Numeric.SpecFunctions.Extra:bd0 from math-functions-0.1.5.2

Percentage Accurate: 77.3% → 99.4%
Time: 12.0s
Alternatives: 13
Speedup: 0.5×

Specification

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

\\
x \cdot \log \left(\frac{x}{y}\right) - z
\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 13 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: 77.3% accurate, 1.0× speedup?

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

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

Alternative 1: 99.4% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \log \left(-y\right)\\ t_1 := \log \left(-x\right)\\ \mathbf{if}\;y \leq -4 \cdot 10^{-310}:\\ \;\;\;\;\frac{{t\_1}^{3} - {t\_0}^{3}}{\left(t\_0 \cdot t\_1 + {t\_0}^{2}\right) + {t\_1}^{2}} \cdot x - z\\ \mathbf{else}:\\ \;\;\;\;\left(\log x - \log y\right) \cdot x - z\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (let* ((t_0 (log (- y))) (t_1 (log (- x))))
   (if (<= y -4e-310)
     (-
      (*
       (/
        (- (pow t_1 3.0) (pow t_0 3.0))
        (+ (+ (* t_0 t_1) (pow t_0 2.0)) (pow t_1 2.0)))
       x)
      z)
     (- (* (- (log x) (log y)) x) z))))
double code(double x, double y, double z) {
	double t_0 = log(-y);
	double t_1 = log(-x);
	double tmp;
	if (y <= -4e-310) {
		tmp = (((pow(t_1, 3.0) - pow(t_0, 3.0)) / (((t_0 * t_1) + pow(t_0, 2.0)) + pow(t_1, 2.0))) * x) - z;
	} else {
		tmp = ((log(x) - log(y)) * x) - z;
	}
	return tmp;
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = log(-y)
    t_1 = log(-x)
    if (y <= (-4d-310)) then
        tmp = ((((t_1 ** 3.0d0) - (t_0 ** 3.0d0)) / (((t_0 * t_1) + (t_0 ** 2.0d0)) + (t_1 ** 2.0d0))) * x) - z
    else
        tmp = ((log(x) - log(y)) * x) - z
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double t_0 = Math.log(-y);
	double t_1 = Math.log(-x);
	double tmp;
	if (y <= -4e-310) {
		tmp = (((Math.pow(t_1, 3.0) - Math.pow(t_0, 3.0)) / (((t_0 * t_1) + Math.pow(t_0, 2.0)) + Math.pow(t_1, 2.0))) * x) - z;
	} else {
		tmp = ((Math.log(x) - Math.log(y)) * x) - z;
	}
	return tmp;
}
def code(x, y, z):
	t_0 = math.log(-y)
	t_1 = math.log(-x)
	tmp = 0
	if y <= -4e-310:
		tmp = (((math.pow(t_1, 3.0) - math.pow(t_0, 3.0)) / (((t_0 * t_1) + math.pow(t_0, 2.0)) + math.pow(t_1, 2.0))) * x) - z
	else:
		tmp = ((math.log(x) - math.log(y)) * x) - z
	return tmp
function code(x, y, z)
	t_0 = log(Float64(-y))
	t_1 = log(Float64(-x))
	tmp = 0.0
	if (y <= -4e-310)
		tmp = Float64(Float64(Float64(Float64((t_1 ^ 3.0) - (t_0 ^ 3.0)) / Float64(Float64(Float64(t_0 * t_1) + (t_0 ^ 2.0)) + (t_1 ^ 2.0))) * x) - z);
	else
		tmp = Float64(Float64(Float64(log(x) - log(y)) * x) - z);
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	t_0 = log(-y);
	t_1 = log(-x);
	tmp = 0.0;
	if (y <= -4e-310)
		tmp = ((((t_1 ^ 3.0) - (t_0 ^ 3.0)) / (((t_0 * t_1) + (t_0 ^ 2.0)) + (t_1 ^ 2.0))) * x) - z;
	else
		tmp = ((log(x) - log(y)) * x) - z;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := Block[{t$95$0 = N[Log[(-y)], $MachinePrecision]}, Block[{t$95$1 = N[Log[(-x)], $MachinePrecision]}, If[LessEqual[y, -4e-310], N[(N[(N[(N[(N[Power[t$95$1, 3.0], $MachinePrecision] - N[Power[t$95$0, 3.0], $MachinePrecision]), $MachinePrecision] / N[(N[(N[(t$95$0 * t$95$1), $MachinePrecision] + N[Power[t$95$0, 2.0], $MachinePrecision]), $MachinePrecision] + N[Power[t$95$1, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision] - z), $MachinePrecision], N[(N[(N[(N[Log[x], $MachinePrecision] - N[Log[y], $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision] - z), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \log \left(-y\right)\\
t_1 := \log \left(-x\right)\\
\mathbf{if}\;y \leq -4 \cdot 10^{-310}:\\
\;\;\;\;\frac{{t\_1}^{3} - {t\_0}^{3}}{\left(t\_0 \cdot t\_1 + {t\_0}^{2}\right) + {t\_1}^{2}} \cdot x - z\\

\mathbf{else}:\\
\;\;\;\;\left(\log x - \log y\right) \cdot x - z\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -3.999999999999988e-310

    1. Initial program 76.9%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-log.f64N/A

        \[\leadsto x \cdot \color{blue}{\log \left(\frac{x}{y}\right)} - z \]
      2. lift-/.f64N/A

        \[\leadsto x \cdot \log \color{blue}{\left(\frac{x}{y}\right)} - z \]
      3. frac-2negN/A

        \[\leadsto x \cdot \log \color{blue}{\left(\frac{\mathsf{neg}\left(x\right)}{\mathsf{neg}\left(y\right)}\right)} - z \]
      4. log-divN/A

        \[\leadsto x \cdot \color{blue}{\left(\log \left(\mathsf{neg}\left(x\right)\right) - \log \left(\mathsf{neg}\left(y\right)\right)\right)} - z \]
      5. flip3--N/A

        \[\leadsto x \cdot \color{blue}{\frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{3} - {\log \left(\mathsf{neg}\left(y\right)\right)}^{3}}{\log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(x\right)\right) + \left(\log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right) + \log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)\right)}} - z \]
      6. lower-/.f64N/A

        \[\leadsto x \cdot \color{blue}{\frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{3} - {\log \left(\mathsf{neg}\left(y\right)\right)}^{3}}{\log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(x\right)\right) + \left(\log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right) + \log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)\right)}} - z \]
      7. lower--.f64N/A

        \[\leadsto x \cdot \frac{\color{blue}{{\log \left(\mathsf{neg}\left(x\right)\right)}^{3} - {\log \left(\mathsf{neg}\left(y\right)\right)}^{3}}}{\log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(x\right)\right) + \left(\log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right) + \log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)\right)} - z \]
      8. lower-pow.f64N/A

        \[\leadsto x \cdot \frac{\color{blue}{{\log \left(\mathsf{neg}\left(x\right)\right)}^{3}} - {\log \left(\mathsf{neg}\left(y\right)\right)}^{3}}{\log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(x\right)\right) + \left(\log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right) + \log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)\right)} - z \]
      9. lower-log.f64N/A

        \[\leadsto x \cdot \frac{{\color{blue}{\log \left(\mathsf{neg}\left(x\right)\right)}}^{3} - {\log \left(\mathsf{neg}\left(y\right)\right)}^{3}}{\log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(x\right)\right) + \left(\log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right) + \log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)\right)} - z \]
      10. lower-neg.f64N/A

        \[\leadsto x \cdot \frac{{\log \color{blue}{\left(\mathsf{neg}\left(x\right)\right)}}^{3} - {\log \left(\mathsf{neg}\left(y\right)\right)}^{3}}{\log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(x\right)\right) + \left(\log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right) + \log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)\right)} - z \]
      11. lower-pow.f64N/A

        \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{3} - \color{blue}{{\log \left(\mathsf{neg}\left(y\right)\right)}^{3}}}{\log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(x\right)\right) + \left(\log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right) + \log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)\right)} - z \]
      12. lower-log.f64N/A

        \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{3} - {\color{blue}{\log \left(\mathsf{neg}\left(y\right)\right)}}^{3}}{\log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(x\right)\right) + \left(\log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right) + \log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)\right)} - z \]
      13. lower-neg.f64N/A

        \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{3} - {\log \color{blue}{\left(\mathsf{neg}\left(y\right)\right)}}^{3}}{\log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(x\right)\right) + \left(\log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right) + \log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)\right)} - z \]
      14. lower-+.f64N/A

        \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{3} - {\log \left(\mathsf{neg}\left(y\right)\right)}^{3}}{\color{blue}{\log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(x\right)\right) + \left(\log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right) + \log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)\right)}} - z \]
    4. Applied rewrites99.3%

      \[\leadsto x \cdot \color{blue}{\frac{{\log \left(-x\right)}^{3} - {\log \left(-y\right)}^{3}}{{\log \left(-x\right)}^{2} + \left({\log \left(-y\right)}^{2} + \log \left(-x\right) \cdot \log \left(-y\right)\right)}} - z \]

    if -3.999999999999988e-310 < y

    1. Initial program 73.3%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-log.f64N/A

        \[\leadsto x \cdot \color{blue}{\log \left(\frac{x}{y}\right)} - z \]
      2. lift-/.f64N/A

        \[\leadsto x \cdot \log \color{blue}{\left(\frac{x}{y}\right)} - z \]
      3. log-divN/A

        \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
      4. lower--.f64N/A

        \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
      5. lower-log.f64N/A

        \[\leadsto x \cdot \left(\color{blue}{\log x} - \log y\right) - z \]
      6. lower-log.f6499.6

        \[\leadsto x \cdot \left(\log x - \color{blue}{\log y}\right) - z \]
    4. Applied rewrites99.6%

