Numeric.SpecFunctions:logGammaL from math-functions-0.1.5.2

Percentage Accurate: 99.6% → 99.6%
Time: 14.1s
Alternatives: 15
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (+ (- (+ (log (+ x y)) (log z)) t) (* (- a 0.5) (log t))))
double code(double x, double y, double z, double t, double a) {
	return ((log((x + y)) + log(z)) - t) + ((a - 0.5) * log(t));
}
real(8) function code(x, y, z, t, a)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8), intent (in) :: a
    code = ((log((x + y)) + log(z)) - t) + ((a - 0.5d0) * log(t))
end function
public static double code(double x, double y, double z, double t, double a) {
	return ((Math.log((x + y)) + Math.log(z)) - t) + ((a - 0.5) * Math.log(t));
}
def code(x, y, z, t, a):
	return ((math.log((x + y)) + math.log(z)) - t) + ((a - 0.5) * math.log(t))
function code(x, y, z, t, a)
	return Float64(Float64(Float64(log(Float64(x + y)) + log(z)) - t) + Float64(Float64(a - 0.5) * log(t)))
end
function tmp = code(x, y, z, t, a)
	tmp = ((log((x + y)) + log(z)) - t) + ((a - 0.5) * log(t));
end
code[x_, y_, z_, t_, a_] := N[(N[(N[(N[Log[N[(x + y), $MachinePrecision]], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision] + N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t
\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 15 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: 99.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (+ (- (+ (log (+ x y)) (log z)) t) (* (- a 0.5) (log t))))
double code(double x, double y, double z, double t, double a) {
	return ((log((x + y)) + log(z)) - t) + ((a - 0.5) * log(t));
}
real(8) function code(x, y, z, t, a)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8), intent (in) :: a
    code = ((log((x + y)) + log(z)) - t) + ((a - 0.5d0) * log(t))
end function
public static double code(double x, double y, double z, double t, double a) {
	return ((Math.log((x + y)) + Math.log(z)) - t) + ((a - 0.5) * Math.log(t));
}
def code(x, y, z, t, a):
	return ((math.log((x + y)) + math.log(z)) - t) + ((a - 0.5) * math.log(t))
function code(x, y, z, t, a)
	return Float64(Float64(Float64(log(Float64(x + y)) + log(z)) - t) + Float64(Float64(a - 0.5) * log(t)))
end
function tmp = code(x, y, z, t, a)
	tmp = ((log((x + y)) + log(z)) - t) + ((a - 0.5) * log(t));
end
code[x_, y_, z_, t_, a_] := N[(N[(N[(N[Log[N[(x + y), $MachinePrecision]], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision] + N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t
\end{array}

Alternative 1: 99.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \log t \cdot \left(a - 0.5\right) + \left(\left(\log z + \log \left(y + x\right)\right) - t\right) \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (+ (* (log t) (- a 0.5)) (- (+ (log z) (log (+ y x))) t)))
double code(double x, double y, double z, double t, double a) {
	return (log(t) * (a - 0.5)) + ((log(z) + log((y + x))) - t);
}
real(8) function code(x, y, z, t, a)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8), intent (in) :: a
    code = (log(t) * (a - 0.5d0)) + ((log(z) + log((y + x))) - t)
end function
public static double code(double x, double y, double z, double t, double a) {
	return (Math.log(t) * (a - 0.5)) + ((Math.log(z) + Math.log((y + x))) - t);
}
def code(x, y, z, t, a):
	return (math.log(t) * (a - 0.5)) + ((math.log(z) + math.log((y + x))) - t)
function code(x, y, z, t, a)
	return Float64(Float64(log(t) * Float64(a - 0.5)) + Float64(Float64(log(z) + log(Float64(y + x))) - t))
end
function tmp = code(x, y, z, t, a)
	tmp = (log(t) * (a - 0.5)) + ((log(z) + log((y + x))) - t);
end
code[x_, y_, z_, t_, a_] := N[(N[(N[Log[t], $MachinePrecision] * N[(a - 0.5), $MachinePrecision]), $MachinePrecision] + N[(N[(N[Log[z], $MachinePrecision] + N[Log[N[(y + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\log t \cdot \left(a - 0.5\right) + \left(\left(\log z + \log \left(y + x\right)\right) - t\right)
\end{array}
Derivation
  1. Initial program 99.6%

    \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
  2. Add Preprocessing
  3. Final simplification99.6%

    \[\leadsto \log t \cdot \left(a - 0.5\right) + \left(\left(\log z + \log \left(y + x\right)\right) - t\right) \]
  4. Add Preprocessing

Alternative 2: 73.8% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \log t \cdot \left(a - 0.5\right) + \left(\left(\log z + \log \left(y + x\right)\right) - t\right)\\ t_2 := \left(\log t \cdot a + \log y\right) - t\\ \mathbf{if}\;t\_1 \leq -20000000000000:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq 880:\\ \;\;\;\;\mathsf{fma}\left(\log t, -0.5, \log \left(\left(y + x\right) \cdot z\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (let* ((t_1 (+ (* (log t) (- a 0.5)) (- (+ (log z) (log (+ y x))) t)))
        (t_2 (- (+ (* (log t) a) (log y)) t)))
   (if (<= t_1 -20000000000000.0)
     t_2
     (if (<= t_1 880.0) (- (fma (log t) -0.5 (log (* (+ y x) z))) t) t_2))))
double code(double x, double y, double z, double t, double a) {
	double t_1 = (log(t) * (a - 0.5)) + ((log(z) + log((y + x))) - t);
	double t_2 = ((log(t) * a) + log(y)) - t;
	double tmp;
	if (t_1 <= -20000000000000.0) {
		tmp = t_2;
	} else if (t_1 <= 880.0) {
		tmp = fma(log(t), -0.5, log(((y + x) * z))) - t;
	} else {
		tmp = t_2;
	}
	return tmp;
}
function code(x, y, z, t, a)
	t_1 = Float64(Float64(log(t) * Float64(a - 0.5)) + Float64(Float64(log(z) + log(Float64(y + x))) - t))
	t_2 = Float64(Float64(Float64(log(t) * a) + log(y)) - t)
	tmp = 0.0
	if (t_1 <= -20000000000000.0)
		tmp = t_2;
	elseif (t_1 <= 880.0)
		tmp = Float64(fma(log(t), -0.5, log(Float64(Float64(y + x) * z))) - t);
	else
		tmp = t_2;
	end
	return tmp
end
code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[(N[Log[t], $MachinePrecision] * N[(a - 0.5), $MachinePrecision]), $MachinePrecision] + N[(N[(N[Log[z], $MachinePrecision] + N[Log[N[(y + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]}, If[LessEqual[t$95$1, -20000000000000.0], t$95$2, If[LessEqual[t$95$1, 880.0], N[(N[(N[Log[t], $MachinePrecision] * -0.5 + N[Log[N[(N[(y + x), $MachinePrecision] * z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision], t$95$2]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \log t \cdot \left(a - 0.5\right) + \left(\left(\log z + \log \left(y + x\right)\right) - t\right)\\
t_2 := \left(\log t \cdot a + \log y\right) - t\\
\mathbf{if}\;t\_1 \leq -20000000000000:\\
\;\;\;\;t\_2\\

\mathbf{elif}\;t\_1 \leq 880:\\
\;\;\;\;\mathsf{fma}\left(\log t, -0.5, \log \left(\left(y + x\right) \cdot z\right)\right) - t\\

\mathbf{else}:\\
\;\;\;\;t\_2\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (-.f64 (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) t) (*.f64 (-.f64 a #s(literal 1/2 binary64)) (log.f64 t))) < -2e13 or 880 < (+.f64 (-.f64 (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) t) (*.f64 (-.f64 a #s(literal 1/2 binary64)) (log.f64 t)))

    1. Initial program 99.8%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Add Preprocessing
    3. Taylor expanded in y around inf

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

        \[\leadsto \color{blue}{\left(\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right)} - t \]
      2. associate--l+N/A

        \[\leadsto \color{blue}{\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right)} \]
      3. +-commutativeN/A

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

        \[\leadsto \left(\color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{1}{y}\right)\right)\right)} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
      5. log-recN/A

        \[\leadsto \left(\left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(\log y\right)\right)}\right)\right) + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
      6. remove-double-negN/A

        \[\leadsto \left(\color{blue}{\log y} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
      7. associate--l+N/A

        \[\leadsto \color{blue}{\left(\left(\log y + \log z\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right) - t} \]
      8. associate-+r+N/A

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

        \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
    5. Applied rewrites64.2%

      \[\leadsto \color{blue}{\left(\log y + \mathsf{fma}\left(a - 0.5, \log t, \log z\right)\right) - t} \]
    6. Taylor expanded in a around inf

      \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
    7. Step-by-step derivation
      1. Applied rewrites60.2%

        \[\leadsto \left(\log y + a \cdot \log t\right) - t \]

      if -2e13 < (+.f64 (-.f64 (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) t) (*.f64 (-.f64 a #s(literal 1/2 binary64)) (log.f64 t))) < 880

      1. Initial program 99.0%

        \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift-+.f64N/A

          \[\leadsto \color{blue}{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - \frac{1}{2}\right) \cdot \log t} \]
        2. flip-+N/A

          \[\leadsto \color{blue}{\frac{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) \cdot \left(\left(\log \left(x + y\right) + \log z\right) - t\right) - \left(\left(a - \frac{1}{2}\right) \cdot \log t\right) \cdot \left(\left(a - \frac{1}{2}\right) \cdot \log t\right)}{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) - \left(a - \frac{1}{2}\right) \cdot \log t}} \]
        3. clear-numN/A

