2isqrt (example 3.6)

Percentage Accurate: 38.1% → 98.7%
Time: 9.6s
Alternatives: 8
Speedup: 2.0×

Specification

?
\[x > 1 \land x < 10^{+308}\]
\[\begin{array}{l} \\ \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \end{array} \]
(FPCore (x) :precision binary64 (- (/ 1.0 (sqrt x)) (/ 1.0 (sqrt (+ x 1.0)))))
double code(double x) {
	return (1.0 / sqrt(x)) - (1.0 / sqrt((x + 1.0)));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (1.0d0 / sqrt(x)) - (1.0d0 / sqrt((x + 1.0d0)))
end function
public static double code(double x) {
	return (1.0 / Math.sqrt(x)) - (1.0 / Math.sqrt((x + 1.0)));
}
def code(x):
	return (1.0 / math.sqrt(x)) - (1.0 / math.sqrt((x + 1.0)))
function code(x)
	return Float64(Float64(1.0 / sqrt(x)) - Float64(1.0 / sqrt(Float64(x + 1.0))))
end
function tmp = code(x)
	tmp = (1.0 / sqrt(x)) - (1.0 / sqrt((x + 1.0)));
end
code[x_] := N[(N[(1.0 / N[Sqrt[x], $MachinePrecision]), $MachinePrecision] - N[(1.0 / N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

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

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 8 alternatives:

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

Initial Program: 38.1% accurate, 1.0× speedup?

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

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

Alternative 1: 98.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{{x}^{-0.5} \cdot 0.5 + \frac{-0.375}{{x}^{1.5}}}{x} \end{array} \]
(FPCore (x)
 :precision binary64
 (/ (+ (* (pow x -0.5) 0.5) (/ -0.375 (pow x 1.5))) x))
double code(double x) {
	return ((pow(x, -0.5) * 0.5) + (-0.375 / pow(x, 1.5))) / x;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (((x ** (-0.5d0)) * 0.5d0) + ((-0.375d0) / (x ** 1.5d0))) / x
end function
public static double code(double x) {
	return ((Math.pow(x, -0.5) * 0.5) + (-0.375 / Math.pow(x, 1.5))) / x;
}
def code(x):
	return ((math.pow(x, -0.5) * 0.5) + (-0.375 / math.pow(x, 1.5))) / x
function code(x)
	return Float64(Float64(Float64((x ^ -0.5) * 0.5) + Float64(-0.375 / (x ^ 1.5))) / x)
end
function tmp = code(x)
	tmp = (((x ^ -0.5) * 0.5) + (-0.375 / (x ^ 1.5))) / x;
end
code[x_] := N[(N[(N[(N[Power[x, -0.5], $MachinePrecision] * 0.5), $MachinePrecision] + N[(-0.375 / N[Power[x, 1.5], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]
\begin{array}{l}

\\
\frac{{x}^{-0.5} \cdot 0.5 + \frac{-0.375}{{x}^{1.5}}}{x}
\end{array}
Derivation
  1. Initial program 35.8%

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

    \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(\sqrt{\frac{1}{{x}^{3}}} \cdot \left(1 + \frac{1}{4} \cdot x\right)\right) - \left(\frac{-1}{2} \cdot \sqrt{x} + \frac{1}{2} \cdot \sqrt{\frac{1}{x}}\right)}{{x}^{2}}} \]
  4. Simplified84.1%

    \[\leadsto \color{blue}{\frac{\sqrt{\frac{1}{x \cdot \left(x \cdot x\right)}} \cdot \left(0.5 \cdot \left(1 + x \cdot 0.25\right)\right) + -0.5 \cdot \left(\sqrt{\frac{1}{x}} - \sqrt{x}\right)}{x \cdot x}} \]
  5. Taylor expanded in x around inf

    \[\leadsto \color{blue}{\frac{\frac{-1}{2} \cdot \sqrt{\frac{1}{{x}^{3}}} + \left(\frac{1}{8} \cdot \sqrt{\frac{1}{{x}^{3}}} + \frac{1}{2} \cdot \sqrt{\frac{1}{x}}\right)}{x}} \]
  6. Step-by-step derivation
    1. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\left(\frac{-1}{2} \cdot \sqrt{\frac{1}{{x}^{3}}} + \left(\frac{1}{8} \cdot \sqrt{\frac{1}{{x}^{3}}} + \frac{1}{2} \cdot \sqrt{\frac{1}{x}}\right)\right), \color{blue}{x}\right) \]
  7. Simplified98.8%

    \[\leadsto \color{blue}{\frac{0.5 \cdot \sqrt{\frac{1}{x}} + \sqrt{\frac{1}{x \cdot \left(x \cdot x\right)}} \cdot -0.375}{x}} \]
  8. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\left(\sqrt{\frac{1}{x}} \cdot \frac{1}{2}\right), \mathsf{*.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \frac{-3}{8}\right)\right), x\right) \]
    2. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\left(\sqrt{\frac{1}{x}}\right), \frac{1}{2}\right), \mathsf{*.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \frac{-3}{8}\right)\right), x\right) \]
    3. inv-powN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\left(\sqrt{{x}^{-1}}\right), \frac{1}{2}\right), \mathsf{*.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \frac{-3}{8}\right)\right), x\right) \]
    4. sqrt-pow1N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\left({x}^{\left(\frac{-1}{2}\right)}\right), \frac{1}{2}\right), \mathsf{*.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \frac{-3}{8}\right)\right), x\right) \]
    5. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\left({x}^{\frac{-1}{2}}\right), \frac{1}{2}\right), \mathsf{*.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \frac{-3}{8}\right)\right), x\right) \]
    6. pow-lowering-pow.f6498.8%

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{pow.f64}\left(x, \frac{-1}{2}\right), \frac{1}{2}\right), \mathsf{*.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \frac{-3}{8}\right)\right), x\right) \]
  9. Applied egg-rr98.8%

    \[\leadsto \frac{\color{blue}{{x}^{-0.5} \cdot 0.5} + \sqrt{\frac{1}{x \cdot \left(x \cdot x\right)}} \cdot -0.375}{x} \]
  10. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{pow.f64}\left(x, \frac{-1}{2}\right), \frac{1}{2}\right), \left(\frac{-3}{8} \cdot \sqrt{\frac{1}{x \cdot \left(x \cdot x\right)}}\right)\right), x\right) \]
    2. sqrt-divN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{pow.f64}\left(x, \frac{-1}{2}\right), \frac{1}{2}\right), \left(\frac{-3}{8} \cdot \frac{\sqrt{1}}{\sqrt{x \cdot \left(x \cdot x\right)}}\right)\right), x\right) \]
    3. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{pow.f64}\left(x, \frac{-1}{2}\right), \frac{1}{2}\right), \left(\frac{-3}{8} \cdot \frac{1}{\sqrt{x \cdot \left(x \cdot x\right)}}\right)\right), x\right) \]
    4. un-div-invN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{pow.f64}\left(x, \frac{-1}{2}\right), \frac{1}{2}\right), \left(\frac{\frac{-3}{8}}{\sqrt{x \cdot \left(x \cdot x\right)}}\right)\right), x\right) \]
    5. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{pow.f64}\left(x, \frac{-1}{2}\right), \frac{1}{2}\right), \mathsf{/.f64}\left(\frac{-3}{8}, \left(\sqrt{x \cdot \left(x \cdot x\right)}\right)\right)\right), x\right) \]
    6. cube-unmultN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{pow.f64}\left(x, \frac{-1}{2}\right), \frac{1}{2}\right), \mathsf{/.f64}\left(\frac{-3}{8}, \left(\sqrt{{x}^{3}}\right)\right)\right), x\right) \]
    7. sqrt-pow1N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{pow.f64}\left(x, \frac{-1}{2}\right), \frac{1}{2}\right), \mathsf{/.f64}\left(\frac{-3}{8}, \left({x}^{\left(\frac{3}{2}\right)}\right)\right)\right), x\right) \]
    8. pow-lowering-pow.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{pow.f64}\left(x, \frac{-1}{2}\right), \frac{1}{2}\right), \mathsf{/.f64}\left(\frac{-3}{8}, \mathsf{pow.f64}\left(x, \left(\frac{3}{2}\right)\right)\right)\right), x\right) \]
    9. metadata-eval98.8%