      \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -4 \cdot 10^{-310}:\\ \;\;\;\;\frac{{\log \left(-x\right)}^{3} - {\log \left(-y\right)}^{3}}{\left(\log \left(-y\right) \cdot \log \left(-x\right) + {\log \left(-y\right)}^{2}\right) + {\log \left(-x\right)}^{2}} \cdot x - z\\ \mathbf{else}:\\ \;\;\;\;\left(\log x - \log y\right) \cdot x - z\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 95.8% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \log \left(-x\right)\\ t_1 := \log \left(\frac{-1}{y}\right) + t\_0\\ \mathbf{if}\;x \leq -4.8 \cdot 10^{+153}:\\ \;\;\;\;\frac{1}{\frac{\frac{z}{{t\_1}^{2} \cdot x} - \frac{-1}{t\_1}}{x}}\\ \mathbf{elif}\;x \leq -5 \cdot 10^{-310}:\\ \;\;\;\;\frac{{t\_0}^{2} - {\log \left(-y\right)}^{2}}{\log \left(x \cdot y\right)} \cdot x - z\\ \mathbf{else}:\\ \;\;\;\;\left(\log x - \log y\right) \cdot x - z\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (let* ((t_0 (log (- x))) (t_1 (+ (log (/ -1.0 y)) t_0)))
   (if (<= x -4.8e+153)
     (/ 1.0 (/ (- (/ z (* (pow t_1 2.0) x)) (/ -1.0 t_1)) x))
     (if (<= x -5e-310)
       (- (* (/ (- (pow t_0 2.0) (pow (log (- y)) 2.0)) (log (* x y))) x) z)
       (- (* (- (log x) (log y)) x) z)))))
double code(double x, double y, double z) {
	double t_0 = log(-x);
	double t_1 = log((-1.0 / y)) + t_0;
	double tmp;
	if (x <= -4.8e+153) {
		tmp = 1.0 / (((z / (pow(t_1, 2.0) * x)) - (-1.0 / t_1)) / x);
	} else if (x <= -5e-310) {
		tmp = (((pow(t_0, 2.0) - pow(log(-y), 2.0)) / log((x * y))) * x) - z;
	} else {
		tmp = ((log(x) - log(y)) * x) - z;
	}
	return tmp;
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = log(-x)
    t_1 = log(((-1.0d0) / y)) + t_0
    if (x <= (-4.8d+153)) then
        tmp = 1.0d0 / (((z / ((t_1 ** 2.0d0) * x)) - ((-1.0d0) / t_1)) / x)
    else if (x <= (-5d-310)) then
        tmp = ((((t_0 ** 2.0d0) - (log(-y) ** 2.0d0)) / log((x * y))) * x) - z
    else
        tmp = ((log(x) - log(y)) * x) - z
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double t_0 = Math.log(-x);
	double t_1 = Math.log((-1.0 / y)) + t_0;
	double tmp;
	if (x <= -4.8e+153) {
		tmp = 1.0 / (((z / (Math.pow(t_1, 2.0) * x)) - (-1.0 / t_1)) / x);
	} else if (x <= -5e-310) {
		tmp = (((Math.pow(t_0, 2.0) - Math.pow(Math.log(-y), 2.0)) / Math.log((x * y))) * x) - z;
	} else {
		tmp = ((Math.log(x) - Math.log(y)) * x) - z;
	}
	return tmp;
}
def code(x, y, z):
	t_0 = math.log(-x)
	t_1 = math.log((-1.0 / y)) + t_0
	tmp = 0
	if x <= -4.8e+153:
		tmp = 1.0 / (((z / (math.pow(t_1, 2.0) * x)) - (-1.0 / t_1)) / x)
	elif x <= -5e-310:
		tmp = (((math.pow(t_0, 2.0) - math.pow(math.log(-y), 2.0)) / math.log((x * y))) * x) - z
	else:
		tmp = ((math.log(x) - math.log(y)) * x) - z
	return tmp
function code(x, y, z)
	t_0 = log(Float64(-x))
	t_1 = Float64(log(Float64(-1.0 / y)) + t_0)
	tmp = 0.0
	if (x <= -4.8e+153)
		tmp = Float64(1.0 / Float64(Float64(Float64(z / Float64((t_1 ^ 2.0) * x)) - Float64(-1.0 / t_1)) / x));
	elseif (x <= -5e-310)
		tmp = Float64(Float64(Float64(Float64((t_0 ^ 2.0) - (log(Float64(-y)) ^ 2.0)) / log(Float64(x * y))) * x) - z);
	else
		tmp = Float64(Float64(Float64(log(x) - log(y)) * x) - z);
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	t_0 = log(-x);
	t_1 = log((-1.0 / y)) + t_0;
	tmp = 0.0;
	if (x <= -4.8e+153)
		tmp = 1.0 / (((z / ((t_1 ^ 2.0) * x)) - (-1.0 / t_1)) / x);
	elseif (x <= -5e-310)
		tmp = ((((t_0 ^ 2.0) - (log(-y) ^ 2.0)) / log((x * y))) * x) - z;
	else
		tmp = ((log(x) - log(y)) * x) - z;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := Block[{t$95$0 = N[Log[(-x)], $MachinePrecision]}, Block[{t$95$1 = N[(N[Log[N[(-1.0 / y), $MachinePrecision]], $MachinePrecision] + t$95$0), $MachinePrecision]}, If[LessEqual[x, -4.8e+153], N[(1.0 / N[(N[(N[(z / N[(N[Power[t$95$1, 2.0], $MachinePrecision] * x), $MachinePrecision]), $MachinePrecision] - N[(-1.0 / t$95$1), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision], If[LessEqual[x, -5e-310], N[(N[(N[(N[(N[Power[t$95$0, 2.0], $MachinePrecision] - N[Power[N[Log[(-y)], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision] / N[Log[N[(x * y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision] - z), $MachinePrecision], N[(N[(N[(N[Log[x], $MachinePrecision] - N[Log[y], $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision] - z), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \log \left(-x\right)\\
t_1 := \log \left(\frac{-1}{y}\right) + t\_0\\
\mathbf{if}\;x \leq -4.8 \cdot 10^{+153}:\\
\;\;\;\;\frac{1}{\frac{\frac{z}{{t\_1}^{2} \cdot x} - \frac{-1}{t\_1}}{x}}\\

\mathbf{elif}\;x \leq -5 \cdot 10^{-310}:\\
\;\;\;\;\frac{{t\_0}^{2} - {\log \left(-y\right)}^{2}}{\log \left(x \cdot y\right)} \cdot x - z\\

\mathbf{else}:\\
\;\;\;\;\left(\log x - \log y\right) \cdot x - z\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -4.79999999999999985e153

    1. Initial program 71.4%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift--.f64N/A

        \[\leadsto \color{blue}{x \cdot \log \left(\frac{x}{y}\right) - z} \]
      2. flip--N/A

        \[\leadsto \color{blue}{\frac{\left(x \cdot \log \left(\frac{x}{y}\right)\right) \cdot \left(x \cdot \log \left(\frac{x}{y}\right)\right) - z \cdot z}{x \cdot \log \left(\frac{x}{y}\right) + z}} \]
      3. clear-numN/A

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

        \[\leadsto \color{blue}{\frac{1}{\frac{x \cdot \log \left(\frac{x}{y}\right) + z}{\left(x \cdot \log \left(\frac{x}{y}\right)\right) \cdot \left(x \cdot \log \left(\frac{x}{y}\right)\right) - z \cdot z}}} \]
      5. clear-numN/A

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{\frac{\left(x \cdot \log \left(\frac{x}{y}\right)\right) \cdot \left(x \cdot \log \left(\frac{x}{y}\right)\right) - z \cdot z}{x \cdot \log \left(\frac{x}{y}\right) + z}}}} \]
      6. flip--N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{x \cdot \log \left(\frac{x}{y}\right) - z}}} \]
      7. lift--.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{x \cdot \log \left(\frac{x}{y}\right) - z}}} \]
      8. lower-/.f6471.3

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{x \cdot \log \left(\frac{x}{y}\right) - z}}} \]
      9. lift--.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{x \cdot \log \left(\frac{x}{y}\right) - z}}} \]
      10. sub-negN/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{x \cdot \log \left(\frac{x}{y}\right) + \left(\mathsf{neg}\left(z\right)\right)}}} \]
      11. lift-*.f64N/A

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

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{\log \left(\frac{x}{y}\right) \cdot x} + \left(\mathsf{neg}\left(z\right)\right)}} \]
      13. lower-fma.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{\mathsf{fma}\left(\log \left(\frac{x}{y}\right), x, \mathsf{neg}\left(z\right)\right)}}} \]
      14. lower-neg.f6471.3

        \[\leadsto \frac{1}{\frac{1}{\mathsf{fma}\left(\log \left(\frac{x}{y}\right), x, \color{blue}{-z}\right)}} \]
    4. Applied rewrites71.3%

      \[\leadsto \color{blue}{\frac{1}{\frac{1}{\mathsf{fma}\left(\log \left(\frac{x}{y}\right), x, -z\right)}}} \]
    5. Taylor expanded in x around -inf

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

        \[\leadsto \frac{1}{\color{blue}{\frac{-1 \cdot \left(-1 \cdot \frac{z}{x \cdot {\left(\log \left(\frac{-1}{y}\right) + -1 \cdot \log \left(\frac{-1}{x}\right)\right)}^{2}} - \frac{1}{\log \left(\frac{-1}{y}\right) + -1 \cdot \log \left(\frac{-1}{x}\right)}\right)}{x}}} \]
    7. Applied rewrites98.9%

      \[\leadsto \frac{1}{\color{blue}{\frac{\frac{z}{{\left(\log \left(\frac{-1}{y}\right) - \left(-\log \left(-x\right)\right)\right)}^{2} \cdot x} + \frac{1}{\log \left(\frac{-1}{y}\right) - \left(-\log \left(-x\right)\right)}}{x}}} \]

    if -4.79999999999999985e153 < x < -4.999999999999985e-310

    1. Initial program 79.1%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-log.f64N/A

        \[\leadsto x \cdot \color{blue}{\log \left(\frac{x}{y}\right)} - z \]
      2. lift-/.f64N/A

        \[\leadsto x \cdot \log \color{blue}{\left(\frac{x}{y}\right)} - z \]
      3. frac-2negN/A

        \[\leadsto x \cdot \log \color{blue}{\left(\frac{\mathsf{neg}\left(x\right)}{\mathsf{neg}\left(y\right)}\right)} - z \]
      4. log-divN/A

        \[\leadsto x \cdot \color{blue}{\left(\log \left(\mathsf{neg}\left(x\right)\right) - \log \left(\mathsf{neg}\left(y\right)\right)\right)} - z \]
      5. flip--N/A

        \[\leadsto x \cdot \color{blue}{\frac{\log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(x\right)\right) - \log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)}} - z \]
      6. lower-/.f64N/A

        \[\leadsto x \cdot \color{blue}{\frac{\log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(x\right)\right) - \log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)}} - z \]
      7. lower--.f64N/A

        \[\leadsto x \cdot \frac{\color{blue}{\log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(x\right)\right) - \log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)}}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)} - z \]
      8. pow2N/A

        \[\leadsto x \cdot \frac{\color{blue}{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2}} - \log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)} - z \]
      9. lower-pow.f64N/A

        \[\leadsto x \cdot \frac{\color{blue}{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2}} - \log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)} - z \]
      10. lower-log.f64N/A

        \[\leadsto x \cdot \frac{{\color{blue}{\log \left(\mathsf{neg}\left(x\right)\right)}}^{2} - \log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)} - z \]
      11. lower-neg.f64N/A

        \[\leadsto x \cdot \frac{{\log \color{blue}{\left(\mathsf{neg}\left(x\right)\right)}}^{2} - \log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)} - z \]
      12. pow2N/A

        \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2} - \color{blue}{{\log \left(\mathsf{neg}\left(y\right)\right)}^{2}}}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)} - z \]
      13. lower-pow.f64N/A

        \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2} - \color{blue}{{\log \left(\mathsf{neg}\left(y\right)\right)}^{2}}}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)} - z \]
      14. lower-log.f64N/A

        \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2} - {\color{blue}{\log \left(\mathsf{neg}\left(y\right)\right)}}^{2}}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)} - z \]
      15. lower-neg.f64N/A

        \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2} - {\log \color{blue}{\left(\mathsf{neg}\left(y\right)\right)}}^{2}}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)} - z \]
      16. sum-logN/A

        \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2} - {\log \left(\mathsf{neg}\left(y\right)\right)}^{2}}{\color{blue}{\log \left(\left(\mathsf{neg}\left(x\right)\right) \cdot \left(\mathsf{neg}\left(y\right)\right)\right)}} - z \]
      17. lower-log.f64N/A

        \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2} - {\log \left(\mathsf{neg}\left(y\right)\right)}^{2}}{\color{blue}{\log \left(\left(\mathsf{neg}\left(x\right)\right) \cdot \left(\mathsf{neg}\left(y\right)\right)\right)}} - z \]
      18. lower-*.f64N/A

        \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2} - {\log \left(\mathsf{neg}\left(y\right)\right)}^{2}}{\log \color{blue}{\left(\left(\mathsf{neg}\left(x\right)\right) \cdot \left(\mathsf{neg}\left(y\right)\right)\right)}} - z \]
      19. lower-neg.f64N/A

        \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2} - {\log \left(\mathsf{neg}\left(y\right)\right)}^{2}}{\log \left(\color{blue}{\left(\mathsf{neg}\left(x\right)\right)} \cdot \left(\mathsf{neg}\left(y\right)\right)\right)} - z \]
      20. lower-neg.f6496.5

        \[\leadsto x \cdot \frac{{\log \left(-x\right)}^{2} - {\log \left(-y\right)}^{2}}{\log \left(\left(-x\right) \cdot \color{blue}{\left(-y\right)}\right)} - z \]
    4. Applied rewrites96.5%

      \[\leadsto x \cdot \color{blue}{\frac{{\log \left(-x\right)}^{2} - {\log \left(-y\right)}^{2}}{\log \left(\left(-x\right) \cdot \left(-y\right)\right)}} - z \]

    if -4.999999999999985e-310 < x

    1. Initial program 73.3%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-log.f64N/A

        \[\leadsto x \cdot \color{blue}{\log \left(\frac{x}{y}\right)} - z \]
      2. lift-/.f64N/A

        \[\leadsto x \cdot \log \color{blue}{\left(\frac{x}{y}\right)} - z \]
      3. log-divN/A

        \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
      4. lower--.f64N/A

        \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
      5. lower-log.f64N/A

        \[\leadsto x \cdot \left(\color{blue}{\log x} - \log y\right) - z \]
      6. lower-log.f6499.6

        \[\leadsto x \cdot \left(\log x - \color{blue}{\log y}\right) - z \]
    4. Applied rewrites99.6%

