2frac (problem 3.3.1)

Percentage Accurate: 77.9% → 99.9%
Time: 6.0s
Alternatives: 7
Speedup: 1.0×

Specification

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

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

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 7 alternatives:

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

Initial Program: 77.9% accurate, 1.0× speedup?

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

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

Alternative 1: 99.9% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1}{1 + x} - \frac{1}{x}\\ \mathbf{if}\;t\_0 \leq -5 \cdot 10^{-22}:\\ \;\;\;\;\frac{x - \left(1 + x\right)}{x \cdot \left(1 + x\right)}\\ \mathbf{elif}\;t\_0 \leq 0:\\ \;\;\;\;-{x}^{-2}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (- (/ 1.0 (+ 1.0 x)) (/ 1.0 x))))
   (if (<= t_0 -5e-22)
     (/ (- x (+ 1.0 x)) (* x (+ 1.0 x)))
     (if (<= t_0 0.0) (- (pow x -2.0)) t_0))))
double code(double x) {
	double t_0 = (1.0 / (1.0 + x)) - (1.0 / x);
	double tmp;
	if (t_0 <= -5e-22) {
		tmp = (x - (1.0 + x)) / (x * (1.0 + x));
	} else if (t_0 <= 0.0) {
		tmp = -pow(x, -2.0);
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (1.0d0 / (1.0d0 + x)) - (1.0d0 / x)
    if (t_0 <= (-5d-22)) then
        tmp = (x - (1.0d0 + x)) / (x * (1.0d0 + x))
    else if (t_0 <= 0.0d0) then
        tmp = -(x ** (-2.0d0))
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = (1.0 / (1.0 + x)) - (1.0 / x);
	double tmp;
	if (t_0 <= -5e-22) {
		tmp = (x - (1.0 + x)) / (x * (1.0 + x));
	} else if (t_0 <= 0.0) {
		tmp = -Math.pow(x, -2.0);
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x):
	t_0 = (1.0 / (1.0 + x)) - (1.0 / x)
	tmp = 0
	if t_0 <= -5e-22:
		tmp = (x - (1.0 + x)) / (x * (1.0 + x))
	elif t_0 <= 0.0:
		tmp = -math.pow(x, -2.0)
	else:
		tmp = t_0
	return tmp
function code(x)
	t_0 = Float64(Float64(1.0 / Float64(1.0 + x)) - Float64(1.0 / x))
	tmp = 0.0
	if (t_0 <= -5e-22)
		tmp = Float64(Float64(x - Float64(1.0 + x)) / Float64(x * Float64(1.0 + x)));
	elseif (t_0 <= 0.0)
		tmp = Float64(-(x ^ -2.0));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = (1.0 / (1.0 + x)) - (1.0 / x);
	tmp = 0.0;
	if (t_0 <= -5e-22)
		tmp = (x - (1.0 + x)) / (x * (1.0 + x));
	elseif (t_0 <= 0.0)
		tmp = -(x ^ -2.0);
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(N[(1.0 / N[(1.0 + x), $MachinePrecision]), $MachinePrecision] - N[(1.0 / x), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -5e-22], N[(N[(x - N[(1.0 + x), $MachinePrecision]), $MachinePrecision] / N[(x * N[(1.0 + x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$0, 0.0], (-N[Power[x, -2.0], $MachinePrecision]), t$95$0]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{1}{1 + x} - \frac{1}{x}\\
\mathbf{if}\;t\_0 \leq -5 \cdot 10^{-22}:\\
\;\;\;\;\frac{x - \left(1 + x\right)}{x \cdot \left(1 + x\right)}\\

\mathbf{elif}\;t\_0 \leq 0:\\
\;\;\;\;-{x}^{-2}\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (-.f64 (/.f64 #s(literal 1 binary64) (+.f64 x #s(literal 1 binary64))) (/.f64 #s(literal 1 binary64) x)) < -4.99999999999999954e-22

    1. Initial program 96.9%

      \[\frac{1}{x + 1} - \frac{1}{x} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. clear-num96.9%

        \[\leadsto \color{blue}{\frac{1}{\frac{x + 1}{1}}} - \frac{1}{x} \]
      2. frac-sub99.9%

        \[\leadsto \color{blue}{\frac{1 \cdot x - \frac{x + 1}{1} \cdot 1}{\frac{x + 1}{1} \cdot x}} \]
      3. *-un-lft-identity99.9%

        \[\leadsto \frac{\color{blue}{x} - \frac{x + 1}{1} \cdot 1}{\frac{x + 1}{1} \cdot x} \]
      4. div-inv99.9%

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

        \[\leadsto \frac{x - \left(\left(x + 1\right) \cdot \color{blue}{1}\right) \cdot 1}{\frac{x + 1}{1} \cdot x} \]
      6. *-rgt-identity99.9%

        \[\leadsto \frac{x - \color{blue}{\left(x + 1\right)} \cdot 1}{\frac{x + 1}{1} \cdot x} \]
      7. *-rgt-identity99.9%

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

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

        \[\leadsto \frac{x - \left(1 + x\right)}{\color{blue}{x \cdot \frac{x + 1}{1}}} \]
      10. div-inv99.9%