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{pow.f64}\left(x, \frac{-1}{2}\right), \frac{1}{2}\right), \mathsf{/.f64}\left(\frac{-3}{8}, \mathsf{pow.f64}\left(x, \frac{3}{2}\right)\right)\right), x\right) \]
  11. Applied egg-rr98.8%

    \[\leadsto \frac{{x}^{-0.5} \cdot 0.5 + \color{blue}{\frac{-0.375}{{x}^{1.5}}}}{x} \]
  12. Add Preprocessing

Alternative 2: 98.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{\frac{-0.375}{{x}^{1.5}} + \frac{0.5}{\sqrt{x}}}{x} \end{array} \]
(FPCore (x)
 :precision binary64
 (/ (+ (/ -0.375 (pow x 1.5)) (/ 0.5 (sqrt x))) x))
double code(double x) {
	return ((-0.375 / pow(x, 1.5)) + (0.5 / sqrt(x))) / x;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (((-0.375d0) / (x ** 1.5d0)) + (0.5d0 / sqrt(x))) / x
end function
public static double code(double x) {
	return ((-0.375 / Math.pow(x, 1.5)) + (0.5 / Math.sqrt(x))) / x;
}
def code(x):
	return ((-0.375 / math.pow(x, 1.5)) + (0.5 / math.sqrt(x))) / x
function code(x)
	return Float64(Float64(Float64(-0.375 / (x ^ 1.5)) + Float64(0.5 / sqrt(x))) / x)
end
function tmp = code(x)
	tmp = ((-0.375 / (x ^ 1.5)) + (0.5 / sqrt(x))) / x;
end
code[x_] := N[(N[(N[(-0.375 / N[Power[x, 1.5], $MachinePrecision]), $MachinePrecision] + N[(0.5 / N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{-0.375}{{x}^{1.5}} + \frac{0.5}{\sqrt{x}}}{x}
\end{array}
Derivation
  1. Initial program 35.8%

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

    \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(\sqrt{\frac{1}{{x}^{3}}} \cdot \left(1 + \frac{1}{4} \cdot x\right)\right) - \left(\frac{-1}{2} \cdot \sqrt{x} + \frac{1}{2} \cdot \sqrt{\frac{1}{x}}\right)}{{x}^{2}}} \]
  4. Simplified84.1%

    \[\leadsto \color{blue}{\frac{\sqrt{\frac{1}{x \cdot \left(x \cdot x\right)}} \cdot \left(0.5 \cdot \left(1 + x \cdot 0.25\right)\right) + -0.5 \cdot \left(\sqrt{\frac{1}{x}} - \sqrt{x}\right)}{x \cdot x}} \]
  5. Taylor expanded in x around inf

    \[\leadsto \color{blue}{\frac{\frac{-1}{2} \cdot \sqrt{\frac{1}{{x}^{3}}} + \left(\frac{1}{8} \cdot \sqrt{\frac{1}{{x}^{3}}} + \frac{1}{2} \cdot \sqrt{\frac{1}{x}}\right)}{x}} \]
  6. Step-by-step derivation
    1. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\left(\frac{-1}{2} \cdot \sqrt{\frac{1}{{x}^{3}}} + \left(\frac{1}{8} \cdot \sqrt{\frac{1}{{x}^{3}}} + \frac{1}{2} \cdot \sqrt{\frac{1}{x}}\right)\right), \color{blue}{x}\right) \]
  7. Simplified98.8%

    \[\leadsto \color{blue}{\frac{0.5 \cdot \sqrt{\frac{1}{x}} + \sqrt{\frac{1}{x \cdot \left(x \cdot x\right)}} \cdot -0.375}{x}} \]
  8. Step-by-step derivation
    1. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\left(\frac{1}{2} \cdot \sqrt{\frac{1}{x}} + \sqrt{\frac{1}{x \cdot \left(x \cdot x\right)}} \cdot \frac{-3}{8}\right), \color{blue}{x}\right) \]
    2. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\left(\frac{1}{2} \cdot \sqrt{\frac{1}{x}}\right), \left(\sqrt{\frac{1}{x \cdot \left(x \cdot x\right)}} \cdot \frac{-3}{8}\right)\right), x\right) \]
    3. sqrt-divN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\left(\frac{1}{2} \cdot \frac{\sqrt{1}}{\sqrt{x}}\right), \left(\sqrt{\frac{1}{x \cdot \left(x \cdot x\right)}} \cdot \frac{-3}{8}\right)\right), x\right) \]
    4. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\left(\frac{1}{2} \cdot \frac{1}{\sqrt{x}}\right), \left(\sqrt{\frac{1}{x \cdot \left(x \cdot x\right)}} \cdot \frac{-3}{8}\right)\right), x\right) \]
    5. un-div-invN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\left(\frac{\frac{1}{2}}{\sqrt{x}}\right), \left(\sqrt{\frac{1}{x \cdot \left(x \cdot x\right)}} \cdot \frac{-3}{8}\right)\right), x\right) \]
    6. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{1}{2}, \left(\sqrt{x}\right)\right), \left(\sqrt{\frac{1}{x \cdot \left(x \cdot x\right)}} \cdot \frac{-3}{8}\right)\right), x\right) \]
    7. sqrt-lowering-sqrt.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{1}{2}, \mathsf{sqrt.f64}\left(x\right)\right), \left(\sqrt{\frac{1}{x \cdot \left(x \cdot x\right)}} \cdot \frac{-3}{8}\right)\right), x\right) \]
    8. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{1}{2}, \mathsf{sqrt.f64}\left(x\right)\right), \left(\frac{-3}{8} \cdot \sqrt{\frac{1}{x \cdot \left(x \cdot x\right)}}\right)\right), x\right) \]
    9. sqrt-divN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{1}{2}, \mathsf{sqrt.f64}\left(x\right)\right), \left(\frac{-3}{8} \cdot \frac{\sqrt{1}}{\sqrt{x \cdot \left(x \cdot x\right)}}\right)\right), x\right) \]
    10. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{1}{2}, \mathsf{sqrt.f64}\left(x\right)\right), \left(\frac{-3}{8} \cdot \frac{1}{\sqrt{x \cdot \left(x \cdot x\right)}}\right)\right), x\right) \]
    11. un-div-invN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{1}{2}, \mathsf{sqrt.f64}\left(x\right)\right), \left(\frac{\frac{-3}{8}}{\sqrt{x \cdot \left(x \cdot x\right)}}\right)\right), x\right) \]
    12. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{1}{2}, \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-3}{8}, \left(\sqrt{x \cdot \left(x \cdot x\right)}\right)\right)\right), x\right) \]
    13. cube-unmultN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{1}{2}, \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-3}{8}, \left(\sqrt{{x}^{3}}\right)\right)\right), x\right) \]
    14. sqrt-pow1N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{1}{2}, \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-3}{8}, \left({x}^{\left(\frac{3}{2}\right)}\right)\right)\right), x\right) \]
    15. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{1}{2}, \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-3}{8}, \left({x}^{\frac{3}{2}}\right)\right)\right), x\right) \]
    16. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{1}{2}, \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-3}{8}, \left({x}^{\left(\frac{1}{2} \cdot 3\right)}\right)\right)\right), x\right) \]
    17. pow-lowering-pow.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{1}{2}, \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-3}{8}, \mathsf{pow.f64}\left(x, \left(\frac{1}{2} \cdot 3\right)\right)\right)\right), x\right) \]
    18. metadata-eval98.7%

