Numeric.SpecFunctions:logGammaL from math-functions-0.1.5.2

Percentage Accurate: 99.6% → 99.6%
Time: 12.3s
Alternatives: 17
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 17 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?

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

\\
\left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t
\end{array}
Derivation
  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. Final simplification99.7%

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

Alternative 2: 67.4% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t\\ t_2 := \left(\log t \cdot a + \log y\right) - t\\ \mathbf{if}\;t\_1 \leq -1000000:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq 2000:\\ \;\;\;\;-0.5 \cdot \log t + \left(\log y + \log z\right)\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (let* ((t_1 (- (- (+ (log z) (log (+ y x))) t) (* (- 0.5 a) (log t))))
        (t_2 (- (+ (* (log t) a) (log y)) t)))
   (if (<= t_1 -1000000.0)
     t_2
     (if (<= t_1 2000.0) (+ (* -0.5 (log t)) (+ (log y) (log z))) t_2))))
double code(double x, double y, double z, double t, double a) {
	double t_1 = ((log(z) + log((y + x))) - t) - ((0.5 - a) * log(t));
	double t_2 = ((log(t) * a) + log(y)) - t;
	double tmp;
	if (t_1 <= -1000000.0) {
		tmp = t_2;
	} else if (t_1 <= 2000.0) {
		tmp = (-0.5 * log(t)) + (log(y) + log(z));
	} else {
		tmp = t_2;
	}
	return tmp;
}
real(8) function code(x, y, z, t, a)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8), intent (in) :: a
    real(8) :: t_1
    real(8) :: t_2
    real(8) :: tmp
    t_1 = ((log(z) + log((y + x))) - t) - ((0.5d0 - a) * log(t))
    t_2 = ((log(t) * a) + log(y)) - t
    if (t_1 <= (-1000000.0d0)) then
        tmp = t_2
    else if (t_1 <= 2000.0d0) then
        tmp = ((-0.5d0) * log(t)) + (log(y) + log(z))
    else
        tmp = t_2
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t, double a) {
	double t_1 = ((Math.log(z) + Math.log((y + x))) - t) - ((0.5 - a) * Math.log(t));
	double t_2 = ((Math.log(t) * a) + Math.log(y)) - t;
	double tmp;
	if (t_1 <= -1000000.0) {
		tmp = t_2;
	} else if (t_1 <= 2000.0) {
		tmp = (-0.5 * Math.log(t)) + (Math.log(y) + Math.log(z));
	} else {
		tmp = t_2;
	}
	return tmp;
}
def code(x, y, z, t, a):
	t_1 = ((math.log(z) + math.log((y + x))) - t) - ((0.5 - a) * math.log(t))
	t_2 = ((math.log(t) * a) + math.log(y)) - t
	tmp = 0
	if t_1 <= -1000000.0:
		tmp = t_2
	elif t_1 <= 2000.0:
		tmp = (-0.5 * math.log(t)) + (math.log(y) + math.log(z))
	else:
		tmp = t_2
	return tmp
function code(x, y, z, t, a)
	t_1 = Float64(Float64(Float64(log(z) + log(Float64(y + x))) - t) - Float64(Float64(0.5 - a) * log(t)))
	t_2 = Float64(Float64(Float64(log(t) * a) + log(y)) - t)
	tmp = 0.0
	if (t_1 <= -1000000.0)
		tmp = t_2;
	elseif (t_1 <= 2000.0)
		tmp = Float64(Float64(-0.5 * log(t)) + Float64(log(y) + log(z)));
	else
		tmp = t_2;
	end
	return tmp
end
function tmp_2 = code(x, y, z, t, a)
	t_1 = ((log(z) + log((y + x))) - t) - ((0.5 - a) * log(t));
	t_2 = ((log(t) * a) + log(y)) - t;
	tmp = 0.0;
	if (t_1 <= -1000000.0)
		tmp = t_2;
	elseif (t_1 <= 2000.0)
		tmp = (-0.5 * log(t)) + (log(y) + log(z));
	else
		tmp = t_2;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[(N[(N[Log[z], $MachinePrecision] + N[Log[N[(y + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision] - N[(N[(0.5 - a), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]}, If[LessEqual[t$95$1, -1000000.0], t$95$2, If[LessEqual[t$95$1, 2000.0], N[(N[(-0.5 * N[Log[t], $MachinePrecision]), $MachinePrecision] + N[(N[Log[y], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$2]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t\\
t_2 := \left(\log t \cdot a + \log y\right) - t\\
\mathbf{if}\;t\_1 \leq -1000000:\\
\;\;\;\;t\_2\\

\mathbf{elif}\;t\_1 \leq 2000:\\
\;\;\;\;-0.5 \cdot \log t + \left(\log y + \log z\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (-.f64 (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) t) (*.f64 (-.f64 a #s(literal 1/2 binary64)) (log.f64 t))) < -1e6 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 99.9%

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - \left(t - \left(a - \frac{1}{2}\right) \cdot \log t\right) \]
      15. lower--.f6481.1

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

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

        \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - \frac{1}{2}\right)}\right) \]
      18. lower-*.f6481.1

        \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
    4. Applied rewrites81.1%

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

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

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

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

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

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

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

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

        \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
    7. Applied rewrites75.2%

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

      \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
    9. Step-by-step derivation
      1. Applied rewrites75.0%

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

      if -1e6 < (+.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 99.3%

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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \left(\log \color{blue}{\left(y + x\right)} + \log z\right) + \log t \cdot \frac{-1}{2} \]
        6. lower-log.f6494.7

          \[\leadsto \left(\log \left(y + x\right) + \color{blue}{\log z}\right) + \log t \cdot -0.5 \]
      8. Applied rewrites94.7%

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

        \[\leadsto \left(-1 \cdot \log \left(\frac{1}{y}\right) + \log \color{blue}{z}\right) + \log t \cdot \frac{-1}{2} \]
      10. Step-by-step derivation
        1. Applied rewrites55.7%

          \[\leadsto \left(\log y + \log \color{blue}{z}\right) + \log t \cdot -0.5 \]
      11. Recombined 2 regimes into one program.
      12. Final simplification71.1%

        \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t \leq -1000000:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \mathbf{elif}\;\left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t \leq 2000:\\ \;\;\;\;-0.5 \cdot \log t + \left(\log y + \log z\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \end{array} \]
      13. Add Preprocessing

      Alternative 3: 73.7% accurate, 0.4× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t\\ t_2 := \left(\log t \cdot a + \log y\right) - t\\ \mathbf{if}\;t\_1 \leq -500:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq 950:\\ \;\;\;\;\mathsf{fma}\left(\log t, -0.5, \log \left(\left(y + x\right) \cdot z\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \end{array} \]
      (FPCore (x y z t a)
       :precision binary64
       (let* ((t_1 (- (- (+ (log z) (log (+ y x))) t) (* (- 0.5 a) (log t))))
              (t_2 (- (+ (* (log t) a) (log y)) t)))
         (if (<= t_1 -500.0)
           t_2
           (if (<= t_1 950.0) (- (fma (log t) -0.5 (log (* (+ y x) z))) t) t_2))))
      double code(double x, double y, double z, double t, double a) {
      	double t_1 = ((log(z) + log((y + x))) - t) - ((0.5 - a) * log(t));
      	double t_2 = ((log(t) * a) + log(y)) - t;
      	double tmp;
      	if (t_1 <= -500.0) {
      		tmp = t_2;
      	} else if (t_1 <= 950.0) {
      		tmp = fma(log(t), -0.5, log(((y + x) * z))) - t;
      	} else {
      		tmp = t_2;
      	}
      	return tmp;
      }
      
      function code(x, y, z, t, a)
      	t_1 = Float64(Float64(Float64(log(z) + log(Float64(y + x))) - t) - Float64(Float64(0.5 - a) * log(t)))
      	t_2 = Float64(Float64(Float64(log(t) * a) + log(y)) - t)
      	tmp = 0.0
      	if (t_1 <= -500.0)
      		tmp = t_2;
      	elseif (t_1 <= 950.0)
      		tmp = Float64(fma(log(t), -0.5, log(Float64(Float64(y + x) * z))) - t);
      	else
      		tmp = t_2;
      	end
      	return tmp
      end
      
      code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[(N[(N[Log[z], $MachinePrecision] + N[Log[N[(y + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision] - N[(N[(0.5 - a), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]}, If[LessEqual[t$95$1, -500.0], t$95$2, If[LessEqual[t$95$1, 950.0], N[(N[(N[Log[t], $MachinePrecision] * -0.5 + N[Log[N[(N[(y + x), $MachinePrecision] * z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision], t$95$2]]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      t_1 := \left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t\\
      t_2 := \left(\log t \cdot a + \log y\right) - t\\
      \mathbf{if}\;t\_1 \leq -500:\\
      \;\;\;\;t\_2\\
      
