2isqrt (example 3.6)

Percentage Accurate: 39.1% → 99.2%
Time: 14.6s
Alternatives: 7
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 7 alternatives:

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

Initial Program: 39.1% 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: 99.2% accurate, 0.3× speedup?

\[\begin{array}{l} \\ {\left(\mathsf{hypot}\left(\sqrt{x}, x\right) \cdot \mathsf{hypot}\left({\left(x + 1\right)}^{-0.25}, {x}^{-0.25}\right)\right)}^{-2} \end{array} \]
(FPCore (x)
 :precision binary64
 (pow (* (hypot (sqrt x) x) (hypot (pow (+ x 1.0) -0.25) (pow x -0.25))) -2.0))
double code(double x) {
	return pow((hypot(sqrt(x), x) * hypot(pow((x + 1.0), -0.25), pow(x, -0.25))), -2.0);
}
public static double code(double x) {
	return Math.pow((Math.hypot(Math.sqrt(x), x) * Math.hypot(Math.pow((x + 1.0), -0.25), Math.pow(x, -0.25))), -2.0);
}
def code(x):
	return math.pow((math.hypot(math.sqrt(x), x) * math.hypot(math.pow((x + 1.0), -0.25), math.pow(x, -0.25))), -2.0)
function code(x)
	return Float64(hypot(sqrt(x), x) * hypot((Float64(x + 1.0) ^ -0.25), (x ^ -0.25))) ^ -2.0
end
function tmp = code(x)
	tmp = (hypot(sqrt(x), x) * hypot(((x + 1.0) ^ -0.25), (x ^ -0.25))) ^ -2.0;
end
code[x_] := N[Power[N[(N[Sqrt[N[Sqrt[x], $MachinePrecision] ^ 2 + x ^ 2], $MachinePrecision] * N[Sqrt[N[Power[N[(x + 1.0), $MachinePrecision], -0.25], $MachinePrecision] ^ 2 + N[Power[x, -0.25], $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision], -2.0], $MachinePrecision]
\begin{array}{l}

\\
{\left(\mathsf{hypot}\left(\sqrt{x}, x\right) \cdot \mathsf{hypot}\left({\left(x + 1\right)}^{-0.25}, {x}^{-0.25}\right)\right)}^{-2}
\end{array}
Derivation
  1. Initial program 38.0%

    \[\frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. flip--37.9%

      \[\leadsto \color{blue}{\frac{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}{\frac{1}{\sqrt{x}} + \frac{1}{\sqrt{x + 1}}}} \]
    2. clear-num37.9%

      \[\leadsto \color{blue}{\frac{1}{\frac{\frac{1}{\sqrt{x}} + \frac{1}{\sqrt{x + 1}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}}} \]
    3. inv-pow37.9%

      \[\leadsto \frac{1}{\frac{\color{blue}{{\left(\sqrt{x}\right)}^{-1}} + \frac{1}{\sqrt{x + 1}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    4. sqrt-pow237.9%

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

      \[\leadsto \frac{1}{\frac{{x}^{\color{blue}{-0.5}} + \frac{1}{\sqrt{x + 1}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    6. inv-pow37.9%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + \color{blue}{{\left(\sqrt{x + 1}\right)}^{-1}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    7. sqrt-pow237.9%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + \color{blue}{{\left(x + 1\right)}^{\left(\frac{-1}{2}\right)}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    8. +-commutative37.9%

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

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{\color{blue}{-0.5}}}{\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    10. frac-times21.0%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\color{blue}{\frac{1 \cdot 1}{\sqrt{x} \cdot \sqrt{x}}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    11. metadata-eval21.0%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{\color{blue}{1}}{\sqrt{x} \cdot \sqrt{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    12. add-sqr-sqrt18.8%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{\color{blue}{x}} - \frac{1}{\sqrt{x + 1}} \cdot \frac{1}{\sqrt{x + 1}}}} \]
    13. frac-times26.1%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \color{blue}{\frac{1 \cdot 1}{\sqrt{x + 1} \cdot \sqrt{x + 1}}}}} \]
    14. metadata-eval26.1%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \frac{\color{blue}{1}}{\sqrt{x + 1} \cdot \sqrt{x + 1}}}} \]
    15. add-sqr-sqrt38.1%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \frac{1}{\color{blue}{x + 1}}}} \]
    16. +-commutative38.1%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \frac{1}{\color{blue}{1 + x}}}} \]
  4. Applied egg-rr38.1%

    \[\leadsto \color{blue}{\frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1}{x} - \frac{1}{1 + x}}}} \]
  5. Step-by-step derivation
    1. frac-sub40.3%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\color{blue}{\frac{1 \cdot \left(1 + x\right) - x \cdot 1}{x \cdot \left(1 + x\right)}}}} \]
    2. div-inv40.3%

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

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

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\left(\left(1 + x\right) - \color{blue}{x}\right) \cdot \frac{1}{x \cdot \left(1 + x\right)}}} \]
  6. Applied egg-rr40.3%

    \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\color{blue}{\left(\left(1 + x\right) - x\right) \cdot \frac{1}{x \cdot \left(1 + x\right)}}}} \]
  7. Step-by-step derivation
    1. associate-*r/40.3%

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

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{\color{blue}{\left(1 + x\right) - x}}{x \cdot \left(1 + x\right)}}} \]
    3. associate--l+81.0%

