Hyperbolic arcsine

Percentage Accurate: 17.6% → 99.5%
Time: 9.6s
Alternatives: 7
Speedup: 207.0×

Specification

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

\\
\log \left(x + \sqrt{x \cdot x + 1}\right)
\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: 17.6% accurate, 1.0× speedup?

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

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

Alternative 1: 99.5% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -0.9:\\ \;\;\;\;0 - \log \left(x \cdot -2 + \frac{-0.5 + \frac{0.125}{x \cdot x}}{x}\right)\\ \mathbf{elif}\;x \leq 0.96:\\ \;\;\;\;x + \left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2 + \frac{0.5}{x}\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -0.9)
   (- 0.0 (log (+ (* x -2.0) (/ (+ -0.5 (/ 0.125 (* x x))) x))))
   (if (<= x 0.96)
     (+ x (* (* x (* x x)) -0.16666666666666666))
     (log (+ (* x 2.0) (/ 0.5 x))))))
double code(double x) {
	double tmp;
	if (x <= -0.9) {
		tmp = 0.0 - log(((x * -2.0) + ((-0.5 + (0.125 / (x * x))) / x)));
	} else if (x <= 0.96) {
		tmp = x + ((x * (x * x)) * -0.16666666666666666);
	} else {
		tmp = log(((x * 2.0) + (0.5 / x)));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-0.9d0)) then
        tmp = 0.0d0 - log(((x * (-2.0d0)) + (((-0.5d0) + (0.125d0 / (x * x))) / x)))
    else if (x <= 0.96d0) then
        tmp = x + ((x * (x * x)) * (-0.16666666666666666d0))
    else
        tmp = log(((x * 2.0d0) + (0.5d0 / x)))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -0.9) {
		tmp = 0.0 - Math.log(((x * -2.0) + ((-0.5 + (0.125 / (x * x))) / x)));
	} else if (x <= 0.96) {
		tmp = x + ((x * (x * x)) * -0.16666666666666666);
	} else {
		tmp = Math.log(((x * 2.0) + (0.5 / x)));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -0.9:
		tmp = 0.0 - math.log(((x * -2.0) + ((-0.5 + (0.125 / (x * x))) / x)))
	elif x <= 0.96:
		tmp = x + ((x * (x * x)) * -0.16666666666666666)
	else:
		tmp = math.log(((x * 2.0) + (0.5 / x)))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -0.9)
		tmp = Float64(0.0 - log(Float64(Float64(x * -2.0) + Float64(Float64(-0.5 + Float64(0.125 / Float64(x * x))) / x))));
	elseif (x <= 0.96)
		tmp = Float64(x + Float64(Float64(x * Float64(x * x)) * -0.16666666666666666));
	else
		tmp = log(Float64(Float64(x * 2.0) + Float64(0.5 / x)));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -0.9)
		tmp = 0.0 - log(((x * -2.0) + ((-0.5 + (0.125 / (x * x))) / x)));
	elseif (x <= 0.96)
		tmp = x + ((x * (x * x)) * -0.16666666666666666);
	else
		tmp = log(((x * 2.0) + (0.5 / x)));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -0.9], N[(0.0 - N[Log[N[(N[(x * -2.0), $MachinePrecision] + N[(N[(-0.5 + N[(0.125 / N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 0.96], N[(x + N[(N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] * -0.16666666666666666), $MachinePrecision]), $MachinePrecision], N[Log[N[(N[(x * 2.0), $MachinePrecision] + N[(0.5 / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -0.9:\\
\;\;\;\;0 - \log \left(x \cdot -2 + \frac{-0.5 + \frac{0.125}{x \cdot x}}{x}\right)\\

\mathbf{elif}\;x \leq 0.96:\\
\;\;\;\;x + \left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666\\

\mathbf{else}:\\
\;\;\;\;\log \left(x \cdot 2 + \frac{0.5}{x}\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -0.900000000000000022

    1. Initial program 3.9%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around -inf

      \[\leadsto \mathsf{log.f64}\left(\color{blue}{\left(-1 \cdot \frac{\left(\frac{1}{2} + \frac{\frac{1}{16}}{{x}^{4}}\right) - \frac{1}{8} \cdot \frac{1}{{x}^{2}}}{x}\right)}\right) \]
    4. Step-by-step derivation
      1. associate-*r/N/A

        \[\leadsto \mathsf{log.f64}\left(\left(\frac{-1 \cdot \left(\left(\frac{1}{2} + \frac{\frac{1}{16}}{{x}^{4}}\right) - \frac{1}{8} \cdot \frac{1}{{x}^{2}}\right)}{x}\right)\right) \]
      2. /-lowering-/.f64N/A

        \[\leadsto \mathsf{log.f64}\left(\mathsf{/.f64}\left(\left(-1 \cdot \left(\left(\frac{1}{2} + \frac{\frac{1}{16}}{{x}^{4}}\right) - \frac{1}{8} \cdot \frac{1}{{x}^{2}}\right)\right), x\right)\right) \]
    5. Simplified99.3%

      \[\leadsto \log \color{blue}{\left(\frac{\frac{0.125}{x \cdot x} + \left(-0.5 + \frac{-0.0625}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)}{x}\right)} \]
    6. Step-by-step derivation
      1. clear-numN/A

        \[\leadsto \log \left(\frac{1}{\frac{x}{\frac{\frac{1}{8}}{x \cdot x} + \left(\frac{-1}{2} + \frac{\frac{-1}{16}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)}}\right) \]
      2. log-recN/A

