Numeric.SpecFunctions:logGammaL from math-functions-0.1.5.2

Percentage Accurate: 99.6% → 99.6%
Time: 10.9s
Alternatives: 12
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 12 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: 97.4% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(a - 0.5\right) \cdot \log t\\ t_2 := \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + t\_1\\ \mathbf{if}\;t\_2 \leq -5000 \lor \neg \left(t\_2 \leq 2000\right):\\ \;\;\;\;{\left(\frac{-1}{t}\right)}^{-1} + t\_1\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(-0.5, \log t, \log \left(y + x\right)\right) + \log z\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (let* ((t_1 (* (- a 0.5) (log t)))
        (t_2 (+ (- (+ (log (+ x y)) (log z)) t) t_1)))
   (if (or (<= t_2 -5000.0) (not (<= t_2 2000.0)))
     (+ (pow (/ -1.0 t) -1.0) t_1)
     (+ (fma -0.5 (log t) (log (+ y x))) (log z)))))
double code(double x, double y, double z, double t, double a) {
	double t_1 = (a - 0.5) * log(t);
	double t_2 = ((log((x + y)) + log(z)) - t) + t_1;
	double tmp;
	if ((t_2 <= -5000.0) || !(t_2 <= 2000.0)) {
		tmp = pow((-1.0 / t), -1.0) + t_1;
	} else {
		tmp = fma(-0.5, log(t), log((y + x))) + log(z);
	}
	return tmp;
}
function code(x, y, z, t, a)
	t_1 = Float64(Float64(a - 0.5) * log(t))
	t_2 = Float64(Float64(Float64(log(Float64(x + y)) + log(z)) - t) + t_1)
	tmp = 0.0
	if ((t_2 <= -5000.0) || !(t_2 <= 2000.0))
		tmp = Float64((Float64(-1.0 / t) ^ -1.0) + t_1);
	else
		tmp = Float64(fma(-0.5, log(t), log(Float64(y + x))) + log(z));
	end
	return tmp
end
code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(N[Log[N[(x + y), $MachinePrecision]], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision] + t$95$1), $MachinePrecision]}, If[Or[LessEqual[t$95$2, -5000.0], N[Not[LessEqual[t$95$2, 2000.0]], $MachinePrecision]], N[(N[Power[N[(-1.0 / t), $MachinePrecision], -1.0], $MachinePrecision] + t$95$1), $MachinePrecision], N[(N[(-0.5 * N[Log[t], $MachinePrecision] + N[Log[N[(y + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \left(a - 0.5\right) \cdot \log t\\
t_2 := \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + t\_1\\
\mathbf{if}\;t\_2 \leq -5000 \lor \neg \left(t\_2 \leq 2000\right):\\
\;\;\;\;{\left(\frac{-1}{t}\right)}^{-1} + t\_1\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(-0.5, \log t, \log \left(y + x\right)\right) + \log z\\


\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))) < -5e3 or 2e3 < (+.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. 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

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

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

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

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

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

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

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{\left(\log \left(x + y\right) + \log z\right) - t}}} + \left(a - 0.5\right) \cdot \log t \]
    4. Applied rewrites72.5%

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

      \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - \frac{1}{2}\right) \cdot \log t \]
    6. Step-by-step derivation
      1. lower-/.f6497.1

        \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - 0.5\right) \cdot \log t \]
    7. Applied rewrites97.1%

      \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - 0.5\right) \cdot \log t \]

    if -5e3 < (+.f64 (-.f64 (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) t) (*.f64 (-.f64 a #s(literal 1/2 binary64)) (log.f64 t))) < 2e3

    1. Initial program 99.2%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Add Preprocessing
    3. Taylor expanded in a around 0

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\frac{-1}{2}, \log t, \log \left(y + x\right)\right) - \color{blue}{\left(t - \log z\right)} \]
      12. lower-log.f6498.7

        \[\leadsto \mathsf{fma}\left(-0.5, \log t, \log \left(y + x\right)\right) - \left(t - \color{blue}{\log z}\right) \]
    5. Applied rewrites98.7%

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

      \[\leadsto \log z + \color{blue}{\left(\log \left(x + y\right) + \frac{-1}{2} \cdot \log t\right)} \]
    7. Step-by-step derivation
      1. Applied rewrites97.2%

        \[\leadsto \mathsf{fma}\left(-0.5, \log t, \log \left(y + x\right)\right) + \color{blue}{\log z} \]
    8. Recombined 2 regimes into one program.
    9. Final simplification97.1%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \leq -5000 \lor \neg \left(\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \leq 2000\right):\\ \;\;\;\;{\left(\frac{-1}{t}\right)}^{-1} + \left(a - 0.5\right) \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(-0.5, \log t, \log \left(y + x\right)\right) + \log z\\ \end{array} \]
    10. Add Preprocessing