      \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
  3. Recombined 3 regimes into one program.
  4. Final simplification98.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -4.8 \cdot 10^{+153}:\\ \;\;\;\;\frac{1}{\frac{\frac{z}{{\left(\log \left(\frac{-1}{y}\right) + \log \left(-x\right)\right)}^{2} \cdot x} - \frac{-1}{\log \left(\frac{-1}{y}\right) + \log \left(-x\right)}}{x}}\\ \mathbf{elif}\;x \leq -5 \cdot 10^{-310}:\\ \;\;\;\;\frac{{\log \left(-x\right)}^{2} - {\log \left(-y\right)}^{2}}{\log \left(x \cdot y\right)} \cdot x - z\\ \mathbf{else}:\\ \;\;\;\;\left(\log x - \log y\right) \cdot x - z\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 95.8% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \log \left(-x\right)\\ t_1 := \log \left(-y\right)\\ \mathbf{if}\;x \leq -3.1 \cdot 10^{+153}:\\ \;\;\;\;\left(t\_0 - t\_1\right) \cdot x\\ \mathbf{elif}\;x \leq -5 \cdot 10^{-310}:\\ \;\;\;\;\frac{{t\_0}^{2} - {t\_1}^{2}}{\log \left(x \cdot y\right)} \cdot x - z\\ \mathbf{else}:\\ \;\;\;\;\left(\log x - \log y\right) \cdot x - z\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (let* ((t_0 (log (- x))) (t_1 (log (- y))))
   (if (<= x -3.1e+153)
     (* (- t_0 t_1) x)
     (if (<= x -5e-310)
       (- (* (/ (- (pow t_0 2.0) (pow t_1 2.0)) (log (* x y))) x) z)
       (- (* (- (log x) (log y)) x) z)))))
double code(double x, double y, double z) {
	double t_0 = log(-x);
	double t_1 = log(-y);
	double tmp;
	if (x <= -3.1e+153) {
		tmp = (t_0 - t_1) * x;
	} else if (x <= -5e-310) {
		tmp = (((pow(t_0, 2.0) - pow(t_1, 2.0)) / log((x * y))) * x) - z;
	} else {
		tmp = ((log(x) - log(y)) * x) - z;
	}
	return tmp;
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = log(-x)
    t_1 = log(-y)
    if (x <= (-3.1d+153)) then
        tmp = (t_0 - t_1) * x
    else if (x <= (-5d-310)) then
        tmp = ((((t_0 ** 2.0d0) - (t_1 ** 2.0d0)) / log((x * y))) * x) - z
    else
        tmp = ((log(x) - log(y)) * x) - z
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double t_0 = Math.log(-x);
	double t_1 = Math.log(-y);
	double tmp;
	if (x <= -3.1e+153) {
		tmp = (t_0 - t_1) * x;
	} else if (x <= -5e-310) {
		tmp = (((Math.pow(t_0, 2.0) - Math.pow(t_1, 2.0)) / Math.log((x * y))) * x) - z;
	} else {
		tmp = ((Math.log(x) - Math.log(y)) * x) - z;
	}
	return tmp;
}
def code(x, y, z):
	t_0 = math.log(-x)
	t_1 = math.log(-y)
	tmp = 0
	if x <= -3.1e+153:
		tmp = (t_0 - t_1) * x
	elif x <= -5e-310:
		tmp = (((math.pow(t_0, 2.0) - math.pow(t_1, 2.0)) / math.log((x * y))) * x) - z
	else:
		tmp = ((math.log(x) - math.log(y)) * x) - z
	return tmp
function code(x, y, z)
	t_0 = log(Float64(-x))
	t_1 = log(Float64(-y))
	tmp = 0.0
	if (x <= -3.1e+153)
		tmp = Float64(Float64(t_0 - t_1) * x);
	elseif (x <= -5e-310)
		tmp = Float64(Float64(Float64(Float64((t_0 ^ 2.0) - (t_1 ^ 2.0)) / log(Float64(x * y))) * x) - z);
	else
		tmp = Float64(Float64(Float64(log(x) - log(y)) * x) - z);
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	t_0 = log(-x);
	t_1 = log(-y);
	tmp = 0.0;
	if (x <= -3.1e+153)
		tmp = (t_0 - t_1) * x;
	elseif (x <= -5e-310)
		tmp = ((((t_0 ^ 2.0) - (t_1 ^ 2.0)) / log((x * y))) * x) - z;
	else
		tmp = ((log(x) - log(y)) * x) - z;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := Block[{t$95$0 = N[Log[(-x)], $MachinePrecision]}, Block[{t$95$1 = N[Log[(-y)], $MachinePrecision]}, If[LessEqual[x, -3.1e+153], N[(N[(t$95$0 - t$95$1), $MachinePrecision] * x), $MachinePrecision], If[LessEqual[x, -5e-310], N[(N[(N[(N[(N[Power[t$95$0, 2.0], $MachinePrecision] - N[Power[t$95$1, 2.0], $MachinePrecision]), $MachinePrecision] / N[Log[N[(x * y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision] - z), $MachinePrecision], N[(N[(N[(N[Log[x], $MachinePrecision] - N[Log[y], $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision] - z), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \log \left(-x\right)\\
t_1 := \log \left(-y\right)\\
\mathbf{if}\;x \leq -3.1 \cdot 10^{+153}:\\
\;\;\;\;\left(t\_0 - t\_1\right) \cdot x\\

\mathbf{elif}\;x \leq -5 \cdot 10^{-310}:\\
\;\;\;\;\frac{{t\_0}^{2} - {t\_1}^{2}}{\log \left(x \cdot y\right)} \cdot x - z\\

\mathbf{else}:\\
\;\;\;\;\left(\log x - \log y\right) \cdot x - z\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -3.1e153

    1. Initial program 71.4%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

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

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

        \[\leadsto \log \left(\frac{1}{y}\right) \cdot x + \color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{1}{x}\right)\right)\right)} \cdot x \]
      3. log-recN/A

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

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

        \[\leadsto \color{blue}{x \cdot \left(\log \left(\frac{1}{y}\right) + \log x\right)} \]
      6. +-commutativeN/A

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

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

        \[\leadsto \color{blue}{\left(\log x + \log \left(\frac{1}{y}\right)\right) \cdot x} \]
      9. log-recN/A

        \[\leadsto \left(\log x + \color{blue}{\left(\mathsf{neg}\left(\log y\right)\right)}\right) \cdot x \]
      10. unsub-negN/A

        \[\leadsto \color{blue}{\left(\log x - \log y\right)} \cdot x \]
      11. lower--.f64N/A

        \[\leadsto \color{blue}{\left(\log x - \log y\right)} \cdot x \]
      12. lower-log.f64N/A

        \[\leadsto \left(\color{blue}{\log x} - \log y\right) \cdot x \]
      13. lower-log.f640.0

        \[\leadsto \left(\log x - \color{blue}{\log y}\right) \cdot x \]
    5. Applied rewrites0.0%

      \[\leadsto \color{blue}{\left(\log x - \log y\right) \cdot x} \]
    6. Step-by-step derivation
      1. Applied rewrites98.8%

        \[\leadsto \left(\log \left(-x\right) - \log \left(-y\right)\right) \cdot x \]

      if -3.1e153 < x < -4.999999999999985e-310

      1. Initial program 79.1%

        \[x \cdot \log \left(\frac{x}{y}\right) - z \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift-log.f64N/A

          \[\leadsto x \cdot \color{blue}{\log \left(\frac{x}{y}\right)} - z \]
        2. lift-/.f64N/A

          \[\leadsto x \cdot \log \color{blue}{\left(\frac{x}{y}\right)} - z \]
        3. frac-2negN/A

          \[\leadsto x \cdot \log \color{blue}{\left(\frac{\mathsf{neg}\left(x\right)}{\mathsf{neg}\left(y\right)}\right)} - z \]
        4. log-divN/A

          \[\leadsto x \cdot \color{blue}{\left(\log \left(\mathsf{neg}\left(x\right)\right) - \log \left(\mathsf{neg}\left(y\right)\right)\right)} - z \]
        5. flip--N/A

          \[\leadsto x \cdot \color{blue}{\frac{\log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(x\right)\right) - \log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)}} - z \]
        6. lower-/.f64N/A

          \[\leadsto x \cdot \color{blue}{\frac{\log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(x\right)\right) - \log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)}} - z \]
        7. lower--.f64N/A

          \[\leadsto x \cdot \frac{\color{blue}{\log \left(\mathsf{neg}\left(x\right)\right) \cdot \log \left(\mathsf{neg}\left(x\right)\right) - \log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)}}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)} - z \]
        8. pow2N/A

          \[\leadsto x \cdot \frac{\color{blue}{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2}} - \log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)} - z \]
        9. lower-pow.f64N/A

          \[\leadsto x \cdot \frac{\color{blue}{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2}} - \log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)} - z \]
        10. lower-log.f64N/A

          \[\leadsto x \cdot \frac{{\color{blue}{\log \left(\mathsf{neg}\left(x\right)\right)}}^{2} - \log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)} - z \]
        11. lower-neg.f64N/A

          \[\leadsto x \cdot \frac{{\log \color{blue}{\left(\mathsf{neg}\left(x\right)\right)}}^{2} - \log \left(\mathsf{neg}\left(y\right)\right) \cdot \log \left(\mathsf{neg}\left(y\right)\right)}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)} - z \]
        12. pow2N/A

          \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2} - \color{blue}{{\log \left(\mathsf{neg}\left(y\right)\right)}^{2}}}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)} - z \]
        13. lower-pow.f64N/A

          \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2} - \color{blue}{{\log \left(\mathsf{neg}\left(y\right)\right)}^{2}}}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)} - z \]
        14. lower-log.f64N/A

          \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2} - {\color{blue}{\log \left(\mathsf{neg}\left(y\right)\right)}}^{2}}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)} - z \]
        15. lower-neg.f64N/A

          \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2} - {\log \color{blue}{\left(\mathsf{neg}\left(y\right)\right)}}^{2}}{\log \left(\mathsf{neg}\left(x\right)\right) + \log \left(\mathsf{neg}\left(y\right)\right)} - z \]
        16. sum-logN/A

          \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2} - {\log \left(\mathsf{neg}\left(y\right)\right)}^{2}}{\color{blue}{\log \left(\left(\mathsf{neg}\left(x\right)\right) \cdot \left(\mathsf{neg}\left(y\right)\right)\right)}} - z \]
        17. lower-log.f64N/A

          \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2} - {\log \left(\mathsf{neg}\left(y\right)\right)}^{2}}{\color{blue}{\log \left(\left(\mathsf{neg}\left(x\right)\right) \cdot \left(\mathsf{neg}\left(y\right)\right)\right)}} - z \]
        18. lower-*.f64N/A

          \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2} - {\log \left(\mathsf{neg}\left(y\right)\right)}^{2}}{\log \color{blue}{\left(\left(\mathsf{neg}\left(x\right)\right) \cdot \left(\mathsf{neg}\left(y\right)\right)\right)}} - z \]
        19. lower-neg.f64N/A

          \[\leadsto x \cdot \frac{{\log \left(\mathsf{neg}\left(x\right)\right)}^{2} - {\log \left(\mathsf{neg}\left(y\right)\right)}^{2}}{\log \left(\color{blue}{\left(\mathsf{neg}\left(x\right)\right)} \cdot \left(\mathsf{neg}\left(y\right)\right)\right)} - z \]
        20. lower-neg.f6496.5

          \[\leadsto x \cdot \frac{{\log \left(-x\right)}^{2} - {\log \left(-y\right)}^{2}}{\log \left(\left(-x\right) \cdot \color{blue}{\left(-y\right)}\right)} - z \]
      4. Applied rewrites96.5%

        \[\leadsto x \cdot \color{blue}{\frac{{\log \left(-x\right)}^{2} - {\log \left(-y\right)}^{2}}{\log \left(\left(-x\right) \cdot \left(-y\right)\right)}} - z \]

      if -4.999999999999985e-310 < x

      1. Initial program 73.3%

        \[x \cdot \log \left(\frac{x}{y}\right) - z \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift-log.f64N/A

          \[\leadsto x \cdot \color{blue}{\log \left(\frac{x}{y}\right)} - z \]
        2. lift-/.f64N/A

          \[\leadsto x \cdot \log \color{blue}{\left(\frac{x}{y}\right)} - z \]
        3. log-divN/A

          \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
        4. lower--.f64N/A

          \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
        5. lower-log.f64N/A

          \[\leadsto x \cdot \left(\color{blue}{\log x} - \log y\right) - z \]
        6. lower-log.f6499.6

          \[\leadsto x \cdot \left(\log x - \color{blue}{\log y}\right) - z \]
      4. Applied rewrites99.6%

        \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
    7. Recombined 3 regimes into one program.
    8. Final simplification98.4%

      \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -3.1 \cdot 10^{+153}:\\ \;\;\;\;\left(\log \left(-x\right) - \log \left(-y\right)\right) \cdot x\\ \mathbf{elif}\;x \leq -5 \cdot 10^{-310}:\\ \;\;\;\;\frac{{\log \left(-x\right)}^{2} - {\log \left(-y\right)}^{2}}{\log \left(x \cdot y\right)} \cdot x - z\\ \mathbf{else}:\\ \;\;\;\;\left(\log x - \log y\right) \cdot x - z\\ \end{array} \]
    9. Add Preprocessing