        \[\leadsto \mathsf{neg}\left(\log \left(\frac{x}{\frac{\frac{1}{8}}{x \cdot x} + \left(\frac{-1}{2} + \frac{\frac{-1}{16}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)}\right)\right) \]
      3. neg-lowering-neg.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\log \left(\frac{x}{\frac{\frac{1}{8}}{x \cdot x} + \left(\frac{-1}{2} + \frac{\frac{-1}{16}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)}\right)\right) \]
      4. log-lowering-log.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\left(\frac{x}{\frac{\frac{1}{8}}{x \cdot x} + \left(\frac{-1}{2} + \frac{\frac{-1}{16}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)}\right)\right)\right) \]
      5. /-lowering-/.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \left(\frac{\frac{1}{8}}{x \cdot x} + \left(\frac{-1}{2} + \frac{\frac{-1}{16}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)\right)\right)\right)\right) \]
      6. associate-+r+N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \left(\left(\frac{\frac{1}{8}}{x \cdot x} + \frac{-1}{2}\right) + \frac{\frac{-1}{16}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)\right)\right)\right) \]
      7. +-commutativeN/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \left(\frac{\frac{-1}{16}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)} + \left(\frac{\frac{1}{8}}{x \cdot x} + \frac{-1}{2}\right)\right)\right)\right)\right) \]
      8. +-lowering-+.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\left(\frac{\frac{-1}{16}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right), \left(\frac{\frac{1}{8}}{x \cdot x} + \frac{-1}{2}\right)\right)\right)\right)\right) \]
      9. /-lowering-/.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{16}, \left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right)\right), \left(\frac{\frac{1}{8}}{x \cdot x} + \frac{-1}{2}\right)\right)\right)\right)\right) \]
      10. *-lowering-*.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{16}, \mathsf{*.f64}\left(x, \left(x \cdot \left(x \cdot x\right)\right)\right)\right), \left(\frac{\frac{1}{8}}{x \cdot x} + \frac{-1}{2}\right)\right)\right)\right)\right) \]
      11. *-lowering-*.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{16}, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \left(x \cdot x\right)\right)\right)\right), \left(\frac{\frac{1}{8}}{x \cdot x} + \frac{-1}{2}\right)\right)\right)\right)\right) \]
      12. *-lowering-*.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{16}, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \left(\frac{\frac{1}{8}}{x \cdot x} + \frac{-1}{2}\right)\right)\right)\right)\right) \]
      13. +-lowering-+.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{16}, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{+.f64}\left(\left(\frac{\frac{1}{8}}{x \cdot x}\right), \frac{-1}{2}\right)\right)\right)\right)\right) \]
    7. Applied egg-rr99.4%

      \[\leadsto \color{blue}{-\log \left(\frac{x}{\frac{-0.0625}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)} + \left(\frac{\frac{0.125}{x}}{x} + -0.5\right)}\right)} \]
    8. Taylor expanded in x around inf

      \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\color{blue}{\left(x \cdot \left(\frac{\frac{1}{8}}{{x}^{4}} - \left(2 + \frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)\right)}\right)\right) \]
    9. Simplified99.4%

      \[\leadsto -\log \color{blue}{\left(x \cdot -2 + \frac{-0.5 + \frac{0.125}{x \cdot x}}{x}\right)} \]

    if -0.900000000000000022 < x < 0.95999999999999996

    1. Initial program 8.1%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

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

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

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \color{blue}{\left(\frac{-1}{6} \cdot {x}^{2}\right)}\right)\right) \]
      3. *-commutativeN/A

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \left({x}^{2} \cdot \color{blue}{\frac{-1}{6}}\right)\right)\right) \]
      4. unpow2N/A

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \left(\left(x \cdot x\right) \cdot \frac{-1}{6}\right)\right)\right) \]
      5. associate-*l*N/A

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

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \color{blue}{\left(x \cdot \frac{-1}{6}\right)}\right)\right)\right) \]
      7. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{\frac{-1}{6}}\right)\right)\right)\right) \]
    5. Simplified100.0%

      \[\leadsto \color{blue}{x \cdot \left(1 + x \cdot \left(x \cdot -0.16666666666666666\right)\right)} \]
    6. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto x \cdot \left(x \cdot \left(x \cdot \frac{-1}{6}\right) + \color{blue}{1}\right) \]
      2. distribute-rgt-inN/A

        \[\leadsto \left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right) \cdot x + \color{blue}{1 \cdot x} \]
      3. *-lft-identityN/A

        \[\leadsto \left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right) \cdot x + x \]
      4. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\left(\left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right) \cdot x\right), \color{blue}{x}\right) \]
      5. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\left(x \cdot \left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right)\right), x\right) \]
      6. associate-*r*N/A

        \[\leadsto \mathsf{+.f64}\left(\left(x \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{6}\right)\right), x\right) \]
      7. associate-*r*N/A

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

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

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \left(x \cdot x\right)\right), \frac{-1}{6}\right), x\right) \]
      10. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right), \frac{-1}{6}\right), x\right) \]
    7. Applied egg-rr100.0%

      \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666 + x} \]

    if 0.95999999999999996 < x

    1. Initial program 53.1%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \mathsf{log.f64}\left(\color{blue}{\left(x \cdot \left(2 + \frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)}\right) \]
    4. Step-by-step derivation
      1. distribute-rgt-inN/A

        \[\leadsto \mathsf{log.f64}\left(\left(2 \cdot x + \left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right) \cdot x\right)\right) \]
      2. +-lowering-+.f64N/A

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

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

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \left(\left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right) \cdot x\right)\right)\right) \]
      5. associate-*r/N/A

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

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

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \left(\frac{\frac{1}{2} \cdot x}{{x}^{2}}\right)\right)\right) \]
      8. unpow2N/A

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \left(\frac{\frac{1}{2} \cdot x}{x \cdot x}\right)\right)\right) \]
      9. associate-/r*N/A

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \left(\frac{\frac{\frac{1}{2} \cdot x}{x}}{x}\right)\right)\right) \]
      10. associate-/l*N/A

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \left(\frac{\frac{1}{2} \cdot \frac{x}{x}}{x}\right)\right)\right) \]
      11. *-inversesN/A

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

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \left(\frac{\frac{1}{2}}{x}\right)\right)\right) \]
      13. /-lowering-/.f64100.0%

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \mathsf{/.f64}\left(\frac{1}{2}, x\right)\right)\right) \]
    5. Simplified100.0%