    Alternative 3: 92.8% accurate, 0.4× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(a - 0.5\right) \cdot \log t\\ t_2 := \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + t\_1\\ \mathbf{if}\;t\_2 \leq -20000000000000 \lor \neg \left(t\_2 \leq 1000\right):\\ \;\;\;\;{\left(\frac{-1}{t}\right)}^{-1} + t\_1\\ \mathbf{else}:\\ \;\;\;\;\log \left(z \cdot \left(y + x\right)\right) - \left(t - -0.5 \cdot \log t\right)\\ \end{array} \end{array} \]
    (FPCore (x y z t a)
     :precision binary64
     (let* ((t_1 (* (- a 0.5) (log t)))
            (t_2 (+ (- (+ (log (+ x y)) (log z)) t) t_1)))
       (if (or (<= t_2 -20000000000000.0) (not (<= t_2 1000.0)))
         (+ (pow (/ -1.0 t) -1.0) t_1)
         (- (log (* z (+ y x))) (- t (* -0.5 (log t)))))))
    double code(double x, double y, double z, double t, double a) {
    	double t_1 = (a - 0.5) * log(t);
    	double t_2 = ((log((x + y)) + log(z)) - t) + t_1;
    	double tmp;
    	if ((t_2 <= -20000000000000.0) || !(t_2 <= 1000.0)) {
    		tmp = pow((-1.0 / t), -1.0) + t_1;
    	} else {
    		tmp = log((z * (y + x))) - (t - (-0.5 * log(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) :: t_1
        real(8) :: t_2
        real(8) :: tmp
        t_1 = (a - 0.5d0) * log(t)
        t_2 = ((log((x + y)) + log(z)) - t) + t_1
        if ((t_2 <= (-20000000000000.0d0)) .or. (.not. (t_2 <= 1000.0d0))) then
            tmp = (((-1.0d0) / t) ** (-1.0d0)) + t_1
        else
            tmp = log((z * (y + x))) - (t - ((-0.5d0) * log(t)))
        end if
        code = tmp
    end function
    
    public static double code(double x, double y, double z, double t, double a) {
    	double t_1 = (a - 0.5) * Math.log(t);
    	double t_2 = ((Math.log((x + y)) + Math.log(z)) - t) + t_1;
    	double tmp;
    	if ((t_2 <= -20000000000000.0) || !(t_2 <= 1000.0)) {
    		tmp = Math.pow((-1.0 / t), -1.0) + t_1;
    	} else {
    		tmp = Math.log((z * (y + x))) - (t - (-0.5 * Math.log(t)));
    	}
    	return tmp;
    }
    
    def code(x, y, z, t, a):
    	t_1 = (a - 0.5) * math.log(t)
    	t_2 = ((math.log((x + y)) + math.log(z)) - t) + t_1
    	tmp = 0
    	if (t_2 <= -20000000000000.0) or not (t_2 <= 1000.0):
    		tmp = math.pow((-1.0 / t), -1.0) + t_1
    	else:
    		tmp = math.log((z * (y + x))) - (t - (-0.5 * math.log(t)))
    	return tmp
    
    function code(x, y, z, t, a)
    	t_1 = Float64(Float64(a - 0.5) * log(t))
    	t_2 = Float64(Float64(Float64(log(Float64(x + y)) + log(z)) - t) + t_1)
    	tmp = 0.0
    	if ((t_2 <= -20000000000000.0) || !(t_2 <= 1000.0))
    		tmp = Float64((Float64(-1.0 / t) ^ -1.0) + t_1);
    	else
    		tmp = Float64(log(Float64(z * Float64(y + x))) - Float64(t - Float64(-0.5 * log(t))));
    	end
    	return tmp
    end
    
    function tmp_2 = code(x, y, z, t, a)
    	t_1 = (a - 0.5) * log(t);
    	t_2 = ((log((x + y)) + log(z)) - t) + t_1;
    	tmp = 0.0;
    	if ((t_2 <= -20000000000000.0) || ~((t_2 <= 1000.0)))
    		tmp = ((-1.0 / t) ^ -1.0) + t_1;
    	else
    		tmp = log((z * (y + x))) - (t - (-0.5 * log(t)));
    	end
    	tmp_2 = tmp;
    end
    
    code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(N[Log[N[(x + y), $MachinePrecision]], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision] + t$95$1), $MachinePrecision]}, If[Or[LessEqual[t$95$2, -20000000000000.0], N[Not[LessEqual[t$95$2, 1000.0]], $MachinePrecision]], N[(N[Power[N[(-1.0 / t), $MachinePrecision], -1.0], $MachinePrecision] + t$95$1), $MachinePrecision], N[(N[Log[N[(z * N[(y + x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - N[(t - N[(-0.5 * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_1 := \left(a - 0.5\right) \cdot \log t\\
    t_2 := \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + t\_1\\
    \mathbf{if}\;t\_2 \leq -20000000000000 \lor \neg \left(t\_2 \leq 1000\right):\\
    \;\;\;\;{\left(\frac{-1}{t}\right)}^{-1} + t\_1\\
    