    Alternative 4: 87.3% accurate, 0.3× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := \log \left(\frac{x}{y}\right) \cdot x\\ \mathbf{if}\;t\_0 \leq -\infty:\\ \;\;\;\;-z\\ \mathbf{elif}\;t\_0 \leq 10^{+306}:\\ \;\;\;\;\log \left(\frac{\frac{-1}{y}}{\frac{-1}{x}}\right) \cdot x - z\\ \mathbf{else}:\\ \;\;\;\;\left(\log x - \log y\right) \cdot x\\ \end{array} \end{array} \]
    (FPCore (x y z)
     :precision binary64
     (let* ((t_0 (* (log (/ x y)) x)))
       (if (<= t_0 (- INFINITY))
         (- z)
         (if (<= t_0 1e+306)
           (- (* (log (/ (/ -1.0 y) (/ -1.0 x))) x) z)
           (* (- (log x) (log y)) x)))))
    double code(double x, double y, double z) {
    	double t_0 = log((x / y)) * x;
    	double tmp;
    	if (t_0 <= -((double) INFINITY)) {
    		tmp = -z;
    	} else if (t_0 <= 1e+306) {
    		tmp = (log(((-1.0 / y) / (-1.0 / x))) * x) - z;
    	} else {
    		tmp = (log(x) - log(y)) * x;
    	}
    	return tmp;
    }
    
    public static double code(double x, double y, double z) {
    	double t_0 = Math.log((x / y)) * x;
    	double tmp;
    	if (t_0 <= -Double.POSITIVE_INFINITY) {
    		tmp = -z;
    	} else if (t_0 <= 1e+306) {
    		tmp = (Math.log(((-1.0 / y) / (-1.0 / x))) * x) - z;
    	} else {
    		tmp = (Math.log(x) - Math.log(y)) * x;
    	}
    	return tmp;
    }
    
    def code(x, y, z):
    	t_0 = math.log((x / y)) * x
    	tmp = 0
    	if t_0 <= -math.inf:
    		tmp = -z
    	elif t_0 <= 1e+306:
    		tmp = (math.log(((-1.0 / y) / (-1.0 / x))) * x) - z
    	else:
    		tmp = (math.log(x) - math.log(y)) * x
    	return tmp
    
    function code(x, y, z)
    	t_0 = Float64(log(Float64(x / y)) * x)
    	tmp = 0.0
    	if (t_0 <= Float64(-Inf))
    		tmp = Float64(-z);
    	elseif (t_0 <= 1e+306)
    		tmp = Float64(Float64(log(Float64(Float64(-1.0 / y) / Float64(-1.0 / x))) * x) - z);
    	else
    		tmp = Float64(Float64(log(x) - log(y)) * x);
    	end
    	return tmp
    end
    
    function tmp_2 = code(x, y, z)
    	t_0 = log((x / y)) * x;
    	tmp = 0.0;
    	if (t_0 <= -Inf)
    		tmp = -z;
    	elseif (t_0 <= 1e+306)
    		tmp = (log(((-1.0 / y) / (-1.0 / x))) * x) - z;
    	else
    		tmp = (log(x) - log(y)) * x;
    	end
    	tmp_2 = tmp;
    end
    
    code[x_, y_, z_] := Block[{t$95$0 = N[(N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision] * x), $MachinePrecision]}, If[LessEqual[t$95$0, (-Infinity)], (-z), If[LessEqual[t$95$0, 1e+306], N[(N[(N[Log[N[(N[(-1.0 / y), $MachinePrecision] / N[(-1.0 / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * x), $MachinePrecision] - z), $MachinePrecision], N[(N[(N[Log[x], $MachinePrecision] - N[Log[y], $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision]]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := \log \left(\frac{x}{y}\right) \cdot x\\
    \mathbf{if}\;t\_0 \leq -\infty:\\
    \;\;\;\;-z\\
    
    \mathbf{elif}\;t\_0 \leq 10^{+306}:\\
    \;\;\;\;\log \left(\frac{\frac{-1}{y}}{\frac{-1}{x}}\right) \cdot x - z\\
    
    \mathbf{else}:\\
    \;\;\;\;\left(\log x - \log y\right) \cdot x\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if (*.f64 x (log.f64 (/.f64 x y))) < -inf.0

      1. Initial program 11.2%

        \[x \cdot \log \left(\frac{x}{y}\right) - z \]
      2. Add Preprocessing
      3. Taylor expanded in z around inf

        \[\leadsto \color{blue}{-1 \cdot z} \]
      4. Step-by-step derivation
        1. mul-1-negN/A

          \[\leadsto \color{blue}{\mathsf{neg}\left(z\right)} \]
        2. lower-neg.f6441.9

          \[\leadsto \color{blue}{-z} \]
      5. Applied rewrites41.9%

        \[\leadsto \color{blue}{-z} \]

      if -inf.0 < (*.f64 x (log.f64 (/.f64 x y))) < 1.00000000000000002e306

      1. Initial program 99.5%

        \[x \cdot \log \left(\frac{x}{y}\right) - z \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift-/.f64N/A

          \[\leadsto x \cdot \log \color{blue}{\left(\frac{x}{y}\right)} - z \]
        2. clear-numN/A

          \[\leadsto x \cdot \log \color{blue}{\left(\frac{1}{\frac{y}{x}}\right)} - z \]
        3. div-invN/A

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

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

          \[\leadsto x \cdot \log \color{blue}{\left(\frac{\frac{1}{y}}{\frac{1}{x}}\right)} - z \]
        6. lower-/.f64N/A

          \[\leadsto x \cdot \log \left(\frac{\color{blue}{\frac{1}{y}}}{\frac{1}{x}}\right) - z \]
        7. lower-/.f6499.6

          \[\leadsto x \cdot \log \left(\frac{\frac{1}{y}}{\color{blue}{\frac{1}{x}}}\right) - z \]
      4. Applied rewrites99.6%

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

      if 1.00000000000000002e306 < (*.f64 x (log.f64 (/.f64 x y)))

      1. Initial program 4.5%

        \[x \cdot \log \left(\frac{x}{y}\right) - z \]
      2. Add Preprocessing
      3. Taylor expanded in x around inf

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

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

          \[\leadsto \log \left(\frac{1}{y}\right) \cdot x + \color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{1}{x}\right)\right)\right)} \cdot x \]
        3. log-recN/A

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

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

          \[\leadsto \color{blue}{x \cdot \left(\log \left(\frac{1}{y}\right) + \log x\right)} \]
        6. +-commutativeN/A

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

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

          \[\leadsto \color{blue}{\left(\log x + \log \left(\frac{1}{y}\right)\right) \cdot x} \]
        9. log-recN/A

          \[\leadsto \left(\log x + \color{blue}{\left(\mathsf{neg}\left(\log y\right)\right)}\right) \cdot x \]
        10. unsub-negN/A

          \[\leadsto \color{blue}{\left(\log x - \log y\right)} \cdot x \]
        11. lower--.f64N/A

          \[\leadsto \color{blue}{\left(\log x - \log y\right)} \cdot x \]
        12. lower-log.f64N/A

          \[\leadsto \left(\color{blue}{\log x} - \log y\right) \cdot x \]
        13. lower-log.f6452.6

          \[\leadsto \left(\log x - \color{blue}{\log y}\right) \cdot x \]
      5. Applied rewrites52.6%

        \[\leadsto \color{blue}{\left(\log x - \log y\right) \cdot x} \]
    3. Recombined 3 regimes into one program.
    4. Final simplification85.8%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\log \left(\frac{x}{y}\right) \cdot x \leq -\infty:\\ \;\;\;\;-z\\ \mathbf{elif}\;\log \left(\frac{x}{y}\right) \cdot x \leq 10^{+306}:\\ \;\;\;\;\log \left(\frac{\frac{-1}{y}}{\frac{-1}{x}}\right) \cdot x - z\\ \mathbf{else}:\\ \;\;\;\;\left(\log x - \log y\right) \cdot x\\ \end{array} \]
    5. Add Preprocessing

    Alternative 5: 87.2% accurate, 0.3× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := \log \left(\frac{x}{y}\right) \cdot x\\ \mathbf{if}\;t\_0 \leq -\infty:\\ \;\;\;\;-z\\ \mathbf{elif}\;t\_0 \leq 10^{+306}:\\ \;\;\;\;\log \left(\frac{\frac{-1}{y}}{\frac{-1}{x}}\right) \cdot x - z\\ \mathbf{else}:\\ \;\;\;\;-z\\ \end{array} \end{array} \]
    (FPCore (x y z)
     :precision binary64
     (let* ((t_0 (* (log (/ x y)) x)))
       (if (<= t_0 (- INFINITY))
         (- z)
         (if (<= t_0 1e+306) (- (* (log (/ (/ -1.0 y) (/ -1.0 x))) x) z) (- z)))))
    double code(double x, double y, double z) {
    	double t_0 = log((x / y)) * x;
    	double tmp;
    	if (t_0 <= -((double) INFINITY)) {
    		tmp = -z;
    	} else if (t_0 <= 1e+306) {
    		tmp = (log(((-1.0 / y) / (-1.0 / x))) * x) - z;
    	} else {
    		tmp = -z;
    	}
    	return tmp;
    }
    
    public static double code(double x, double y, double z) {
    	double t_0 = Math.log((x / y)) * x;
    	double tmp;
    	if (t_0 <= -Double.POSITIVE_INFINITY) {
    		tmp = -z;
    	} else if (t_0 <= 1e+306) {
    		tmp = (Math.log(((-1.0 / y) / (-1.0 / x))) * x) - z;
    	} else {
    		tmp = -z;
    	}
    	return tmp;
    }
    
    def code(x, y, z):
    	t_0 = math.log((x / y)) * x
    	tmp = 0
    	if t_0 <= -math.inf:
    		tmp = -z
    	elif t_0 <= 1e+306:
    		tmp = (math.log(((-1.0 / y) / (-1.0 / x))) * x) - z
    	else:
    		tmp = -z
    	return tmp
    
    function code(x, y, z)
    	t_0 = Float64(log(Float64(x / y)) * x)
    	tmp = 0.0
    	if (t_0 <= Float64(-Inf))
    		tmp = Float64(-z);
    	elseif (t_0 <= 1e+306)
    		tmp = Float64(Float64(log(Float64(Float64(-1.0 / y) / Float64(-1.0 / x))) * x) - z);
    	else
    		tmp = Float64(-z);
    	end
    	return tmp
    end
    
    function tmp_2 = code(x, y, z)
    	t_0 = log((x / y)) * x;
    	tmp = 0.0;
    	if (t_0 <= -Inf)
    		tmp = -z;
    	elseif (t_0 <= 1e+306)
    		tmp = (log(((-1.0 / y) / (-1.0 / x))) * x) - z;
    	else
    		tmp = -z;
    	end
    	tmp_2 = tmp;
    end
    
    code[x_, y_, z_] := Block[{t$95$0 = N[(N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision] * x), $MachinePrecision]}, If[LessEqual[t$95$0, (-Infinity)], (-z), If[LessEqual[t$95$0, 1e+306], N[(N[(N[Log[N[(N[(-1.0 / y), $MachinePrecision] / N[(-1.0 / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * x), $MachinePrecision] - z), $MachinePrecision], (-z)]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := \log \left(\frac{x}{y}\right) \cdot x\\
    \mathbf{if}\;t\_0 \leq -\infty:\\
    \;\;\;\;-z\\
    
    \mathbf{elif}\;t\_0 \leq 10^{+306}:\\
    \;\;\;\;\log \left(\frac{\frac{-1}{y}}{\frac{-1}{x}}\right) \cdot x - z\\
    
    \mathbf{else}:\\
    \;\;\;\;-z\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (*.f64 x (log.f64 (/.f64 x y))) < -inf.0 or 1.00000000000000002e306 < (*.f64 x (log.f64 (/.f64 x y)))

      1. Initial program 7.5%

        \[x \cdot \log \left(\frac{x}{y}\right) - z \]
      2. Add Preprocessing
      3. Taylor expanded in z around inf

        \[\leadsto \color{blue}{-1 \cdot z} \]
      4. Step-by-step derivation
        1. mul-1-negN/A

          \[\leadsto \color{blue}{\mathsf{neg}\left(z\right)} \]
        2. lower-neg.f6440.4

          \[\leadsto \color{blue}{-z} \]
      5. Applied rewrites40.4%

        \[\leadsto \color{blue}{-z} \]

      if -inf.0 < (*.f64 x (log.f64 (/.f64 x y))) < 1.00000000000000002e306

      1. Initial program 99.5%

        \[x \cdot \log \left(\frac{x}{y}\right) - z \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift-/.f64N/A

          \[\leadsto x \cdot \log \color{blue}{\left(\frac{x}{y}\right)} - z \]
        2. clear-numN/A

          \[\leadsto x \cdot \log \color{blue}{\left(\frac{1}{\frac{y}{x}}\right)} - z \]
        3. div-invN/A