      \[\leadsto \log \color{blue}{\left(x \cdot 2 + \frac{0.5}{x}\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -0.9:\\ \;\;\;\;0 - \log \left(x \cdot -2 + \frac{-0.5 + \frac{0.125}{x \cdot x}}{x}\right)\\ \mathbf{elif}\;x \leq 0.96:\\ \;\;\;\;x + \left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2 + \frac{0.5}{x}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 99.5% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -0.95:\\ \;\;\;\;0 - \log \left(x \cdot -2 + \frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 0.96:\\ \;\;\;\;x + \left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2 + \frac{0.5}{x}\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -0.95)
   (- 0.0 (log (+ (* x -2.0) (/ -0.5 x))))
   (if (<= x 0.96)
     (+ x (* (* x (* x x)) -0.16666666666666666))
     (log (+ (* x 2.0) (/ 0.5 x))))))
double code(double x) {
	double tmp;
	if (x <= -0.95) {
		tmp = 0.0 - log(((x * -2.0) + (-0.5 / x)));
	} else if (x <= 0.96) {
		tmp = x + ((x * (x * x)) * -0.16666666666666666);
	} else {
		tmp = log(((x * 2.0) + (0.5 / x)));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-0.95d0)) then
        tmp = 0.0d0 - log(((x * (-2.0d0)) + ((-0.5d0) / x)))
    else if (x <= 0.96d0) then
        tmp = x + ((x * (x * x)) * (-0.16666666666666666d0))
    else
        tmp = log(((x * 2.0d0) + (0.5d0 / x)))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -0.95) {
		tmp = 0.0 - Math.log(((x * -2.0) + (-0.5 / x)));
	} else if (x <= 0.96) {
		tmp = x + ((x * (x * x)) * -0.16666666666666666);
	} else {
		tmp = Math.log(((x * 2.0) + (0.5 / x)));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -0.95:
		tmp = 0.0 - math.log(((x * -2.0) + (-0.5 / x)))
	elif x <= 0.96:
		tmp = x + ((x * (x * x)) * -0.16666666666666666)
	else:
		tmp = math.log(((x * 2.0) + (0.5 / x)))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -0.95)
		tmp = Float64(0.0 - log(Float64(Float64(x * -2.0) + Float64(-0.5 / x))));
	elseif (x <= 0.96)
		tmp = Float64(x + Float64(Float64(x * Float64(x * x)) * -0.16666666666666666));
	else
		tmp = log(Float64(Float64(x * 2.0) + Float64(0.5 / x)));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -0.95)
		tmp = 0.0 - log(((x * -2.0) + (-0.5 / x)));
	elseif (x <= 0.96)
		tmp = x + ((x * (x * x)) * -0.16666666666666666);
	else
		tmp = log(((x * 2.0) + (0.5 / x)));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -0.95], N[(0.0 - N[Log[N[(N[(x * -2.0), $MachinePrecision] + N[(-0.5 / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 0.96], N[(x + N[(N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] * -0.16666666666666666), $MachinePrecision]), $MachinePrecision], N[Log[N[(N[(x * 2.0), $MachinePrecision] + N[(0.5 / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -0.95:\\
\;\;\;\;0 - \log \left(x \cdot -2 + \frac{-0.5}{x}\right)\\

\mathbf{elif}\;x \leq 0.96:\\
\;\;\;\;x + \left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666\\

\mathbf{else}:\\
\;\;\;\;\log \left(x \cdot 2 + \frac{0.5}{x}\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -0.94999999999999996

    1. Initial program 3.9%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around -inf

      \[\leadsto \mathsf{log.f64}\left(\color{blue}{\left(-1 \cdot \frac{\left(\frac{1}{2} + \frac{\frac{1}{16}}{{x}^{4}}\right) - \frac{1}{8} \cdot \frac{1}{{x}^{2}}}{x}\right)}\right) \]
    4. Step-by-step derivation
      1. associate-*r/N/A

        \[\leadsto \mathsf{log.f64}\left(\left(\frac{-1 \cdot \left(\left(\frac{1}{2} + \frac{\frac{1}{16}}{{x}^{4}}\right) - \frac{1}{8} \cdot \frac{1}{{x}^{2}}\right)}{x}\right)\right) \]
      2. /-lowering-/.f64N/A

        \[\leadsto \mathsf{log.f64}\left(\mathsf{/.f64}\left(\left(-1 \cdot \left(\left(\frac{1}{2} + \frac{\frac{1}{16}}{{x}^{4}}\right) - \frac{1}{8} \cdot \frac{1}{{x}^{2}}\right)\right), x\right)\right) \]
    5. Simplified99.3%

      \[\leadsto \log \color{blue}{\left(\frac{\frac{0.125}{x \cdot x} + \left(-0.5 + \frac{-0.0625}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)}{x}\right)} \]
    6. Step-by-step derivation
      1. clear-numN/A

        \[\leadsto \log \left(\frac{1}{\frac{x}{\frac{\frac{1}{8}}{x \cdot x} + \left(\frac{-1}{2} + \frac{\frac{-1}{16}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)}}\right) \]
      2. log-recN/A

        \[\leadsto \mathsf{neg}\left(\log \left(\frac{x}{\frac{\frac{1}{8}}{x \cdot x} + \left(\frac{-1}{2} + \frac{\frac{-1}{16}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)}\right)\right) \]
      3. neg-lowering-neg.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\log \left(\frac{x}{\frac{\frac{1}{8}}{x \cdot x} + \left(\frac{-1}{2} + \frac{\frac{-1}{16}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)}\right)\right) \]
      4. log-lowering-log.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\left(\frac{x}{\frac{\frac{1}{8}}{x \cdot x} + \left(\frac{-1}{2} + \frac{\frac{-1}{16}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)}\right)\right)\right) \]
      5. /-lowering-/.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \left(\frac{\frac{1}{8}}{x \cdot x} + \left(\frac{-1}{2} + \frac{\frac{-1}{16}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)\right)\right)\right)\right) \]
      6. associate-+r+N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \left(\left(\frac{\frac{1}{8}}{x \cdot x} + \frac{-1}{2}\right) + \frac{\frac{-1}{16}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)\right)\right)\right) \]
      7. +-commutativeN/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \left(\frac{\frac{-1}{16}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)} + \left(\frac{\frac{1}{8}}{x \cdot x} + \frac{-1}{2}\right)\right)\right)\right)\right) \]
      8. +-lowering-+.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\left(\frac{\frac{-1}{16}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right), \left(\frac{\frac{1}{8}}{x \cdot x} + \frac{-1}{2}\right)\right)\right)\right)\right) \]
      9. /-lowering-/.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{16}, \left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right)\right), \left(\frac{\frac{1}{8}}{x \cdot x} + \frac{-1}{2}\right)\right)\right)\right)\right) \]
      10. *-lowering-*.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{16}, \mathsf{*.f64}\left(x, \left(x \cdot \left(x \cdot x\right)\right)\right)\right), \left(\frac{\frac{1}{8}}{x \cdot x} + \frac{-1}{2}\right)\right)\right)\right)\right) \]
      11. *-lowering-*.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{16}, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \left(x \cdot x\right)\right)\right)\right), \left(\frac{\frac{1}{8}}{x \cdot x} + \frac{-1}{2}\right)\right)\right)\right)\right) \]
      12. *-lowering-*.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{16}, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \left(\frac{\frac{1}{8}}{x \cdot x} + \frac{-1}{2}\right)\right)\right)\right)\right) \]
      13. +-lowering-+.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{16}, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{+.f64}\left(\left(\frac{\frac{1}{8}}{x \cdot x}\right), \frac{-1}{2}\right)\right)\right)\right)\right) \]
    7. Applied egg-rr99.4%

      \[\leadsto \color{blue}{-\log \left(\frac{x}{\frac{-0.0625}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)} + \left(\frac{\frac{0.125}{x}}{x} + -0.5\right)}\right)} \]
    8. Taylor expanded in x around inf

