Numeric.SpecFunctions:invIncompleteGamma from math-functions-0.1.5.2, B

Percentage Accurate: 72.3% → 99.6%
Time: 13.5s
Alternatives: 10
Speedup: 1.0×

Specification

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

\\
1 - \log \left(1 - \frac{x - y}{1 - y}\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 10 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: 72.3% accurate, 1.0× speedup?

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

\\
1 - \log \left(1 - \frac{x - y}{1 - y}\right)
\end{array}

Alternative 1: 99.6% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -13600:\\ \;\;\;\;1 + \left(\frac{-1 + \frac{-0.5}{y}}{y} - \left(\log \left(1 - x\right) + \log \left(\frac{-1}{y}\right)\right)\right)\\ \mathbf{elif}\;y \leq 5 \cdot 10^{+14}:\\ \;\;\;\;1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= y -13600.0)
   (+ 1.0 (- (/ (+ -1.0 (/ -0.5 y)) y) (+ (log (- 1.0 x)) (log (/ -1.0 y)))))
   (if (<= y 5e+14)
     (- 1.0 (log1p (/ (- x y) (+ y -1.0))))
     (- 1.0 (log (/ x y))))))
double code(double x, double y) {
	double tmp;
	if (y <= -13600.0) {
		tmp = 1.0 + (((-1.0 + (-0.5 / y)) / y) - (log((1.0 - x)) + log((-1.0 / y))));
	} else if (y <= 5e+14) {
		tmp = 1.0 - log1p(((x - y) / (y + -1.0)));
	} else {
		tmp = 1.0 - log((x / y));
	}
	return tmp;
}
public static double code(double x, double y) {
	double tmp;
	if (y <= -13600.0) {
		tmp = 1.0 + (((-1.0 + (-0.5 / y)) / y) - (Math.log((1.0 - x)) + Math.log((-1.0 / y))));
	} else if (y <= 5e+14) {
		tmp = 1.0 - Math.log1p(((x - y) / (y + -1.0)));
	} else {
		tmp = 1.0 - Math.log((x / y));
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if y <= -13600.0:
		tmp = 1.0 + (((-1.0 + (-0.5 / y)) / y) - (math.log((1.0 - x)) + math.log((-1.0 / y))))
	elif y <= 5e+14:
		tmp = 1.0 - math.log1p(((x - y) / (y + -1.0)))
	else:
		tmp = 1.0 - math.log((x / y))
	return tmp
function code(x, y)
	tmp = 0.0
	if (y <= -13600.0)
		tmp = Float64(1.0 + Float64(Float64(Float64(-1.0 + Float64(-0.5 / y)) / y) - Float64(log(Float64(1.0 - x)) + log(Float64(-1.0 / y)))));
	elseif (y <= 5e+14)
		tmp = Float64(1.0 - log1p(Float64(Float64(x - y) / Float64(y + -1.0))));
	else
		tmp = Float64(1.0 - log(Float64(x / y)));
	end
	return tmp
end
code[x_, y_] := If[LessEqual[y, -13600.0], N[(1.0 + N[(N[(N[(-1.0 + N[(-0.5 / y), $MachinePrecision]), $MachinePrecision] / y), $MachinePrecision] - N[(N[Log[N[(1.0 - x), $MachinePrecision]], $MachinePrecision] + N[Log[N[(-1.0 / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[y, 5e+14], N[(1.0 - N[Log[1 + N[(N[(x - y), $MachinePrecision] / N[(y + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -13600:\\
\;\;\;\;1 + \left(\frac{-1 + \frac{-0.5}{y}}{y} - \left(\log \left(1 - x\right) + \log \left(\frac{-1}{y}\right)\right)\right)\\

\mathbf{elif}\;y \leq 5 \cdot 10^{+14}:\\
\;\;\;\;1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)\\

\mathbf{else}:\\
\;\;\;\;1 - \log \left(\frac{x}{y}\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y < -13600

    1. Initial program 20.8%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 - \frac{x - y}{1 - y}\right)}\right) \]
      2. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      3. log1p-defineN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \left(\mathsf{log1p}\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      4. log1p-lowering-log1p.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      5. distribute-neg-frac2N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
      6. /-lowering-/.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
      7. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
      8. neg-sub0N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(0 - \left(1 - y\right)\right)\right)\right)\right) \]
      9. associate--r-N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(0 - 1\right) + y\right)\right)\right)\right) \]
      10. metadata-evalN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
      11. +-commutativeN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
      12. +-lowering-+.f6420.8%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
    3. Simplified20.8%

      \[\leadsto \color{blue}{1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in y around -inf

      \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\left(\log \left(-1 \cdot \left(x - 1\right)\right) + \left(\log \left(\frac{-1}{y}\right) + -1 \cdot \frac{\left(\frac{-1}{2} \cdot \frac{2 + -1 \cdot \frac{{\left(1 - x\right)}^{2}}{{\left(x - 1\right)}^{2}}}{y} + \frac{1}{x - 1}\right) - \frac{x}{x - 1}}{y}\right)\right)}\right) \]
    6. Simplified99.5%

      \[\leadsto 1 - \color{blue}{\left(\left(\log \left(1 - x\right) + \log \left(\frac{-1}{y}\right)\right) - \frac{-1 + \frac{-0.5}{y}}{y}\right)} \]

    if -13600 < y < 5e14

    1. Initial program 100.0%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 - \frac{x - y}{1 - y}\right)}\right) \]
      2. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      3. log1p-defineN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \left(\mathsf{log1p}\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      4. log1p-lowering-log1p.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      5. distribute-neg-frac2N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
      6. /-lowering-/.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
      7. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
      8. neg-sub0N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(0 - \left(1 - y\right)\right)\right)\right)\right) \]
      9. associate--r-N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(0 - 1\right) + y\right)\right)\right)\right) \]
      10. metadata-evalN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
      11. +-commutativeN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
      12. +-lowering-+.f64100.0%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
    4. Add Preprocessing

    if 5e14 < y

    1. Initial program 36.3%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 - \frac{x - y}{1 - y}\right)}\right) \]
      2. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      3. log1p-defineN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \left(\mathsf{log1p}\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      4. log1p-lowering-log1p.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      5. distribute-neg-frac2N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
      6. /-lowering-/.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
      7. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
      8. neg-sub0N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(0 - \left(1 - y\right)\right)\right)\right)\right) \]
      9. associate--r-N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(0 - 1\right) + y\right)\right)\right)\right) \]
      10. metadata-evalN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
      11. +-commutativeN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
      12. +-lowering-+.f6436.3%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
    3. Simplified36.3%

      \[\leadsto \color{blue}{1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in y around inf

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \color{blue}{y}\right)\right)\right) \]
    6. Step-by-step derivation
      1. Simplified36.3%

        \[\leadsto 1 - \mathsf{log1p}\left(\frac{x - y}{\color{blue}{y}}\right) \]
      2. Step-by-step derivation
        1. --lowering--.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 + \frac{x - y}{y}\right)}\right) \]
        2. log-lowering-log.f64N/A

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

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x - y}{y} + 1\right)\right)\right) \]
        4. div-subN/A

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

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

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x}{y} - \left(1 - 1\right)\right)\right)\right) \]
        7. metadata-evalN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x}{y} - 0\right)\right)\right) \]
        8. --lowering--.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{\_.f64}\left(\left(\frac{x}{y}\right), 0\right)\right)\right) \]
        9. /-lowering-/.f64100.0%

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{\_.f64}\left(\mathsf{/.f64}\left(x, y\right), 0\right)\right)\right) \]
      3. Applied egg-rr100.0%

        \[\leadsto \color{blue}{1 - \log \left(\frac{x}{y} - 0\right)} \]
    7. Recombined 3 regimes into one program.
    8. Final simplification99.8%

      \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -13600:\\ \;\;\;\;1 + \left(\frac{-1 + \frac{-0.5}{y}}{y} - \left(\log \left(1 - x\right) + \log \left(\frac{-1}{y}\right)\right)\right)\\ \mathbf{elif}\;y \leq 5 \cdot 10^{+14}:\\ \;\;\;\;1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\ \end{array} \]
    9. Add Preprocessing