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

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

          \[\leadsto x \cdot \log \color{blue}{\left(\frac{\frac{1}{y}}{\frac{1}{x}}\right)} - z \]
        6. lower-/.f64N/A

          \[\leadsto x \cdot \log \left(\frac{\color{blue}{\frac{1}{y}}}{\frac{1}{x}}\right) - z \]
        7. lower-/.f6499.6

          \[\leadsto x \cdot \log \left(\frac{\frac{1}{y}}{\color{blue}{\frac{1}{x}}}\right) - z \]
      4. Applied rewrites99.6%

        \[\leadsto x \cdot \log \color{blue}{\left(\frac{\frac{1}{y}}{\frac{1}{x}}\right)} - z \]
    3. Recombined 2 regimes into one program.
    4. Final simplification83.8%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\log \left(\frac{x}{y}\right) \cdot x \leq -\infty:\\ \;\;\;\;-z\\ \mathbf{elif}\;\log \left(\frac{x}{y}\right) \cdot x \leq 10^{+306}:\\ \;\;\;\;\log \left(\frac{\frac{-1}{y}}{\frac{-1}{x}}\right) \cdot x - z\\ \mathbf{else}:\\ \;\;\;\;-z\\ \end{array} \]
    5. Add Preprocessing

    Alternative 6: 87.2% accurate, 0.3× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := \log \left(\frac{x}{y}\right) \cdot x\\ \mathbf{if}\;t\_0 \leq -\infty:\\ \;\;\;\;-z\\ \mathbf{elif}\;t\_0 \leq 10^{+306}:\\ \;\;\;\;t\_0 - z\\ \mathbf{else}:\\ \;\;\;\;-z\\ \end{array} \end{array} \]
    (FPCore (x y z)
     :precision binary64
     (let* ((t_0 (* (log (/ x y)) x)))
       (if (<= t_0 (- INFINITY)) (- z) (if (<= t_0 1e+306) (- t_0 z) (- z)))))
    double code(double x, double y, double z) {
    	double t_0 = log((x / y)) * x;
    	double tmp;
    	if (t_0 <= -((double) INFINITY)) {
    		tmp = -z;
    	} else if (t_0 <= 1e+306) {
    		tmp = t_0 - z;
    	} else {
    		tmp = -z;
    	}
    	return tmp;
    }
    
    public static double code(double x, double y, double z) {
    	double t_0 = Math.log((x / y)) * x;
    	double tmp;
    	if (t_0 <= -Double.POSITIVE_INFINITY) {
    		tmp = -z;
    	} else if (t_0 <= 1e+306) {
    		tmp = t_0 - z;
    	} else {
    		tmp = -z;
    	}
    	return tmp;
    }
    
    def code(x, y, z):
    	t_0 = math.log((x / y)) * x
    	tmp = 0
    	if t_0 <= -math.inf:
    		tmp = -z
    	elif t_0 <= 1e+306:
    		tmp = t_0 - z
    	else:
    		tmp = -z
    	return tmp
    
    function code(x, y, z)
    	t_0 = Float64(log(Float64(x / y)) * x)
    	tmp = 0.0
    	if (t_0 <= Float64(-Inf))
    		tmp = Float64(-z);
    	elseif (t_0 <= 1e+306)
    		tmp = Float64(t_0 - z);
    	else
    		tmp = Float64(-z);
    	end
    	return tmp
    end
    
    function tmp_2 = code(x, y, z)
    	t_0 = log((x / y)) * x;
    	tmp = 0.0;
    	if (t_0 <= -Inf)
    		tmp = -z;
    	elseif (t_0 <= 1e+306)
    		tmp = t_0 - z;
    	else
    		tmp = -z;
    	end
    	tmp_2 = tmp;
    end
    
    code[x_, y_, z_] := Block[{t$95$0 = N[(N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision] * x), $MachinePrecision]}, If[LessEqual[t$95$0, (-Infinity)], (-z), If[LessEqual[t$95$0, 1e+306], N[(t$95$0 - z), $MachinePrecision], (-z)]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := \log \left(\frac{x}{y}\right) \cdot x\\
    \mathbf{if}\;t\_0 \leq -\infty:\\
    \;\;\;\;-z\\
    
    \mathbf{elif}\;t\_0 \leq 10^{+306}:\\
    \;\;\;\;t\_0 - z\\
    
    \mathbf{else}:\\
    \;\;\;\;-z\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (*.f64 x (log.f64 (/.f64 x y))) < -inf.0 or 1.00000000000000002e306 < (*.f64 x (log.f64 (/.f64 x y)))

      1. Initial program 7.5%

        \[x \cdot \log \left(\frac{x}{y}\right) - z \]
      2. Add Preprocessing
      3. Taylor expanded in z around inf

        \[\leadsto \color{blue}{-1 \cdot z} \]
      4. Step-by-step derivation
        1. mul-1-negN/A

          \[\leadsto \color{blue}{\mathsf{neg}\left(z\right)} \]
        2. lower-neg.f6440.4

          \[\leadsto \color{blue}{-z} \]
      5. Applied rewrites40.4%

        \[\leadsto \color{blue}{-z} \]

      if -inf.0 < (*.f64 x (log.f64 (/.f64 x y))) < 1.00000000000000002e306

      1. Initial program 99.5%

        \[x \cdot \log \left(\frac{x}{y}\right) - z \]
      2. Add Preprocessing
    3. Recombined 2 regimes into one program.
    4. Final simplification83.8%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\log \left(\frac{x}{y}\right) \cdot x \leq -\infty:\\ \;\;\;\;-z\\ \mathbf{elif}\;\log \left(\frac{x}{y}\right) \cdot x \leq 10^{+306}:\\ \;\;\;\;\log \left(\frac{x}{y}\right) \cdot x - z\\ \mathbf{else}:\\ \;\;\;\;-z\\ \end{array} \]
    5. Add Preprocessing

    Alternative 7: 96.7% accurate, 0.5× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := \log \left(-x\right) - \log \left(-y\right)\\ \mathbf{if}\;x \leq -7.2 \cdot 10^{+153}:\\ \;\;\;\;t\_0 \cdot x\\ \mathbf{elif}\;x \leq -5 \cdot 10^{-310}:\\ \;\;\;\;\mathsf{fma}\left(t\_0, \frac{x}{z}, -1\right) \cdot z\\ \mathbf{else}:\\ \;\;\;\;\left(\log x - \log y\right) \cdot x - z\\ \end{array} \end{array} \]
    (FPCore (x y z)
     :precision binary64
     (let* ((t_0 (- (log (- x)) (log (- y)))))
       (if (<= x -7.2e+153)
         (* t_0 x)
         (if (<= x -5e-310)
           (* (fma t_0 (/ x z) -1.0) z)
           (- (* (- (log x) (log y)) x) z)))))
    double code(double x, double y, double z) {
    	double t_0 = log(-x) - log(-y);
    	double tmp;
    	if (x <= -7.2e+153) {
    		tmp = t_0 * x;
    	} else if (x <= -5e-310) {
    		tmp = fma(t_0, (x / z), -1.0) * z;
    	} else {
    		tmp = ((log(x) - log(y)) * x) - z;
    	}
    	return tmp;
    }
    
    function code(x, y, z)
    	t_0 = Float64(log(Float64(-x)) - log(Float64(-y)))
    	tmp = 0.0
    	if (x <= -7.2e+153)
    		tmp = Float64(t_0 * x);
    	elseif (x <= -5e-310)
    		tmp = Float64(fma(t_0, Float64(x / z), -1.0) * z);
    	else
    		tmp = Float64(Float64(Float64(log(x) - log(y)) * x) - z);
    	end
    	return tmp
    end
    
    code[x_, y_, z_] := Block[{t$95$0 = N[(N[Log[(-x)], $MachinePrecision] - N[Log[(-y)], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[x, -7.2e+153], N[(t$95$0 * x), $MachinePrecision], If[LessEqual[x, -5e-310], N[(N[(t$95$0 * N[(x / z), $MachinePrecision] + -1.0), $MachinePrecision] * z), $MachinePrecision], N[(N[(N[(N[Log[x], $MachinePrecision] - N[Log[y], $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision] - z), $MachinePrecision]]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := \log \left(-x\right) - \log \left(-y\right)\\
    \mathbf{if}\;x \leq -7.2 \cdot 10^{+153}:\\
    \;\;\;\;t\_0 \cdot x\\
    
    \mathbf{elif}\;x \leq -5 \cdot 10^{-310}:\\
    \;\;\;\;\mathsf{fma}\left(t\_0, \frac{x}{z}, -1\right) \cdot z\\
    
    \mathbf{else}:\\
    \;\;\;\;\left(\log x - \log y\right) \cdot x - z\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if x < -7.2000000000000001e153

      1. Initial program 71.4%

        \[x \cdot \log \left(\frac{x}{y}\right) - z \]
      2. Add Preprocessing
      3. Taylor expanded in x around inf

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

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

          \[\leadsto \log \left(\frac{1}{y}\right) \cdot x + \color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{1}{x}\right)\right)\right)} \cdot x \]
        3. log-recN/A

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

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

          \[\leadsto \color{blue}{x \cdot \left(\log \left(\frac{1}{y}\right) + \log x\right)} \]
        6. +-commutativeN/A

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

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

          \[\leadsto \color{blue}{\left(\log x + \log \left(\frac{1}{y}\right)\right) \cdot x} \]
        9. log-recN/A

          \[\leadsto \left(\log x + \color{blue}{\left(\mathsf{neg}\left(\log y\right)\right)}\right) \cdot x \]
        10. unsub-negN/A

          \[\leadsto \color{blue}{\left(\log x - \log y\right)} \cdot x \]
        11. lower--.f64N/A

          \[\leadsto \color{blue}{\left(\log x - \log y\right)} \cdot x \]
        12. lower-log.f64N/A

          \[\leadsto \left(\color{blue}{\log x} - \log y\right) \cdot x \]
        13. lower-log.f640.0

          \[\leadsto \left(\log x - \color{blue}{\log y}\right) \cdot x \]
      5. Applied rewrites0.0%

        \[\leadsto \color{blue}{\left(\log x - \log y\right) \cdot x} \]
      6. Step-by-step derivation
        1. Applied rewrites98.8%

          \[\leadsto \left(\log \left(-x\right) - \log \left(-y\right)\right) \cdot x \]

        if -7.2000000000000001e153 < x < -4.999999999999985e-310

        1. Initial program 79.1%

          \[x \cdot \log \left(\frac{x}{y}\right) - z \]
        2. Add Preprocessing
        3. Step-by-step derivation
          1. lift-/.f64N/A

            \[\leadsto x \cdot \log \color{blue}{\left(\frac{x}{y}\right)} - z \]
          2. clear-numN/A

            \[\leadsto x \cdot \log \color{blue}{\left(\frac{1}{\frac{y}{x}}\right)} - z \]
          3. div-invN/A

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

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

            \[\leadsto x \cdot \log \color{blue}{\left(\frac{\frac{1}{y}}{\frac{1}{x}}\right)} - z \]
          6. lower-/.f64N/A

            \[\leadsto x \cdot \log \left(\frac{\color{blue}{\frac{1}{y}}}{\frac{1}{x}}\right) - z \]
          7. lower-/.f6479.1

            \[\leadsto x \cdot \log \left(\frac{\frac{1}{y}}{\color{blue}{\frac{1}{x}}}\right) - z \]
        4. Applied rewrites79.1%

          \[\leadsto x \cdot \log \color{blue}{\left(\frac{\frac{1}{y}}{\frac{1}{x}}\right)} - z \]
        5. Taylor expanded in z around inf

          \[\leadsto \color{blue}{z \cdot \left(\frac{x \cdot \log \left(\frac{x}{y}\right)}{z} - 1\right)} \]
        6. Step-by-step derivation
          1. *-commutativeN/A

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

            \[\leadsto \color{blue}{\left(\frac{x \cdot \log \left(\frac{x}{y}\right)}{z} - 1\right) \cdot z} \]
          3. sub-negN/A