      \mathbf{elif}\;t\_1 \leq 950:\\
      \;\;\;\;\mathsf{fma}\left(\log t, -0.5, \log \left(\left(y + x\right) \cdot z\right)\right) - t\\
      
      \mathbf{else}:\\
      \;\;\;\;t\_2\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (+.f64 (-.f64 (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) t) (*.f64 (-.f64 a #s(literal 1/2 binary64)) (log.f64 t))) < -500 or 950 < (+.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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - \left(t - \left(a - \frac{1}{2}\right) \cdot \log t\right) \]
          15. lower--.f6476.8

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

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

            \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - \frac{1}{2}\right)}\right) \]
          18. lower-*.f6476.8

            \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
        4. Applied rewrites76.8%

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

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

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

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

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

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

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

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

            \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
        7. Applied rewrites74.2%

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

          \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
        9. Step-by-step derivation
          1. Applied rewrites71.5%

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

          if -500 < (+.f64 (-.f64 (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) t) (*.f64 (-.f64 a #s(literal 1/2 binary64)) (log.f64 t))) < 950

          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. 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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - \left(t - \left(a - \frac{1}{2}\right) \cdot \log t\right) \]
            15. lower--.f6493.3

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

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

              \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - \frac{1}{2}\right)}\right) \]
            18. lower-*.f6493.3

              \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
          4. Applied rewrites93.3%

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \mathsf{fma}\left(\log t, \frac{-1}{2}, \log \left(\color{blue}{\left(y + x\right)} \cdot z\right)\right) - t \]
            10. lower-+.f6493.3

              \[\leadsto \mathsf{fma}\left(\log t, -0.5, \log \left(\color{blue}{\left(y + x\right)} \cdot z\right)\right) - t \]
          7. Applied rewrites93.3%

            \[\leadsto \color{blue}{\mathsf{fma}\left(\log t, -0.5, \log \left(\left(y + x\right) \cdot z\right)\right) - t} \]
        10. Recombined 2 regimes into one program.
        11. Final simplification74.9%

          \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t \leq -500:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \mathbf{elif}\;\left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t \leq 950:\\ \;\;\;\;\mathsf{fma}\left(\log t, -0.5, \log \left(\left(y + x\right) \cdot z\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \end{array} \]
        12. Add Preprocessing

        Alternative 4: 64.9% accurate, 0.4× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t\\ t_2 := \left(\log t \cdot a + \log y\right) - t\\ \mathbf{if}\;t\_1 \leq -500:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq 950:\\ \;\;\;\;\log \left(z \cdot y\right) - \left(t - -0.5 \cdot \log t\right)\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \end{array} \]
        (FPCore (x y z t a)
         :precision binary64
         (let* ((t_1 (- (- (+ (log z) (log (+ y x))) t) (* (- 0.5 a) (log t))))
                (t_2 (- (+ (* (log t) a) (log y)) t)))
           (if (<= t_1 -500.0)
             t_2
             (if (<= t_1 950.0) (- (log (* z y)) (- t (* -0.5 (log t)))) t_2))))
        double code(double x, double y, double z, double t, double a) {
        	double t_1 = ((log(z) + log((y + x))) - t) - ((0.5 - a) * log(t));
        	double t_2 = ((log(t) * a) + log(y)) - t;
        	double tmp;
        	if (t_1 <= -500.0) {
        		tmp = t_2;
        	} else if (t_1 <= 950.0) {
        		tmp = log((z * y)) - (t - (-0.5 * log(t)));
        	} else {
        		tmp = t_2;
        	}
        	return tmp;
        }
        
        real(8) function code(x, y, z, t, a)
            real(8), intent (in) :: x
            real(8), intent (in) :: y
            real(8), intent (in) :: z
            real(8), intent (in) :: t
            real(8), intent (in) :: a
            real(8) :: t_1
            real(8) :: t_2
            real(8) :: tmp
            t_1 = ((log(z) + log((y + x))) - t) - ((0.5d0 - a) * log(t))
            t_2 = ((log(t) * a) + log(y)) - t
            if (t_1 <= (-500.0d0)) then
                tmp = t_2
            else if (t_1 <= 950.0d0) then
                tmp = log((z * y)) - (t - ((-0.5d0) * log(t)))
            else
                tmp = t_2
            end if
            code = tmp
        end function
        
        public static double code(double x, double y, double z, double t, double a) {
        	double t_1 = ((Math.log(z) + Math.log((y + x))) - t) - ((0.5 - a) * Math.log(t));
        	double t_2 = ((Math.log(t) * a) + Math.log(y)) - t;
        	double tmp;
        	if (t_1 <= -500.0) {
        		tmp = t_2;
        	} else if (t_1 <= 950.0) {
        		tmp = Math.log((z * y)) - (t - (-0.5 * Math.log(t)));
        	} else {
        		tmp = t_2;
        	}
        	return tmp;
        }
        
        def code(x, y, z, t, a):
        	t_1 = ((math.log(z) + math.log((y + x))) - t) - ((0.5 - a) * math.log(t))
        	t_2 = ((math.log(t) * a) + math.log(y)) - t
        	tmp = 0
        	if t_1 <= -500.0:
        		tmp = t_2
        	elif t_1 <= 950.0:
        		tmp = math.log((z * y)) - (t - (-0.5 * math.log(t)))
        	else:
        		tmp = t_2
        	return tmp
        
        function code(x, y, z, t, a)
        	t_1 = Float64(Float64(Float64(log(z) + log(Float64(y + x))) - t) - Float64(Float64(0.5 - a) * log(t)))
        	t_2 = Float64(Float64(Float64(log(t) * a) + log(y)) - t)
        	tmp = 0.0
        	if (t_1 <= -500.0)
        		tmp = t_2;
        	elseif (t_1 <= 950.0)
        		tmp = Float64(log(Float64(z * y)) - Float64(t - Float64(-0.5 * log(t))));
        	else
        		tmp = t_2;
        	end
        	return tmp
        end
        
        function tmp_2 = code(x, y, z, t, a)
        	t_1 = ((log(z) + log((y + x))) - t) - ((0.5 - a) * log(t));
        	t_2 = ((log(t) * a) + log(y)) - t;
        	tmp = 0.0;
        	if (t_1 <= -500.0)
        		tmp = t_2;
        	elseif (t_1 <= 950.0)
        		tmp = log((z * y)) - (t - (-0.5 * log(t)));
        	else
        		tmp = t_2;
        	end
        	tmp_2 = tmp;
        end
        
        code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[(N[(N[Log[z], $MachinePrecision] + N[Log[N[(y + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision] - N[(N[(0.5 - a), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]}, If[LessEqual[t$95$1, -500.0], t$95$2, If[LessEqual[t$95$1, 950.0], N[(N[Log[N[(z * y), $MachinePrecision]], $MachinePrecision] - N[(t - N[(-0.5 * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$2]]]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        t_1 := \left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t\\
        t_2 := \left(\log t \cdot a + \log y\right) - t\\
        \mathbf{if}\;t\_1 \leq -500:\\
        \;\;\;\;t\_2\\
        