    Alternative 2: 99.2% accurate, 0.5× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -3.2 \cdot 10^{+18}:\\ \;\;\;\;\left(1 - \log \left(1 - x\right)\right) - \log \left(\frac{-1}{y}\right)\\ \mathbf{elif}\;y \leq 5 \cdot 10^{+14}:\\ \;\;\;\;1 - \mathsf{log1p}\left(\frac{x - y}{\frac{1 - \left(y \cdot y\right) \cdot \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right)\right)}{\left(-1 - y\right) \cdot \left(1 - \left(y \cdot y\right) \cdot \left(-1 - y \cdot y\right)\right)}}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\ \end{array} \end{array} \]
    (FPCore (x y)
     :precision binary64
     (if (<= y -3.2e+18)
       (- (- 1.0 (log (- 1.0 x))) (log (/ -1.0 y)))
       (if (<= y 5e+14)
         (-
          1.0
          (log1p
           (/
            (- x y)
            (/
             (- 1.0 (* (* y y) (* (* y y) (* y y))))
             (* (- -1.0 y) (- 1.0 (* (* y y) (- -1.0 (* y y)))))))))
         (- 1.0 (log (/ x y))))))
    double code(double x, double y) {
    	double tmp;
    	if (y <= -3.2e+18) {
    		tmp = (1.0 - log((1.0 - x))) - log((-1.0 / y));
    	} else if (y <= 5e+14) {
    		tmp = 1.0 - log1p(((x - y) / ((1.0 - ((y * y) * ((y * y) * (y * y)))) / ((-1.0 - y) * (1.0 - ((y * y) * (-1.0 - (y * y))))))));
    	} else {
    		tmp = 1.0 - log((x / y));
    	}
    	return tmp;
    }
    
    public static double code(double x, double y) {
    	double tmp;
    	if (y <= -3.2e+18) {
    		tmp = (1.0 - Math.log((1.0 - x))) - Math.log((-1.0 / y));
    	} else if (y <= 5e+14) {
    		tmp = 1.0 - Math.log1p(((x - y) / ((1.0 - ((y * y) * ((y * y) * (y * y)))) / ((-1.0 - y) * (1.0 - ((y * y) * (-1.0 - (y * y))))))));
    	} else {
    		tmp = 1.0 - Math.log((x / y));
    	}
    	return tmp;
    }
    
    def code(x, y):
    	tmp = 0
    	if y <= -3.2e+18:
    		tmp = (1.0 - math.log((1.0 - x))) - math.log((-1.0 / y))
    	elif y <= 5e+14:
    		tmp = 1.0 - math.log1p(((x - y) / ((1.0 - ((y * y) * ((y * y) * (y * y)))) / ((-1.0 - y) * (1.0 - ((y * y) * (-1.0 - (y * y))))))))
    	else:
    		tmp = 1.0 - math.log((x / y))
    	return tmp
    
    function code(x, y)
    	tmp = 0.0
    	if (y <= -3.2e+18)
    		tmp = Float64(Float64(1.0 - log(Float64(1.0 - x))) - log(Float64(-1.0 / y)));
    	elseif (y <= 5e+14)
    		tmp = Float64(1.0 - log1p(Float64(Float64(x - y) / Float64(Float64(1.0 - Float64(Float64(y * y) * Float64(Float64(y * y) * Float64(y * y)))) / Float64(Float64(-1.0 - y) * Float64(1.0 - Float64(Float64(y * y) * Float64(-1.0 - Float64(y * y)))))))));
    	else
    		tmp = Float64(1.0 - log(Float64(x / y)));
    	end
    	return tmp
    end
    
    code[x_, y_] := If[LessEqual[y, -3.2e+18], N[(N[(1.0 - N[Log[N[(1.0 - x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - N[Log[N[(-1.0 / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[y, 5e+14], N[(1.0 - N[Log[1 + N[(N[(x - y), $MachinePrecision] / N[(N[(1.0 - N[(N[(y * y), $MachinePrecision] * N[(N[(y * y), $MachinePrecision] * N[(y * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(-1.0 - y), $MachinePrecision] * N[(1.0 - N[(N[(y * y), $MachinePrecision] * N[(-1.0 - N[(y * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;y \leq -3.2 \cdot 10^{+18}:\\
    \;\;\;\;\left(1 - \log \left(1 - x\right)\right) - \log \left(\frac{-1}{y}\right)\\
    
    \mathbf{elif}\;y \leq 5 \cdot 10^{+14}:\\
    \;\;\;\;1 - \mathsf{log1p}\left(\frac{x - y}{\frac{1 - \left(y \cdot y\right) \cdot \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right)\right)}{\left(-1 - y\right) \cdot \left(1 - \left(y \cdot y\right) \cdot \left(-1 - y \cdot y\right)\right)}}\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if y < -3.2e18

      1. Initial program 15.6%

        \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
      2. Step-by-step derivation
        1. --lowering--.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 - \frac{x - y}{1 - y}\right)}\right) \]
        2. sub-negN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
        3. log1p-defineN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \left(\mathsf{log1p}\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
        4. log1p-lowering-log1p.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
        5. distribute-neg-frac2N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
        6. /-lowering-/.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
        7. --lowering--.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
        8. neg-sub0N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(0 - \left(1 - y\right)\right)\right)\right)\right) \]
        9. associate--r-N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(0 - 1\right) + y\right)\right)\right)\right) \]
        10. metadata-evalN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
        11. +-commutativeN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
        12. +-lowering-+.f6415.6%

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
      3. Simplified15.6%

        \[\leadsto \color{blue}{1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in y around -inf

        \[\leadsto \color{blue}{1 - \left(\log \left(-1 \cdot \left(x - 1\right)\right) + \log \left(\frac{-1}{y}\right)\right)} \]
      6. Simplified99.5%

        \[\leadsto \color{blue}{\left(1 - \log \left(1 - x\right)\right) - \log \left(\frac{-1}{y}\right)} \]

      if -3.2e18 < y < 5e14

      1. Initial program 99.9%

        \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
      2. Step-by-step derivation
        1. --lowering--.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 - \frac{x - y}{1 - y}\right)}\right) \]
        2. sub-negN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
        3. log1p-defineN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \left(\mathsf{log1p}\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
        4. log1p-lowering-log1p.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
        5. distribute-neg-frac2N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
        6. /-lowering-/.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
        7. --lowering--.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
        8. neg-sub0N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(0 - \left(1 - y\right)\right)\right)\right)\right) \]
        9. associate--r-N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(0 - 1\right) + y\right)\right)\right)\right) \]
        10. metadata-evalN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
        11. +-commutativeN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
        12. +-lowering-+.f6499.9%

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
      3. Simplified99.9%

        \[\leadsto \color{blue}{1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
      4. Add Preprocessing
      5. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
        2. flip-+N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\frac{-1 \cdot -1 - y \cdot y}{-1 - y}\right)\right)\right)\right) \]
        3. div-invN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(-1 \cdot -1 - y \cdot y\right) \cdot \frac{1}{-1 - y}\right)\right)\right)\right) \]
        4. *-lowering-*.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{*.f64}\left(\left(-1 \cdot -1 - y \cdot y\right), \left(\frac{1}{-1 - y}\right)\right)\right)\right)\right) \]
        5. metadata-evalN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{*.f64}\left(\left(1 - y \cdot y\right), \left(\frac{1}{-1 - y}\right)\right)\right)\right)\right) \]
        6. --lowering--.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{*.f64}\left(\mathsf{\_.f64}\left(1, \left(y \cdot y\right)\right), \left(\frac{1}{-1 - y}\right)\right)\right)\right)\right) \]
        7. *-lowering-*.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{*.f64}\left(\mathsf{\_.f64}\left(1, \mathsf{*.f64}\left(y, y\right)\right), \left(\frac{1}{-1 - y}\right)\right)\right)\right)\right) \]
        8. /-lowering-/.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{*.f64}\left(\mathsf{\_.f64}\left(1, \mathsf{*.f64}\left(y, y\right)\right), \mathsf{/.f64}\left(1, \left(-1 - y\right)\right)\right)\right)\right)\right) \]
        9. --lowering--.f6499.9%

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{*.f64}\left(\mathsf{\_.f64}\left(1, \mathsf{*.f64}\left(y, y\right)\right), \mathsf{/.f64}\left(1, \mathsf{\_.f64}\left(-1, y\right)\right)\right)\right)\right)\right) \]
      6. Applied egg-rr99.9%