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

            \[\leadsto \left(\frac{\color{blue}{\log \left(\frac{x}{y}\right) \cdot x}}{z} + \left(\mathsf{neg}\left(1\right)\right)\right) \cdot z \]
          5. associate-/l*N/A

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

            \[\leadsto \left(\log \left(\frac{x}{y}\right) \cdot \frac{x}{z} + \color{blue}{-1}\right) \cdot z \]
          7. lower-fma.f64N/A

            \[\leadsto \color{blue}{\mathsf{fma}\left(\log \left(\frac{x}{y}\right), \frac{x}{z}, -1\right)} \cdot z \]
          8. lower-log.f64N/A

            \[\leadsto \mathsf{fma}\left(\color{blue}{\log \left(\frac{x}{y}\right)}, \frac{x}{z}, -1\right) \cdot z \]
          9. lower-/.f64N/A

            \[\leadsto \mathsf{fma}\left(\log \color{blue}{\left(\frac{x}{y}\right)}, \frac{x}{z}, -1\right) \cdot z \]
          10. lower-/.f6473.5

            \[\leadsto \mathsf{fma}\left(\log \left(\frac{x}{y}\right), \color{blue}{\frac{x}{z}}, -1\right) \cdot z \]
        7. Applied rewrites73.5%

          \[\leadsto \color{blue}{\mathsf{fma}\left(\log \left(\frac{x}{y}\right), \frac{x}{z}, -1\right) \cdot z} \]
        8. Step-by-step derivation
          1. Applied rewrites94.3%

            \[\leadsto \mathsf{fma}\left(\log \left(-x\right) - \log \left(-y\right), \frac{x}{z}, -1\right) \cdot z \]

          if -4.999999999999985e-310 < x

          1. Initial program 73.3%

            \[x \cdot \log \left(\frac{x}{y}\right) - z \]
          2. Add Preprocessing
          3. Step-by-step derivation
            1. lift-log.f64N/A

              \[\leadsto x \cdot \color{blue}{\log \left(\frac{x}{y}\right)} - z \]
            2. lift-/.f64N/A

              \[\leadsto x \cdot \log \color{blue}{\left(\frac{x}{y}\right)} - z \]
            3. log-divN/A

              \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
            4. lower--.f64N/A

              \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
            5. lower-log.f64N/A

              \[\leadsto x \cdot \left(\color{blue}{\log x} - \log y\right) - z \]
            6. lower-log.f6499.6

              \[\leadsto x \cdot \left(\log x - \color{blue}{\log y}\right) - z \]
          4. Applied rewrites99.6%

            \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
        9. Recombined 3 regimes into one program.
        10. Final simplification97.6%

          \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -7.2 \cdot 10^{+153}:\\ \;\;\;\;\left(\log \left(-x\right) - \log \left(-y\right)\right) \cdot x\\ \mathbf{elif}\;x \leq -5 \cdot 10^{-310}:\\ \;\;\;\;\mathsf{fma}\left(\log \left(-x\right) - \log \left(-y\right), \frac{x}{z}, -1\right) \cdot z\\ \mathbf{else}:\\ \;\;\;\;\left(\log x - \log y\right) \cdot x - z\\ \end{array} \]
        11. Add Preprocessing

        Alternative 8: 93.1% accurate, 0.5× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -3.6 \cdot 10^{+157}:\\ \;\;\;\;\left(\log \left(-x\right) - \log \left(-y\right)\right) \cdot x\\ \mathbf{elif}\;x \leq -6.2 \cdot 10^{-105}:\\ \;\;\;\;\log \left(\frac{y}{x}\right) \cdot \left(-x\right) - z\\ \mathbf{elif}\;x \leq -4 \cdot 10^{-308}:\\ \;\;\;\;-z\\ \mathbf{else}:\\ \;\;\;\;\left(\log x - \log y\right) \cdot x - z\\ \end{array} \end{array} \]
        (FPCore (x y z)
         :precision binary64
         (if (<= x -3.6e+157)
           (* (- (log (- x)) (log (- y))) x)
           (if (<= x -6.2e-105)
             (- (* (log (/ y x)) (- x)) z)
             (if (<= x -4e-308) (- z) (- (* (- (log x) (log y)) x) z)))))
        double code(double x, double y, double z) {
        	double tmp;
        	if (x <= -3.6e+157) {
        		tmp = (log(-x) - log(-y)) * x;
        	} else if (x <= -6.2e-105) {
        		tmp = (log((y / x)) * -x) - z;
        	} else if (x <= -4e-308) {
        		tmp = -z;
        	} else {
        		tmp = ((log(x) - log(y)) * x) - z;
        	}
        	return tmp;
        }
        
        real(8) function code(x, y, z)
            real(8), intent (in) :: x
            real(8), intent (in) :: y
            real(8), intent (in) :: z
            real(8) :: tmp
            if (x <= (-3.6d+157)) then
                tmp = (log(-x) - log(-y)) * x
            else if (x <= (-6.2d-105)) then
                tmp = (log((y / x)) * -x) - z
            else if (x <= (-4d-308)) then
                tmp = -z
            else
                tmp = ((log(x) - log(y)) * x) - z
            end if
            code = tmp
        end function
        
        public static double code(double x, double y, double z) {
        	double tmp;
        	if (x <= -3.6e+157) {
        		tmp = (Math.log(-x) - Math.log(-y)) * x;
        	} else if (x <= -6.2e-105) {
        		tmp = (Math.log((y / x)) * -x) - z;
        	} else if (x <= -4e-308) {
        		tmp = -z;
        	} else {
        		tmp = ((Math.log(x) - Math.log(y)) * x) - z;
        	}
        	return tmp;
        }
        
        def code(x, y, z):
        	tmp = 0
        	if x <= -3.6e+157:
        		tmp = (math.log(-x) - math.log(-y)) * x
        	elif x <= -6.2e-105:
        		tmp = (math.log((y / x)) * -x) - z
        	elif x <= -4e-308:
        		tmp = -z
        	else:
        		tmp = ((math.log(x) - math.log(y)) * x) - z
        	return tmp
        
        function code(x, y, z)
        	tmp = 0.0
        	if (x <= -3.6e+157)
        		tmp = Float64(Float64(log(Float64(-x)) - log(Float64(-y))) * x);
        	elseif (x <= -6.2e-105)
        		tmp = Float64(Float64(log(Float64(y / x)) * Float64(-x)) - z);
        	elseif (x <= -4e-308)
        		tmp = Float64(-z);
        	else
        		tmp = Float64(Float64(Float64(log(x) - log(y)) * x) - z);
        	end
        	return tmp
        end
        
        function tmp_2 = code(x, y, z)
        	tmp = 0.0;
        	if (x <= -3.6e+157)
        		tmp = (log(-x) - log(-y)) * x;
        	elseif (x <= -6.2e-105)
        		tmp = (log((y / x)) * -x) - z;
        	elseif (x <= -4e-308)
        		tmp = -z;
        	else
        		tmp = ((log(x) - log(y)) * x) - z;
        	end
        	tmp_2 = tmp;
        end
        
        code[x_, y_, z_] := If[LessEqual[x, -3.6e+157], N[(N[(N[Log[(-x)], $MachinePrecision] - N[Log[(-y)], $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision], If[LessEqual[x, -6.2e-105], N[(N[(N[Log[N[(y / x), $MachinePrecision]], $MachinePrecision] * (-x)), $MachinePrecision] - z), $MachinePrecision], If[LessEqual[x, -4e-308], (-z), N[(N[(N[(N[Log[x], $MachinePrecision] - N[Log[y], $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision] - z), $MachinePrecision]]]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;x \leq -3.6 \cdot 10^{+157}:\\
        \;\;\;\;\left(\log \left(-x\right) - \log \left(-y\right)\right) \cdot x\\
        
        \mathbf{elif}\;x \leq -6.2 \cdot 10^{-105}:\\
        \;\;\;\;\log \left(\frac{y}{x}\right) \cdot \left(-x\right) - z\\
        
        \mathbf{elif}\;x \leq -4 \cdot 10^{-308}:\\
        \;\;\;\;-z\\
        
        \mathbf{else}:\\
        \;\;\;\;\left(\log x - \log y\right) \cdot x - z\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 4 regimes
        2. if x < -3.60000000000000024e157

          1. Initial program 70.6%

            \[x \cdot \log \left(\frac{x}{y}\right) - z \]
          2. Add Preprocessing
          3. Taylor expanded in x around inf

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

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

              \[\leadsto \log \left(\frac{1}{y}\right) \cdot x + \color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{1}{x}\right)\right)\right)} \cdot x \]
            3. log-recN/A

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

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

              \[\leadsto \color{blue}{x \cdot \left(\log \left(\frac{1}{y}\right) + \log x\right)} \]
            6. +-commutativeN/A

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

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

              \[\leadsto \color{blue}{\left(\log x + \log \left(\frac{1}{y}\right)\right) \cdot x} \]
            9. log-recN/A

              \[\leadsto \left(\log x + \color{blue}{\left(\mathsf{neg}\left(\log y\right)\right)}\right) \cdot x \]
            10. unsub-negN/A

              \[\leadsto \color{blue}{\left(\log x - \log y\right)} \cdot x \]
            11. lower--.f64N/A

              \[\leadsto \color{blue}{\left(\log x - \log y\right)} \cdot x \]
            12. lower-log.f64N/A

              \[\leadsto \left(\color{blue}{\log x} - \log y\right) \cdot x \]
            13. lower-log.f640.0

              \[\leadsto \left(\log x - \color{blue}{\log y}\right) \cdot x \]
          5. Applied rewrites0.0%

            \[\leadsto \color{blue}{\left(\log x - \log y\right) \cdot x} \]
          6. Step-by-step derivation
            1. Applied rewrites98.8%

              \[\leadsto \left(\log \left(-x\right) - \log \left(-y\right)\right) \cdot x \]

            if -3.60000000000000024e157 < x < -6.20000000000000029e-105

            1. Initial program 94.1%

              \[x \cdot \log \left(\frac{x}{y}\right) - z \]
            2. Add Preprocessing
            3. Step-by-step derivation
              1. lift-log.f64N/A

                \[\leadsto x \cdot \color{blue}{\log \left(\frac{x}{y}\right)} - z \]
              2. lift-/.f64N/A

                \[\leadsto x \cdot \log \color{blue}{\left(\frac{x}{y}\right)} - z \]
              3. clear-numN/A

                \[\leadsto x \cdot \log \color{blue}{\left(\frac{1}{\frac{y}{x}}\right)} - z \]
              4. log-recN/A

                \[\leadsto x \cdot \color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{y}{x}\right)\right)\right)} - z \]
              5. lower-neg.f64N/A

                \[\leadsto x \cdot \color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{y}{x}\right)\right)\right)} - z \]
              6. lower-log.f64N/A

                \[\leadsto x \cdot \left(\mathsf{neg}\left(\color{blue}{\log \left(\frac{y}{x}\right)}\right)\right) - z \]
              7. lower-/.f6495.3

                \[\leadsto x \cdot \left(-\log \color{blue}{\left(\frac{y}{x}\right)}\right) - z \]
            4. Applied rewrites95.3%

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

            if -6.20000000000000029e-105 < x < -4.00000000000000013e-308

            1. Initial program 60.9%

              \[x \cdot \log \left(\frac{x}{y}\right) - z \]
            2. Add Preprocessing
            3. Taylor expanded in z around inf

              \[\leadsto \color{blue}{-1 \cdot z} \]
            4. Step-by-step derivation
              1. mul-1-negN/A

                \[\leadsto \color{blue}{\mathsf{neg}\left(z\right)} \]
              2. lower-neg.f6481.8

                \[\leadsto \color{blue}{-z} \]
            5. Applied rewrites81.8%

              \[\leadsto \color{blue}{-z} \]

            if -4.00000000000000013e-308 < x

            1. Initial program 73.3%

              \[x \cdot \log \left(\frac{x}{y}\right) - z \]
            2. Add Preprocessing
            3. Step-by-step derivation
              1. lift-log.f64N/A

                \[\leadsto x \cdot \color{blue}{\log \left(\frac{x}{y}\right)} - z \]
              2. lift-/.f64N/A

                \[\leadsto x \cdot \log \color{blue}{\left(\frac{x}{y}\right)} - z \]
              3. log-divN/A

                \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
              4. lower--.f64N/A

                \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
              5. lower-log.f64N/A

                \[\leadsto x \cdot \left(\color{blue}{\log x} - \log y\right) - z \]
              6. lower-log.f6499.6

                \[\leadsto x \cdot \left(\log x - \color{blue}{\log y}\right) - z \]
            4. Applied rewrites99.6%

