	}
	return tmp;
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 1.0d0) then
        tmp = 2.0d0
    else
        tmp = (-2.0d0) / x
    end if
    code = tmp
end function

Java

public static double code(double x) {
	double tmp;
	if (x <= 1.0) {
		tmp = 2.0;
	} else {
		tmp = -2.0 / x;
	}
	return tmp;
}

Python

def code(x):
	tmp = 0
	if x <= 1.0:
		tmp = 2.0
	else:
		tmp = -2.0 / x
	return tmp

Julia

function code(x)
	tmp = 0.0
	if (x <= 1.0)
		tmp = 2.0;
	else
		tmp = Float64(-2.0 / x);
	end
	return tmp
end

MATLAB

function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 1.0)
		tmp = 2.0;
	else
		tmp = -2.0 / x;
	end
	tmp_2 = tmp;
end

Wolfram

code[x_] := If[LessEqual[x, 1.0], 2.0, N[(-2.0 / x), $MachinePrecision]]

Derivation

1. Split input into 2 regimes

2. if x < 1

   1. Initial program 84.5%

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

      1. sub-neg 84.5%

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

      2. +-commutative 84.5%

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

      3. distribute-neg-frac 84.5%

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

      4. metadata-eval 84.5%

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

      5. metadata-eval 84.5%

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

      6. metadata-eval 84.5%

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

      7. associate-/r* 84.5%

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

      8. metadata-eval 84.5%

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

      9. neg-mul-1 84.5%

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

      10. sub0-neg 84.5%

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

      11. associate-+l- 84.5%

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

      12. neg-sub0 84.5%

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

      13. remove-double-neg 84.5%

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

      14. distribute-neg-in 84.5%

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

      15. sub-neg 84.5%

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

      16. mul-1-neg 84.5%

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

      17. metadata-eval 84.5%

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

      18. associate-/r* 84.5%

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

      19. metadata-eval 84.5%

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

      20. metadata-eval 84.5%

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

      21. metadata-eval 84.5%

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

      22. metadata-eval 84.5%

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

      23. associate-*l/ 84.5%

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

   3. Simplified 84.5%

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

   4. Taylor expanded in x around 0 66.6%

      \[\leadsto \color{blue}{2} \]

   if 1 < x

   1. Initial program 68.3%

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

      1. sub-neg 68.3%

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

      2. +-commutative 68.3%

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

      3. distribute-neg-frac 68.3%

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

      4. metadata-eval 68.3%

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

      5. metadata-eval 68.3%

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

      6. metadata-eval 68.3%

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

      7. associate-/r* 68.3%

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

      8. metadata-eval 68.3%

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

      9. neg-mul-1 68.3%

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

      10. sub0-neg 68.3%

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

      11. associate-+l- 68.3%

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

      12. neg-sub0 68.3%

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

      13. remove-double-neg 68.3%

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

      14. distribute-neg-in 68.3%

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

      15. sub-neg 68.3%

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

      16. mul-1-neg 68.3%

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

      17. metadata-eval 68.3%

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

      18. associate-/r* 68.3%

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

      19. metadata-eval 68.3%

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

      20. metadata-eval 68.3%

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

      21. metadata-eval 68.3%

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

      22. metadata-eval 68.3%

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

      23. associate-*l/ 68.3%

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

   3. Simplified 68.3%

      \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
   4. Step-by-step derivation

      1. frac-sub 71.7%

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

      2. *-rgt-identity 71.7%

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

      3. metadata-eval 71.7%

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

      4. div-inv 71.7%

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

      5. associate-/r* 71.7%

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

      6. *-un-lft-identity 71.7%

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

      7. metadata-eval 71.7%

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

      8. div-inv 71.7%

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

      9. associate--l- 75.7%

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

      10. div-inv 75.7%

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

      11. metadata-eval 75.7%

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

      12. *-rgt-identity 75.7%

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

      13. div-inv 75.7%

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

      14. metadata-eval 75.7%

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

      15. *-rgt-identity 75.7%

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

   5. Applied egg-rr 75.7%

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

   6. Taylor expanded in x around 0 5.5%

      \[\leadsto \frac{\color{blue}{-2}}{-1 - x} \]
   7. Step-by-step derivation

      1. add-sqr-sqrt 5.5%

         \[\leadsto \color{blue}{\sqrt{\frac{-2}{-1 - x}} \cdot \sqrt{\frac{-2}{-1 - x}}} \]

      2. sqrt-unprod 60.8%

         \[\leadsto \color{blue}{\sqrt{\frac{-2}{-1 - x} \cdot \frac{-2}{-1 - x}}} \]

      3. frac-times 62.1%

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

      4. metadata-eval 62.1%

         \[\leadsto \sqrt{\frac{\color{blue}{4}}{\left(-1 - x\right) \cdot \left(-1 - x\right)}} \]

