2isqrt (example 3.6)

Percentage Accurate: 38.6% → 99.5%
Time: 17.7s
Alternatives: 5
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 5 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: 38.6% 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: 99.5% accurate, 1.0× speedup?

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

\\
\frac{\frac{1}{\left({\left(1 + x\right)}^{-0.5} + {x}^{-0.5}\right) \cdot x}}{1 + x}
\end{array}
Derivation
  1. Initial program 37.6%

    \[\frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. flip--37.6%

      \[\leadsto \color{blue}{\frac{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}{\frac{1}{\sqrt{x}} + \frac{1}{\sqrt{x + 1}}}} \]
    2. clear-num37.6%

      \[\leadsto \color{blue}{\frac{1}{\frac{\frac{1}{\sqrt{x}} + \frac{1}{\sqrt{x + 1}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}}} \]
    3. inv-pow37.6%

      \[\leadsto \frac{1}{\frac{\color{blue}{{\left(\sqrt{x}\right)}^{-1}} + \frac{1}{\sqrt{x + 1}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    4. sqrt-pow237.6%

      \[\leadsto \frac{1}{\frac{\color{blue}{{x}^{\left(\frac{-1}{2}\right)}} + \frac{1}{\sqrt{x + 1}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    5. metadata-eval37.6%

      \[\leadsto \frac{1}{\frac{{x}^{\color{blue}{-0.5}} + \frac{1}{\sqrt{x + 1}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    6. inv-pow37.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + \color{blue}{{\left(\sqrt{x + 1}\right)}^{-1}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    7. sqrt-pow237.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + \color{blue}{{\left(x + 1\right)}^{\left(\frac{-1}{2}\right)}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    8. +-commutative37.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\color{blue}{\left(1 + x\right)}}^{\left(\frac{-1}{2}\right)}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    9. metadata-eval37.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{\color{blue}{-0.5}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    10. frac-times20.8%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\color{blue}{\frac{1 \cdot 1}{\sqrt{x} \cdot \sqrt{x}}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    11. metadata-eval20.8%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{\color{blue}{1}}{\sqrt{x} \cdot \sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    12. add-sqr-sqrt22.4%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{\color{blue}{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    13. frac-times24.7%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \color{blue}{\frac{1 \cdot 1}{\sqrt{x + 1} \cdot \sqrt{x + 1}}}}} \]
    14. metadata-eval24.7%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \frac{\color{blue}{1}}{\sqrt{x + 1} \cdot \sqrt{x + 1}}}} \]
    15. add-sqr-sqrt37.8%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \frac{1}{\color{blue}{x + 1}}}} \]
    16. +-commutative37.8%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \frac{1}{\color{blue}{1 + x}}}} \]
  4. Applied egg-rr37.8%

    \[\leadsto \color{blue}{\frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \frac{1}{1 + x}}}} \]
  5. Step-by-step derivation
    1. frac-sub40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\color{blue}{\frac{1 \cdot \left(1 + x\right) - x \cdot 1}{x \cdot \left(1 + x\right)}}}} \]
    2. div-inv40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\color{blue}{\left(1 \cdot \left(1 + x\right) - x \cdot 1\right) \cdot \frac{1}{x \cdot \left(1 + x\right)}}}} \]
    3. *-un-lft-identity40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\left(\color{blue}{\left(1 + x\right)} - x \cdot 1\right) \cdot \frac{1}{x \cdot \left(1 + x\right)}}} \]
    4. *-rgt-identity40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\left(\left(1 + x\right) - \color{blue}{x}\right) \cdot \frac{1}{x \cdot \left(1 + x\right)}}} \]
    5. metadata-eval40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\left(\left(1 + x\right) - x\right) \cdot \frac{\color{blue}{1 \cdot 1}}{x \cdot \left(1 + x\right)}}} \]
    6. frac-times40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\left(\left(1 + x\right) - x\right) \cdot \color{blue}{\left(\frac{1}{x} \cdot \frac{1}{1 + x}\right)}}} \]
    7. un-div-inv40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\left(\left(1 + x\right) - x\right) \cdot \color{blue}{\frac{\frac{1}{x}}{1 + x}}}} \]
  6. Applied egg-rr40.6%