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

          \[\leadsto \color{blue}{\frac{1}{\frac{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) - \left(a - \frac{1}{2}\right) \cdot \log t}{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) \cdot \left(\left(\log \left(x + y\right) + \log z\right) - t\right) - \left(\left(a - \frac{1}{2}\right) \cdot \log t\right) \cdot \left(\left(a - \frac{1}{2}\right) \cdot \log t\right)}}} \]
        5. clear-numN/A

          \[\leadsto \frac{1}{\color{blue}{\frac{1}{\frac{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) \cdot \left(\left(\log \left(x + y\right) + \log z\right) - t\right) - \left(\left(a - \frac{1}{2}\right) \cdot \log t\right) \cdot \left(\left(a - \frac{1}{2}\right) \cdot \log t\right)}{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) - \left(a - \frac{1}{2}\right) \cdot \log t}}}} \]
      4. Applied rewrites92.3%

        \[\leadsto \color{blue}{\frac{1}{\frac{1}{\mathsf{fma}\left(\log t, a - 0.5, \log \left(z \cdot \left(y + x\right)\right) - t\right)}}} \]
      5. Taylor expanded in a around 0

        \[\leadsto \color{blue}{\left(\log \left(z \cdot \left(x + y\right)\right) + \frac{-1}{2} \cdot \log t\right) - t} \]
      6. Step-by-step derivation
        1. lower--.f64N/A

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

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

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

          \[\leadsto \color{blue}{\mathsf{fma}\left(\log t, \frac{-1}{2}, \log \left(z \cdot \left(x + y\right)\right)\right)} - t \]
        5. lower-log.f64N/A

          \[\leadsto \mathsf{fma}\left(\color{blue}{\log t}, \frac{-1}{2}, \log \left(z \cdot \left(x + y\right)\right)\right) - t \]
        6. lower-log.f64N/A

          \[\leadsto \mathsf{fma}\left(\log t, \frac{-1}{2}, \color{blue}{\log \left(z \cdot \left(x + y\right)\right)}\right) - t \]
        7. *-commutativeN/A

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

          \[\leadsto \mathsf{fma}\left(\log t, \frac{-1}{2}, \log \color{blue}{\left(\left(x + y\right) \cdot z\right)}\right) - t \]
        9. +-commutativeN/A

          \[\leadsto \mathsf{fma}\left(\log t, \frac{-1}{2}, \log \left(\color{blue}{\left(y + x\right)} \cdot z\right)\right) - t \]
        10. lower-+.f6491.0

          \[\leadsto \mathsf{fma}\left(\log t, -0.5, \log \left(\color{blue}{\left(y + x\right)} \cdot z\right)\right) - t \]
      7. Applied rewrites91.0%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\log t, -0.5, \log \left(\left(y + x\right) \cdot z\right)\right) - t} \]
    8. Recombined 2 regimes into one program.
    9. Final simplification65.9%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\log t \cdot \left(a - 0.5\right) + \left(\left(\log z + \log \left(y + x\right)\right) - t\right) \leq -20000000000000:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \mathbf{elif}\;\log t \cdot \left(a - 0.5\right) + \left(\left(\log z + \log \left(y + x\right)\right) - t\right) \leq 880:\\ \;\;\;\;\mathsf{fma}\left(\log t, -0.5, \log \left(\left(y + x\right) \cdot z\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \end{array} \]
    10. Add Preprocessing

    Alternative 3: 89.1% accurate, 0.5× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_1 := \log z + \log \left(y + x\right)\\ t_2 := \left(\log t \cdot a + \log y\right) - t\\ \mathbf{if}\;t\_1 \leq -750:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq 720:\\ \;\;\;\;\mathsf{fma}\left(\log t, a - 0.5, \log \left(\left(y + x\right) \cdot z\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \end{array} \]
    (FPCore (x y z t a)
     :precision binary64
     (let* ((t_1 (+ (log z) (log (+ y x)))) (t_2 (- (+ (* (log t) a) (log y)) t)))
       (if (<= t_1 -750.0)
         t_2
         (if (<= t_1 720.0)
           (- (fma (log t) (- a 0.5) (log (* (+ y x) z))) t)
           t_2))))
    double code(double x, double y, double z, double t, double a) {
    	double t_1 = log(z) + log((y + x));
    	double t_2 = ((log(t) * a) + log(y)) - t;
    	double tmp;
    	if (t_1 <= -750.0) {
    		tmp = t_2;
    	} else if (t_1 <= 720.0) {
    		tmp = fma(log(t), (a - 0.5), log(((y + x) * z))) - t;
    	} else {
    		tmp = t_2;
    	}
    	return tmp;
    }
    
    function code(x, y, z, t, a)
    	t_1 = Float64(log(z) + log(Float64(y + x)))
    	t_2 = Float64(Float64(Float64(log(t) * a) + log(y)) - t)
    	tmp = 0.0
    	if (t_1 <= -750.0)
    		tmp = t_2;
    	elseif (t_1 <= 720.0)
    		tmp = Float64(fma(log(t), Float64(a - 0.5), log(Float64(Float64(y + x) * z))) - t);
    	else
    		tmp = t_2;
    	end
    	return tmp
    end
    
    code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[Log[z], $MachinePrecision] + N[Log[N[(y + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]}, If[LessEqual[t$95$1, -750.0], t$95$2, If[LessEqual[t$95$1, 720.0], N[(N[(N[Log[t], $MachinePrecision] * N[(a - 0.5), $MachinePrecision] + N[Log[N[(N[(y + x), $MachinePrecision] * z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision], t$95$2]]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_1 := \log z + \log \left(y + x\right)\\
    t_2 := \left(\log t \cdot a + \log y\right) - t\\
    \mathbf{if}\;t\_1 \leq -750:\\
    \;\;\;\;t\_2\\
    
    \mathbf{elif}\;t\_1 \leq 720:\\
    \;\;\;\;\mathsf{fma}\left(\log t, a - 0.5, \log \left(\left(y + x\right) \cdot z\right)\right) - t\\
    
    \mathbf{else}:\\
    \;\;\;\;t\_2\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < -750 or 720 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 z))

      1. Initial program 99.8%

        \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
      2. Add Preprocessing
      3. Taylor expanded in y around inf

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

          \[\leadsto \color{blue}{\left(\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right)} - t \]
        2. associate--l+N/A

          \[\leadsto \color{blue}{\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right)} \]
        3. +-commutativeN/A

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

          \[\leadsto \left(\color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{1}{y}\right)\right)\right)} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
        5. log-recN/A

          \[\leadsto \left(\left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(\log y\right)\right)}\right)\right) + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
        6. remove-double-negN/A

          \[\leadsto \left(\color{blue}{\log y} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
        7. associate--l+N/A

          \[\leadsto \color{blue}{\left(\left(\log y + \log z\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right) - t} \]
        8. associate-+r+N/A

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

          \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
      5. Applied rewrites58.0%

        \[\leadsto \color{blue}{\left(\log y + \mathsf{fma}\left(a - 0.5, \log t, \log z\right)\right) - t} \]
      6. Taylor expanded in a around inf

        \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
      7. Step-by-step derivation
        1. Applied rewrites44.9%

          \[\leadsto \left(\log y + a \cdot \log t\right) - t \]

        if -750 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < 720

        1. Initial program 99.6%

          \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
        2. Add Preprocessing
        3. Step-by-step derivation
          1. lift-+.f64N/A

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

            \[\leadsto \color{blue}{\left(a - \frac{1}{2}\right) \cdot \log t + \left(\left(\log \left(x + y\right) + \log z\right) - t\right)} \]
          3. lift--.f64N/A

            \[\leadsto \left(a - \frac{1}{2}\right) \cdot \log t + \color{blue}{\left(\left(\log \left(x + y\right) + \log z\right) - t\right)} \]
          4. associate-+r-N/A