      5. metadata-eval 62.1%

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

      6. pow2 62.1%

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

      7. sub-neg 62.1%

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

      8. add-sqr-sqrt 0.0%

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

      9. sqrt-unprod 62.1%

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

      10. sqr-neg 62.1%

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

      11. sqrt-unprod 62.1%

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

      12. add-sqr-sqrt 62.1%

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

      13. +-commutative 62.1%

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

      14. pow2 62.1%

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

      15. frac-times 60.8%

          \[\leadsto \sqrt{\color{blue}{\frac{2}{x + -1} \cdot \frac{2}{x + -1}}} \]

      16. sqrt-unprod 5.5%

          \[\leadsto \color{blue}{\sqrt{\frac{2}{x + -1}} \cdot \sqrt{\frac{2}{x + -1}}} \]

      17. add-sqr-sqrt 5.5%

          \[\leadsto \color{blue}{\frac{2}{x + -1}} \]

      18. frac-2neg 5.5%

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

      19. metadata-eval 5.5%

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

      20. div-inv 5.5%

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

      21. +-commutative 5.5%

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

      22. distribute-neg-in 5.5%

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

      23. metadata-eval 5.5%

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

      24. add-sqr-sqrt 0.0%

          \[\leadsto -2 \cdot \frac{1}{1 + \color{blue}{\sqrt{-x} \cdot \sqrt{-x}}} \]

   8. Applied egg-rr 7.5%

      \[\leadsto \color{blue}{-2 \cdot \frac{1}{1 + x}} \]
   9. Step-by-step derivation

      1. associate-*r/ 7.5%

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

      2. metadata-eval 7.5%

         \[\leadsto \frac{\color{blue}{-2}}{1 + x} \]

      3. +-commutative 7.5%

         \[\leadsto \frac{-2}{\color{blue}{x + 1}} \]

   10. Simplified 7.5%

       \[\leadsto \color{blue}{\frac{-2}{x + 1}} \]

   11. Taylor expanded in x around inf 7.5%

       \[\leadsto \color{blue}{\frac{-2}{x}} \]
3. Recombined 2 regimes into one program.

4. Final simplification 51.1%

   \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;2\\ \mathbf{else}:\\ \;\;\;\;\frac{-2}{x}\\ \end{array} \]

Alternative 7: 2.9% accurate, 11.0× speedup

Math

\[\begin{array}{l} \\ -2 \end{array} \]

FPCore

(FPCore (x) :precision binary64 -2.0)

C

double code(double x) {
	return -2.0;
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    code = -2.0d0
end function

Java

public static double code(double x) {
	return -2.0;
}

Python

def code(x):
	return -2.0

Julia

function code(x)
	return -2.0
end

MATLAB

function tmp = code(x)
	tmp = -2.0;
end

Wolfram

code[x_] := -2.0

Derivation

1. Initial program 80.2%

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

   1. sub-neg 80.2%

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

   2. +-commutative 80.2%

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

   3. distribute-neg-frac 80.2%

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

   4. metadata-eval 80.2%

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

   5. metadata-eval 80.2%

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

   6. metadata-eval 80.2%

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

   7. associate-/r* 80.2%

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

   8. metadata-eval 80.2%

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

   9. neg-mul-1 80.2%

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

   10. sub0-neg 80.2%

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

   11. associate-+l- 80.2%

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

   12. neg-sub0 80.2%

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

   13. remove-double-neg 80.2%

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

   14. distribute-neg-in 80.2%

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

   15. sub-neg 80.2%

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

   16. mul-1-neg 80.2%

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

   17. metadata-eval 80.2%

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

   18. associate-/r* 80.2%

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

   19. metadata-eval 80.2%

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

   20. metadata-eval 80.2%

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

   21. metadata-eval 80.2%

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

   22. metadata-eval 80.2%

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

   23. associate-*l/ 80.2%

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

3. Simplified 80.2%

   \[\leadsto \color{blue}{\frac{1}{1 - x} - \frac{1}{-1 - x}} \]
4. Step-by-step derivation

   1. frac-sub 81.2%

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

   2. *-rgt-identity 81.2%

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

   3. metadata-eval 81.2%

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

   4. div-inv 81.2%

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

   5. associate-/r* 81.2%

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

   6. *-un-lft-identity 81.2%

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

   7. metadata-eval 81.2%

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

   8. div-inv 81.2%

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

   9. associate--l- 83.7%

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

   10. div-inv 83.7%

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

   11. metadata-eval 83.7%

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

   12. *-rgt-identity 83.7%

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

   13. div-inv 83.7%

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

   14. metadata-eval 83.7%

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

   15. *-rgt-identity 83.7%

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

5. Applied egg-rr 83.7%

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

6. Taylor expanded in x around 0 50.8%

   \[\leadsto \frac{\color{blue}{-2}}{-1 - x} \]
7. Step-by-step derivation

   1. add-sqr-sqrt 48.5%

      \[\leadsto \color{blue}{\sqrt{\frac{-2}{-1 - x}} \cdot \sqrt{\frac{-2}{-1 - x}}} \]