        \[\leadsto 1 - \mathsf{log1p}\left(\frac{x - y}{\color{blue}{\left(1 - y \cdot y\right) \cdot \frac{1}{-1 - y}}}\right) \]
      7. Step-by-step derivation
        1. un-div-invN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\frac{1 - y \cdot y}{-1 - y}\right)\right)\right)\right) \]
        2. flip3--N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\frac{\frac{{1}^{3} - {\left(y \cdot y\right)}^{3}}{1 \cdot 1 + \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right) + 1 \cdot \left(y \cdot y\right)\right)}}{-1 - y}\right)\right)\right)\right) \]
        3. associate-/l/N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\frac{{1}^{3} - {\left(y \cdot y\right)}^{3}}{\left(-1 - y\right) \cdot \left(1 \cdot 1 + \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right) + 1 \cdot \left(y \cdot y\right)\right)\right)}\right)\right)\right)\right) \]
        4. /-lowering-/.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{/.f64}\left(\left({1}^{3} - {\left(y \cdot y\right)}^{3}\right), \left(\left(-1 - y\right) \cdot \left(1 \cdot 1 + \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right) + 1 \cdot \left(y \cdot y\right)\right)\right)\right)\right)\right)\right)\right) \]
        5. metadata-evalN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{/.f64}\left(\left(1 - {\left(y \cdot y\right)}^{3}\right), \left(\left(-1 - y\right) \cdot \left(1 \cdot 1 + \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right) + 1 \cdot \left(y \cdot y\right)\right)\right)\right)\right)\right)\right)\right) \]
        6. --lowering--.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{/.f64}\left(\mathsf{\_.f64}\left(1, \left({\left(y \cdot y\right)}^{3}\right)\right), \left(\left(-1 - y\right) \cdot \left(1 \cdot 1 + \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right) + 1 \cdot \left(y \cdot y\right)\right)\right)\right)\right)\right)\right)\right) \]
        7. cube-multN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{/.f64}\left(\mathsf{\_.f64}\left(1, \left(\left(y \cdot y\right) \cdot \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right)\right)\right)\right), \left(\left(-1 - y\right) \cdot \left(1 \cdot 1 + \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right) + 1 \cdot \left(y \cdot y\right)\right)\right)\right)\right)\right)\right)\right) \]
        8. *-lowering-*.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{/.f64}\left(\mathsf{\_.f64}\left(1, \mathsf{*.f64}\left(\left(y \cdot y\right), \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right)\right)\right)\right), \left(\left(-1 - y\right) \cdot \left(1 \cdot 1 + \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right) + 1 \cdot \left(y \cdot y\right)\right)\right)\right)\right)\right)\right)\right) \]
        9. *-lowering-*.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{/.f64}\left(\mathsf{\_.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(y, y\right), \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right)\right)\right)\right), \left(\left(-1 - y\right) \cdot \left(1 \cdot 1 + \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right) + 1 \cdot \left(y \cdot y\right)\right)\right)\right)\right)\right)\right)\right) \]
        10. *-lowering-*.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{/.f64}\left(\mathsf{\_.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(y, y\right), \mathsf{*.f64}\left(\left(y \cdot y\right), \left(y \cdot y\right)\right)\right)\right), \left(\left(-1 - y\right) \cdot \left(1 \cdot 1 + \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right) + 1 \cdot \left(y \cdot y\right)\right)\right)\right)\right)\right)\right)\right) \]
        11. *-lowering-*.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{/.f64}\left(\mathsf{\_.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(y, y\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(y, y\right), \left(y \cdot y\right)\right)\right)\right), \left(\left(-1 - y\right) \cdot \left(1 \cdot 1 + \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right) + 1 \cdot \left(y \cdot y\right)\right)\right)\right)\right)\right)\right)\right) \]
        12. *-lowering-*.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{/.f64}\left(\mathsf{\_.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(y, y\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(y, y\right), \mathsf{*.f64}\left(y, y\right)\right)\right)\right), \left(\left(-1 - y\right) \cdot \left(1 \cdot 1 + \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right) + 1 \cdot \left(y \cdot y\right)\right)\right)\right)\right)\right)\right)\right) \]
        13. *-lowering-*.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{/.f64}\left(\mathsf{\_.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(y, y\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(y, y\right), \mathsf{*.f64}\left(y, y\right)\right)\right)\right), \mathsf{*.f64}\left(\left(-1 - y\right), \left(1 \cdot 1 + \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right) + 1 \cdot \left(y \cdot y\right)\right)\right)\right)\right)\right)\right)\right) \]
        14. --lowering--.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{/.f64}\left(\mathsf{\_.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(y, y\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(y, y\right), \mathsf{*.f64}\left(y, y\right)\right)\right)\right), \mathsf{*.f64}\left(\mathsf{\_.f64}\left(-1, y\right), \left(1 \cdot 1 + \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right) + 1 \cdot \left(y \cdot y\right)\right)\right)\right)\right)\right)\right)\right) \]
        15. metadata-evalN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{/.f64}\left(\mathsf{\_.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(y, y\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(y, y\right), \mathsf{*.f64}\left(y, y\right)\right)\right)\right), \mathsf{*.f64}\left(\mathsf{\_.f64}\left(-1, y\right), \left(1 + \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right) + 1 \cdot \left(y \cdot y\right)\right)\right)\right)\right)\right)\right)\right) \]
        16. +-lowering-+.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{/.f64}\left(\mathsf{\_.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(y, y\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(y, y\right), \mathsf{*.f64}\left(y, y\right)\right)\right)\right), \mathsf{*.f64}\left(\mathsf{\_.f64}\left(-1, y\right), \mathsf{+.f64}\left(1, \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right) + 1 \cdot \left(y \cdot y\right)\right)\right)\right)\right)\right)\right)\right) \]
      8. Applied egg-rr99.9%

        \[\leadsto 1 - \mathsf{log1p}\left(\frac{x - y}{\color{blue}{\frac{1 - \left(y \cdot y\right) \cdot \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right)\right)}{\left(-1 - y\right) \cdot \left(1 + \left(y \cdot y\right) \cdot \left(1 + y \cdot y\right)\right)}}}\right) \]

      if 5e14 < y

      1. Initial program 36.3%

        \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
      2. Step-by-step derivation
        1. --lowering--.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 - \frac{x - y}{1 - y}\right)}\right) \]
        2. sub-negN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
        3. log1p-defineN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \left(\mathsf{log1p}\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
        4. log1p-lowering-log1p.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
        5. distribute-neg-frac2N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
        6. /-lowering-/.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
        7. --lowering--.f64N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
        8. neg-sub0N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(0 - \left(1 - y\right)\right)\right)\right)\right) \]
        9. associate--r-N/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(0 - 1\right) + y\right)\right)\right)\right) \]
        10. metadata-evalN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
        11. +-commutativeN/A

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
        12. +-lowering-+.f6436.3%

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
      3. Simplified36.3%

        \[\leadsto \color{blue}{1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in y around inf

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \color{blue}{y}\right)\right)\right) \]
      6. Step-by-step derivation
        1. Simplified36.3%

          \[\leadsto 1 - \mathsf{log1p}\left(\frac{x - y}{\color{blue}{y}}\right) \]
        2. Step-by-step derivation
          1. --lowering--.f64N/A

            \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 + \frac{x - y}{y}\right)}\right) \]
          2. log-lowering-log.f64N/A

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

            \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x - y}{y} + 1\right)\right)\right) \]
          4. div-subN/A

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

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

            \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x}{y} - \left(1 - 1\right)\right)\right)\right) \]
          7. metadata-evalN/A

            \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x}{y} - 0\right)\right)\right) \]
          8. --lowering--.f64N/A

            \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{\_.f64}\left(\left(\frac{x}{y}\right), 0\right)\right)\right) \]
          9. /-lowering-/.f64100.0%

            \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{\_.f64}\left(\mathsf{/.f64}\left(x, y\right), 0\right)\right)\right) \]
        3. Applied egg-rr100.0%

          \[\leadsto \color{blue}{1 - \log \left(\frac{x}{y} - 0\right)} \]
      7. Recombined 3 regimes into one program.
      8. Final simplification99.8%

        \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -3.2 \cdot 10^{+18}:\\ \;\;\;\;\left(1 - \log \left(1 - x\right)\right) - \log \left(\frac{-1}{y}\right)\\ \mathbf{elif}\;y \leq 5 \cdot 10^{+14}:\\ \;\;\;\;1 - \mathsf{log1p}\left(\frac{x - y}{\frac{1 - \left(y \cdot y\right) \cdot \left(\left(y \cdot y\right) \cdot \left(y \cdot y\right)\right)}{\left(-1 - y\right) \cdot \left(1 - \left(y \cdot y\right) \cdot \left(-1 - y \cdot y\right)\right)}}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\ \end{array} \]
      9. Add Preprocessing

      Alternative 3: 81.5% accurate, 0.9× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;1 + \frac{x - y}{y + -1} \leq 5 \cdot 10^{-7}:\\ \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \mathsf{log1p}\left(x \cdot \left(\frac{1}{y + -1} + \frac{\frac{y}{1 - y}}{x}\right)\right)\\ \end{array} \end{array} \]
      (FPCore (x y)
       :precision binary64
       (if (<= (+ 1.0 (/ (- x y) (+ y -1.0))) 5e-7)
         (- 1.0 (log (/ x y)))
         (- 1.0 (log1p (* x (+ (/ 1.0 (+ y -1.0)) (/ (/ y (- 1.0 y)) x)))))))
      double code(double x, double y) {
      	double tmp;
      	if ((1.0 + ((x - y) / (y + -1.0))) <= 5e-7) {
      		tmp = 1.0 - log((x / y));
      	} else {
      		tmp = 1.0 - log1p((x * ((1.0 / (y + -1.0)) + ((y / (1.0 - y)) / x))));
      	}
      	return tmp;
      }
      
      public static double code(double x, double y) {
      	double tmp;
      	if ((1.0 + ((x - y) / (y + -1.0))) <= 5e-7) {
      		tmp = 1.0 - Math.log((x / y));
      	} else {
      		tmp = 1.0 - Math.log1p((x * ((1.0 / (y + -1.0)) + ((y / (1.0 - y)) / x))));
      	}
      	return tmp;
      }
      
      def code(x, y):
      	tmp = 0
      	if (1.0 + ((x - y) / (y + -1.0))) <= 5e-7:
      		tmp = 1.0 - math.log((x / y))
      	else:
      		tmp = 1.0 - math.log1p((x * ((1.0 / (y + -1.0)) + ((y / (1.0 - y)) / x))))
      	return tmp
      
      function code(x, y)
      	tmp = 0.0
      	if (Float64(1.0 + Float64(Float64(x - y) / Float64(y + -1.0))) <= 5e-7)
      		tmp = Float64(1.0 - log(Float64(x / y)));
      	else
      		tmp = Float64(1.0 - log1p(Float64(x * Float64(Float64(1.0 / Float64(y + -1.0)) + Float64(Float64(y / Float64(1.0 - y)) / x)))));
      	end
      	return tmp
      end
      
      code[x_, y_] := If[LessEqual[N[(1.0 + N[(N[(x - y), $MachinePrecision] / N[(y + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 5e-7], N[(1.0 - N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Log[1 + N[(x * N[(N[(1.0 / N[(y + -1.0), $MachinePrecision]), $MachinePrecision] + N[(N[(y / N[(1.0 - y), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;1 + \frac{x - y}{y + -1} \leq 5 \cdot 10^{-7}:\\
      \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;1 - \mathsf{log1p}\left(x \cdot \left(\frac{1}{y + -1} + \frac{\frac{y}{1 - y}}{x}\right)\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (-.f64 #s(literal 1 binary64) (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y))) < 4.99999999999999977e-7

        1. Initial program 5.4%

          \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
        2. Step-by-step derivation
          1. --lowering--.f64N/A

