Numeric.SpecFunctions:logGammaL from math-functions-0.1.5.2

Percentage Accurate: 99.6% → 99.6%
Time: 36.7s
Alternatives: 11
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 11 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?

\[\begin{array}{l} \\ \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \end{array} \]
(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}
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. Add Preprocessing

Alternative 2: 94.3% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \log \left(x + y\right) + \log z\\ t_2 := \left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\\ \mathbf{if}\;t\_1 \leq -720:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq 720:\\ \;\;\;\;\left(\frac{\log \left(\frac{1}{x + y} \cdot \frac{1}{z}\right)}{-1} + \log t \cdot \left(a + -0.5\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (let* ((t_1 (+ (log (+ x y)) (log z)))
        (t_2 (+ (* (- a 0.5) (log t)) (- (log z) t))))
   (if (<= t_1 -720.0)
     t_2
     (if (<= t_1 720.0)
       (-
        (+ (/ (log (* (/ 1.0 (+ x y)) (/ 1.0 z))) -1.0) (* (log t) (+ a -0.5)))
        t)
       t_2))))
double code(double x, double y, double z, double t, double a) {
	double t_1 = log((x + y)) + log(z);
	double t_2 = ((a - 0.5) * log(t)) + (log(z) - t);
	double tmp;
	if (t_1 <= -720.0) {
		tmp = t_2;
	} else if (t_1 <= 720.0) {
		tmp = ((log(((1.0 / (x + y)) * (1.0 / z))) / -1.0) + (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((x + y)) + log(z)
    t_2 = ((a - 0.5d0) * log(t)) + (log(z) - t)
    if (t_1 <= (-720.0d0)) then
        tmp = t_2
    else if (t_1 <= 720.0d0) then
        tmp = ((log(((1.0d0 / (x + y)) * (1.0d0 / z))) / (-1.0d0)) + (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((x + y)) + Math.log(z);
	double t_2 = ((a - 0.5) * Math.log(t)) + (Math.log(z) - t);
	double tmp;
	if (t_1 <= -720.0) {
		tmp = t_2;
	} else if (t_1 <= 720.0) {
		tmp = ((Math.log(((1.0 / (x + y)) * (1.0 / z))) / -1.0) + (Math.log(t) * (a + -0.5))) - t;
	} else {
		tmp = t_2;
	}
	return tmp;
}
def code(x, y, z, t, a):
	t_1 = math.log((x + y)) + math.log(z)
	t_2 = ((a - 0.5) * math.log(t)) + (math.log(z) - t)
	tmp = 0
	if t_1 <= -720.0:
		tmp = t_2
	elif t_1 <= 720.0:
		tmp = ((math.log(((1.0 / (x + y)) * (1.0 / z))) / -1.0) + (math.log(t) * (a + -0.5))) - t
	else:
		tmp = t_2
	return tmp
function code(x, y, z, t, a)
	t_1 = Float64(log(Float64(x + y)) + log(z))
	t_2 = Float64(Float64(Float64(a - 0.5) * log(t)) + Float64(log(z) - t))
	tmp = 0.0
	if (t_1 <= -720.0)
		tmp = t_2;
	elseif (t_1 <= 720.0)
		tmp = Float64(Float64(Float64(log(Float64(Float64(1.0 / Float64(x + y)) * Float64(1.0 / z))) / -1.0) + 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((x + y)) + log(z);
	t_2 = ((a - 0.5) * log(t)) + (log(z) - t);
	tmp = 0.0;
	if (t_1 <= -720.0)
		tmp = t_2;
	elseif (t_1 <= 720.0)
		tmp = ((log(((1.0 / (x + y)) * (1.0 / z))) / -1.0) + (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[N[(x + y), $MachinePrecision]], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision] + N[(N[Log[z], $MachinePrecision] - t), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, -720.0], t$95$2, If[LessEqual[t$95$1, 720.0], N[(N[(N[(N[Log[N[(N[(1.0 / N[(x + y), $MachinePrecision]), $MachinePrecision] * N[(1.0 / z), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / -1.0), $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 \left(x + y\right) + \log z\\
t_2 := \left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\\
\mathbf{if}\;t\_1 \leq -720:\\
\;\;\;\;t\_2\\

\mathbf{elif}\;t\_1 \leq 720:\\
\;\;\;\;\left(\frac{\log \left(\frac{1}{x + y} \cdot \frac{1}{z}\right)}{-1} + \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)) < -720 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. Step-by-step derivation
      1. lift-+.f64N/A

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(\log z + \left(\color{blue}{\left(-t\right)} + \log \left(x + y\right)\right)\right) + \left(a - 0.5\right) \cdot \log t \]
    4. Applied rewrites99.8%

