Hyperbolic arcsine

Percentage Accurate: 19.0% → 99.6%
Time: 8.8s
Alternatives: 8
Speedup: 7.2×

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 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: 19.0% 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: 99.6% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.15:\\ \;\;\;\;\log \left(\frac{\frac{0.125}{x \cdot x} - 0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.05:\\ \;\;\;\;\mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + \left(x - \frac{-0.5}{x}\right)\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.15)
   (log (/ (- (/ 0.125 (* x x)) 0.5) x))
   (if (<= x 1.05)
     (fma (* (* x x) x) (fma 0.075 (* x x) -0.16666666666666666) x)
     (log (+ x (- x (/ -0.5 x)))))))
double code(double x) {
	double tmp;
	if (x <= -1.15) {
		tmp = log((((0.125 / (x * x)) - 0.5) / x));
	} else if (x <= 1.05) {
		tmp = fma(((x * x) * x), fma(0.075, (x * x), -0.16666666666666666), x);
	} else {
		tmp = log((x + (x - (-0.5 / x))));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= -1.15)
		tmp = log(Float64(Float64(Float64(0.125 / Float64(x * x)) - 0.5) / x));
	elseif (x <= 1.05)
		tmp = fma(Float64(Float64(x * x) * x), fma(0.075, Float64(x * x), -0.16666666666666666), x);
	else
		tmp = log(Float64(x + Float64(x - Float64(-0.5 / x))));
	end
	return tmp
end
code[x_] := If[LessEqual[x, -1.15], N[Log[N[(N[(N[(0.125 / N[(x * x), $MachinePrecision]), $MachinePrecision] - 0.5), $MachinePrecision] / x), $MachinePrecision]], $MachinePrecision], If[LessEqual[x, 1.05], N[(N[(N[(x * x), $MachinePrecision] * x), $MachinePrecision] * N[(0.075 * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] + x), $MachinePrecision], N[Log[N[(x + N[(x - N[(-0.5 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.15:\\
\;\;\;\;\log \left(\frac{\frac{0.125}{x \cdot x} - 0.5}{x}\right)\\

\mathbf{elif}\;x \leq 1.05:\\
\;\;\;\;\mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -1.1499999999999999

    1. Initial program 5.1%

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

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

        \[\leadsto \log \color{blue}{\left(\frac{-1 \cdot \left(\frac{1}{2} - \frac{1}{8} \cdot \frac{1}{{x}^{2}}\right)}{x}\right)} \]
      2. lower-/.f64N/A

        \[\leadsto \log \color{blue}{\left(\frac{-1 \cdot \left(\frac{1}{2} - \frac{1}{8} \cdot \frac{1}{{x}^{2}}\right)}{x}\right)} \]
      3. mul-1-negN/A

        \[\leadsto \log \left(\frac{\color{blue}{\mathsf{neg}\left(\left(\frac{1}{2} - \frac{1}{8} \cdot \frac{1}{{x}^{2}}\right)\right)}}{x}\right) \]
      4. neg-sub0N/A

        \[\leadsto \log \left(\frac{\color{blue}{0 - \left(\frac{1}{2} - \frac{1}{8} \cdot \frac{1}{{x}^{2}}\right)}}{x}\right) \]
      5. associate--r-N/A

        \[\leadsto \log \left(\frac{\color{blue}{\left(0 - \frac{1}{2}\right) + \frac{1}{8} \cdot \frac{1}{{x}^{2}}}}{x}\right) \]
      6. metadata-evalN/A

        \[\leadsto \log \left(\frac{\color{blue}{\frac{-1}{2}} + \frac{1}{8} \cdot \frac{1}{{x}^{2}}}{x}\right) \]
      7. +-commutativeN/A

        \[\leadsto \log \left(\frac{\color{blue}{\frac{1}{8} \cdot \frac{1}{{x}^{2}} + \frac{-1}{2}}}{x}\right) \]
      8. metadata-evalN/A

        \[\leadsto \log \left(\frac{\frac{1}{8} \cdot \frac{1}{{x}^{2}} + \color{blue}{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}}{x}\right) \]
      9. sub-negN/A

        \[\leadsto \log \left(\frac{\color{blue}{\frac{1}{8} \cdot \frac{1}{{x}^{2}} - \frac{1}{2}}}{x}\right) \]
      10. lower--.f64N/A

        \[\leadsto \log \left(\frac{\color{blue}{\frac{1}{8} \cdot \frac{1}{{x}^{2}} - \frac{1}{2}}}{x}\right) \]
      11. associate-*r/N/A

        \[\leadsto \log \left(\frac{\color{blue}{\frac{\frac{1}{8} \cdot 1}{{x}^{2}}} - \frac{1}{2}}{x}\right) \]
      12. metadata-evalN/A

        \[\leadsto \log \left(\frac{\frac{\color{blue}{\frac{1}{8}}}{{x}^{2}} - \frac{1}{2}}{x}\right) \]
      13. lower-/.f64N/A

        \[\leadsto \log \left(\frac{\color{blue}{\frac{\frac{1}{8}}{{x}^{2}}} - \frac{1}{2}}{x}\right) \]
      14. unpow2N/A

        \[\leadsto \log \left(\frac{\frac{\frac{1}{8}}{\color{blue}{x \cdot x}} - \frac{1}{2}}{x}\right) \]
      15. lower-*.f6499.6

        \[\leadsto \log \left(\frac{\frac{0.125}{\color{blue}{x \cdot x}} - 0.5}{x}\right) \]
    5. Applied rewrites99.6%