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

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

            \[\leadsto \left(\color{blue}{\left(a - \frac{1}{2}\right) \cdot \log t} + \left(\log \left(x + y\right) + \log z\right)\right) - t \]
          7. *-commutativeN/A

            \[\leadsto \left(\color{blue}{\log t \cdot \left(a - \frac{1}{2}\right)} + \left(\log \left(x + y\right) + \log z\right)\right) - t \]
          8. lower-fma.f6499.6

            \[\leadsto \color{blue}{\mathsf{fma}\left(\log t, a - 0.5, \log \left(x + y\right) + \log z\right)} - t \]
          9. lift-+.f64N/A

            \[\leadsto \mathsf{fma}\left(\log t, a - \frac{1}{2}, \color{blue}{\log \left(x + y\right) + \log z}\right) - t \]
          10. lift-log.f64N/A

            \[\leadsto \mathsf{fma}\left(\log t, a - \frac{1}{2}, \color{blue}{\log \left(x + y\right)} + \log z\right) - t \]
          11. lift-log.f64N/A

            \[\leadsto \mathsf{fma}\left(\log t, a - \frac{1}{2}, \log \left(x + y\right) + \color{blue}{\log z}\right) - t \]
          12. sum-logN/A

            \[\leadsto \mathsf{fma}\left(\log t, a - \frac{1}{2}, \color{blue}{\log \left(\left(x + y\right) \cdot z\right)}\right) - t \]
          13. lower-log.f64N/A

            \[\leadsto \mathsf{fma}\left(\log t, a - \frac{1}{2}, \color{blue}{\log \left(\left(x + y\right) \cdot z\right)}\right) - t \]
          14. *-commutativeN/A

            \[\leadsto \mathsf{fma}\left(\log t, a - \frac{1}{2}, \log \color{blue}{\left(z \cdot \left(x + y\right)\right)}\right) - t \]
          15. lower-*.f6499.4

            \[\leadsto \mathsf{fma}\left(\log t, a - 0.5, \log \color{blue}{\left(z \cdot \left(x + y\right)\right)}\right) - t \]
          16. lift-+.f64N/A

            \[\leadsto \mathsf{fma}\left(\log t, a - \frac{1}{2}, \log \left(z \cdot \color{blue}{\left(x + y\right)}\right)\right) - t \]
          17. +-commutativeN/A

            \[\leadsto \mathsf{fma}\left(\log t, a - \frac{1}{2}, \log \left(z \cdot \color{blue}{\left(y + x\right)}\right)\right) - t \]
          18. lower-+.f6499.4

            \[\leadsto \mathsf{fma}\left(\log t, a - 0.5, \log \left(z \cdot \color{blue}{\left(y + x\right)}\right)\right) - t \]
        4. Applied rewrites99.4%

          \[\leadsto \color{blue}{\mathsf{fma}\left(\log t, a - 0.5, \log \left(z \cdot \left(y + x\right)\right)\right) - t} \]
      8. Recombined 2 regimes into one program.
      9. Final simplification83.3%

        \[\leadsto \begin{array}{l} \mathbf{if}\;\log z + \log \left(y + x\right) \leq -750:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \mathbf{elif}\;\log z + \log \left(y + x\right) \leq 720:\\ \;\;\;\;\mathsf{fma}\left(\log t, a - 0.5, \log \left(\left(y + x\right) \cdot z\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \end{array} \]
      10. Add Preprocessing

      Alternative 4: 64.0% accurate, 0.5× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} t_1 := \log z + \log \left(y + x\right)\\ t_2 := \left(\log t \cdot a + \log y\right) - t\\ \mathbf{if}\;t\_1 \leq -750:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq 720:\\ \;\;\;\;\left(\log \left(z \cdot y\right) + \log t \cdot \left(a - 0.5\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \end{array} \]
      (FPCore (x y z t a)
       :precision binary64
       (let* ((t_1 (+ (log z) (log (+ y x)))) (t_2 (- (+ (* (log t) a) (log y)) t)))
         (if (<= t_1 -750.0)
           t_2
           (if (<= t_1 720.0) (- (+ (log (* z y)) (* (log t) (- a 0.5))) t) t_2))))
      double code(double x, double y, double z, double t, double a) {
      	double t_1 = log(z) + log((y + x));
      	double t_2 = ((log(t) * a) + log(y)) - t;
      	double tmp;
      	if (t_1 <= -750.0) {
      		tmp = t_2;
      	} else if (t_1 <= 720.0) {
      		tmp = (log((z * y)) + (log(t) * (a - 0.5))) - t;
      	} else {
      		tmp = t_2;
      	}
      	return tmp;
      }
      
      real(8) function code(x, y, z, t, a)
          real(8), intent (in) :: x
          real(8), intent (in) :: y
          real(8), intent (in) :: z
          real(8), intent (in) :: t
          real(8), intent (in) :: a
          real(8) :: t_1
          real(8) :: t_2
          real(8) :: tmp
          t_1 = log(z) + log((y + x))
          t_2 = ((log(t) * a) + log(y)) - t
          if (t_1 <= (-750.0d0)) then
              tmp = t_2
          else if (t_1 <= 720.0d0) then
              tmp = (log((z * y)) + (log(t) * (a - 0.5d0))) - t
          else
              tmp = t_2
          end if
          code = tmp
      end function
      
      public static double code(double x, double y, double z, double t, double a) {
      	double t_1 = Math.log(z) + Math.log((y + x));
      	double t_2 = ((Math.log(t) * a) + Math.log(y)) - t;
      	double tmp;
      	if (t_1 <= -750.0) {
      		tmp = t_2;
      	} else if (t_1 <= 720.0) {
      		tmp = (Math.log((z * y)) + (Math.log(t) * (a - 0.5))) - t;
      	} else {
      		tmp = t_2;
      	}
      	return tmp;
      }
      
      def code(x, y, z, t, a):
      	t_1 = math.log(z) + math.log((y + x))
      	t_2 = ((math.log(t) * a) + math.log(y)) - t
      	tmp = 0
      	if t_1 <= -750.0:
      		tmp = t_2
      	elif t_1 <= 720.0:
      		tmp = (math.log((z * y)) + (math.log(t) * (a - 0.5))) - t
      	else:
      		tmp = t_2
      	return tmp
      
      function code(x, y, z, t, a)
      	t_1 = Float64(log(z) + log(Float64(y + x)))
      	t_2 = Float64(Float64(Float64(log(t) * a) + log(y)) - t)
      	tmp = 0.0
      	if (t_1 <= -750.0)
      		tmp = t_2;
      	elseif (t_1 <= 720.0)
      		tmp = Float64(Float64(log(Float64(z * y)) + Float64(log(t) * Float64(a - 0.5))) - t);
      	else
      		tmp = t_2;
      	end
      	return tmp
      end
      
      function tmp_2 = code(x, y, z, t, a)
      	t_1 = log(z) + log((y + x));
      	t_2 = ((log(t) * a) + log(y)) - t;
      	tmp = 0.0;
      	if (t_1 <= -750.0)
      		tmp = t_2;
      	elseif (t_1 <= 720.0)
      		tmp = (log((z * y)) + (log(t) * (a - 0.5))) - t;
      	else
      		tmp = t_2;
      	end
      	tmp_2 = tmp;
      end
      
      code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[Log[z], $MachinePrecision] + N[Log[N[(y + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]}, If[LessEqual[t$95$1, -750.0], t$95$2, If[LessEqual[t$95$1, 720.0], N[(N[(N[Log[N[(z * y), $MachinePrecision]], $MachinePrecision] + N[(N[Log[t], $MachinePrecision] * N[(a - 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision], t$95$2]]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      t_1 := \log z + \log \left(y + x\right)\\
      t_2 := \left(\log t \cdot a + \log y\right) - t\\
      \mathbf{if}\;t\_1 \leq -750:\\
      \;\;\;\;t\_2\\
      
      \mathbf{elif}\;t\_1 \leq 720:\\
      \;\;\;\;\left(\log \left(z \cdot y\right) + \log t \cdot \left(a - 0.5\right)\right) - t\\
      
      \mathbf{else}:\\
      \;\;\;\;t\_2\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < -750 or 720 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 z))

        1. Initial program 99.8%

          \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
        2. Add Preprocessing
        3. Taylor expanded in y around inf

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

            \[\leadsto \color{blue}{\left(\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right)} - t \]
          2. associate--l+N/A

            \[\leadsto \color{blue}{\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right)} \]
          3. +-commutativeN/A

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

            \[\leadsto \left(\color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{1}{y}\right)\right)\right)} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
          5. log-recN/A

            \[\leadsto \left(\left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(\log y\right)\right)}\right)\right) + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
          6. remove-double-negN/A

            \[\leadsto \left(\color{blue}{\log y} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
          7. associate--l+N/A

            \[\leadsto \color{blue}{\left(\left(\log y + \log z\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right) - t} \]
          8. associate-+r+N/A

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

            \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
        5. Applied rewrites58.0%

          \[\leadsto \color{blue}{\left(\log y + \mathsf{fma}\left(a - 0.5, \log t, \log z\right)\right) - t} \]
        6. Taylor expanded in a around inf

          \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
        7. Step-by-step derivation
          1. Applied rewrites44.9%

            \[\leadsto \left(\log y + a \cdot \log t\right) - t \]

          if -750 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < 720

          1. Initial program 99.6%

            \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
          2. Add Preprocessing
          3. Taylor expanded in y around inf

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

              \[\leadsto \color{blue}{\left(\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right)} - t \]
            2. associate--l+N/A

              \[\leadsto \color{blue}{\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right)} \]
            3. +-commutativeN/A

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

              \[\leadsto \left(\color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{1}{y}\right)\right)\right)} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
            5. log-recN/A

              \[\leadsto \left(\left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(\log y\right)\right)}\right)\right) + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
            6. remove-double-negN/A

              \[\leadsto \left(\color{blue}{\log y} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
            7. associate--l+N/A

              \[\leadsto \color{blue}{\left(\left(\log y + \log z\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right) - t} \]
            8. associate-+r+N/A

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

              \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
          5. Applied rewrites64.5%

            \[\leadsto \color{blue}{\left(\log y + \mathsf{fma}\left(a - 0.5, \log t, \log z\right)\right) - t} \]
          6. Step-by-step derivation
            1. Applied rewrites61.7%

              \[\leadsto \left(\log t \cdot \left(a - 0.5\right) + \log \left(z \cdot y\right)\right) - t \]
          7. Recombined 2 regimes into one program.
          8. Final simplification56.7%

            \[\leadsto \begin{array}{l} \mathbf{if}\;\log z + \log \left(y + x\right) \leq -750:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \mathbf{elif}\;\log z + \log \left(y + x\right) \leq 720:\\ \;\;\;\;\left(\log \left(z \cdot y\right) + \log t \cdot \left(a - 0.5\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \end{array} \]
          9. Add Preprocessing