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

        \[\leadsto \frac{x - \left(1 + x\right)}{x \cdot \left(\left(x + 1\right) \cdot \color{blue}{1}\right)} \]
      12. *-rgt-identity99.9%

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

        \[\leadsto \frac{x - \left(1 + x\right)}{x \cdot \color{blue}{\left(1 + x\right)}} \]
    4. Applied egg-rr99.9%

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

    if -4.99999999999999954e-22 < (-.f64 (/.f64 #s(literal 1 binary64) (+.f64 x #s(literal 1 binary64))) (/.f64 #s(literal 1 binary64) x)) < 0.0

    1. Initial program 57.5%

      \[\frac{1}{x + 1} - \frac{1}{x} \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf 99.1%

      \[\leadsto \color{blue}{\frac{-1}{{x}^{2}}} \]
    4. Step-by-step derivation
      1. div-inv99.1%

        \[\leadsto \color{blue}{-1 \cdot \frac{1}{{x}^{2}}} \]
      2. pow-flip100.0%

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

        \[\leadsto -1 \cdot {x}^{\color{blue}{-2}} \]
    5. Applied egg-rr100.0%

      \[\leadsto \color{blue}{-1 \cdot {x}^{-2}} \]
    6. Step-by-step derivation
      1. neg-mul-1100.0%

        \[\leadsto \color{blue}{-{x}^{-2}} \]
    7. Simplified100.0%

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

    if 0.0 < (-.f64 (/.f64 #s(literal 1 binary64) (+.f64 x #s(literal 1 binary64))) (/.f64 #s(literal 1 binary64) x))

    1. Initial program 100.0%

      \[\frac{1}{x + 1} - \frac{1}{x} \]
    2. Add Preprocessing
  3. Recombined 3 regimes into one program.
  4. Final simplification100.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{1}{1 + x} - \frac{1}{x} \leq -5 \cdot 10^{-22}:\\ \;\;\;\;\frac{x - \left(1 + x\right)}{x \cdot \left(1 + x\right)}\\ \mathbf{elif}\;\frac{1}{1 + x} - \frac{1}{x} \leq 0:\\ \;\;\;\;-{x}^{-2}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{1 + x} - \frac{1}{x}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 76.3% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1:\\ \;\;\;\;0\\ \mathbf{elif}\;x \leq 3.9 \cdot 10^{+61}:\\ \;\;\;\;\left(1 - x\right) + \frac{-1}{x}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.0) 0.0 (if (<= x 3.9e+61) (+ (- 1.0 x) (/ -1.0 x)) 0.0)))
double code(double x) {
	double tmp;
	if (x <= -1.0) {
		tmp = 0.0;
	} else if (x <= 3.9e+61) {
		tmp = (1.0 - x) + (-1.0 / x);
	} else {
		tmp = 0.0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1.0d0)) then
        tmp = 0.0d0
    else if (x <= 3.9d+61) then
        tmp = (1.0d0 - x) + ((-1.0d0) / x)
    else
        tmp = 0.0d0
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -1.0) {
		tmp = 0.0;
	} else if (x <= 3.9e+61) {
		tmp = (1.0 - x) + (-1.0 / x);
	} else {
		tmp = 0.0;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -1.0:
		tmp = 0.0
	elif x <= 3.9e+61:
		tmp = (1.0 - x) + (-1.0 / x)
	else:
		tmp = 0.0
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -1.0)
		tmp = 0.0;
	elseif (x <= 3.9e+61)
		tmp = Float64(Float64(1.0 - x) + Float64(-1.0 / x));
	else
		tmp = 0.0;
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1.0)
		tmp = 0.0;
	elseif (x <= 3.9e+61)
		tmp = (1.0 - x) + (-1.0 / x);
	else
		tmp = 0.0;
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -1.0], 0.0, If[LessEqual[x, 3.9e+61], N[(N[(1.0 - x), $MachinePrecision] + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision], 0.0]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1:\\
\;\;\;\;0\\

\mathbf{elif}\;x \leq 3.9 \cdot 10^{+61}:\\
\;\;\;\;\left(1 - x\right) + \frac{-1}{x}\\

\mathbf{else}:\\
\;\;\;\;0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1 or 3.89999999999999987e61 < x

    1. Initial program 65.4%

      \[\frac{1}{x + 1} - \frac{1}{x} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. *-un-lft-identity65.4%

        \[\leadsto \color{blue}{1 \cdot \frac{1}{x + 1}} - \frac{1}{x} \]
      2. inv-pow65.4%

        \[\leadsto 1 \cdot \frac{1}{x + 1} - \color{blue}{{x}^{-1}} \]
      3. add-sqr-sqrt22.7%

        \[\leadsto 1 \cdot \frac{1}{x + 1} - {\color{blue}{\left(\sqrt{x} \cdot \sqrt{x}\right)}}^{-1} \]
      4. unpow-prod-down16.8%