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

    if -1.1499999999999999 < x < 1.05000000000000004

    1. Initial program 10.5%

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

      \[\leadsto \color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right)} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto x \cdot \color{blue}{\left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + 1\right)} \]
      2. distribute-lft-inN/A

        \[\leadsto \color{blue}{x \cdot \left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right) + x \cdot 1} \]
      3. associate-*r*N/A

        \[\leadsto \color{blue}{\left(x \cdot {x}^{2}\right) \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)} + x \cdot 1 \]
      4. *-rgt-identityN/A

        \[\leadsto \left(x \cdot {x}^{2}\right) \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + \color{blue}{x} \]
      5. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot {x}^{2}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right)} \]
      6. *-commutativeN/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{2} \cdot x}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
      7. pow-plusN/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{\left(2 + 1\right)}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
      8. lower-pow.f64N/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{\left(2 + 1\right)}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
      9. metadata-evalN/A

        \[\leadsto \mathsf{fma}\left({x}^{\color{blue}{3}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
      10. sub-negN/A

        \[\leadsto \mathsf{fma}\left({x}^{3}, \color{blue}{\frac{3}{40} \cdot {x}^{2} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right)}, x\right) \]
      11. metadata-evalN/A

        \[\leadsto \mathsf{fma}\left({x}^{3}, \frac{3}{40} \cdot {x}^{2} + \color{blue}{\frac{-1}{6}}, x\right) \]
      12. lower-fma.f64N/A

        \[\leadsto \mathsf{fma}\left({x}^{3}, \color{blue}{\mathsf{fma}\left(\frac{3}{40}, {x}^{2}, \frac{-1}{6}\right)}, x\right) \]
      13. unpow2N/A

        \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(\frac{3}{40}, \color{blue}{x \cdot x}, \frac{-1}{6}\right), x\right) \]
      14. lower-*.f6499.5

        \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, \color{blue}{x \cdot x}, -0.16666666666666666\right), x\right) \]
    5. Applied rewrites99.5%

      \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)} \]
    6. Step-by-step derivation
      1. Applied rewrites99.5%

        \[\leadsto \mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(\color{blue}{0.075}, x \cdot x, -0.16666666666666666\right), x\right) \]

      if 1.05000000000000004 < x

      1. Initial program 48.3%

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

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

          \[\leadsto \log \left(x + \color{blue}{\left(x \cdot 1 + x \cdot \left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)}\right) \]
        2. *-rgt-identityN/A

          \[\leadsto \log \left(x + \left(\color{blue}{x} + x \cdot \left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)\right) \]
        3. cancel-sign-subN/A

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

          \[\leadsto \log \left(x + \left(x - \color{blue}{\left(-1 \cdot x\right)} \cdot \left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)\right) \]
        5. lower--.f64N/A

          \[\leadsto \log \left(x + \color{blue}{\left(x - \left(-1 \cdot x\right) \cdot \left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)}\right) \]
        6. mul-1-negN/A

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

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

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

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

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

          \[\leadsto \log \left(x + \left(x - \left(x \cdot \frac{1}{{x}^{2}}\right) \cdot \color{blue}{\frac{-1}{2}}\right)\right) \]
        12. unpow2N/A

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

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

          \[\leadsto \log \left(x + \left(x - \color{blue}{\frac{x \cdot \frac{1}{x}}{x}} \cdot \frac{-1}{2}\right)\right) \]
        15. rgt-mult-inverseN/A

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

          \[\leadsto \log \left(x + \left(x - \color{blue}{\frac{1 \cdot \frac{-1}{2}}{x}}\right)\right) \]
        17. metadata-evalN/A

          \[\leadsto \log \left(x + \left(x - \frac{\color{blue}{\frac{-1}{2}}}{x}\right)\right) \]
        18. lower-/.f6499.4

          \[\leadsto \log \left(x + \left(x - \color{blue}{\frac{-0.5}{x}}\right)\right) \]
      5. Applied rewrites99.4%

        \[\leadsto \log \left(x + \color{blue}{\left(x - \frac{-0.5}{x}\right)}\right) \]
    7. Recombined 3 regimes into one program.
    8. Add Preprocessing