    \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\color{blue}{\left(\left(1 + x\right) - x\right) \cdot \frac{\frac{1}{x}}{1 + x}}}} \]
  7. Step-by-step derivation
    1. clear-num40.6%

      \[\leadsto \color{blue}{\frac{\left(\left(1 + x\right) - x\right) \cdot \frac{\frac{1}{x}}{1 + x}}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}} \]
    2. div-inv40.6%

      \[\leadsto \color{blue}{\left(\left(\left(1 + x\right) - x\right) \cdot \frac{\frac{1}{x}}{1 + x}\right) \cdot \frac{1}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}} \]
    3. associate--l+83.2%

      \[\leadsto \left(\color{blue}{\left(1 + \left(x - x\right)\right)} \cdot \frac{\frac{1}{x}}{1 + x}\right) \cdot \frac{1}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}} \]
    4. +-inverses83.2%

      \[\leadsto \left(\left(1 + \color{blue}{0}\right) \cdot \frac{\frac{1}{x}}{1 + x}\right) \cdot \frac{1}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}} \]
    5. metadata-eval83.2%

      \[\leadsto \left(\color{blue}{1} \cdot \frac{\frac{1}{x}}{1 + x}\right) \cdot \frac{1}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}} \]
    6. *-un-lft-identity83.2%

      \[\leadsto \color{blue}{\frac{\frac{1}{x}}{1 + x}} \cdot \frac{1}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}} \]
    7. +-commutative83.2%

      \[\leadsto \frac{\frac{1}{x}}{\color{blue}{x + 1}} \cdot \frac{1}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}} \]
    8. *-un-lft-identity83.2%

      \[\leadsto \frac{\frac{1}{x}}{x + 1} \cdot \frac{1}{\color{blue}{1 \cdot \left({x}^{-0.5} + {\left(1 + x\right)}^{-0.5}\right)}} \]
    9. *-un-lft-identity83.2%

      \[\leadsto \frac{\frac{1}{x}}{x + 1} \cdot \frac{1}{\color{blue}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}} \]
    10. +-commutative83.2%

      \[\leadsto \frac{\frac{1}{x}}{x + 1} \cdot \frac{1}{{x}^{-0.5} + {\color{blue}{\left(x + 1\right)}}^{-0.5}} \]
  8. Applied egg-rr83.2%

    \[\leadsto \color{blue}{\frac{\frac{1}{x}}{x + 1} \cdot \frac{1}{{x}^{-0.5} + {\left(x + 1\right)}^{-0.5}}} \]
  9. Step-by-step derivation
    1. associate-*l/99.4%

      \[\leadsto \color{blue}{\frac{\frac{1}{x} \cdot \frac{1}{{x}^{-0.5} + {\left(x + 1\right)}^{-0.5}}}{x + 1}} \]
    2. div-inv99.5%

      \[\leadsto \frac{\color{blue}{\frac{\frac{1}{x}}{{x}^{-0.5} + {\left(x + 1\right)}^{-0.5}}}}{x + 1} \]
    3. clear-num99.5%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{{x}^{-0.5} + {\left(x + 1\right)}^{-0.5}}{\frac{1}{x}}}}}{x + 1} \]
    4. associate-/r/99.6%

      \[\leadsto \frac{\frac{1}{\color{blue}{\frac{{x}^{-0.5} + {\left(x + 1\right)}^{-0.5}}{1} \cdot x}}}{x + 1} \]
    5. /-rgt-identity99.6%

      \[\leadsto \frac{\frac{1}{\color{blue}{\left({x}^{-0.5} + {\left(x + 1\right)}^{-0.5}\right)} \cdot x}}{x + 1} \]
    6. +-commutative99.6%

      \[\leadsto \frac{\frac{1}{\color{blue}{\left({\left(x + 1\right)}^{-0.5} + {x}^{-0.5}\right)} \cdot x}}{x + 1} \]
    7. +-commutative99.6%

      \[\leadsto \frac{\frac{1}{\left({\color{blue}{\left(1 + x\right)}}^{-0.5} + {x}^{-0.5}\right) \cdot x}}{x + 1} \]
    8. +-commutative99.6%

      \[\leadsto \frac{\frac{1}{\left({\left(1 + x\right)}^{-0.5} + {x}^{-0.5}\right) \cdot x}}{\color{blue}{1 + x}} \]
  10. Applied egg-rr99.6%

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

Alternative 2: 98.2% accurate, 1.0× speedup?