    \mathbf{else}:\\
    \;\;\;\;\log \left(z \cdot \left(y + x\right)\right) - \left(t - -0.5 \cdot \log t\right)\\
    
    
    \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 1e3 < (+.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. 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

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

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

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

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

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

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

          \[\leadsto \frac{1}{\color{blue}{\frac{1}{\left(\log \left(x + y\right) + \log z\right) - t}}} + \left(a - 0.5\right) \cdot \log t \]
      4. Applied rewrites68.5%

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

        \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - \frac{1}{2}\right) \cdot \log t \]
      6. Step-by-step derivation
        1. lower-/.f6494.1

          \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - 0.5\right) \cdot \log t \]
      7. Applied rewrites94.1%

        \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - 0.5\right) \cdot \log t \]

      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))) < 1e3

      1. Initial program 99.1%

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

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

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

          \[\leadsto \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \log t \cdot \color{blue}{\left(a - \frac{1}{2}\right)} \]
        4. flip3--N/A

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

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

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

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

          \[\leadsto \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \frac{\log t}{\color{blue}{\frac{1}{\frac{{a}^{3} - {\frac{1}{2}}^{3}}{a \cdot a + \left(\frac{1}{2} \cdot \frac{1}{2} + a \cdot \frac{1}{2}\right)}}}} \]
        9. flip3--N/A

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

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

          \[\leadsto \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \frac{\log t}{\color{blue}{\frac{1}{a - 0.5}}} \]
      4. Applied rewrites99.1%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \color{blue}{\log \left(z \cdot \left(y + x\right)\right)} - \left(t - \left(a - \frac{1}{2}\right) \cdot \log t\right) \]
        21. lower--.f6487.9

          \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \color{blue}{\left(t - \left(a - 0.5\right) \cdot \log t\right)} \]
      6. Applied rewrites87.9%

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

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

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

          \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\frac{-1}{2} \cdot \log t}\right) \]
        3. lower-log.f6484.6

          \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - -0.5 \cdot \color{blue}{\log t}\right) \]
      9. Applied rewrites84.6%

        \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \color{blue}{\left(t - -0.5 \cdot \log t\right)} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification91.9%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \leq -20000000000000 \lor \neg \left(\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \leq 1000\right):\\ \;\;\;\;{\left(\frac{-1}{t}\right)}^{-1} + \left(a - 0.5\right) \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;\log \left(z \cdot \left(y + x\right)\right) - \left(t - -0.5 \cdot \log t\right)\\ \end{array} \]
    5. Add Preprocessing

    Alternative 4: 92.8% accurate, 0.4× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(a - 0.5\right) \cdot \log t\\ t_2 := \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + t\_1\\ \mathbf{if}\;t\_2 \leq -20000000000000 \lor \neg \left(t\_2 \leq 1000\right):\\ \;\;\;\;{\left(\frac{-1}{t}\right)}^{-1} + t\_1\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(-0.5, \log t, \log \left(\left(y + x\right) \cdot z\right)\right) - t\\ \end{array} \end{array} \]
    (FPCore (x y z t a)
     :precision binary64
     (let* ((t_1 (* (- a 0.5) (log t)))
            (t_2 (+ (- (+ (log (+ x y)) (log z)) t) t_1)))
       (if (or (<= t_2 -20000000000000.0) (not (<= t_2 1000.0)))
         (+ (pow (/ -1.0 t) -1.0) t_1)
         (- (fma -0.5 (log t) (log (* (+ y x) z))) t))))
    double code(double x, double y, double z, double t, double a) {
    	double t_1 = (a - 0.5) * log(t);
    	double t_2 = ((log((x + y)) + log(z)) - t) + t_1;
    	double tmp;
    	if ((t_2 <= -20000000000000.0) || !(t_2 <= 1000.0)) {
    		tmp = pow((-1.0 / t), -1.0) + t_1;
    	} else {
    		tmp = fma(-0.5, log(t), log(((y + x) * z))) - t;
    	}
    	return tmp;
    }
    
    function code(x, y, z, t, a)
    	t_1 = Float64(Float64(a - 0.5) * log(t))
    	t_2 = Float64(Float64(Float64(log(Float64(x + y)) + log(z)) - t) + t_1)
    	tmp = 0.0
    	if ((t_2 <= -20000000000000.0) || !(t_2 <= 1000.0))
    		tmp = Float64((Float64(-1.0 / t) ^ -1.0) + t_1);
    	else
    		tmp = Float64(fma(-0.5, log(t), log(Float64(Float64(y + x) * z))) - t);
    	end
    	return tmp
    end
    