    Alternative 2: 99.5% accurate, 0.9× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.3:\\ \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.05:\\ \;\;\;\;\mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + \left(x - \frac{-0.5}{x}\right)\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= x -1.3)
       (log (/ -0.5 x))
       (if (<= x 1.05)
         (fma (* (* x x) x) (fma 0.075 (* x x) -0.16666666666666666) x)
         (log (+ x (- x (/ -0.5 x)))))))
    double code(double x) {
    	double tmp;
    	if (x <= -1.3) {
    		tmp = log((-0.5 / x));
    	} else if (x <= 1.05) {
    		tmp = fma(((x * x) * x), fma(0.075, (x * x), -0.16666666666666666), x);
    	} else {
    		tmp = log((x + (x - (-0.5 / x))));
    	}
    	return tmp;
    }
    
    function code(x)
    	tmp = 0.0
    	if (x <= -1.3)
    		tmp = log(Float64(-0.5 / x));
    	elseif (x <= 1.05)
    		tmp = fma(Float64(Float64(x * x) * x), fma(0.075, Float64(x * x), -0.16666666666666666), x);
    	else
    		tmp = log(Float64(x + Float64(x - Float64(-0.5 / x))));
    	end
    	return tmp
    end
    
    code[x_] := If[LessEqual[x, -1.3], N[Log[N[(-0.5 / x), $MachinePrecision]], $MachinePrecision], If[LessEqual[x, 1.05], N[(N[(N[(x * x), $MachinePrecision] * x), $MachinePrecision] * N[(0.075 * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] + x), $MachinePrecision], N[Log[N[(x + N[(x - N[(-0.5 / x), $MachinePrecision]), $MachinePrecision]), $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 1.05:\\
    \;\;\;\;\mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\log \left(x + \left(x - \frac{-0.5}{x}\right)\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if x < -1.30000000000000004

      1. Initial program 5.1%

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

        \[\leadsto \log \color{blue}{\left(\frac{\frac{-1}{2}}{x}\right)} \]
      4. Step-by-step derivation
        1. lower-/.f6498.5

          \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
      5. Applied rewrites98.5%

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

      if -1.30000000000000004 < x < 1.05000000000000004

      1. Initial program 10.5%

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

        \[\leadsto \color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right)} \]
      4. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto x \cdot \color{blue}{\left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + 1\right)} \]
        2. distribute-lft-inN/A

          \[\leadsto \color{blue}{x \cdot \left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right) + x \cdot 1} \]
        3. associate-*r*N/A

          \[\leadsto \color{blue}{\left(x \cdot {x}^{2}\right) \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)} + x \cdot 1 \]
        4. *-rgt-identityN/A

          \[\leadsto \left(x \cdot {x}^{2}\right) \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + \color{blue}{x} \]
        5. lower-fma.f64N/A

          \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot {x}^{2}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right)} \]
        6. *-commutativeN/A

          \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{2} \cdot x}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
        7. pow-plusN/A

          \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{\left(2 + 1\right)}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
        8. lower-pow.f64N/A

          \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{\left(2 + 1\right)}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
        9. metadata-evalN/A

          \[\leadsto \mathsf{fma}\left({x}^{\color{blue}{3}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
        10. sub-negN/A

          \[\leadsto \mathsf{fma}\left({x}^{3}, \color{blue}{\frac{3}{40} \cdot {x}^{2} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right)}, x\right) \]
        11. metadata-evalN/A

          \[\leadsto \mathsf{fma}\left({x}^{3}, \frac{3}{40} \cdot {x}^{2} + \color{blue}{\frac{-1}{6}}, x\right) \]
        12. lower-fma.f64N/A

          \[\leadsto \mathsf{fma}\left({x}^{3}, \color{blue}{\mathsf{fma}\left(\frac{3}{40}, {x}^{2}, \frac{-1}{6}\right)}, x\right) \]
        13. unpow2N/A

          \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(\frac{3}{40}, \color{blue}{x \cdot x}, \frac{-1}{6}\right), x\right) \]
        14. lower-*.f6499.5

          \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, \color{blue}{x \cdot x}, -0.16666666666666666\right), x\right) \]
      5. Applied rewrites99.5%

        \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)} \]
      6. Step-by-step derivation
        1. Applied rewrites99.5%

          \[\leadsto \mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(\color{blue}{0.075}, x \cdot x, -0.16666666666666666\right), x\right) \]

        if 1.05000000000000004 < x

        1. Initial program 48.3%

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

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

            \[\leadsto \log \left(x + \color{blue}{\left(x \cdot 1 + x \cdot \left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)}\right) \]
          2. *-rgt-identityN/A

            \[\leadsto \log \left(x + \left(\color{blue}{x} + x \cdot \left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)\right) \]
          3. cancel-sign-subN/A

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

            \[\leadsto \log \left(x + \left(x - \color{blue}{\left(-1 \cdot x\right)} \cdot \left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)\right) \]
          5. lower--.f64N/A

            \[\leadsto \log \left(x + \color{blue}{\left(x - \left(-1 \cdot x\right) \cdot \left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)}\right) \]
          6. mul-1-negN/A

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

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

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

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

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

            \[\leadsto \log \left(x + \left(x - \left(x \cdot \frac{1}{{x}^{2}}\right) \cdot \color{blue}{\frac{-1}{2}}\right)\right) \]
          12. unpow2N/A