        \[\leadsto 1 \cdot \frac{1}{x + 1} - \color{blue}{{\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}} \]
      5. prod-diff5.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left(1, \frac{1}{x + 1}, -{\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right)} \]
      6. unpow-prod-down5.3%

        \[\leadsto \mathsf{fma}\left(1, \frac{1}{x + 1}, -\color{blue}{{\left(\sqrt{x} \cdot \sqrt{x}\right)}^{-1}}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      7. add-sqr-sqrt5.2%

        \[\leadsto \mathsf{fma}\left(1, \frac{1}{x + 1}, -{\color{blue}{x}}^{-1}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      8. inv-pow5.2%

        \[\leadsto \mathsf{fma}\left(1, \frac{1}{x + 1}, -\color{blue}{\frac{1}{x}}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      9. fma-define5.2%

        \[\leadsto \color{blue}{\left(1 \cdot \frac{1}{x + 1} + \left(-\frac{1}{x}\right)\right)} + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      10. *-un-lft-identity5.2%

        \[\leadsto \left(\color{blue}{\frac{1}{x + 1}} + \left(-\frac{1}{x}\right)\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      11. +-commutative5.2%

        \[\leadsto \left(\frac{1}{\color{blue}{1 + x}} + \left(-\frac{1}{x}\right)\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      12. distribute-neg-frac5.2%

        \[\leadsto \left(\frac{1}{1 + x} + \color{blue}{\frac{-1}{x}}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      13. metadata-eval5.2%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{\color{blue}{-1}}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      14. unpow-prod-down5.3%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, \color{blue}{{\left(\sqrt{x} \cdot \sqrt{x}\right)}^{-1}}\right) \]
      15. add-sqr-sqrt5.4%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\color{blue}{x}}^{-1}\right) \]
      16. inv-pow5.4%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, \color{blue}{\frac{1}{x}}\right) \]
    4. Applied egg-rr5.4%

      \[\leadsto \color{blue}{\left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, \frac{1}{x}\right)} \]
    5. Step-by-step derivation
      1. fma-undefine16.8%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \color{blue}{\left(\left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} + \frac{1}{x}\right)} \]
      2. +-commutative16.8%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \color{blue}{\left(\frac{1}{x} + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1}\right)} \]
      3. associate-+r+16.8%

        \[\leadsto \color{blue}{\left(\left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \frac{1}{x}\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1}} \]
      4. associate-+r+16.8%

        \[\leadsto \color{blue}{\left(\frac{1}{1 + x} + \left(\frac{-1}{x} + \frac{1}{x}\right)\right)} + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      5. *-rgt-identity16.8%

        \[\leadsto \left(\frac{1}{1 + x} + \left(\color{blue}{\frac{-1}{x} \cdot 1} + \frac{1}{x}\right)\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      6. metadata-eval16.8%

        \[\leadsto \left(\frac{1}{1 + x} + \left(\frac{-1}{x} \cdot 1 + \frac{\color{blue}{-1 \cdot -1}}{x}\right)\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      7. associate-*l/16.8%

        \[\leadsto \left(\frac{1}{1 + x} + \left(\frac{-1}{x} \cdot 1 + \color{blue}{\frac{-1}{x} \cdot -1}\right)\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      8. distribute-lft-out16.8%

        \[\leadsto \left(\frac{1}{1 + x} + \color{blue}{\frac{-1}{x} \cdot \left(1 + -1\right)}\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      9. metadata-eval16.8%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x} \cdot \color{blue}{0}\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      10. mul0-rgt16.8%

        \[\leadsto \left(\frac{1}{1 + x} + \color{blue}{0}\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      11. +-rgt-identity16.8%

        \[\leadsto \color{blue}{\frac{1}{1 + x}} + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
    6. Simplified14.5%

      \[\leadsto \color{blue}{\frac{-1}{-1 - x} + \left(-{\left(\sqrt{x}\right)}^{-2}\right)} \]
    7. Taylor expanded in x around -inf 0.0%

      \[\leadsto \color{blue}{\frac{1 + \frac{1}{{\left(\sqrt{-1}\right)}^{2}}}{x}} \]
    8. Step-by-step derivation
      1. unpow20.0%

        \[\leadsto \frac{1 + \frac{1}{\color{blue}{\sqrt{-1} \cdot \sqrt{-1}}}}{x} \]
      2. rem-square-sqrt63.6%

        \[\leadsto \frac{1 + \frac{1}{\color{blue}{-1}}}{x} \]
      3. metadata-eval63.6%

        \[\leadsto \frac{1 + \color{blue}{-1}}{x} \]
      4. metadata-eval63.6%

        \[\leadsto \frac{\color{blue}{0}}{x} \]
      5. metadata-eval63.6%

        \[\leadsto \frac{\color{blue}{0 \cdot -1}}{x} \]
      6. associate-*r/63.6%

        \[\leadsto \color{blue}{0 \cdot \frac{-1}{x}} \]
      7. mul0-lft63.6%

        \[\leadsto \color{blue}{0} \]
    9. Simplified63.6%

      \[\leadsto \color{blue}{0} \]

    if -1 < x < 3.89999999999999987e61

    1. Initial program 88.3%

      \[\frac{1}{x + 1} - \frac{1}{x} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 86.5%