    code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(N[Log[N[(x + y), $MachinePrecision]], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision] + t$95$1), $MachinePrecision]}, If[Or[LessEqual[t$95$2, -20000000000000.0], N[Not[LessEqual[t$95$2, 1000.0]], $MachinePrecision]], N[(N[Power[N[(-1.0 / t), $MachinePrecision], -1.0], $MachinePrecision] + t$95$1), $MachinePrecision], N[(N[(-0.5 * N[Log[t], $MachinePrecision] + N[Log[N[(N[(y + x), $MachinePrecision] * z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_1 := \left(a - 0.5\right) \cdot \log t\\
    t_2 := \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + t\_1\\
    \mathbf{if}\;t\_2 \leq -20000000000000 \lor \neg \left(t\_2 \leq 1000\right):\\
    \;\;\;\;{\left(\frac{-1}{t}\right)}^{-1} + t\_1\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{fma}\left(-0.5, \log t, \log \left(\left(y + x\right) \cdot z\right)\right) - t\\
    
    
    \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 1e3 < (+.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. 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

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

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

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

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

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

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

          \[\leadsto \frac{1}{\color{blue}{\frac{1}{\left(\log \left(x + y\right) + \log z\right) - t}}} + \left(a - 0.5\right) \cdot \log t \]
      4. Applied rewrites68.5%

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

        \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - \frac{1}{2}\right) \cdot \log t \]
      6. Step-by-step derivation
        1. lower-/.f6494.1

          \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - 0.5\right) \cdot \log t \]
      7. Applied rewrites94.1%

        \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - 0.5\right) \cdot \log t \]

      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))) < 1e3

      1. Initial program 99.1%

        \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
      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

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

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

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

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

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

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

          \[\leadsto \frac{1}{\color{blue}{\frac{1}{\left(\log \left(x + y\right) + \log z\right) - t}}} + \left(a - 0.5\right) \cdot \log t \]
      4. Applied rewrites87.9%

        \[\leadsto \color{blue}{\frac{1}{\frac{1}{\log \left(z \cdot \left(y + x\right)\right) - t}}} + \left(a - 0.5\right) \cdot \log t \]
      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. lower-fma.f64N/A

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

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

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

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

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

          \[\leadsto \mathsf{fma}\left(\frac{-1}{2}, \log t, \log \left(\color{blue}{\left(y + x\right)} \cdot z\right)\right) - t \]
        9. lower-+.f6484.6

          \[\leadsto \mathsf{fma}\left(-0.5, \log t, \log \left(\color{blue}{\left(y + x\right)} \cdot z\right)\right) - t \]
      7. Applied rewrites84.6%

        \[\leadsto \color{blue}{\mathsf{fma}\left(-0.5, \log t, \log \left(\left(y + x\right) \cdot z\right)\right) - t} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification91.9%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \leq -20000000000000 \lor \neg \left(\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \leq 1000\right):\\ \;\;\;\;{\left(\frac{-1}{t}\right)}^{-1} + \left(a - 0.5\right) \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(-0.5, \log t, \log \left(\left(y + x\right) \cdot z\right)\right) - t\\ \end{array} \]
    5. Add Preprocessing

    Alternative 5: 93.6% accurate, 0.5× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_1 := \log \left(x + y\right) + \log z\\ \mathbf{if}\;t\_1 \leq -800 \lor \neg \left(t\_1 \leq 705\right):\\ \;\;\;\;{\left(\frac{-1}{t}\right)}^{-1} + \left(a - 0.5\right) \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a - 0.5, \log t, \log \left(z \cdot \left(y + x\right)\right) - t\right)\\ \end{array} \end{array} \]
    (FPCore (x y z t a)
     :precision binary64
     (let* ((t_1 (+ (log (+ x y)) (log z))))
       (if (or (<= t_1 -800.0) (not (<= t_1 705.0)))
         (+ (pow (/ -1.0 t) -1.0) (* (- a 0.5) (log t)))
         (fma (- a 0.5) (log t) (- (log (* z (+ y x))) t)))))
    double code(double x, double y, double z, double t, double a) {
    	double t_1 = log((x + y)) + log(z);
    	double tmp;
    	if ((t_1 <= -800.0) || !(t_1 <= 705.0)) {
    		tmp = pow((-1.0 / t), -1.0) + ((a - 0.5) * log(t));
    	} else {
    		tmp = fma((a - 0.5), log(t), (log((z * (y + x))) - t));
    	}
    	return tmp;
    }
    
    function code(x, y, z, t, a)
    	t_1 = Float64(log(Float64(x + y)) + log(z))
    	tmp = 0.0
    	if ((t_1 <= -800.0) || !(t_1 <= 705.0))
    		tmp = Float64((Float64(-1.0 / t) ^ -1.0) + Float64(Float64(a - 0.5) * log(t)));
    	else
    		tmp = fma(Float64(a - 0.5), log(t), Float64(log(Float64(z * Float64(y + x))) - t));
    	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]}, If[Or[LessEqual[t$95$1, -800.0], N[Not[LessEqual[t$95$1, 705.0]], $MachinePrecision]], N[(N[Power[N[(-1.0 / t), $MachinePrecision], -1.0], $MachinePrecision] + N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision] + N[(N[Log[N[(z * N[(y + x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - t), $MachinePrecision]), $MachinePrecision]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_1 := \log \left(x + y\right) + \log z\\
    \mathbf{if}\;t\_1 \leq -800 \lor \neg \left(t\_1 \leq 705\right):\\
    \;\;\;\;{\left(\frac{-1}{t}\right)}^{-1} + \left(a - 0.5\right) \cdot \log t\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{fma}\left(a - 0.5, \log t, \log \left(z \cdot \left(y + x\right)\right) - t\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < -800 or 705 < (+.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