            \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 - \frac{x - y}{1 - y}\right)}\right) \]
          2. sub-negN/A

            \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
          3. log1p-defineN/A

            \[\leadsto \mathsf{\_.f64}\left(1, \left(\mathsf{log1p}\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
          4. log1p-lowering-log1p.f64N/A

            \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
          5. distribute-neg-frac2N/A

            \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
          6. /-lowering-/.f64N/A

            \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
          7. --lowering--.f64N/A

            \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
          8. neg-sub0N/A

            \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(0 - \left(1 - y\right)\right)\right)\right)\right) \]
          9. associate--r-N/A

            \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(0 - 1\right) + y\right)\right)\right)\right) \]
          10. metadata-evalN/A

            \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
          11. +-commutativeN/A

            \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
          12. +-lowering-+.f645.4%

            \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
        3. Simplified5.4%

          \[\leadsto \color{blue}{1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
        4. Add Preprocessing
        5. Taylor expanded in y around inf

          \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \color{blue}{y}\right)\right)\right) \]
        6. Step-by-step derivation
          1. Simplified5.4%

            \[\leadsto 1 - \mathsf{log1p}\left(\frac{x - y}{\color{blue}{y}}\right) \]
          2. Step-by-step derivation
            1. --lowering--.f64N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 + \frac{x - y}{y}\right)}\right) \]
            2. log-lowering-log.f64N/A

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

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x - y}{y} + 1\right)\right)\right) \]
            4. div-subN/A

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

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

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x}{y} - \left(1 - 1\right)\right)\right)\right) \]
            7. metadata-evalN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x}{y} - 0\right)\right)\right) \]
            8. --lowering--.f64N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{\_.f64}\left(\left(\frac{x}{y}\right), 0\right)\right)\right) \]
            9. /-lowering-/.f6432.5%

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{\_.f64}\left(\mathsf{/.f64}\left(x, y\right), 0\right)\right)\right) \]
          3. Applied egg-rr32.5%

            \[\leadsto \color{blue}{1 - \log \left(\frac{x}{y} - 0\right)} \]

          if 4.99999999999999977e-7 < (-.f64 #s(literal 1 binary64) (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y)))

          1. Initial program 99.9%

            \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
          2. Step-by-step derivation
            1. --lowering--.f64N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 - \frac{x - y}{1 - y}\right)}\right) \]
            2. sub-negN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
            3. log1p-defineN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \left(\mathsf{log1p}\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
            4. log1p-lowering-log1p.f64N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
            5. distribute-neg-frac2N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
            6. /-lowering-/.f64N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
            7. --lowering--.f64N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
            8. neg-sub0N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(0 - \left(1 - y\right)\right)\right)\right)\right) \]
            9. associate--r-N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(0 - 1\right) + y\right)\right)\right)\right) \]
            10. metadata-evalN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
            11. +-commutativeN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
            12. +-lowering-+.f6499.9%

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
          3. Simplified99.9%

            \[\leadsto \color{blue}{1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
          4. Add Preprocessing
          5. Taylor expanded in x around inf

            \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\color{blue}{\left(x \cdot \left(-1 \cdot \frac{y}{x \cdot \left(y - 1\right)} + \frac{1}{y - 1}\right)\right)}\right)\right) \]
          6. Step-by-step derivation
            1. *-lowering-*.f64N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \left(-1 \cdot \frac{y}{x \cdot \left(y - 1\right)} + \frac{1}{y - 1}\right)\right)\right)\right) \]
            2. +-commutativeN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \left(\frac{1}{y - 1} + -1 \cdot \frac{y}{x \cdot \left(y - 1\right)}\right)\right)\right)\right) \]
            3. +-lowering-+.f64N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\left(\frac{1}{y - 1}\right), \left(-1 \cdot \frac{y}{x \cdot \left(y - 1\right)}\right)\right)\right)\right)\right) \]
            4. /-lowering-/.f64N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \left(y - 1\right)\right), \left(-1 \cdot \frac{y}{x \cdot \left(y - 1\right)}\right)\right)\right)\right)\right) \]
            5. sub-negN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \left(y + \left(\mathsf{neg}\left(1\right)\right)\right)\right), \left(-1 \cdot \frac{y}{x \cdot \left(y - 1\right)}\right)\right)\right)\right)\right) \]
            6. metadata-evalN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \left(y + -1\right)\right), \left(-1 \cdot \frac{y}{x \cdot \left(y - 1\right)}\right)\right)\right)\right)\right) \]
            7. +-lowering-+.f64N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{+.f64}\left(y, -1\right)\right), \left(-1 \cdot \frac{y}{x \cdot \left(y - 1\right)}\right)\right)\right)\right)\right) \]
            8. associate-*r/N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{+.f64}\left(y, -1\right)\right), \left(\frac{-1 \cdot y}{x \cdot \left(y - 1\right)}\right)\right)\right)\right)\right) \]
            9. *-commutativeN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{+.f64}\left(y, -1\right)\right), \left(\frac{-1 \cdot y}{\left(y - 1\right) \cdot x}\right)\right)\right)\right)\right) \]
            10. associate-/r*N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{+.f64}\left(y, -1\right)\right), \left(\frac{\frac{-1 \cdot y}{y - 1}}{x}\right)\right)\right)\right)\right) \]
            11. associate-*r/N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{+.f64}\left(y, -1\right)\right), \left(\frac{-1 \cdot \frac{y}{y - 1}}{x}\right)\right)\right)\right)\right) \]
            12. /-lowering-/.f64N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{+.f64}\left(y, -1\right)\right), \mathsf{/.f64}\left(\left(-1 \cdot \frac{y}{y - 1}\right), x\right)\right)\right)\right)\right) \]
            13. mul-1-negN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{+.f64}\left(y, -1\right)\right), \mathsf{/.f64}\left(\left(\mathsf{neg}\left(\frac{y}{y - 1}\right)\right), x\right)\right)\right)\right)\right) \]
            14. distribute-neg-frac2N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{+.f64}\left(y, -1\right)\right), \mathsf{/.f64}\left(\left(\frac{y}{\mathsf{neg}\left(\left(y - 1\right)\right)}\right), x\right)\right)\right)\right)\right) \]
            15. /-lowering-/.f64N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{+.f64}\left(y, -1\right)\right), \mathsf{/.f64}\left(\mathsf{/.f64}\left(y, \left(\mathsf{neg}\left(\left(y - 1\right)\right)\right)\right), x\right)\right)\right)\right)\right) \]
            16. sub-negN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{+.f64}\left(y, -1\right)\right), \mathsf{/.f64}\left(\mathsf{/.f64}\left(y, \left(\mathsf{neg}\left(\left(y + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right), x\right)\right)\right)\right)\right) \]
            17. metadata-evalN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{+.f64}\left(y, -1\right)\right), \mathsf{/.f64}\left(\mathsf{/.f64}\left(y, \left(\mathsf{neg}\left(\left(y + -1\right)\right)\right)\right), x\right)\right)\right)\right)\right) \]
            18. +-commutativeN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{+.f64}\left(y, -1\right)\right), \mathsf{/.f64}\left(\mathsf{/.f64}\left(y, \left(\mathsf{neg}\left(\left(-1 + y\right)\right)\right)\right), x\right)\right)\right)\right)\right) \]
            19. distribute-neg-inN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{+.f64}\left(y, -1\right)\right), \mathsf{/.f64}\left(\mathsf{/.f64}\left(y, \left(\left(\mathsf{neg}\left(-1\right)\right) + \left(\mathsf{neg}\left(y\right)\right)\right)\right), x\right)\right)\right)\right)\right) \]
            20. metadata-evalN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{+.f64}\left(y, -1\right)\right), \mathsf{/.f64}\left(\mathsf{/.f64}\left(y, \left(1 + \left(\mathsf{neg}\left(y\right)\right)\right)\right), x\right)\right)\right)\right)\right) \]
            21. rgt-mult-inverseN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{+.f64}\left(y, -1\right)\right), \mathsf{/.f64}\left(\mathsf{/.f64}\left(y, \left(y \cdot \frac{1}{y} + \left(\mathsf{neg}\left(y\right)\right)\right)\right), x\right)\right)\right)\right)\right) \]
            22. unsub-negN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{+.f64}\left(y, -1\right)\right), \mathsf{/.f64}\left(\mathsf{/.f64}\left(y, \left(y \cdot \frac{1}{y} - y\right)\right), x\right)\right)\right)\right)\right) \]
            23. rgt-mult-inverseN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{+.f64}\left(y, -1\right)\right), \mathsf{/.f64}\left(\mathsf{/.f64}\left(y, \left(1 - y\right)\right), x\right)\right)\right)\right)\right) \]
            24. --lowering--.f6499.9%

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{+.f64}\left(y, -1\right)\right), \mathsf{/.f64}\left(\mathsf{/.f64}\left(y, \mathsf{\_.f64}\left(1, y\right)\right), x\right)\right)\right)\right)\right) \]
          7. Simplified99.9%

            \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{x \cdot \left(\frac{1}{y + -1} + \frac{\frac{y}{1 - y}}{x}\right)}\right) \]
        7. Recombined 2 regimes into one program.
        8. Final simplification79.6%

          \[\leadsto \begin{array}{l} \mathbf{if}\;1 + \frac{x - y}{y + -1} \leq 5 \cdot 10^{-7}:\\ \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \mathsf{log1p}\left(x \cdot \left(\frac{1}{y + -1} + \frac{\frac{y}{1 - y}}{x}\right)\right)\\ \end{array} \]
        9. Add Preprocessing