        \mathbf{elif}\;t\_1 \leq 950:\\
        \;\;\;\;\log \left(z \cdot y\right) - \left(t - -0.5 \cdot \log t\right)\\
        
        \mathbf{else}:\\
        \;\;\;\;t\_2\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if (+.f64 (-.f64 (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) t) (*.f64 (-.f64 a #s(literal 1/2 binary64)) (log.f64 t))) < -500 or 950 < (+.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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - \left(t - \left(a - \frac{1}{2}\right) \cdot \log t\right) \]
            15. lower--.f6476.8

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

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

              \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - \frac{1}{2}\right)}\right) \]
            18. lower-*.f6476.8

              \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
          4. Applied rewrites76.8%

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

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

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

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

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

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

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

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

              \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
          7. Applied rewrites74.2%

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

            \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
          9. Step-by-step derivation
            1. Applied rewrites71.5%

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

            if -500 < (+.f64 (-.f64 (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) t) (*.f64 (-.f64 a #s(literal 1/2 binary64)) (log.f64 t))) < 950

            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. 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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

                \[\leadsto \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - \left(t - \left(a - \frac{1}{2}\right) \cdot \log t\right) \]
              15. lower--.f6493.3

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

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

                \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - \frac{1}{2}\right)}\right) \]
              18. lower-*.f6493.3

                \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
            4. Applied rewrites93.3%

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

              \[\leadsto \log \color{blue}{\left(y \cdot z\right)} - \left(t - \log t \cdot \left(a - \frac{1}{2}\right)\right) \]
            6. Step-by-step derivation
              1. lower-*.f6458.5

                \[\leadsto \log \color{blue}{\left(y \cdot z\right)} - \left(t - \log t \cdot \left(a - 0.5\right)\right) \]
            7. Applied rewrites58.5%

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

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

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

                \[\leadsto \log \left(y \cdot z\right) - \left(t - \color{blue}{\log t \cdot \frac{-1}{2}}\right) \]
              3. lower-log.f6458.5

                \[\leadsto \log \left(y \cdot z\right) - \left(t - \color{blue}{\log t} \cdot -0.5\right) \]
            10. Applied rewrites58.5%

              \[\leadsto \log \left(y \cdot z\right) - \left(t - \color{blue}{\log t \cdot -0.5}\right) \]
          10. Recombined 2 regimes into one program.
          11. Final simplification69.4%

            \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t \leq -500:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \mathbf{elif}\;\left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t \leq 950:\\ \;\;\;\;\log \left(z \cdot y\right) - \left(t - -0.5 \cdot \log t\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \end{array} \]
          12. Add Preprocessing

          Alternative 5: 64.9% accurate, 0.4× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t\\ t_2 := \left(\log t \cdot a + \log y\right) - t\\ \mathbf{if}\;t\_1 \leq -500:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq 950:\\ \;\;\;\;\mathsf{fma}\left(\log t, -0.5, \log \left(z \cdot y\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \end{array} \]
          (FPCore (x y z t a)
           :precision binary64
           (let* ((t_1 (- (- (+ (log z) (log (+ y x))) t) (* (- 0.5 a) (log t))))
                  (t_2 (- (+ (* (log t) a) (log y)) t)))
             (if (<= t_1 -500.0)
               t_2
               (if (<= t_1 950.0) (- (fma (log t) -0.5 (log (* z y))) t) t_2))))
          double code(double x, double y, double z, double t, double a) {
          	double t_1 = ((log(z) + log((y + x))) - t) - ((0.5 - a) * log(t));
          	double t_2 = ((log(t) * a) + log(y)) - t;
          	double tmp;
          	if (t_1 <= -500.0) {
          		tmp = t_2;
          	} else if (t_1 <= 950.0) {
          		tmp = fma(log(t), -0.5, log((z * y))) - t;
          	} else {
          		tmp = t_2;
          	}
          	return tmp;
          }
          
          function code(x, y, z, t, a)
          	t_1 = Float64(Float64(Float64(log(z) + log(Float64(y + x))) - t) - Float64(Float64(0.5 - a) * log(t)))
          	t_2 = Float64(Float64(Float64(log(t) * a) + log(y)) - t)
          	tmp = 0.0
          	if (t_1 <= -500.0)
          		tmp = t_2;
          	elseif (t_1 <= 950.0)
          		tmp = Float64(fma(log(t), -0.5, log(Float64(z * y))) - t);
          	else
          		tmp = t_2;
          	end
          	return tmp
          end
          
          code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[(N[(N[Log[z], $MachinePrecision] + N[Log[N[(y + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision] - N[(N[(0.5 - a), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]}, If[LessEqual[t$95$1, -500.0], t$95$2, If[LessEqual[t$95$1, 950.0], N[(N[(N[Log[t], $MachinePrecision] * -0.5 + N[Log[N[(z * y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision], t$95$2]]]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          t_1 := \left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t\\
          t_2 := \left(\log t \cdot a + \log y\right) - t\\
          \mathbf{if}\;t\_1 \leq -500:\\
          \;\;\;\;t\_2\\
          
          \mathbf{elif}\;t\_1 \leq 950:\\
          \;\;\;\;\mathsf{fma}\left(\log t, -0.5, \log \left(z \cdot y\right)\right) - t\\
          
          \mathbf{else}:\\
          \;\;\;\;t\_2\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if (+.f64 (-.f64 (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) t) (*.f64 (-.f64 a #s(literal 1/2 binary64)) (log.f64 t))) < -500 or 950 < (+.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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

                \[\leadsto \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - \left(t - \left(a - \frac{1}{2}\right) \cdot \log t\right) \]
              15. lower--.f6476.8

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

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

                \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - \frac{1}{2}\right)}\right) \]
              18. lower-*.f6476.8

                \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
            4. Applied rewrites76.8%

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

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

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

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

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

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

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

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

                \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
            7. Applied rewrites74.2%

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

              \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
            9. Step-by-step derivation
              1. Applied rewrites71.5%

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

              if -500 < (+.f64 (-.f64 (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) t) (*.f64 (-.f64 a #s(literal 1/2 binary64)) (log.f64 t))) < 950

              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. 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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

                  \[\leadsto \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - \left(t - \left(a - \frac{1}{2}\right) \cdot \log t\right) \]
                15. lower--.f6493.3

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

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

                  \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - \frac{1}{2}\right)}\right) \]
                18. lower-*.f6493.3

                  \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
              4. Applied rewrites93.3%

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

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

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

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

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

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

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

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

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

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

                  \[\leadsto \mathsf{fma}\left(\log t, \frac{-1}{2}, \log \left(\color{blue}{\left(y + x\right)} \cdot z\right)\right) - t \]
                10. lower-+.f6493.3

                  \[\leadsto \mathsf{fma}\left(\log t, -0.5, \log \left(\color{blue}{\left(y + x\right)} \cdot z\right)\right) - t \]
              7. Applied rewrites93.3%

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

                \[\leadsto \mathsf{fma}\left(\log t, \frac{-1}{2}, \log \left(y \cdot z\right)\right) - t \]
              9. Step-by-step derivation
                1. Applied rewrites58.5%

                  \[\leadsto \mathsf{fma}\left(\log t, -0.5, \log \left(y \cdot z\right)\right) - t \]
              10. Recombined 2 regimes into one program.
              11. Final simplification69.4%

                \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t \leq -500:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \mathbf{elif}\;\left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t \leq 950:\\ \;\;\;\;\mathsf{fma}\left(\log t, -0.5, \log \left(z \cdot y\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \end{array} \]
              12. Add Preprocessing