      \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{\color{blue}{1 + \left(x - x\right)}}{x \cdot \left(1 + x\right)}}} \]
  8. Simplified81.0%

    \[\leadsto \frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\color{blue}{\frac{1 + \left(x - x\right)}{x \cdot \left(1 + x\right)}}}} \]
  9. Step-by-step derivation
    1. add-sqr-sqrt80.9%

      \[\leadsto \color{blue}{\sqrt{\frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1 + \left(x - x\right)}{x \cdot \left(1 + x\right)}}}} \cdot \sqrt{\frac{1}{\frac{{x}^{-0.5} + {\left(1 + x\right)}^{-0.5}}{\frac{1 + \left(x - x\right)}{x \cdot \left(1 + x\right)}}}}} \]
  10. Applied egg-rr99.2%

    \[\leadsto \color{blue}{\frac{1}{\mathsf{hypot}\left({\left(x + 1\right)}^{-0.25}, {x}^{-0.25}\right) \cdot \mathsf{hypot}\left(\sqrt{x}, x\right)} \cdot \frac{1}{\mathsf{hypot}\left({\left(x + 1\right)}^{-0.25}, {x}^{-0.25}\right) \cdot \mathsf{hypot}\left(\sqrt{x}, x\right)}} \]
  11. Step-by-step derivation
    1. unpow-199.2%

      \[\leadsto \color{blue}{{\left(\mathsf{hypot}\left({\left(x + 1\right)}^{-0.25}, {x}^{-0.25}\right) \cdot \mathsf{hypot}\left(\sqrt{x}, x\right)\right)}^{-1}} \cdot \frac{1}{\mathsf{hypot}\left({\left(x + 1\right)}^{-0.25}, {x}^{-0.25}\right) \cdot \mathsf{hypot}\left(\sqrt{x}, x\right)} \]
    2. unpow-199.2%

      \[\leadsto {\left(\mathsf{hypot}\left({\left(x + 1\right)}^{-0.25}, {x}^{-0.25}\right) \cdot \mathsf{hypot}\left(\sqrt{x}, x\right)\right)}^{-1} \cdot \color{blue}{{\left(\mathsf{hypot}\left({\left(x + 1\right)}^{-0.25}, {x}^{-0.25}\right) \cdot \mathsf{hypot}\left(\sqrt{x}, x\right)\right)}^{-1}} \]
    3. pow-sqr99.2%

      \[\leadsto \color{blue}{{\left(\mathsf{hypot}\left({\left(x + 1\right)}^{-0.25}, {x}^{-0.25}\right) \cdot \mathsf{hypot}\left(\sqrt{x}, x\right)\right)}^{\left(2 \cdot -1\right)}} \]
    4. metadata-eval99.2%

      \[\leadsto {\left(\mathsf{hypot}\left({\left(x + 1\right)}^{-0.25}, {x}^{-0.25}\right) \cdot \mathsf{hypot}\left(\sqrt{x}, x\right)\right)}^{\color{blue}{-2}} \]
    5. *-commutative99.2%

      \[\leadsto {\color{blue}{\left(\mathsf{hypot}\left(\sqrt{x}, x\right) \cdot \mathsf{hypot}\left({\left(x + 1\right)}^{-0.25}, {x}^{-0.25}\right)\right)}}^{-2} \]
  12. Simplified99.2%

    \[\leadsto \color{blue}{{\left(\mathsf{hypot}\left(\sqrt{x}, x\right) \cdot \mathsf{hypot}\left({\left(x + 1\right)}^{-0.25}, {x}^{-0.25}\right)\right)}^{-2}} \]
  13. Final simplification99.2%

    \[\leadsto {\left(\mathsf{hypot}\left(\sqrt{x}, x\right) \cdot \mathsf{hypot}\left({\left(x + 1\right)}^{-0.25}, {x}^{-0.25}\right)\right)}^{-2} \]
  14. Add Preprocessing

Alternative 2: 98.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(\frac{0.5}{x} - \frac{0.125}{{x}^{2}}\right) \cdot {\left(x + 1\right)}^{-0.5} \end{array} \]
(FPCore (x)
 :precision binary64
 (* (- (/ 0.5 x) (/ 0.125 (pow x 2.0))) (pow (+ x 1.0) -0.5)))
double code(double x) {
	return ((0.5 / x) - (0.125 / pow(x, 2.0))) * pow((x + 1.0), -0.5);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = ((0.5d0 / x) - (0.125d0 / (x ** 2.0d0))) * ((x + 1.0d0) ** (-0.5d0))
end function
public static double code(double x) {
	return ((0.5 / x) - (0.125 / Math.pow(x, 2.0))) * Math.pow((x + 1.0), -0.5);
}
def code(x):
	return ((0.5 / x) - (0.125 / math.pow(x, 2.0))) * math.pow((x + 1.0), -0.5)
function code(x)
	return Float64(Float64(Float64(0.5 / x) - Float64(0.125 / (x ^ 2.0))) * (Float64(x + 1.0) ^ -0.5))
end
function tmp = code(x)
	tmp = ((0.5 / x) - (0.125 / (x ^ 2.0))) * ((x + 1.0) ^ -0.5);
end
code[x_] := N[(N[(N[(0.5 / x), $MachinePrecision] - N[(0.125 / N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Power[N[(x + 1.0), $MachinePrecision], -0.5], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\frac{0.5}{x} - \frac{0.125}{{x}^{2}}\right) \cdot {\left(x + 1\right)}^{-0.5}
\end{array}
Derivation
  1. Initial program 38.0%

    \[\frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. frac-sub38.0%

      \[\leadsto \color{blue}{\frac{1 \cdot \sqrt{x + 1} - \sqrt{x} \cdot 1}{\sqrt{x} \cdot \sqrt{x + 1}}} \]
    2. div-inv38.0%

      \[\leadsto \color{blue}{\left(1 \cdot \sqrt{x + 1} - \sqrt{x} \cdot 1\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}}} \]
    3. *-un-lft-identity38.0%

      \[\leadsto \left(\color{blue}{\sqrt{x + 1}} - \sqrt{x} \cdot 1\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}} \]
    4. +-commutative38.0%

      \[\leadsto \left(\sqrt{\color{blue}{1 + x}} - \sqrt{x} \cdot 1\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}} \]
    5. *-rgt-identity38.0%