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

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

            \[\leadsto \log \left(x + \left(x - \color{blue}{\frac{x \cdot \frac{1}{x}}{x}} \cdot \frac{-1}{2}\right)\right) \]
          15. rgt-mult-inverseN/A

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

            \[\leadsto \log \left(x + \left(x - \color{blue}{\frac{1 \cdot \frac{-1}{2}}{x}}\right)\right) \]
          17. metadata-evalN/A

            \[\leadsto \log \left(x + \left(x - \frac{\color{blue}{\frac{-1}{2}}}{x}\right)\right) \]
          18. lower-/.f6499.4

            \[\leadsto \log \left(x + \left(x - \color{blue}{\frac{-0.5}{x}}\right)\right) \]
        5. Applied rewrites99.4%

          \[\leadsto \log \left(x + \color{blue}{\left(x - \frac{-0.5}{x}\right)}\right) \]
      7. Recombined 3 regimes into one program.
      8. Add Preprocessing

      Alternative 3: 99.4% accurate, 1.0× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.3:\\ \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.35:\\ \;\;\;\;\mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(2 \cdot x\right)\\ \end{array} \end{array} \]
      (FPCore (x)
       :precision binary64
       (if (<= x -1.3)
         (log (/ -0.5 x))
         (if (<= x 1.35)
           (fma (* (* x x) x) (fma 0.075 (* x x) -0.16666666666666666) x)
           (log (* 2.0 x)))))
      double code(double x) {
      	double tmp;
      	if (x <= -1.3) {
      		tmp = log((-0.5 / x));
      	} else if (x <= 1.35) {
      		tmp = fma(((x * x) * x), fma(0.075, (x * x), -0.16666666666666666), x);
      	} else {
      		tmp = log((2.0 * x));
      	}
      	return tmp;
      }
      
      function code(x)
      	tmp = 0.0
      	if (x <= -1.3)
      		tmp = log(Float64(-0.5 / x));
      	elseif (x <= 1.35)
      		tmp = fma(Float64(Float64(x * x) * x), fma(0.075, Float64(x * x), -0.16666666666666666), x);
      	else
      		tmp = log(Float64(2.0 * x));
      	end
      	return tmp
      end
      
      code[x_] := If[LessEqual[x, -1.3], N[Log[N[(-0.5 / x), $MachinePrecision]], $MachinePrecision], If[LessEqual[x, 1.35], N[(N[(N[(x * x), $MachinePrecision] * x), $MachinePrecision] * N[(0.075 * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] + x), $MachinePrecision], N[Log[N[(2.0 * 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 1.35:\\
      \;\;\;\;\mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\log \left(2 \cdot x\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 3 regimes
      2. if x < -1.30000000000000004

        1. Initial program 5.1%

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

          \[\leadsto \log \color{blue}{\left(\frac{\frac{-1}{2}}{x}\right)} \]
        4. Step-by-step derivation
          1. lower-/.f6498.5

            \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
        5. Applied rewrites98.5%

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

        if -1.30000000000000004 < x < 1.3500000000000001

        1. Initial program 10.5%

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

          \[\leadsto \color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right)} \]
        4. Step-by-step derivation
          1. +-commutativeN/A

            \[\leadsto x \cdot \color{blue}{\left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + 1\right)} \]
          2. distribute-lft-inN/A

            \[\leadsto \color{blue}{x \cdot \left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right) + x \cdot 1} \]
          3. associate-*r*N/A

            \[\leadsto \color{blue}{\left(x \cdot {x}^{2}\right) \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)} + x \cdot 1 \]
          4. *-rgt-identityN/A

            \[\leadsto \left(x \cdot {x}^{2}\right) \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + \color{blue}{x} \]
          5. lower-fma.f64N/A

            \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot {x}^{2}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right)} \]
          6. *-commutativeN/A

            \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{2} \cdot x}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
          7. pow-plusN/A

            \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{\left(2 + 1\right)}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
          8. lower-pow.f64N/A

            \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{\left(2 + 1\right)}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
          9. metadata-evalN/A

            \[\leadsto \mathsf{fma}\left({x}^{\color{blue}{3}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
          10. sub-negN/A

            \[\leadsto \mathsf{fma}\left({x}^{3}, \color{blue}{\frac{3}{40} \cdot {x}^{2} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right)}, x\right) \]
          11. metadata-evalN/A

            \[\leadsto \mathsf{fma}\left({x}^{3}, \frac{3}{40} \cdot {x}^{2} + \color{blue}{\frac{-1}{6}}, x\right) \]
          12. lower-fma.f64N/A

            \[\leadsto \mathsf{fma}\left({x}^{3}, \color{blue}{\mathsf{fma}\left(\frac{3}{40}, {x}^{2}, \frac{-1}{6}\right)}, x\right) \]
          13. unpow2N/A

            \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(\frac{3}{40}, \color{blue}{x \cdot x}, \frac{-1}{6}\right), x\right) \]
          14. lower-*.f6499.5