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

\\
\frac{1}{\left(1 + x\right) \cdot \left(\left({\left(1 + x\right)}^{-0.5} + {x}^{-0.5}\right) \cdot x\right)}
\end{array}
Derivation
  1. Initial program 37.6%

    \[\frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. flip--37.6%

      \[\leadsto \color{blue}{\frac{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}{\frac{1}{\sqrt{x}} + \frac{1}{\sqrt{x + 1}}}} \]
    2. clear-num37.6%

      \[\leadsto \color{blue}{\frac{1}{\frac{\frac{1}{\sqrt{x}} + \frac{1}{\sqrt{x + 1}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}}} \]
    3. inv-pow37.6%

      \[\leadsto \frac{1}{\frac{\color{blue}{{\left(\sqrt{x}\right)}^{-1}} + \frac{1}{\sqrt{x + 1}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    4. sqrt-pow237.6%

      \[\leadsto \frac{1}{\frac{\color{blue}{{x}^{\left(\frac{-1}{2}\right)}} + \frac{1}{\sqrt{x + 1}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    5. metadata-eval37.6%

      \[\leadsto \frac{1}{\frac{{x}^{\color{blue}{-0.5}} + \frac{1}{\sqrt{x + 1}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    6. inv-pow37.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + \color{blue}{{\left(\sqrt{x + 1}\right)}^{-1}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    7. sqrt-pow237.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + \color{blue}{{\left(x + 1\right)}^{\left(\frac{-1}{2}\right)}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    8. +-commutative37.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\color{blue}{\left(1 + x\right)}}^{\left(\frac{-1}{2}\right)}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    9. metadata-eval37.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{\color{blue}{-0.5}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    10. frac-times20.8%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\color{blue}{\frac{1 \cdot 1}{\sqrt{x} \cdot \sqrt{x}}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    11. metadata-eval20.8%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{\color{blue}{1}}{\sqrt{x} \cdot \sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    12. add-sqr-sqrt22.4%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{\color{blue}{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    13. frac-times24.7%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \color{blue}{\frac{1 \cdot 1}{\sqrt{x + 1} \cdot \sqrt{x + 1}}}}} \]
    14. metadata-eval24.7%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \frac{\color{blue}{1}}{\sqrt{x + 1} \cdot \sqrt{x + 1}}}} \]
    15. add-sqr-sqrt37.8%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \frac{1}{\color{blue}{x + 1}}}} \]
    16. +-commutative37.8%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \frac{1}{\color{blue}{1 + x}}}} \]
  4. Applied egg-rr37.8%

    \[\leadsto \color{blue}{\frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \frac{1}{1 + x}}}} \]
  5. Step-by-step derivation
    1. frac-sub40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\color{blue}{\frac{1 \cdot \left(1 + x\right) - x \cdot 1}{x \cdot \left(1 + x\right)}}}} \]
    2. div-inv40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\color{blue}{\left(1 \cdot \left(1 + x\right) - x \cdot 1\right) \cdot \frac{1}{x \cdot \left(1 + x\right)}}}} \]
    3. *-un-lft-identity40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\left(\color{blue}{\left(1 + x\right)} - x \cdot 1\right) \cdot \frac{1}{x \cdot \left(1 + x\right)}}} \]
    4. *-rgt-identity40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\left(\left(1 + x\right) - \color{blue}{x}\right) \cdot \frac{1}{x \cdot \left(1 + x\right)}}} \]
    5. metadata-eval40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\left(\left(1 + x\right) - x\right) \cdot \frac{\color{blue}{1 \cdot 1}}{x \cdot \left(1 + x\right)}}} \]
    6. frac-times40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\left(\left(1 + x\right) - x\right) \cdot \color{blue}{\left(\frac{1}{x} \cdot \frac{1}{1 + x}\right)}}} \]
    7. un-div-inv40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\left(\left(1 + x\right) - x\right) \cdot \color{blue}{\frac{\frac{1}{x}}{1 + x}}}} \]
  6. Applied egg-rr40.6%