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{1}{2}, \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-3}{8}, \mathsf{pow.f64}\left(x, \frac{3}{2}\right)\right)\right), x\right) \]
  9. Applied egg-rr98.7%

    \[\leadsto \color{blue}{\frac{\frac{0.5}{\sqrt{x}} + \frac{-0.375}{{x}^{1.5}}}{x}} \]
  10. Final simplification98.7%

    \[\leadsto \frac{\frac{-0.375}{{x}^{1.5}} + \frac{0.5}{\sqrt{x}}}{x} \]
  11. Add Preprocessing

Alternative 3: 97.7% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \frac{-0.5}{x} \cdot \left(\left(1 - x\right) \cdot {x}^{-1.5}\right) \end{array} \]
(FPCore (x) :precision binary64 (* (/ -0.5 x) (* (- 1.0 x) (pow x -1.5))))
double code(double x) {
	return (-0.5 / x) * ((1.0 - x) * pow(x, -1.5));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = ((-0.5d0) / x) * ((1.0d0 - x) * (x ** (-1.5d0)))
end function
public static double code(double x) {
	return (-0.5 / x) * ((1.0 - x) * Math.pow(x, -1.5));
}
def code(x):
	return (-0.5 / x) * ((1.0 - x) * math.pow(x, -1.5))
function code(x)
	return Float64(Float64(-0.5 / x) * Float64(Float64(1.0 - x) * (x ^ -1.5)))
end
function tmp = code(x)
	tmp = (-0.5 / x) * ((1.0 - x) * (x ^ -1.5));
end
code[x_] := N[(N[(-0.5 / x), $MachinePrecision] * N[(N[(1.0 - x), $MachinePrecision] * N[Power[x, -1.5], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-0.5}{x} \cdot \left(\left(1 - x\right) \cdot {x}^{-1.5}\right)
\end{array}
Derivation
  1. Initial program 35.8%

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

    \[\leadsto \color{blue}{\frac{\frac{-1}{2} \cdot \sqrt{\frac{1}{x}} - \frac{-1}{2} \cdot \sqrt{x}}{{x}^{2}}} \]
  4. Step-by-step derivation
    1. distribute-lft-out--N/A

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

      \[\leadsto \frac{\left(\sqrt{\frac{1}{x}} - \sqrt{x}\right) \cdot \frac{-1}{2}}{{\color{blue}{x}}^{2}} \]
    3. associate-/l*N/A

      \[\leadsto \left(\sqrt{\frac{1}{x}} - \sqrt{x}\right) \cdot \color{blue}{\frac{\frac{-1}{2}}{{x}^{2}}} \]
    4. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\left(\sqrt{\frac{1}{x}} - \sqrt{x}\right), \color{blue}{\left(\frac{\frac{-1}{2}}{{x}^{2}}\right)}\right) \]
    5. --lowering--.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\left(\sqrt{\frac{1}{x}}\right), \left(\sqrt{x}\right)\right), \left(\frac{\color{blue}{\frac{-1}{2}}}{{x}^{2}}\right)\right) \]
    6. sqrt-lowering-sqrt.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\left(\frac{1}{x}\right)\right), \left(\sqrt{x}\right)\right), \left(\frac{\frac{-1}{2}}{{x}^{2}}\right)\right) \]
    7. /-lowering-/.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \left(\sqrt{x}\right)\right), \left(\frac{\frac{-1}{2}}{{x}^{2}}\right)\right) \]
    8. sqrt-lowering-sqrt.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \mathsf{sqrt.f64}\left(x\right)\right), \left(\frac{\frac{-1}{2}}{{x}^{2}}\right)\right) \]
    9. /-lowering-/.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-1}{2}, \color{blue}{\left({x}^{2}\right)}\right)\right) \]
    10. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-1}{2}, \left(x \cdot \color{blue}{x}\right)\right)\right) \]
    11. *-lowering-*.f6483.2%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right) \]
  5. Simplified83.2%

    \[\leadsto \color{blue}{\left(\sqrt{\frac{1}{x}} - \sqrt{x}\right) \cdot \frac{-0.5}{x \cdot x}} \]
  6. Step-by-step derivation
    1. associate-*r/N/A

      \[\leadsto \frac{\left(\sqrt{\frac{1}{x}} - \sqrt{x}\right) \cdot \frac{-1}{2}}{\color{blue}{x \cdot x}} \]
    2. *-commutativeN/A

      \[\leadsto \frac{\frac{-1}{2} \cdot \left(\sqrt{\frac{1}{x}} - \sqrt{x}\right)}{\color{blue}{x} \cdot x} \]
    3. clear-numN/A

      \[\leadsto \frac{1}{\color{blue}{\frac{x \cdot x}{\frac{-1}{2} \cdot \left(\sqrt{\frac{1}{x}} - \sqrt{x}\right)}}} \]
    4. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \color{blue}{\left(\frac{x \cdot x}{\frac{-1}{2} \cdot \left(\sqrt{\frac{1}{x}} - \sqrt{x}\right)}\right)}\right) \]
    5. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\left(x \cdot x\right), \color{blue}{\left(\frac{-1}{2} \cdot \left(\sqrt{\frac{1}{x}} - \sqrt{x}\right)\right)}\right)\right) \]
    6. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\color{blue}{\frac{-1}{2}} \cdot \left(\sqrt{\frac{1}{x}} - \sqrt{x}\right)\right)\right)\right) \]
    7. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{*.f64}\left(\frac{-1}{2}, \color{blue}{\left(\sqrt{\frac{1}{x}} - \sqrt{x}\right)}\right)\right)\right) \]
    8. sqrt-divN/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{*.f64}\left(\frac{-1}{2}, \left(\frac{\sqrt{1}}{\sqrt{x}} - \sqrt{\color{blue}{x}}\right)\right)\right)\right) \]
    9. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{*.f64}\left(\frac{-1}{2}, \left(\frac{1}{\sqrt{x}} - \sqrt{x}\right)\right)\right)\right) \]
    10. /-rgt-identityN/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{*.f64}\left(\frac{-1}{2}, \left(\frac{1}{\sqrt{x}} - \frac{\sqrt{x}}{\color{blue}{1}}\right)\right)\right)\right) \]
    11. frac-subN/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{*.f64}\left(\frac{-1}{2}, \left(\frac{1 \cdot 1 - \sqrt{x} \cdot \sqrt{x}}{\color{blue}{\sqrt{x} \cdot 1}}\right)\right)\right)\right) \]
    12. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{*.f64}\left(\frac{-1}{2}, \left(\frac{1 - \sqrt{x} \cdot \sqrt{x}}{\sqrt{\color{blue}{x}} \cdot 1}\right)\right)\right)\right) \]
    13. rem-square-sqrtN/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{*.f64}\left(\frac{-1}{2}, \left(\frac{1 - x}{\sqrt{x} \cdot 1}\right)\right)\right)\right) \]
    14. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{*.f64}\left(\frac{-1}{2}, \left(\frac{1 - x}{\sqrt{x} \cdot \frac{1}{\color{blue}{1}}}\right)\right)\right)\right) \]
    15. div-invN/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{*.f64}\left(\frac{-1}{2}, \left(\frac{1 - x}{\frac{\sqrt{x}}{\color{blue}{1}}}\right)\right)\right)\right) \]
    16. /-rgt-identityN/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{*.f64}\left(\frac{-1}{2}, \left(\frac{1 - x}{\sqrt{x}}\right)\right)\right)\right) \]
    17. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{*.f64}\left(\frac{-1}{2}, \mathsf{/.f64}\left(\left(1 - x\right), \color{blue}{\left(\sqrt{x}\right)}\right)\right)\right)\right) \]
    18. --lowering--.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{*.f64}\left(\frac{-1}{2}, \mathsf{/.f64}\left(\mathsf{\_.f64}\left(1, x\right), \left(\sqrt{\color{blue}{x}}\right)\right)\right)\right)\right) \]
    19. sqrt-lowering-sqrt.f6483.2%