            \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, \color{blue}{x \cdot x}, -0.16666666666666666\right), x\right) \]
        5. Applied rewrites99.5%

          \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)} \]
        6. Step-by-step derivation
          1. Applied rewrites99.5%

            \[\leadsto \mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(\color{blue}{0.075}, x \cdot x, -0.16666666666666666\right), x\right) \]

          if 1.3500000000000001 < x

          1. Initial program 48.3%

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

            \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
          4. Step-by-step derivation
            1. lower-*.f6499.1

              \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
          5. Applied rewrites99.1%

            \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
        7. Recombined 3 regimes into one program.
        8. Add Preprocessing

        Alternative 4: 76.3% accurate, 1.1× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.35:\\ \;\;\;\;\mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(2 \cdot x\right)\\ \end{array} \end{array} \]
        (FPCore (x)
         :precision binary64
         (if (<= x 1.35)
           (fma (* (* x x) x) (fma 0.075 (* x x) -0.16666666666666666) x)
           (log (* 2.0 x))))
        double code(double x) {
        	double tmp;
        	if (x <= 1.35) {
        		tmp = fma(((x * x) * x), fma(0.075, (x * x), -0.16666666666666666), x);
        	} else {
        		tmp = log((2.0 * x));
        	}
        	return tmp;
        }
        
        function code(x)
        	tmp = 0.0
        	if (x <= 1.35)
        		tmp = fma(Float64(Float64(x * x) * x), fma(0.075, Float64(x * x), -0.16666666666666666), x);
        	else
        		tmp = log(Float64(2.0 * x));
        	end
        	return tmp
        end
        
        code[x_] := If[LessEqual[x, 1.35], N[(N[(N[(x * x), $MachinePrecision] * x), $MachinePrecision] * N[(0.075 * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] + x), $MachinePrecision], N[Log[N[(2.0 * x), $MachinePrecision]], $MachinePrecision]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;x \leq 1.35:\\
        \;\;\;\;\mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)\\
        
        \mathbf{else}:\\
        \;\;\;\;\log \left(2 \cdot x\right)\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if x < 1.3500000000000001

          1. Initial program 8.5%

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

            \[\leadsto \color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right)} \]
          4. Step-by-step derivation
            1. +-commutativeN/A

              \[\leadsto x \cdot \color{blue}{\left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + 1\right)} \]
            2. distribute-lft-inN/A

              \[\leadsto \color{blue}{x \cdot \left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right) + x \cdot 1} \]
            3. associate-*r*N/A

              \[\leadsto \color{blue}{\left(x \cdot {x}^{2}\right) \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)} + x \cdot 1 \]
            4. *-rgt-identityN/A

              \[\leadsto \left(x \cdot {x}^{2}\right) \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + \color{blue}{x} \]
            5. lower-fma.f64N/A

              \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot {x}^{2}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right)} \]
            6. *-commutativeN/A

              \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{2} \cdot x}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
            7. pow-plusN/A

              \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{\left(2 + 1\right)}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
            8. lower-pow.f64N/A

              \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{\left(2 + 1\right)}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
            9. metadata-evalN/A

              \[\leadsto \mathsf{fma}\left({x}^{\color{blue}{3}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
            10. sub-negN/A

              \[\leadsto \mathsf{fma}\left({x}^{3}, \color{blue}{\frac{3}{40} \cdot {x}^{2} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right)}, x\right) \]
            11. metadata-evalN/A

              \[\leadsto \mathsf{fma}\left({x}^{3}, \frac{3}{40} \cdot {x}^{2} + \color{blue}{\frac{-1}{6}}, x\right) \]
            12. lower-fma.f64N/A

              \[\leadsto \mathsf{fma}\left({x}^{3}, \color{blue}{\mathsf{fma}\left(\frac{3}{40}, {x}^{2}, \frac{-1}{6}\right)}, x\right) \]
            13. unpow2N/A

              \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(\frac{3}{40}, \color{blue}{x \cdot x}, \frac{-1}{6}\right), x\right) \]
            14. lower-*.f6464.5

              \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, \color{blue}{x \cdot x}, -0.16666666666666666\right), x\right) \]
          5. Applied rewrites64.5%

            \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)} \]
          6. Step-by-step derivation
            1. Applied rewrites64.5%

              \[\leadsto \mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(\color{blue}{0.075}, x \cdot x, -0.16666666666666666\right), x\right) \]

            if 1.3500000000000001 < x

            1. Initial program 48.3%

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

              \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
            4. Step-by-step derivation
              1. lower-*.f6499.1

                \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
            5. Applied rewrites99.1%

              \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
          7. Recombined 2 regimes into one program.
          8. Add Preprocessing