        Alternative 4: 81.5% accurate, 0.9× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x - y}{y + -1}\\ \mathbf{if}\;1 + t\_0 \leq 5 \cdot 10^{-7}:\\ \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \mathsf{log1p}\left(t\_0\right)\\ \end{array} \end{array} \]
        (FPCore (x y)
         :precision binary64
         (let* ((t_0 (/ (- x y) (+ y -1.0))))
           (if (<= (+ 1.0 t_0) 5e-7) (- 1.0 (log (/ x y))) (- 1.0 (log1p t_0)))))
        double code(double x, double y) {
        	double t_0 = (x - y) / (y + -1.0);
        	double tmp;
        	if ((1.0 + t_0) <= 5e-7) {
        		tmp = 1.0 - log((x / y));
        	} else {
        		tmp = 1.0 - log1p(t_0);
        	}
        	return tmp;
        }
        
        public static double code(double x, double y) {
        	double t_0 = (x - y) / (y + -1.0);
        	double tmp;
        	if ((1.0 + t_0) <= 5e-7) {
        		tmp = 1.0 - Math.log((x / y));
        	} else {
        		tmp = 1.0 - Math.log1p(t_0);
        	}
        	return tmp;
        }
        
        def code(x, y):
        	t_0 = (x - y) / (y + -1.0)
        	tmp = 0
        	if (1.0 + t_0) <= 5e-7:
        		tmp = 1.0 - math.log((x / y))
        	else:
        		tmp = 1.0 - math.log1p(t_0)
        	return tmp
        
        function code(x, y)
        	t_0 = Float64(Float64(x - y) / Float64(y + -1.0))
        	tmp = 0.0
        	if (Float64(1.0 + t_0) <= 5e-7)
        		tmp = Float64(1.0 - log(Float64(x / y)));
        	else
        		tmp = Float64(1.0 - log1p(t_0));
        	end
        	return tmp
        end
        
        code[x_, y_] := Block[{t$95$0 = N[(N[(x - y), $MachinePrecision] / N[(y + -1.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(1.0 + t$95$0), $MachinePrecision], 5e-7], N[(1.0 - N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Log[1 + t$95$0], $MachinePrecision]), $MachinePrecision]]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        t_0 := \frac{x - y}{y + -1}\\
        \mathbf{if}\;1 + t\_0 \leq 5 \cdot 10^{-7}:\\
        \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\
        
        \mathbf{else}:\\
        \;\;\;\;1 - \mathsf{log1p}\left(t\_0\right)\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if (-.f64 #s(literal 1 binary64) (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y))) < 4.99999999999999977e-7

          1. Initial program 5.4%

            \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
          2. Step-by-step derivation
            1. --lowering--.f64N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 - \frac{x - y}{1 - y}\right)}\right) \]
            2. sub-negN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
            3. log1p-defineN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \left(\mathsf{log1p}\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
            4. log1p-lowering-log1p.f64N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
            5. distribute-neg-frac2N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
            6. /-lowering-/.f64N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
            7. --lowering--.f64N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
            8. neg-sub0N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(0 - \left(1 - y\right)\right)\right)\right)\right) \]
            9. associate--r-N/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(0 - 1\right) + y\right)\right)\right)\right) \]
            10. metadata-evalN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
            11. +-commutativeN/A

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
            12. +-lowering-+.f645.4%

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
          3. Simplified5.4%

            \[\leadsto \color{blue}{1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
          4. Add Preprocessing
          5. Taylor expanded in y around inf

            \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \color{blue}{y}\right)\right)\right) \]
          6. Step-by-step derivation
            1. Simplified5.4%

              \[\leadsto 1 - \mathsf{log1p}\left(\frac{x - y}{\color{blue}{y}}\right) \]
            2. Step-by-step derivation
              1. --lowering--.f64N/A

                \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 + \frac{x - y}{y}\right)}\right) \]
              2. log-lowering-log.f64N/A

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

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x - y}{y} + 1\right)\right)\right) \]
              4. div-subN/A

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

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

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x}{y} - \left(1 - 1\right)\right)\right)\right) \]
              7. metadata-evalN/A

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x}{y} - 0\right)\right)\right) \]
              8. --lowering--.f64N/A

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{\_.f64}\left(\left(\frac{x}{y}\right), 0\right)\right)\right) \]
              9. /-lowering-/.f6432.5%

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{\_.f64}\left(\mathsf{/.f64}\left(x, y\right), 0\right)\right)\right) \]
            3. Applied egg-rr32.5%

              \[\leadsto \color{blue}{1 - \log \left(\frac{x}{y} - 0\right)} \]

            if 4.99999999999999977e-7 < (-.f64 #s(literal 1 binary64) (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y)))

            1. Initial program 99.9%

              \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
            2. Step-by-step derivation
              1. --lowering--.f64N/A

                \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 - \frac{x - y}{1 - y}\right)}\right) \]
              2. sub-negN/A

                \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
              3. log1p-defineN/A

                \[\leadsto \mathsf{\_.f64}\left(1, \left(\mathsf{log1p}\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
              4. log1p-lowering-log1p.f64N/A

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
              5. distribute-neg-frac2N/A

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
              6. /-lowering-/.f64N/A

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
              7. --lowering--.f64N/A

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
              8. neg-sub0N/A

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(0 - \left(1 - y\right)\right)\right)\right)\right) \]
              9. associate--r-N/A

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(0 - 1\right) + y\right)\right)\right)\right) \]
              10. metadata-evalN/A

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
              11. +-commutativeN/A

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
              12. +-lowering-+.f6499.9%

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
            3. Simplified99.9%

              \[\leadsto \color{blue}{1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
            4. Add Preprocessing
          7. Recombined 2 regimes into one program.
          8. Final simplification79.6%

            \[\leadsto \begin{array}{l} \mathbf{if}\;1 + \frac{x - y}{y + -1} \leq 5 \cdot 10^{-7}:\\ \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)\\ \end{array} \]
          9. Add Preprocessing

          Alternative 5: 79.8% accurate, 1.0× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} t_0 := 1 - \log \left(\frac{x}{y}\right)\\ \mathbf{if}\;y \leq -280000:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y \leq 1:\\ \;\;\;\;1 - \mathsf{log1p}\left(0 - x\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
          (FPCore (x y)
           :precision binary64
           (let* ((t_0 (- 1.0 (log (/ x y)))))
             (if (<= y -280000.0) t_0 (if (<= y 1.0) (- 1.0 (log1p (- 0.0 x))) t_0))))
          double code(double x, double y) {
          	double t_0 = 1.0 - log((x / y));
          	double tmp;
          	if (y <= -280000.0) {
          		tmp = t_0;
          	} else if (y <= 1.0) {
          		tmp = 1.0 - log1p((0.0 - x));
          	} else {
          		tmp = t_0;
          	}
          	return tmp;
          }
          
          public static double code(double x, double y) {
          	double t_0 = 1.0 - Math.log((x / y));
          	double tmp;
          	if (y <= -280000.0) {
          		tmp = t_0;
          	} else if (y <= 1.0) {
          		tmp = 1.0 - Math.log1p((0.0 - x));
          	} else {
          		tmp = t_0;
          	}
          	return tmp;
          }
          
          def code(x, y):
          	t_0 = 1.0 - math.log((x / y))
          	tmp = 0
          	if y <= -280000.0:
          		tmp = t_0
          	elif y <= 1.0:
          		tmp = 1.0 - math.log1p((0.0 - x))
          	else:
          		tmp = t_0
          	return tmp
          
          function code(x, y)
          	t_0 = Float64(1.0 - log(Float64(x / y)))
          	tmp = 0.0
          	if (y <= -280000.0)
          		tmp = t_0;
          	elseif (y <= 1.0)
          		tmp = Float64(1.0 - log1p(Float64(0.0 - x)));
          	else
          		tmp = t_0;
          	end
          	return tmp
          end
          
          code[x_, y_] := Block[{t$95$0 = N[(1.0 - N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[y, -280000.0], t$95$0, If[LessEqual[y, 1.0], N[(1.0 - N[Log[1 + N[(0.0 - x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], t$95$0]]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          t_0 := 1 - \log \left(\frac{x}{y}\right)\\
          \mathbf{if}\;y \leq -280000:\\
          \;\;\;\;t\_0\\
          
          \mathbf{elif}\;y \leq 1:\\
          \;\;\;\;1 - \mathsf{log1p}\left(0 - x\right)\\
          
          \mathbf{else}:\\
          \;\;\;\;t\_0\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if y < -2.8e5 or 1 < y

            1. Initial program 24.9%

              \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
            2. Step-by-step derivation
              1. --lowering--.f64N/A

                \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 - \frac{x - y}{1 - y}\right)}\right) \]
              2. sub-negN/A

                \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
              3. log1p-defineN/A

                \[\leadsto \mathsf{\_.f64}\left(1, \left(\mathsf{log1p}\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
              4. log1p-lowering-log1p.f64N/A

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
              5. distribute-neg-frac2N/A

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
              6. /-lowering-/.f64N/A

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
              7. --lowering--.f64N/A

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
              8. neg-sub0N/A

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(0 - \left(1 - y\right)\right)\right)\right)\right) \]
              9. associate--r-N/A

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(0 - 1\right) + y\right)\right)\right)\right) \]
              10. metadata-evalN/A

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
              11. +-commutativeN/A