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{*.f64}\left(\frac{-1}{2}, \mathsf{/.f64}\left(\mathsf{\_.f64}\left(1, x\right), \mathsf{sqrt.f64}\left(x\right)\right)\right)\right)\right) \]
  7. Applied egg-rr83.2%

    \[\leadsto \color{blue}{\frac{1}{\frac{x \cdot x}{-0.5 \cdot \frac{1 - x}{\sqrt{x}}}}} \]
  8. Step-by-step derivation
    1. inv-powN/A

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

      \[\leadsto {\left(\frac{x}{\frac{-1}{2}} \cdot \frac{x}{\frac{1 - x}{\sqrt{x}}}\right)}^{-1} \]
    3. unpow-prod-downN/A

      \[\leadsto {\left(\frac{x}{\frac{-1}{2}}\right)}^{-1} \cdot \color{blue}{{\left(\frac{x}{\frac{1 - x}{\sqrt{x}}}\right)}^{-1}} \]
    4. inv-powN/A

      \[\leadsto \frac{1}{\frac{x}{\frac{-1}{2}}} \cdot {\color{blue}{\left(\frac{x}{\frac{1 - x}{\sqrt{x}}}\right)}}^{-1} \]
    5. clear-numN/A

      \[\leadsto \frac{\frac{-1}{2}}{x} \cdot {\color{blue}{\left(\frac{x}{\frac{1 - x}{\sqrt{x}}}\right)}}^{-1} \]
    6. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\left(\frac{\frac{-1}{2}}{x}\right), \color{blue}{\left({\left(\frac{x}{\frac{1 - x}{\sqrt{x}}}\right)}^{-1}\right)}\right) \]
    7. /-lowering-/.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left({\color{blue}{\left(\frac{x}{\frac{1 - x}{\sqrt{x}}}\right)}}^{-1}\right)\right) \]
    8. div-invN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left({\left(x \cdot \frac{1}{\frac{1 - x}{\sqrt{x}}}\right)}^{-1}\right)\right) \]
    9. clear-numN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left({\left(x \cdot \frac{\sqrt{x}}{1 - x}\right)}^{-1}\right)\right) \]
    10. unpow-prod-downN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left({x}^{-1} \cdot \color{blue}{{\left(\frac{\sqrt{x}}{1 - x}\right)}^{-1}}\right)\right) \]
    11. inv-powN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\frac{1}{x} \cdot {\color{blue}{\left(\frac{\sqrt{x}}{1 - x}\right)}}^{-1}\right)\right) \]
    12. inv-powN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\frac{1}{x} \cdot \frac{1}{\color{blue}{\frac{\sqrt{x}}{1 - x}}}\right)\right) \]
    13. clear-numN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\frac{1}{x} \cdot \frac{1 - x}{\color{blue}{\sqrt{x}}}\right)\right) \]
    14. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(\left(\frac{1}{x}\right), \color{blue}{\left(\frac{1 - x}{\sqrt{x}}\right)}\right)\right) \]
    15. /-lowering-/.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(\mathsf{/.f64}\left(1, x\right), \left(\frac{\color{blue}{1 - x}}{\sqrt{x}}\right)\right)\right) \]
    16. /-lowering-/.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(\left(1 - x\right), \color{blue}{\left(\sqrt{x}\right)}\right)\right)\right) \]
    17. --lowering--.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(\mathsf{\_.f64}\left(1, x\right), \left(\sqrt{\color{blue}{x}}\right)\right)\right)\right) \]
    18. sqrt-lowering-sqrt.f6497.7%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(\mathsf{\_.f64}\left(1, x\right), \mathsf{sqrt.f64}\left(x\right)\right)\right)\right) \]
  9. Applied egg-rr97.7%

    \[\leadsto \color{blue}{\frac{-0.5}{x} \cdot \left(\frac{1}{x} \cdot \frac{1 - x}{\sqrt{x}}\right)} \]
  10. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\frac{1 - x}{\sqrt{x}} \cdot \color{blue}{\frac{1}{x}}\right)\right) \]
    2. clear-numN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\frac{1}{\frac{\sqrt{x}}{1 - x}} \cdot \frac{\color{blue}{1}}{x}\right)\right) \]
    3. associate-/r/N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\left(\frac{1}{\sqrt{x}} \cdot \left(1 - x\right)\right) \cdot \frac{\color{blue}{1}}{x}\right)\right) \]
    4. pow1/2N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\left(\frac{1}{{x}^{\frac{1}{2}}} \cdot \left(1 - x\right)\right) \cdot \frac{1}{x}\right)\right) \]
    5. pow-flipN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\left({x}^{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)} \cdot \left(1 - x\right)\right) \cdot \frac{1}{x}\right)\right) \]
    6. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\left({x}^{\frac{-1}{2}} \cdot \left(1 - x\right)\right) \cdot \frac{1}{x}\right)\right) \]
    7. *-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\left(\left(1 - x\right) \cdot {x}^{\frac{-1}{2}}\right) \cdot \frac{\color{blue}{1}}{x}\right)\right) \]
    8. associate-*l*N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\left(1 - x\right) \cdot \color{blue}{\left({x}^{\frac{-1}{2}} \cdot \frac{1}{x}\right)}\right)\right) \]
    9. inv-powN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\left(1 - x\right) \cdot \left({x}^{\frac{-1}{2}} \cdot {x}^{\color{blue}{-1}}\right)\right)\right) \]
    10. pow-prod-upN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\left(1 - x\right) \cdot {x}^{\color{blue}{\left(\frac{-1}{2} + -1\right)}}\right)\right) \]
    11. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\left(1 - x\right) \cdot {x}^{\frac{-3}{2}}\right)\right) \]
    12. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\left(1 - x\right) \cdot {x}^{\left(3 \cdot \color{blue}{\frac{-1}{2}}\right)}\right)\right) \]
    13. pow-powN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\left(1 - x\right) \cdot {\left({x}^{3}\right)}^{\color{blue}{\frac{-1}{2}}}\right)\right) \]
    14. cube-unmultN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\left(1 - x\right) \cdot {\left(x \cdot \left(x \cdot x\right)\right)}^{\frac{-1}{2}}\right)\right) \]
    15. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\left(1 - x\right) \cdot {\left(x \cdot \left(x \cdot x\right)\right)}^{\left(\frac{-1}{\color{blue}{2}}\right)}\right)\right) \]
    16. sqrt-pow1N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\left(1 - x\right) \cdot \sqrt{{\left(x \cdot \left(x \cdot x\right)\right)}^{-1}}\right)\right) \]
    17. inv-powN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(\left(1 - x\right) \cdot \sqrt{\frac{1}{x \cdot \left(x \cdot x\right)}}\right)\right) \]
    18. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(\left(1 - x\right), \color{blue}{\left(\sqrt{\frac{1}{x \cdot \left(x \cdot x\right)}}\right)}\right)\right) \]
    19. --lowering--.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(\mathsf{\_.f64}\left(1, x\right), \left(\sqrt{\color{blue}{\frac{1}{x \cdot \left(x \cdot x\right)}}}\right)\right)\right) \]
    20. inv-powN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(\mathsf{\_.f64}\left(1, x\right), \left(\sqrt{{\left(x \cdot \left(x \cdot x\right)\right)}^{-1}}\right)\right)\right) \]
    21. sqrt-pow1N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(\mathsf{\_.f64}\left(1, x\right), \left({\left(x \cdot \left(x \cdot x\right)\right)}^{\color{blue}{\left(\frac{-1}{2}\right)}}\right)\right)\right) \]
    22. cube-unmultN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(\mathsf{\_.f64}\left(1, x\right), \left({\left({x}^{3}\right)}^{\left(\frac{\color{blue}{-1}}{2}\right)}\right)\right)\right) \]
    23. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(\mathsf{\_.f64}\left(1, x\right), \left({\left({x}^{3}\right)}^{\frac{-1}{2}}\right)\right)\right) \]
  11. Applied egg-rr98.1%