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

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

        \[\leadsto \left(\log z + \color{blue}{\left(\mathsf{neg}\left(t\right)\right)}\right) + \left(a - \frac{1}{2}\right) \cdot \log t \]
      2. lower-neg.f6484.2

        \[\leadsto \left(\log z + \color{blue}{\left(-t\right)}\right) + \left(a - 0.5\right) \cdot \log t \]
    7. Applied rewrites84.2%

      \[\leadsto \left(\log z + \color{blue}{\left(-t\right)}\right) + \left(a - 0.5\right) \cdot \log t \]

    if -720 < (+.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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(\log z + \left(\color{blue}{\left(-t\right)} + \log \left(x + y\right)\right)\right) + \left(a - 0.5\right) \cdot \log t \]
    4. Applied rewrites99.6%

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(\left(\log z + \log \left(x + y\right)\right) + \log t \cdot \color{blue}{\left(-0.5 + a\right)}\right) - t \]
    7. Applied rewrites99.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(\left(\log z + \log \left(x + y\right)\right) + \left(-\left(-\log t\right) \cdot \color{blue}{\left(a + -0.5\right)}\right)\right) - t \]
    10. Applied rewrites99.6%

      \[\leadsto \color{blue}{\left(\left(\log z + \log \left(x + y\right)\right) + \left(-\left(-\log t\right) \cdot \left(a + -0.5\right)\right)\right)} - t \]
    11. Step-by-step derivation
      1. lift-+.f64N/A

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(\color{blue}{\frac{\left(\mathsf{neg}\left(\log \left(x + y\right)\right)\right) \cdot 1 + -1 \cdot \log z}{-1}} + \left(\mathsf{neg}\left(\left(\mathsf{neg}\left(\log t\right)\right) \cdot \left(a + \frac{-1}{2}\right)\right)\right)\right) - t \]
    12. Applied rewrites99.6%

      \[\leadsto \left(\color{blue}{\frac{\log \left(\frac{1}{x + y} \cdot \frac{1}{z}\right)}{-1}} + \left(-\left(-\log t\right) \cdot \left(a + -0.5\right)\right)\right) - t \]
  3. Recombined 2 regimes into one program.
  4. Final simplification95.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\log \left(x + y\right) + \log z \leq -720:\\ \;\;\;\;\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\\ \mathbf{elif}\;\log \left(x + y\right) + \log z \leq 720:\\ \;\;\;\;\left(\frac{\log \left(\frac{1}{x + y} \cdot \frac{1}{z}\right)}{-1} + \log t \cdot \left(a + -0.5\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 94.2% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \log \left(x + y\right) + \log z\\ t_2 := \left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\\ \mathbf{if}\;t\_1 \leq -750:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq 690:\\ \;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, \log \left(\left(x + y\right) \cdot z\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (let* ((t_1 (+ (log (+ x y)) (log z)))
        (t_2 (+ (* (- a 0.5) (log t)) (- (log z) t))))
   (if (<= t_1 -750.0)
     t_2
     (if (<= t_1 690.0)
       (- (fma (+ a -0.5) (log t) (log (* (+ x y) z))) t)
       t_2))))
double code(double x, double y, double z, double t, double a) {
	double t_1 = log((x + y)) + log(z);
	double t_2 = ((a - 0.5) * log(t)) + (log(z) - t);
	double tmp;
	if (t_1 <= -750.0) {
		tmp = t_2;
	} else if (t_1 <= 690.0) {
		tmp = fma((a + -0.5), log(t), log(((x + y) * z))) - t;
	} else {
		tmp = t_2;
	}
	return tmp;
}
function code(x, y, z, t, a)
	t_1 = Float64(log(Float64(x + y)) + log(z))
	t_2 = Float64(Float64(Float64(a - 0.5) * log(t)) + Float64(log(z) - t))
	tmp = 0.0
	if (t_1 <= -750.0)
		tmp = t_2;
	elseif (t_1 <= 690.0)
		tmp = Float64(fma(Float64(a + -0.5), log(t), log(Float64(Float64(x + y) * z))) - t);
	else
		tmp = t_2;
	end
	return tmp
end
code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[Log[N[(x + y), $MachinePrecision]], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision] + N[(N[Log[z], $MachinePrecision] - t), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, -750.0], t$95$2, If[LessEqual[t$95$1, 690.0], N[(N[(N[(a + -0.5), $MachinePrecision] * N[Log[t], $MachinePrecision] + N[Log[N[(N[(x + y), $MachinePrecision] * z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision], t$95$2]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \log \left(x + y\right) + \log z\\
t_2 := \left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\\
\mathbf{if}\;t\_1 \leq -750:\\
\;\;\;\;t\_2\\