      \[\leadsto \left(\sqrt{1 + x} - \color{blue}{\sqrt{x}}\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}} \]
    6. metadata-eval38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\color{blue}{1 \cdot 1}}{\sqrt{x} \cdot \sqrt{x + 1}} \]
    7. frac-times38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \color{blue}{\left(\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x + 1}}\right)} \]
    8. associate-*l/38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \color{blue}{\frac{1 \cdot \frac{1}{\sqrt{x + 1}}}{\sqrt{x}}} \]
    9. *-un-lft-identity38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\color{blue}{\frac{1}{\sqrt{x + 1}}}}{\sqrt{x}} \]
    10. pow1/238.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\frac{1}{\color{blue}{{\left(x + 1\right)}^{0.5}}}}{\sqrt{x}} \]
    11. pow-flip38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\color{blue}{{\left(x + 1\right)}^{\left(-0.5\right)}}}{\sqrt{x}} \]
    12. +-commutative38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{{\color{blue}{\left(1 + x\right)}}^{\left(-0.5\right)}}{\sqrt{x}} \]
    13. metadata-eval38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{{\left(1 + x\right)}^{\color{blue}{-0.5}}}{\sqrt{x}} \]
  4. Applied egg-rr38.0%

    \[\leadsto \color{blue}{\left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{\sqrt{x}}} \]
  5. Step-by-step derivation
    1. *-commutative38.0%

      \[\leadsto \color{blue}{\frac{{\left(1 + x\right)}^{-0.5}}{\sqrt{x}} \cdot \left(\sqrt{1 + x} - \sqrt{x}\right)} \]
    2. /-rgt-identity38.0%

      \[\leadsto \frac{{\left(1 + x\right)}^{-0.5}}{\sqrt{x}} \cdot \color{blue}{\frac{\sqrt{1 + x} - \sqrt{x}}{1}} \]
    3. times-frac38.0%

      \[\leadsto \color{blue}{\frac{{\left(1 + x\right)}^{-0.5} \cdot \left(\sqrt{1 + x} - \sqrt{x}\right)}{\sqrt{x} \cdot 1}} \]
    4. *-commutative38.0%

      \[\leadsto \frac{\color{blue}{\left(\sqrt{1 + x} - \sqrt{x}\right) \cdot {\left(1 + x\right)}^{-0.5}}}{\sqrt{x} \cdot 1} \]
    5. times-frac38.0%

      \[\leadsto \color{blue}{\frac{\sqrt{1 + x} - \sqrt{x}}{\sqrt{x}} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1}} \]
    6. div-sub38.0%

      \[\leadsto \color{blue}{\left(\frac{\sqrt{1 + x}}{\sqrt{x}} - \frac{\sqrt{x}}{\sqrt{x}}\right)} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    7. sub-neg38.0%

      \[\leadsto \color{blue}{\left(\frac{\sqrt{1 + x}}{\sqrt{x}} + \left(-\frac{\sqrt{x}}{\sqrt{x}}\right)\right)} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    8. *-inverses38.0%

      \[\leadsto \left(\frac{\sqrt{1 + x}}{\sqrt{x}} + \left(-\color{blue}{1}\right)\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    9. metadata-eval38.0%

      \[\leadsto \left(\frac{\sqrt{1 + x}}{\sqrt{x}} + \color{blue}{-1}\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
  6. Simplified38.0%

    \[\leadsto \color{blue}{\left(\frac{\sqrt{1 + x}}{\sqrt{x}} + -1\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1}} \]
  7. Taylor expanded in x around inf 98.8%

    \[\leadsto \color{blue}{\left(0.5 \cdot \frac{1}{x} - 0.125 \cdot \frac{1}{{x}^{2}}\right)} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
  8. Step-by-step derivation
    1. associate-*r/98.8%

      \[\leadsto \left(\color{blue}{\frac{0.5 \cdot 1}{x}} - 0.125 \cdot \frac{1}{{x}^{2}}\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    2. metadata-eval98.8%

      \[\leadsto \left(\frac{\color{blue}{0.5}}{x} - 0.125 \cdot \frac{1}{{x}^{2}}\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    3. associate-*r/98.8%

      \[\leadsto \left(\frac{0.5}{x} - \color{blue}{\frac{0.125 \cdot 1}{{x}^{2}}}\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    4. metadata-eval98.8%

      \[\leadsto \left(\frac{0.5}{x} - \frac{\color{blue}{0.125}}{{x}^{2}}\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
  9. Simplified98.8%

    \[\leadsto \color{blue}{\left(\frac{0.5}{x} - \frac{0.125}{{x}^{2}}\right)} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
  10. Final simplification98.8%

    \[\leadsto \left(\frac{0.5}{x} - \frac{0.125}{{x}^{2}}\right) \cdot {\left(x + 1\right)}^{-0.5} \]
  11. Add Preprocessing

Alternative 3: 98.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{\frac{0.5}{x} + -0.125 \cdot {x}^{-2}}{\sqrt{x + 1}} \end{array} \]
(FPCore (x)
 :precision binary64
 (/ (+ (/ 0.5 x) (* -0.125 (pow x -2.0))) (sqrt (+ x 1.0))))
double code(double x) {
	return ((0.5 / x) + (-0.125 * pow(x, -2.0))) / sqrt((x + 1.0));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = ((0.5d0 / x) + ((-0.125d0) * (x ** (-2.0d0)))) / sqrt((x + 1.0d0))
end function
public static double code(double x) {
	return ((0.5 / x) + (-0.125 * Math.pow(x, -2.0))) / Math.sqrt((x + 1.0));
}
def code(x):
	return ((0.5 / x) + (-0.125 * math.pow(x, -2.0))) / math.sqrt((x + 1.0))
function code(x)
	return Float64(Float64(Float64(0.5 / x) + Float64(-0.125 * (x ^ -2.0))) / sqrt(Float64(x + 1.0)))
end
function tmp = code(x)
	tmp = ((0.5 / x) + (-0.125 * (x ^ -2.0))) / sqrt((x + 1.0));
end
code[x_] := N[(N[(N[(0.5 / x), $MachinePrecision] + N[(-0.125 * N[Power[x, -2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{0.5}{x} + -0.125 \cdot {x}^{-2}}{\sqrt{x + 1}}
\end{array}
Derivation
  1. Initial program 38.0%