      \[\leadsto \color{blue}{\left(1 + -1 \cdot x\right)} - \frac{1}{x} \]
    4. Step-by-step derivation
      1. neg-mul-186.5%

        \[\leadsto \left(1 + \color{blue}{\left(-x\right)}\right) - \frac{1}{x} \]
      2. unsub-neg86.5%

        \[\leadsto \color{blue}{\left(1 - x\right)} - \frac{1}{x} \]
    5. Simplified86.5%

      \[\leadsto \color{blue}{\left(1 - x\right)} - \frac{1}{x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification76.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1:\\ \;\;\;\;0\\ \mathbf{elif}\;x \leq 3.9 \cdot 10^{+61}:\\ \;\;\;\;\left(1 - x\right) + \frac{-1}{x}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 76.0% accurate, 0.6× speedup?

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

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1:\\
\;\;\;\;0\\

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

\mathbf{else}:\\
\;\;\;\;0\\


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

    1. Initial program 57.9%

      \[\frac{1}{x + 1} - \frac{1}{x} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. *-un-lft-identity57.9%

        \[\leadsto \color{blue}{1 \cdot \frac{1}{x + 1}} - \frac{1}{x} \]
      2. inv-pow57.9%

        \[\leadsto 1 \cdot \frac{1}{x + 1} - \color{blue}{{x}^{-1}} \]
      3. add-sqr-sqrt21.4%

        \[\leadsto 1 \cdot \frac{1}{x + 1} - {\color{blue}{\left(\sqrt{x} \cdot \sqrt{x}\right)}}^{-1} \]
      4. unpow-prod-down16.4%

        \[\leadsto 1 \cdot \frac{1}{x + 1} - \color{blue}{{\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}} \]
      5. prod-diff6.8%

        \[\leadsto \color{blue}{\mathsf{fma}\left(1, \frac{1}{x + 1}, -{\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right)} \]
      6. unpow-prod-down6.8%

        \[\leadsto \mathsf{fma}\left(1, \frac{1}{x + 1}, -\color{blue}{{\left(\sqrt{x} \cdot \sqrt{x}\right)}^{-1}}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      7. add-sqr-sqrt6.7%

        \[\leadsto \mathsf{fma}\left(1, \frac{1}{x + 1}, -{\color{blue}{x}}^{-1}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      8. inv-pow6.7%

        \[\leadsto \mathsf{fma}\left(1, \frac{1}{x + 1}, -\color{blue}{\frac{1}{x}}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      9. fma-define6.7%

        \[\leadsto \color{blue}{\left(1 \cdot \frac{1}{x + 1} + \left(-\frac{1}{x}\right)\right)} + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      10. *-un-lft-identity6.7%

        \[\leadsto \left(\color{blue}{\frac{1}{x + 1}} + \left(-\frac{1}{x}\right)\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      11. +-commutative6.7%

        \[\leadsto \left(\frac{1}{\color{blue}{1 + x}} + \left(-\frac{1}{x}\right)\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      12. distribute-neg-frac6.7%

        \[\leadsto \left(\frac{1}{1 + x} + \color{blue}{\frac{-1}{x}}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      13. metadata-eval6.7%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{\color{blue}{-1}}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      14. unpow-prod-down6.8%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, \color{blue}{{\left(\sqrt{x} \cdot \sqrt{x}\right)}^{-1}}\right) \]
      15. add-sqr-sqrt6.8%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\color{blue}{x}}^{-1}\right) \]
      16. inv-pow6.8%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, \color{blue}{\frac{1}{x}}\right) \]
    4. Applied egg-rr6.8%

      \[\leadsto \color{blue}{\left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, \frac{1}{x}\right)} \]
    5. Step-by-step derivation
      1. fma-undefine16.4%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \color{blue}{\left(\left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} + \frac{1}{x}\right)} \]
      2. +-commutative16.4%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \color{blue}{\left(\frac{1}{x} + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1}\right)} \]
      3. associate-+r+16.4%

        \[\leadsto \color{blue}{\left(\left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \frac{1}{x}\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1}} \]
      4. associate-+r+16.4%

        \[\leadsto \color{blue}{\left(\frac{1}{1 + x} + \left(\frac{-1}{x} + \frac{1}{x}\right)\right)} + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      5. *-rgt-identity16.4%

        \[\leadsto \left(\frac{1}{1 + x} + \left(\color{blue}{\frac{-1}{x} \cdot 1} + \frac{1}{x}\right)\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      6. metadata-eval16.4%

        \[\leadsto \left(\frac{1}{1 + x} + \left(\frac{-1}{x} \cdot 1 + \frac{\color{blue}{-1 \cdot -1}}{x}\right)\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      7. associate-*l/16.4%

        \[\leadsto \left(\frac{1}{1 + x} + \left(\frac{-1}{x} \cdot 1 + \color{blue}{\frac{-1}{x} \cdot -1}\right)\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      8. distribute-lft-out16.4%