          Alternative 5: 64.0% accurate, 0.5× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} t_1 := \log z + \log \left(y + x\right)\\ t_2 := \left(\log t \cdot a + \log y\right) - t\\ \mathbf{if}\;t\_1 \leq -750:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq 720:\\ \;\;\;\;\mathsf{fma}\left(a - 0.5, \log t, \log \left(z \cdot y\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \end{array} \]
          (FPCore (x y z t a)
           :precision binary64
           (let* ((t_1 (+ (log z) (log (+ y x)))) (t_2 (- (+ (* (log t) a) (log y)) t)))
             (if (<= t_1 -750.0)
               t_2
               (if (<= t_1 720.0) (- (fma (- a 0.5) (log t) (log (* z y))) t) t_2))))
          double code(double x, double y, double z, double t, double a) {
          	double t_1 = log(z) + log((y + x));
          	double t_2 = ((log(t) * a) + log(y)) - t;
          	double tmp;
          	if (t_1 <= -750.0) {
          		tmp = t_2;
          	} else if (t_1 <= 720.0) {
          		tmp = fma((a - 0.5), log(t), log((z * y))) - t;
          	} else {
          		tmp = t_2;
          	}
          	return tmp;
          }
          
          function code(x, y, z, t, a)
          	t_1 = Float64(log(z) + log(Float64(y + x)))
          	t_2 = Float64(Float64(Float64(log(t) * a) + log(y)) - t)
          	tmp = 0.0
          	if (t_1 <= -750.0)
          		tmp = t_2;
          	elseif (t_1 <= 720.0)
          		tmp = Float64(fma(Float64(a - 0.5), log(t), log(Float64(z * y))) - t);
          	else
          		tmp = t_2;
          	end
          	return tmp
          end
          
          code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[Log[z], $MachinePrecision] + N[Log[N[(y + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]}, If[LessEqual[t$95$1, -750.0], t$95$2, If[LessEqual[t$95$1, 720.0], N[(N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision] + N[Log[N[(z * y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision], t$95$2]]]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          t_1 := \log z + \log \left(y + x\right)\\
          t_2 := \left(\log t \cdot a + \log y\right) - t\\
          \mathbf{if}\;t\_1 \leq -750:\\
          \;\;\;\;t\_2\\
          
          \mathbf{elif}\;t\_1 \leq 720:\\
          \;\;\;\;\mathsf{fma}\left(a - 0.5, \log t, \log \left(z \cdot y\right)\right) - t\\
          
          \mathbf{else}:\\
          \;\;\;\;t\_2\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < -750 or 720 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 z))

            1. Initial program 99.8%

              \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
            2. Add Preprocessing
            3. Taylor expanded in y around inf

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

                \[\leadsto \color{blue}{\left(\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right)} - t \]
              2. associate--l+N/A

                \[\leadsto \color{blue}{\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right)} \]
              3. +-commutativeN/A

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

                \[\leadsto \left(\color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{1}{y}\right)\right)\right)} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
              5. log-recN/A

                \[\leadsto \left(\left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(\log y\right)\right)}\right)\right) + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
              6. remove-double-negN/A

                \[\leadsto \left(\color{blue}{\log y} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
              7. associate--l+N/A

                \[\leadsto \color{blue}{\left(\left(\log y + \log z\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right) - t} \]
              8. associate-+r+N/A

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

                \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
            5. Applied rewrites58.0%

              \[\leadsto \color{blue}{\left(\log y + \mathsf{fma}\left(a - 0.5, \log t, \log z\right)\right) - t} \]
            6. Taylor expanded in a around inf

              \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
            7. Step-by-step derivation
              1. Applied rewrites44.9%

                \[\leadsto \left(\log y + a \cdot \log t\right) - t \]

              if -750 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < 720

              1. Initial program 99.6%

                \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
              2. Add Preprocessing
              3. Step-by-step derivation
                1. lift-+.f64N/A

                  \[\leadsto \color{blue}{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - \frac{1}{2}\right) \cdot \log t} \]
                2. flip-+N/A

                  \[\leadsto \color{blue}{\frac{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) \cdot \left(\left(\log \left(x + y\right) + \log z\right) - t\right) - \left(\left(a - \frac{1}{2}\right) \cdot \log t\right) \cdot \left(\left(a - \frac{1}{2}\right) \cdot \log t\right)}{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) - \left(a - \frac{1}{2}\right) \cdot \log t}} \]
                3. clear-numN/A

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

                  \[\leadsto \color{blue}{\frac{1}{\frac{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) - \left(a - \frac{1}{2}\right) \cdot \log t}{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) \cdot \left(\left(\log \left(x + y\right) + \log z\right) - t\right) - \left(\left(a - \frac{1}{2}\right) \cdot \log t\right) \cdot \left(\left(a - \frac{1}{2}\right) \cdot \log t\right)}}} \]
                5. clear-numN/A

                  \[\leadsto \frac{1}{\color{blue}{\frac{1}{\frac{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) \cdot \left(\left(\log \left(x + y\right) + \log z\right) - t\right) - \left(\left(a - \frac{1}{2}\right) \cdot \log t\right) \cdot \left(\left(a - \frac{1}{2}\right) \cdot \log t\right)}{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) - \left(a - \frac{1}{2}\right) \cdot \log t}}}} \]
              4. Applied rewrites99.3%

                \[\leadsto \color{blue}{\frac{1}{\frac{1}{\mathsf{fma}\left(\log t, a - 0.5, \log \left(z \cdot \left(y + x\right)\right) - t\right)}}} \]
              5. Taylor expanded in x around 0

                \[\leadsto \color{blue}{\left(\log \left(y \cdot z\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right) - t} \]
              6. Step-by-step derivation
                1. lower--.f64N/A

                  \[\leadsto \color{blue}{\left(\log \left(y \cdot z\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right) - t} \]
                2. +-commutativeN/A

                  \[\leadsto \color{blue}{\left(\log t \cdot \left(a - \frac{1}{2}\right) + \log \left(y \cdot z\right)\right)} - t \]
                3. *-commutativeN/A

                  \[\leadsto \left(\color{blue}{\left(a - \frac{1}{2}\right) \cdot \log t} + \log \left(y \cdot z\right)\right) - t \]
                4. lower-fma.f64N/A

                  \[\leadsto \color{blue}{\mathsf{fma}\left(a - \frac{1}{2}, \log t, \log \left(y \cdot z\right)\right)} - t \]
                5. lower--.f64N/A

                  \[\leadsto \mathsf{fma}\left(\color{blue}{a - \frac{1}{2}}, \log t, \log \left(y \cdot z\right)\right) - t \]
                6. lower-log.f64N/A

                  \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \color{blue}{\log t}, \log \left(y \cdot z\right)\right) - t \]
                7. lower-log.f64N/A

                  \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \log t, \color{blue}{\log \left(y \cdot z\right)}\right) - t \]
                8. lower-*.f6461.7

                  \[\leadsto \mathsf{fma}\left(a - 0.5, \log t, \log \color{blue}{\left(y \cdot z\right)}\right) - t \]
              7. Applied rewrites61.7%

                \[\leadsto \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(y \cdot z\right)\right) - t} \]
            8. Recombined 2 regimes into one program.
            9. Final simplification56.7%

              \[\leadsto \begin{array}{l} \mathbf{if}\;\log z + \log \left(y + x\right) \leq -750:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \mathbf{elif}\;\log z + \log \left(y + x\right) \leq 720:\\ \;\;\;\;\mathsf{fma}\left(a - 0.5, \log t, \log \left(z \cdot y\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \end{array} \]
            10. Add Preprocessing

            Alternative 6: 80.5% accurate, 1.0× speedup?

            \[\begin{array}{l} \\ \begin{array}{l} t_1 := \log t \cdot a - t\\ \mathbf{if}\;a - 0.5 \leq -500000:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;a - 0.5 \leq -0.498:\\ \;\;\;\;\left(\mathsf{fma}\left(\log t, -0.5, \log z\right) - t\right) + \log y\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
            (FPCore (x y z t a)
             :precision binary64
             (let* ((t_1 (- (* (log t) a) t)))
               (if (<= (- a 0.5) -500000.0)
                 t_1
                 (if (<= (- a 0.5) -0.498)
                   (+ (- (fma (log t) -0.5 (log z)) t) (log y))
                   t_1))))
            double code(double x, double y, double z, double t, double a) {
            	double t_1 = (log(t) * a) - t;
            	double tmp;
            	if ((a - 0.5) <= -500000.0) {
            		tmp = t_1;
            	} else if ((a - 0.5) <= -0.498) {
            		tmp = (fma(log(t), -0.5, log(z)) - t) + log(y);
            	} else {
            		tmp = t_1;
            	}
            	return tmp;
            }
            
            function code(x, y, z, t, a)
            	t_1 = Float64(Float64(log(t) * a) - t)
            	tmp = 0.0
            	if (Float64(a - 0.5) <= -500000.0)
            		tmp = t_1;
            	elseif (Float64(a - 0.5) <= -0.498)
            		tmp = Float64(Float64(fma(log(t), -0.5, log(z)) - t) + log(y));
            	else
            		tmp = t_1;
            	end
            	return tmp
            end
            
            code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] - t), $MachinePrecision]}, If[LessEqual[N[(a - 0.5), $MachinePrecision], -500000.0], t$95$1, If[LessEqual[N[(a - 0.5), $MachinePrecision], -0.498], N[(N[(N[(N[Log[t], $MachinePrecision] * -0.5 + N[Log[z], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision], t$95$1]]]
            
            \begin{array}{l}
            
            \\
            \begin{array}{l}
            t_1 := \log t \cdot a - t\\
            \mathbf{if}\;a - 0.5 \leq -500000:\\
            \;\;\;\;t\_1\\
            