              Alternative 6: 73.4% accurate, 0.4× speedup?

              \[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t\\ t_2 := \left(\log t \cdot a + \log y\right) - t\\ \mathbf{if}\;t\_1 \leq -500:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq 950:\\ \;\;\;\;\mathsf{fma}\left(\log t, -0.5, \log \left(\left(y + x\right) \cdot z\right)\right)\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \end{array} \]
              (FPCore (x y z t a)
               :precision binary64
               (let* ((t_1 (- (- (+ (log z) (log (+ y x))) t) (* (- 0.5 a) (log t))))
                      (t_2 (- (+ (* (log t) a) (log y)) t)))
                 (if (<= t_1 -500.0)
                   t_2
                   (if (<= t_1 950.0) (fma (log t) -0.5 (log (* (+ y x) z))) t_2))))
              double code(double x, double y, double z, double t, double a) {
              	double t_1 = ((log(z) + log((y + x))) - t) - ((0.5 - a) * log(t));
              	double t_2 = ((log(t) * a) + log(y)) - t;
              	double tmp;
              	if (t_1 <= -500.0) {
              		tmp = t_2;
              	} else if (t_1 <= 950.0) {
              		tmp = fma(log(t), -0.5, log(((y + x) * z)));
              	} else {
              		tmp = t_2;
              	}
              	return tmp;
              }
              
              function code(x, y, z, t, a)
              	t_1 = Float64(Float64(Float64(log(z) + log(Float64(y + x))) - t) - Float64(Float64(0.5 - a) * log(t)))
              	t_2 = Float64(Float64(Float64(log(t) * a) + log(y)) - t)
              	tmp = 0.0
              	if (t_1 <= -500.0)
              		tmp = t_2;
              	elseif (t_1 <= 950.0)
              		tmp = fma(log(t), -0.5, log(Float64(Float64(y + x) * z)));
              	else
              		tmp = t_2;
              	end
              	return tmp
              end
              
              code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[(N[(N[Log[z], $MachinePrecision] + N[Log[N[(y + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision] - N[(N[(0.5 - a), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]}, If[LessEqual[t$95$1, -500.0], t$95$2, If[LessEqual[t$95$1, 950.0], N[(N[Log[t], $MachinePrecision] * -0.5 + N[Log[N[(N[(y + x), $MachinePrecision] * z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], t$95$2]]]]
              
              \begin{array}{l}
              
              \\
              \begin{array}{l}
              t_1 := \left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t\\
              t_2 := \left(\log t \cdot a + \log y\right) - t\\
              \mathbf{if}\;t\_1 \leq -500:\\
              \;\;\;\;t\_2\\
              
              \mathbf{elif}\;t\_1 \leq 950:\\
              \;\;\;\;\mathsf{fma}\left(\log t, -0.5, \log \left(\left(y + x\right) \cdot z\right)\right)\\
              
              \mathbf{else}:\\
              \;\;\;\;t\_2\\
              
              
              \end{array}
              \end{array}
              
              Derivation
              1. Split input into 2 regimes
              2. if (+.f64 (-.f64 (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) t) (*.f64 (-.f64 a #s(literal 1/2 binary64)) (log.f64 t))) < -500 or 950 < (+.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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

                    \[\leadsto \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - \left(t - \left(a - \frac{1}{2}\right) \cdot \log t\right) \]
                  15. lower--.f6476.8

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

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

                    \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - \frac{1}{2}\right)}\right) \]
                  18. lower-*.f6476.8

                    \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
                4. Applied rewrites76.8%

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

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

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

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

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

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

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

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

                    \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                7. Applied rewrites74.2%

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

                  \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
                9. Step-by-step derivation
                  1. Applied rewrites71.5%

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

                  if -500 < (+.f64 (-.f64 (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) t) (*.f64 (-.f64 a #s(literal 1/2 binary64)) (log.f64 t))) < 950

                  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. 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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

                      \[\leadsto \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - \left(t - \left(a - \frac{1}{2}\right) \cdot \log t\right) \]
                    15. lower--.f6493.3

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

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

                      \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - \frac{1}{2}\right)}\right) \]
                    18. lower-*.f6493.3

                      \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
                  4. Applied rewrites93.3%

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

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

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

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

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

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

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

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

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

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

                      \[\leadsto \mathsf{fma}\left(\log t, \frac{-1}{2}, \log \left(\color{blue}{\left(y + x\right)} \cdot z\right)\right) - t \]
                    10. lower-+.f6493.3

                      \[\leadsto \mathsf{fma}\left(\log t, -0.5, \log \left(\color{blue}{\left(y + x\right)} \cdot z\right)\right) - t \]
                  7. Applied rewrites93.3%

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

                    \[\leadsto \log \left(z \cdot \left(x + y\right)\right) + \color{blue}{\frac{-1}{2} \cdot \log t} \]
                  9. Step-by-step derivation
                    1. Applied rewrites87.2%

                      \[\leadsto \mathsf{fma}\left(\log t, \color{blue}{-0.5}, \log \left(\left(y + x\right) \cdot z\right)\right) \]
                  10. Recombined 2 regimes into one program.
                  11. Final simplification73.9%

                    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t \leq -500:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \mathbf{elif}\;\left(\left(\log z + \log \left(y + x\right)\right) - t\right) - \left(0.5 - a\right) \cdot \log t \leq 950:\\ \;\;\;\;\mathsf{fma}\left(\log t, -0.5, \log \left(\left(y + x\right) \cdot z\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \end{array} \]
                  12. Add Preprocessing

                  Alternative 7: 89.1% accurate, 0.5× speedup?

                  \[\begin{array}{l} \\ \begin{array}{l} t_1 := \log z + \log \left(y + x\right)\\ t_2 := \left(\log t \cdot a + \log y\right) - t\\ \mathbf{if}\;t\_1 \leq -750:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq 700:\\ \;\;\;\;\log \left(\left(y + x\right) \cdot z\right) - \left(t - \log t \cdot \left(a - 0.5\right)\right)\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \end{array} \]
                  (FPCore (x y z t a)
                   :precision binary64
                   (let* ((t_1 (+ (log z) (log (+ y x)))) (t_2 (- (+ (* (log t) a) (log y)) t)))
                     (if (<= t_1 -750.0)
                       t_2
                       (if (<= t_1 700.0)
                         (- (log (* (+ y x) z)) (- t (* (log t) (- a 0.5))))
                         t_2))))
                  double code(double x, double y, double z, double t, double a) {
                  	double t_1 = log(z) + log((y + x));
                  	double t_2 = ((log(t) * a) + log(y)) - t;
                  	double tmp;
                  	if (t_1 <= -750.0) {
                  		tmp = t_2;
                  	} else if (t_1 <= 700.0) {
                  		tmp = log(((y + x) * z)) - (t - (log(t) * (a - 0.5)));
                  	} else {
                  		tmp = t_2;
                  	}
                  	return tmp;
                  }
                  
                  real(8) function code(x, y, z, t, a)
                      real(8), intent (in) :: x
                      real(8), intent (in) :: y
                      real(8), intent (in) :: z
                      real(8), intent (in) :: t
                      real(8), intent (in) :: a
                      real(8) :: t_1
                      real(8) :: t_2
                      real(8) :: tmp
                      t_1 = log(z) + log((y + x))
                      t_2 = ((log(t) * a) + log(y)) - t
                      if (t_1 <= (-750.0d0)) then
                          tmp = t_2
                      else if (t_1 <= 700.0d0) then
                          tmp = log(((y + x) * z)) - (t - (log(t) * (a - 0.5d0)))
                      else
                          tmp = t_2
                      end if
                      code = tmp
                  end function
                  