      \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\color{blue}{\left(-1 \cdot \left(x \cdot \left(2 + \frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)\right)}\right)\right) \]
    9. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\left(\mathsf{neg}\left(x \cdot \left(2 + \frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)\right)\right)\right) \]
      2. distribute-lft-inN/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\left(\mathsf{neg}\left(\left(x \cdot 2 + x \cdot \left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)\right)\right)\right)\right) \]
      3. distribute-neg-inN/A

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

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\left(\left(\mathsf{neg}\left(x \cdot 2\right)\right) + \left(\mathsf{neg}\left(\left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right) \cdot x\right)\right)\right)\right)\right) \]
      5. +-lowering-+.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{+.f64}\left(\left(\mathsf{neg}\left(x \cdot 2\right)\right), \left(\mathsf{neg}\left(\left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right) \cdot x\right)\right)\right)\right)\right) \]
      6. distribute-rgt-neg-inN/A

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

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

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

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, -2\right), \left(\mathsf{neg}\left(x \cdot \left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)\right)\right)\right)\right) \]
      10. associate-*r/N/A

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

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, -2\right), \left(\mathsf{neg}\left(x \cdot \frac{\frac{1}{2}}{{x}^{2}}\right)\right)\right)\right)\right) \]
      12. associate-*r/N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, -2\right), \left(\mathsf{neg}\left(\frac{x \cdot \frac{1}{2}}{{x}^{2}}\right)\right)\right)\right)\right) \]
      13. unpow2N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, -2\right), \left(\mathsf{neg}\left(\frac{x \cdot \frac{1}{2}}{x \cdot x}\right)\right)\right)\right)\right) \]
      14. associate-/r*N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, -2\right), \left(\mathsf{neg}\left(\frac{\frac{x \cdot \frac{1}{2}}{x}}{x}\right)\right)\right)\right)\right) \]
      15. distribute-neg-fracN/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, -2\right), \left(\frac{\mathsf{neg}\left(\frac{x \cdot \frac{1}{2}}{x}\right)}{x}\right)\right)\right)\right) \]
      16. *-rgt-identityN/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, -2\right), \left(\frac{\mathsf{neg}\left(\frac{x \cdot \frac{1}{2}}{x \cdot 1}\right)}{x}\right)\right)\right)\right) \]
      17. times-fracN/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, -2\right), \left(\frac{\mathsf{neg}\left(\frac{x}{x} \cdot \frac{\frac{1}{2}}{1}\right)}{x}\right)\right)\right)\right) \]
      18. *-inversesN/A

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

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

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, -2\right), \left(\frac{\mathsf{neg}\left(\frac{1}{2}\right)}{x}\right)\right)\right)\right) \]
    10. Simplified99.2%

      \[\leadsto -\log \color{blue}{\left(x \cdot -2 + \frac{-0.5}{x}\right)} \]

    if -0.94999999999999996 < x < 0.95999999999999996

    1. Initial program 8.1%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

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

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

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \color{blue}{\left(\frac{-1}{6} \cdot {x}^{2}\right)}\right)\right) \]
      3. *-commutativeN/A

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \left({x}^{2} \cdot \color{blue}{\frac{-1}{6}}\right)\right)\right) \]
      4. unpow2N/A

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \left(\left(x \cdot x\right) \cdot \frac{-1}{6}\right)\right)\right) \]
      5. associate-*l*N/A

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

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \color{blue}{\left(x \cdot \frac{-1}{6}\right)}\right)\right)\right) \]
      7. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{\frac{-1}{6}}\right)\right)\right)\right) \]
    5. Simplified100.0%

      \[\leadsto \color{blue}{x \cdot \left(1 + x \cdot \left(x \cdot -0.16666666666666666\right)\right)} \]
    6. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto x \cdot \left(x \cdot \left(x \cdot \frac{-1}{6}\right) + \color{blue}{1}\right) \]
      2. distribute-rgt-inN/A

        \[\leadsto \left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right) \cdot x + \color{blue}{1 \cdot x} \]
      3. *-lft-identityN/A

        \[\leadsto \left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right) \cdot x + x \]
      4. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\left(\left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right) \cdot x\right), \color{blue}{x}\right) \]
      5. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\left(x \cdot \left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right)\right), x\right) \]
      6. associate-*r*N/A

        \[\leadsto \mathsf{+.f64}\left(\left(x \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{6}\right)\right), x\right) \]
      7. associate-*r*N/A

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

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

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \left(x \cdot x\right)\right), \frac{-1}{6}\right), x\right) \]
      10. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right), \frac{-1}{6}\right), x\right) \]
    7. Applied egg-rr100.0%

      \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666 + x} \]

    if 0.95999999999999996 < x

    1. Initial program 53.1%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \mathsf{log.f64}\left(\color{blue}{\left(x \cdot \left(2 + \frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)}\right) \]
    4. Step-by-step derivation
      1. distribute-rgt-inN/A

        \[\leadsto \mathsf{log.f64}\left(\left(2 \cdot x + \left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right) \cdot x\right)\right) \]
      2. +-lowering-+.f64N/A

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

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

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \left(\left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right) \cdot x\right)\right)\right) \]
      5. associate-*r/N/A

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

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

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \left(\frac{\frac{1}{2} \cdot x}{{x}^{2}}\right)\right)\right) \]
      8. unpow2N/A

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \left(\frac{\frac{1}{2} \cdot x}{x \cdot x}\right)\right)\right) \]
      9. associate-/r*N/A

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \left(\frac{\frac{\frac{1}{2} \cdot x}{x}}{x}\right)\right)\right) \]
      10. associate-/l*N/A

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \left(\frac{\frac{1}{2} \cdot \frac{x}{x}}{x}\right)\right)\right) \]
      11. *-inversesN/A

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

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \left(\frac{\frac{1}{2}}{x}\right)\right)\right) \]
      13. /-lowering-/.f64100.0%