        \[\leadsto \left(\frac{1}{1 + x} + \color{blue}{\frac{-1}{x} \cdot \left(1 + -1\right)}\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      9. metadata-eval16.4%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x} \cdot \color{blue}{0}\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      10. mul0-rgt16.4%

        \[\leadsto \left(\frac{1}{1 + x} + \color{blue}{0}\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      11. +-rgt-identity16.4%

        \[\leadsto \color{blue}{\frac{1}{1 + x}} + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
    6. Simplified14.4%

      \[\leadsto \color{blue}{\frac{-1}{-1 - x} + \left(-{\left(\sqrt{x}\right)}^{-2}\right)} \]
    7. Taylor expanded in x around -inf 0.0%

      \[\leadsto \color{blue}{\frac{1 + \frac{1}{{\left(\sqrt{-1}\right)}^{2}}}{x}} \]
    8. Step-by-step derivation
      1. unpow20.0%

        \[\leadsto \frac{1 + \frac{1}{\color{blue}{\sqrt{-1} \cdot \sqrt{-1}}}}{x} \]
      2. rem-square-sqrt55.0%

        \[\leadsto \frac{1 + \frac{1}{\color{blue}{-1}}}{x} \]
      3. metadata-eval55.0%

        \[\leadsto \frac{1 + \color{blue}{-1}}{x} \]
      4. metadata-eval55.0%

        \[\leadsto \frac{\color{blue}{0}}{x} \]
      5. metadata-eval55.0%

        \[\leadsto \frac{\color{blue}{0 \cdot -1}}{x} \]
      6. associate-*r/55.0%

        \[\leadsto \color{blue}{0 \cdot \frac{-1}{x}} \]
      7. mul0-lft55.0%

        \[\leadsto \color{blue}{0} \]
    9. Simplified55.0%

      \[\leadsto \color{blue}{0} \]

    if -1 < x < 1

    1. Initial program 100.0%

      \[\frac{1}{x + 1} - \frac{1}{x} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 98.2%

      \[\leadsto \color{blue}{\frac{x - 1}{x}} \]
    4. Step-by-step derivation
      1. div-sub98.2%

        \[\leadsto \color{blue}{\frac{x}{x} - \frac{1}{x}} \]
      2. *-inverses98.2%

        \[\leadsto \color{blue}{1} - \frac{1}{x} \]
    5. Simplified98.2%

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

Alternative 4: 75.8% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1:\\ \;\;\;\;0\\ \mathbf{elif}\;x \leq 4.5 \cdot 10^{+102}:\\ \;\;\;\;\frac{-1}{x}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.0) 0.0 (if (<= x 4.5e+102) (/ -1.0 x) 0.0)))
double code(double x) {
	double tmp;
	if (x <= -1.0) {
		tmp = 0.0;
	} else if (x <= 4.5e+102) {
		tmp = -1.0 / x;
	} else {
		tmp = 0.0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1.0d0)) then
        tmp = 0.0d0
    else if (x <= 4.5d+102) then
        tmp = (-1.0d0) / x
    else
        tmp = 0.0d0
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -1.0) {
		tmp = 0.0;
	} else if (x <= 4.5e+102) {
		tmp = -1.0 / x;
	} else {
		tmp = 0.0;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -1.0:
		tmp = 0.0
	elif x <= 4.5e+102:
		tmp = -1.0 / x
	else:
		tmp = 0.0
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -1.0)
		tmp = 0.0;
	elseif (x <= 4.5e+102)
		tmp = Float64(-1.0 / x);
	else
		tmp = 0.0;
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1.0)
		tmp = 0.0;
	elseif (x <= 4.5e+102)
		tmp = -1.0 / x;
	else
		tmp = 0.0;
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -1.0], 0.0, If[LessEqual[x, 4.5e+102], N[(-1.0 / x), $MachinePrecision], 0.0]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1:\\
\;\;\;\;0\\

\mathbf{elif}\;x \leq 4.5 \cdot 10^{+102}:\\
\;\;\;\;\frac{-1}{x}\\

\mathbf{else}:\\
\;\;\;\;0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1 or 4.50000000000000021e102 < x

    1. Initial program 69.9%

      \[\frac{1}{x + 1} - \frac{1}{x} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. *-un-lft-identity69.9%

        \[\leadsto \color{blue}{1 \cdot \frac{1}{x + 1}} - \frac{1}{x} \]
      2. inv-pow69.9%

        \[\leadsto 1 \cdot \frac{1}{x + 1} - \color{blue}{{x}^{-1}} \]
      3. add-sqr-sqrt24.0%

        \[\leadsto 1 \cdot \frac{1}{x + 1} - {\color{blue}{\left(\sqrt{x} \cdot \sqrt{x}\right)}}^{-1} \]
      4. unpow-prod-down17.6%

        \[\leadsto 1 \cdot \frac{1}{x + 1} - \color{blue}{{\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}} \]
      5. prod-diff5.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left(1, \frac{1}{x + 1}, -{\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right)} \]
      6. unpow-prod-down5.4%

        \[\leadsto \mathsf{fma}\left(1, \frac{1}{x + 1}, -\color{blue}{{\left(\sqrt{x} \cdot \sqrt{x}\right)}^{-1}}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      7. add-sqr-sqrt5.4%