              \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
          7. Recombined 4 regimes into one program.
          8. Final simplification95.8%

            \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -3.6 \cdot 10^{+157}:\\ \;\;\;\;\left(\log \left(-x\right) - \log \left(-y\right)\right) \cdot x\\ \mathbf{elif}\;x \leq -6.2 \cdot 10^{-105}:\\ \;\;\;\;\log \left(\frac{y}{x}\right) \cdot \left(-x\right) - z\\ \mathbf{elif}\;x \leq -4 \cdot 10^{-308}:\\ \;\;\;\;-z\\ \mathbf{else}:\\ \;\;\;\;\left(\log x - \log y\right) \cdot x - z\\ \end{array} \]
          9. Add Preprocessing

          Alternative 9: 90.8% accurate, 0.5× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -6.2 \cdot 10^{-105}:\\ \;\;\;\;\log \left(\frac{y}{x}\right) \cdot \left(-x\right) - z\\ \mathbf{elif}\;x \leq -4 \cdot 10^{-308}:\\ \;\;\;\;-z\\ \mathbf{else}:\\ \;\;\;\;\left(\log x - \log y\right) \cdot x - z\\ \end{array} \end{array} \]
          (FPCore (x y z)
           :precision binary64
           (if (<= x -6.2e-105)
             (- (* (log (/ y x)) (- x)) z)
             (if (<= x -4e-308) (- z) (- (* (- (log x) (log y)) x) z))))
          double code(double x, double y, double z) {
          	double tmp;
          	if (x <= -6.2e-105) {
          		tmp = (log((y / x)) * -x) - z;
          	} else if (x <= -4e-308) {
          		tmp = -z;
          	} else {
          		tmp = ((log(x) - log(y)) * x) - z;
          	}
          	return tmp;
          }
          
          real(8) function code(x, y, z)
              real(8), intent (in) :: x
              real(8), intent (in) :: y
              real(8), intent (in) :: z
              real(8) :: tmp
              if (x <= (-6.2d-105)) then
                  tmp = (log((y / x)) * -x) - z
              else if (x <= (-4d-308)) then
                  tmp = -z
              else
                  tmp = ((log(x) - log(y)) * x) - z
              end if
              code = tmp
          end function
          
          public static double code(double x, double y, double z) {
          	double tmp;
          	if (x <= -6.2e-105) {
          		tmp = (Math.log((y / x)) * -x) - z;
          	} else if (x <= -4e-308) {
          		tmp = -z;
          	} else {
          		tmp = ((Math.log(x) - Math.log(y)) * x) - z;
          	}
          	return tmp;
          }
          
          def code(x, y, z):
          	tmp = 0
          	if x <= -6.2e-105:
          		tmp = (math.log((y / x)) * -x) - z
          	elif x <= -4e-308:
          		tmp = -z
          	else:
          		tmp = ((math.log(x) - math.log(y)) * x) - z
          	return tmp
          
          function code(x, y, z)
          	tmp = 0.0
          	if (x <= -6.2e-105)
          		tmp = Float64(Float64(log(Float64(y / x)) * Float64(-x)) - z);
          	elseif (x <= -4e-308)
          		tmp = Float64(-z);
          	else
          		tmp = Float64(Float64(Float64(log(x) - log(y)) * x) - z);
          	end
          	return tmp
          end
          
          function tmp_2 = code(x, y, z)
          	tmp = 0.0;
          	if (x <= -6.2e-105)
          		tmp = (log((y / x)) * -x) - z;
          	elseif (x <= -4e-308)
          		tmp = -z;
          	else
          		tmp = ((log(x) - log(y)) * x) - z;
          	end
          	tmp_2 = tmp;
          end
          
          code[x_, y_, z_] := If[LessEqual[x, -6.2e-105], N[(N[(N[Log[N[(y / x), $MachinePrecision]], $MachinePrecision] * (-x)), $MachinePrecision] - z), $MachinePrecision], If[LessEqual[x, -4e-308], (-z), N[(N[(N[(N[Log[x], $MachinePrecision] - N[Log[y], $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision] - z), $MachinePrecision]]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          \mathbf{if}\;x \leq -6.2 \cdot 10^{-105}:\\
          \;\;\;\;\log \left(\frac{y}{x}\right) \cdot \left(-x\right) - z\\
          
          \mathbf{elif}\;x \leq -4 \cdot 10^{-308}:\\
          \;\;\;\;-z\\
          
          \mathbf{else}:\\
          \;\;\;\;\left(\log x - \log y\right) \cdot x - z\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 3 regimes
          2. if x < -6.20000000000000029e-105

            1. Initial program 84.6%

              \[x \cdot \log \left(\frac{x}{y}\right) - z \]
            2. Add Preprocessing
            3. Step-by-step derivation
              1. lift-log.f64N/A

                \[\leadsto x \cdot \color{blue}{\log \left(\frac{x}{y}\right)} - z \]
              2. lift-/.f64N/A

                \[\leadsto x \cdot \log \color{blue}{\left(\frac{x}{y}\right)} - z \]
              3. clear-numN/A

                \[\leadsto x \cdot \log \color{blue}{\left(\frac{1}{\frac{y}{x}}\right)} - z \]
              4. log-recN/A

                \[\leadsto x \cdot \color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{y}{x}\right)\right)\right)} - z \]
              5. lower-neg.f64N/A

                \[\leadsto x \cdot \color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{y}{x}\right)\right)\right)} - z \]
              6. lower-log.f64N/A

                \[\leadsto x \cdot \left(\mathsf{neg}\left(\color{blue}{\log \left(\frac{y}{x}\right)}\right)\right) - z \]
              7. lower-/.f6485.3

                \[\leadsto x \cdot \left(-\log \color{blue}{\left(\frac{y}{x}\right)}\right) - z \]
            4. Applied rewrites85.3%

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

            if -6.20000000000000029e-105 < x < -4.00000000000000013e-308

            1. Initial program 60.9%

              \[x \cdot \log \left(\frac{x}{y}\right) - z \]
            2. Add Preprocessing
            3. Taylor expanded in z around inf

              \[\leadsto \color{blue}{-1 \cdot z} \]
            4. Step-by-step derivation
              1. mul-1-negN/A

                \[\leadsto \color{blue}{\mathsf{neg}\left(z\right)} \]
              2. lower-neg.f6481.8

                \[\leadsto \color{blue}{-z} \]
            5. Applied rewrites81.8%

              \[\leadsto \color{blue}{-z} \]

            if -4.00000000000000013e-308 < x

            1. Initial program 73.3%

              \[x \cdot \log \left(\frac{x}{y}\right) - z \]
            2. Add Preprocessing
            3. Step-by-step derivation
              1. lift-log.f64N/A

                \[\leadsto x \cdot \color{blue}{\log \left(\frac{x}{y}\right)} - z \]
              2. lift-/.f64N/A

                \[\leadsto x \cdot \log \color{blue}{\left(\frac{x}{y}\right)} - z \]
              3. log-divN/A

                \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
              4. lower--.f64N/A

                \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
              5. lower-log.f64N/A

                \[\leadsto x \cdot \left(\color{blue}{\log x} - \log y\right) - z \]
              6. lower-log.f6499.6

                \[\leadsto x \cdot \left(\log x - \color{blue}{\log y}\right) - z \]
            4. Applied rewrites99.6%

              \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
          3. Recombined 3 regimes into one program.
          4. Final simplification91.9%

            \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -6.2 \cdot 10^{-105}:\\ \;\;\;\;\log \left(\frac{y}{x}\right) \cdot \left(-x\right) - z\\ \mathbf{elif}\;x \leq -4 \cdot 10^{-308}:\\ \;\;\;\;-z\\ \mathbf{else}:\\ \;\;\;\;\left(\log x - \log y\right) \cdot x - z\\ \end{array} \]
          5. Add Preprocessing

          Alternative 10: 66.2% accurate, 0.9× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} t_0 := \log \left(\frac{y}{x}\right) \cdot \left(-x\right)\\ \mathbf{if}\;x \leq -1.12 \cdot 10^{-27}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 4.4 \cdot 10^{+18}:\\ \;\;\;\;-z\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
          (FPCore (x y z)
           :precision binary64
           (let* ((t_0 (* (log (/ y x)) (- x))))
             (if (<= x -1.12e-27) t_0 (if (<= x 4.4e+18) (- z) t_0))))
          double code(double x, double y, double z) {
          	double t_0 = log((y / x)) * -x;
          	double tmp;
          	if (x <= -1.12e-27) {
          		tmp = t_0;
          	} else if (x <= 4.4e+18) {
          		tmp = -z;
          	} else {
          		tmp = t_0;
          	}
          	return tmp;
          }
          
          real(8) function code(x, y, z)
              real(8), intent (in) :: x
              real(8), intent (in) :: y
              real(8), intent (in) :: z
              real(8) :: t_0
              real(8) :: tmp
              t_0 = log((y / x)) * -x
              if (x <= (-1.12d-27)) then
                  tmp = t_0
              else if (x <= 4.4d+18) then
                  tmp = -z
              else
                  tmp = t_0
              end if
              code = tmp
          end function
          
          public static double code(double x, double y, double z) {
          	double t_0 = Math.log((y / x)) * -x;
          	double tmp;
          	if (x <= -1.12e-27) {
          		tmp = t_0;
          	} else if (x <= 4.4e+18) {
          		tmp = -z;
          	} else {
          		tmp = t_0;
          	}
          	return tmp;
          }
          
          def code(x, y, z):
          	t_0 = math.log((y / x)) * -x
          	tmp = 0
          	if x <= -1.12e-27:
          		tmp = t_0
          	elif x <= 4.4e+18:
          		tmp = -z
          	else:
          		tmp = t_0
          	return tmp
          
          function code(x, y, z)
          	t_0 = Float64(log(Float64(y / x)) * Float64(-x))
          	tmp = 0.0
          	if (x <= -1.12e-27)
          		tmp = t_0;
          	elseif (x <= 4.4e+18)
          		tmp = Float64(-z);
          	else
          		tmp = t_0;
          	end
          	return tmp
          end
          
          function tmp_2 = code(x, y, z)
          	t_0 = log((y / x)) * -x;
          	tmp = 0.0;
          	if (x <= -1.12e-27)
          		tmp = t_0;
          	elseif (x <= 4.4e+18)
          		tmp = -z;
          	else
          		tmp = t_0;
          	end
          	tmp_2 = tmp;
          end
          
          code[x_, y_, z_] := Block[{t$95$0 = N[(N[Log[N[(y / x), $MachinePrecision]], $MachinePrecision] * (-x)), $MachinePrecision]}, If[LessEqual[x, -1.12e-27], t$95$0, If[LessEqual[x, 4.4e+18], (-z), t$95$0]]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          t_0 := \log \left(\frac{y}{x}\right) \cdot \left(-x\right)\\
          \mathbf{if}\;x \leq -1.12 \cdot 10^{-27}:\\
          \;\;\;\;t\_0\\
          
          \mathbf{elif}\;x \leq 4.4 \cdot 10^{+18}:\\
          \;\;\;\;-z\\
          
          \mathbf{else}:\\
          \;\;\;\;t\_0\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if x < -1.1199999999999999e-27 or 4.4e18 < x

            1. Initial program 76.0%

              \[x \cdot \log \left(\frac{x}{y}\right) - z \]
            2. Add Preprocessing
            3. Taylor expanded in x around inf

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

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

                \[\leadsto \log \left(\frac{1}{y}\right) \cdot x + \color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{1}{x}\right)\right)\right)} \cdot x \]
              3. log-recN/A

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

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

                \[\leadsto \color{blue}{x \cdot \left(\log \left(\frac{1}{y}\right) + \log x\right)} \]
              6. +-commutativeN/A

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

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

                \[\leadsto \color{blue}{\left(\log x + \log \left(\frac{1}{y}\right)\right) \cdot x} \]
              9. log-recN/A

                \[\leadsto \left(\log x + \color{blue}{\left(\mathsf{neg}\left(\log y\right)\right)}\right) \cdot x \]
              10. unsub-negN/A

                \[\leadsto \color{blue}{\left(\log x - \log y\right)} \cdot x \]
              11. lower--.f64N/A

                \[\leadsto \color{blue}{\left(\log x - \log y\right)} \cdot x \]
              12. lower-log.f64N/A

                \[\leadsto \left(\color{blue}{\log x} - \log y\right) \cdot x \]
              13. lower-log.f6441.9

                \[\leadsto \left(\log x - \color{blue}{\log y}\right) \cdot x \]
            5. Applied rewrites41.9%

              \[\leadsto \color{blue}{\left(\log x - \log y\right) \cdot x} \]
            6. Step-by-step derivation
              1. Applied rewrites61.5%

                \[\leadsto \left(-\log \left(\frac{y}{x}\right)\right) \cdot x \]

              if -1.1199999999999999e-27 < x < 4.4e18

              1. Initial program 74.0%

                \[x \cdot \log \left(\frac{x}{y}\right) - z \]
              2. Add Preprocessing
              3. Taylor expanded in z around inf

                \[\leadsto \color{blue}{-1 \cdot z} \]
              4. Step-by-step derivation
                1. mul-1-negN/A

                  \[\leadsto \color{blue}{\mathsf{neg}\left(z\right)} \]
                2. lower-neg.f6480.5

                  \[\leadsto \color{blue}{-z} \]
              5. Applied rewrites80.5%

                \[\leadsto \color{blue}{-z} \]
            7. Recombined 2 regimes into one program.
            8. Final simplification70.0%