    \[\frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. frac-sub38.0%

      \[\leadsto \color{blue}{\frac{1 \cdot \sqrt{x + 1} - \sqrt{x} \cdot 1}{\sqrt{x} \cdot \sqrt{x + 1}}} \]
    2. div-inv38.0%

      \[\leadsto \color{blue}{\left(1 \cdot \sqrt{x + 1} - \sqrt{x} \cdot 1\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}}} \]
    3. *-un-lft-identity38.0%

      \[\leadsto \left(\color{blue}{\sqrt{x + 1}} - \sqrt{x} \cdot 1\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}} \]
    4. +-commutative38.0%

      \[\leadsto \left(\sqrt{\color{blue}{1 + x}} - \sqrt{x} \cdot 1\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}} \]
    5. *-rgt-identity38.0%

      \[\leadsto \left(\sqrt{1 + x} - \color{blue}{\sqrt{x}}\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}} \]
    6. metadata-eval38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\color{blue}{1 \cdot 1}}{\sqrt{x} \cdot \sqrt{x + 1}} \]
    7. frac-times38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \color{blue}{\left(\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x + 1}}\right)} \]
    8. associate-*l/38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \color{blue}{\frac{1 \cdot \frac{1}{\sqrt{x + 1}}}{\sqrt{x}}} \]
    9. *-un-lft-identity38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\color{blue}{\frac{1}{\sqrt{x + 1}}}}{\sqrt{x}} \]
    10. pow1/238.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\frac{1}{\color{blue}{{\left(x + 1\right)}^{0.5}}}}{\sqrt{x}} \]
    11. pow-flip38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\color{blue}{{\left(x + 1\right)}^{\left(-0.5\right)}}}{\sqrt{x}} \]
    12. +-commutative38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{{\color{blue}{\left(1 + x\right)}}^{\left(-0.5\right)}}{\sqrt{x}} \]
    13. metadata-eval38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{{\left(1 + x\right)}^{\color{blue}{-0.5}}}{\sqrt{x}} \]
  4. Applied egg-rr38.0%

    \[\leadsto \color{blue}{\left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{\sqrt{x}}} \]
  5. Step-by-step derivation
    1. *-commutative38.0%

      \[\leadsto \color{blue}{\frac{{\left(1 + x\right)}^{-0.5}}{\sqrt{x}} \cdot \left(\sqrt{1 + x} - \sqrt{x}\right)} \]
    2. /-rgt-identity38.0%

      \[\leadsto \frac{{\left(1 + x\right)}^{-0.5}}{\sqrt{x}} \cdot \color{blue}{\frac{\sqrt{1 + x} - \sqrt{x}}{1}} \]
    3. times-frac38.0%

      \[\leadsto \color{blue}{\frac{{\left(1 + x\right)}^{-0.5} \cdot \left(\sqrt{1 + x} - \sqrt{x}\right)}{\sqrt{x} \cdot 1}} \]
    4. *-commutative38.0%

      \[\leadsto \frac{\color{blue}{\left(\sqrt{1 + x} - \sqrt{x}\right) \cdot {\left(1 + x\right)}^{-0.5}}}{\sqrt{x} \cdot 1} \]
    5. times-frac38.0%

      \[\leadsto \color{blue}{\frac{\sqrt{1 + x} - \sqrt{x}}{\sqrt{x}} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1}} \]
    6. div-sub38.0%

      \[\leadsto \color{blue}{\left(\frac{\sqrt{1 + x}}{\sqrt{x}} - \frac{\sqrt{x}}{\sqrt{x}}\right)} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    7. sub-neg38.0%

      \[\leadsto \color{blue}{\left(\frac{\sqrt{1 + x}}{\sqrt{x}} + \left(-\frac{\sqrt{x}}{\sqrt{x}}\right)\right)} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    8. *-inverses38.0%

      \[\leadsto \left(\frac{\sqrt{1 + x}}{\sqrt{x}} + \left(-\color{blue}{1}\right)\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    9. metadata-eval38.0%

      \[\leadsto \left(\frac{\sqrt{1 + x}}{\sqrt{x}} + \color{blue}{-1}\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
  6. Simplified38.0%

    \[\leadsto \color{blue}{\left(\frac{\sqrt{1 + x}}{\sqrt{x}} + -1\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1}} \]
  7. Taylor expanded in x around inf 98.8%

    \[\leadsto \color{blue}{\left(0.5 \cdot \frac{1}{x} - 0.125 \cdot \frac{1}{{x}^{2}}\right)} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
  8. Step-by-step derivation
    1. associate-*r/98.8%

      \[\leadsto \left(\color{blue}{\frac{0.5 \cdot 1}{x}} - 0.125 \cdot \frac{1}{{x}^{2}}\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    2. metadata-eval98.8%

      \[\leadsto \left(\frac{\color{blue}{0.5}}{x} - 0.125 \cdot \frac{1}{{x}^{2}}\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    3. associate-*r/98.8%

      \[\leadsto \left(\frac{0.5}{x} - \color{blue}{\frac{0.125 \cdot 1}{{x}^{2}}}\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    4. metadata-eval98.8%

      \[\leadsto \left(\frac{0.5}{x} - \frac{\color{blue}{0.125}}{{x}^{2}}\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
  9. Simplified98.8%

    \[\leadsto \color{blue}{\left(\frac{0.5}{x} - \frac{0.125}{{x}^{2}}\right)} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
  10. Step-by-step derivation
    1. /-rgt-identity98.8%

      \[\leadsto \left(\frac{0.5}{x} - \frac{0.125}{{x}^{2}}\right) \cdot \color{blue}{{\left(1 + x\right)}^{-0.5}} \]
    2. metadata-eval98.8%