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
              12. +-lowering-+.f6424.9%

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
            3. Simplified24.9%

              \[\leadsto \color{blue}{1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
            4. Add Preprocessing
            5. Taylor expanded in y around inf

              \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \color{blue}{y}\right)\right)\right) \]
            6. Step-by-step derivation
              1. Simplified23.8%

                \[\leadsto 1 - \mathsf{log1p}\left(\frac{x - y}{\color{blue}{y}}\right) \]
              2. Step-by-step derivation
                1. --lowering--.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 + \frac{x - y}{y}\right)}\right) \]
                2. log-lowering-log.f64N/A

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

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x - y}{y} + 1\right)\right)\right) \]
                4. div-subN/A

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

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

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x}{y} - \left(1 - 1\right)\right)\right)\right) \]
                7. metadata-evalN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x}{y} - 0\right)\right)\right) \]
                8. --lowering--.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{\_.f64}\left(\left(\frac{x}{y}\right), 0\right)\right)\right) \]
                9. /-lowering-/.f6445.3%

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{\_.f64}\left(\mathsf{/.f64}\left(x, y\right), 0\right)\right)\right) \]
              3. Applied egg-rr45.3%

                \[\leadsto \color{blue}{1 - \log \left(\frac{x}{y} - 0\right)} \]

              if -2.8e5 < y < 1

              1. Initial program 99.9%

                \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
              2. Step-by-step derivation
                1. --lowering--.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 - \frac{x - y}{1 - y}\right)}\right) \]
                2. sub-negN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                3. log1p-defineN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \left(\mathsf{log1p}\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                4. log1p-lowering-log1p.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                5. distribute-neg-frac2N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
                6. /-lowering-/.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
                7. --lowering--.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
                8. neg-sub0N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(0 - \left(1 - y\right)\right)\right)\right)\right) \]
                9. associate--r-N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(0 - 1\right) + y\right)\right)\right)\right) \]
                10. metadata-evalN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
                11. +-commutativeN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
                12. +-lowering-+.f6499.9%

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
              3. Simplified99.9%

                \[\leadsto \color{blue}{1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
              4. Add Preprocessing
              5. Taylor expanded in y around 0

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\color{blue}{\left(-1 \cdot x\right)}\right)\right) \]
              6. Step-by-step derivation
                1. mul-1-negN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right) \]
                2. neg-sub0N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(0 - x\right)\right)\right) \]
                3. --lowering--.f6498.1%

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{\_.f64}\left(0, x\right)\right)\right) \]
              7. Simplified98.1%

                \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{0 - x}\right) \]
            7. Recombined 2 regimes into one program.
            8. Final simplification78.1%

              \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -280000:\\ \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\ \mathbf{elif}\;y \leq 1:\\ \;\;\;\;1 - \mathsf{log1p}\left(0 - x\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\ \end{array} \]
            9. Add Preprocessing

            Alternative 6: 72.8% accurate, 1.0× speedup?

            \[\begin{array}{l} \\ \begin{array}{l} t_0 := 1 - \mathsf{log1p}\left(\frac{x}{y}\right)\\ \mathbf{if}\;y \leq -240000:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y \leq 1:\\ \;\;\;\;1 - \mathsf{log1p}\left(0 - x\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
            (FPCore (x y)
             :precision binary64
             (let* ((t_0 (- 1.0 (log1p (/ x y)))))
               (if (<= y -240000.0) t_0 (if (<= y 1.0) (- 1.0 (log1p (- 0.0 x))) t_0))))
            double code(double x, double y) {
            	double t_0 = 1.0 - log1p((x / y));
            	double tmp;
            	if (y <= -240000.0) {
            		tmp = t_0;
            	} else if (y <= 1.0) {
            		tmp = 1.0 - log1p((0.0 - x));
            	} else {
            		tmp = t_0;
            	}
            	return tmp;
            }
            
            public static double code(double x, double y) {
            	double t_0 = 1.0 - Math.log1p((x / y));
            	double tmp;
            	if (y <= -240000.0) {
            		tmp = t_0;
            	} else if (y <= 1.0) {
            		tmp = 1.0 - Math.log1p((0.0 - x));
            	} else {
            		tmp = t_0;
            	}
            	return tmp;
            }
            
            def code(x, y):
            	t_0 = 1.0 - math.log1p((x / y))
            	tmp = 0
            	if y <= -240000.0:
            		tmp = t_0
            	elif y <= 1.0:
            		tmp = 1.0 - math.log1p((0.0 - x))
            	else:
            		tmp = t_0
            	return tmp
            
            function code(x, y)
            	t_0 = Float64(1.0 - log1p(Float64(x / y)))
            	tmp = 0.0
            	if (y <= -240000.0)
            		tmp = t_0;
            	elseif (y <= 1.0)
            		tmp = Float64(1.0 - log1p(Float64(0.0 - x)));
            	else
            		tmp = t_0;
            	end
            	return tmp
            end
            
            code[x_, y_] := Block[{t$95$0 = N[(1.0 - N[Log[1 + N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[y, -240000.0], t$95$0, If[LessEqual[y, 1.0], N[(1.0 - N[Log[1 + N[(0.0 - x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], t$95$0]]]
            
            \begin{array}{l}
            
            \\
            \begin{array}{l}
            t_0 := 1 - \mathsf{log1p}\left(\frac{x}{y}\right)\\
            \mathbf{if}\;y \leq -240000:\\
            \;\;\;\;t\_0\\
            
            \mathbf{elif}\;y \leq 1:\\
            \;\;\;\;1 - \mathsf{log1p}\left(0 - x\right)\\
            
            \mathbf{else}:\\
            \;\;\;\;t\_0\\
            
            
            \end{array}
            \end{array}
            
            Derivation
            1. Split input into 2 regimes
            2. if y < -2.4e5 or 1 < y

              1. Initial program 24.9%

                \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
              2. Step-by-step derivation
                1. --lowering--.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 - \frac{x - y}{1 - y}\right)}\right) \]
                2. sub-negN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                3. log1p-defineN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \left(\mathsf{log1p}\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                4. log1p-lowering-log1p.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                5. distribute-neg-frac2N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
                6. /-lowering-/.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
                7. --lowering--.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
                8. neg-sub0N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(0 - \left(1 - y\right)\right)\right)\right)\right) \]
                9. associate--r-N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(0 - 1\right) + y\right)\right)\right)\right) \]
                10. metadata-evalN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
                11. +-commutativeN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
                12. +-lowering-+.f6424.9%

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
              3. Simplified24.9%

                \[\leadsto \color{blue}{1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
              4. Add Preprocessing
              5. Taylor expanded in x around inf

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\color{blue}{\left(\frac{x}{y - 1}\right)}\right)\right) \]
              6. Step-by-step derivation
                1. /-lowering-/.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(x, \left(y - 1\right)\right)\right)\right) \]
                2. sub-negN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(x, \left(y + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
                3. metadata-evalN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(x, \left(y + -1\right)\right)\right)\right) \]
                4. +-lowering-+.f6431.1%

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(x, \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
              7. Simplified31.1%

                \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{\frac{x}{y + -1}}\right) \]
              8. Taylor expanded in y around inf

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\color{blue}{\left(\frac{x}{y}\right)}\right)\right) \]
              9. Step-by-step derivation
                1. /-lowering-/.f6430.0%

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(x, y\right)\right)\right) \]
              10. Simplified30.0%

                \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{\frac{x}{y}}\right) \]

              if -2.4e5 < y < 1

              1. Initial program 99.9%

                \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
              2. Step-by-step derivation
                1. --lowering--.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 - \frac{x - y}{1 - y}\right)}\right) \]
                2. sub-negN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                3. log1p-defineN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \left(\mathsf{log1p}\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                4. log1p-lowering-log1p.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                5. distribute-neg-frac2N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
                6. /-lowering-/.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
                7. --lowering--.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
                8. neg-sub0N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(0 - \left(1 - y\right)\right)\right)\right)\right) \]
                9. associate--r-N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(0 - 1\right) + y\right)\right)\right)\right) \]
                10. metadata-evalN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
                11. +-commutativeN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
                12. +-lowering-+.f6499.9%

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
              3. Simplified99.9%

                \[\leadsto \color{blue}{1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
              4. Add Preprocessing
              5. Taylor expanded in y around 0

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\color{blue}{\left(-1 \cdot x\right)}\right)\right) \]
              6. Step-by-step derivation
                1. mul-1-negN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right) \]
                2. neg-sub0N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(0 - x\right)\right)\right) \]
                3. --lowering--.f6498.1%

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{\_.f64}\left(0, x\right)\right)\right) \]
              7. Simplified98.1%

                \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{0 - x}\right) \]
            3. Recombined 2 regimes into one program.
            4. Add Preprocessing

            Alternative 7: 77.8% accurate, 1.0× speedup?