    \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\color{blue}{\left(\left(1 + x\right) - x\right) \cdot \frac{\frac{1}{x}}{1 + x}}}} \]
  7. Step-by-step derivation
    1. clear-num40.6%

      \[\leadsto \color{blue}{\frac{\left(\left(1 + x\right) - x\right) \cdot \frac{\frac{1}{x}}{1 + x}}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}} \]
    2. div-inv40.6%

      \[\leadsto \color{blue}{\left(\left(\left(1 + x\right) - x\right) \cdot \frac{\frac{1}{x}}{1 + x}\right) \cdot \frac{1}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}} \]
    3. associate--l+83.2%

      \[\leadsto \left(\color{blue}{\left(1 + \left(x - x\right)\right)} \cdot \frac{\frac{1}{x}}{1 + x}\right) \cdot \frac{1}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}} \]
    4. +-inverses83.2%

      \[\leadsto \left(\left(1 + \color{blue}{0}\right) \cdot \frac{\frac{1}{x}}{1 + x}\right) \cdot \frac{1}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}} \]
    5. metadata-eval83.2%

      \[\leadsto \left(\color{blue}{1} \cdot \frac{\frac{1}{x}}{1 + x}\right) \cdot \frac{1}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}} \]
    6. *-un-lft-identity83.2%

      \[\leadsto \color{blue}{\frac{\frac{1}{x}}{1 + x}} \cdot \frac{1}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}} \]
    7. +-commutative83.2%

      \[\leadsto \frac{\frac{1}{x}}{\color{blue}{x + 1}} \cdot \frac{1}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}} \]
    8. *-un-lft-identity83.2%

      \[\leadsto \frac{\frac{1}{x}}{x + 1} \cdot \frac{1}{\color{blue}{1 \cdot \left({x}^{-0.5} + {\left(1 + x\right)}^{-0.5}\right)}} \]
    9. *-un-lft-identity83.2%

      \[\leadsto \frac{\frac{1}{x}}{x + 1} \cdot \frac{1}{\color{blue}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}} \]
    10. +-commutative83.2%

      \[\leadsto \frac{\frac{1}{x}}{x + 1} \cdot \frac{1}{{x}^{-0.5} + {\color{blue}{\left(x + 1\right)}}^{-0.5}} \]
  8. Applied egg-rr83.2%

    \[\leadsto \color{blue}{\frac{\frac{1}{x}}{x + 1} \cdot \frac{1}{{x}^{-0.5} + {\left(x + 1\right)}^{-0.5}}} \]
  9. Step-by-step derivation
    1. associate-*l/99.4%

      \[\leadsto \color{blue}{\frac{\frac{1}{x} \cdot \frac{1}{{x}^{-0.5} + {\left(x + 1\right)}^{-0.5}}}{x + 1}} \]
    2. div-inv99.5%

      \[\leadsto \frac{\color{blue}{\frac{\frac{1}{x}}{{x}^{-0.5} + {\left(x + 1\right)}^{-0.5}}}}{x + 1} \]
    3. clear-num99.5%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{{x}^{-0.5} + {\left(x + 1\right)}^{-0.5}}{\frac{1}{x}}}}}{x + 1} \]
    4. associate-/r*98.8%

      \[\leadsto \color{blue}{\frac{1}{\frac{{x}^{-0.5} + {\left(x + 1\right)}^{-0.5}}{\frac{1}{x}} \cdot \left(x + 1\right)}} \]
    5. *-commutative98.8%

      \[\leadsto \frac{1}{\color{blue}{\left(x + 1\right) \cdot \frac{{x}^{-0.5} + {\left(x + 1\right)}^{-0.5}}{\frac{1}{x}}}} \]
    6. +-commutative98.8%