      \[\leadsto \left(\frac{0.5}{x} - \frac{0.125}{{x}^{2}}\right) \cdot {\left(1 + x\right)}^{\color{blue}{\left(\frac{-1}{2}\right)}} \]
    3. sqrt-pow298.6%

      \[\leadsto \left(\frac{0.5}{x} - \frac{0.125}{{x}^{2}}\right) \cdot \color{blue}{{\left(\sqrt{1 + x}\right)}^{-1}} \]
    4. +-commutative98.6%

      \[\leadsto \left(\frac{0.5}{x} - \frac{0.125}{{x}^{2}}\right) \cdot {\left(\sqrt{\color{blue}{x + 1}}\right)}^{-1} \]
    5. inv-pow98.6%

      \[\leadsto \left(\frac{0.5}{x} - \frac{0.125}{{x}^{2}}\right) \cdot \color{blue}{\frac{1}{\sqrt{x + 1}}} \]
    6. un-div-inv98.7%

      \[\leadsto \color{blue}{\frac{\frac{0.5}{x} - \frac{0.125}{{x}^{2}}}{\sqrt{x + 1}}} \]
    7. div-inv98.7%

      \[\leadsto \frac{\frac{0.5}{x} - \color{blue}{0.125 \cdot \frac{1}{{x}^{2}}}}{\sqrt{x + 1}} \]
    8. cancel-sign-sub-inv98.7%

      \[\leadsto \frac{\color{blue}{\frac{0.5}{x} + \left(-0.125\right) \cdot \frac{1}{{x}^{2}}}}{\sqrt{x + 1}} \]
    9. metadata-eval98.7%

      \[\leadsto \frac{\frac{0.5}{x} + \color{blue}{-0.125} \cdot \frac{1}{{x}^{2}}}{\sqrt{x + 1}} \]
    10. pow-flip98.7%

      \[\leadsto \frac{\frac{0.5}{x} + -0.125 \cdot \color{blue}{{x}^{\left(-2\right)}}}{\sqrt{x + 1}} \]
    11. metadata-eval98.7%

      \[\leadsto \frac{\frac{0.5}{x} + -0.125 \cdot {x}^{\color{blue}{-2}}}{\sqrt{x + 1}} \]
  11. Applied egg-rr98.7%

    \[\leadsto \color{blue}{\frac{\frac{0.5}{x} + -0.125 \cdot {x}^{-2}}{\sqrt{x + 1}}} \]
  12. Final simplification98.7%

    \[\leadsto \frac{\frac{0.5}{x} + -0.125 \cdot {x}^{-2}}{\sqrt{x + 1}} \]
  13. Add Preprocessing

Alternative 4: 97.9% accurate, 1.9× speedup?

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

\\
\frac{0.5}{x} \cdot {\left(x + 1\right)}^{-0.5}
\end{array}
Derivation
  1. Initial program 38.0%

    \[\frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. frac-sub38.0%

      \[\leadsto \color{blue}{\frac{1 \cdot \sqrt{x + 1} - \sqrt{x} \cdot 1}{\sqrt{x} \cdot \sqrt{x + 1}}} \]
    2. div-inv38.0%

      \[\leadsto \color{blue}{\left(1 \cdot \sqrt{x + 1} - \sqrt{x} \cdot 1\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}}} \]
    3. *-un-lft-identity38.0%

      \[\leadsto \left(\color{blue}{\sqrt{x + 1}} - \sqrt{x} \cdot 1\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}} \]
    4. +-commutative38.0%

      \[\leadsto \left(\sqrt{\color{blue}{1 + x}} - \sqrt{x} \cdot 1\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}} \]
    5. *-rgt-identity38.0%

      \[\leadsto \left(\sqrt{1 + x} - \color{blue}{\sqrt{x}}\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}} \]
    6. metadata-eval38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\color{blue}{1 \cdot 1}}{\sqrt{x} \cdot \sqrt{x + 1}} \]
    7. frac-times38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \color{blue}{\left(\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x + 1}}\right)} \]
    8. associate-*l/38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \color{blue}{\frac{1 \cdot \frac{1}{\sqrt{x + 1}}}{\sqrt{x}}} \]
    9. *-un-lft-identity38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\color{blue}{\frac{1}{\sqrt{x + 1}}}}{\sqrt{x}} \]
    10. pow1/238.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\frac{1}{\color{blue}{{\left(x + 1\right)}^{0.5}}}}{\sqrt{x}} \]
    11. pow-flip38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\color{blue}{{\left(x + 1\right)}^{\left(-0.5\right)}}}{\sqrt{x}} \]
    12. +-commutative38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{{\color{blue}{\left(1 + x\right)}}^{\left(-0.5\right)}}{\sqrt{x}} \]
    13. metadata-eval38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{{\left(1 + x\right)}^{\color{blue}{-0.5}}}{\sqrt{x}} \]
  4. Applied egg-rr38.0%

    \[\leadsto \color{blue}{\left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{\sqrt{x}}} \]
  5. Step-by-step derivation
    1. *-commutative38.0%

      \[\leadsto \color{blue}{\frac{{\left(1 + x\right)}^{-0.5}}{\sqrt{x}} \cdot \left(\sqrt{1 + x} - \sqrt{x}\right)} \]
    2. /-rgt-identity38.0%

      \[\leadsto \frac{{\left(1 + x\right)}^{-0.5}}{\sqrt{x}} \cdot \color{blue}{\frac{\sqrt{1 + x} - \sqrt{x}}{1}} \]
    3. times-frac38.0%

      \[\leadsto \color{blue}{\frac{{\left(1 + x\right)}^{-0.5} \cdot \left(\sqrt{1 + x} - \sqrt{x}\right)}{\sqrt{x} \cdot 1}} \]
    4. *-commutative38.0%

      \[\leadsto \frac{\color{blue}{\left(\sqrt{1 + x} - \sqrt{x}\right) \cdot {\left(1 + x\right)}^{-0.5}}}{\sqrt{x} \cdot 1} \]
    5. times-frac38.0%