        \[\leadsto \mathsf{fma}\left(1, \frac{1}{x + 1}, -{\color{blue}{x}}^{-1}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      8. inv-pow5.4%

        \[\leadsto \mathsf{fma}\left(1, \frac{1}{x + 1}, -\color{blue}{\frac{1}{x}}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      9. fma-define5.4%

        \[\leadsto \color{blue}{\left(1 \cdot \frac{1}{x + 1} + \left(-\frac{1}{x}\right)\right)} + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      10. *-un-lft-identity5.4%

        \[\leadsto \left(\color{blue}{\frac{1}{x + 1}} + \left(-\frac{1}{x}\right)\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      11. +-commutative5.4%

        \[\leadsto \left(\frac{1}{\color{blue}{1 + x}} + \left(-\frac{1}{x}\right)\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      12. distribute-neg-frac5.4%

        \[\leadsto \left(\frac{1}{1 + x} + \color{blue}{\frac{-1}{x}}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      13. metadata-eval5.4%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{\color{blue}{-1}}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
      14. unpow-prod-down5.4%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, \color{blue}{{\left(\sqrt{x} \cdot \sqrt{x}\right)}^{-1}}\right) \]
      15. add-sqr-sqrt5.4%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\color{blue}{x}}^{-1}\right) \]
      16. inv-pow5.4%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, \color{blue}{\frac{1}{x}}\right) \]
    4. Applied egg-rr5.4%

      \[\leadsto \color{blue}{\left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, \frac{1}{x}\right)} \]
    5. Step-by-step derivation
      1. fma-undefine17.6%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \color{blue}{\left(\left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} + \frac{1}{x}\right)} \]
      2. +-commutative17.6%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \color{blue}{\left(\frac{1}{x} + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1}\right)} \]
      3. associate-+r+17.6%

        \[\leadsto \color{blue}{\left(\left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \frac{1}{x}\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1}} \]
      4. associate-+r+17.6%

        \[\leadsto \color{blue}{\left(\frac{1}{1 + x} + \left(\frac{-1}{x} + \frac{1}{x}\right)\right)} + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      5. *-rgt-identity17.6%

        \[\leadsto \left(\frac{1}{1 + x} + \left(\color{blue}{\frac{-1}{x} \cdot 1} + \frac{1}{x}\right)\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      6. metadata-eval17.6%

        \[\leadsto \left(\frac{1}{1 + x} + \left(\frac{-1}{x} \cdot 1 + \frac{\color{blue}{-1 \cdot -1}}{x}\right)\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      7. associate-*l/17.6%

        \[\leadsto \left(\frac{1}{1 + x} + \left(\frac{-1}{x} \cdot 1 + \color{blue}{\frac{-1}{x} \cdot -1}\right)\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      8. distribute-lft-out17.6%

        \[\leadsto \left(\frac{1}{1 + x} + \color{blue}{\frac{-1}{x} \cdot \left(1 + -1\right)}\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      9. metadata-eval17.6%

        \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x} \cdot \color{blue}{0}\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      10. mul0-rgt17.6%

        \[\leadsto \left(\frac{1}{1 + x} + \color{blue}{0}\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
      11. +-rgt-identity17.6%

        \[\leadsto \color{blue}{\frac{1}{1 + x}} + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
    6. Simplified15.2%

      \[\leadsto \color{blue}{\frac{-1}{-1 - x} + \left(-{\left(\sqrt{x}\right)}^{-2}\right)} \]
    7. Taylor expanded in x around -inf 0.0%

      \[\leadsto \color{blue}{\frac{1 + \frac{1}{{\left(\sqrt{-1}\right)}^{2}}}{x}} \]
    8. Step-by-step derivation
      1. unpow20.0%

        \[\leadsto \frac{1 + \frac{1}{\color{blue}{\sqrt{-1} \cdot \sqrt{-1}}}}{x} \]
      2. rem-square-sqrt68.0%

        \[\leadsto \frac{1 + \frac{1}{\color{blue}{-1}}}{x} \]
      3. metadata-eval68.0%

        \[\leadsto \frac{1 + \color{blue}{-1}}{x} \]
      4. metadata-eval68.0%

        \[\leadsto \frac{\color{blue}{0}}{x} \]
      5. metadata-eval68.0%

        \[\leadsto \frac{\color{blue}{0 \cdot -1}}{x} \]
      6. associate-*r/68.0%

        \[\leadsto \color{blue}{0 \cdot \frac{-1}{x}} \]
      7. mul0-lft68.0%

        \[\leadsto \color{blue}{0} \]
    9. Simplified68.0%

      \[\leadsto \color{blue}{0} \]

    if -1 < x < 4.50000000000000021e102

    1. Initial program 83.9%

      \[\frac{1}{x + 1} - \frac{1}{x} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 80.6%

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

Alternative 5: 78.8% accurate, 0.8× speedup?