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \mathsf{/.f64}\left(\frac{1}{2}, x\right)\right)\right) \]
    5. Simplified100.0%

      \[\leadsto \log \color{blue}{\left(x \cdot 2 + \frac{0.5}{x}\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -0.95:\\ \;\;\;\;0 - \log \left(x \cdot -2 + \frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 0.96:\\ \;\;\;\;x + \left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2 + \frac{0.5}{x}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 99.4% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.3:\\ \;\;\;\;0 - \log \left(\frac{x}{-0.5}\right)\\ \mathbf{elif}\;x \leq 0.96:\\ \;\;\;\;x + \left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2 + \frac{0.5}{x}\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.3)
   (- 0.0 (log (/ x -0.5)))
   (if (<= x 0.96)
     (+ x (* (* x (* x x)) -0.16666666666666666))
     (log (+ (* x 2.0) (/ 0.5 x))))))
double code(double x) {
	double tmp;
	if (x <= -1.3) {
		tmp = 0.0 - log((x / -0.5));
	} else if (x <= 0.96) {
		tmp = x + ((x * (x * x)) * -0.16666666666666666);
	} else {
		tmp = log(((x * 2.0) + (0.5 / x)));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1.3d0)) then
        tmp = 0.0d0 - log((x / (-0.5d0)))
    else if (x <= 0.96d0) then
        tmp = x + ((x * (x * x)) * (-0.16666666666666666d0))
    else
        tmp = log(((x * 2.0d0) + (0.5d0 / x)))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -1.3) {
		tmp = 0.0 - Math.log((x / -0.5));
	} else if (x <= 0.96) {
		tmp = x + ((x * (x * x)) * -0.16666666666666666);
	} else {
		tmp = Math.log(((x * 2.0) + (0.5 / x)));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -1.3:
		tmp = 0.0 - math.log((x / -0.5))
	elif x <= 0.96:
		tmp = x + ((x * (x * x)) * -0.16666666666666666)
	else:
		tmp = math.log(((x * 2.0) + (0.5 / x)))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -1.3)
		tmp = Float64(0.0 - log(Float64(x / -0.5)));
	elseif (x <= 0.96)
		tmp = Float64(x + Float64(Float64(x * Float64(x * x)) * -0.16666666666666666));
	else
		tmp = log(Float64(Float64(x * 2.0) + Float64(0.5 / x)));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1.3)
		tmp = 0.0 - log((x / -0.5));
	elseif (x <= 0.96)
		tmp = x + ((x * (x * x)) * -0.16666666666666666);
	else
		tmp = log(((x * 2.0) + (0.5 / x)));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -1.3], N[(0.0 - N[Log[N[(x / -0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 0.96], N[(x + N[(N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] * -0.16666666666666666), $MachinePrecision]), $MachinePrecision], N[Log[N[(N[(x * 2.0), $MachinePrecision] + N[(0.5 / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.3:\\
\;\;\;\;0 - \log \left(\frac{x}{-0.5}\right)\\

\mathbf{elif}\;x \leq 0.96:\\
\;\;\;\;x + \left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666\\

\mathbf{else}:\\
\;\;\;\;\log \left(x \cdot 2 + \frac{0.5}{x}\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -1.30000000000000004

    1. Initial program 3.9%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around -inf

      \[\leadsto \mathsf{log.f64}\left(\color{blue}{\left(\frac{\frac{-1}{2}}{x}\right)}\right) \]
    4. Step-by-step derivation
      1. /-lowering-/.f6499.0%

        \[\leadsto \mathsf{log.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right)\right) \]
    5. Simplified99.0%

      \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
    6. Step-by-step derivation
      1. clear-numN/A

        \[\leadsto \log \left(\frac{1}{\frac{x}{\frac{-1}{2}}}\right) \]
      2. log-recN/A

        \[\leadsto \mathsf{neg}\left(\log \left(\frac{x}{\frac{-1}{2}}\right)\right) \]
      3. neg-lowering-neg.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\log \left(\frac{x}{\frac{-1}{2}}\right)\right) \]
      4. log-lowering-log.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\left(\frac{x}{\frac{-1}{2}}\right)\right)\right) \]
      5. /-lowering-/.f6499.0%

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \frac{-1}{2}\right)\right)\right) \]
    7. Applied egg-rr99.0%

      \[\leadsto \color{blue}{-\log \left(\frac{x}{-0.5}\right)} \]

    if -1.30000000000000004 < x < 0.95999999999999996

    1. Initial program 8.1%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

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

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

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \color{blue}{\left(\frac{-1}{6} \cdot {x}^{2}\right)}\right)\right) \]
      3. *-commutativeN/A

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \left({x}^{2} \cdot \color{blue}{\frac{-1}{6}}\right)\right)\right) \]
      4. unpow2N/A

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \left(\left(x \cdot x\right) \cdot \frac{-1}{6}\right)\right)\right) \]
      5. associate-*l*N/A

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

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \color{blue}{\left(x \cdot \frac{-1}{6}\right)}\right)\right)\right) \]
      7. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{\frac{-1}{6}}\right)\right)\right)\right) \]
    5. Simplified100.0%

      \[\leadsto \color{blue}{x \cdot \left(1 + x \cdot \left(x \cdot -0.16666666666666666\right)\right)} \]
    6. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto x \cdot \left(x \cdot \left(x \cdot \frac{-1}{6}\right) + \color{blue}{1}\right) \]
      2. distribute-rgt-inN/A

        \[\leadsto \left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right) \cdot x + \color{blue}{1 \cdot x} \]
      3. *-lft-identityN/A

        \[\leadsto \left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right) \cdot x + x \]
      4. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\left(\left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right) \cdot x\right), \color{blue}{x}\right) \]
      5. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\left(x \cdot \left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right)\right), x\right) \]
      6. associate-*r*N/A

        \[\leadsto \mathsf{+.f64}\left(\left(x \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{6}\right)\right), x\right) \]
      7. associate-*r*N/A

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

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

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \left(x \cdot x\right)\right), \frac{-1}{6}\right), x\right) \]
      10. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right), \frac{-1}{6}\right), x\right) \]
    7. Applied egg-rr100.0%

      \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666 + x} \]

    if 0.95999999999999996 < x

    1. Initial program 53.1%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \mathsf{log.f64}\left(\color{blue}{\left(x \cdot \left(2 + \frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)}\right) \]
    4. Step-by-step derivation
      1. distribute-rgt-inN/A

        \[\leadsto \mathsf{log.f64}\left(\left(2 \cdot x + \left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right) \cdot x\right)\right) \]
      2. +-lowering-+.f64N/A

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

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

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \left(\left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right) \cdot x\right)\right)\right) \]
      5. associate-*r/N/A

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

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

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \left(\frac{\frac{1}{2} \cdot x}{{x}^{2}}\right)\right)\right) \]
      8. unpow2N/A

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \left(\frac{\frac{1}{2} \cdot x}{x \cdot x}\right)\right)\right) \]
      9. associate-/r*N/A