                  public static double code(double x, double y, double z, double t, double a) {
                  	double t_1 = Math.log(z) + Math.log((y + x));
                  	double t_2 = ((Math.log(t) * a) + Math.log(y)) - t;
                  	double tmp;
                  	if (t_1 <= -750.0) {
                  		tmp = t_2;
                  	} else if (t_1 <= 700.0) {
                  		tmp = Math.log(((y + x) * z)) - (t - (Math.log(t) * (a - 0.5)));
                  	} else {
                  		tmp = t_2;
                  	}
                  	return tmp;
                  }
                  
                  def code(x, y, z, t, a):
                  	t_1 = math.log(z) + math.log((y + x))
                  	t_2 = ((math.log(t) * a) + math.log(y)) - t
                  	tmp = 0
                  	if t_1 <= -750.0:
                  		tmp = t_2
                  	elif t_1 <= 700.0:
                  		tmp = math.log(((y + x) * z)) - (t - (math.log(t) * (a - 0.5)))
                  	else:
                  		tmp = t_2
                  	return tmp
                  
                  function code(x, y, z, t, a)
                  	t_1 = Float64(log(z) + log(Float64(y + x)))
                  	t_2 = Float64(Float64(Float64(log(t) * a) + log(y)) - t)
                  	tmp = 0.0
                  	if (t_1 <= -750.0)
                  		tmp = t_2;
                  	elseif (t_1 <= 700.0)
                  		tmp = Float64(log(Float64(Float64(y + x) * z)) - Float64(t - Float64(log(t) * Float64(a - 0.5))));
                  	else
                  		tmp = t_2;
                  	end
                  	return tmp
                  end
                  
                  function tmp_2 = code(x, y, z, t, a)
                  	t_1 = log(z) + log((y + x));
                  	t_2 = ((log(t) * a) + log(y)) - t;
                  	tmp = 0.0;
                  	if (t_1 <= -750.0)
                  		tmp = t_2;
                  	elseif (t_1 <= 700.0)
                  		tmp = log(((y + x) * z)) - (t - (log(t) * (a - 0.5)));
                  	else
                  		tmp = t_2;
                  	end
                  	tmp_2 = tmp;
                  end
                  
                  code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[Log[z], $MachinePrecision] + N[Log[N[(y + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]}, If[LessEqual[t$95$1, -750.0], t$95$2, If[LessEqual[t$95$1, 700.0], N[(N[Log[N[(N[(y + x), $MachinePrecision] * z), $MachinePrecision]], $MachinePrecision] - N[(t - N[(N[Log[t], $MachinePrecision] * N[(a - 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$2]]]]
                  
                  \begin{array}{l}
                  
                  \\
                  \begin{array}{l}
                  t_1 := \log z + \log \left(y + x\right)\\
                  t_2 := \left(\log t \cdot a + \log y\right) - t\\
                  \mathbf{if}\;t\_1 \leq -750:\\
                  \;\;\;\;t\_2\\
                  
                  \mathbf{elif}\;t\_1 \leq 700:\\
                  \;\;\;\;\log \left(\left(y + x\right) \cdot z\right) - \left(t - \log t \cdot \left(a - 0.5\right)\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 700 < (+.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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

                        \[\leadsto \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - \left(t - \left(a - \frac{1}{2}\right) \cdot \log t\right) \]
                      15. lower--.f645.7

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

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

                        \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - \frac{1}{2}\right)}\right) \]
                      18. lower-*.f645.7

                        \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
                    4. Applied rewrites5.7%

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

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

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

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

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

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

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

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

                        \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                    7. Applied rewrites71.4%

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

                      \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
                    9. Step-by-step derivation
                      1. Applied rewrites61.4%

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

                      if -750 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < 700

                      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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                          \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
                      4. Applied rewrites99.5%

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

                      \[\leadsto \begin{array}{l} \mathbf{if}\;\log z + \log \left(y + x\right) \leq -750:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \mathbf{elif}\;\log z + \log \left(y + x\right) \leq 700:\\ \;\;\;\;\log \left(\left(y + x\right) \cdot z\right) - \left(t - \log t \cdot \left(a - 0.5\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \end{array} \]
                    12. Add Preprocessing

                    Alternative 8: 89.1% accurate, 0.5× speedup?

                    \[\begin{array}{l} \\ \begin{array}{l} t_1 := \log z + \log \left(y + x\right)\\ t_2 := \left(\log t \cdot a + \log y\right) - t\\ \mathbf{if}\;t\_1 \leq -750:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq 700:\\ \;\;\;\;\mathsf{fma}\left(\log t, a - 0.5, \log \left(\left(y + x\right) \cdot z\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \end{array} \]
                    (FPCore (x y z t a)
                     :precision binary64
                     (let* ((t_1 (+ (log z) (log (+ y x)))) (t_2 (- (+ (* (log t) a) (log y)) t)))
                       (if (<= t_1 -750.0)
                         t_2
                         (if (<= t_1 700.0)
                           (- (fma (log t) (- a 0.5) (log (* (+ y x) z))) t)
                           t_2))))
                    double code(double x, double y, double z, double t, double a) {
                    	double t_1 = log(z) + log((y + x));
                    	double t_2 = ((log(t) * a) + log(y)) - t;
                    	double tmp;
                    	if (t_1 <= -750.0) {
                    		tmp = t_2;
                    	} else if (t_1 <= 700.0) {
                    		tmp = fma(log(t), (a - 0.5), log(((y + x) * z))) - t;
                    	} else {
                    		tmp = t_2;
                    	}
                    	return tmp;
                    }
                    
                    function code(x, y, z, t, a)
                    	t_1 = Float64(log(z) + log(Float64(y + x)))
                    	t_2 = Float64(Float64(Float64(log(t) * a) + log(y)) - t)
                    	tmp = 0.0
                    	if (t_1 <= -750.0)
                    		tmp = t_2;
                    	elseif (t_1 <= 700.0)
                    		tmp = Float64(fma(log(t), Float64(a - 0.5), log(Float64(Float64(y + x) * z))) - t);
                    	else
                    		tmp = t_2;
                    	end
                    	return tmp
                    end
                    
                    code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[Log[z], $MachinePrecision] + N[Log[N[(y + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]}, If[LessEqual[t$95$1, -750.0], t$95$2, If[LessEqual[t$95$1, 700.0], N[(N[(N[Log[t], $MachinePrecision] * N[(a - 0.5), $MachinePrecision] + N[Log[N[(N[(y + x), $MachinePrecision] * z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision], t$95$2]]]]
                    
                    \begin{array}{l}
                    
                    \\
                    \begin{array}{l}
                    t_1 := \log z + \log \left(y + x\right)\\
                    t_2 := \left(\log t \cdot a + \log y\right) - t\\
                    \mathbf{if}\;t\_1 \leq -750:\\
                    \;\;\;\;t\_2\\
                    
                    \mathbf{elif}\;t\_1 \leq 700:\\
                    \;\;\;\;\mathsf{fma}\left(\log t, a - 0.5, \log \left(\left(y + x\right) \cdot z\right)\right) - t\\
                    
                    \mathbf{else}:\\
                    \;\;\;\;t\_2\\
                    
                    
                    \end{array}
                    \end{array}
                    
                    Derivation
                    1. Split input into 2 regimes
                    2. if (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < -750 or 700 < (+.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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

                          \[\leadsto \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - \left(t - \left(a - \frac{1}{2}\right) \cdot \log t\right) \]
                        15. lower--.f645.7

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

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

                          \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - \frac{1}{2}\right)}\right) \]
                        18. lower-*.f645.7

                          \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
                      4. Applied rewrites5.7%

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

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

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

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

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

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

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

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

                          \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                      7. Applied rewrites71.4%

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

                        \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
                      9. Step-by-step derivation
                        1. Applied rewrites61.4%

