ENA, Section 1.4, Exercise 4d

Percentage Accurate: 62.7% → 99.5%
Time: 10.0s
Alternatives: 8
Speedup: 0.9×

Specification

?
\[\left(0 \leq x \land x \leq 1000000000\right) \land \left(-1 \leq \varepsilon \land \varepsilon \leq 1\right)\]
\[\begin{array}{l} \\ x - \sqrt{x \cdot x - \varepsilon} \end{array} \]
(FPCore (x eps) :precision binary64 (- x (sqrt (- (* x x) eps))))
double code(double x, double eps) {
	return x - sqrt(((x * x) - eps));
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = x - sqrt(((x * x) - eps))
end function
public static double code(double x, double eps) {
	return x - Math.sqrt(((x * x) - eps));
}
def code(x, eps):
	return x - math.sqrt(((x * x) - eps))
function code(x, eps)
	return Float64(x - sqrt(Float64(Float64(x * x) - eps)))
end
function tmp = code(x, eps)
	tmp = x - sqrt(((x * x) - eps));
end
code[x_, eps_] := N[(x - N[Sqrt[N[(N[(x * x), $MachinePrecision] - eps), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x - \sqrt{x \cdot x - \varepsilon}
\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: 62.7% accurate, 1.0× speedup?

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

\\
x - \sqrt{x \cdot x - \varepsilon}
\end{array}

Alternative 1: 99.5% accurate, 0.5× speedup?

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

\\
\frac{\varepsilon}{x + \sqrt{{x}^{2} - \varepsilon}}
\end{array}
Derivation
  1. Initial program 63.3%

    \[x - \sqrt{x \cdot x - \varepsilon} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. pow1/263.3%

      \[\leadsto x - \color{blue}{{\left(x \cdot x - \varepsilon\right)}^{0.5}} \]
  4. Applied egg-rr63.0%

    \[\leadsto x - \color{blue}{{\left({\left({x}^{2} - \varepsilon\right)}^{0.25}\right)}^{0.5} \cdot {\left({\left({x}^{2} - \varepsilon\right)}^{0.75}\right)}^{0.5}} \]
  5. Step-by-step derivation
    1. unpow1/263.0%

      \[\leadsto x - \color{blue}{\sqrt{{\left({x}^{2} - \varepsilon\right)}^{0.25}}} \cdot {\left({\left({x}^{2} - \varepsilon\right)}^{0.75}\right)}^{0.5} \]
    2. unpow1/263.0%

      \[\leadsto x - \sqrt{{\left({x}^{2} - \varepsilon\right)}^{0.25}} \cdot \color{blue}{\sqrt{{\left({x}^{2} - \varepsilon\right)}^{0.75}}} \]
  6. Simplified63.0%

    \[\leadsto x - \color{blue}{\sqrt{{\left({x}^{2} - \varepsilon\right)}^{0.25}} \cdot \sqrt{{\left({x}^{2} - \varepsilon\right)}^{0.75}}} \]
  7. Step-by-step derivation
    1. flip--62.9%

      \[\leadsto \color{blue}{\frac{x \cdot x - \left(\sqrt{{\left({x}^{2} - \varepsilon\right)}^{0.25}} \cdot \sqrt{{\left({x}^{2} - \varepsilon\right)}^{0.75}}\right) \cdot \left(\sqrt{{\left({x}^{2} - \varepsilon\right)}^{0.25}} \cdot \sqrt{{\left({x}^{2} - \varepsilon\right)}^{0.75}}\right)}{x + \sqrt{{\left({x}^{2} - \varepsilon\right)}^{0.25}} \cdot \sqrt{{\left({x}^{2} - \varepsilon\right)}^{0.75}}}} \]
    2. div-inv62.8%

      \[\leadsto \color{blue}{\left(x \cdot x - \left(\sqrt{{\left({x}^{2} - \varepsilon\right)}^{0.25}} \cdot \sqrt{{\left({x}^{2} - \varepsilon\right)}^{0.75}}\right) \cdot \left(\sqrt{{\left({x}^{2} - \varepsilon\right)}^{0.25}} \cdot \sqrt{{\left({x}^{2} - \varepsilon\right)}^{0.75}}\right)\right) \cdot \frac{1}{x + \sqrt{{\left({x}^{2} - \varepsilon\right)}^{0.25}} \cdot \sqrt{{\left({x}^{2} - \varepsilon\right)}^{0.75}}}} \]
  8. Applied egg-rr62.8%

    \[\leadsto \color{blue}{\left({x}^{2} - \left({x}^{2} - \varepsilon\right)\right) \cdot \frac{1}{x + \sqrt{{x}^{2} - \varepsilon}}} \]
  9. Step-by-step derivation
    1. associate-*r/62.8%

      \[\leadsto \color{blue}{\frac{\left({x}^{2} - \left({x}^{2} - \varepsilon\right)\right) \cdot 1}{x + \sqrt{{x}^{2} - \varepsilon}}} \]
  10. Simplified99.5%

    \[\leadsto \color{blue}{\frac{\varepsilon}{x + \sqrt{{x}^{2} - \varepsilon}}} \]
  11. Add Preprocessing

Alternative 2: 98.6% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x - \sqrt{x \cdot x - \varepsilon} \leq -1 \cdot 10^{-151}:\\ \;\;\;\;\frac{\varepsilon}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{\varepsilon}{x + \left(x + \frac{\varepsilon}{x \cdot -2}\right)}\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (<= (- x (sqrt (- (* x x) eps))) -1e-151)
   (/ eps (+ x (hypot x (sqrt (- eps)))))
   (/ eps (+ x (+ x (/ eps (* x -2.0)))))))
double code(double x, double eps) {
	double tmp;
	if ((x - sqrt(((x * x) - eps))) <= -1e-151) {
		tmp = eps / (x + hypot(x, sqrt(-eps)));
	} else {
		tmp = eps / (x + (x + (eps / (x * -2.0))));
	}
	return tmp;
}
public static double code(double x, double eps) {
	double tmp;
	if ((x - Math.sqrt(((x * x) - eps))) <= -1e-151) {
		tmp = eps / (x + Math.hypot(x, Math.sqrt(-eps)));
	} else {
		tmp = eps / (x + (x + (eps / (x * -2.0))));
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if (x - math.sqrt(((x * x) - eps))) <= -1e-151:
		tmp = eps / (x + math.hypot(x, math.sqrt(-eps)))
	else:
		tmp = eps / (x + (x + (eps / (x * -2.0))))
	return tmp
function code(x, eps)
	tmp = 0.0
	if (Float64(x - sqrt(Float64(Float64(x * x) - eps))) <= -1e-151)
		tmp = Float64(eps / Float64(x + hypot(x, sqrt(Float64(-eps)))));
	else
		tmp = Float64(eps / Float64(x + Float64(x + Float64(eps / Float64(x * -2.0)))));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if ((x - sqrt(((x * x) - eps))) <= -1e-151)
		tmp = eps / (x + hypot(x, sqrt(-eps)));
	else
		tmp = eps / (x + (x + (eps / (x * -2.0))));
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[LessEqual[N[(x - N[Sqrt[N[(N[(x * x), $MachinePrecision] - eps), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], -1e-151], N[(eps / N[(x + N[Sqrt[x ^ 2 + N[Sqrt[(-eps)], $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(eps / N[(x + N[(x + N[(eps / N[(x * -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x - \sqrt{x \cdot x - \varepsilon} \leq -1 \cdot 10^{-151}:\\
\;\;\;\;\frac{\varepsilon}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}\\

\mathbf{else}:\\
\;\;\;\;\frac{\varepsilon}{x + \left(x + \frac{\varepsilon}{x \cdot -2}\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 x (sqrt.f64 (-.f64 (*.f64 x x) eps))) < -9.9999999999999994e-152