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

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

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

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

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

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

          \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left(\log \left(x + y\right) + \log z\right) - t}}} + \left(a - \frac{1}{2}\right) \cdot \log t \]
        8. lower-/.f6499.5

          \[\leadsto \frac{1}{\color{blue}{\frac{1}{\left(\log \left(x + y\right) + \log z\right) - t}}} + \left(a - 0.5\right) \cdot \log t \]
      4. Applied rewrites4.9%

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

        \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - \frac{1}{2}\right) \cdot \log t \]
      6. Step-by-step derivation
        1. lower-/.f6478.7

          \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - 0.5\right) \cdot \log t \]
      7. Applied rewrites78.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - 0.5\right) \cdot \log t \]

      if -800 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < 705

      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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(z \cdot \left(y + x\right)\right) - t\right)} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification93.8%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\log \left(x + y\right) + \log z \leq -800 \lor \neg \left(\log \left(x + y\right) + \log z \leq 705\right):\\ \;\;\;\;{\left(\frac{-1}{t}\right)}^{-1} + \left(a - 0.5\right) \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a - 0.5, \log t, \log \left(z \cdot \left(y + x\right)\right) - t\right)\\ \end{array} \]
    5. Add Preprocessing

    Alternative 6: 98.4% accurate, 1.0× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a - 0.5 \leq -100 \lor \neg \left(a - 0.5 \leq -0.48\right):\\ \;\;\;\;{\left(\frac{-1}{t}\right)}^{-1} + \left(a - 0.5\right) \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(-0.5, \log t, \log \left(y + x\right)\right) - \left(t - \log z\right)\\ \end{array} \end{array} \]
    (FPCore (x y z t a)
     :precision binary64
     (if (or (<= (- a 0.5) -100.0) (not (<= (- a 0.5) -0.48)))
       (+ (pow (/ -1.0 t) -1.0) (* (- a 0.5) (log t)))
       (- (fma -0.5 (log t) (log (+ y x))) (- t (log z)))))
    double code(double x, double y, double z, double t, double a) {
    	double tmp;
    	if (((a - 0.5) <= -100.0) || !((a - 0.5) <= -0.48)) {
    		tmp = pow((-1.0 / t), -1.0) + ((a - 0.5) * log(t));
    	} else {
    		tmp = fma(-0.5, log(t), log((y + x))) - (t - log(z));
    	}
    	return tmp;
    }
    
    function code(x, y, z, t, a)
    	tmp = 0.0
    	if ((Float64(a - 0.5) <= -100.0) || !(Float64(a - 0.5) <= -0.48))
    		tmp = Float64((Float64(-1.0 / t) ^ -1.0) + Float64(Float64(a - 0.5) * log(t)));
    	else
    		tmp = Float64(fma(-0.5, log(t), log(Float64(y + x))) - Float64(t - log(z)));
    	end
    	return tmp
    end
    
    code[x_, y_, z_, t_, a_] := If[Or[LessEqual[N[(a - 0.5), $MachinePrecision], -100.0], N[Not[LessEqual[N[(a - 0.5), $MachinePrecision], -0.48]], $MachinePrecision]], N[(N[Power[N[(-1.0 / t), $MachinePrecision], -1.0], $MachinePrecision] + N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(-0.5 * N[Log[t], $MachinePrecision] + N[Log[N[(y + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - N[(t - N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;a - 0.5 \leq -100 \lor \neg \left(a - 0.5 \leq -0.48\right):\\
    \;\;\;\;{\left(\frac{-1}{t}\right)}^{-1} + \left(a - 0.5\right) \cdot \log t\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{fma}\left(-0.5, \log t, \log \left(y + x\right)\right) - \left(t - \log z\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (-.f64 a #s(literal 1/2 binary64)) < -100 or -0.47999999999999998 < (-.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. 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

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

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

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

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

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

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

          \[\leadsto \frac{1}{\color{blue}{\frac{1}{\left(\log \left(x + y\right) + \log z\right) - t}}} + \left(a - 0.5\right) \cdot \log t \]
      4. Applied rewrites73.3%

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

        \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - \frac{1}{2}\right) \cdot \log t \]
      6. Step-by-step derivation
        1. lower-/.f6497.5