            \mathbf{elif}\;a - 0.5 \leq -0.498:\\
            \;\;\;\;\left(\mathsf{fma}\left(\log t, -0.5, \log z\right) - t\right) + \log y\\
            
            \mathbf{else}:\\
            \;\;\;\;t\_1\\
            
            
            \end{array}
            \end{array}
            
            Derivation
            1. Split input into 2 regimes
            2. if (-.f64 a #s(literal 1/2 binary64)) < -5e5 or -0.498 < (-.f64 a #s(literal 1/2 binary64))

              1. Initial program 99.7%

                \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
              2. Add Preprocessing
              3. Taylor expanded in y around inf

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

                  \[\leadsto \color{blue}{\left(\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right)} - t \]
                2. associate--l+N/A

                  \[\leadsto \color{blue}{\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right)} \]
                3. +-commutativeN/A

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

                  \[\leadsto \left(\color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{1}{y}\right)\right)\right)} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                5. log-recN/A

                  \[\leadsto \left(\left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(\log y\right)\right)}\right)\right) + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                6. remove-double-negN/A

                  \[\leadsto \left(\color{blue}{\log y} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                7. associate--l+N/A

                  \[\leadsto \color{blue}{\left(\left(\log y + \log z\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right) - t} \]
                8. associate-+r+N/A

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

                  \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
              5. Applied rewrites66.9%

                \[\leadsto \color{blue}{\left(\log y + \mathsf{fma}\left(a - 0.5, \log t, \log z\right)\right) - t} \]
              6. Taylor expanded in a around inf

                \[\leadsto a \cdot \log t - t \]
              7. Step-by-step derivation
                1. Applied rewrites99.0%

                  \[\leadsto a \cdot \log t - t \]

                if -5e5 < (-.f64 a #s(literal 1/2 binary64)) < -0.498

                1. Initial program 99.5%

                  \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
                2. Add Preprocessing
                3. Taylor expanded in y around inf

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

                    \[\leadsto \color{blue}{\left(\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right)} - t \]
                  2. associate--l+N/A

                    \[\leadsto \color{blue}{\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right)} \]
                  3. +-commutativeN/A

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

                    \[\leadsto \left(\color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{1}{y}\right)\right)\right)} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                  5. log-recN/A

                    \[\leadsto \left(\left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(\log y\right)\right)}\right)\right) + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                  6. remove-double-negN/A

                    \[\leadsto \left(\color{blue}{\log y} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                  7. associate--l+N/A

                    \[\leadsto \color{blue}{\left(\left(\log y + \log z\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right) - t} \]
                  8. associate-+r+N/A

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

                    \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                5. Applied rewrites58.2%

                  \[\leadsto \color{blue}{\left(\log y + \mathsf{fma}\left(a - 0.5, \log t, \log z\right)\right) - t} \]
                6. Taylor expanded in a around 0

                  \[\leadsto \left(\log y + \left(\log z + \frac{-1}{2} \cdot \log t\right)\right) - \color{blue}{t} \]
                7. Step-by-step derivation
                  1. Applied rewrites57.9%

                    \[\leadsto \log y + \color{blue}{\left(\mathsf{fma}\left(\log t, -0.5, \log z\right) - t\right)} \]
                8. Recombined 2 regimes into one program.
                9. Final simplification78.5%

                  \[\leadsto \begin{array}{l} \mathbf{if}\;a - 0.5 \leq -500000:\\ \;\;\;\;\log t \cdot a - t\\ \mathbf{elif}\;a - 0.5 \leq -0.498:\\ \;\;\;\;\left(\mathsf{fma}\left(\log t, -0.5, \log z\right) - t\right) + \log y\\ \mathbf{else}:\\ \;\;\;\;\log t \cdot a - t\\ \end{array} \]
                10. Add Preprocessing

                Alternative 7: 68.5% accurate, 1.0× speedup?

                \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq 135:\\ \;\;\;\;\mathsf{fma}\left(a - 0.5, \log t, \log z\right) + \log y\\ \mathbf{else}:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \end{array} \end{array} \]
                (FPCore (x y z t a)
                 :precision binary64
                 (if (<= t 135.0)
                   (+ (fma (- a 0.5) (log t) (log z)) (log y))
                   (- (+ (* (log t) a) (log y)) t)))
                double code(double x, double y, double z, double t, double a) {
                	double tmp;
                	if (t <= 135.0) {
                		tmp = fma((a - 0.5), log(t), log(z)) + log(y);
                	} else {
                		tmp = ((log(t) * a) + log(y)) - t;
                	}
                	return tmp;
                }
                
                function code(x, y, z, t, a)
                	tmp = 0.0
                	if (t <= 135.0)
                		tmp = Float64(fma(Float64(a - 0.5), log(t), log(z)) + log(y));
                	else
                		tmp = Float64(Float64(Float64(log(t) * a) + log(y)) - t);
                	end
                	return tmp
                end
                
                code[x_, y_, z_, t_, a_] := If[LessEqual[t, 135.0], N[(N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]]
                
                \begin{array}{l}
                
                \\
                \begin{array}{l}
                \mathbf{if}\;t \leq 135:\\
                \;\;\;\;\mathsf{fma}\left(a - 0.5, \log t, \log z\right) + \log y\\
                
                \mathbf{else}:\\
                \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\
                
                
                \end{array}
                \end{array}
                
                Derivation
                1. Split input into 2 regimes
                2. if t < 135

                  1. Initial program 99.4%

                    \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
                  2. Add Preprocessing
                  3. Taylor expanded in y around inf

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

                      \[\leadsto \color{blue}{\left(\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right)} - t \]
                    2. associate--l+N/A

                      \[\leadsto \color{blue}{\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right)} \]
                    3. +-commutativeN/A

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

                      \[\leadsto \left(\color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{1}{y}\right)\right)\right)} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                    5. log-recN/A

                      \[\leadsto \left(\left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(\log y\right)\right)}\right)\right) + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                    6. remove-double-negN/A

                      \[\leadsto \left(\color{blue}{\log y} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                    7. associate--l+N/A

                      \[\leadsto \color{blue}{\left(\left(\log y + \log z\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right) - t} \]
                    8. associate-+r+N/A

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

                      \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                  5. Applied rewrites61.6%

                    \[\leadsto \color{blue}{\left(\log y + \mathsf{fma}\left(a - 0.5, \log t, \log z\right)\right) - t} \]
                  6. Taylor expanded in t around 0

                    \[\leadsto \log y + \color{blue}{\left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)} \]
                  7. Step-by-step derivation
                    1. Applied rewrites60.9%

                      \[\leadsto \mathsf{fma}\left(a - 0.5, \log t, \log z\right) + \color{blue}{\log y} \]

                    if 135 < t

                    1. Initial program 99.9%

                      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
                    2. Add Preprocessing
                    3. Taylor expanded in y around inf

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

                        \[\leadsto \color{blue}{\left(\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right)} - t \]
                      2. associate--l+N/A

                        \[\leadsto \color{blue}{\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right)} \]
                      3. +-commutativeN/A

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

                        \[\leadsto \left(\color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{1}{y}\right)\right)\right)} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                      5. log-recN/A

                        \[\leadsto \left(\left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(\log y\right)\right)}\right)\right) + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                      6. remove-double-negN/A

                        \[\leadsto \left(\color{blue}{\log y} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                      7. associate--l+N/A

                        \[\leadsto \color{blue}{\left(\left(\log y + \log z\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right) - t} \]
                      8. associate-+r+N/A

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

                        \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                    5. Applied rewrites63.6%

                      \[\leadsto \color{blue}{\left(\log y + \mathsf{fma}\left(a - 0.5, \log t, \log z\right)\right) - t} \]
                    6. Taylor expanded in a around inf

                      \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
                    7. Step-by-step derivation
                      1. Applied rewrites62.3%

                        \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
                    8. Recombined 2 regimes into one program.
                    9. Final simplification61.5%

                      \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq 135:\\ \;\;\;\;\mathsf{fma}\left(a - 0.5, \log t, \log z\right) + \log y\\ \mathbf{else}:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \end{array} \]
                    10. Add Preprocessing

                    Alternative 8: 68.9% accurate, 1.0× speedup?

                    \[\begin{array}{l} \\ \left(\log z - t\right) + \mathsf{fma}\left(-0.5 + a, \log t, \log y\right) \end{array} \]
                    (FPCore (x y z t a)
                     :precision binary64
                     (+ (- (log z) t) (fma (+ -0.5 a) (log t) (log y))))
                    double code(double x, double y, double z, double t, double a) {
                    	return (log(z) - t) + fma((-0.5 + a), log(t), log(y));
                    }
                    
                    function code(x, y, z, t, a)
                    	return Float64(Float64(log(z) - t) + fma(Float64(-0.5 + a), log(t), log(y)))
                    end
                    
                    code[x_, y_, z_, t_, a_] := N[(N[(N[Log[z], $MachinePrecision] - t), $MachinePrecision] + N[(N[(-0.5 + a), $MachinePrecision] * N[Log[t], $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
                    