          Alternative 5: 58.7% accurate, 1.1× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.5:\\ \;\;\;\;\mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(1 + x\right)\\ \end{array} \end{array} \]
          (FPCore (x)
           :precision binary64
           (if (<= x 1.5)
             (fma (* (* x x) x) (fma 0.075 (* x x) -0.16666666666666666) x)
             (log (+ 1.0 x))))
          double code(double x) {
          	double tmp;
          	if (x <= 1.5) {
          		tmp = fma(((x * x) * x), fma(0.075, (x * x), -0.16666666666666666), x);
          	} else {
          		tmp = log((1.0 + x));
          	}
          	return tmp;
          }
          
          function code(x)
          	tmp = 0.0
          	if (x <= 1.5)
          		tmp = fma(Float64(Float64(x * x) * x), fma(0.075, Float64(x * x), -0.16666666666666666), x);
          	else
          		tmp = log(Float64(1.0 + x));
          	end
          	return tmp
          end
          
          code[x_] := If[LessEqual[x, 1.5], N[(N[(N[(x * x), $MachinePrecision] * x), $MachinePrecision] * N[(0.075 * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] + x), $MachinePrecision], N[Log[N[(1.0 + x), $MachinePrecision]], $MachinePrecision]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          \mathbf{if}\;x \leq 1.5:\\
          \;\;\;\;\mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)\\
          
          \mathbf{else}:\\
          \;\;\;\;\log \left(1 + x\right)\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if x < 1.5

            1. Initial program 8.5%

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

              \[\leadsto \color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right)} \]
            4. Step-by-step derivation
              1. +-commutativeN/A

                \[\leadsto x \cdot \color{blue}{\left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + 1\right)} \]
              2. distribute-lft-inN/A

                \[\leadsto \color{blue}{x \cdot \left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right) + x \cdot 1} \]
              3. associate-*r*N/A

                \[\leadsto \color{blue}{\left(x \cdot {x}^{2}\right) \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)} + x \cdot 1 \]
              4. *-rgt-identityN/A

                \[\leadsto \left(x \cdot {x}^{2}\right) \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + \color{blue}{x} \]
              5. lower-fma.f64N/A

                \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot {x}^{2}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right)} \]
              6. *-commutativeN/A

                \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{2} \cdot x}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
              7. pow-plusN/A

                \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{\left(2 + 1\right)}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
              8. lower-pow.f64N/A

                \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{\left(2 + 1\right)}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
              9. metadata-evalN/A

                \[\leadsto \mathsf{fma}\left({x}^{\color{blue}{3}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
              10. sub-negN/A

                \[\leadsto \mathsf{fma}\left({x}^{3}, \color{blue}{\frac{3}{40} \cdot {x}^{2} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right)}, x\right) \]
              11. metadata-evalN/A

                \[\leadsto \mathsf{fma}\left({x}^{3}, \frac{3}{40} \cdot {x}^{2} + \color{blue}{\frac{-1}{6}}, x\right) \]
              12. lower-fma.f64N/A

                \[\leadsto \mathsf{fma}\left({x}^{3}, \color{blue}{\mathsf{fma}\left(\frac{3}{40}, {x}^{2}, \frac{-1}{6}\right)}, x\right) \]
              13. unpow2N/A

                \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(\frac{3}{40}, \color{blue}{x \cdot x}, \frac{-1}{6}\right), x\right) \]
              14. lower-*.f6464.5

                \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, \color{blue}{x \cdot x}, -0.16666666666666666\right), x\right) \]
            5. Applied rewrites64.5%

              \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)} \]
            6. Step-by-step derivation
              1. Applied rewrites64.5%

                \[\leadsto \mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(\color{blue}{0.075}, x \cdot x, -0.16666666666666666\right), x\right) \]

              if 1.5 < x

              1. Initial program 48.3%

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

                \[\leadsto \log \color{blue}{\left(1 + x\right)} \]
              4. Step-by-step derivation
                1. lower-+.f6431.3

                  \[\leadsto \log \color{blue}{\left(1 + x\right)} \]
              5. Applied rewrites31.3%

                \[\leadsto \log \color{blue}{\left(1 + x\right)} \]
            7. Recombined 2 regimes into one program.
            8. Add Preprocessing

            Alternative 6: 51.4% accurate, 4.4× speedup?

            \[\begin{array}{l} \\ \mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right) \end{array} \]
            (FPCore (x)
             :precision binary64
             (fma (* (* x x) x) (fma 0.075 (* x x) -0.16666666666666666) x))
            double code(double x) {
            	return fma(((x * x) * x), fma(0.075, (x * x), -0.16666666666666666), x);
            }
            
            function code(x)
            	return fma(Float64(Float64(x * x) * x), fma(0.075, Float64(x * x), -0.16666666666666666), x)
            end
            
            code[x_] := N[(N[(N[(x * x), $MachinePrecision] * x), $MachinePrecision] * N[(0.075 * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] + x), $MachinePrecision]
            
            \begin{array}{l}
            
            \\
            \mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)
            \end{array}
            