    1. Initial program 98.5%

      \[x - \sqrt{x \cdot x - \varepsilon} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. flip--98.3%

        \[\leadsto \color{blue}{\frac{x \cdot x - \sqrt{x \cdot x - \varepsilon} \cdot \sqrt{x \cdot x - \varepsilon}}{x + \sqrt{x \cdot x - \varepsilon}}} \]
      2. div-inv98.0%

        \[\leadsto \color{blue}{\left(x \cdot x - \sqrt{x \cdot x - \varepsilon} \cdot \sqrt{x \cdot x - \varepsilon}\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}}} \]
      3. add-sqr-sqrt97.7%

        \[\leadsto \left(x \cdot x - \color{blue}{\left(x \cdot x - \varepsilon\right)}\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      4. associate--r-99.2%

        \[\leadsto \color{blue}{\left(\left(x \cdot x - x \cdot x\right) + \varepsilon\right)} \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      5. pow299.2%

        \[\leadsto \left(\left(\color{blue}{{x}^{2}} - x \cdot x\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      6. pow299.2%

        \[\leadsto \left(\left({x}^{2} - \color{blue}{{x}^{2}}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      7. sub-neg99.2%

        \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{\color{blue}{x \cdot x + \left(-\varepsilon\right)}}} \]
      8. add-sqr-sqrt99.2%

        \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x + \color{blue}{\sqrt{-\varepsilon} \cdot \sqrt{-\varepsilon}}}} \]
      9. hypot-define99.2%

        \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \color{blue}{\mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
    4. Applied egg-rr99.2%

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

        \[\leadsto \color{blue}{\frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right)} \]
      2. +-inverses99.2%

        \[\leadsto \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \left(\color{blue}{0} + \varepsilon\right) \]
      3. +-lft-identity99.2%

        \[\leadsto \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \color{blue}{\varepsilon} \]
      4. associate-*l/99.2%

        \[\leadsto \color{blue}{\frac{1 \cdot \varepsilon}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
      5. *-lft-identity99.2%

        \[\leadsto \frac{\color{blue}{\varepsilon}}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \]
    6. Simplified99.2%

      \[\leadsto \color{blue}{\frac{\varepsilon}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]

    if -9.9999999999999994e-152 < (-.f64 x (sqrt.f64 (-.f64 (*.f64 x x) eps)))

    1. Initial program 7.4%

      \[x - \sqrt{x \cdot x - \varepsilon} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. flip--7.4%

        \[\leadsto \color{blue}{\frac{x \cdot x - \sqrt{x \cdot x - \varepsilon} \cdot \sqrt{x \cdot x - \varepsilon}}{x + \sqrt{x \cdot x - \varepsilon}}} \]
      2. div-inv7.4%

        \[\leadsto \color{blue}{\left(x \cdot x - \sqrt{x \cdot x - \varepsilon} \cdot \sqrt{x \cdot x - \varepsilon}\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}}} \]
      3. add-sqr-sqrt7.5%

        \[\leadsto \left(x \cdot x - \color{blue}{\left(x \cdot x - \varepsilon\right)}\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      4. associate--r-99.5%

        \[\leadsto \color{blue}{\left(\left(x \cdot x - x \cdot x\right) + \varepsilon\right)} \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      5. pow299.5%

        \[\leadsto \left(\left(\color{blue}{{x}^{2}} - x \cdot x\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      6. pow299.5%

        \[\leadsto \left(\left({x}^{2} - \color{blue}{{x}^{2}}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      7. sub-neg99.5%

        \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{\color{blue}{x \cdot x + \left(-\varepsilon\right)}}} \]
      8. add-sqr-sqrt49.2%

        \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x + \color{blue}{\sqrt{-\varepsilon} \cdot \sqrt{-\varepsilon}}}} \]
      9. hypot-define49.2%

        \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \color{blue}{\mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
    4. Applied egg-rr49.2%

      \[\leadsto \color{blue}{\left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
    5. Step-by-step derivation
      1. *-commutative49.2%

        \[\leadsto \color{blue}{\frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right)} \]
      2. +-inverses49.2%

        \[\leadsto \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \left(\color{blue}{0} + \varepsilon\right) \]
      3. +-lft-identity49.2%

        \[\leadsto \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \color{blue}{\varepsilon} \]
      4. associate-*l/49.5%

        \[\leadsto \color{blue}{\frac{1 \cdot \varepsilon}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
      5. *-lft-identity49.5%

        \[\leadsto \frac{\color{blue}{\varepsilon}}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \]
    6. Simplified49.5%

      \[\leadsto \color{blue}{\frac{\varepsilon}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
    7. Taylor expanded in eps around 0 0.0%

      \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(x + 0.5 \cdot \frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x}\right)}} \]
    8. Step-by-step derivation
      1. +-commutative0.0%

        \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(0.5 \cdot \frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x} + x\right)}} \]
      2. *-commutative0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x} \cdot 0.5} + x\right)} \]
      3. associate-/l*0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(\varepsilon \cdot \frac{{\left(\sqrt{-1}\right)}^{2}}{x}\right)} \cdot 0.5 + x\right)} \]
      4. associate-*r*0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\varepsilon \cdot \left(\frac{{\left(\sqrt{-1}\right)}^{2}}{x} \cdot 0.5\right)} + x\right)} \]
      5. *-commutative0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\left(0.5 \cdot \frac{{\left(\sqrt{-1}\right)}^{2}}{x}\right)} + x\right)} \]
      6. associate-*r/0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\frac{0.5 \cdot {\left(\sqrt{-1}\right)}^{2}}{x}} + x\right)} \]
      7. unpow20.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{0.5 \cdot \color{blue}{\left(\sqrt{-1} \cdot \sqrt{-1}\right)}}{x} + x\right)} \]
      8. rem-square-sqrt98.9%

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

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{\color{blue}{-0.5}}{x} + x\right)} \]
      10. metadata-eval98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{\color{blue}{-0.5}}{x} + x\right)} \]
      11. distribute-neg-frac98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\left(-\frac{0.5}{x}\right)} + x\right)} \]
      12. distribute-rgt-neg-in98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(-\varepsilon \cdot \frac{0.5}{x}\right)} + x\right)} \]
      13. *-commutative98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\left(-\color{blue}{\frac{0.5}{x} \cdot \varepsilon}\right) + x\right)} \]
      14. distribute-lft-neg-in98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(-\frac{0.5}{x}\right) \cdot \varepsilon} + x\right)} \]
      15. fma-define98.9%

        \[\leadsto \frac{\varepsilon}{x + \color{blue}{\mathsf{fma}\left(-\frac{0.5}{x}, \varepsilon, x\right)}} \]
      16. distribute-neg-frac98.9%

        \[\leadsto \frac{\varepsilon}{x + \mathsf{fma}\left(\color{blue}{\frac{-0.5}{x}}, \varepsilon, x\right)} \]
      17. metadata-eval98.9%

        \[\leadsto \frac{\varepsilon}{x + \mathsf{fma}\left(\frac{\color{blue}{-0.5}}{x}, \varepsilon, x\right)} \]
    9. Simplified98.9%

      \[\leadsto \frac{\varepsilon}{x + \color{blue}{\mathsf{fma}\left(\frac{-0.5}{x}, \varepsilon, x\right)}} \]
    10. Step-by-step derivation
      1. fma-undefine98.9%

        \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(\frac{-0.5}{x} \cdot \varepsilon + x\right)}} \]
      2. clear-num98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\frac{1}{\frac{x}{-0.5}}} \cdot \varepsilon + x\right)} \]
      3. associate-*l/98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\frac{1 \cdot \varepsilon}{\frac{x}{-0.5}}} + x\right)} \]
      4. *-un-lft-identity98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\frac{\color{blue}{\varepsilon}}{\frac{x}{-0.5}} + x\right)} \]
      5. div-inv98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\frac{\varepsilon}{\color{blue}{x \cdot \frac{1}{-0.5}}} + x\right)} \]
      6. metadata-eval98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\frac{\varepsilon}{x \cdot \color{blue}{-2}} + x\right)} \]
    11. Applied egg-rr98.9%