              \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.12 \cdot 10^{-27}:\\ \;\;\;\;\log \left(\frac{y}{x}\right) \cdot \left(-x\right)\\ \mathbf{elif}\;x \leq 4.4 \cdot 10^{+18}:\\ \;\;\;\;-z\\ \mathbf{else}:\\ \;\;\;\;\log \left(\frac{y}{x}\right) \cdot \left(-x\right)\\ \end{array} \]
            9. Add Preprocessing

            Alternative 11: 65.6% accurate, 0.9× speedup?

            \[\begin{array}{l} \\ \begin{array}{l} t_0 := \log \left(\frac{x}{y}\right) \cdot x\\ \mathbf{if}\;x \leq -1.12 \cdot 10^{-27}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 4.4 \cdot 10^{+18}:\\ \;\;\;\;-z\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
            (FPCore (x y z)
             :precision binary64
             (let* ((t_0 (* (log (/ x y)) x)))
               (if (<= x -1.12e-27) t_0 (if (<= x 4.4e+18) (- z) t_0))))
            double code(double x, double y, double z) {
            	double t_0 = log((x / y)) * x;
            	double tmp;
            	if (x <= -1.12e-27) {
            		tmp = t_0;
            	} else if (x <= 4.4e+18) {
            		tmp = -z;
            	} else {
            		tmp = t_0;
            	}
            	return tmp;
            }
            
            real(8) function code(x, y, z)
                real(8), intent (in) :: x
                real(8), intent (in) :: y
                real(8), intent (in) :: z
                real(8) :: t_0
                real(8) :: tmp
                t_0 = log((x / y)) * x
                if (x <= (-1.12d-27)) then
                    tmp = t_0
                else if (x <= 4.4d+18) then
                    tmp = -z
                else
                    tmp = t_0
                end if
                code = tmp
            end function
            
            public static double code(double x, double y, double z) {
            	double t_0 = Math.log((x / y)) * x;
            	double tmp;
            	if (x <= -1.12e-27) {
            		tmp = t_0;
            	} else if (x <= 4.4e+18) {
            		tmp = -z;
            	} else {
            		tmp = t_0;
            	}
            	return tmp;
            }
            
            def code(x, y, z):
            	t_0 = math.log((x / y)) * x
            	tmp = 0
            	if x <= -1.12e-27:
            		tmp = t_0
            	elif x <= 4.4e+18:
            		tmp = -z
            	else:
            		tmp = t_0
            	return tmp
            
            function code(x, y, z)
            	t_0 = Float64(log(Float64(x / y)) * x)
            	tmp = 0.0
            	if (x <= -1.12e-27)
            		tmp = t_0;
            	elseif (x <= 4.4e+18)
            		tmp = Float64(-z);
            	else
            		tmp = t_0;
            	end
            	return tmp
            end
            
            function tmp_2 = code(x, y, z)
            	t_0 = log((x / y)) * x;
            	tmp = 0.0;
            	if (x <= -1.12e-27)
            		tmp = t_0;
            	elseif (x <= 4.4e+18)
            		tmp = -z;
            	else
            		tmp = t_0;
            	end
            	tmp_2 = tmp;
            end
            
            code[x_, y_, z_] := Block[{t$95$0 = N[(N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision] * x), $MachinePrecision]}, If[LessEqual[x, -1.12e-27], t$95$0, If[LessEqual[x, 4.4e+18], (-z), t$95$0]]]
            
            \begin{array}{l}
            
            \\
            \begin{array}{l}
            t_0 := \log \left(\frac{x}{y}\right) \cdot x\\
            \mathbf{if}\;x \leq -1.12 \cdot 10^{-27}:\\
            \;\;\;\;t\_0\\
            
            \mathbf{elif}\;x \leq 4.4 \cdot 10^{+18}:\\
            \;\;\;\;-z\\
            
            \mathbf{else}:\\
            \;\;\;\;t\_0\\
            
            
            \end{array}
            \end{array}
            
            Derivation
            1. Split input into 2 regimes
            2. if x < -1.1199999999999999e-27 or 4.4e18 < x

              1. Initial program 76.0%

                \[x \cdot \log \left(\frac{x}{y}\right) - z \]
              2. Add Preprocessing
              3. Taylor expanded in z around 0

                \[\leadsto \color{blue}{x \cdot \log \left(\frac{x}{y}\right)} \]
              4. Step-by-step derivation
                1. *-commutativeN/A

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

                  \[\leadsto \color{blue}{\log \left(\frac{x}{y}\right) \cdot x} \]
                3. lower-log.f64N/A

                  \[\leadsto \color{blue}{\log \left(\frac{x}{y}\right)} \cdot x \]
                4. lower-/.f6459.9

                  \[\leadsto \log \color{blue}{\left(\frac{x}{y}\right)} \cdot x \]
              5. Applied rewrites59.9%

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

              if -1.1199999999999999e-27 < x < 4.4e18

              1. Initial program 74.0%

                \[x \cdot \log \left(\frac{x}{y}\right) - z \]
              2. Add Preprocessing
              3. Taylor expanded in z around inf

                \[\leadsto \color{blue}{-1 \cdot z} \]
              4. Step-by-step derivation
                1. mul-1-negN/A

                  \[\leadsto \color{blue}{\mathsf{neg}\left(z\right)} \]
                2. lower-neg.f6480.5

                  \[\leadsto \color{blue}{-z} \]
              5. Applied rewrites80.5%

                \[\leadsto \color{blue}{-z} \]
            3. Recombined 2 regimes into one program.
            4. Add Preprocessing

            Alternative 12: 49.8% accurate, 40.0× speedup?

            \[\begin{array}{l} \\ -z \end{array} \]
            (FPCore (x y z) :precision binary64 (- z))
            double code(double x, double y, double z) {
            	return -z;
            }
            
            real(8) function code(x, y, z)
                real(8), intent (in) :: x
                real(8), intent (in) :: y
                real(8), intent (in) :: z
                code = -z
            end function
            
            public static double code(double x, double y, double z) {
            	return -z;
            }
            
            def code(x, y, z):
            	return -z
            
            function code(x, y, z)
            	return Float64(-z)
            end
            
            function tmp = code(x, y, z)
            	tmp = -z;
            end
            
            code[x_, y_, z_] := (-z)
            
            \begin{array}{l}
            
            \\
            -z
            \end{array}
            
            Derivation
            1. Initial program 75.1%

              \[x \cdot \log \left(\frac{x}{y}\right) - z \]
            2. Add Preprocessing
            3. Taylor expanded in z around inf

              \[\leadsto \color{blue}{-1 \cdot z} \]
            4. Step-by-step derivation
              1. mul-1-negN/A

                \[\leadsto \color{blue}{\mathsf{neg}\left(z\right)} \]
              2. lower-neg.f6446.4

                \[\leadsto \color{blue}{-z} \]
            5. Applied rewrites46.4%

              \[\leadsto \color{blue}{-z} \]
            6. Add Preprocessing

            Alternative 13: 2.2% accurate, 120.0× speedup?

            \[\begin{array}{l} \\ z \end{array} \]
            (FPCore (x y z) :precision binary64 z)
            double code(double x, double y, double z) {
            	return z;
            }
            
            real(8) function code(x, y, z)
                real(8), intent (in) :: x
                real(8), intent (in) :: y
                real(8), intent (in) :: z
                code = z
            end function
            
            public static double code(double x, double y, double z) {
            	return z;
            }
            
            def code(x, y, z):
            	return z
            
            function code(x, y, z)
            	return z
            end
            
            function tmp = code(x, y, z)
            	tmp = z;
            end
            
            code[x_, y_, z_] := z
            
            \begin{array}{l}
            
            \\
            z
            \end{array}
            
            Derivation
            1. Initial program 75.1%

              \[x \cdot \log \left(\frac{x}{y}\right) - z \]
            2. Add Preprocessing
            3. Taylor expanded in z around inf

              \[\leadsto \color{blue}{-1 \cdot z} \]
            4. Step-by-step derivation
              1. mul-1-negN/A

                \[\leadsto \color{blue}{\mathsf{neg}\left(z\right)} \]
              2. lower-neg.f6446.4

                \[\leadsto \color{blue}{-z} \]
            5. Applied rewrites46.4%

              \[\leadsto \color{blue}{-z} \]
            6. Step-by-step derivation
              1. Applied rewrites25.2%

                \[\leadsto \frac{\left(-z\right) \cdot z}{\color{blue}{0 + z}} \]
              2. Step-by-step derivation
                1. Applied rewrites2.3%

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

                Developer Target 1: 88.5% accurate, 0.6× speedup?

                \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y < 7.595077799083773 \cdot 10^{-308}:\\ \;\;\;\;x \cdot \log \left(\frac{x}{y}\right) - z\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(\log x - \log y\right) - z\\ \end{array} \end{array} \]
                (FPCore (x y z)
                 :precision binary64
                 (if (< y 7.595077799083773e-308)
                   (- (* x (log (/ x y))) z)
                   (- (* x (- (log x) (log y))) z)))
                double code(double x, double y, double z) {
                	double tmp;
                	if (y < 7.595077799083773e-308) {
                		tmp = (x * log((x / y))) - z;
                	} else {
                		tmp = (x * (log(x) - log(y))) - z;
                	}
                	return tmp;
                }
                
                real(8) function code(x, y, z)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    real(8), intent (in) :: z
                    real(8) :: tmp
                    if (y < 7.595077799083773d-308) then
                        tmp = (x * log((x / y))) - z
                    else
                        tmp = (x * (log(x) - log(y))) - z
                    end if
                    code = tmp
                end function
                
                public static double code(double x, double y, double z) {
                	double tmp;
                	if (y < 7.595077799083773e-308) {
                		tmp = (x * Math.log((x / y))) - z;
                	} else {
                		tmp = (x * (Math.log(x) - Math.log(y))) - z;
                	}
                	return tmp;
                }
                
                def code(x, y, z):
                	tmp = 0
                	if y < 7.595077799083773e-308:
                		tmp = (x * math.log((x / y))) - z
                	else:
                		tmp = (x * (math.log(x) - math.log(y))) - z
                	return tmp
                
                function code(x, y, z)
                	tmp = 0.0
                	if (y < 7.595077799083773e-308)
                		tmp = Float64(Float64(x * log(Float64(x / y))) - z);
                	else
                		tmp = Float64(Float64(x * Float64(log(x) - log(y))) - z);
                	end
                	return tmp
                end
                
                function tmp_2 = code(x, y, z)
                	tmp = 0.0;
                	if (y < 7.595077799083773e-308)
                		tmp = (x * log((x / y))) - z;
                	else
                		tmp = (x * (log(x) - log(y))) - z;
                	end
                	tmp_2 = tmp;
                end
                
                code[x_, y_, z_] := If[Less[y, 7.595077799083773e-308], N[(N[(x * N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision], N[(N[(x * N[(N[Log[x], $MachinePrecision] - N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]]
                
                \begin{array}{l}
                
                \\
                \begin{array}{l}
                \mathbf{if}\;y < 7.595077799083773 \cdot 10^{-308}:\\
                \;\;\;\;x \cdot \log \left(\frac{x}{y}\right) - z\\
                
                \mathbf{else}:\\
                \;\;\;\;x \cdot \left(\log x - \log y\right) - z\\
                
                
                \end{array}
                \end{array}
                

                Reproduce

                ?
                herbie shell --seed 2024235 
                (FPCore (x y z)
                  :name "Numeric.SpecFunctions.Extra:bd0 from math-functions-0.1.5.2"
                  :precision binary64
                
                  :alt
                  (! :herbie-platform default (if (< y 7595077799083773/100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000) (- (* x (log (/ x y))) z) (- (* x (- (log x) (log y))) z)))
                
                  (- (* x (log (/ x y))) z))