            \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq 5 \cdot 10^{+14}:\\ \;\;\;\;1 - \mathsf{log1p}\left(\frac{x}{y + -1}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\ \end{array} \end{array} \]
            (FPCore (x y)
             :precision binary64
             (if (<= y 5e+14) (- 1.0 (log1p (/ x (+ y -1.0)))) (- 1.0 (log (/ x y)))))
            double code(double x, double y) {
            	double tmp;
            	if (y <= 5e+14) {
            		tmp = 1.0 - log1p((x / (y + -1.0)));
            	} else {
            		tmp = 1.0 - log((x / y));
            	}
            	return tmp;
            }
            
            public static double code(double x, double y) {
            	double tmp;
            	if (y <= 5e+14) {
            		tmp = 1.0 - Math.log1p((x / (y + -1.0)));
            	} else {
            		tmp = 1.0 - Math.log((x / y));
            	}
            	return tmp;
            }
            
            def code(x, y):
            	tmp = 0
            	if y <= 5e+14:
            		tmp = 1.0 - math.log1p((x / (y + -1.0)))
            	else:
            		tmp = 1.0 - math.log((x / y))
            	return tmp
            
            function code(x, y)
            	tmp = 0.0
            	if (y <= 5e+14)
            		tmp = Float64(1.0 - log1p(Float64(x / Float64(y + -1.0))));
            	else
            		tmp = Float64(1.0 - log(Float64(x / y)));
            	end
            	return tmp
            end
            
            code[x_, y_] := If[LessEqual[y, 5e+14], N[(1.0 - N[Log[1 + N[(x / N[(y + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
            
            \begin{array}{l}
            
            \\
            \begin{array}{l}
            \mathbf{if}\;y \leq 5 \cdot 10^{+14}:\\
            \;\;\;\;1 - \mathsf{log1p}\left(\frac{x}{y + -1}\right)\\
            
            \mathbf{else}:\\
            \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\
            
            
            \end{array}
            \end{array}
            
            Derivation
            1. Split input into 2 regimes
            2. if y < 5e14

              1. Initial program 74.3%

                \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
              2. Step-by-step derivation
                1. --lowering--.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 - \frac{x - y}{1 - y}\right)}\right) \]
                2. sub-negN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                3. log1p-defineN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \left(\mathsf{log1p}\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                4. log1p-lowering-log1p.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                5. distribute-neg-frac2N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
                6. /-lowering-/.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
                7. --lowering--.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
                8. neg-sub0N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(0 - \left(1 - y\right)\right)\right)\right)\right) \]
                9. associate--r-N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(0 - 1\right) + y\right)\right)\right)\right) \]
                10. metadata-evalN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
                11. +-commutativeN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
                12. +-lowering-+.f6474.3%

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
              3. Simplified74.3%

                \[\leadsto \color{blue}{1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
              4. Add Preprocessing
              5. Taylor expanded in x around inf

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\color{blue}{\left(\frac{x}{y - 1}\right)}\right)\right) \]
              6. Step-by-step derivation
                1. /-lowering-/.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(x, \left(y - 1\right)\right)\right)\right) \]
                2. sub-negN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(x, \left(y + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
                3. metadata-evalN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(x, \left(y + -1\right)\right)\right)\right) \]
                4. +-lowering-+.f6475.7%

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(x, \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
              7. Simplified75.7%

                \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{\frac{x}{y + -1}}\right) \]

              if 5e14 < y

              1. Initial program 36.3%

                \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
              2. Step-by-step derivation
                1. --lowering--.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 - \frac{x - y}{1 - y}\right)}\right) \]
                2. sub-negN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                3. log1p-defineN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \left(\mathsf{log1p}\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                4. log1p-lowering-log1p.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                5. distribute-neg-frac2N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
                6. /-lowering-/.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
                7. --lowering--.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
                8. neg-sub0N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(0 - \left(1 - y\right)\right)\right)\right)\right) \]
                9. associate--r-N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(0 - 1\right) + y\right)\right)\right)\right) \]
                10. metadata-evalN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
                11. +-commutativeN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
                12. +-lowering-+.f6436.3%

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
              3. Simplified36.3%

                \[\leadsto \color{blue}{1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
              4. Add Preprocessing
              5. Taylor expanded in y around inf

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \color{blue}{y}\right)\right)\right) \]
              6. Step-by-step derivation
                1. Simplified36.3%

                  \[\leadsto 1 - \mathsf{log1p}\left(\frac{x - y}{\color{blue}{y}}\right) \]
                2. Step-by-step derivation
                  1. --lowering--.f64N/A

                    \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 + \frac{x - y}{y}\right)}\right) \]
                  2. log-lowering-log.f64N/A

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

                    \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x - y}{y} + 1\right)\right)\right) \]
                  4. div-subN/A

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

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

                    \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x}{y} - \left(1 - 1\right)\right)\right)\right) \]
                  7. metadata-evalN/A

                    \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x}{y} - 0\right)\right)\right) \]
                  8. --lowering--.f64N/A

                    \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{\_.f64}\left(\left(\frac{x}{y}\right), 0\right)\right)\right) \]
                  9. /-lowering-/.f64100.0%

                    \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{\_.f64}\left(\mathsf{/.f64}\left(x, y\right), 0\right)\right)\right) \]
                3. Applied egg-rr100.0%

                  \[\leadsto \color{blue}{1 - \log \left(\frac{x}{y} - 0\right)} \]
              7. Recombined 2 regimes into one program.
              8. Final simplification77.5%

                \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 5 \cdot 10^{+14}:\\ \;\;\;\;1 - \mathsf{log1p}\left(\frac{x}{y + -1}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\ \end{array} \]
              9. Add Preprocessing

              Alternative 8: 63.7% accurate, 1.1× speedup?

              \[\begin{array}{l} \\ 1 - \mathsf{log1p}\left(0 - x\right) \end{array} \]
              (FPCore (x y) :precision binary64 (- 1.0 (log1p (- 0.0 x))))
              double code(double x, double y) {
              	return 1.0 - log1p((0.0 - x));
              }
              
              public static double code(double x, double y) {
              	return 1.0 - Math.log1p((0.0 - x));
              }
              
              def code(x, y):
              	return 1.0 - math.log1p((0.0 - x))
              
              function code(x, y)
              	return Float64(1.0 - log1p(Float64(0.0 - x)))
              end
              
              code[x_, y_] := N[(1.0 - N[Log[1 + N[(0.0 - x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
              
              \begin{array}{l}
              
              \\
              1 - \mathsf{log1p}\left(0 - x\right)
              \end{array}
              
              Derivation
              1. Initial program 71.4%

                \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
              2. Step-by-step derivation
                1. --lowering--.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 - \frac{x - y}{1 - y}\right)}\right) \]
                2. sub-negN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                3. log1p-defineN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \left(\mathsf{log1p}\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                4. log1p-lowering-log1p.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                5. distribute-neg-frac2N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
                6. /-lowering-/.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
                7. --lowering--.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
                8. neg-sub0N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(0 - \left(1 - y\right)\right)\right)\right)\right) \]
                9. associate--r-N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(0 - 1\right) + y\right)\right)\right)\right) \]
                10. metadata-evalN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
                11. +-commutativeN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
                12. +-lowering-+.f6471.5%

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
              3. Simplified71.5%

                \[\leadsto \color{blue}{1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
              4. Add Preprocessing
              5. Taylor expanded in y around 0

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\color{blue}{\left(-1 \cdot x\right)}\right)\right) \]
              6. Step-by-step derivation
                1. mul-1-negN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right) \]
                2. neg-sub0N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(0 - x\right)\right)\right) \]
                3. --lowering--.f6464.9%

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{\_.f64}\left(0, x\right)\right)\right) \]
              7. Simplified64.9%

                \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{0 - x}\right) \]
              8. Add Preprocessing

              Alternative 9: 45.3% accurate, 15.9× speedup?

              \[\begin{array}{l} \\ 1 + \frac{x}{1 - y} \end{array} \]
              (FPCore (x y) :precision binary64 (+ 1.0 (/ x (- 1.0 y))))
              double code(double x, double y) {
              	return 1.0 + (x / (1.0 - y));
              }
              
              real(8) function code(x, y)
                  real(8), intent (in) :: x
                  real(8), intent (in) :: y
                  code = 1.0d0 + (x / (1.0d0 - y))
              end function
              
              public static double code(double x, double y) {
              	return 1.0 + (x / (1.0 - y));
              }
              
              def code(x, y):
              	return 1.0 + (x / (1.0 - y))
              
              function code(x, y)
              	return Float64(1.0 + Float64(x / Float64(1.0 - y)))
              end
              
              function tmp = code(x, y)
              	tmp = 1.0 + (x / (1.0 - y));
              end
              
              code[x_, y_] := N[(1.0 + N[(x / N[(1.0 - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
              
              \begin{array}{l}
              
              \\
              1 + \frac{x}{1 - y}
              \end{array}
              
              Derivation
              1. Initial program 71.4%

                \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
              2. Step-by-step derivation
                1. --lowering--.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 - \frac{x - y}{1 - y}\right)}\right) \]
                2. sub-negN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                3. log1p-defineN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \left(\mathsf{log1p}\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                4. log1p-lowering-log1p.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                5. distribute-neg-frac2N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
                6. /-lowering-/.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
                7. --lowering--.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
                8. neg-sub0N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(0 - \left(1 - y\right)\right)\right)\right)\right) \]
                9. associate--r-N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(0 - 1\right) + y\right)\right)\right)\right) \]
                10. metadata-evalN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
                11. +-commutativeN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
                12. +-lowering-+.f6471.5%

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
              3. Simplified71.5%

                \[\leadsto \color{blue}{1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
              4. Add Preprocessing
              5. Taylor expanded in x around inf

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\color{blue}{\left(\frac{x}{y - 1}\right)}\right)\right) \]
              6. Step-by-step derivation
                1. /-lowering-/.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(x, \left(y - 1\right)\right)\right)\right) \]
                2. sub-negN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(x, \left(y + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
                3. metadata-evalN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(x, \left(y + -1\right)\right)\right)\right) \]
                4. +-lowering-+.f6473.2%