      \[\leadsto \color{blue}{\frac{\sqrt{1 + x} - \sqrt{x}}{\sqrt{x}} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1}} \]
    6. div-sub38.0%

      \[\leadsto \color{blue}{\left(\frac{\sqrt{1 + x}}{\sqrt{x}} - \frac{\sqrt{x}}{\sqrt{x}}\right)} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    7. sub-neg38.0%

      \[\leadsto \color{blue}{\left(\frac{\sqrt{1 + x}}{\sqrt{x}} + \left(-\frac{\sqrt{x}}{\sqrt{x}}\right)\right)} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    8. *-inverses38.0%

      \[\leadsto \left(\frac{\sqrt{1 + x}}{\sqrt{x}} + \left(-\color{blue}{1}\right)\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    9. metadata-eval38.0%

      \[\leadsto \left(\frac{\sqrt{1 + x}}{\sqrt{x}} + \color{blue}{-1}\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
  6. Simplified38.0%

    \[\leadsto \color{blue}{\left(\frac{\sqrt{1 + x}}{\sqrt{x}} + -1\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1}} \]
  7. Taylor expanded in x around inf 97.2%

    \[\leadsto \color{blue}{\frac{0.5}{x}} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
  8. Final simplification97.2%

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

Alternative 5: 97.9% accurate, 2.0× speedup?

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

\\
\frac{\frac{0.5}{x}}{\sqrt{x + 1}}
\end{array}
Derivation
  1. Initial program 38.0%

    \[\frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. frac-sub38.0%

      \[\leadsto \color{blue}{\frac{1 \cdot \sqrt{x + 1} - \sqrt{x} \cdot 1}{\sqrt{x} \cdot \sqrt{x + 1}}} \]
    2. div-inv38.0%

      \[\leadsto \color{blue}{\left(1 \cdot \sqrt{x + 1} - \sqrt{x} \cdot 1\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}}} \]
    3. *-un-lft-identity38.0%

      \[\leadsto \left(\color{blue}{\sqrt{x + 1}} - \sqrt{x} \cdot 1\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}} \]
    4. +-commutative38.0%

      \[\leadsto \left(\sqrt{\color{blue}{1 + x}} - \sqrt{x} \cdot 1\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}} \]
    5. *-rgt-identity38.0%

      \[\leadsto \left(\sqrt{1 + x} - \color{blue}{\sqrt{x}}\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}} \]
    6. metadata-eval38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\color{blue}{1 \cdot 1}}{\sqrt{x} \cdot \sqrt{x + 1}} \]
    7. frac-times38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \color{blue}{\left(\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x + 1}}\right)} \]
    8. associate-*l/38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \color{blue}{\frac{1 \cdot \frac{1}{\sqrt{x + 1}}}{\sqrt{x}}} \]
    9. *-un-lft-identity38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\color{blue}{\frac{1}{\sqrt{x + 1}}}}{\sqrt{x}} \]
    10. pow1/238.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\frac{1}{\color{blue}{{\left(x + 1\right)}^{0.5}}}}{\sqrt{x}} \]
    11. pow-flip38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\color{blue}{{\left(x + 1\right)}^{\left(-0.5\right)}}}{\sqrt{x}} \]
    12. +-commutative38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{{\color{blue}{\left(1 + x\right)}}^{\left(-0.5\right)}}{\sqrt{x}} \]
    13. metadata-eval38.0%

      \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{{\left(1 + x\right)}^{\color{blue}{-0.5}}}{\sqrt{x}} \]
  4. Applied egg-rr38.0%

    \[\leadsto \color{blue}{\left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{\sqrt{x}}} \]
  5. Step-by-step derivation
    1. *-commutative38.0%

      \[\leadsto \color{blue}{\frac{{\left(1 + x\right)}^{-0.5}}{\sqrt{x}} \cdot \left(\sqrt{1 + x} - \sqrt{x}\right)} \]
    2. /-rgt-identity38.0%

      \[\leadsto \frac{{\left(1 + x\right)}^{-0.5}}{\sqrt{x}} \cdot \color{blue}{\frac{\sqrt{1 + x} - \sqrt{x}}{1}} \]
    3. times-frac38.0%

      \[\leadsto \color{blue}{\frac{{\left(1 + x\right)}^{-0.5} \cdot \left(\sqrt{1 + x} - \sqrt{x}\right)}{\sqrt{x} \cdot 1}} \]
    4. *-commutative38.0%

      \[\leadsto \frac{\color{blue}{\left(\sqrt{1 + x} - \sqrt{x}\right) \cdot {\left(1 + x\right)}^{-0.5}}}{\sqrt{x} \cdot 1} \]
    5. times-frac38.0%

      \[\leadsto \color{blue}{\frac{\sqrt{1 + x} - \sqrt{x}}{\sqrt{x}} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1}} \]
    6. div-sub38.0%

      \[\leadsto \color{blue}{\left(\frac{\sqrt{1 + x}}{\sqrt{x}} - \frac{\sqrt{x}}{\sqrt{x}}\right)} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    7. sub-neg38.0%

      \[\leadsto \color{blue}{\left(\frac{\sqrt{1 + x}}{\sqrt{x}} + \left(-\frac{\sqrt{x}}{\sqrt{x}}\right)\right)} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    8. *-inverses38.0%

      \[\leadsto \left(\frac{\sqrt{1 + x}}{\sqrt{x}} + \left(-\color{blue}{1}\right)\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    9. metadata-eval38.0%

      \[\leadsto \left(\frac{\sqrt{1 + x}}{\sqrt{x}} + \color{blue}{-1}\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
  6. Simplified38.0%

    \[\leadsto \color{blue}{\left(\frac{\sqrt{1 + x}}{\sqrt{x}} + -1\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1}} \]
  7. Taylor expanded in x around inf 37.0%