      \[\leadsto \frac{1}{\color{blue}{\left(1 + x\right)} \cdot \frac{{x}^{-0.5} + {\left(x + 1\right)}^{-0.5}}{\frac{1}{x}}} \]
    7. associate-/r/98.8%

      \[\leadsto \frac{1}{\left(1 + x\right) \cdot \color{blue}{\left(\frac{{x}^{-0.5} + {\left(x + 1\right)}^{-0.5}}{1} \cdot x\right)}} \]
    8. /-rgt-identity98.8%

      \[\leadsto \frac{1}{\left(1 + x\right) \cdot \left(\color{blue}{\left({x}^{-0.5} + {\left(x + 1\right)}^{-0.5}\right)} \cdot x\right)} \]
    9. +-commutative98.8%

      \[\leadsto \frac{1}{\left(1 + x\right) \cdot \left(\color{blue}{\left({\left(x + 1\right)}^{-0.5} + {x}^{-0.5}\right)} \cdot x\right)} \]
    10. +-commutative98.8%

      \[\leadsto \frac{1}{\left(1 + x\right) \cdot \left(\left({\color{blue}{\left(1 + x\right)}}^{-0.5} + {x}^{-0.5}\right) \cdot x\right)} \]
  10. Applied egg-rr98.8%

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

Alternative 3: 99.5% accurate, 1.0× speedup?

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

\\
\frac{\frac{1}{x}}{\left({\left(1 + x\right)}^{-0.5} + {x}^{-0.5}\right) \cdot \left(1 + x\right)}
\end{array}
Derivation
  1. Initial program 37.6%

    \[\frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. flip--37.6%

      \[\leadsto \color{blue}{\frac{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}{\frac{1}{\sqrt{x}} + \frac{1}{\sqrt{x + 1}}}} \]
    2. clear-num37.6%

      \[\leadsto \color{blue}{\frac{1}{\frac{\frac{1}{\sqrt{x}} + \frac{1}{\sqrt{x + 1}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}}} \]
    3. inv-pow37.6%

      \[\leadsto \frac{1}{\frac{\color{blue}{{\left(\sqrt{x}\right)}^{-1}} + \frac{1}{\sqrt{x + 1}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    4. sqrt-pow237.6%

      \[\leadsto \frac{1}{\frac{\color{blue}{{x}^{\left(\frac{-1}{2}\right)}} + \frac{1}{\sqrt{x + 1}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    5. metadata-eval37.6%

      \[\leadsto \frac{1}{\frac{{x}^{\color{blue}{-0.5}} + \frac{1}{\sqrt{x + 1}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    6. inv-pow37.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + \color{blue}{{\left(\sqrt{x + 1}\right)}^{-1}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    7. sqrt-pow237.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + \color{blue}{{\left(x + 1\right)}^{\left(\frac{-1}{2}\right)}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    8. +-commutative37.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\color{blue}{\left(1 + x\right)}}^{\left(\frac{-1}{2}\right)}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    9. metadata-eval37.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{\color{blue}{-0.5}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    10. frac-times20.8%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\color{blue}{\frac{1 \cdot 1}{\sqrt{x} \cdot \sqrt{x}}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    11. metadata-eval20.8%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{\color{blue}{1}}{\sqrt{x} \cdot \sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    12. add-sqr-sqrt22.4%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{\color{blue}{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    13. frac-times24.7%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \color{blue}{\frac{1 \cdot 1}{\sqrt{x + 1} \cdot \sqrt{x + 1}}}}} \]
    14. metadata-eval24.7%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \frac{\color{blue}{1}}{\sqrt{x + 1} \cdot \sqrt{x + 1}}}} \]
    15. add-sqr-sqrt37.8%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \frac{1}{\color{blue}{x + 1}}}} \]
    16. +-commutative37.8%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \frac{1}{\color{blue}{1 + x}}}} \]
  4. Applied egg-rr37.8%