          \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - 0.5\right) \cdot \log t \]
      7. Applied rewrites97.5%

        \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - 0.5\right) \cdot \log t \]

      if -100 < (-.f64 a #s(literal 1/2 binary64)) < -0.47999999999999998

      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 a around 0

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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \mathsf{fma}\left(\frac{-1}{2}, \log t, \log \left(y + x\right)\right) - \color{blue}{\left(t - \log z\right)} \]
        12. lower-log.f6499.3

          \[\leadsto \mathsf{fma}\left(-0.5, \log t, \log \left(y + x\right)\right) - \left(t - \color{blue}{\log z}\right) \]
      5. Applied rewrites99.3%

        \[\leadsto \color{blue}{\mathsf{fma}\left(-0.5, \log t, \log \left(y + x\right)\right) - \left(t - \log z\right)} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification98.3%

      \[\leadsto \begin{array}{l} \mathbf{if}\;a - 0.5 \leq -100 \lor \neg \left(a - 0.5 \leq -0.48\right):\\ \;\;\;\;{\left(\frac{-1}{t}\right)}^{-1} + \left(a - 0.5\right) \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(-0.5, \log t, \log \left(y + x\right)\right) - \left(t - \log z\right)\\ \end{array} \]
    5. Add Preprocessing

    Alternative 7: 81.3% accurate, 1.0× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a - 0.5 \leq -100 \lor \neg \left(a - 0.5 \leq -0.48\right):\\ \;\;\;\;{\left(\frac{-1}{t}\right)}^{-1} + \left(a - 0.5\right) \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(-0.5, \log t, \log y\right) - \left(t - \log z\right)\\ \end{array} \end{array} \]
    (FPCore (x y z t a)
     :precision binary64
     (if (or (<= (- a 0.5) -100.0) (not (<= (- a 0.5) -0.48)))
       (+ (pow (/ -1.0 t) -1.0) (* (- a 0.5) (log t)))
       (- (fma -0.5 (log t) (log y)) (- t (log z)))))
    double code(double x, double y, double z, double t, double a) {
    	double tmp;
    	if (((a - 0.5) <= -100.0) || !((a - 0.5) <= -0.48)) {
    		tmp = pow((-1.0 / t), -1.0) + ((a - 0.5) * log(t));
    	} else {
    		tmp = fma(-0.5, log(t), log(y)) - (t - log(z));
    	}
    	return tmp;
    }
    
    function code(x, y, z, t, a)
    	tmp = 0.0
    	if ((Float64(a - 0.5) <= -100.0) || !(Float64(a - 0.5) <= -0.48))
    		tmp = Float64((Float64(-1.0 / t) ^ -1.0) + Float64(Float64(a - 0.5) * log(t)));
    	else
    		tmp = Float64(fma(-0.5, log(t), log(y)) - Float64(t - log(z)));
    	end
    	return tmp
    end
    
    code[x_, y_, z_, t_, a_] := If[Or[LessEqual[N[(a - 0.5), $MachinePrecision], -100.0], N[Not[LessEqual[N[(a - 0.5), $MachinePrecision], -0.48]], $MachinePrecision]], N[(N[Power[N[(-1.0 / t), $MachinePrecision], -1.0], $MachinePrecision] + N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(-0.5 * N[Log[t], $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - N[(t - N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;a - 0.5 \leq -100 \lor \neg \left(a - 0.5 \leq -0.48\right):\\
    \;\;\;\;{\left(\frac{-1}{t}\right)}^{-1} + \left(a - 0.5\right) \cdot \log t\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{fma}\left(-0.5, \log t, \log y\right) - \left(t - \log z\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (-.f64 a #s(literal 1/2 binary64)) < -100 or -0.47999999999999998 < (-.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. 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

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

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

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

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

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

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

          \[\leadsto \frac{1}{\color{blue}{\frac{1}{\left(\log \left(x + y\right) + \log z\right) - t}}} + \left(a - 0.5\right) \cdot \log t \]
      4. Applied rewrites73.3%

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

        \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - \frac{1}{2}\right) \cdot \log t \]
      6. Step-by-step derivation
        1. lower-/.f6497.5

          \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - 0.5\right) \cdot \log t \]
      7. Applied rewrites97.5%

        \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - 0.5\right) \cdot \log t \]

      if -100 < (-.f64 a #s(literal 1/2 binary64)) < -0.47999999999999998

      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 a around 0

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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \mathsf{fma}\left(\frac{-1}{2}, \log t, \log \left(y + x\right)\right) - \color{blue}{\left(t - \log z\right)} \]
        12. lower-log.f6499.3

          \[\leadsto \mathsf{fma}\left(-0.5, \log t, \log \left(y + x\right)\right) - \left(t - \color{blue}{\log z}\right) \]
      5. Applied rewrites99.3%