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \left(\frac{\frac{\frac{1}{2} \cdot x}{x}}{x}\right)\right)\right) \]
      10. associate-/l*N/A

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \left(\frac{\frac{1}{2} \cdot \frac{x}{x}}{x}\right)\right)\right) \]
      11. *-inversesN/A

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

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \left(\frac{\frac{1}{2}}{x}\right)\right)\right) \]
      13. /-lowering-/.f64100.0%

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(x, 2\right), \mathsf{/.f64}\left(\frac{1}{2}, x\right)\right)\right) \]
    5. Simplified100.0%

      \[\leadsto \log \color{blue}{\left(x \cdot 2 + \frac{0.5}{x}\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.3:\\ \;\;\;\;0 - \log \left(\frac{x}{-0.5}\right)\\ \mathbf{elif}\;x \leq 0.96:\\ \;\;\;\;x + \left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2 + \frac{0.5}{x}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 99.2% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.3:\\ \;\;\;\;0 - \log \left(\frac{x}{-0.5}\right)\\ \mathbf{elif}\;x \leq 1.25:\\ \;\;\;\;x + \left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.3)
   (- 0.0 (log (/ x -0.5)))
   (if (<= x 1.25)
     (+ x (* (* x (* x x)) -0.16666666666666666))
     (log (+ x x)))))
double code(double x) {
	double tmp;
	if (x <= -1.3) {
		tmp = 0.0 - log((x / -0.5));
	} else if (x <= 1.25) {
		tmp = x + ((x * (x * x)) * -0.16666666666666666);
	} else {
		tmp = log((x + x));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1.3d0)) then
        tmp = 0.0d0 - log((x / (-0.5d0)))
    else if (x <= 1.25d0) then
        tmp = x + ((x * (x * x)) * (-0.16666666666666666d0))
    else
        tmp = log((x + x))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -1.3) {
		tmp = 0.0 - Math.log((x / -0.5));
	} else if (x <= 1.25) {
		tmp = x + ((x * (x * x)) * -0.16666666666666666);
	} else {
		tmp = Math.log((x + x));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -1.3:
		tmp = 0.0 - math.log((x / -0.5))
	elif x <= 1.25:
		tmp = x + ((x * (x * x)) * -0.16666666666666666)
	else:
		tmp = math.log((x + x))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -1.3)
		tmp = Float64(0.0 - log(Float64(x / -0.5)));
	elseif (x <= 1.25)
		tmp = Float64(x + Float64(Float64(x * Float64(x * x)) * -0.16666666666666666));
	else
		tmp = log(Float64(x + x));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1.3)
		tmp = 0.0 - log((x / -0.5));
	elseif (x <= 1.25)
		tmp = x + ((x * (x * x)) * -0.16666666666666666);
	else
		tmp = log((x + x));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -1.3], N[(0.0 - N[Log[N[(x / -0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 1.25], N[(x + N[(N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] * -0.16666666666666666), $MachinePrecision]), $MachinePrecision], N[Log[N[(x + x), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.3:\\
\;\;\;\;0 - \log \left(\frac{x}{-0.5}\right)\\

\mathbf{elif}\;x \leq 1.25:\\
\;\;\;\;x + \left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666\\

\mathbf{else}:\\
\;\;\;\;\log \left(x + x\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -1.30000000000000004

    1. Initial program 3.9%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around -inf

      \[\leadsto \mathsf{log.f64}\left(\color{blue}{\left(\frac{\frac{-1}{2}}{x}\right)}\right) \]
    4. Step-by-step derivation
      1. /-lowering-/.f6499.0%

        \[\leadsto \mathsf{log.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right)\right) \]
    5. Simplified99.0%

      \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
    6. Step-by-step derivation
      1. clear-numN/A

        \[\leadsto \log \left(\frac{1}{\frac{x}{\frac{-1}{2}}}\right) \]
      2. log-recN/A

        \[\leadsto \mathsf{neg}\left(\log \left(\frac{x}{\frac{-1}{2}}\right)\right) \]
      3. neg-lowering-neg.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\log \left(\frac{x}{\frac{-1}{2}}\right)\right) \]
      4. log-lowering-log.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\left(\frac{x}{\frac{-1}{2}}\right)\right)\right) \]
      5. /-lowering-/.f6499.0%

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \frac{-1}{2}\right)\right)\right) \]
    7. Applied egg-rr99.0%

      \[\leadsto \color{blue}{-\log \left(\frac{x}{-0.5}\right)} \]

    if -1.30000000000000004 < x < 1.25

    1. Initial program 8.1%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

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

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

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \color{blue}{\left(\frac{-1}{6} \cdot {x}^{2}\right)}\right)\right) \]
      3. *-commutativeN/A

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \left({x}^{2} \cdot \color{blue}{\frac{-1}{6}}\right)\right)\right) \]
      4. unpow2N/A

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \left(\left(x \cdot x\right) \cdot \frac{-1}{6}\right)\right)\right) \]
      5. associate-*l*N/A

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

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \color{blue}{\left(x \cdot \frac{-1}{6}\right)}\right)\right)\right) \]
      7. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{\frac{-1}{6}}\right)\right)\right)\right) \]
    5. Simplified100.0%

      \[\leadsto \color{blue}{x \cdot \left(1 + x \cdot \left(x \cdot -0.16666666666666666\right)\right)} \]
    6. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto x \cdot \left(x \cdot \left(x \cdot \frac{-1}{6}\right) + \color{blue}{1}\right) \]
      2. distribute-rgt-inN/A

        \[\leadsto \left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right) \cdot x + \color{blue}{1 \cdot x} \]
      3. *-lft-identityN/A

        \[\leadsto \left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right) \cdot x + x \]
      4. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\left(\left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right) \cdot x\right), \color{blue}{x}\right) \]
      5. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\left(x \cdot \left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right)\right), x\right) \]
      6. associate-*r*N/A

        \[\leadsto \mathsf{+.f64}\left(\left(x \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{6}\right)\right), x\right) \]
      7. associate-*r*N/A

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

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

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \left(x \cdot x\right)\right), \frac{-1}{6}\right), x\right) \]
      10. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right), \frac{-1}{6}\right), x\right) \]
    7. Applied egg-rr100.0%

      \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666 + x} \]

    if 1.25 < x

    1. Initial program 53.1%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \color{blue}{x}\right)\right) \]
    4. Step-by-step derivation
      1. Simplified99.7%

        \[\leadsto \log \left(x + \color{blue}{x}\right) \]
    5. Recombined 3 regimes into one program.
    6. Final simplification99.7%