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

                        if -750 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < 700

                        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. +-commutativeN/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                        \[\leadsto \begin{array}{l} \mathbf{if}\;\log z + \log \left(y + x\right) \leq -750:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \mathbf{elif}\;\log z + \log \left(y + x\right) \leq 700:\\ \;\;\;\;\mathsf{fma}\left(\log t, a - 0.5, \log \left(\left(y + x\right) \cdot z\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \end{array} \]
                      12. Add Preprocessing

                      Alternative 9: 63.7% accurate, 0.5× speedup?

                      \[\begin{array}{l} \\ \begin{array}{l} t_1 := \log z + \log \left(y + x\right)\\ t_2 := \left(\log t \cdot a + \log y\right) - t\\ \mathbf{if}\;t\_1 \leq -750:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq 700:\\ \;\;\;\;\log \left(z \cdot y\right) - \left(t - \log t \cdot \left(a - 0.5\right)\right)\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \end{array} \]
                      (FPCore (x y z t a)
                       :precision binary64
                       (let* ((t_1 (+ (log z) (log (+ y x)))) (t_2 (- (+ (* (log t) a) (log y)) t)))
                         (if (<= t_1 -750.0)
                           t_2
                           (if (<= t_1 700.0) (- (log (* z y)) (- t (* (log t) (- a 0.5)))) t_2))))
                      double code(double x, double y, double z, double t, double a) {
                      	double t_1 = log(z) + log((y + x));
                      	double t_2 = ((log(t) * a) + log(y)) - t;
                      	double tmp;
                      	if (t_1 <= -750.0) {
                      		tmp = t_2;
                      	} else if (t_1 <= 700.0) {
                      		tmp = log((z * y)) - (t - (log(t) * (a - 0.5)));
                      	} else {
                      		tmp = t_2;
                      	}
                      	return tmp;
                      }
                      
                      real(8) function code(x, y, z, t, a)
                          real(8), intent (in) :: x
                          real(8), intent (in) :: y
                          real(8), intent (in) :: z
                          real(8), intent (in) :: t
                          real(8), intent (in) :: a
                          real(8) :: t_1
                          real(8) :: t_2
                          real(8) :: tmp
                          t_1 = log(z) + log((y + x))
                          t_2 = ((log(t) * a) + log(y)) - t
                          if (t_1 <= (-750.0d0)) then
                              tmp = t_2
                          else if (t_1 <= 700.0d0) then
                              tmp = log((z * y)) - (t - (log(t) * (a - 0.5d0)))
                          else
                              tmp = t_2
                          end if
                          code = tmp
                      end function
                      
                      public static double code(double x, double y, double z, double t, double a) {
                      	double t_1 = Math.log(z) + Math.log((y + x));
                      	double t_2 = ((Math.log(t) * a) + Math.log(y)) - t;
                      	double tmp;
                      	if (t_1 <= -750.0) {
                      		tmp = t_2;
                      	} else if (t_1 <= 700.0) {
                      		tmp = Math.log((z * y)) - (t - (Math.log(t) * (a - 0.5)));
                      	} else {
                      		tmp = t_2;
                      	}
                      	return tmp;
                      }
                      
                      def code(x, y, z, t, a):
                      	t_1 = math.log(z) + math.log((y + x))
                      	t_2 = ((math.log(t) * a) + math.log(y)) - t
                      	tmp = 0
                      	if t_1 <= -750.0:
                      		tmp = t_2
                      	elif t_1 <= 700.0:
                      		tmp = math.log((z * y)) - (t - (math.log(t) * (a - 0.5)))
                      	else:
                      		tmp = t_2
                      	return tmp
                      
                      function code(x, y, z, t, a)
                      	t_1 = Float64(log(z) + log(Float64(y + x)))
                      	t_2 = Float64(Float64(Float64(log(t) * a) + log(y)) - t)
                      	tmp = 0.0
                      	if (t_1 <= -750.0)
                      		tmp = t_2;
                      	elseif (t_1 <= 700.0)
                      		tmp = Float64(log(Float64(z * y)) - Float64(t - Float64(log(t) * Float64(a - 0.5))));
                      	else
                      		tmp = t_2;
                      	end
                      	return tmp
                      end
                      
                      function tmp_2 = code(x, y, z, t, a)
                      	t_1 = log(z) + log((y + x));
                      	t_2 = ((log(t) * a) + log(y)) - t;
                      	tmp = 0.0;
                      	if (t_1 <= -750.0)
                      		tmp = t_2;
                      	elseif (t_1 <= 700.0)
                      		tmp = log((z * y)) - (t - (log(t) * (a - 0.5)));
                      	else
                      		tmp = t_2;
                      	end
                      	tmp_2 = tmp;
                      end
                      
                      code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[Log[z], $MachinePrecision] + N[Log[N[(y + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]}, If[LessEqual[t$95$1, -750.0], t$95$2, If[LessEqual[t$95$1, 700.0], N[(N[Log[N[(z * y), $MachinePrecision]], $MachinePrecision] - N[(t - N[(N[Log[t], $MachinePrecision] * N[(a - 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$2]]]]
                      
                      \begin{array}{l}
                      
                      \\
                      \begin{array}{l}
                      t_1 := \log z + \log \left(y + x\right)\\
                      t_2 := \left(\log t \cdot a + \log y\right) - t\\
                      \mathbf{if}\;t\_1 \leq -750:\\
                      \;\;\;\;t\_2\\
                      
                      \mathbf{elif}\;t\_1 \leq 700:\\
                      \;\;\;\;\log \left(z \cdot y\right) - \left(t - \log t \cdot \left(a - 0.5\right)\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 700 < (+.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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

                            \[\leadsto \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - \left(t - \left(a - \frac{1}{2}\right) \cdot \log t\right) \]
                          15. lower--.f645.7

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

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

                            \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - \frac{1}{2}\right)}\right) \]
                          18. lower-*.f645.7

                            \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
                        4. Applied rewrites5.7%

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

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

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

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

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

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

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

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

                            \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                        7. Applied rewrites71.4%

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

                          \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
                        9. Step-by-step derivation
                          1. Applied rewrites61.4%

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

                          if -750 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < 700

                          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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                              \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
                          4. Applied rewrites99.5%

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

                            \[\leadsto \log \color{blue}{\left(y \cdot z\right)} - \left(t - \log t \cdot \left(a - \frac{1}{2}\right)\right) \]
                          6. Step-by-step derivation
                            1. lower-*.f6466.2

                              \[\leadsto \log \color{blue}{\left(y \cdot z\right)} - \left(t - \log t \cdot \left(a - 0.5\right)\right) \]
                          7. Applied rewrites66.2%

                            \[\leadsto \log \color{blue}{\left(y \cdot z\right)} - \left(t - \log t \cdot \left(a - 0.5\right)\right) \]
                        10. Recombined 2 regimes into one program.
                        11. Final simplification65.2%

                          \[\leadsto \begin{array}{l} \mathbf{if}\;\log z + \log \left(y + x\right) \leq -750:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \mathbf{elif}\;\log z + \log \left(y + x\right) \leq 700:\\ \;\;\;\;\log \left(z \cdot y\right) - \left(t - \log t \cdot \left(a - 0.5\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \end{array} \]
                        12. Add Preprocessing

                        Alternative 10: 63.7% accurate, 0.5× speedup?