    \[\leadsto \color{blue}{\frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \frac{1}{1 + x}}}} \]
  5. Step-by-step derivation
    1. frac-sub40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\color{blue}{\frac{1 \cdot \left(1 + x\right) - x \cdot 1}{x \cdot \left(1 + x\right)}}}} \]
    2. div-inv40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\color{blue}{\left(1 \cdot \left(1 + x\right) - x \cdot 1\right) \cdot \frac{1}{x \cdot \left(1 + x\right)}}}} \]
    3. *-un-lft-identity40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\left(\color{blue}{\left(1 + x\right)} - x \cdot 1\right) \cdot \frac{1}{x \cdot \left(1 + x\right)}}} \]
    4. *-rgt-identity40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\left(\left(1 + x\right) - \color{blue}{x}\right) \cdot \frac{1}{x \cdot \left(1 + x\right)}}} \]
    5. metadata-eval40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\left(\left(1 + x\right) - x\right) \cdot \frac{\color{blue}{1 \cdot 1}}{x \cdot \left(1 + x\right)}}} \]
    6. frac-times40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\left(\left(1 + x\right) - x\right) \cdot \color{blue}{\left(\frac{1}{x} \cdot \frac{1}{1 + x}\right)}}} \]
    7. un-div-inv40.6%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\left(\left(1 + x\right) - x\right) \cdot \color{blue}{\frac{\frac{1}{x}}{1 + x}}}} \]
  6. Applied egg-rr40.6%

    \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\color{blue}{\left(\left(1 + x\right) - x\right) \cdot \frac{\frac{1}{x}}{1 + x}}}} \]
  7. Step-by-step derivation
    1. clear-num40.6%

      \[\leadsto \color{blue}{\frac{\left(\left(1 + x\right) - x\right) \cdot \frac{\frac{1}{x}}{1 + x}}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}} \]
    2. div-inv40.6%

      \[\leadsto \color{blue}{\left(\left(\left(1 + x\right) - x\right) \cdot \frac{\frac{1}{x}}{1 + x}\right) \cdot \frac{1}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}} \]
    3. associate--l+83.2%

      \[\leadsto \left(\color{blue}{\left(1 + \left(x - x\right)\right)} \cdot \frac{\frac{1}{x}}{1 + x}\right) \cdot \frac{1}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}} \]
    4. +-inverses83.2%

      \[\leadsto \left(\left(1 + \color{blue}{0}\right) \cdot \frac{\frac{1}{x}}{1 + x}\right) \cdot \frac{1}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}} \]
    5. metadata-eval83.2%

      \[\leadsto \left(\color{blue}{1} \cdot \frac{\frac{1}{x}}{1 + x}\right) \cdot \frac{1}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}} \]
    6. *-un-lft-identity83.2%

      \[\leadsto \color{blue}{\frac{\frac{1}{x}}{1 + x}} \cdot \frac{1}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}} \]
    7. +-commutative83.2%

      \[\leadsto \frac{\frac{1}{x}}{\color{blue}{x + 1}} \cdot \frac{1}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}} \]
    8. *-un-lft-identity83.2%

      \[\leadsto \frac{\frac{1}{x}}{x + 1} \cdot \frac{1}{\color{blue}{1 \cdot \left({x}^{-0.5} + {\left(1 + x\right)}^{-0.5}\right)}} \]
    9. *-un-lft-identity83.2%

      \[\leadsto \frac{\frac{1}{x}}{x + 1} \cdot \frac{1}{\color{blue}{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}} \]
    10. +-commutative83.2%

      \[\leadsto \frac{\frac{1}{x}}{x + 1} \cdot \frac{1}{{x}^{-0.5} + {\color{blue}{\left(x + 1\right)}}^{-0.5}} \]
  8. Applied egg-rr83.2%

    \[\leadsto \color{blue}{\frac{\frac{1}{x}}{x + 1} \cdot \frac{1}{{x}^{-0.5} + {\left(x + 1\right)}^{-0.5}}} \]
  9. Step-by-step derivation
    1. *-commutative83.2%

      \[\leadsto \color{blue}{\frac{1}{{x}^{-0.5} + {\left(x + 1\right)}^{-0.5}} \cdot \frac{\frac{1}{x}}{x + 1}} \]
    2. frac-times99.5%