    \[\leadsto \frac{-0.5}{x} \cdot \color{blue}{\left(\left(1 - x\right) \cdot {x}^{-1.5}\right)} \]
  12. Add Preprocessing

Alternative 4: 97.5% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \frac{-0.5}{x} \cdot \left(\frac{0}{x} - {x}^{-0.5}\right) \end{array} \]
(FPCore (x) :precision binary64 (* (/ -0.5 x) (- (/ 0.0 x) (pow x -0.5))))
double code(double x) {
	return (-0.5 / x) * ((0.0 / x) - pow(x, -0.5));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = ((-0.5d0) / x) * ((0.0d0 / x) - (x ** (-0.5d0)))
end function
public static double code(double x) {
	return (-0.5 / x) * ((0.0 / x) - Math.pow(x, -0.5));
}
def code(x):
	return (-0.5 / x) * ((0.0 / x) - math.pow(x, -0.5))
function code(x)
	return Float64(Float64(-0.5 / x) * Float64(Float64(0.0 / x) - (x ^ -0.5)))
end
function tmp = code(x)
	tmp = (-0.5 / x) * ((0.0 / x) - (x ^ -0.5));
end
code[x_] := N[(N[(-0.5 / x), $MachinePrecision] * N[(N[(0.0 / x), $MachinePrecision] - N[Power[x, -0.5], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-0.5}{x} \cdot \left(\frac{0}{x} - {x}^{-0.5}\right)
\end{array}
Derivation
  1. Initial program 35.8%

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

    \[\leadsto \color{blue}{\frac{\frac{-1}{2} \cdot \sqrt{\frac{1}{x}} - \frac{-1}{2} \cdot \sqrt{x}}{{x}^{2}}} \]
  4. Step-by-step derivation
    1. distribute-lft-out--N/A

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

      \[\leadsto \frac{\left(\sqrt{\frac{1}{x}} - \sqrt{x}\right) \cdot \frac{-1}{2}}{{\color{blue}{x}}^{2}} \]
    3. associate-/l*N/A

      \[\leadsto \left(\sqrt{\frac{1}{x}} - \sqrt{x}\right) \cdot \color{blue}{\frac{\frac{-1}{2}}{{x}^{2}}} \]
    4. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\left(\sqrt{\frac{1}{x}} - \sqrt{x}\right), \color{blue}{\left(\frac{\frac{-1}{2}}{{x}^{2}}\right)}\right) \]
    5. --lowering--.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\left(\sqrt{\frac{1}{x}}\right), \left(\sqrt{x}\right)\right), \left(\frac{\color{blue}{\frac{-1}{2}}}{{x}^{2}}\right)\right) \]
    6. sqrt-lowering-sqrt.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\left(\frac{1}{x}\right)\right), \left(\sqrt{x}\right)\right), \left(\frac{\frac{-1}{2}}{{x}^{2}}\right)\right) \]
    7. /-lowering-/.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \left(\sqrt{x}\right)\right), \left(\frac{\frac{-1}{2}}{{x}^{2}}\right)\right) \]
    8. sqrt-lowering-sqrt.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \mathsf{sqrt.f64}\left(x\right)\right), \left(\frac{\frac{-1}{2}}{{x}^{2}}\right)\right) \]
    9. /-lowering-/.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-1}{2}, \color{blue}{\left({x}^{2}\right)}\right)\right) \]
    10. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-1}{2}, \left(x \cdot \color{blue}{x}\right)\right)\right) \]
    11. *-lowering-*.f6483.2%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right) \]
  5. Simplified83.2%

    \[\leadsto \color{blue}{\left(\sqrt{\frac{1}{x}} - \sqrt{x}\right) \cdot \frac{-0.5}{x \cdot x}} \]
  6. Taylor expanded in x around inf

    \[\leadsto \mathsf{*.f64}\left(\color{blue}{\left(-1 \cdot \sqrt{x}\right)}, \mathsf{/.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(x, x\right)\right)\right) \]
  7. Step-by-step derivation
    1. mul-1-negN/A

      \[\leadsto \mathsf{*.f64}\left(\left(\mathsf{neg}\left(\sqrt{x}\right)\right), \mathsf{/.f64}\left(\color{blue}{\frac{-1}{2}}, \mathsf{*.f64}\left(x, x\right)\right)\right) \]
    2. neg-sub0N/A

      \[\leadsto \mathsf{*.f64}\left(\left(0 - \sqrt{x}\right), \mathsf{/.f64}\left(\color{blue}{\frac{-1}{2}}, \mathsf{*.f64}\left(x, x\right)\right)\right) \]
    3. --lowering--.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(0, \left(\sqrt{x}\right)\right), \mathsf{/.f64}\left(\color{blue}{\frac{-1}{2}}, \mathsf{*.f64}\left(x, x\right)\right)\right) \]
    4. sqrt-lowering-sqrt.f6483.1%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(0, \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(x, x\right)\right)\right) \]
  8. Simplified83.1%

    \[\leadsto \color{blue}{\left(0 - \sqrt{x}\right)} \cdot \frac{-0.5}{x \cdot x} \]
  9. Step-by-step derivation
    1. sub0-negN/A

      \[\leadsto \left(\mathsf{neg}\left(\sqrt{x}\right)\right) \cdot \frac{\color{blue}{\frac{-1}{2}}}{x \cdot x} \]
    2. associate-*r/N/A

      \[\leadsto \frac{\left(\mathsf{neg}\left(\sqrt{x}\right)\right) \cdot \frac{-1}{2}}{\color{blue}{x \cdot x}} \]
    3. times-fracN/A

      \[\leadsto \frac{\mathsf{neg}\left(\sqrt{x}\right)}{x} \cdot \color{blue}{\frac{\frac{-1}{2}}{x}} \]
    4. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\left(\frac{\mathsf{neg}\left(\sqrt{x}\right)}{x}\right), \color{blue}{\left(\frac{\frac{-1}{2}}{x}\right)}\right) \]
  10. Applied egg-rr97.9%

    \[\leadsto \color{blue}{\left(\frac{0}{x} - {x}^{-0.5}\right) \cdot \frac{-0.5}{x}} \]
  11. Final simplification97.9%

    \[\leadsto \frac{-0.5}{x} \cdot \left(\frac{0}{x} - {x}^{-0.5}\right) \]
  12. Add Preprocessing