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

\\
\frac{x - \left(1 + x\right)}{x \cdot \left(1 + x\right)}
\end{array}
Derivation
  1. Initial program 78.1%

    \[\frac{1}{x + 1} - \frac{1}{x} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. clear-num78.1%

      \[\leadsto \color{blue}{\frac{1}{\frac{x + 1}{1}}} - \frac{1}{x} \]
    2. frac-sub78.9%

      \[\leadsto \color{blue}{\frac{1 \cdot x - \frac{x + 1}{1} \cdot 1}{\frac{x + 1}{1} \cdot x}} \]
    3. *-un-lft-identity78.9%

      \[\leadsto \frac{\color{blue}{x} - \frac{x + 1}{1} \cdot 1}{\frac{x + 1}{1} \cdot x} \]
    4. div-inv78.9%

      \[\leadsto \frac{x - \color{blue}{\left(\left(x + 1\right) \cdot \frac{1}{1}\right)} \cdot 1}{\frac{x + 1}{1} \cdot x} \]
    5. metadata-eval78.9%

      \[\leadsto \frac{x - \left(\left(x + 1\right) \cdot \color{blue}{1}\right) \cdot 1}{\frac{x + 1}{1} \cdot x} \]
    6. *-rgt-identity78.9%

      \[\leadsto \frac{x - \color{blue}{\left(x + 1\right)} \cdot 1}{\frac{x + 1}{1} \cdot x} \]
    7. *-rgt-identity78.9%

      \[\leadsto \frac{x - \color{blue}{\left(x + 1\right)}}{\frac{x + 1}{1} \cdot x} \]
    8. +-commutative78.9%

      \[\leadsto \frac{x - \color{blue}{\left(1 + x\right)}}{\frac{x + 1}{1} \cdot x} \]
    9. *-commutative78.9%

      \[\leadsto \frac{x - \left(1 + x\right)}{\color{blue}{x \cdot \frac{x + 1}{1}}} \]
    10. div-inv78.9%

      \[\leadsto \frac{x - \left(1 + x\right)}{x \cdot \color{blue}{\left(\left(x + 1\right) \cdot \frac{1}{1}\right)}} \]
    11. metadata-eval78.9%

      \[\leadsto \frac{x - \left(1 + x\right)}{x \cdot \left(\left(x + 1\right) \cdot \color{blue}{1}\right)} \]
    12. *-rgt-identity78.9%

      \[\leadsto \frac{x - \left(1 + x\right)}{x \cdot \color{blue}{\left(x + 1\right)}} \]
    13. +-commutative78.9%

      \[\leadsto \frac{x - \left(1 + x\right)}{x \cdot \color{blue}{\left(1 + x\right)}} \]
  4. Applied egg-rr78.9%

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

Alternative 6: 77.9% accurate, 1.0× speedup?

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

\\
\frac{1}{1 + x} - \frac{1}{x}
\end{array}
Derivation
  1. Initial program 78.1%

    \[\frac{1}{x + 1} - \frac{1}{x} \]
  2. Add Preprocessing
  3. Final simplification78.1%

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

Alternative 7: 27.0% accurate, 9.0× speedup?

\[\begin{array}{l} \\ 0 \end{array} \]
(FPCore (x) :precision binary64 0.0)
double code(double x) {
	return 0.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 0.0d0
end function
public static double code(double x) {
	return 0.0;
}
def code(x):
	return 0.0
function code(x)
	return 0.0
end
function tmp = code(x)
	tmp = 0.0;
end
code[x_] := 0.0
\begin{array}{l}

\\
0
\end{array}
Derivation
  1. Initial program 78.1%

    \[\frac{1}{x + 1} - \frac{1}{x} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. *-un-lft-identity78.1%

      \[\leadsto \color{blue}{1 \cdot \frac{1}{x + 1}} - \frac{1}{x} \]
    2. inv-pow78.1%

      \[\leadsto 1 \cdot \frac{1}{x + 1} - \color{blue}{{x}^{-1}} \]
    3. add-sqr-sqrt34.7%

      \[\leadsto 1 \cdot \frac{1}{x + 1} - {\color{blue}{\left(\sqrt{x} \cdot \sqrt{x}\right)}}^{-1} \]
    4. unpow-prod-down32.1%

      \[\leadsto 1 \cdot \frac{1}{x + 1} - \color{blue}{{\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}} \]
    5. prod-diff27.2%

      \[\leadsto \color{blue}{\mathsf{fma}\left(1, \frac{1}{x + 1}, -{\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right)} \]
    6. unpow-prod-down27.2%

      \[\leadsto \mathsf{fma}\left(1, \frac{1}{x + 1}, -\color{blue}{{\left(\sqrt{x} \cdot \sqrt{x}\right)}^{-1}}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
    7. add-sqr-sqrt27.3%

      \[\leadsto \mathsf{fma}\left(1, \frac{1}{x + 1}, -{\color{blue}{x}}^{-1}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
    8. inv-pow27.3%

      \[\leadsto \mathsf{fma}\left(1, \frac{1}{x + 1}, -\color{blue}{\frac{1}{x}}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
    9. fma-define27.3%

      \[\leadsto \color{blue}{\left(1 \cdot \frac{1}{x + 1} + \left(-\frac{1}{x}\right)\right)} + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
    10. *-un-lft-identity27.3%