      \[\leadsto \color{blue}{\frac{1 \cdot \frac{1}{x}}{\left({x}^{-0.5} + {\left(x + 1\right)}^{-0.5}\right) \cdot \left(x + 1\right)}} \]
    3. *-un-lft-identity99.5%

      \[\leadsto \frac{\color{blue}{\frac{1}{x}}}{\left({x}^{-0.5} + {\left(x + 1\right)}^{-0.5}\right) \cdot \left(x + 1\right)} \]
    4. +-commutative99.5%

      \[\leadsto \frac{\frac{1}{x}}{\color{blue}{\left({\left(x + 1\right)}^{-0.5} + {x}^{-0.5}\right)} \cdot \left(x + 1\right)} \]
    5. +-commutative99.5%

      \[\leadsto \frac{\frac{1}{x}}{\left({\color{blue}{\left(1 + x\right)}}^{-0.5} + {x}^{-0.5}\right) \cdot \left(x + 1\right)} \]
    6. +-commutative99.5%

      \[\leadsto \frac{\frac{1}{x}}{\left({\left(1 + x\right)}^{-0.5} + {x}^{-0.5}\right) \cdot \color{blue}{\left(1 + x\right)}} \]
  10. Applied egg-rr99.5%

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

Alternative 4: 97.9% accurate, 2.0× speedup?

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

\\
0.5 \cdot {x}^{-1.5}
\end{array}
Derivation
  1. Initial program 37.6%

    \[\frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. add-exp-log37.6%

      \[\leadsto \color{blue}{e^{\log \left(\frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}}\right)}} \]
    2. inv-pow37.2%

      \[\leadsto e^{\log \left(\color{blue}{{\left(\sqrt{x}\right)}^{-1}} - \frac{1}{\sqrt{x + 1}}\right)} \]
    3. sqrt-pow230.8%

      \[\leadsto e^{\log \left(\color{blue}{{x}^{\left(\frac{-1}{2}\right)}} - \frac{1}{\sqrt{x + 1}}\right)} \]
    4. metadata-eval30.8%

      \[\leadsto e^{\log \left({x}^{\color{blue}{-0.5}} - \frac{1}{\sqrt{x + 1}}\right)} \]
    5. inv-pow31.2%

      \[\leadsto e^{\log \left({x}^{-0.5} - \color{blue}{{\left(\sqrt{x + 1}\right)}^{-1}}\right)} \]
    6. sqrt-pow237.7%

      \[\leadsto e^{\log \left({x}^{-0.5} - \color{blue}{{\left(x + 1\right)}^{\left(\frac{-1}{2}\right)}}\right)} \]
    7. +-commutative37.7%

      \[\leadsto e^{\log \left({x}^{-0.5} - {\color{blue}{\left(1 + x\right)}}^{\left(\frac{-1}{2}\right)}\right)} \]
    8. metadata-eval37.7%

      \[\leadsto e^{\log \left({x}^{-0.5} - {\left(1 + x\right)}^{\color{blue}{-0.5}}\right)} \]
  4. Applied egg-rr37.7%

    \[\leadsto \color{blue}{e^{\log \left({x}^{-0.5} - {\left(1 + x\right)}^{-0.5}\right)}} \]
  5. Taylor expanded in x around inf 90.6%

    \[\leadsto e^{\color{blue}{\log \left(--0.5 \cdot \sqrt{x}\right) + 2 \cdot \log \left(\frac{1}{x}\right)}} \]
  6. Step-by-step derivation
    1. exp-sum76.5%

      \[\leadsto \color{blue}{e^{\log \left(--0.5 \cdot \sqrt{x}\right)} \cdot e^{2 \cdot \log \left(\frac{1}{x}\right)}} \]
    2. add-exp-log76.3%

      \[\leadsto \color{blue}{\left(--0.5 \cdot \sqrt{x}\right)} \cdot e^{2 \cdot \log \left(\frac{1}{x}\right)} \]
    3. distribute-lft-neg-in76.3%