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(x, \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
              7. Simplified73.2%

                \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{\frac{x}{y + -1}}\right) \]
              8. Taylor expanded in x around 0

                \[\leadsto \color{blue}{1 + -1 \cdot \frac{x}{y - 1}} \]
              9. Step-by-step derivation
                1. mul-1-negN/A

                  \[\leadsto 1 + \left(\mathsf{neg}\left(\frac{x}{y - 1}\right)\right) \]
                2. unsub-negN/A

                  \[\leadsto 1 - \color{blue}{\frac{x}{y - 1}} \]
                3. --lowering--.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\left(\frac{x}{y - 1}\right)}\right) \]
                4. /-lowering-/.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(x, \color{blue}{\left(y - 1\right)}\right)\right) \]
                5. sub-negN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(x, \left(y + \color{blue}{\left(\mathsf{neg}\left(1\right)\right)}\right)\right)\right) \]
                6. metadata-evalN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(x, \left(y + -1\right)\right)\right) \]
                7. +-lowering-+.f6444.2%

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(y, \color{blue}{-1}\right)\right)\right) \]
              10. Simplified44.2%

                \[\leadsto \color{blue}{1 - \frac{x}{y + -1}} \]
              11. Final simplification44.2%

                \[\leadsto 1 + \frac{x}{1 - y} \]
              12. Add Preprocessing

              Alternative 10: 43.7% accurate, 111.0× speedup?

              \[\begin{array}{l} \\ 1 \end{array} \]
              (FPCore (x y) :precision binary64 1.0)
              double code(double x, double y) {
              	return 1.0;
              }
              
              real(8) function code(x, y)
                  real(8), intent (in) :: x
                  real(8), intent (in) :: y
                  code = 1.0d0
              end function
              
              public static double code(double x, double y) {
              	return 1.0;
              }
              
              def code(x, y):
              	return 1.0
              
              function code(x, y)
              	return 1.0
              end
              
              function tmp = code(x, y)
              	tmp = 1.0;
              end
              
              code[x_, y_] := 1.0
              
              \begin{array}{l}
              
              \\
              1
              \end{array}
              
              Derivation
              1. Initial program 71.4%

                \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
              2. Step-by-step derivation
                1. --lowering--.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 - \frac{x - y}{1 - y}\right)}\right) \]
                2. sub-negN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                3. log1p-defineN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \left(\mathsf{log1p}\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                4. log1p-lowering-log1p.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
                5. distribute-neg-frac2N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
                6. /-lowering-/.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
                7. --lowering--.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
                8. neg-sub0N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(0 - \left(1 - y\right)\right)\right)\right)\right) \]
                9. associate--r-N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(0 - 1\right) + y\right)\right)\right)\right) \]
                10. metadata-evalN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(-1 + y\right)\right)\right)\right) \]
                11. +-commutativeN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
                12. +-lowering-+.f6471.5%

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
              3. Simplified71.5%

                \[\leadsto \color{blue}{1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
              4. Add Preprocessing
              5. Taylor expanded in x around inf

                \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\color{blue}{\left(\frac{x}{y - 1}\right)}\right)\right) \]
              6. Step-by-step derivation
                1. /-lowering-/.f64N/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(x, \left(y - 1\right)\right)\right)\right) \]
                2. sub-negN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(x, \left(y + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
                3. metadata-evalN/A

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(x, \left(y + -1\right)\right)\right)\right) \]
                4. +-lowering-+.f6473.2%

                  \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(x, \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
              7. Simplified73.2%

                \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{\frac{x}{y + -1}}\right) \]
              8. Taylor expanded in x around 0

                \[\leadsto \color{blue}{1} \]
              9. Step-by-step derivation
                1. Simplified42.8%

                  \[\leadsto \color{blue}{1} \]
                2. Add Preprocessing

                Developer Target 1: 99.8% accurate, 0.5× speedup?

                \[\begin{array}{l} \\ \begin{array}{l} t_0 := 1 - \log \left(\frac{x}{y \cdot y} - \left(\frac{1}{y} - \frac{x}{y}\right)\right)\\ \mathbf{if}\;y < -81284752.61947241:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y < 3.0094271212461764 \cdot 10^{+25}:\\ \;\;\;\;\log \left(\frac{e^{1}}{1 - \frac{x - y}{1 - y}}\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
                (FPCore (x y)
                 :precision binary64
                 (let* ((t_0 (- 1.0 (log (- (/ x (* y y)) (- (/ 1.0 y) (/ x y)))))))
                   (if (< y -81284752.61947241)
                     t_0
                     (if (< y 3.0094271212461764e+25)
                       (log (/ (exp 1.0) (- 1.0 (/ (- x y) (- 1.0 y)))))
                       t_0))))
                double code(double x, double y) {
                	double t_0 = 1.0 - log(((x / (y * y)) - ((1.0 / y) - (x / y))));
                	double tmp;
                	if (y < -81284752.61947241) {
                		tmp = t_0;
                	} else if (y < 3.0094271212461764e+25) {
                		tmp = log((exp(1.0) / (1.0 - ((x - y) / (1.0 - y)))));
                	} else {
                		tmp = t_0;
                	}
                	return tmp;
                }
                
                real(8) function code(x, y)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    real(8) :: t_0
                    real(8) :: tmp
                    t_0 = 1.0d0 - log(((x / (y * y)) - ((1.0d0 / y) - (x / y))))
                    if (y < (-81284752.61947241d0)) then
                        tmp = t_0
                    else if (y < 3.0094271212461764d+25) then
                        tmp = log((exp(1.0d0) / (1.0d0 - ((x - y) / (1.0d0 - y)))))
                    else
                        tmp = t_0
                    end if
                    code = tmp
                end function
                
                public static double code(double x, double y) {
                	double t_0 = 1.0 - Math.log(((x / (y * y)) - ((1.0 / y) - (x / y))));
                	double tmp;
                	if (y < -81284752.61947241) {
                		tmp = t_0;
                	} else if (y < 3.0094271212461764e+25) {
                		tmp = Math.log((Math.exp(1.0) / (1.0 - ((x - y) / (1.0 - y)))));
                	} else {
                		tmp = t_0;
                	}
                	return tmp;
                }
                
                def code(x, y):
                	t_0 = 1.0 - math.log(((x / (y * y)) - ((1.0 / y) - (x / y))))
                	tmp = 0
                	if y < -81284752.61947241:
                		tmp = t_0
                	elif y < 3.0094271212461764e+25:
                		tmp = math.log((math.exp(1.0) / (1.0 - ((x - y) / (1.0 - y)))))
                	else:
                		tmp = t_0
                	return tmp
                
                function code(x, y)
                	t_0 = Float64(1.0 - log(Float64(Float64(x / Float64(y * y)) - Float64(Float64(1.0 / y) - Float64(x / y)))))
                	tmp = 0.0
                	if (y < -81284752.61947241)
                		tmp = t_0;
                	elseif (y < 3.0094271212461764e+25)
                		tmp = log(Float64(exp(1.0) / Float64(1.0 - Float64(Float64(x - y) / Float64(1.0 - y)))));
                	else
                		tmp = t_0;
                	end
                	return tmp
                end
                
                function tmp_2 = code(x, y)
                	t_0 = 1.0 - log(((x / (y * y)) - ((1.0 / y) - (x / y))));
                	tmp = 0.0;
                	if (y < -81284752.61947241)
                		tmp = t_0;
                	elseif (y < 3.0094271212461764e+25)
                		tmp = log((exp(1.0) / (1.0 - ((x - y) / (1.0 - y)))));
                	else
                		tmp = t_0;
                	end
                	tmp_2 = tmp;
                end
                
                code[x_, y_] := Block[{t$95$0 = N[(1.0 - N[Log[N[(N[(x / N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(N[(1.0 / y), $MachinePrecision] - N[(x / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[Less[y, -81284752.61947241], t$95$0, If[Less[y, 3.0094271212461764e+25], N[Log[N[(N[Exp[1.0], $MachinePrecision] / N[(1.0 - N[(N[(x - y), $MachinePrecision] / N[(1.0 - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], t$95$0]]]
                
                \begin{array}{l}
                
                \\
                \begin{array}{l}
                t_0 := 1 - \log \left(\frac{x}{y \cdot y} - \left(\frac{1}{y} - \frac{x}{y}\right)\right)\\
                \mathbf{if}\;y < -81284752.61947241:\\
                \;\;\;\;t\_0\\
                
                \mathbf{elif}\;y < 3.0094271212461764 \cdot 10^{+25}:\\
                \;\;\;\;\log \left(\frac{e^{1}}{1 - \frac{x - y}{1 - y}}\right)\\
                
                \mathbf{else}:\\
                \;\;\;\;t\_0\\
                
                
                \end{array}
                \end{array}
                

                Reproduce

                ?
                herbie shell --seed 2024160 
                (FPCore (x y)
                  :name "Numeric.SpecFunctions:invIncompleteGamma from math-functions-0.1.5.2, B"
                  :precision binary64
                
                  :alt
                  (! :herbie-platform default (if (< y -8128475261947241/100000000) (- 1 (log (- (/ x (* y y)) (- (/ 1 y) (/ x y))))) (if (< y 30094271212461764000000000) (log (/ (exp 1) (- 1 (/ (- x y) (- 1 y))))) (- 1 (log (- (/ x (* y y)) (- (/ 1 y) (/ x y))))))))
                
                  (- 1.0 (log (- 1.0 (/ (- x y) (- 1.0 y))))))