                    \begin{array}{l}
                    
                    \\
                    \left(\log z - t\right) + \mathsf{fma}\left(-0.5 + a, \log t, \log y\right)
                    \end{array}
                    
                    Derivation
                    1. Initial program 99.6%

                      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
                    2. Add Preprocessing
                    3. Step-by-step derivation
                      1. lift-+.f64N/A

                        \[\leadsto \color{blue}{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - \frac{1}{2}\right) \cdot \log t} \]
                      2. flip-+N/A

                        \[\leadsto \color{blue}{\frac{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) \cdot \left(\left(\log \left(x + y\right) + \log z\right) - t\right) - \left(\left(a - \frac{1}{2}\right) \cdot \log t\right) \cdot \left(\left(a - \frac{1}{2}\right) \cdot \log t\right)}{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) - \left(a - \frac{1}{2}\right) \cdot \log t}} \]
                      3. clear-numN/A

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

                        \[\leadsto \color{blue}{\frac{1}{\frac{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) - \left(a - \frac{1}{2}\right) \cdot \log t}{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) \cdot \left(\left(\log \left(x + y\right) + \log z\right) - t\right) - \left(\left(a - \frac{1}{2}\right) \cdot \log t\right) \cdot \left(\left(a - \frac{1}{2}\right) \cdot \log t\right)}}} \]
                      5. clear-numN/A

                        \[\leadsto \frac{1}{\color{blue}{\frac{1}{\frac{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) \cdot \left(\left(\log \left(x + y\right) + \log z\right) - t\right) - \left(\left(a - \frac{1}{2}\right) \cdot \log t\right) \cdot \left(\left(a - \frac{1}{2}\right) \cdot \log t\right)}{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) - \left(a - \frac{1}{2}\right) \cdot \log t}}}} \]
                    4. Applied rewrites70.5%

                      \[\leadsto \color{blue}{\frac{1}{\frac{1}{\mathsf{fma}\left(\log t, a - 0.5, \log \left(z \cdot \left(y + x\right)\right) - t\right)}}} \]
                    5. Taylor expanded in y around 0

                      \[\leadsto \color{blue}{\left(\log \left(x \cdot z\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right) - t} \]
                    6. Step-by-step derivation
                      1. lower--.f64N/A

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

                        \[\leadsto \color{blue}{\left(\log t \cdot \left(a - \frac{1}{2}\right) + \log \left(x \cdot z\right)\right)} - t \]
                      3. *-commutativeN/A

                        \[\leadsto \left(\color{blue}{\left(a - \frac{1}{2}\right) \cdot \log t} + \log \left(x \cdot z\right)\right) - t \]
                      4. lower-fma.f64N/A

                        \[\leadsto \color{blue}{\mathsf{fma}\left(a - \frac{1}{2}, \log t, \log \left(x \cdot z\right)\right)} - t \]
                      5. lower--.f64N/A

                        \[\leadsto \mathsf{fma}\left(\color{blue}{a - \frac{1}{2}}, \log t, \log \left(x \cdot z\right)\right) - t \]
                      6. lower-log.f64N/A

                        \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \color{blue}{\log t}, \log \left(x \cdot z\right)\right) - t \]
                      7. lower-log.f64N/A

                        \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \log t, \color{blue}{\log \left(x \cdot z\right)}\right) - t \]
                      8. lower-*.f6448.9

                        \[\leadsto \mathsf{fma}\left(a - 0.5, \log t, \log \color{blue}{\left(x \cdot z\right)}\right) - t \]
                    7. Applied rewrites48.9%

                      \[\leadsto \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(x \cdot z\right)\right) - t} \]
                    8. Taylor expanded in t around inf

                      \[\leadsto \color{blue}{t \cdot \left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \frac{\log \left(z \cdot \left(x + y\right)\right)}{t}\right) - 1\right)} \]
                    9. Step-by-step derivation
                      1. *-commutativeN/A

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

                        \[\leadsto \color{blue}{\left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \frac{\log \left(z \cdot \left(x + y\right)\right)}{t}\right) - 1\right) \cdot t} \]
                    10. Applied rewrites63.6%

                      \[\leadsto \color{blue}{\left(\mathsf{fma}\left(\log t, \frac{a - 0.5}{t}, \frac{\log \left(\left(y + x\right) \cdot z\right)}{t}\right) - 1\right) \cdot t} \]
                    11. Taylor expanded in y around inf

                      \[\leadsto \color{blue}{\left(\log z + \left(-1 \cdot \log \left(\frac{1}{y}\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                    12. Step-by-step derivation
                      1. +-commutativeN/A

                        \[\leadsto \color{blue}{\left(\left(-1 \cdot \log \left(\frac{1}{y}\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right) + \log z\right)} - t \]
                      2. associate--l+N/A

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

                        \[\leadsto \color{blue}{\left(-1 \cdot \log \left(\frac{1}{y}\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right) + \left(\log z - t\right)} \]
                      4. +-commutativeN/A

                        \[\leadsto \color{blue}{\left(\log t \cdot \left(a - \frac{1}{2}\right) + -1 \cdot \log \left(\frac{1}{y}\right)\right)} + \left(\log z - t\right) \]
                      5. sub-negN/A

                        \[\leadsto \left(\log t \cdot \color{blue}{\left(a + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)\right)} + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \left(\log z - t\right) \]
                      6. metadata-evalN/A

                        \[\leadsto \left(\log t \cdot \left(a + \color{blue}{\frac{-1}{2}}\right) + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \left(\log z - t\right) \]
                      7. distribute-rgt-inN/A

                        \[\leadsto \left(\color{blue}{\left(a \cdot \log t + \frac{-1}{2} \cdot \log t\right)} + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \left(\log z - t\right) \]
                      8. +-commutativeN/A

                        \[\leadsto \left(\color{blue}{\left(\frac{-1}{2} \cdot \log t + a \cdot \log t\right)} + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \left(\log z - t\right) \]
                      9. distribute-rgt-outN/A

                        \[\leadsto \left(\color{blue}{\log t \cdot \left(\frac{-1}{2} + a\right)} + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \left(\log z - t\right) \]
                      10. *-commutativeN/A

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

                        \[\leadsto \left(\left(\frac{-1}{2} + a\right) \cdot \log t + \color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{1}{y}\right)\right)\right)}\right) + \left(\log z - t\right) \]
                      12. log-recN/A

                        \[\leadsto \left(\left(\frac{-1}{2} + a\right) \cdot \log t + \left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(\log y\right)\right)}\right)\right)\right) + \left(\log z - t\right) \]
                      13. remove-double-negN/A

                        \[\leadsto \left(\left(\frac{-1}{2} + a\right) \cdot \log t + \color{blue}{\log y}\right) + \left(\log z - t\right) \]
                      14. lower-fma.f64N/A

                        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{-1}{2} + a, \log t, \log y\right)} + \left(\log z - t\right) \]
                      15. lower-+.f64N/A

                        \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{-1}{2} + a}, \log t, \log y\right) + \left(\log z - t\right) \]
                      16. lower-log.f64N/A

                        \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \color{blue}{\log t}, \log y\right) + \left(\log z - t\right) \]
                      17. lower-log.f64N/A

                        \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \log t, \color{blue}{\log y}\right) + \left(\log z - t\right) \]
                      18. lower--.f64N/A

                        \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \log t, \log y\right) + \color{blue}{\left(\log z - t\right)} \]
                      19. lower-log.f6462.5

                        \[\leadsto \mathsf{fma}\left(-0.5 + a, \log t, \log y\right) + \left(\color{blue}{\log z} - t\right) \]
                    13. Applied rewrites62.5%

                      \[\leadsto \color{blue}{\mathsf{fma}\left(-0.5 + a, \log t, \log y\right) + \left(\log z - t\right)} \]
                    14. Final simplification62.5%

                      \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(-0.5 + a, \log t, \log y\right) \]
                    15. Add Preprocessing

                    Alternative 9: 69.0% accurate, 1.0× speedup?

                    \[\begin{array}{l} \\ \left(\mathsf{fma}\left(a - 0.5, \log t, \log z\right) + \log y\right) - t \end{array} \]
                    (FPCore (x y z t a)
                     :precision binary64
                     (- (+ (fma (- a 0.5) (log t) (log z)) (log y)) t))
                    double code(double x, double y, double z, double t, double a) {
                    	return (fma((a - 0.5), log(t), log(z)) + log(y)) - t;
                    }
                    
                    function code(x, y, z, t, a)
                    	return Float64(Float64(fma(Float64(a - 0.5), log(t), log(z)) + log(y)) - t)
                    end
                    
                    code[x_, y_, z_, t_, a_] := N[(N[(N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]
                    
                    \begin{array}{l}
                    
                    \\
                    \left(\mathsf{fma}\left(a - 0.5, \log t, \log z\right) + \log y\right) - t
                    \end{array}
                    
                    Derivation
                    1. Initial program 99.6%

                      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
                    2. Add Preprocessing
                    3. Taylor expanded in y around inf

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

                        \[\leadsto \color{blue}{\left(\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right)} - t \]
                      2. associate--l+N/A