      \[\leadsto \color{blue}{\left(\left(--0.5\right) \cdot \sqrt{x}\right)} \cdot e^{2 \cdot \log \left(\frac{1}{x}\right)} \]
    4. metadata-eval76.3%

      \[\leadsto \left(\color{blue}{0.5} \cdot \sqrt{x}\right) \cdot e^{2 \cdot \log \left(\frac{1}{x}\right)} \]
    5. associate-*l*76.3%

      \[\leadsto \color{blue}{0.5 \cdot \left(\sqrt{x} \cdot e^{2 \cdot \log \left(\frac{1}{x}\right)}\right)} \]
    6. *-commutative76.3%

      \[\leadsto 0.5 \cdot \left(\sqrt{x} \cdot e^{\color{blue}{\log \left(\frac{1}{x}\right) \cdot 2}}\right) \]
    7. exp-to-pow80.2%

      \[\leadsto 0.5 \cdot \left(\sqrt{x} \cdot \color{blue}{{\left(\frac{1}{x}\right)}^{2}}\right) \]
    8. pow280.2%

      \[\leadsto 0.5 \cdot \left(\sqrt{x} \cdot \color{blue}{\left(\frac{1}{x} \cdot \frac{1}{x}\right)}\right) \]
    9. inv-pow80.2%

      \[\leadsto 0.5 \cdot \left(\sqrt{x} \cdot \left(\color{blue}{{x}^{-1}} \cdot \frac{1}{x}\right)\right) \]
    10. inv-pow80.2%

      \[\leadsto 0.5 \cdot \left(\sqrt{x} \cdot \left({x}^{-1} \cdot \color{blue}{{x}^{-1}}\right)\right) \]
    11. pow-prod-up80.4%

      \[\leadsto 0.5 \cdot \left(\sqrt{x} \cdot \color{blue}{{x}^{\left(-1 + -1\right)}}\right) \]
    12. metadata-eval80.4%

      \[\leadsto 0.5 \cdot \left(\sqrt{x} \cdot {x}^{\color{blue}{-2}}\right) \]
  7. Applied egg-rr80.4%

    \[\leadsto \color{blue}{0.5 \cdot \left(\sqrt{x} \cdot {x}^{-2}\right)} \]
  8. Step-by-step derivation
    1. pow1/280.4%

      \[\leadsto 0.5 \cdot \left(\color{blue}{{x}^{0.5}} \cdot {x}^{-2}\right) \]
    2. pow-prod-up97.0%

      \[\leadsto 0.5 \cdot \color{blue}{{x}^{\left(0.5 + -2\right)}} \]
    3. metadata-eval97.0%

      \[\leadsto 0.5 \cdot {x}^{\color{blue}{-1.5}} \]
  9. Applied egg-rr97.0%

    \[\leadsto 0.5 \cdot \color{blue}{{x}^{-1.5}} \]
  10. Add Preprocessing

Alternative 5: 5.6% accurate, 2.0× speedup?

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

\\
{x}^{-0.5}
\end{array}
Derivation
  1. Initial program 37.6%

    \[\frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0 5.7%

    \[\leadsto \color{blue}{\sqrt{\frac{1}{x}}} \]
  4. Step-by-step derivation
    1. inv-pow5.7%

      \[\leadsto \sqrt{\color{blue}{{x}^{-1}}} \]
    2. sqrt-pow15.7%

      \[\leadsto \color{blue}{{x}^{\left(\frac{-1}{2}\right)}} \]
    3. metadata-eval5.7%

      \[\leadsto {x}^{\color{blue}{-0.5}} \]
  5. Applied egg-rr5.7%

    \[\leadsto \color{blue}{{x}^{-0.5}} \]
  6. Add Preprocessing

Developer target: 98.3% 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 2024076 -o generate:simplify
(FPCore (x)
  :name "2isqrt (example 3.6)"
  :precision binary64
  :pre (and (> x 1.0) (< x 1e+308))

  :alt
  (/ 1.0 (+ (* (+ x 1.0) (sqrt x)) (* x (sqrt (+ x 1.0)))))

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