      \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(\frac{\varepsilon}{x \cdot -2} + x\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x - \sqrt{x \cdot x - \varepsilon} \leq -1 \cdot 10^{-151}:\\ \;\;\;\;\frac{\varepsilon}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{\varepsilon}{x + \left(x + \frac{\varepsilon}{x \cdot -2}\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 98.1% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := x - \sqrt{x \cdot x - \varepsilon}\\ \mathbf{if}\;t\_0 \leq -1 \cdot 10^{-151}:\\ \;\;\;\;t\_0\\ \mathbf{else}:\\ \;\;\;\;\frac{\varepsilon}{x + \left(x + \frac{\varepsilon}{x \cdot -2}\right)}\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (- x (sqrt (- (* x x) eps)))))
   (if (<= t_0 -1e-151) t_0 (/ eps (+ x (+ x (/ eps (* x -2.0))))))))
double code(double x, double eps) {
	double t_0 = x - sqrt(((x * x) - eps));
	double tmp;
	if (t_0 <= -1e-151) {
		tmp = t_0;
	} else {
		tmp = eps / (x + (x + (eps / (x * -2.0))));
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: t_0
    real(8) :: tmp
    t_0 = x - sqrt(((x * x) - eps))
    if (t_0 <= (-1d-151)) then
        tmp = t_0
    else
        tmp = eps / (x + (x + (eps / (x * (-2.0d0)))))
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double t_0 = x - Math.sqrt(((x * x) - eps));
	double tmp;
	if (t_0 <= -1e-151) {
		tmp = t_0;
	} else {
		tmp = eps / (x + (x + (eps / (x * -2.0))));
	}
	return tmp;
}
def code(x, eps):
	t_0 = x - math.sqrt(((x * x) - eps))
	tmp = 0
	if t_0 <= -1e-151:
		tmp = t_0
	else:
		tmp = eps / (x + (x + (eps / (x * -2.0))))
	return tmp
function code(x, eps)
	t_0 = Float64(x - sqrt(Float64(Float64(x * x) - eps)))
	tmp = 0.0
	if (t_0 <= -1e-151)
		tmp = t_0;
	else
		tmp = Float64(eps / Float64(x + Float64(x + Float64(eps / Float64(x * -2.0)))));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	t_0 = x - sqrt(((x * x) - eps));
	tmp = 0.0;
	if (t_0 <= -1e-151)
		tmp = t_0;
	else
		tmp = eps / (x + (x + (eps / (x * -2.0))));
	end
	tmp_2 = tmp;
end
code[x_, eps_] := Block[{t$95$0 = N[(x - N[Sqrt[N[(N[(x * x), $MachinePrecision] - eps), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -1e-151], t$95$0, N[(eps / N[(x + N[(x + N[(eps / N[(x * -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := x - \sqrt{x \cdot x - \varepsilon}\\
\mathbf{if}\;t\_0 \leq -1 \cdot 10^{-151}:\\
\;\;\;\;t\_0\\

\mathbf{else}:\\
\;\;\;\;\frac{\varepsilon}{x + \left(x + \frac{\varepsilon}{x \cdot -2}\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 x (sqrt.f64 (-.f64 (*.f64 x x) eps))) < -9.9999999999999994e-152

    1. Initial program 98.5%

      \[x - \sqrt{x \cdot x - \varepsilon} \]
    2. Add Preprocessing

    if -9.9999999999999994e-152 < (-.f64 x (sqrt.f64 (-.f64 (*.f64 x x) eps)))

    1. Initial program 7.4%

      \[x - \sqrt{x \cdot x - \varepsilon} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. flip--7.4%

        \[\leadsto \color{blue}{\frac{x \cdot x - \sqrt{x \cdot x - \varepsilon} \cdot \sqrt{x \cdot x - \varepsilon}}{x + \sqrt{x \cdot x - \varepsilon}}} \]
      2. div-inv7.4%

        \[\leadsto \color{blue}{\left(x \cdot x - \sqrt{x \cdot x - \varepsilon} \cdot \sqrt{x \cdot x - \varepsilon}\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}}} \]
      3. add-sqr-sqrt7.5%

        \[\leadsto \left(x \cdot x - \color{blue}{\left(x \cdot x - \varepsilon\right)}\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      4. associate--r-99.5%

        \[\leadsto \color{blue}{\left(\left(x \cdot x - x \cdot x\right) + \varepsilon\right)} \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      5. pow299.5%

        \[\leadsto \left(\left(\color{blue}{{x}^{2}} - x \cdot x\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      6. pow299.5%

        \[\leadsto \left(\left({x}^{2} - \color{blue}{{x}^{2}}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      7. sub-neg99.5%

        \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{\color{blue}{x \cdot x + \left(-\varepsilon\right)}}} \]
      8. add-sqr-sqrt49.2%

        \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x + \color{blue}{\sqrt{-\varepsilon} \cdot \sqrt{-\varepsilon}}}} \]
      9. hypot-define49.2%

        \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \color{blue}{\mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
    4. Applied egg-rr49.2%

      \[\leadsto \color{blue}{\left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
    5. Step-by-step derivation
      1. *-commutative49.2%

        \[\leadsto \color{blue}{\frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right)} \]
      2. +-inverses49.2%

        \[\leadsto \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \left(\color{blue}{0} + \varepsilon\right) \]
      3. +-lft-identity49.2%

        \[\leadsto \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \color{blue}{\varepsilon} \]
      4. associate-*l/49.5%

        \[\leadsto \color{blue}{\frac{1 \cdot \varepsilon}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
      5. *-lft-identity49.5%

        \[\leadsto \frac{\color{blue}{\varepsilon}}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \]
    6. Simplified49.5%

      \[\leadsto \color{blue}{\frac{\varepsilon}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
    7. Taylor expanded in eps around 0 0.0%

      \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(x + 0.5 \cdot \frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x}\right)}} \]
    8. Step-by-step derivation
      1. +-commutative0.0%

        \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(0.5 \cdot \frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x} + x\right)}} \]
      2. *-commutative0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x} \cdot 0.5} + x\right)} \]
      3. associate-/l*0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(\varepsilon \cdot \frac{{\left(\sqrt{-1}\right)}^{2}}{x}\right)} \cdot 0.5 + x\right)} \]
      4. associate-*r*0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\varepsilon \cdot \left(\frac{{\left(\sqrt{-1}\right)}^{2}}{x} \cdot 0.5\right)} + x\right)} \]
      5. *-commutative0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\left(0.5 \cdot \frac{{\left(\sqrt{-1}\right)}^{2}}{x}\right)} + x\right)} \]
      6. associate-*r/0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\frac{0.5 \cdot {\left(\sqrt{-1}\right)}^{2}}{x}} + x\right)} \]
      7. unpow20.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{0.5 \cdot \color{blue}{\left(\sqrt{-1} \cdot \sqrt{-1}\right)}}{x} + x\right)} \]
      8. rem-square-sqrt98.9%

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

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{\color{blue}{-0.5}}{x} + x\right)} \]
      10. metadata-eval98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{\color{blue}{-0.5}}{x} + x\right)} \]
      11. distribute-neg-frac98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\left(-\frac{0.5}{x}\right)} + x\right)} \]
      12. distribute-rgt-neg-in98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(-\varepsilon \cdot \frac{0.5}{x}\right)} + x\right)} \]
      13. *-commutative98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\left(-\color{blue}{\frac{0.5}{x} \cdot \varepsilon}\right) + x\right)} \]
      14. distribute-lft-neg-in98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(-\frac{0.5}{x}\right) \cdot \varepsilon} + x\right)} \]
      15. fma-define98.9%

        \[\leadsto \frac{\varepsilon}{x + \color{blue}{\mathsf{fma}\left(-\frac{0.5}{x}, \varepsilon, x\right)}} \]
      16. distribute-neg-frac98.9%

        \[\leadsto \frac{\varepsilon}{x + \mathsf{fma}\left(\color{blue}{\frac{-0.5}{x}}, \varepsilon, x\right)} \]
      17. metadata-eval98.9%

        \[\leadsto \frac{\varepsilon}{x + \mathsf{fma}\left(\frac{\color{blue}{-0.5}}{x}, \varepsilon, x\right)} \]
    9. Simplified98.9%

      \[\leadsto \frac{\varepsilon}{x + \color{blue}{\mathsf{fma}\left(\frac{-0.5}{x}, \varepsilon, x\right)}} \]
    10. Step-by-step derivation
      1. fma-undefine98.9%