Alternative 5: 97.6% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \frac{\frac{-0.5 \cdot \sqrt{x}}{x}}{0 - x} \end{array} \]
(FPCore (x) :precision binary64 (/ (/ (* -0.5 (sqrt x)) x) (- 0.0 x)))
double code(double x) {
	return ((-0.5 * sqrt(x)) / x) / (0.0 - x);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (((-0.5d0) * sqrt(x)) / x) / (0.0d0 - x)
end function
public static double code(double x) {
	return ((-0.5 * Math.sqrt(x)) / x) / (0.0 - x);
}
def code(x):
	return ((-0.5 * math.sqrt(x)) / x) / (0.0 - x)
function code(x)
	return Float64(Float64(Float64(-0.5 * sqrt(x)) / x) / Float64(0.0 - x))
end
function tmp = code(x)
	tmp = ((-0.5 * sqrt(x)) / x) / (0.0 - x);
end
code[x_] := N[(N[(N[(-0.5 * N[Sqrt[x], $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision] / N[(0.0 - x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{-0.5 \cdot \sqrt{x}}{x}}{0 - x}
\end{array}
Derivation
  1. Initial program 35.8%

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

    \[\leadsto \color{blue}{\frac{\frac{-1}{2} \cdot \sqrt{\frac{1}{x}} - \frac{-1}{2} \cdot \sqrt{x}}{{x}^{2}}} \]
  4. Step-by-step derivation
    1. distribute-lft-out--N/A

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

      \[\leadsto \frac{\left(\sqrt{\frac{1}{x}} - \sqrt{x}\right) \cdot \frac{-1}{2}}{{\color{blue}{x}}^{2}} \]
    3. associate-/l*N/A

      \[\leadsto \left(\sqrt{\frac{1}{x}} - \sqrt{x}\right) \cdot \color{blue}{\frac{\frac{-1}{2}}{{x}^{2}}} \]
    4. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\left(\sqrt{\frac{1}{x}} - \sqrt{x}\right), \color{blue}{\left(\frac{\frac{-1}{2}}{{x}^{2}}\right)}\right) \]
    5. --lowering--.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\left(\sqrt{\frac{1}{x}}\right), \left(\sqrt{x}\right)\right), \left(\frac{\color{blue}{\frac{-1}{2}}}{{x}^{2}}\right)\right) \]
    6. sqrt-lowering-sqrt.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\left(\frac{1}{x}\right)\right), \left(\sqrt{x}\right)\right), \left(\frac{\frac{-1}{2}}{{x}^{2}}\right)\right) \]
    7. /-lowering-/.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \left(\sqrt{x}\right)\right), \left(\frac{\frac{-1}{2}}{{x}^{2}}\right)\right) \]
    8. sqrt-lowering-sqrt.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \mathsf{sqrt.f64}\left(x\right)\right), \left(\frac{\frac{-1}{2}}{{x}^{2}}\right)\right) \]
    9. /-lowering-/.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-1}{2}, \color{blue}{\left({x}^{2}\right)}\right)\right) \]
    10. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-1}{2}, \left(x \cdot \color{blue}{x}\right)\right)\right) \]
    11. *-lowering-*.f6483.2%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right) \]
  5. Simplified83.2%

    \[\leadsto \color{blue}{\left(\sqrt{\frac{1}{x}} - \sqrt{x}\right) \cdot \frac{-0.5}{x \cdot x}} \]
  6. Taylor expanded in x around inf

    \[\leadsto \mathsf{*.f64}\left(\color{blue}{\left(-1 \cdot \sqrt{x}\right)}, \mathsf{/.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(x, x\right)\right)\right) \]
  7. Step-by-step derivation
    1. mul-1-negN/A

      \[\leadsto \mathsf{*.f64}\left(\left(\mathsf{neg}\left(\sqrt{x}\right)\right), \mathsf{/.f64}\left(\color{blue}{\frac{-1}{2}}, \mathsf{*.f64}\left(x, x\right)\right)\right) \]
    2. neg-sub0N/A

      \[\leadsto \mathsf{*.f64}\left(\left(0 - \sqrt{x}\right), \mathsf{/.f64}\left(\color{blue}{\frac{-1}{2}}, \mathsf{*.f64}\left(x, x\right)\right)\right) \]
    3. --lowering--.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(0, \left(\sqrt{x}\right)\right), \mathsf{/.f64}\left(\color{blue}{\frac{-1}{2}}, \mathsf{*.f64}\left(x, x\right)\right)\right) \]
    4. sqrt-lowering-sqrt.f6483.1%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(0, \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(x, x\right)\right)\right) \]
  8. Simplified83.1%

    \[\leadsto \color{blue}{\left(0 - \sqrt{x}\right)} \cdot \frac{-0.5}{x \cdot x} \]
  9. Step-by-step derivation
    1. sub0-negN/A

      \[\leadsto \left(\mathsf{neg}\left(\sqrt{x}\right)\right) \cdot \frac{\color{blue}{\frac{-1}{2}}}{x \cdot x} \]
    2. associate-*r/N/A

      \[\leadsto \frac{\left(\mathsf{neg}\left(\sqrt{x}\right)\right) \cdot \frac{-1}{2}}{\color{blue}{x \cdot x}} \]
    3. associate-/r*N/A

      \[\leadsto \frac{\frac{\left(\mathsf{neg}\left(\sqrt{x}\right)\right) \cdot \frac{-1}{2}}{x}}{\color{blue}{x}} \]
    4. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\left(\frac{\left(\mathsf{neg}\left(\sqrt{x}\right)\right) \cdot \frac{-1}{2}}{x}\right), \color{blue}{x}\right) \]
    5. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{/.f64}\left(\left(\left(\mathsf{neg}\left(\sqrt{x}\right)\right) \cdot \frac{-1}{2}\right), x\right), x\right) \]
    6. distribute-lft-neg-outN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{/.f64}\left(\left(\mathsf{neg}\left(\sqrt{x} \cdot \frac{-1}{2}\right)\right), x\right), x\right) \]
    7. neg-lowering-neg.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{/.f64}\left(\mathsf{neg.f64}\left(\left(\sqrt{x} \cdot \frac{-1}{2}\right)\right), x\right), x\right) \]
    8. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{/.f64}\left(\mathsf{neg.f64}\left(\mathsf{*.f64}\left(\left(\sqrt{x}\right), \frac{-1}{2}\right)\right), x\right), x\right) \]
    9. sqrt-lowering-sqrt.f6497.9%

      \[\leadsto \mathsf{/.f64}\left(\mathsf{/.f64}\left(\mathsf{neg.f64}\left(\mathsf{*.f64}\left(\mathsf{sqrt.f64}\left(x\right), \frac{-1}{2}\right)\right), x\right), x\right) \]
  10. Applied egg-rr97.9%

    \[\leadsto \color{blue}{\frac{\frac{-\sqrt{x} \cdot -0.5}{x}}{x}} \]
  11. Final simplification97.9%

    \[\leadsto \frac{\frac{-0.5 \cdot \sqrt{x}}{x}}{0 - x} \]
  12. Add Preprocessing