      \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.3:\\ \;\;\;\;0 - \log \left(\frac{x}{-0.5}\right)\\ \mathbf{elif}\;x \leq 1.25:\\ \;\;\;\;x + \left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \]
    7. Add Preprocessing

    Alternative 5: 99.3% accurate, 1.8× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.3:\\ \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.25:\\ \;\;\;\;x + \left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= x -1.3)
       (log (/ -0.5 x))
       (if (<= x 1.25)
         (+ x (* (* x (* x x)) -0.16666666666666666))
         (log (+ x x)))))
    double code(double x) {
    	double tmp;
    	if (x <= -1.3) {
    		tmp = log((-0.5 / x));
    	} else if (x <= 1.25) {
    		tmp = x + ((x * (x * x)) * -0.16666666666666666);
    	} else {
    		tmp = log((x + x));
    	}
    	return tmp;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        real(8) :: tmp
        if (x <= (-1.3d0)) then
            tmp = log(((-0.5d0) / x))
        else if (x <= 1.25d0) then
            tmp = x + ((x * (x * x)) * (-0.16666666666666666d0))
        else
            tmp = log((x + x))
        end if
        code = tmp
    end function
    
    public static double code(double x) {
    	double tmp;
    	if (x <= -1.3) {
    		tmp = Math.log((-0.5 / x));
    	} else if (x <= 1.25) {
    		tmp = x + ((x * (x * x)) * -0.16666666666666666);
    	} else {
    		tmp = Math.log((x + x));
    	}
    	return tmp;
    }
    
    def code(x):
    	tmp = 0
    	if x <= -1.3:
    		tmp = math.log((-0.5 / x))
    	elif x <= 1.25:
    		tmp = x + ((x * (x * x)) * -0.16666666666666666)
    	else:
    		tmp = math.log((x + x))
    	return tmp
    
    function code(x)
    	tmp = 0.0
    	if (x <= -1.3)
    		tmp = log(Float64(-0.5 / x));
    	elseif (x <= 1.25)
    		tmp = Float64(x + Float64(Float64(x * Float64(x * x)) * -0.16666666666666666));
    	else
    		tmp = log(Float64(x + x));
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	tmp = 0.0;
    	if (x <= -1.3)
    		tmp = log((-0.5 / x));
    	elseif (x <= 1.25)
    		tmp = x + ((x * (x * x)) * -0.16666666666666666);
    	else
    		tmp = log((x + x));
    	end
    	tmp_2 = tmp;
    end
    
    code[x_] := If[LessEqual[x, -1.3], N[Log[N[(-0.5 / x), $MachinePrecision]], $MachinePrecision], If[LessEqual[x, 1.25], N[(x + N[(N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] * -0.16666666666666666), $MachinePrecision]), $MachinePrecision], N[Log[N[(x + x), $MachinePrecision]], $MachinePrecision]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq -1.3:\\
    \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\
    
    \mathbf{elif}\;x \leq 1.25:\\
    \;\;\;\;x + \left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666\\
    
    \mathbf{else}:\\
    \;\;\;\;\log \left(x + x\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if x < -1.30000000000000004

      1. Initial program 3.9%

        \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
      2. Add Preprocessing
      3. Taylor expanded in x around -inf

        \[\leadsto \mathsf{log.f64}\left(\color{blue}{\left(\frac{\frac{-1}{2}}{x}\right)}\right) \]
      4. Step-by-step derivation
        1. /-lowering-/.f6499.0%

          \[\leadsto \mathsf{log.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right)\right) \]
      5. Simplified99.0%

        \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]

      if -1.30000000000000004 < x < 1.25

      1. Initial program 8.1%

        \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
      2. Add Preprocessing
      3. Taylor expanded in x around 0

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

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

          \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \color{blue}{\left(\frac{-1}{6} \cdot {x}^{2}\right)}\right)\right) \]
        3. *-commutativeN/A

          \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \left({x}^{2} \cdot \color{blue}{\frac{-1}{6}}\right)\right)\right) \]
        4. unpow2N/A

          \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \left(\left(x \cdot x\right) \cdot \frac{-1}{6}\right)\right)\right) \]
        5. associate-*l*N/A

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

          \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \color{blue}{\left(x \cdot \frac{-1}{6}\right)}\right)\right)\right) \]
        7. *-lowering-*.f64100.0%

          \[\leadsto \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{\frac{-1}{6}}\right)\right)\right)\right) \]
      5. Simplified100.0%

        \[\leadsto \color{blue}{x \cdot \left(1 + x \cdot \left(x \cdot -0.16666666666666666\right)\right)} \]
      6. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto x \cdot \left(x \cdot \left(x \cdot \frac{-1}{6}\right) + \color{blue}{1}\right) \]
        2. distribute-rgt-inN/A

          \[\leadsto \left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right) \cdot x + \color{blue}{1 \cdot x} \]
        3. *-lft-identityN/A

          \[\leadsto \left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right) \cdot x + x \]
        4. +-lowering-+.f64N/A

          \[\leadsto \mathsf{+.f64}\left(\left(\left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right) \cdot x\right), \color{blue}{x}\right) \]
        5. *-commutativeN/A

          \[\leadsto \mathsf{+.f64}\left(\left(x \cdot \left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right)\right), x\right) \]
        6. associate-*r*N/A

          \[\leadsto \mathsf{+.f64}\left(\left(x \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{6}\right)\right), x\right) \]
        7. associate-*r*N/A

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

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

          \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \left(x \cdot x\right)\right), \frac{-1}{6}\right), x\right) \]
        10. *-lowering-*.f64100.0%

          \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right), \frac{-1}{6}\right), x\right) \]
      7. Applied egg-rr100.0%

        \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666 + x} \]

      if 1.25 < x

      1. Initial program 53.1%

        \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
      2. Add Preprocessing
      3. Taylor expanded in x around inf

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \color{blue}{x}\right)\right) \]
      4. Step-by-step derivation
        1. Simplified99.7%

          \[\leadsto \log \left(x + \color{blue}{x}\right) \]
      5. Recombined 3 regimes into one program.
      6. Final simplification99.7%

        \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.3:\\ \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.25:\\ \;\;\;\;x + \left(x \cdot \left(x \cdot x\right)\right) \cdot -0.16666666666666666\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \]
      7. Add Preprocessing