        \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(\frac{-0.5}{x} \cdot \varepsilon + x\right)}} \]
      2. clear-num98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\frac{1}{\frac{x}{-0.5}}} \cdot \varepsilon + x\right)} \]
      3. associate-*l/98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\frac{1 \cdot \varepsilon}{\frac{x}{-0.5}}} + x\right)} \]
      4. *-un-lft-identity98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\frac{\color{blue}{\varepsilon}}{\frac{x}{-0.5}} + x\right)} \]
      5. div-inv98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\frac{\varepsilon}{\color{blue}{x \cdot \frac{1}{-0.5}}} + x\right)} \]
      6. metadata-eval98.9%

        \[\leadsto \frac{\varepsilon}{x + \left(\frac{\varepsilon}{x \cdot \color{blue}{-2}} + x\right)} \]
    11. Applied egg-rr98.9%

      \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(\frac{\varepsilon}{x \cdot -2} + x\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x - \sqrt{x \cdot x - \varepsilon} \leq -1 \cdot 10^{-151}:\\ \;\;\;\;x - \sqrt{x \cdot x - \varepsilon}\\ \mathbf{else}:\\ \;\;\;\;\frac{\varepsilon}{x + \left(x + \frac{\varepsilon}{x \cdot -2}\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 85.4% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := x - \sqrt{-\varepsilon}\\ \mathbf{if}\;x \leq 9 \cdot 10^{-121}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 4.8 \cdot 10^{-89}:\\ \;\;\;\;\frac{\varepsilon}{x + \left(x + \frac{\varepsilon}{x \cdot -2}\right)}\\ \mathbf{elif}\;x \leq 2.05 \cdot 10^{-81}:\\ \;\;\;\;t\_0\\ \mathbf{else}:\\ \;\;\;\;\frac{\varepsilon}{-0.5 \cdot \frac{\varepsilon}{x} + x \cdot 2}\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (- x (sqrt (- eps)))))
   (if (<= x 9e-121)
     t_0
     (if (<= x 4.8e-89)
       (/ eps (+ x (+ x (/ eps (* x -2.0)))))
       (if (<= x 2.05e-81) t_0 (/ eps (+ (* -0.5 (/ eps x)) (* x 2.0))))))))
double code(double x, double eps) {
	double t_0 = x - sqrt(-eps);
	double tmp;
	if (x <= 9e-121) {
		tmp = t_0;
	} else if (x <= 4.8e-89) {
		tmp = eps / (x + (x + (eps / (x * -2.0))));
	} else if (x <= 2.05e-81) {
		tmp = t_0;
	} else {
		tmp = eps / ((-0.5 * (eps / x)) + (x * 2.0));
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: t_0
    real(8) :: tmp
    t_0 = x - sqrt(-eps)
    if (x <= 9d-121) then
        tmp = t_0
    else if (x <= 4.8d-89) then
        tmp = eps / (x + (x + (eps / (x * (-2.0d0)))))
    else if (x <= 2.05d-81) then
        tmp = t_0
    else
        tmp = eps / (((-0.5d0) * (eps / x)) + (x * 2.0d0))
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double t_0 = x - Math.sqrt(-eps);
	double tmp;
	if (x <= 9e-121) {
		tmp = t_0;
	} else if (x <= 4.8e-89) {
		tmp = eps / (x + (x + (eps / (x * -2.0))));
	} else if (x <= 2.05e-81) {
		tmp = t_0;
	} else {
		tmp = eps / ((-0.5 * (eps / x)) + (x * 2.0));
	}
	return tmp;
}
def code(x, eps):
	t_0 = x - math.sqrt(-eps)
	tmp = 0
	if x <= 9e-121:
		tmp = t_0
	elif x <= 4.8e-89:
		tmp = eps / (x + (x + (eps / (x * -2.0))))
	elif x <= 2.05e-81:
		tmp = t_0
	else:
		tmp = eps / ((-0.5 * (eps / x)) + (x * 2.0))
	return tmp
function code(x, eps)
	t_0 = Float64(x - sqrt(Float64(-eps)))
	tmp = 0.0
	if (x <= 9e-121)
		tmp = t_0;
	elseif (x <= 4.8e-89)
		tmp = Float64(eps / Float64(x + Float64(x + Float64(eps / Float64(x * -2.0)))));
	elseif (x <= 2.05e-81)
		tmp = t_0;
	else
		tmp = Float64(eps / Float64(Float64(-0.5 * Float64(eps / x)) + Float64(x * 2.0)));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	t_0 = x - sqrt(-eps);
	tmp = 0.0;
	if (x <= 9e-121)
		tmp = t_0;
	elseif (x <= 4.8e-89)
		tmp = eps / (x + (x + (eps / (x * -2.0))));
	elseif (x <= 2.05e-81)
		tmp = t_0;
	else
		tmp = eps / ((-0.5 * (eps / x)) + (x * 2.0));
	end
	tmp_2 = tmp;
end
code[x_, eps_] := Block[{t$95$0 = N[(x - N[Sqrt[(-eps)], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[x, 9e-121], t$95$0, If[LessEqual[x, 4.8e-89], N[(eps / N[(x + N[(x + N[(eps / N[(x * -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 2.05e-81], t$95$0, N[(eps / N[(N[(-0.5 * N[(eps / x), $MachinePrecision]), $MachinePrecision] + N[(x * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := x - \sqrt{-\varepsilon}\\
\mathbf{if}\;x \leq 9 \cdot 10^{-121}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;x \leq 4.8 \cdot 10^{-89}:\\
\;\;\;\;\frac{\varepsilon}{x + \left(x + \frac{\varepsilon}{x \cdot -2}\right)}\\

\mathbf{elif}\;x \leq 2.05 \cdot 10^{-81}:\\
\;\;\;\;t\_0\\

\mathbf{else}:\\
\;\;\;\;\frac{\varepsilon}{-0.5 \cdot \frac{\varepsilon}{x} + x \cdot 2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < 9.0000000000000007e-121 or 4.80000000000000032e-89 < x < 2.04999999999999992e-81

    1. Initial program 97.9%

      \[x - \sqrt{x \cdot x - \varepsilon} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 96.4%

      \[\leadsto x - \sqrt{\color{blue}{-1 \cdot \varepsilon}} \]
    4. Step-by-step derivation
      1. neg-mul-196.4%

        \[\leadsto x - \sqrt{\color{blue}{-\varepsilon}} \]
    5. Simplified96.4%

      \[\leadsto x - \sqrt{\color{blue}{-\varepsilon}} \]

    if 9.0000000000000007e-121 < x < 4.80000000000000032e-89

    1. Initial program 39.3%

      \[x - \sqrt{x \cdot x - \varepsilon} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. flip--39.3%

        \[\leadsto \color{blue}{\frac{x \cdot x - \sqrt{x \cdot x - \varepsilon} \cdot \sqrt{x \cdot x - \varepsilon}}{x + \sqrt{x \cdot x - \varepsilon}}} \]
      2. div-inv39.3%

        \[\leadsto \color{blue}{\left(x \cdot x - \sqrt{x \cdot x - \varepsilon} \cdot \sqrt{x \cdot x - \varepsilon}\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}}} \]
      3. add-sqr-sqrt39.2%

        \[\leadsto \left(x \cdot x - \color{blue}{\left(x \cdot x - \varepsilon\right)}\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      4. associate--r-99.5%

        \[\leadsto \color{blue}{\left(\left(x \cdot x - x \cdot x\right) + \varepsilon\right)} \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      5. pow299.5%

        \[\leadsto \left(\left(\color{blue}{{x}^{2}} - x \cdot x\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      6. pow299.5%

        \[\leadsto \left(\left({x}^{2} - \color{blue}{{x}^{2}}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      7. sub-neg99.5%

        \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{\color{blue}{x \cdot x + \left(-\varepsilon\right)}}} \]
      8. add-sqr-sqrt65.1%

        \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x + \color{blue}{\sqrt{-\varepsilon} \cdot \sqrt{-\varepsilon}}}} \]
      9. hypot-define65.1%