   2. sqrt-unprod 76.2%

      \[\leadsto \color{blue}{\sqrt{\frac{-2}{-1 - x} \cdot \frac{-2}{-1 - x}}} \]

   3. frac-times 77.0%

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

   4. metadata-eval 77.0%

      \[\leadsto \sqrt{\frac{\color{blue}{4}}{\left(-1 - x\right) \cdot \left(-1 - x\right)}} \]

   5. metadata-eval 77.0%

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

   6. pow2 77.0%

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

   7. sub-neg 77.0%

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

   8. add-sqr-sqrt 35.6%

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

   9. sqrt-unprod 77.0%

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

   10. sqr-neg 77.0%

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

   11. sqrt-unprod 41.4%

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

   12. add-sqr-sqrt 77.0%

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

   13. +-commutative 77.0%

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

   14. pow2 77.0%

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

   15. frac-times 76.2%

       \[\leadsto \sqrt{\color{blue}{\frac{2}{x + -1} \cdot \frac{2}{x + -1}}} \]

   16. sqrt-unprod 1.4%

       \[\leadsto \color{blue}{\sqrt{\frac{2}{x + -1}} \cdot \sqrt{\frac{2}{x + -1}}} \]

   17. add-sqr-sqrt 3.8%

       \[\leadsto \color{blue}{\frac{2}{x + -1}} \]

   18. frac-2neg 3.8%

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

   19. metadata-eval 3.8%

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

   20. div-inv 3.8%

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

   21. +-commutative 3.8%

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

   22. distribute-neg-in 3.8%

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

   23. metadata-eval 3.8%

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

   24. add-sqr-sqrt 1.9%

       \[\leadsto -2 \cdot \frac{1}{1 + \color{blue}{\sqrt{-x} \cdot \sqrt{-x}}} \]

8. Applied egg-rr 3.9%

   \[\leadsto \color{blue}{-2 \cdot \frac{1}{1 + x}} \]
9. Step-by-step derivation

   1. associate-*r/ 3.9%

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

   2. metadata-eval 3.9%

      \[\leadsto \frac{\color{blue}{-2}}{1 + x} \]

   3. +-commutative 3.9%

      \[\leadsto \frac{-2}{\color{blue}{x + 1}} \]

10. Simplified 3.9%

    \[\leadsto \color{blue}{\frac{-2}{x + 1}} \]

11. Taylor expanded in x around 0 2.9%

    \[\leadsto \color{blue}{-2} \]

12. Final simplification 2.9%

    \[\leadsto -2 \]

Alternative 8: 50.3% accurate, 11.0× speedup

Math

\[\begin{array}{l} \\ 2 \end{array} \]

FPCore

(FPCore (x) :precision binary64 2.0)

C

double code(double x) {
	return 2.0;
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    code = 2.0d0
end function

Java

public static double code(double x) {
	return 2.0;
}

Python

def code(x):
	return 2.0

Julia

function code(x)
	return 2.0
end

MATLAB

function tmp = code(x)
	tmp = 2.0;
end

Wolfram

code[x_] := 2.0

Derivation

1. Initial program 80.2%

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

   1. sub-neg 80.2%

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

   2. +-commutative 80.2%

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

   3. distribute-neg-frac 80.2%

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

   4. metadata-eval 80.2%

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

   5. metadata-eval 80.2%

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

   6. metadata-eval 80.2%

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

   7. associate-/r* 80.2%

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

   8. metadata-eval 80.2%

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

   9. neg-mul-1 80.2%

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

   10. sub0-neg 80.2%

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

   11. associate-+l- 80.2%

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

   12. neg-sub0 80.2%

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

   13. remove-double-neg 80.2%

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

   14. distribute-neg-in 80.2%

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

   15. sub-neg 80.2%

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

   16. mul-1-neg 80.2%

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

   17. metadata-eval 80.2%

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

   18. associate-/r* 80.2%

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

   19. metadata-eval 80.2%

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

   20. metadata-eval 80.2%

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

   21. metadata-eval 80.2%

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

   22. metadata-eval 80.2%

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

   23. associate-*l/ 80.2%

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

3. Simplified 80.2%

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

4. Taylor expanded in x around 0 49.9%

   \[\leadsto \color{blue}{2} \]

5. Final simplification 49.9%

   \[\leadsto 2 \]

Reproduce

herbie shell --seed 2023319 
(FPCore (x)
  :name "Asymptote A"
  :precision binary64
  (- (/ 1.0 (+ x 1.0)) (/ 1.0 (- x 1.0))))