\mathbf{elif}\;t\_1 \leq 690:\\
\;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, \log \left(\left(x + y\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 690 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 z))

    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. Step-by-step derivation
      1. lift-+.f64N/A

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

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

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

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

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

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

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

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

        \[\leadsto \left(\log z + \color{blue}{\left(\left(\mathsf{neg}\left(t\right)\right) + \log \left(x + y\right)\right)}\right) + \left(a - \frac{1}{2}\right) \cdot \log t \]
      10. lower-neg.f6499.7

        \[\leadsto \left(\log z + \left(\color{blue}{\left(-t\right)} + \log \left(x + y\right)\right)\right) + \left(a - 0.5\right) \cdot \log t \]
    4. Applied rewrites99.7%

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

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

        \[\leadsto \left(\log z + \color{blue}{\left(\mathsf{neg}\left(t\right)\right)}\right) + \left(a - \frac{1}{2}\right) \cdot \log t \]
      2. lower-neg.f6483.2

        \[\leadsto \left(\log z + \color{blue}{\left(-t\right)}\right) + \left(a - 0.5\right) \cdot \log t \]
    7. Applied rewrites83.2%

      \[\leadsto \left(\log z + \color{blue}{\left(-t\right)}\right) + \left(a - 0.5\right) \cdot \log t \]

    if -750 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < 690

    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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \color{blue}{\left(\left(a - \frac{1}{2}\right) \cdot \log t + \left(\log \left(x + y\right) + \log z\right)\right) - t} \]
    4. Applied rewrites99.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(\left(x + y\right) \cdot z\right)\right) - t} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification95.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\log \left(x + y\right) + \log z \leq -750:\\ \;\;\;\;\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\\ \mathbf{elif}\;\log \left(x + y\right) + \log z \leq 690:\\ \;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, \log \left(\left(x + y\right) \cdot z\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 68.7% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \log \left(x + y\right) + \log z\\ t_2 := \left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\\ \mathbf{if}\;t\_1 \leq -750:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq 690:\\ \;\;\;\;\log \left(y \cdot z\right) + \left(\log t \cdot \left(a + -0.5\right) - t\right)\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (let* ((t_1 (+ (log (+ x y)) (log z)))
        (t_2 (+ (* (- a 0.5) (log t)) (- (log z) t))))
   (if (<= t_1 -750.0)
     t_2
     (if (<= t_1 690.0) (+ (log (* y z)) (- (* (log t) (+ a -0.5)) t)) t_2))))
double code(double x, double y, double z, double t, double a) {
	double t_1 = log((x + y)) + log(z);
	double t_2 = ((a - 0.5) * log(t)) + (log(z) - t);
	double tmp;
	if (t_1 <= -750.0) {
		tmp = t_2;
	} else if (t_1 <= 690.0) {
		tmp = log((y * z)) + ((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((x + y)) + log(z)
    t_2 = ((a - 0.5d0) * log(t)) + (log(z) - t)
    if (t_1 <= (-750.0d0)) then
        tmp = t_2
    else if (t_1 <= 690.0d0) then
        tmp = log((y * z)) + ((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((x + y)) + Math.log(z);
	double t_2 = ((a - 0.5) * Math.log(t)) + (Math.log(z) - t);
	double tmp;
	if (t_1 <= -750.0) {
		tmp = t_2;
	} else if (t_1 <= 690.0) {
		tmp = Math.log((y * z)) + ((Math.log(t) * (a + -0.5)) - t);
	} else {
		tmp = t_2;
	}
	return tmp;
}
def code(x, y, z, t, a):
	t_1 = math.log((x + y)) + math.log(z)
	t_2 = ((a - 0.5) * math.log(t)) + (math.log(z) - t)
	tmp = 0
	if t_1 <= -750.0:
		tmp = t_2
	elif t_1 <= 690.0:
		tmp = math.log((y * z)) + ((math.log(t) * (a + -0.5)) - t)
	else:
		tmp = t_2
	return tmp
function code(x, y, z, t, a)
	t_1 = Float64(log(Float64(x + y)) + log(z))
	t_2 = Float64(Float64(Float64(a - 0.5) * log(t)) + Float64(log(z) - t))
	tmp = 0.0
	if (t_1 <= -750.0)
		tmp = t_2;
	elseif (t_1 <= 690.0)
		tmp = Float64(log(Float64(y * z)) + Float64(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((x + y)) + log(z);
	t_2 = ((a - 0.5) * log(t)) + (log(z) - t);
	tmp = 0.0;
	if (t_1 <= -750.0)
		tmp = t_2;
	elseif (t_1 <= 690.0)
		tmp = log((y * z)) + ((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[N[(x + y), $MachinePrecision]], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision] + N[(N[Log[z], $MachinePrecision] - t), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, -750.0], t$95$2, If[LessEqual[t$95$1, 690.0], N[(N[Log[N[(y * z), $MachinePrecision]], $MachinePrecision] + N[(N[(N[Log[t], $MachinePrecision] * N[(a + -0.5), $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]), $MachinePrecision], t$95$2]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \log \left(x + y\right) + \log z\\
t_2 := \left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\\
\mathbf{if}\;t\_1 \leq -750:\\
\;\;\;\;t\_2\\