                        \[\leadsto \color{blue}{\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right)} \]
                      3. +-commutativeN/A

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

                        \[\leadsto \left(\color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{1}{y}\right)\right)\right)} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                      5. log-recN/A

                        \[\leadsto \left(\left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(\log y\right)\right)}\right)\right) + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                      6. remove-double-negN/A

                        \[\leadsto \left(\color{blue}{\log y} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                      7. associate--l+N/A

                        \[\leadsto \color{blue}{\left(\left(\log y + \log z\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right) - t} \]
                      8. associate-+r+N/A

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

                        \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                    5. Applied rewrites62.6%

                      \[\leadsto \color{blue}{\left(\log y + \mathsf{fma}\left(a - 0.5, \log t, \log z\right)\right) - t} \]
                    6. Final simplification62.6%

                      \[\leadsto \left(\mathsf{fma}\left(a - 0.5, \log t, \log z\right) + \log y\right) - t \]
                    7. Add Preprocessing

                    Alternative 10: 58.6% accurate, 1.5× speedup?

                    \[\begin{array}{l} \\ \left(\log t \cdot a + \log y\right) - t \end{array} \]
                    (FPCore (x y z t a) :precision binary64 (- (+ (* (log t) a) (log y)) t))
                    double code(double x, double y, double z, double t, double a) {
                    	return ((log(t) * a) + log(y)) - t;
                    }
                    
                    real(8) function code(x, y, z, t, a)
                        real(8), intent (in) :: x
                        real(8), intent (in) :: y
                        real(8), intent (in) :: z
                        real(8), intent (in) :: t
                        real(8), intent (in) :: a
                        code = ((log(t) * a) + log(y)) - t
                    end function
                    
                    public static double code(double x, double y, double z, double t, double a) {
                    	return ((Math.log(t) * a) + Math.log(y)) - t;
                    }
                    
                    def code(x, y, z, t, a):
                    	return ((math.log(t) * a) + math.log(y)) - t
                    
                    function code(x, y, z, t, a)
                    	return Float64(Float64(Float64(log(t) * a) + log(y)) - t)
                    end
                    
                    function tmp = code(x, y, z, t, a)
                    	tmp = ((log(t) * a) + log(y)) - t;
                    end
                    
                    code[x_, y_, z_, t_, a_] := N[(N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]
                    
                    \begin{array}{l}
                    
                    \\
                    \left(\log t \cdot a + \log y\right) - t
                    \end{array}
                    
                    Derivation
                    1. Initial program 99.6%

                      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
                    2. Add Preprocessing
                    3. Taylor expanded in y around inf

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

                        \[\leadsto \color{blue}{\left(\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right)} - t \]
                      2. associate--l+N/A

                        \[\leadsto \color{blue}{\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right)} \]
                      3. +-commutativeN/A

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

                        \[\leadsto \left(\color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{1}{y}\right)\right)\right)} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                      5. log-recN/A

                        \[\leadsto \left(\left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(\log y\right)\right)}\right)\right) + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                      6. remove-double-negN/A

                        \[\leadsto \left(\color{blue}{\log y} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                      7. associate--l+N/A

                        \[\leadsto \color{blue}{\left(\left(\log y + \log z\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right) - t} \]
                      8. associate-+r+N/A

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

                        \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                    5. Applied rewrites62.6%

                      \[\leadsto \color{blue}{\left(\log y + \mathsf{fma}\left(a - 0.5, \log t, \log z\right)\right) - t} \]
                    6. Taylor expanded in a around inf

                      \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
                    7. Step-by-step derivation
                      1. Applied rewrites51.5%

                        \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
                      2. Final simplification51.5%

                        \[\leadsto \left(\log t \cdot a + \log y\right) - t \]
                      3. Add Preprocessing

                      Alternative 11: 78.1% accurate, 2.8× speedup?

                      \[\begin{array}{l} \\ \left(-t\right) + \log t \cdot \left(a - 0.5\right) \end{array} \]
                      (FPCore (x y z t a) :precision binary64 (+ (- t) (* (log t) (- a 0.5))))
                      double code(double x, double y, double z, double t, double a) {
                      	return -t + (log(t) * (a - 0.5));
                      }
                      
                      real(8) function code(x, y, z, t, a)
                          real(8), intent (in) :: x
                          real(8), intent (in) :: y
                          real(8), intent (in) :: z
                          real(8), intent (in) :: t
                          real(8), intent (in) :: a
                          code = -t + (log(t) * (a - 0.5d0))
                      end function
                      
                      public static double code(double x, double y, double z, double t, double a) {
                      	return -t + (Math.log(t) * (a - 0.5));
                      }
                      
                      def code(x, y, z, t, a):
                      	return -t + (math.log(t) * (a - 0.5))
                      
                      function code(x, y, z, t, a)
                      	return Float64(Float64(-t) + Float64(log(t) * Float64(a - 0.5)))
                      end
                      
                      function tmp = code(x, y, z, t, a)
                      	tmp = -t + (log(t) * (a - 0.5));
                      end
                      
                      code[x_, y_, z_, t_, a_] := N[((-t) + N[(N[Log[t], $MachinePrecision] * N[(a - 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
                      
                      \begin{array}{l}
                      
                      \\
                      \left(-t\right) + \log t \cdot \left(a - 0.5\right)
                      \end{array}
                      
                      Derivation
                      1. Initial program 99.6%

                        \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
                      2. Add Preprocessing
                      3. Taylor expanded in t around inf

                        \[\leadsto \color{blue}{-1 \cdot t} + \left(a - \frac{1}{2}\right) \cdot \log t \]
                      4. Step-by-step derivation
                        1. mul-1-negN/A

                          \[\leadsto \color{blue}{\left(\mathsf{neg}\left(t\right)\right)} + \left(a - \frac{1}{2}\right) \cdot \log t \]
                        2. lower-neg.f6476.0

                          \[\leadsto \color{blue}{\left(-t\right)} + \left(a - 0.5\right) \cdot \log t \]
                      5. Applied rewrites76.0%

                        \[\leadsto \color{blue}{\left(-t\right)} + \left(a - 0.5\right) \cdot \log t \]
                      6. Final simplification76.0%

                        \[\leadsto \left(-t\right) + \log t \cdot \left(a - 0.5\right) \]
                      7. Add Preprocessing

                      Alternative 12: 62.2% accurate, 2.9× speedup?

                      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq 2.15 \cdot 10^{+58}:\\ \;\;\;\;\log t \cdot a\\ \mathbf{else}:\\ \;\;\;\;-t\\ \end{array} \end{array} \]
                      (FPCore (x y z t a)
                       :precision binary64
                       (if (<= t 2.15e+58) (* (log t) a) (- t)))
                      double code(double x, double y, double z, double t, double a) {
                      	double tmp;
                      	if (t <= 2.15e+58) {
                      		tmp = log(t) * a;
                      	} else {
                      		tmp = -t;
                      	}
                      	return tmp;
                      }
                      
                      real(8) function code(x, y, z, t, a)
                          real(8), intent (in) :: x
                          real(8), intent (in) :: y
                          real(8), intent (in) :: z
                          real(8), intent (in) :: t
                          real(8), intent (in) :: a
                          real(8) :: tmp
                          if (t <= 2.15d+58) then
                              tmp = log(t) * a
                          else
                              tmp = -t
                          end if
                          code = tmp
                      end function
                      
                      public static double code(double x, double y, double z, double t, double a) {
                      	double tmp;
                      	if (t <= 2.15e+58) {
                      		tmp = Math.log(t) * a;
                      	} else {
                      		tmp = -t;
                      	}
                      	return tmp;
                      }
                      
                      def code(x, y, z, t, a):
                      	tmp = 0
                      	if t <= 2.15e+58:
                      		tmp = math.log(t) * a
                      	else:
                      		tmp = -t
                      	return tmp
                      
                      function code(x, y, z, t, a)
                      	tmp = 0.0
                      	if (t <= 2.15e+58)
                      		tmp = Float64(log(t) * a);
                      	else
                      		tmp = Float64(-t);
                      	end
                      	return tmp
                      end
                      
                      function tmp_2 = code(x, y, z, t, a)
                      	tmp = 0.0;
                      	if (t <= 2.15e+58)
                      		tmp = log(t) * a;
                      	else
                      		tmp = -t;
                      	end
                      	tmp_2 = tmp;
                      end
                      
                      code[x_, y_, z_, t_, a_] := If[LessEqual[t, 2.15e+58], N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision], (-t)]
                      
                      \begin{array}{l}
                      
                      \\
                      \begin{array}{l}
                      \mathbf{if}\;t \leq 2.15 \cdot 10^{+58}:\\
                      \;\;\;\;\log t \cdot a\\
                      
                      \mathbf{else}:\\
                      \;\;\;\;-t\\
                      
                      
                      \end{array}
                      \end{array}
                      
                      Derivation
                      1. Split input into 2 regimes
                      2. if t < 2.14999999999999996e58

                        1. Initial program 99.4%

                          \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
                        2. Add Preprocessing
                        3. Taylor expanded in a around inf

                          \[\leadsto \color{blue}{a \cdot \log t} \]
                        4. Step-by-step derivation
                          1. lower-*.f64N/A

                            \[\leadsto \color{blue}{a \cdot \log t} \]
                          2. lower-log.f6451.3

                            \[\leadsto a \cdot \color{blue}{\log t} \]
                        5. Applied rewrites51.3%