        \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \color{blue}{\mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
    4. Applied egg-rr65.1%

      \[\leadsto \color{blue}{\left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
    5. Step-by-step derivation
      1. *-commutative65.1%

        \[\leadsto \color{blue}{\frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right)} \]
      2. +-inverses65.1%

        \[\leadsto \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \left(\color{blue}{0} + \varepsilon\right) \]
      3. +-lft-identity65.1%

        \[\leadsto \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \color{blue}{\varepsilon} \]
      4. associate-*l/65.1%

        \[\leadsto \color{blue}{\frac{1 \cdot \varepsilon}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
      5. *-lft-identity65.1%

        \[\leadsto \frac{\color{blue}{\varepsilon}}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \]
    6. Simplified65.1%

      \[\leadsto \color{blue}{\frac{\varepsilon}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
    7. Taylor expanded in eps around 0 0.0%

      \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(x + 0.5 \cdot \frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x}\right)}} \]
    8. Step-by-step derivation
      1. +-commutative0.0%

        \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(0.5 \cdot \frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x} + x\right)}} \]
      2. *-commutative0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x} \cdot 0.5} + x\right)} \]
      3. associate-/l*0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(\varepsilon \cdot \frac{{\left(\sqrt{-1}\right)}^{2}}{x}\right)} \cdot 0.5 + x\right)} \]
      4. associate-*r*0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\varepsilon \cdot \left(\frac{{\left(\sqrt{-1}\right)}^{2}}{x} \cdot 0.5\right)} + x\right)} \]
      5. *-commutative0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\left(0.5 \cdot \frac{{\left(\sqrt{-1}\right)}^{2}}{x}\right)} + x\right)} \]
      6. associate-*r/0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\frac{0.5 \cdot {\left(\sqrt{-1}\right)}^{2}}{x}} + x\right)} \]
      7. unpow20.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{0.5 \cdot \color{blue}{\left(\sqrt{-1} \cdot \sqrt{-1}\right)}}{x} + x\right)} \]
      8. rem-square-sqrt70.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{0.5 \cdot \color{blue}{-1}}{x} + x\right)} \]
      9. metadata-eval70.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{\color{blue}{-0.5}}{x} + x\right)} \]
      10. metadata-eval70.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{\color{blue}{-0.5}}{x} + x\right)} \]
      11. distribute-neg-frac70.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\left(-\frac{0.5}{x}\right)} + x\right)} \]
      12. distribute-rgt-neg-in70.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(-\varepsilon \cdot \frac{0.5}{x}\right)} + x\right)} \]
      13. *-commutative70.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\left(-\color{blue}{\frac{0.5}{x} \cdot \varepsilon}\right) + x\right)} \]
      14. distribute-lft-neg-in70.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(-\frac{0.5}{x}\right) \cdot \varepsilon} + x\right)} \]
      15. fma-define70.0%

        \[\leadsto \frac{\varepsilon}{x + \color{blue}{\mathsf{fma}\left(-\frac{0.5}{x}, \varepsilon, x\right)}} \]
      16. distribute-neg-frac70.0%

        \[\leadsto \frac{\varepsilon}{x + \mathsf{fma}\left(\color{blue}{\frac{-0.5}{x}}, \varepsilon, x\right)} \]
      17. metadata-eval70.0%

        \[\leadsto \frac{\varepsilon}{x + \mathsf{fma}\left(\frac{\color{blue}{-0.5}}{x}, \varepsilon, x\right)} \]
    9. Simplified70.0%

      \[\leadsto \frac{\varepsilon}{x + \color{blue}{\mathsf{fma}\left(\frac{-0.5}{x}, \varepsilon, x\right)}} \]
    10. Step-by-step derivation
      1. fma-undefine70.0%

        \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(\frac{-0.5}{x} \cdot \varepsilon + x\right)}} \]
      2. clear-num70.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\frac{1}{\frac{x}{-0.5}}} \cdot \varepsilon + x\right)} \]
      3. associate-*l/70.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\frac{1 \cdot \varepsilon}{\frac{x}{-0.5}}} + x\right)} \]
      4. *-un-lft-identity70.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\frac{\color{blue}{\varepsilon}}{\frac{x}{-0.5}} + x\right)} \]
      5. div-inv70.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\frac{\varepsilon}{\color{blue}{x \cdot \frac{1}{-0.5}}} + x\right)} \]
      6. metadata-eval70.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\frac{\varepsilon}{x \cdot \color{blue}{-2}} + x\right)} \]
    11. Applied egg-rr70.0%

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

    if 2.04999999999999992e-81 < x

    1. Initial program 19.7%

      \[x - \sqrt{x \cdot x - \varepsilon} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. flip--19.7%

        \[\leadsto \color{blue}{\frac{x \cdot x - \sqrt{x \cdot x - \varepsilon} \cdot \sqrt{x \cdot x - \varepsilon}}{x + \sqrt{x \cdot x - \varepsilon}}} \]
      2. div-inv19.7%

        \[\leadsto \color{blue}{\left(x \cdot x - \sqrt{x \cdot x - \varepsilon} \cdot \sqrt{x \cdot x - \varepsilon}\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}}} \]
      3. add-sqr-sqrt19.8%

        \[\leadsto \left(x \cdot x - \color{blue}{\left(x \cdot x - \varepsilon\right)}\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      4. associate--r-99.5%

        \[\leadsto \color{blue}{\left(\left(x \cdot x - x \cdot x\right) + \varepsilon\right)} \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      5. pow299.5%

        \[\leadsto \left(\left(\color{blue}{{x}^{2}} - x \cdot x\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      6. pow299.5%

        \[\leadsto \left(\left({x}^{2} - \color{blue}{{x}^{2}}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
      7. sub-neg99.5%

        \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{\color{blue}{x \cdot x + \left(-\varepsilon\right)}}} \]
      8. add-sqr-sqrt59.2%

        \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x + \color{blue}{\sqrt{-\varepsilon} \cdot \sqrt{-\varepsilon}}}} \]
      9. hypot-define59.2%

        \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \color{blue}{\mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
    4. Applied egg-rr59.2%

      \[\leadsto \color{blue}{\left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
    5. Step-by-step derivation
      1. *-commutative59.2%

        \[\leadsto \color{blue}{\frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right)} \]
      2. +-inverses59.2%

        \[\leadsto \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \left(\color{blue}{0} + \varepsilon\right) \]
      3. +-lft-identity59.2%

        \[\leadsto \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \color{blue}{\varepsilon} \]
      4. associate-*l/59.4%

        \[\leadsto \color{blue}{\frac{1 \cdot \varepsilon}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
      5. *-lft-identity59.4%

        \[\leadsto \frac{\color{blue}{\varepsilon}}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \]
    6. Simplified59.4%

      \[\leadsto \color{blue}{\frac{\varepsilon}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
    7. Taylor expanded in eps around 0 0.0%

      \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(x + 0.5 \cdot \frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x}\right)}} \]
    8. Step-by-step derivation
      1. +-commutative0.0%

        \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(0.5 \cdot \frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x} + x\right)}} \]
      2. *-commutative0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x} \cdot 0.5} + x\right)} \]
      3. associate-/l*0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(\varepsilon \cdot \frac{{\left(\sqrt{-1}\right)}^{2}}{x}\right)} \cdot 0.5 + x\right)} \]
      4. associate-*r*0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\varepsilon \cdot \left(\frac{{\left(\sqrt{-1}\right)}^{2}}{x} \cdot 0.5\right)} + x\right)} \]
      5. *-commutative0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\left(0.5 \cdot \frac{{\left(\sqrt{-1}\right)}^{2}}{x}\right)} + x\right)} \]
      6. associate-*r/0.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\frac{0.5 \cdot {\left(\sqrt{-1}\right)}^{2}}{x}} + x\right)} \]
      7. unpow20.0%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{0.5 \cdot \color{blue}{\left(\sqrt{-1} \cdot \sqrt{-1}\right)}}{x} + x\right)} \]
      8. rem-square-sqrt87.3%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{0.5 \cdot \color{blue}{-1}}{x} + x\right)} \]
      9. metadata-eval87.3%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{\color{blue}{-0.5}}{x} + x\right)} \]
      10. metadata-eval87.3%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{\color{blue}{-0.5}}{x} + x\right)} \]
      11. distribute-neg-frac87.3%