    \[\leadsto \left(\color{blue}{\left(1 + 0.5 \cdot \frac{1}{x}\right)} + -1\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
  8. Step-by-step derivation
    1. associate-*r/37.0%

      \[\leadsto \left(\left(1 + \color{blue}{\frac{0.5 \cdot 1}{x}}\right) + -1\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    2. metadata-eval37.0%

      \[\leadsto \left(\left(1 + \frac{\color{blue}{0.5}}{x}\right) + -1\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
  9. Simplified37.0%

    \[\leadsto \left(\color{blue}{\left(1 + \frac{0.5}{x}\right)} + -1\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
  10. Step-by-step derivation
    1. /-rgt-identity37.0%

      \[\leadsto \color{blue}{\frac{\left(\left(1 + \frac{0.5}{x}\right) + -1\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1}}{1}} \]
    2. clear-num37.0%

      \[\leadsto \color{blue}{\frac{1}{\frac{1}{\left(\left(1 + \frac{0.5}{x}\right) + -1\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1}}}} \]
    3. /-rgt-identity37.0%

      \[\leadsto \frac{1}{\frac{1}{\left(\left(1 + \frac{0.5}{x}\right) + -1\right) \cdot \color{blue}{{\left(1 + x\right)}^{-0.5}}}} \]
    4. metadata-eval37.0%

      \[\leadsto \frac{1}{\frac{1}{\left(\left(1 + \frac{0.5}{x}\right) + -1\right) \cdot {\left(1 + x\right)}^{\color{blue}{\left(\frac{-1}{2}\right)}}}} \]
    5. sqrt-pow237.0%

      \[\leadsto \frac{1}{\frac{1}{\left(\left(1 + \frac{0.5}{x}\right) + -1\right) \cdot \color{blue}{{\left(\sqrt{1 + x}\right)}^{-1}}}} \]
    6. +-commutative37.0%

      \[\leadsto \frac{1}{\frac{1}{\left(\left(1 + \frac{0.5}{x}\right) + -1\right) \cdot {\left(\sqrt{\color{blue}{x + 1}}\right)}^{-1}}} \]
    7. inv-pow37.0%

      \[\leadsto \frac{1}{\frac{1}{\left(\left(1 + \frac{0.5}{x}\right) + -1\right) \cdot \color{blue}{\frac{1}{\sqrt{x + 1}}}}} \]
    8. un-div-inv37.0%

      \[\leadsto \frac{1}{\frac{1}{\color{blue}{\frac{\left(1 + \frac{0.5}{x}\right) + -1}{\sqrt{x + 1}}}}} \]
    9. associate-+l+37.0%

      \[\leadsto \frac{1}{\frac{1}{\frac{\color{blue}{1 + \left(\frac{0.5}{x} + -1\right)}}{\sqrt{x + 1}}}} \]
  11. Applied egg-rr37.0%

    \[\leadsto \color{blue}{\frac{1}{\frac{1}{\frac{1 + \left(\frac{0.5}{x} + -1\right)}{\sqrt{x + 1}}}}} \]
  12. Step-by-step derivation
    1. remove-double-div37.0%

      \[\leadsto \color{blue}{\frac{1 + \left(\frac{0.5}{x} + -1\right)}{\sqrt{x + 1}}} \]
    2. +-commutative37.0%

      \[\leadsto \frac{1 + \color{blue}{\left(-1 + \frac{0.5}{x}\right)}}{\sqrt{x + 1}} \]
    3. associate-+r+97.2%

      \[\leadsto \frac{\color{blue}{\left(1 + -1\right) + \frac{0.5}{x}}}{\sqrt{x + 1}} \]
    4. metadata-eval97.2%

      \[\leadsto \frac{\color{blue}{0} + \frac{0.5}{x}}{\sqrt{x + 1}} \]
  13. Simplified97.2%

    \[\leadsto \color{blue}{\frac{0 + \frac{0.5}{x}}{\sqrt{x + 1}}} \]
  14. Final simplification97.2%

    \[\leadsto \frac{\frac{0.5}{x}}{\sqrt{x + 1}} \]
  15. Add Preprocessing

Alternative 6: 38.4% accurate, 26.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 6.4 \cdot 10^{+153}:\\ \;\;\;\;\frac{0.5}{x}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \end{array} \]
(FPCore (x) :precision binary64 (if (<= x 6.4e+153) (/ 0.5 x) 0.0))
double code(double x) {
	double tmp;
	if (x <= 6.4e+153) {
		tmp = 0.5 / x;
	} else {
		tmp = 0.0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 6.4d+153) then
        tmp = 0.5d0 / x
    else
        tmp = 0.0d0
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 6.4e+153) {
		tmp = 0.5 / x;
	} else {
		tmp = 0.0;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 6.4e+153:
		tmp = 0.5 / x
	else:
		tmp = 0.0
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 6.4e+153)
		tmp = Float64(0.5 / x);
	else
		tmp = 0.0;
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 6.4e+153)
		tmp = 0.5 / x;
	else
		tmp = 0.0;
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 6.4e+153], N[(0.5 / x), $MachinePrecision], 0.0]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 6.4 \cdot 10^{+153}:\\
\;\;\;\;\frac{0.5}{x}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 6.4000000000000003e153

    1. Initial program 11.7%

      \[\frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. frac-sub11.8%

        \[\leadsto \color{blue}{\frac{1 \cdot \sqrt{x + 1} - \sqrt{x} \cdot 1}{\sqrt{x} \cdot \sqrt{x + 1}}} \]
      2. div-inv11.8%

        \[\leadsto \color{blue}{\left(1 \cdot \sqrt{x + 1} - \sqrt{x} \cdot 1\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}}} \]
      3. *-un-lft-identity11.8%

        \[\leadsto \left(\color{blue}{\sqrt{x + 1}} - \sqrt{x} \cdot 1\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}} \]
      4. +-commutative11.8%

        \[\leadsto \left(\sqrt{\color{blue}{1 + x}} - \sqrt{x} \cdot 1\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}} \]
      5. *-rgt-identity11.8%

        \[\leadsto \left(\sqrt{1 + x} - \color{blue}{\sqrt{x}}\right) \cdot \frac{1}{\sqrt{x} \cdot \sqrt{x + 1}} \]
      6. metadata-eval11.8%