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

        \[\leadsto \left(\log y + \frac{-1}{2} \cdot \log t\right) - \left(\color{blue}{t} - \log z\right) \]
      7. Step-by-step derivation
        1. Applied rewrites58.2%

          \[\leadsto \mathsf{fma}\left(-0.5, \log t, \log y\right) - \left(\color{blue}{t} - \log z\right) \]
      8. Recombined 2 regimes into one program.
      9. Final simplification79.2%

        \[\leadsto \begin{array}{l} \mathbf{if}\;a - 0.5 \leq -100 \lor \neg \left(a - 0.5 \leq -0.48\right):\\ \;\;\;\;{\left(\frac{-1}{t}\right)}^{-1} + \left(a - 0.5\right) \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(-0.5, \log t, \log y\right) - \left(t - \log z\right)\\ \end{array} \]
      10. Add Preprocessing

      Alternative 8: 69.4% accurate, 1.0× speedup?

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \log t, \log z\right) - \color{blue}{\left(t - \log y\right)} \]
        12. lower-log.f6467.0

          \[\leadsto \mathsf{fma}\left(a - 0.5, \log t, \log z\right) - \left(t - \color{blue}{\log y}\right) \]
      5. Applied rewrites67.0%

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

      Alternative 9: 77.4% accurate, 1.4× speedup?

      \[\begin{array}{l} \\ {\left(\frac{-1}{t}\right)}^{-1} + \left(a - 0.5\right) \cdot \log t \end{array} \]
      (FPCore (x y z t a)
       :precision binary64
       (+ (pow (/ -1.0 t) -1.0) (* (- a 0.5) (log t))))
      double code(double x, double y, double z, double t, double a) {
      	return pow((-1.0 / t), -1.0) + ((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 = (((-1.0d0) / t) ** (-1.0d0)) + ((a - 0.5d0) * log(t))
      end function
      
      public static double code(double x, double y, double z, double t, double a) {
      	return Math.pow((-1.0 / t), -1.0) + ((a - 0.5) * Math.log(t));
      }
      
      def code(x, y, z, t, a):
      	return math.pow((-1.0 / t), -1.0) + ((a - 0.5) * math.log(t))
      
      function code(x, y, z, t, a)
      	return Float64((Float64(-1.0 / t) ^ -1.0) + Float64(Float64(a - 0.5) * log(t)))
      end
      
      function tmp = code(x, y, z, t, a)
      	tmp = ((-1.0 / t) ^ -1.0) + ((a - 0.5) * log(t));
      end
      
      code[x_, y_, z_, t_, a_] := N[(N[Power[N[(-1.0 / t), $MachinePrecision], -1.0], $MachinePrecision] + N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      {\left(\frac{-1}{t}\right)}^{-1} + \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. 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

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

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

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

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

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

          \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left(\log \left(x + y\right) + \log z\right) - t}}} + \left(a - \frac{1}{2}\right) \cdot \log t \]
        8. lower-/.f6499.5

          \[\leadsto \frac{1}{\color{blue}{\frac{1}{\left(\log \left(x + y\right) + \log z\right) - t}}} + \left(a - 0.5\right) \cdot \log t \]
      4. Applied rewrites72.9%

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

        \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - \frac{1}{2}\right) \cdot \log t \]
      6. Step-by-step derivation
        1. lower-/.f6476.0

          \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - 0.5\right) \cdot \log t \]
      7. Applied rewrites76.0%

        \[\leadsto \frac{1}{\color{blue}{\frac{-1}{t}}} + \left(a - 0.5\right) \cdot \log t \]
      8. Final simplification76.0%

        \[\leadsto {\left(\frac{-1}{t}\right)}^{-1} + \left(a - 0.5\right) \cdot \log t \]
      9. Add Preprocessing

      Alternative 10: 74.9% accurate, 2.5× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq 1.85 \cdot 10^{-12}:\\ \;\;\;\;\log t \cdot a\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a \cdot \frac{\log t}{t}, t, -t\right)\\ \end{array} \end{array} \]
      (FPCore (x y z t a)
       :precision binary64
       (if (<= t 1.85e-12) (* (log t) a) (fma (* a (/ (log t) t)) t (- t))))
      double code(double x, double y, double z, double t, double a) {
      	double tmp;
      	if (t <= 1.85e-12) {
      		tmp = log(t) * a;
      	} else {
      		tmp = fma((a * (log(t) / t)), t, -t);
      	}
      	return tmp;
      }
      
      function code(x, y, z, t, a)
      	tmp = 0.0
      	if (t <= 1.85e-12)
      		tmp = Float64(log(t) * a);
      	else
      		tmp = fma(Float64(a * Float64(log(t) / t)), t, Float64(-t));
      	end
      	return tmp
      end
      
      code[x_, y_, z_, t_, a_] := If[LessEqual[t, 1.85e-12], N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision], N[(N[(a * N[(N[Log[t], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision] * t + (-t)), $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;t \leq 1.85 \cdot 10^{-12}:\\
      \;\;\;\;\log t \cdot a\\
      