            Derivation
            1. Initial program 17.9%

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

              \[\leadsto \color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right)} \]
            4. Step-by-step derivation
              1. +-commutativeN/A

                \[\leadsto x \cdot \color{blue}{\left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + 1\right)} \]
              2. distribute-lft-inN/A

                \[\leadsto \color{blue}{x \cdot \left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right) + x \cdot 1} \]
              3. associate-*r*N/A

                \[\leadsto \color{blue}{\left(x \cdot {x}^{2}\right) \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)} + x \cdot 1 \]
              4. *-rgt-identityN/A

                \[\leadsto \left(x \cdot {x}^{2}\right) \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + \color{blue}{x} \]
              5. lower-fma.f64N/A

                \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot {x}^{2}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right)} \]
              6. *-commutativeN/A

                \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{2} \cdot x}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
              7. pow-plusN/A

                \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{\left(2 + 1\right)}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
              8. lower-pow.f64N/A

                \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{\left(2 + 1\right)}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
              9. metadata-evalN/A

                \[\leadsto \mathsf{fma}\left({x}^{\color{blue}{3}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
              10. sub-negN/A

                \[\leadsto \mathsf{fma}\left({x}^{3}, \color{blue}{\frac{3}{40} \cdot {x}^{2} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right)}, x\right) \]
              11. metadata-evalN/A

                \[\leadsto \mathsf{fma}\left({x}^{3}, \frac{3}{40} \cdot {x}^{2} + \color{blue}{\frac{-1}{6}}, x\right) \]
              12. lower-fma.f64N/A

                \[\leadsto \mathsf{fma}\left({x}^{3}, \color{blue}{\mathsf{fma}\left(\frac{3}{40}, {x}^{2}, \frac{-1}{6}\right)}, x\right) \]
              13. unpow2N/A

                \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(\frac{3}{40}, \color{blue}{x \cdot x}, \frac{-1}{6}\right), x\right) \]
              14. lower-*.f6450.2

                \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, \color{blue}{x \cdot x}, -0.16666666666666666\right), x\right) \]
            5. Applied rewrites50.2%

              \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)} \]
            6. Step-by-step derivation
              1. Applied rewrites50.2%

                \[\leadsto \mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(\color{blue}{0.075}, x \cdot x, -0.16666666666666666\right), x\right) \]
              2. Add Preprocessing

              Alternative 7: 51.1% accurate, 4.5× speedup?

              \[\begin{array}{l} \\ \mathsf{fma}\left(\left(0.075 \cdot \left(x \cdot x\right)\right) \cdot x, x \cdot x, x\right) \end{array} \]
              (FPCore (x) :precision binary64 (fma (* (* 0.075 (* x x)) x) (* x x) x))
              double code(double x) {
              	return fma(((0.075 * (x * x)) * x), (x * x), x);
              }
              
              function code(x)
              	return fma(Float64(Float64(0.075 * Float64(x * x)) * x), Float64(x * x), x)
              end
              
              code[x_] := N[(N[(N[(0.075 * N[(x * x), $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision] * N[(x * x), $MachinePrecision] + x), $MachinePrecision]
              
              \begin{array}{l}
              
              \\
              \mathsf{fma}\left(\left(0.075 \cdot \left(x \cdot x\right)\right) \cdot x, x \cdot x, x\right)
              \end{array}
              
              Derivation
              1. Initial program 17.9%

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

                \[\leadsto \color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right)} \]
              4. Step-by-step derivation
                1. +-commutativeN/A

                  \[\leadsto x \cdot \color{blue}{\left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + 1\right)} \]
                2. distribute-lft-inN/A

                  \[\leadsto \color{blue}{x \cdot \left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right) + x \cdot 1} \]
                3. associate-*r*N/A

                  \[\leadsto \color{blue}{\left(x \cdot {x}^{2}\right) \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)} + x \cdot 1 \]
                4. *-rgt-identityN/A

                  \[\leadsto \left(x \cdot {x}^{2}\right) \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + \color{blue}{x} \]
                5. lower-fma.f64N/A

                  \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot {x}^{2}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right)} \]
                6. *-commutativeN/A

                  \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{2} \cdot x}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
                7. pow-plusN/A

                  \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{\left(2 + 1\right)}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
                8. lower-pow.f64N/A

                  \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{\left(2 + 1\right)}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
                9. metadata-evalN/A

                  \[\leadsto \mathsf{fma}\left({x}^{\color{blue}{3}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
                10. sub-negN/A

                  \[\leadsto \mathsf{fma}\left({x}^{3}, \color{blue}{\frac{3}{40} \cdot {x}^{2} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right)}, x\right) \]
                11. metadata-evalN/A

                  \[\leadsto \mathsf{fma}\left({x}^{3}, \frac{3}{40} \cdot {x}^{2} + \color{blue}{\frac{-1}{6}}, x\right) \]
                12. lower-fma.f64N/A

                  \[\leadsto \mathsf{fma}\left({x}^{3}, \color{blue}{\mathsf{fma}\left(\frac{3}{40}, {x}^{2}, \frac{-1}{6}\right)}, x\right) \]
                13. unpow2N/A

                  \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(\frac{3}{40}, \color{blue}{x \cdot x}, \frac{-1}{6}\right), x\right) \]
                14. lower-*.f6450.2