                        \[\begin{array}{l} \\ \begin{array}{l} t_1 := \log z + \log \left(y + x\right)\\ t_2 := \left(\log t \cdot a + \log y\right) - t\\ \mathbf{if}\;t\_1 \leq -750:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq 700:\\ \;\;\;\;\mathsf{fma}\left(-0.5 + a, \log t, \log \left(z \cdot y\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \end{array} \]
                        (FPCore (x y z t a)
                         :precision binary64
                         (let* ((t_1 (+ (log z) (log (+ y x)))) (t_2 (- (+ (* (log t) a) (log y)) t)))
                           (if (<= t_1 -750.0)
                             t_2
                             (if (<= t_1 700.0) (- (fma (+ -0.5 a) (log t) (log (* z y))) t) t_2))))
                        double code(double x, double y, double z, double t, double a) {
                        	double t_1 = log(z) + log((y + x));
                        	double t_2 = ((log(t) * a) + log(y)) - t;
                        	double tmp;
                        	if (t_1 <= -750.0) {
                        		tmp = t_2;
                        	} else if (t_1 <= 700.0) {
                        		tmp = fma((-0.5 + a), log(t), log((z * y))) - t;
                        	} else {
                        		tmp = t_2;
                        	}
                        	return tmp;
                        }
                        
                        function code(x, y, z, t, a)
                        	t_1 = Float64(log(z) + log(Float64(y + x)))
                        	t_2 = Float64(Float64(Float64(log(t) * a) + log(y)) - t)
                        	tmp = 0.0
                        	if (t_1 <= -750.0)
                        		tmp = t_2;
                        	elseif (t_1 <= 700.0)
                        		tmp = Float64(fma(Float64(-0.5 + a), log(t), log(Float64(z * y))) - t);
                        	else
                        		tmp = t_2;
                        	end
                        	return tmp
                        end
                        
                        code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[Log[z], $MachinePrecision] + N[Log[N[(y + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]}, If[LessEqual[t$95$1, -750.0], t$95$2, If[LessEqual[t$95$1, 700.0], N[(N[(N[(-0.5 + a), $MachinePrecision] * N[Log[t], $MachinePrecision] + N[Log[N[(z * y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision], t$95$2]]]]
                        
                        \begin{array}{l}
                        
                        \\
                        \begin{array}{l}
                        t_1 := \log z + \log \left(y + x\right)\\
                        t_2 := \left(\log t \cdot a + \log y\right) - t\\
                        \mathbf{if}\;t\_1 \leq -750:\\
                        \;\;\;\;t\_2\\
                        
                        \mathbf{elif}\;t\_1 \leq 700:\\
                        \;\;\;\;\mathsf{fma}\left(-0.5 + a, \log t, \log \left(z \cdot y\right)\right) - t\\
                        
                        \mathbf{else}:\\
                        \;\;\;\;t\_2\\
                        
                        
                        \end{array}
                        \end{array}
                        
                        Derivation
                        1. Split input into 2 regimes
                        2. if (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < -750 or 700 < (+.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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

                              \[\leadsto \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - \left(t - \left(a - \frac{1}{2}\right) \cdot \log t\right) \]
                            15. lower--.f645.7

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

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

                              \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - \frac{1}{2}\right)}\right) \]
                            18. lower-*.f645.7

                              \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
                          4. Applied rewrites5.7%

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

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

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

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

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

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

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

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

                              \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                          7. Applied rewrites71.4%

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

                            \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
                          9. Step-by-step derivation
                            1. Applied rewrites61.4%

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

                            if -750 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < 700

                            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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                                \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
                            4. Applied rewrites99.5%

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

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

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

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

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

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

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

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

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

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

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

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

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

                                \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \log t, \color{blue}{\log \left(y \cdot z\right)}\right) - t \]
                              13. lower-*.f6466.2

                                \[\leadsto \mathsf{fma}\left(-0.5 + a, \log t, \log \color{blue}{\left(y \cdot z\right)}\right) - t \]
                            7. Applied rewrites66.2%

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

                            \[\leadsto \begin{array}{l} \mathbf{if}\;\log z + \log \left(y + x\right) \leq -750:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \mathbf{elif}\;\log z + \log \left(y + x\right) \leq 700:\\ \;\;\;\;\mathsf{fma}\left(-0.5 + a, \log t, \log \left(z \cdot y\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \end{array} \]
                          12. Add Preprocessing

                          Alternative 11: 68.0% accurate, 1.0× speedup?

                          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq 212:\\ \;\;\;\;\mathsf{fma}\left(-0.5 + a, \log t, \log z\right) + \log y\\ \mathbf{else}:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \end{array} \end{array} \]
                          (FPCore (x y z t a)
                           :precision binary64
                           (if (<= t 212.0)
                             (+ (fma (+ -0.5 a) (log t) (log z)) (log y))
                             (- (+ (* (log t) a) (log y)) t)))
                          double code(double x, double y, double z, double t, double a) {
                          	double tmp;
                          	if (t <= 212.0) {
                          		tmp = fma((-0.5 + a), log(t), log(z)) + log(y);
                          	} else {
                          		tmp = ((log(t) * a) + log(y)) - t;
                          	}
                          	return tmp;
                          }
                          
                          function code(x, y, z, t, a)
                          	tmp = 0.0
                          	if (t <= 212.0)
                          		tmp = Float64(fma(Float64(-0.5 + a), log(t), log(z)) + log(y));
                          	else
                          		tmp = Float64(Float64(Float64(log(t) * a) + log(y)) - t);
                          	end
                          	return tmp
                          end
                          
                          code[x_, y_, z_, t_, a_] := If[LessEqual[t, 212.0], N[(N[(N[(-0.5 + a), $MachinePrecision] * N[Log[t], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]]
                          
                          \begin{array}{l}
                          
                          \\
                          \begin{array}{l}
                          \mathbf{if}\;t \leq 212:\\
                          \;\;\;\;\mathsf{fma}\left(-0.5 + a, \log t, \log z\right) + \log y\\
                          
                          \mathbf{else}:\\
                          \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\
                          
                          
                          \end{array}
                          \end{array}
                          
                          Derivation
                          1. Split input into 2 regimes
                          2. if t < 212

                            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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

                                \[\leadsto \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - \left(t - \left(a - \frac{1}{2}\right) \cdot \log t\right) \]
                              15. lower--.f6477.4

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

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

                                \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - \frac{1}{2}\right)}\right) \]
                              18. lower-*.f6477.4

                                \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
                            4. Applied rewrites77.4%

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

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

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

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

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

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

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

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

                                \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                            7. Applied rewrites68.8%

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

                              \[\leadsto \log y + \color{blue}{\left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)} \]
                            9. Step-by-step derivation
                              1. Applied rewrites67.3%

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

                              if 212 < 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. 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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

                                  \[\leadsto \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - \left(t - \left(a - \frac{1}{2}\right) \cdot \log t\right) \]
                                15. lower--.f6481.2

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

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

                                  \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - \frac{1}{2}\right)}\right) \]
                                18. lower-*.f6481.2

                                  \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
                              4. Applied rewrites81.2%

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

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

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

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

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

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

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

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

                                  \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                              7. Applied rewrites74.9%

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

                                \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
                              9. Step-by-step derivation
                                1. Applied rewrites74.6%

                                  \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
                              10. Recombined 2 regimes into one program.
                              11. Final simplification71.1%

                                \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq 212:\\ \;\;\;\;\mathsf{fma}\left(-0.5 + a, \log t, \log z\right) + \log y\\ \mathbf{else}:\\ \;\;\;\;\left(\log t \cdot a + \log y\right) - t\\ \end{array} \]
                              12. Add Preprocessing

                              Alternative 12: 68.5% accurate, 1.0× speedup?