        \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\left(-\frac{0.5}{x}\right)} + x\right)} \]
      12. distribute-rgt-neg-in87.3%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(-\varepsilon \cdot \frac{0.5}{x}\right)} + x\right)} \]
      13. *-commutative87.3%

        \[\leadsto \frac{\varepsilon}{x + \left(\left(-\color{blue}{\frac{0.5}{x} \cdot \varepsilon}\right) + x\right)} \]
      14. distribute-lft-neg-in87.3%

        \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(-\frac{0.5}{x}\right) \cdot \varepsilon} + x\right)} \]
      15. fma-define87.3%

        \[\leadsto \frac{\varepsilon}{x + \color{blue}{\mathsf{fma}\left(-\frac{0.5}{x}, \varepsilon, x\right)}} \]
      16. distribute-neg-frac87.3%

        \[\leadsto \frac{\varepsilon}{x + \mathsf{fma}\left(\color{blue}{\frac{-0.5}{x}}, \varepsilon, x\right)} \]
      17. metadata-eval87.3%

        \[\leadsto \frac{\varepsilon}{x + \mathsf{fma}\left(\frac{\color{blue}{-0.5}}{x}, \varepsilon, x\right)} \]
    9. Simplified87.3%

      \[\leadsto \frac{\varepsilon}{x + \color{blue}{\mathsf{fma}\left(\frac{-0.5}{x}, \varepsilon, x\right)}} \]
    10. Taylor expanded in eps around 0 87.3%

      \[\leadsto \frac{\varepsilon}{\color{blue}{-0.5 \cdot \frac{\varepsilon}{x} + 2 \cdot x}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification90.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 9 \cdot 10^{-121}:\\ \;\;\;\;x - \sqrt{-\varepsilon}\\ \mathbf{elif}\;x \leq 4.8 \cdot 10^{-89}:\\ \;\;\;\;\frac{\varepsilon}{x + \left(x + \frac{\varepsilon}{x \cdot -2}\right)}\\ \mathbf{elif}\;x \leq 2.05 \cdot 10^{-81}:\\ \;\;\;\;x - \sqrt{-\varepsilon}\\ \mathbf{else}:\\ \;\;\;\;\frac{\varepsilon}{-0.5 \cdot \frac{\varepsilon}{x} + x \cdot 2}\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 44.6% accurate, 9.7× speedup?

\[\begin{array}{l} \\ \frac{\varepsilon}{-0.5 \cdot \frac{\varepsilon}{x} + x \cdot 2} \end{array} \]
(FPCore (x eps) :precision binary64 (/ eps (+ (* -0.5 (/ eps x)) (* x 2.0))))
double code(double x, double eps) {
	return eps / ((-0.5 * (eps / x)) + (x * 2.0));
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = eps / (((-0.5d0) * (eps / x)) + (x * 2.0d0))
end function
public static double code(double x, double eps) {
	return eps / ((-0.5 * (eps / x)) + (x * 2.0));
}
def code(x, eps):
	return eps / ((-0.5 * (eps / x)) + (x * 2.0))
function code(x, eps)
	return Float64(eps / Float64(Float64(-0.5 * Float64(eps / x)) + Float64(x * 2.0)))
end
function tmp = code(x, eps)
	tmp = eps / ((-0.5 * (eps / x)) + (x * 2.0));
end
code[x_, eps_] := N[(eps / N[(N[(-0.5 * N[(eps / x), $MachinePrecision]), $MachinePrecision] + N[(x * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\varepsilon}{-0.5 \cdot \frac{\varepsilon}{x} + x \cdot 2}
\end{array}
Derivation
  1. Initial program 63.3%

    \[x - \sqrt{x \cdot x - \varepsilon} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. flip--63.2%

      \[\leadsto \color{blue}{\frac{x \cdot x - \sqrt{x \cdot x - \varepsilon} \cdot \sqrt{x \cdot x - \varepsilon}}{x + \sqrt{x \cdot x - \varepsilon}}} \]
    2. div-inv63.0%

      \[\leadsto \color{blue}{\left(x \cdot x - \sqrt{x \cdot x - \varepsilon} \cdot \sqrt{x \cdot x - \varepsilon}\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}}} \]
    3. add-sqr-sqrt62.8%

      \[\leadsto \left(x \cdot x - \color{blue}{\left(x \cdot x - \varepsilon\right)}\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
    4. associate--r-99.3%

      \[\leadsto \color{blue}{\left(\left(x \cdot x - x \cdot x\right) + \varepsilon\right)} \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
    5. pow299.3%

      \[\leadsto \left(\left(\color{blue}{{x}^{2}} - x \cdot x\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
    6. pow299.3%

      \[\leadsto \left(\left({x}^{2} - \color{blue}{{x}^{2}}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
    7. sub-neg99.3%

      \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{\color{blue}{x \cdot x + \left(-\varepsilon\right)}}} \]
    8. add-sqr-sqrt79.9%

      \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x + \color{blue}{\sqrt{-\varepsilon} \cdot \sqrt{-\varepsilon}}}} \]
    9. hypot-define79.9%

      \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \color{blue}{\mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
  4. Applied egg-rr79.9%

    \[\leadsto \color{blue}{\left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
  5. Step-by-step derivation
    1. *-commutative79.9%

      \[\leadsto \color{blue}{\frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right)} \]
    2. +-inverses79.9%

      \[\leadsto \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \left(\color{blue}{0} + \varepsilon\right) \]
    3. +-lft-identity79.9%

      \[\leadsto \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \color{blue}{\varepsilon} \]
    4. associate-*l/80.0%

      \[\leadsto \color{blue}{\frac{1 \cdot \varepsilon}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
    5. *-lft-identity80.0%

      \[\leadsto \frac{\color{blue}{\varepsilon}}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \]
  6. Simplified80.0%

    \[\leadsto \color{blue}{\frac{\varepsilon}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
  7. Taylor expanded in eps around 0 0.0%

    \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(x + 0.5 \cdot \frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x}\right)}} \]
  8. Step-by-step derivation
    1. +-commutative0.0%

      \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(0.5 \cdot \frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x} + x\right)}} \]
    2. *-commutative0.0%

      \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x} \cdot 0.5} + x\right)} \]
    3. associate-/l*0.0%

      \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(\varepsilon \cdot \frac{{\left(\sqrt{-1}\right)}^{2}}{x}\right)} \cdot 0.5 + x\right)} \]
    4. associate-*r*0.0%

      \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\varepsilon \cdot \left(\frac{{\left(\sqrt{-1}\right)}^{2}}{x} \cdot 0.5\right)} + x\right)} \]
    5. *-commutative0.0%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\left(0.5 \cdot \frac{{\left(\sqrt{-1}\right)}^{2}}{x}\right)} + x\right)} \]
    6. associate-*r/0.0%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\frac{0.5 \cdot {\left(\sqrt{-1}\right)}^{2}}{x}} + x\right)} \]
    7. unpow20.0%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{0.5 \cdot \color{blue}{\left(\sqrt{-1} \cdot \sqrt{-1}\right)}}{x} + x\right)} \]
    8. rem-square-sqrt43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{0.5 \cdot \color{blue}{-1}}{x} + x\right)} \]
    9. metadata-eval43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{\color{blue}{-0.5}}{x} + x\right)} \]
    10. metadata-eval43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{\color{blue}{-0.5}}{x} + x\right)} \]
    11. distribute-neg-frac43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\left(-\frac{0.5}{x}\right)} + x\right)} \]
    12. distribute-rgt-neg-in43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(-\varepsilon \cdot \frac{0.5}{x}\right)} + x\right)} \]
    13. *-commutative43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\left(-\color{blue}{\frac{0.5}{x} \cdot \varepsilon}\right) + x\right)} \]
    14. distribute-lft-neg-in43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(-\frac{0.5}{x}\right) \cdot \varepsilon} + x\right)} \]
    15. fma-define43.3%

      \[\leadsto \frac{\varepsilon}{x + \color{blue}{\mathsf{fma}\left(-\frac{0.5}{x}, \varepsilon, x\right)}} \]
    16. distribute-neg-frac43.3%

      \[\leadsto \frac{\varepsilon}{x + \mathsf{fma}\left(\color{blue}{\frac{-0.5}{x}}, \varepsilon, x\right)} \]
    17. metadata-eval43.3%

      \[\leadsto \frac{\varepsilon}{x + \mathsf{fma}\left(\frac{\color{blue}{-0.5}}{x}, \varepsilon, x\right)} \]
  9. Simplified43.3%

    \[\leadsto \frac{\varepsilon}{x + \color{blue}{\mathsf{fma}\left(\frac{-0.5}{x}, \varepsilon, x\right)}} \]
  10. Taylor expanded in eps around 0 43.3%

    \[\leadsto \frac{\varepsilon}{\color{blue}{-0.5 \cdot \frac{\varepsilon}{x} + 2 \cdot x}} \]
  11. Final simplification43.3%

    \[\leadsto \frac{\varepsilon}{-0.5 \cdot \frac{\varepsilon}{x} + x \cdot 2} \]
  12. Add Preprocessing