                  \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, \color{blue}{x \cdot x}, -0.16666666666666666\right), x\right) \]
              5. Applied rewrites50.2%

                \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)} \]
              6. Step-by-step derivation
                1. Applied rewrites50.2%

                  \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, 0.075, -0.16666666666666666\right) \cdot x, \color{blue}{x \cdot x}, x\right) \]
                2. Taylor expanded in x around inf

                  \[\leadsto \mathsf{fma}\left(\left(\frac{3}{40} \cdot {x}^{2}\right) \cdot x, x \cdot x, x\right) \]
                3. Step-by-step derivation
                  1. Applied rewrites49.7%

                    \[\leadsto \mathsf{fma}\left(\left(0.075 \cdot \left(x \cdot x\right)\right) \cdot x, x \cdot x, x\right) \]
                  2. Add Preprocessing

                  Alternative 8: 49.9% accurate, 7.2× speedup?

                  \[\begin{array}{l} \\ \mathsf{fma}\left(-0.16666666666666666 \cdot x, x, 1\right) \cdot x \end{array} \]
                  (FPCore (x) :precision binary64 (* (fma (* -0.16666666666666666 x) x 1.0) x))
                  double code(double x) {
                  	return fma((-0.16666666666666666 * x), x, 1.0) * x;
                  }
                  
                  function code(x)
                  	return Float64(fma(Float64(-0.16666666666666666 * x), x, 1.0) * x)
                  end
                  
                  code[x_] := N[(N[(N[(-0.16666666666666666 * x), $MachinePrecision] * x + 1.0), $MachinePrecision] * x), $MachinePrecision]
                  
                  \begin{array}{l}
                  
                  \\
                  \mathsf{fma}\left(-0.16666666666666666 \cdot x, x, 1\right) \cdot x
                  \end{array}
                  
                  Derivation
                  1. Initial program 17.9%

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

                    \[\leadsto \color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right)} \]
                  4. Step-by-step derivation
                    1. +-commutativeN/A

                      \[\leadsto x \cdot \color{blue}{\left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + 1\right)} \]
                    2. distribute-lft-inN/A

                      \[\leadsto \color{blue}{x \cdot \left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right) + x \cdot 1} \]
                    3. associate-*r*N/A

                      \[\leadsto \color{blue}{\left(x \cdot {x}^{2}\right) \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)} + x \cdot 1 \]
                    4. *-rgt-identityN/A

                      \[\leadsto \left(x \cdot {x}^{2}\right) \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + \color{blue}{x} \]
                    5. lower-fma.f64N/A

                      \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot {x}^{2}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right)} \]
                    6. *-commutativeN/A

                      \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{2} \cdot x}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
                    7. pow-plusN/A

                      \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{\left(2 + 1\right)}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
                    8. lower-pow.f64N/A

                      \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{\left(2 + 1\right)}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
                    9. metadata-evalN/A

                      \[\leadsto \mathsf{fma}\left({x}^{\color{blue}{3}}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, x\right) \]
                    10. sub-negN/A

                      \[\leadsto \mathsf{fma}\left({x}^{3}, \color{blue}{\frac{3}{40} \cdot {x}^{2} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right)}, x\right) \]
                    11. metadata-evalN/A

                      \[\leadsto \mathsf{fma}\left({x}^{3}, \frac{3}{40} \cdot {x}^{2} + \color{blue}{\frac{-1}{6}}, x\right) \]
                    12. lower-fma.f64N/A

                      \[\leadsto \mathsf{fma}\left({x}^{3}, \color{blue}{\mathsf{fma}\left(\frac{3}{40}, {x}^{2}, \frac{-1}{6}\right)}, x\right) \]
                    13. unpow2N/A

                      \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(\frac{3}{40}, \color{blue}{x \cdot x}, \frac{-1}{6}\right), x\right) \]
                    14. lower-*.f6450.2

                      \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, \color{blue}{x \cdot x}, -0.16666666666666666\right), x\right) \]
                  5. Applied rewrites50.2%

                    \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)} \]
                  6. Step-by-step derivation
                    1. Applied rewrites50.2%

                      \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, 0.075, -0.16666666666666666\right) \cdot x, \color{blue}{x \cdot x}, x\right) \]
                    2. Taylor expanded in x around 0

                      \[\leadsto \mathsf{fma}\left(\frac{-1}{6} \cdot x, x \cdot x, x\right) \]
                    3. Step-by-step derivation
                      1. Applied rewrites48.6%

                        \[\leadsto \mathsf{fma}\left(-0.16666666666666666 \cdot x, x \cdot x, x\right) \]
                      2. Step-by-step derivation
                        1. Applied rewrites48.6%

                          \[\leadsto \mathsf{fma}\left(-0.16666666666666666 \cdot x, x, 1\right) \cdot \color{blue}{x} \]
                        2. Add Preprocessing

                        Developer Target 1: 30.8% accurate, 0.9× 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 2024323 
                        (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)))))