      \[\leadsto \left(\color{blue}{\frac{1}{x + 1}} + \left(-\frac{1}{x}\right)\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
    11. +-commutative27.3%

      \[\leadsto \left(\frac{1}{\color{blue}{1 + x}} + \left(-\frac{1}{x}\right)\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
    12. distribute-neg-frac27.3%

      \[\leadsto \left(\frac{1}{1 + x} + \color{blue}{\frac{-1}{x}}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
    13. metadata-eval27.3%

      \[\leadsto \left(\frac{1}{1 + x} + \frac{\color{blue}{-1}}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1} \cdot {\left(\sqrt{x}\right)}^{-1}\right) \]
    14. unpow-prod-down27.2%

      \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, \color{blue}{{\left(\sqrt{x} \cdot \sqrt{x}\right)}^{-1}}\right) \]
    15. add-sqr-sqrt27.2%

      \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, {\color{blue}{x}}^{-1}\right) \]
    16. inv-pow27.2%

      \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, \color{blue}{\frac{1}{x}}\right) \]
  4. Applied egg-rr27.2%

    \[\leadsto \color{blue}{\left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \mathsf{fma}\left(-{\left(\sqrt{x}\right)}^{-1}, {\left(\sqrt{x}\right)}^{-1}, \frac{1}{x}\right)} \]
  5. Step-by-step derivation
    1. fma-undefine32.1%

      \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \color{blue}{\left(\left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} + \frac{1}{x}\right)} \]
    2. +-commutative32.1%

      \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \color{blue}{\left(\frac{1}{x} + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1}\right)} \]
    3. associate-+r+32.1%

      \[\leadsto \color{blue}{\left(\left(\frac{1}{1 + x} + \frac{-1}{x}\right) + \frac{1}{x}\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1}} \]
    4. associate-+r+32.1%

      \[\leadsto \color{blue}{\left(\frac{1}{1 + x} + \left(\frac{-1}{x} + \frac{1}{x}\right)\right)} + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
    5. *-rgt-identity32.1%

      \[\leadsto \left(\frac{1}{1 + x} + \left(\color{blue}{\frac{-1}{x} \cdot 1} + \frac{1}{x}\right)\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
    6. metadata-eval32.1%

      \[\leadsto \left(\frac{1}{1 + x} + \left(\frac{-1}{x} \cdot 1 + \frac{\color{blue}{-1 \cdot -1}}{x}\right)\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
    7. associate-*l/32.1%

      \[\leadsto \left(\frac{1}{1 + x} + \left(\frac{-1}{x} \cdot 1 + \color{blue}{\frac{-1}{x} \cdot -1}\right)\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
    8. distribute-lft-out32.1%

      \[\leadsto \left(\frac{1}{1 + x} + \color{blue}{\frac{-1}{x} \cdot \left(1 + -1\right)}\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
    9. metadata-eval32.1%

      \[\leadsto \left(\frac{1}{1 + x} + \frac{-1}{x} \cdot \color{blue}{0}\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
    10. mul0-rgt32.1%

      \[\leadsto \left(\frac{1}{1 + x} + \color{blue}{0}\right) + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
    11. +-rgt-identity32.1%

      \[\leadsto \color{blue}{\frac{1}{1 + x}} + \left(-{\left(\sqrt{x}\right)}^{-1}\right) \cdot {\left(\sqrt{x}\right)}^{-1} \]
  6. Simplified31.1%

    \[\leadsto \color{blue}{\frac{-1}{-1 - x} + \left(-{\left(\sqrt{x}\right)}^{-2}\right)} \]
  7. Taylor expanded in x around -inf 0.0%

    \[\leadsto \color{blue}{\frac{1 + \frac{1}{{\left(\sqrt{-1}\right)}^{2}}}{x}} \]
  8. Step-by-step derivation
    1. unpow20.0%

      \[\leadsto \frac{1 + \frac{1}{\color{blue}{\sqrt{-1} \cdot \sqrt{-1}}}}{x} \]
    2. rem-square-sqrt29.7%

      \[\leadsto \frac{1 + \frac{1}{\color{blue}{-1}}}{x} \]
    3. metadata-eval29.7%

      \[\leadsto \frac{1 + \color{blue}{-1}}{x} \]
    4. metadata-eval29.7%

      \[\leadsto \frac{\color{blue}{0}}{x} \]
    5. metadata-eval29.7%

      \[\leadsto \frac{\color{blue}{0 \cdot -1}}{x} \]
    6. associate-*r/29.7%

      \[\leadsto \color{blue}{0 \cdot \frac{-1}{x}} \]
    7. mul0-lft29.7%

      \[\leadsto \color{blue}{0} \]
  9. Simplified29.7%

    \[\leadsto \color{blue}{0} \]
  10. Add Preprocessing

Reproduce

?
herbie shell --seed 2024089 
(FPCore (x)
  :name "2frac (problem 3.3.1)"
  :precision binary64
  (- (/ 1.0 (+ x 1.0)) (/ 1.0 x)))