Alternative 6: 44.6% accurate, 9.7× speedup?

\[\begin{array}{l} \\ \frac{\varepsilon}{x + \left(x + \frac{\varepsilon}{x \cdot -2}\right)} \end{array} \]
(FPCore (x eps) :precision binary64 (/ eps (+ x (+ x (/ eps (* x -2.0))))))
double code(double x, double eps) {
	return eps / (x + (x + (eps / (x * -2.0))));
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = eps / (x + (x + (eps / (x * (-2.0d0)))))
end function
public static double code(double x, double eps) {
	return eps / (x + (x + (eps / (x * -2.0))));
}
def code(x, eps):
	return eps / (x + (x + (eps / (x * -2.0))))
function code(x, eps)
	return Float64(eps / Float64(x + Float64(x + Float64(eps / Float64(x * -2.0)))))
end
function tmp = code(x, eps)
	tmp = eps / (x + (x + (eps / (x * -2.0))));
end
code[x_, eps_] := N[(eps / N[(x + N[(x + N[(eps / N[(x * -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\varepsilon}{x + \left(x + \frac{\varepsilon}{x \cdot -2}\right)}
\end{array}
Derivation
  1. Initial program 63.3%

    \[x - \sqrt{x \cdot x - \varepsilon} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. flip--63.2%

      \[\leadsto \color{blue}{\frac{x \cdot x - \sqrt{x \cdot x - \varepsilon} \cdot \sqrt{x \cdot x - \varepsilon}}{x + \sqrt{x \cdot x - \varepsilon}}} \]
    2. div-inv63.0%

      \[\leadsto \color{blue}{\left(x \cdot x - \sqrt{x \cdot x - \varepsilon} \cdot \sqrt{x \cdot x - \varepsilon}\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}}} \]
    3. add-sqr-sqrt62.8%

      \[\leadsto \left(x \cdot x - \color{blue}{\left(x \cdot x - \varepsilon\right)}\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
    4. associate--r-99.3%

      \[\leadsto \color{blue}{\left(\left(x \cdot x - x \cdot x\right) + \varepsilon\right)} \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
    5. pow299.3%

      \[\leadsto \left(\left(\color{blue}{{x}^{2}} - x \cdot x\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
    6. pow299.3%

      \[\leadsto \left(\left({x}^{2} - \color{blue}{{x}^{2}}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
    7. sub-neg99.3%

      \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{\color{blue}{x \cdot x + \left(-\varepsilon\right)}}} \]
    8. add-sqr-sqrt79.9%

      \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x + \color{blue}{\sqrt{-\varepsilon} \cdot \sqrt{-\varepsilon}}}} \]
    9. hypot-define79.9%

      \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \color{blue}{\mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
  4. Applied egg-rr79.9%

    \[\leadsto \color{blue}{\left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
  5. Step-by-step derivation
    1. *-commutative79.9%

      \[\leadsto \color{blue}{\frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right)} \]
    2. +-inverses79.9%

      \[\leadsto \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \left(\color{blue}{0} + \varepsilon\right) \]
    3. +-lft-identity79.9%

      \[\leadsto \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \color{blue}{\varepsilon} \]
    4. associate-*l/80.0%

      \[\leadsto \color{blue}{\frac{1 \cdot \varepsilon}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
    5. *-lft-identity80.0%

      \[\leadsto \frac{\color{blue}{\varepsilon}}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \]
  6. Simplified80.0%

    \[\leadsto \color{blue}{\frac{\varepsilon}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
  7. Taylor expanded in eps around 0 0.0%

    \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(x + 0.5 \cdot \frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x}\right)}} \]
  8. Step-by-step derivation
    1. +-commutative0.0%

      \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(0.5 \cdot \frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x} + x\right)}} \]
    2. *-commutative0.0%

      \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x} \cdot 0.5} + x\right)} \]
    3. associate-/l*0.0%

      \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(\varepsilon \cdot \frac{{\left(\sqrt{-1}\right)}^{2}}{x}\right)} \cdot 0.5 + x\right)} \]
    4. associate-*r*0.0%

      \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\varepsilon \cdot \left(\frac{{\left(\sqrt{-1}\right)}^{2}}{x} \cdot 0.5\right)} + x\right)} \]
    5. *-commutative0.0%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\left(0.5 \cdot \frac{{\left(\sqrt{-1}\right)}^{2}}{x}\right)} + x\right)} \]
    6. associate-*r/0.0%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\frac{0.5 \cdot {\left(\sqrt{-1}\right)}^{2}}{x}} + x\right)} \]
    7. unpow20.0%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{0.5 \cdot \color{blue}{\left(\sqrt{-1} \cdot \sqrt{-1}\right)}}{x} + x\right)} \]
    8. rem-square-sqrt43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{0.5 \cdot \color{blue}{-1}}{x} + x\right)} \]
    9. metadata-eval43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{\color{blue}{-0.5}}{x} + x\right)} \]
    10. metadata-eval43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{\color{blue}{-0.5}}{x} + x\right)} \]
    11. distribute-neg-frac43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\left(-\frac{0.5}{x}\right)} + x\right)} \]
    12. distribute-rgt-neg-in43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(-\varepsilon \cdot \frac{0.5}{x}\right)} + x\right)} \]
    13. *-commutative43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\left(-\color{blue}{\frac{0.5}{x} \cdot \varepsilon}\right) + x\right)} \]
    14. distribute-lft-neg-in43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(-\frac{0.5}{x}\right) \cdot \varepsilon} + x\right)} \]
    15. fma-define43.3%

      \[\leadsto \frac{\varepsilon}{x + \color{blue}{\mathsf{fma}\left(-\frac{0.5}{x}, \varepsilon, x\right)}} \]
    16. distribute-neg-frac43.3%

      \[\leadsto \frac{\varepsilon}{x + \mathsf{fma}\left(\color{blue}{\frac{-0.5}{x}}, \varepsilon, x\right)} \]
    17. metadata-eval43.3%

      \[\leadsto \frac{\varepsilon}{x + \mathsf{fma}\left(\frac{\color{blue}{-0.5}}{x}, \varepsilon, x\right)} \]
  9. Simplified43.3%

    \[\leadsto \frac{\varepsilon}{x + \color{blue}{\mathsf{fma}\left(\frac{-0.5}{x}, \varepsilon, x\right)}} \]
  10. Step-by-step derivation
    1. fma-undefine43.3%

      \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(\frac{-0.5}{x} \cdot \varepsilon + x\right)}} \]
    2. clear-num43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\frac{1}{\frac{x}{-0.5}}} \cdot \varepsilon + x\right)} \]
    3. associate-*l/43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\frac{1 \cdot \varepsilon}{\frac{x}{-0.5}}} + x\right)} \]
    4. *-un-lft-identity43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\frac{\color{blue}{\varepsilon}}{\frac{x}{-0.5}} + x\right)} \]
    5. div-inv43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\frac{\varepsilon}{\color{blue}{x \cdot \frac{1}{-0.5}}} + x\right)} \]
    6. metadata-eval43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\frac{\varepsilon}{x \cdot \color{blue}{-2}} + x\right)} \]
  11. Applied egg-rr43.3%

    \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(\frac{\varepsilon}{x \cdot -2} + x\right)}} \]
  12. Final simplification43.3%

    \[\leadsto \frac{\varepsilon}{x + \left(x + \frac{\varepsilon}{x \cdot -2}\right)} \]
  13. Add Preprocessing

Alternative 7: 43.7% accurate, 21.4× speedup?