Alternative 6: 97.6% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \frac{0.5 \cdot \sqrt{\frac{1}{x}}}{x} \end{array} \]
(FPCore (x) :precision binary64 (/ (* 0.5 (sqrt (/ 1.0 x))) x))
double code(double x) {
	return (0.5 * sqrt((1.0 / x))) / x;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (0.5d0 * sqrt((1.0d0 / x))) / x
end function
public static double code(double x) {
	return (0.5 * Math.sqrt((1.0 / x))) / x;
}
def code(x):
	return (0.5 * math.sqrt((1.0 / x))) / x
function code(x)
	return Float64(Float64(0.5 * sqrt(Float64(1.0 / x))) / x)
end
function tmp = code(x)
	tmp = (0.5 * sqrt((1.0 / x))) / x;
end
code[x_] := N[(N[(0.5 * N[Sqrt[N[(1.0 / x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]
\begin{array}{l}

\\
\frac{0.5 \cdot \sqrt{\frac{1}{x}}}{x}
\end{array}
Derivation
  1. Initial program 35.8%

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

    \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(\sqrt{\frac{1}{{x}^{3}}} \cdot \left(1 + \frac{1}{4} \cdot x\right)\right) - \left(\frac{-1}{2} \cdot \sqrt{x} + \frac{1}{2} \cdot \sqrt{\frac{1}{x}}\right)}{{x}^{2}}} \]
  4. Simplified84.1%

    \[\leadsto \color{blue}{\frac{\sqrt{\frac{1}{x \cdot \left(x \cdot x\right)}} \cdot \left(0.5 \cdot \left(1 + x \cdot 0.25\right)\right) + -0.5 \cdot \left(\sqrt{\frac{1}{x}} - \sqrt{x}\right)}{x \cdot x}} \]
  5. Taylor expanded in x around inf

    \[\leadsto \color{blue}{\frac{\frac{-1}{2} \cdot \sqrt{\frac{1}{{x}^{3}}} + \left(\frac{1}{8} \cdot \sqrt{\frac{1}{{x}^{3}}} + \frac{1}{2} \cdot \sqrt{\frac{1}{x}}\right)}{x}} \]
  6. Step-by-step derivation
    1. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\left(\frac{-1}{2} \cdot \sqrt{\frac{1}{{x}^{3}}} + \left(\frac{1}{8} \cdot \sqrt{\frac{1}{{x}^{3}}} + \frac{1}{2} \cdot \sqrt{\frac{1}{x}}\right)\right), \color{blue}{x}\right) \]
  7. Simplified98.8%

    \[\leadsto \color{blue}{\frac{0.5 \cdot \sqrt{\frac{1}{x}} + \sqrt{\frac{1}{x \cdot \left(x \cdot x\right)}} \cdot -0.375}{x}} \]
  8. Taylor expanded in x around inf

    \[\leadsto \mathsf{/.f64}\left(\color{blue}{\left(\frac{1}{2} \cdot \sqrt{\frac{1}{x}}\right)}, x\right) \]
  9. Step-by-step derivation
    1. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(\frac{1}{2}, \left(\sqrt{\frac{1}{x}}\right)\right), x\right) \]
    2. sqrt-lowering-sqrt.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(\frac{1}{2}, \mathsf{sqrt.f64}\left(\left(\frac{1}{x}\right)\right)\right), x\right) \]
    3. /-lowering-/.f6497.9%

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(\frac{1}{2}, \mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right)\right), x\right) \]
  10. Simplified97.9%

    \[\leadsto \frac{\color{blue}{0.5 \cdot \sqrt{\frac{1}{x}}}}{x} \]
  11. Add Preprocessing

Alternative 7: 97.5% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \frac{\sqrt{x}}{x} \cdot \frac{0.5}{x} \end{array} \]
(FPCore (x) :precision binary64 (* (/ (sqrt x) x) (/ 0.5 x)))
double code(double x) {
	return (sqrt(x) / x) * (0.5 / x);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (sqrt(x) / x) * (0.5d0 / x)
end function
public static double code(double x) {
	return (Math.sqrt(x) / x) * (0.5 / x);
}
def code(x):
	return (math.sqrt(x) / x) * (0.5 / x)
function code(x)
	return Float64(Float64(sqrt(x) / x) * Float64(0.5 / x))
end
function tmp = code(x)
	tmp = (sqrt(x) / x) * (0.5 / x);
end
code[x_] := N[(N[(N[Sqrt[x], $MachinePrecision] / x), $MachinePrecision] * N[(0.5 / x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\sqrt{x}}{x} \cdot \frac{0.5}{x}
\end{array}
Derivation
  1. Initial program 35.8%

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

    \[\leadsto \color{blue}{\frac{\frac{-1}{2} \cdot \sqrt{\frac{1}{x}} - \frac{-1}{2} \cdot \sqrt{x}}{{x}^{2}}} \]
  4. Step-by-step derivation
    1. distribute-lft-out--N/A

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

      \[\leadsto \frac{\left(\sqrt{\frac{1}{x}} - \sqrt{x}\right) \cdot \frac{-1}{2}}{{\color{blue}{x}}^{2}} \]
    3. associate-/l*N/A

      \[\leadsto \left(\sqrt{\frac{1}{x}} - \sqrt{x}\right) \cdot \color{blue}{\frac{\frac{-1}{2}}{{x}^{2}}} \]
    4. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\left(\sqrt{\frac{1}{x}} - \sqrt{x}\right), \color{blue}{\left(\frac{\frac{-1}{2}}{{x}^{2}}\right)}\right) \]
    5. --lowering--.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\left(\sqrt{\frac{1}{x}}\right), \left(\sqrt{x}\right)\right), \left(\frac{\color{blue}{\frac{-1}{2}}}{{x}^{2}}\right)\right) \]
    6. sqrt-lowering-sqrt.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\left(\frac{1}{x}\right)\right), \left(\sqrt{x}\right)\right), \left(\frac{\frac{-1}{2}}{{x}^{2}}\right)\right) \]
    7. /-lowering-/.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \left(\sqrt{x}\right)\right), \left(\frac{\frac{-1}{2}}{{x}^{2}}\right)\right) \]
    8. sqrt-lowering-sqrt.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \mathsf{sqrt.f64}\left(x\right)\right), \left(\frac{\frac{-1}{2}}{{x}^{2}}\right)\right) \]
    9. /-lowering-/.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-1}{2}, \color{blue}{\left({x}^{2}\right)}\right)\right) \]
    10. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-1}{2}, \left(x \cdot \color{blue}{x}\right)\right)\right) \]
    11. *-lowering-*.f6483.2%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right), \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right) \]
  5. Simplified83.2%

    \[\leadsto \color{blue}{\left(\sqrt{\frac{1}{x}} - \sqrt{x}\right) \cdot \frac{-0.5}{x \cdot x}} \]
  6. Taylor expanded in x around inf