        \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\color{blue}{1 \cdot 1}}{\sqrt{x} \cdot \sqrt{x + 1}} \]
      7. frac-times11.8%

        \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \color{blue}{\left(\frac{1}{\sqrt{x}} \cdot \frac{1}{\sqrt{x + 1}}\right)} \]
      8. associate-*l/11.8%

        \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \color{blue}{\frac{1 \cdot \frac{1}{\sqrt{x + 1}}}{\sqrt{x}}} \]
      9. *-un-lft-identity11.8%

        \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\color{blue}{\frac{1}{\sqrt{x + 1}}}}{\sqrt{x}} \]
      10. pow1/211.8%

        \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\frac{1}{\color{blue}{{\left(x + 1\right)}^{0.5}}}}{\sqrt{x}} \]
      11. pow-flip11.8%

        \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{\color{blue}{{\left(x + 1\right)}^{\left(-0.5\right)}}}{\sqrt{x}} \]
      12. +-commutative11.8%

        \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{{\color{blue}{\left(1 + x\right)}}^{\left(-0.5\right)}}{\sqrt{x}} \]
      13. metadata-eval11.8%

        \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{{\left(1 + x\right)}^{\color{blue}{-0.5}}}{\sqrt{x}} \]
    4. Applied egg-rr11.8%

      \[\leadsto \color{blue}{\left(\sqrt{1 + x} - \sqrt{x}\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{\sqrt{x}}} \]
    5. Step-by-step derivation
      1. *-commutative11.8%

        \[\leadsto \color{blue}{\frac{{\left(1 + x\right)}^{-0.5}}{\sqrt{x}} \cdot \left(\sqrt{1 + x} - \sqrt{x}\right)} \]
      2. /-rgt-identity11.8%

        \[\leadsto \frac{{\left(1 + x\right)}^{-0.5}}{\sqrt{x}} \cdot \color{blue}{\frac{\sqrt{1 + x} - \sqrt{x}}{1}} \]
      3. times-frac11.8%

        \[\leadsto \color{blue}{\frac{{\left(1 + x\right)}^{-0.5} \cdot \left(\sqrt{1 + x} - \sqrt{x}\right)}{\sqrt{x} \cdot 1}} \]
      4. *-commutative11.8%

        \[\leadsto \frac{\color{blue}{\left(\sqrt{1 + x} - \sqrt{x}\right) \cdot {\left(1 + x\right)}^{-0.5}}}{\sqrt{x} \cdot 1} \]
      5. times-frac11.8%

        \[\leadsto \color{blue}{\frac{\sqrt{1 + x} - \sqrt{x}}{\sqrt{x}} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1}} \]
      6. div-sub11.7%

        \[\leadsto \color{blue}{\left(\frac{\sqrt{1 + x}}{\sqrt{x}} - \frac{\sqrt{x}}{\sqrt{x}}\right)} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
      7. sub-neg11.7%

        \[\leadsto \color{blue}{\left(\frac{\sqrt{1 + x}}{\sqrt{x}} + \left(-\frac{\sqrt{x}}{\sqrt{x}}\right)\right)} \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
      8. *-inverses11.7%

        \[\leadsto \left(\frac{\sqrt{1 + x}}{\sqrt{x}} + \left(-\color{blue}{1}\right)\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
      9. metadata-eval11.7%

        \[\leadsto \left(\frac{\sqrt{1 + x}}{\sqrt{x}} + \color{blue}{-1}\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    6. Simplified11.7%

      \[\leadsto \color{blue}{\left(\frac{\sqrt{1 + x}}{\sqrt{x}} + -1\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1}} \]
    7. Taylor expanded in x around inf 9.7%

      \[\leadsto \left(\color{blue}{\left(1 + 0.5 \cdot \frac{1}{x}\right)} + -1\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    8. Step-by-step derivation
      1. associate-*r/9.7%

        \[\leadsto \left(\left(1 + \color{blue}{\frac{0.5 \cdot 1}{x}}\right) + -1\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
      2. metadata-eval9.7%

        \[\leadsto \left(\left(1 + \frac{\color{blue}{0.5}}{x}\right) + -1\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    9. Simplified9.7%

      \[\leadsto \left(\color{blue}{\left(1 + \frac{0.5}{x}\right)} + -1\right) \cdot \frac{{\left(1 + x\right)}^{-0.5}}{1} \]
    10. Taylor expanded in x around 0 5.1%

      \[\leadsto \color{blue}{\left(0.1875 \cdot x + 0.5 \cdot \frac{1}{x}\right) - 0.25} \]
    11. Taylor expanded in x around 0 8.7%

      \[\leadsto \color{blue}{\frac{0.5}{x}} \]

    if 6.4000000000000003e153 < x

    1. Initial program 63.4%

      \[\frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf 63.4%

      \[\leadsto \color{blue}{0} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification36.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 6.4 \cdot 10^{+153}:\\ \;\;\;\;\frac{0.5}{x}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 36.4% 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 38.0%

    \[\frac{1}{\sqrt{x}} - \frac{1}{\sqrt{x + 1}} \]
  2. Add Preprocessing
  3. Taylor expanded in x around inf 34.3%

    \[\leadsto \color{blue}{0} \]
  4. Final simplification34.3%

    \[\leadsto 0 \]
  5. Add Preprocessing

Developer target: 98.2% 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 2024042 
(FPCore (x)
  :name "2isqrt (example 3.6)"
  :precision binary64
  :pre (and (> x 1.0) (< x 1e+308))

  :herbie-target
  (/ 1.0 (+ (* (+ x 1.0) (sqrt x)) (* x (sqrt (+ x 1.0)))))

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