      \mathbf{else}:\\
      \;\;\;\;\mathsf{fma}\left(a \cdot \frac{\log t}{t}, t, -t\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if t < 1.84999999999999999e-12

        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.f6446.8

            \[\leadsto \color{blue}{\log t} \cdot a \]
        5. Applied rewrites46.8%

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

        if 1.84999999999999999e-12 < 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. Step-by-step derivation
          1. lift-*.f64N/A

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

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

            \[\leadsto \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \log t \cdot \color{blue}{\left(a - \frac{1}{2}\right)} \]
          4. flip3--N/A

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

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

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

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

            \[\leadsto \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \frac{\log t}{\color{blue}{\frac{1}{\frac{{a}^{3} - {\frac{1}{2}}^{3}}{a \cdot a + \left(\frac{1}{2} \cdot \frac{1}{2} + a \cdot \frac{1}{2}\right)}}}} \]
          9. flip3--N/A

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

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

            \[\leadsto \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \frac{\log t}{\color{blue}{\frac{1}{a - 0.5}}} \]
        4. Applied rewrites99.8%

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

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

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

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

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

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

            \[\leadsto \color{blue}{\mathsf{fma}\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right), t, \mathsf{neg}\left(t\right)\right)} \]
        7. Applied rewrites99.8%

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

          \[\leadsto \mathsf{fma}\left(\frac{a \cdot \log t}{t}, t, -t\right) \]
        9. Step-by-step derivation
          1. Applied rewrites96.5%

            \[\leadsto \mathsf{fma}\left(a \cdot \frac{\log t}{t}, t, -t\right) \]
        10. Recombined 2 regimes into one program.
        11. Final simplification73.6%

          \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq 1.85 \cdot 10^{-12}:\\ \;\;\;\;\log t \cdot a\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a \cdot \frac{\log t}{t}, t, -t\right)\\ \end{array} \]
        12. Add Preprocessing

        Alternative 11: 62.3% accurate, 2.7× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -8200000 \lor \neg \left(a \leq 2.25 \cdot 10^{+62}\right):\\ \;\;\;\;\log t \cdot a\\ \mathbf{else}:\\ \;\;\;\;-t\\ \end{array} \end{array} \]
        (FPCore (x y z t a)
         :precision binary64
         (if (or (<= a -8200000.0) (not (<= a 2.25e+62))) (* (log t) a) (- t)))
        double code(double x, double y, double z, double t, double a) {
        	double tmp;
        	if ((a <= -8200000.0) || !(a <= 2.25e+62)) {
        		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 ((a <= (-8200000.0d0)) .or. (.not. (a <= 2.25d+62))) 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 ((a <= -8200000.0) || !(a <= 2.25e+62)) {
        		tmp = Math.log(t) * a;
        	} else {
        		tmp = -t;
        	}
        	return tmp;
        }
        
        def code(x, y, z, t, a):
        	tmp = 0
        	if (a <= -8200000.0) or not (a <= 2.25e+62):
        		tmp = math.log(t) * a
        	else:
        		tmp = -t
        	return tmp
        
        function code(x, y, z, t, a)
        	tmp = 0.0
        	if ((a <= -8200000.0) || !(a <= 2.25e+62))
        		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 ((a <= -8200000.0) || ~((a <= 2.25e+62)))
        		tmp = log(t) * a;
        	else
        		tmp = -t;
        	end
        	tmp_2 = tmp;
        end
        
        code[x_, y_, z_, t_, a_] := If[Or[LessEqual[a, -8200000.0], N[Not[LessEqual[a, 2.25e+62]], $MachinePrecision]], N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision], (-t)]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;a \leq -8200000 \lor \neg \left(a \leq 2.25 \cdot 10^{+62}\right):\\
        \;\;\;\;\log t \cdot a\\
        
        \mathbf{else}:\\
        \;\;\;\;-t\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if a < -8.2e6 or 2.24999999999999999e62 < a

          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 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.f6474.1

              \[\leadsto \color{blue}{\log t} \cdot a \]
          5. Applied rewrites74.1%

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

          if -8.2e6 < a < 2.24999999999999999e62

          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.f6447.6

              \[\leadsto \color{blue}{-t} \]
          5. Applied rewrites47.6%

            \[\leadsto \color{blue}{-t} \]
        3. Recombined 2 regimes into one program.
        4. Final simplification60.5%

          \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -8200000 \lor \neg \left(a \leq 2.25 \cdot 10^{+62}\right):\\ \;\;\;\;\log t \cdot a\\ \mathbf{else}:\\ \;\;\;\;-t\\ \end{array} \]
        5. Add Preprocessing

        Alternative 12: 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.f6436.9

            \[\leadsto \color{blue}{-t} \]
        5. Applied rewrites36.9%

          \[\leadsto \color{blue}{-t} \]
        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 2024324 
        (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))))