    \[\leadsto \mathsf{*.f64}\left(\color{blue}{\left(-1 \cdot \sqrt{x}\right)}, \mathsf{/.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(x, x\right)\right)\right) \]
  7. Step-by-step derivation
    1. mul-1-negN/A

      \[\leadsto \mathsf{*.f64}\left(\left(\mathsf{neg}\left(\sqrt{x}\right)\right), \mathsf{/.f64}\left(\color{blue}{\frac{-1}{2}}, \mathsf{*.f64}\left(x, x\right)\right)\right) \]
    2. neg-sub0N/A

      \[\leadsto \mathsf{*.f64}\left(\left(0 - \sqrt{x}\right), \mathsf{/.f64}\left(\color{blue}{\frac{-1}{2}}, \mathsf{*.f64}\left(x, x\right)\right)\right) \]
    3. --lowering--.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(0, \left(\sqrt{x}\right)\right), \mathsf{/.f64}\left(\color{blue}{\frac{-1}{2}}, \mathsf{*.f64}\left(x, x\right)\right)\right) \]
    4. sqrt-lowering-sqrt.f6483.1%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{\_.f64}\left(0, \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{/.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(x, x\right)\right)\right) \]
  8. Simplified83.1%

    \[\leadsto \color{blue}{\left(0 - \sqrt{x}\right)} \cdot \frac{-0.5}{x \cdot x} \]
  9. Step-by-step derivation
    1. sub0-negN/A

      \[\leadsto \left(\mathsf{neg}\left(\sqrt{x}\right)\right) \cdot \frac{\color{blue}{\frac{-1}{2}}}{x \cdot x} \]
    2. associate-*r/N/A

      \[\leadsto \frac{\left(\mathsf{neg}\left(\sqrt{x}\right)\right) \cdot \frac{-1}{2}}{\color{blue}{x \cdot x}} \]
    3. associate-/r*N/A

      \[\leadsto \frac{\frac{\left(\mathsf{neg}\left(\sqrt{x}\right)\right) \cdot \frac{-1}{2}}{x}}{\color{blue}{x}} \]
    4. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\left(\frac{\left(\mathsf{neg}\left(\sqrt{x}\right)\right) \cdot \frac{-1}{2}}{x}\right), \color{blue}{x}\right) \]
    5. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{/.f64}\left(\left(\left(\mathsf{neg}\left(\sqrt{x}\right)\right) \cdot \frac{-1}{2}\right), x\right), x\right) \]
    6. distribute-lft-neg-outN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{/.f64}\left(\left(\mathsf{neg}\left(\sqrt{x} \cdot \frac{-1}{2}\right)\right), x\right), x\right) \]
    7. neg-lowering-neg.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{/.f64}\left(\mathsf{neg.f64}\left(\left(\sqrt{x} \cdot \frac{-1}{2}\right)\right), x\right), x\right) \]
    8. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{/.f64}\left(\mathsf{neg.f64}\left(\mathsf{*.f64}\left(\left(\sqrt{x}\right), \frac{-1}{2}\right)\right), x\right), x\right) \]
    9. sqrt-lowering-sqrt.f6497.9%

      \[\leadsto \mathsf{/.f64}\left(\mathsf{/.f64}\left(\mathsf{neg.f64}\left(\mathsf{*.f64}\left(\mathsf{sqrt.f64}\left(x\right), \frac{-1}{2}\right)\right), x\right), x\right) \]
  10. Applied egg-rr97.9%

    \[\leadsto \color{blue}{\frac{\frac{-\sqrt{x} \cdot -0.5}{x}}{x}} \]
  11. Step-by-step derivation
    1. associate-/l/N/A

      \[\leadsto \frac{\mathsf{neg}\left(\sqrt{x} \cdot \frac{-1}{2}\right)}{\color{blue}{x \cdot x}} \]
    2. distribute-rgt-neg-inN/A

      \[\leadsto \frac{\sqrt{x} \cdot \left(\mathsf{neg}\left(\frac{-1}{2}\right)\right)}{\color{blue}{x} \cdot x} \]
    3. metadata-evalN/A

      \[\leadsto \frac{\sqrt{x} \cdot \frac{1}{2}}{x \cdot x} \]
    4. times-fracN/A

      \[\leadsto \frac{\sqrt{x}}{x} \cdot \color{blue}{\frac{\frac{1}{2}}{x}} \]
    5. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\left(\frac{\sqrt{x}}{x}\right), \color{blue}{\left(\frac{\frac{1}{2}}{x}\right)}\right) \]
    6. /-lowering-/.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\left(\sqrt{x}\right), x\right), \left(\frac{\color{blue}{\frac{1}{2}}}{x}\right)\right) \]
    7. sqrt-lowering-sqrt.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\mathsf{sqrt.f64}\left(x\right), x\right), \left(\frac{\frac{1}{2}}{x}\right)\right) \]
    8. /-lowering-/.f6497.9%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\mathsf{sqrt.f64}\left(x\right), x\right), \mathsf{/.f64}\left(\frac{1}{2}, \color{blue}{x}\right)\right) \]
  12. Applied egg-rr97.9%

    \[\leadsto \color{blue}{\frac{\sqrt{x}}{x} \cdot \frac{0.5}{x}} \]
  13. Add Preprocessing

Alternative 8: 35.2% accurate, 209.0× 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 35.8%

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

    \[\leadsto \mathsf{\_.f64}\left(\mathsf{/.f64}\left(1, \mathsf{sqrt.f64}\left(x\right)\right), \color{blue}{\left(\sqrt{\frac{1}{x}}\right)}\right) \]
  4. Step-by-step derivation
    1. sqrt-lowering-sqrt.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(\mathsf{/.f64}\left(1, \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{sqrt.f64}\left(\left(\frac{1}{x}\right)\right)\right) \]
    2. /-lowering-/.f6423.9%

      \[\leadsto \mathsf{\_.f64}\left(\mathsf{/.f64}\left(1, \mathsf{sqrt.f64}\left(x\right)\right), \mathsf{sqrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right)\right) \]
  5. Simplified23.9%

    \[\leadsto \frac{1}{\sqrt{x}} - \color{blue}{\sqrt{\frac{1}{x}}} \]
  6. Step-by-step derivation
    1. metadata-evalN/A

      \[\leadsto \frac{\sqrt{1}}{\sqrt{x}} - \sqrt{\frac{\color{blue}{1}}{x}} \]
    2. sqrt-divN/A

      \[\leadsto \sqrt{\frac{1}{x}} - \sqrt{\color{blue}{\frac{1}{x}}} \]
    3. +-inverses33.4%

      \[\leadsto 0 \]
  7. Applied egg-rr33.4%

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

Developer Target 1: 98.4% accurate, 1.0× speedup?

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

\\
\frac{1}{\left(x + 1\right) \cdot \sqrt{x} + x \cdot \sqrt{x + 1}}
\end{array}

Reproduce

?
herbie shell --seed 2024150 
(FPCore (x)
  :name "2isqrt (example 3.6)"
  :precision binary64
  :pre (and (> x 1.0) (< x 1e+308))

  :alt
  (! :herbie-platform default (/ 1 (+ (* (+ x 1) (sqrt x)) (* x (sqrt (+ x 1))))))

  (- (/ 1.0 (sqrt x)) (/ 1.0 (sqrt (+ x 1.0)))))