      Alternative 6: 74.4% accurate, 1.9× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.25:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \end{array} \]
      (FPCore (x) :precision binary64 (if (<= x 1.25) x (log (+ x x))))
      double code(double x) {
      	double tmp;
      	if (x <= 1.25) {
      		tmp = x;
      	} else {
      		tmp = log((x + x));
      	}
      	return tmp;
      }
      
      real(8) function code(x)
          real(8), intent (in) :: x
          real(8) :: tmp
          if (x <= 1.25d0) then
              tmp = x
          else
              tmp = log((x + x))
          end if
          code = tmp
      end function
      
      public static double code(double x) {
      	double tmp;
      	if (x <= 1.25) {
      		tmp = x;
      	} else {
      		tmp = Math.log((x + x));
      	}
      	return tmp;
      }
      
      def code(x):
      	tmp = 0
      	if x <= 1.25:
      		tmp = x
      	else:
      		tmp = math.log((x + x))
      	return tmp
      
      function code(x)
      	tmp = 0.0
      	if (x <= 1.25)
      		tmp = x;
      	else
      		tmp = log(Float64(x + x));
      	end
      	return tmp
      end
      
      function tmp_2 = code(x)
      	tmp = 0.0;
      	if (x <= 1.25)
      		tmp = x;
      	else
      		tmp = log((x + x));
      	end
      	tmp_2 = tmp;
      end
      
      code[x_] := If[LessEqual[x, 1.25], x, N[Log[N[(x + x), $MachinePrecision]], $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;x \leq 1.25:\\
      \;\;\;\;x\\
      
      \mathbf{else}:\\
      \;\;\;\;\log \left(x + x\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if x < 1.25

        1. Initial program 6.6%

          \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
        2. Add Preprocessing
        3. Taylor expanded in x around 0

          \[\leadsto \color{blue}{x} \]
        4. Step-by-step derivation
          1. Simplified65.1%

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

          if 1.25 < x

          1. Initial program 53.1%

            \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
          2. Add Preprocessing
          3. Taylor expanded in x around inf

            \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \color{blue}{x}\right)\right) \]
          4. Step-by-step derivation
            1. Simplified99.7%

              \[\leadsto \log \left(x + \color{blue}{x}\right) \]
          5. Recombined 2 regimes into one program.
          6. Add Preprocessing

          Alternative 7: 51.9% accurate, 207.0× speedup?

          \[\begin{array}{l} \\ x \end{array} \]
          (FPCore (x) :precision binary64 x)
          double code(double x) {
          	return x;
          }
          
          real(8) function code(x)
              real(8), intent (in) :: x
              code = x
          end function
          
          public static double code(double x) {
          	return x;
          }
          
          def code(x):
          	return x
          
          function code(x)
          	return x
          end
          
          function tmp = code(x)
          	tmp = x;
          end
          
          code[x_] := x
          
          \begin{array}{l}
          
          \\
          x
          \end{array}
          
          Derivation
          1. Initial program 18.2%

            \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
          2. Add Preprocessing
          3. Taylor expanded in x around 0

            \[\leadsto \color{blue}{x} \]
          4. Step-by-step derivation
            1. Simplified50.2%

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

            Developer Target 1: 30.1% accurate, 1.0× speedup?

            \[\begin{array}{l} \\ \begin{array}{l} t_0 := \sqrt{x \cdot x + 1}\\ \mathbf{if}\;x < 0:\\ \;\;\;\;\log \left(\frac{-1}{x - t\_0}\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + t\_0\right)\\ \end{array} \end{array} \]
            (FPCore (x)
             :precision binary64
             (let* ((t_0 (sqrt (+ (* x x) 1.0))))
               (if (< x 0.0) (log (/ -1.0 (- x t_0))) (log (+ x t_0)))))
            double code(double x) {
            	double t_0 = sqrt(((x * x) + 1.0));
            	double tmp;
            	if (x < 0.0) {
            		tmp = log((-1.0 / (x - t_0)));
            	} else {
            		tmp = log((x + t_0));
            	}
            	return tmp;
            }
            
            real(8) function code(x)
                real(8), intent (in) :: x
                real(8) :: t_0
                real(8) :: tmp
                t_0 = sqrt(((x * x) + 1.0d0))
                if (x < 0.0d0) then
                    tmp = log(((-1.0d0) / (x - t_0)))
                else
                    tmp = log((x + t_0))
                end if
                code = tmp
            end function
            
            public static double code(double x) {
            	double t_0 = Math.sqrt(((x * x) + 1.0));
            	double tmp;
            	if (x < 0.0) {
            		tmp = Math.log((-1.0 / (x - t_0)));
            	} else {
            		tmp = Math.log((x + t_0));
            	}
            	return tmp;
            }
            
            def code(x):
            	t_0 = math.sqrt(((x * x) + 1.0))
            	tmp = 0
            	if x < 0.0:
            		tmp = math.log((-1.0 / (x - t_0)))
            	else:
            		tmp = math.log((x + t_0))
            	return tmp
            
            function code(x)
            	t_0 = sqrt(Float64(Float64(x * x) + 1.0))
            	tmp = 0.0
            	if (x < 0.0)
            		tmp = log(Float64(-1.0 / Float64(x - t_0)));
            	else
            		tmp = log(Float64(x + t_0));
            	end
            	return tmp
            end
            
            function tmp_2 = code(x)
            	t_0 = sqrt(((x * x) + 1.0));
            	tmp = 0.0;
            	if (x < 0.0)
            		tmp = log((-1.0 / (x - t_0)));
            	else
            		tmp = log((x + t_0));
            	end
            	tmp_2 = tmp;
            end
            
            code[x_] := Block[{t$95$0 = N[Sqrt[N[(N[(x * x), $MachinePrecision] + 1.0), $MachinePrecision]], $MachinePrecision]}, If[Less[x, 0.0], N[Log[N[(-1.0 / N[(x - t$95$0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], N[Log[N[(x + t$95$0), $MachinePrecision]], $MachinePrecision]]]
            
            \begin{array}{l}
            
            \\
            \begin{array}{l}
            t_0 := \sqrt{x \cdot x + 1}\\
            \mathbf{if}\;x < 0:\\
            \;\;\;\;\log \left(\frac{-1}{x - t\_0}\right)\\
            
            \mathbf{else}:\\
            \;\;\;\;\log \left(x + t\_0\right)\\
            
            
            \end{array}
            \end{array}
            

            Reproduce

            ?
            herbie shell --seed 2024192 
            (FPCore (x)
              :name "Hyperbolic arcsine"
              :precision binary64
            
              :alt
              (! :herbie-platform default (if (< x 0) (log (/ -1 (- x (sqrt (+ (* x x) 1))))) (log (+ x (sqrt (+ (* x x) 1))))))
            
              (log (+ x (sqrt (+ (* x x) 1.0)))))