\mathbf{elif}\;t\_1 \leq 690:\\
\;\;\;\;\log \left(y \cdot z\right) + \left(\log t \cdot \left(a + -0.5\right) - t\right)\\

\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 690 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 z))

    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. Step-by-step derivation
      1. lift-+.f64N/A

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

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

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

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

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

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

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

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

        \[\leadsto \left(\log z + \color{blue}{\left(\left(\mathsf{neg}\left(t\right)\right) + \log \left(x + y\right)\right)}\right) + \left(a - \frac{1}{2}\right) \cdot \log t \]
      10. lower-neg.f6499.7

        \[\leadsto \left(\log z + \left(\color{blue}{\left(-t\right)} + \log \left(x + y\right)\right)\right) + \left(a - 0.5\right) \cdot \log t \]
    4. Applied rewrites99.7%

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

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

        \[\leadsto \left(\log z + \color{blue}{\left(\mathsf{neg}\left(t\right)\right)}\right) + \left(a - \frac{1}{2}\right) \cdot \log t \]
      2. lower-neg.f6483.2

        \[\leadsto \left(\log z + \color{blue}{\left(-t\right)}\right) + \left(a - 0.5\right) \cdot \log t \]
    7. Applied rewrites83.2%

      \[\leadsto \left(\log z + \color{blue}{\left(-t\right)}\right) + \left(a - 0.5\right) \cdot \log t \]

    if -750 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < 690

    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. Applied rewrites65.9%

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \log \left(z \cdot y\right) + \left(\log t \cdot \left(a + \color{blue}{\frac{-1}{2}}\right) - t\right) \]
      11. lower-+.f6471.3

        \[\leadsto \log \left(z \cdot y\right) + \left(\log t \cdot \color{blue}{\left(a + -0.5\right)} - t\right) \]
    6. Applied rewrites71.3%

      \[\leadsto \color{blue}{\log \left(z \cdot y\right) + \left(\log t \cdot \left(a + -0.5\right) - t\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification74.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\log \left(x + y\right) + \log z \leq -750:\\ \;\;\;\;\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\\ \mathbf{elif}\;\log \left(x + y\right) + \log z \leq 690:\\ \;\;\;\;\log \left(y \cdot z\right) + \left(\log t \cdot \left(a + -0.5\right) - t\right)\\ \mathbf{else}:\\ \;\;\;\;\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 99.6% accurate, 1.0× speedup?

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

\\
\mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right) + \left(\log z - 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. Step-by-step derivation
    1. lift-+.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \color{blue}{\left(\left(a - \frac{1}{2}\right) \cdot \log t + \log \left(x + y\right)\right) + \left(\log z - t\right)} \]
  4. Applied rewrites99.6%

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

Alternative 6: 68.6% accurate, 1.0× speedup?

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

\\
\log y + \mathsf{fma}\left(\log t, a + -0.5, \log z - 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. Taylor expanded in x around 0

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \log y + \mathsf{fma}\left(\log t, a + \frac{-1}{2}, \color{blue}{\log z - t}\right) \]
    12. lower-log.f6474.3

      \[\leadsto \log y + \mathsf{fma}\left(\log t, a + -0.5, \color{blue}{\log z} - t\right) \]
  5. Applied rewrites74.3%

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

Alternative 7: 77.8% accurate, 1.5× speedup?