                          \[\leadsto \color{blue}{a \cdot \log t} \]

                        if 2.14999999999999996e58 < t

                        1. Initial program 99.9%

                          \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
                        2. Add Preprocessing
                        3. Taylor expanded in t around inf

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

                            \[\leadsto \color{blue}{\mathsf{neg}\left(t\right)} \]
                          2. lower-neg.f6485.3

                            \[\leadsto \color{blue}{-t} \]
                        5. Applied rewrites85.3%

                          \[\leadsto \color{blue}{-t} \]
                      3. Recombined 2 regimes into one program.
                      4. Final simplification64.4%

                        \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq 2.15 \cdot 10^{+58}:\\ \;\;\;\;\log t \cdot a\\ \mathbf{else}:\\ \;\;\;\;-t\\ \end{array} \]
                      5. Add Preprocessing

                      Alternative 13: 75.6% accurate, 2.9× speedup?

                      \[\begin{array}{l} \\ \log t \cdot a - t \end{array} \]
                      (FPCore (x y z t a) :precision binary64 (- (* (log t) a) t))
                      double code(double x, double y, double z, double t, double a) {
                      	return (log(t) * a) - t;
                      }
                      
                      real(8) function code(x, y, z, t, a)
                          real(8), intent (in) :: x
                          real(8), intent (in) :: y
                          real(8), intent (in) :: z
                          real(8), intent (in) :: t
                          real(8), intent (in) :: a
                          code = (log(t) * a) - t
                      end function
                      
                      public static double code(double x, double y, double z, double t, double a) {
                      	return (Math.log(t) * a) - t;
                      }
                      
                      def code(x, y, z, t, a):
                      	return (math.log(t) * a) - t
                      
                      function code(x, y, z, t, a)
                      	return Float64(Float64(log(t) * a) - t)
                      end
                      
                      function tmp = code(x, y, z, t, a)
                      	tmp = (log(t) * a) - t;
                      end
                      
                      code[x_, y_, z_, t_, a_] := N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] - t), $MachinePrecision]
                      
                      \begin{array}{l}
                      
                      \\
                      \log t \cdot a - t
                      \end{array}
                      
                      Derivation
                      1. Initial program 99.6%

                        \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
                      2. Add Preprocessing
                      3. Taylor expanded in y around inf

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

                          \[\leadsto \color{blue}{\left(\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right)} - t \]
                        2. associate--l+N/A

                          \[\leadsto \color{blue}{\left(\log z + -1 \cdot \log \left(\frac{1}{y}\right)\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right)} \]
                        3. +-commutativeN/A

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

                          \[\leadsto \left(\color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{1}{y}\right)\right)\right)} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                        5. log-recN/A

                          \[\leadsto \left(\left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(\log y\right)\right)}\right)\right) + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                        6. remove-double-negN/A

                          \[\leadsto \left(\color{blue}{\log y} + \log z\right) + \left(\log t \cdot \left(a - \frac{1}{2}\right) - t\right) \]
                        7. associate--l+N/A

                          \[\leadsto \color{blue}{\left(\left(\log y + \log z\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right) - t} \]
                        8. associate-+r+N/A

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

                          \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                      5. Applied rewrites62.6%

                        \[\leadsto \color{blue}{\left(\log y + \mathsf{fma}\left(a - 0.5, \log t, \log z\right)\right) - t} \]
                      6. Taylor expanded in a around inf

                        \[\leadsto a \cdot \log t - t \]
                      7. Step-by-step derivation
                        1. Applied rewrites73.5%

                          \[\leadsto a \cdot \log t - t \]
                        2. Final simplification73.5%

                          \[\leadsto \log t \cdot a - t \]
                        3. Add Preprocessing

                        Alternative 14: 38.4% accurate, 107.0× speedup?

                        \[\begin{array}{l} \\ -t \end{array} \]
                        (FPCore (x y z t a) :precision binary64 (- t))
                        double code(double x, double y, double z, double t, double a) {
                        	return -t;
                        }
                        
                        real(8) function code(x, y, z, t, a)
                            real(8), intent (in) :: x
                            real(8), intent (in) :: y
                            real(8), intent (in) :: z
                            real(8), intent (in) :: t
                            real(8), intent (in) :: a
                            code = -t
                        end function
                        
                        public static double code(double x, double y, double z, double t, double a) {
                        	return -t;
                        }
                        
                        def code(x, y, z, t, a):
                        	return -t
                        
                        function code(x, y, z, t, a)
                        	return Float64(-t)
                        end
                        
                        function tmp = code(x, y, z, t, a)
                        	tmp = -t;
                        end
                        
                        code[x_, y_, z_, t_, a_] := (-t)
                        
                        \begin{array}{l}
                        
                        \\
                        -t
                        \end{array}
                        
                        Derivation
                        1. Initial program 99.6%

                          \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
                        2. Add Preprocessing
                        3. Taylor expanded in t around inf

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

                            \[\leadsto \color{blue}{\mathsf{neg}\left(t\right)} \]
                          2. lower-neg.f6438.1

                            \[\leadsto \color{blue}{-t} \]
                        5. Applied rewrites38.1%

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

                        Alternative 15: 2.4% accurate, 321.0× speedup?

                        \[\begin{array}{l} \\ t \end{array} \]
                        (FPCore (x y z t a) :precision binary64 t)
                        double code(double x, double y, double z, double t, double a) {
                        	return t;
                        }
                        
                        real(8) function code(x, y, z, t, a)
                            real(8), intent (in) :: x
                            real(8), intent (in) :: y
                            real(8), intent (in) :: z
                            real(8), intent (in) :: t
                            real(8), intent (in) :: a
                            code = t
                        end function
                        
                        public static double code(double x, double y, double z, double t, double a) {
                        	return t;
                        }
                        
                        def code(x, y, z, t, a):
                        	return t
                        
                        function code(x, y, z, t, a)
                        	return t
                        end
                        
                        function tmp = code(x, y, z, t, a)
                        	tmp = t;
                        end
                        
                        code[x_, y_, z_, t_, a_] := t
                        
                        \begin{array}{l}
                        
                        \\
                        t
                        \end{array}
                        
                        Derivation
                        1. Initial program 99.6%

                          \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
                        2. Add Preprocessing
                        3. Taylor expanded in t around inf

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

                            \[\leadsto \color{blue}{\mathsf{neg}\left(t\right)} \]
                          2. lower-neg.f6438.1

                            \[\leadsto \color{blue}{-t} \]
                        5. Applied rewrites38.1%

                          \[\leadsto \color{blue}{-t} \]
                        6. Step-by-step derivation
                          1. Applied rewrites21.0%

                            \[\leadsto \frac{0 - t \cdot t}{\color{blue}{0 + t}} \]
                          2. Step-by-step derivation
                            1. Applied rewrites21.0%

                              \[\leadsto \frac{\left(-t\right) \cdot t}{\color{blue}{t}} \]
                            2. Applied rewrites2.5%

                              \[\leadsto \color{blue}{t} \]
                            3. Add Preprocessing

                            Developer Target 1: 99.6% accurate, 1.0× speedup?

                            \[\begin{array}{l} \\ \log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right) \end{array} \]
                            (FPCore (x y z t a)
                             :precision binary64
                             (+ (log (+ x y)) (+ (- (log z) t) (* (- a 0.5) (log t)))))
                            double code(double x, double y, double z, double t, double a) {
                            	return log((x + y)) + ((log(z) - t) + ((a - 0.5) * log(t)));
                            }
                            
                            real(8) function code(x, y, z, t, a)
                                real(8), intent (in) :: x
                                real(8), intent (in) :: y
                                real(8), intent (in) :: z
                                real(8), intent (in) :: t
                                real(8), intent (in) :: a
                                code = log((x + y)) + ((log(z) - t) + ((a - 0.5d0) * log(t)))
                            end function
                            
                            public static double code(double x, double y, double z, double t, double a) {
                            	return Math.log((x + y)) + ((Math.log(z) - t) + ((a - 0.5) * Math.log(t)));
                            }
                            
                            def code(x, y, z, t, a):
                            	return math.log((x + y)) + ((math.log(z) - t) + ((a - 0.5) * math.log(t)))
                            
                            function code(x, y, z, t, a)
                            	return Float64(log(Float64(x + y)) + Float64(Float64(log(z) - t) + Float64(Float64(a - 0.5) * log(t))))
                            end
                            
                            function tmp = code(x, y, z, t, a)
                            	tmp = log((x + y)) + ((log(z) - t) + ((a - 0.5) * log(t)));
                            end
                            
                            code[x_, y_, z_, t_, a_] := N[(N[Log[N[(x + y), $MachinePrecision]], $MachinePrecision] + N[(N[(N[Log[z], $MachinePrecision] - t), $MachinePrecision] + N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
                            
                            \begin{array}{l}
                            
                            \\
                            \log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right)
                            \end{array}
                            

                            Reproduce

                            ?
                            herbie shell --seed 2024277 
                            (FPCore (x y z t a)
                              :name "Numeric.SpecFunctions:logGammaL from math-functions-0.1.5.2"
                              :precision binary64
                            
                              :alt
                              (! :herbie-platform default (+ (log (+ x y)) (+ (- (log z) t) (* (- a 1/2) (log t)))))
                            
                              (+ (- (+ (log (+ x y)) (log z)) t) (* (- a 0.5) (log t))))