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

\\
\frac{\varepsilon}{x} \cdot 0.5
\end{array}
Derivation
  1. Initial program 63.3%

    \[x - \sqrt{x \cdot x - \varepsilon} \]
  2. Add Preprocessing
  3. Taylor expanded in x around inf 42.8%

    \[\leadsto \color{blue}{0.5 \cdot \frac{\varepsilon}{x}} \]
  4. Final simplification42.8%

    \[\leadsto \frac{\varepsilon}{x} \cdot 0.5 \]
  5. Add Preprocessing

Alternative 8: 5.4% accurate, 35.7× speedup?

\[\begin{array}{l} \\ x \cdot -2 \end{array} \]
(FPCore (x eps) :precision binary64 (* x -2.0))
double code(double x, double eps) {
	return x * -2.0;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = x * (-2.0d0)
end function
public static double code(double x, double eps) {
	return x * -2.0;
}
def code(x, eps):
	return x * -2.0
function code(x, eps)
	return Float64(x * -2.0)
end
function tmp = code(x, eps)
	tmp = x * -2.0;
end
code[x_, eps_] := N[(x * -2.0), $MachinePrecision]
\begin{array}{l}

\\
x \cdot -2
\end{array}
Derivation
  1. Initial program 63.3%

    \[x - \sqrt{x \cdot x - \varepsilon} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. flip--63.2%

      \[\leadsto \color{blue}{\frac{x \cdot x - \sqrt{x \cdot x - \varepsilon} \cdot \sqrt{x \cdot x - \varepsilon}}{x + \sqrt{x \cdot x - \varepsilon}}} \]
    2. div-inv63.0%

      \[\leadsto \color{blue}{\left(x \cdot x - \sqrt{x \cdot x - \varepsilon} \cdot \sqrt{x \cdot x - \varepsilon}\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}}} \]
    3. add-sqr-sqrt62.8%

      \[\leadsto \left(x \cdot x - \color{blue}{\left(x \cdot x - \varepsilon\right)}\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
    4. associate--r-99.3%

      \[\leadsto \color{blue}{\left(\left(x \cdot x - x \cdot x\right) + \varepsilon\right)} \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
    5. pow299.3%

      \[\leadsto \left(\left(\color{blue}{{x}^{2}} - x \cdot x\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
    6. pow299.3%

      \[\leadsto \left(\left({x}^{2} - \color{blue}{{x}^{2}}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x - \varepsilon}} \]
    7. sub-neg99.3%

      \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{\color{blue}{x \cdot x + \left(-\varepsilon\right)}}} \]
    8. add-sqr-sqrt79.9%

      \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \sqrt{x \cdot x + \color{blue}{\sqrt{-\varepsilon} \cdot \sqrt{-\varepsilon}}}} \]
    9. hypot-define79.9%

      \[\leadsto \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \color{blue}{\mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
  4. Applied egg-rr79.9%

    \[\leadsto \color{blue}{\left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right) \cdot \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
  5. Step-by-step derivation
    1. *-commutative79.9%

      \[\leadsto \color{blue}{\frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \left(\left({x}^{2} - {x}^{2}\right) + \varepsilon\right)} \]
    2. +-inverses79.9%

      \[\leadsto \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \left(\color{blue}{0} + \varepsilon\right) \]
    3. +-lft-identity79.9%

      \[\leadsto \frac{1}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \cdot \color{blue}{\varepsilon} \]
    4. associate-*l/80.0%

      \[\leadsto \color{blue}{\frac{1 \cdot \varepsilon}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
    5. *-lft-identity80.0%

      \[\leadsto \frac{\color{blue}{\varepsilon}}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)} \]
  6. Simplified80.0%

    \[\leadsto \color{blue}{\frac{\varepsilon}{x + \mathsf{hypot}\left(x, \sqrt{-\varepsilon}\right)}} \]
  7. Taylor expanded in eps around 0 0.0%

    \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(x + 0.5 \cdot \frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x}\right)}} \]
  8. Step-by-step derivation
    1. +-commutative0.0%

      \[\leadsto \frac{\varepsilon}{x + \color{blue}{\left(0.5 \cdot \frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x} + x\right)}} \]
    2. *-commutative0.0%

      \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\frac{\varepsilon \cdot {\left(\sqrt{-1}\right)}^{2}}{x} \cdot 0.5} + x\right)} \]
    3. associate-/l*0.0%

      \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(\varepsilon \cdot \frac{{\left(\sqrt{-1}\right)}^{2}}{x}\right)} \cdot 0.5 + x\right)} \]
    4. associate-*r*0.0%

      \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\varepsilon \cdot \left(\frac{{\left(\sqrt{-1}\right)}^{2}}{x} \cdot 0.5\right)} + x\right)} \]
    5. *-commutative0.0%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\left(0.5 \cdot \frac{{\left(\sqrt{-1}\right)}^{2}}{x}\right)} + x\right)} \]
    6. associate-*r/0.0%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\frac{0.5 \cdot {\left(\sqrt{-1}\right)}^{2}}{x}} + x\right)} \]
    7. unpow20.0%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{0.5 \cdot \color{blue}{\left(\sqrt{-1} \cdot \sqrt{-1}\right)}}{x} + x\right)} \]
    8. rem-square-sqrt43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{0.5 \cdot \color{blue}{-1}}{x} + x\right)} \]
    9. metadata-eval43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{\color{blue}{-0.5}}{x} + x\right)} \]
    10. metadata-eval43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \frac{\color{blue}{-0.5}}{x} + x\right)} \]
    11. distribute-neg-frac43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\varepsilon \cdot \color{blue}{\left(-\frac{0.5}{x}\right)} + x\right)} \]
    12. distribute-rgt-neg-in43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(-\varepsilon \cdot \frac{0.5}{x}\right)} + x\right)} \]
    13. *-commutative43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\left(-\color{blue}{\frac{0.5}{x} \cdot \varepsilon}\right) + x\right)} \]
    14. distribute-lft-neg-in43.3%

      \[\leadsto \frac{\varepsilon}{x + \left(\color{blue}{\left(-\frac{0.5}{x}\right) \cdot \varepsilon} + x\right)} \]
    15. fma-define43.3%

      \[\leadsto \frac{\varepsilon}{x + \color{blue}{\mathsf{fma}\left(-\frac{0.5}{x}, \varepsilon, x\right)}} \]
    16. distribute-neg-frac43.3%

      \[\leadsto \frac{\varepsilon}{x + \mathsf{fma}\left(\color{blue}{\frac{-0.5}{x}}, \varepsilon, x\right)} \]
    17. metadata-eval43.3%

      \[\leadsto \frac{\varepsilon}{x + \mathsf{fma}\left(\frac{\color{blue}{-0.5}}{x}, \varepsilon, x\right)} \]
  9. Simplified43.3%

    \[\leadsto \frac{\varepsilon}{x + \color{blue}{\mathsf{fma}\left(\frac{-0.5}{x}, \varepsilon, x\right)}} \]
  10. Taylor expanded in eps around inf 5.4%

    \[\leadsto \color{blue}{-2 \cdot x} \]
  11. Step-by-step derivation
    1. *-commutative5.4%

      \[\leadsto \color{blue}{x \cdot -2} \]
  12. Simplified5.4%

    \[\leadsto \color{blue}{x \cdot -2} \]
  13. Add Preprocessing

Developer target: 99.5% accurate, 1.0× speedup?

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

\\
\frac{\varepsilon}{x + \sqrt{x \cdot x - \varepsilon}}
\end{array}

Reproduce

?
herbie shell --seed 2024103 
(FPCore (x eps)
  :name "ENA, Section 1.4, Exercise 4d"
  :precision binary64
  :pre (and (and (<= 0.0 x) (<= x 1000000000.0)) (and (<= -1.0 eps) (<= eps 1.0)))

  :alt
  (/ eps (+ x (sqrt (- (* x x) eps))))

  (- x (sqrt (- (* x x) eps))))