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

\\
\left(a - 0.5\right) \cdot \log t + \left(\log z - 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. Step-by-step derivation
    1. lift-+.f64N/A

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

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

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

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

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

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

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

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

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

      \[\leadsto \left(\log z + \left(\color{blue}{\left(-t\right)} + \log \left(x + y\right)\right)\right) + \left(a - 0.5\right) \cdot \log t \]
  4. Applied rewrites99.6%

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

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

      \[\leadsto \left(\log z + \color{blue}{\left(\mathsf{neg}\left(t\right)\right)}\right) + \left(a - \frac{1}{2}\right) \cdot \log t \]
    2. lower-neg.f6478.8

      \[\leadsto \left(\log z + \color{blue}{\left(-t\right)}\right) + \left(a - 0.5\right) \cdot \log t \]
  7. Applied rewrites78.8%

    \[\leadsto \left(\log z + \color{blue}{\left(-t\right)}\right) + \left(a - 0.5\right) \cdot \log t \]
  8. Final simplification78.8%

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

Alternative 8: 61.5% accurate, 2.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq 9.8 \cdot 10^{+58}:\\ \;\;\;\;a \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;-t\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (if (<= t 9.8e+58) (* a (log t)) (- t)))
double code(double x, double y, double z, double t, double a) {
	double tmp;
	if (t <= 9.8e+58) {
		tmp = a * log(t);
	} 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 <= 9.8d+58) then
        tmp = a * log(t)
    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 <= 9.8e+58) {
		tmp = a * Math.log(t);
	} else {
		tmp = -t;
	}
	return tmp;
}
def code(x, y, z, t, a):
	tmp = 0
	if t <= 9.8e+58:
		tmp = a * math.log(t)
	else:
		tmp = -t
	return tmp
function code(x, y, z, t, a)
	tmp = 0.0
	if (t <= 9.8e+58)
		tmp = Float64(a * log(t));
	else
		tmp = Float64(-t);
	end
	return tmp
end
function tmp_2 = code(x, y, z, t, a)
	tmp = 0.0;
	if (t <= 9.8e+58)
		tmp = a * log(t);
	else
		tmp = -t;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_, a_] := If[LessEqual[t, 9.8e+58], N[(a * N[Log[t], $MachinePrecision]), $MachinePrecision], (-t)]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq 9.8 \cdot 10^{+58}:\\
\;\;\;\;a \cdot \log t\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < 9.80000000000000037e58

    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. *-commutativeN/A

        \[\leadsto \color{blue}{\log t \cdot a} \]
      2. lower-*.f64N/A

        \[\leadsto \color{blue}{\log t \cdot a} \]
      3. lower-log.f6454.0

        \[\leadsto \color{blue}{\log t} \cdot a \]
    5. Applied rewrites54.0%

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

    if 9.80000000000000037e58 < 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.f6481.5

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

      \[\leadsto \color{blue}{-t} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification65.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq 9.8 \cdot 10^{+58}:\\ \;\;\;\;a \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;-t\\ \end{array} \]
  5. Add Preprocessing

Alternative 9: 77.6% accurate, 2.9× speedup?

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

\\
\left(a - 0.5\right) \cdot \log t - 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

    \[\leadsto \color{blue}{-1 \cdot t} + \left(a - \frac{1}{2}\right) \cdot \log t \]
  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.f6478.4

      \[\leadsto \color{blue}{\left(-t\right)} + \left(a - 0.5\right) \cdot \log t \]
  5. Applied rewrites78.4%

    \[\leadsto \color{blue}{\left(-t\right)} + \left(a - 0.5\right) \cdot \log t \]
  6. Final simplification78.4%

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

Alternative 10: 74.9% accurate, 2.9× speedup?

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

\\
a \cdot \log t - 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. Step-by-step derivation
    1. lift-+.f64N/A

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

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

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

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

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

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

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

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

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

      \[\leadsto \left(\log z + \left(\color{blue}{\left(-t\right)} + \log \left(x + y\right)\right)\right) + \left(a - 0.5\right) \cdot \log t \]
  4. Applied rewrites99.6%

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \left(\left(\log z + \log \left(x + y\right)\right) + \color{blue}{\log t} \cdot \left(\frac{-1}{2} + a\right)\right) - t \]
    11. lower-+.f6499.7

      \[\leadsto \left(\left(\log z + \log \left(x + y\right)\right) + \log t \cdot \color{blue}{\left(-0.5 + a\right)}\right) - t \]
  7. Applied rewrites99.7%

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

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

      \[\leadsto \color{blue}{a \cdot \log t} - t \]
    2. lower-log.f6475.8

      \[\leadsto a \cdot \color{blue}{\log t} - t \]
  10. Applied rewrites75.8%

    \[\leadsto \color{blue}{a \cdot \log t} - t \]
  11. Add Preprocessing

Alternative 11: 37.3% 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.f6438.7

      \[\leadsto \color{blue}{-t} \]
  5. Applied rewrites38.7%

    \[\leadsto \color{blue}{-t} \]
  6. 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 2024220 
(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))))