                              \[\begin{array}{l} \\ \left(\mathsf{fma}\left(a - 0.5, \log t, \log z\right) + \log y\right) - t \end{array} \]
                              (FPCore (x y z t a)
                               :precision binary64
                               (- (+ (fma (- a 0.5) (log t) (log z)) (log y)) t))
                              double code(double x, double y, double z, double t, double a) {
                              	return (fma((a - 0.5), log(t), log(z)) + log(y)) - t;
                              }
                              
                              function code(x, y, z, t, a)
                              	return Float64(Float64(fma(Float64(a - 0.5), log(t), log(z)) + log(y)) - t)
                              end
                              
                              code[x_, y_, z_, t_, a_] := N[(N[(N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]
                              
                              \begin{array}{l}
                              
                              \\
                              \left(\mathsf{fma}\left(a - 0.5, \log t, \log z\right) + \log y\right) - t
                              \end{array}
                              
                              Derivation
                              1. Initial program 99.7%

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

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

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

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

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

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

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

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

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

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

                                  \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                              5. Applied rewrites72.0%

                                \[\leadsto \color{blue}{\left(\log y + \mathsf{fma}\left(a - 0.5, \log t, \log z\right)\right) - t} \]
                              6. Final simplification72.0%

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

                              Alternative 13: 57.3% accurate, 1.5× speedup?

                              \[\begin{array}{l} \\ \left(\log t \cdot a + \log y\right) - t \end{array} \]
                              (FPCore (x y z t a) :precision binary64 (- (+ (* (log t) a) (log y)) t))
                              double code(double x, double y, double z, double t, double a) {
                              	return ((log(t) * a) + log(y)) - t;
                              }
                              
                              real(8) function code(x, y, z, t, a)
                                  real(8), intent (in) :: x
                                  real(8), intent (in) :: y
                                  real(8), intent (in) :: z
                                  real(8), intent (in) :: t
                                  real(8), intent (in) :: a
                                  code = ((log(t) * a) + log(y)) - t
                              end function
                              
                              public static double code(double x, double y, double z, double t, double a) {
                              	return ((Math.log(t) * a) + Math.log(y)) - t;
                              }
                              
                              def code(x, y, z, t, a):
                              	return ((math.log(t) * a) + math.log(y)) - t
                              
                              function code(x, y, z, t, a)
                              	return Float64(Float64(Float64(log(t) * a) + log(y)) - t)
                              end
                              
                              function tmp = code(x, y, z, t, a)
                              	tmp = ((log(t) * a) + log(y)) - t;
                              end
                              
                              code[x_, y_, z_, t_, a_] := N[(N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]
                              
                              \begin{array}{l}
                              
                              \\
                              \left(\log t \cdot a + \log y\right) - t
                              \end{array}
                              
                              Derivation
                              1. Initial program 99.7%

                                \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
                              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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

                                  \[\leadsto \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - \left(t - \left(a - \frac{1}{2}\right) \cdot \log t\right) \]
                                15. lower--.f6479.4

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

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

                                  \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - \frac{1}{2}\right)}\right) \]
                                18. lower-*.f6479.4

                                  \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
                              4. Applied rewrites79.4%

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

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

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

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

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

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

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

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

                                  \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                              7. Applied rewrites72.0%

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

                                \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
                              9. Step-by-step derivation
                                1. Applied rewrites61.8%

                                  \[\leadsto \left(\log y + a \cdot \log t\right) - t \]
                                2. Final simplification61.8%

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

                                Alternative 14: 61.9% accurate, 2.6× speedup?

                                \[\begin{array}{l} \\ \begin{array}{l} t_1 := \log t \cdot a\\ \mathbf{if}\;a - 0.5 \leq -1 \cdot 10^{+70}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;a - 0.5 \leq 4000000000:\\ \;\;\;\;-t\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
                                (FPCore (x y z t a)
                                 :precision binary64
                                 (let* ((t_1 (* (log t) a)))
                                   (if (<= (- a 0.5) -1e+70) t_1 (if (<= (- a 0.5) 4000000000.0) (- t) t_1))))
                                double code(double x, double y, double z, double t, double a) {
                                	double t_1 = log(t) * a;
                                	double tmp;
                                	if ((a - 0.5) <= -1e+70) {
                                		tmp = t_1;
                                	} else if ((a - 0.5) <= 4000000000.0) {
                                		tmp = -t;
                                	} else {
                                		tmp = t_1;
                                	}
                                	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) :: tmp
                                    t_1 = log(t) * a
                                    if ((a - 0.5d0) <= (-1d+70)) then
                                        tmp = t_1
                                    else if ((a - 0.5d0) <= 4000000000.0d0) then
                                        tmp = -t
                                    else
                                        tmp = t_1
                                    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(t) * a;
                                	double tmp;
                                	if ((a - 0.5) <= -1e+70) {
                                		tmp = t_1;
                                	} else if ((a - 0.5) <= 4000000000.0) {
                                		tmp = -t;
                                	} else {
                                		tmp = t_1;
                                	}
                                	return tmp;
                                }
                                
                                def code(x, y, z, t, a):
                                	t_1 = math.log(t) * a
                                	tmp = 0
                                	if (a - 0.5) <= -1e+70:
                                		tmp = t_1
                                	elif (a - 0.5) <= 4000000000.0:
                                		tmp = -t
                                	else:
                                		tmp = t_1
                                	return tmp
                                
                                function code(x, y, z, t, a)
                                	t_1 = Float64(log(t) * a)
                                	tmp = 0.0
                                	if (Float64(a - 0.5) <= -1e+70)
                                		tmp = t_1;
                                	elseif (Float64(a - 0.5) <= 4000000000.0)
                                		tmp = Float64(-t);
                                	else
                                		tmp = t_1;
                                	end
                                	return tmp
                                end
                                
                                function tmp_2 = code(x, y, z, t, a)
                                	t_1 = log(t) * a;
                                	tmp = 0.0;
                                	if ((a - 0.5) <= -1e+70)
                                		tmp = t_1;
                                	elseif ((a - 0.5) <= 4000000000.0)
                                		tmp = -t;
                                	else
                                		tmp = t_1;
                                	end
                                	tmp_2 = tmp;
                                end
                                
                                code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision]}, If[LessEqual[N[(a - 0.5), $MachinePrecision], -1e+70], t$95$1, If[LessEqual[N[(a - 0.5), $MachinePrecision], 4000000000.0], (-t), t$95$1]]]
                                
                                \begin{array}{l}
                                
                                \\
                                \begin{array}{l}
                                t_1 := \log t \cdot a\\
                                \mathbf{if}\;a - 0.5 \leq -1 \cdot 10^{+70}:\\
                                \;\;\;\;t\_1\\
                                
                                \mathbf{elif}\;a - 0.5 \leq 4000000000:\\
                                \;\;\;\;-t\\
                                
                                \mathbf{else}:\\
                                \;\;\;\;t\_1\\
                                
                                
                                \end{array}
                                \end{array}
                                
                                Derivation
                                1. Split input into 2 regimes
                                2. if (-.f64 a #s(literal 1/2 binary64)) < -1.00000000000000007e70 or 4e9 < (-.f64 a #s(literal 1/2 binary64))

                                  1. Initial program 99.8%

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

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

                                      \[\leadsto \color{blue}{a \cdot \log t} \]
                                    2. lower-log.f6482.5

                                      \[\leadsto a \cdot \color{blue}{\log t} \]
                                  5. Applied rewrites82.5%

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

                                  if -1.00000000000000007e70 < (-.f64 a #s(literal 1/2 binary64)) < 4e9

                                  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 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.f6457.2

                                      \[\leadsto \color{blue}{-t} \]
                                  5. Applied rewrites57.2%

                                    \[\leadsto \color{blue}{-t} \]
                                3. Recombined 2 regimes into one program.
                                4. Final simplification69.8%

                                  \[\leadsto \begin{array}{l} \mathbf{if}\;a - 0.5 \leq -1 \cdot 10^{+70}:\\ \;\;\;\;\log t \cdot a\\ \mathbf{elif}\;a - 0.5 \leq 4000000000:\\ \;\;\;\;-t\\ \mathbf{else}:\\ \;\;\;\;\log t \cdot a\\ \end{array} \]
                                5. Add Preprocessing

                                Alternative 15: 76.9% accurate, 2.8× speedup?

                                \[\begin{array}{l} \\ \left(-t\right) - \left(0.5 - a\right) \cdot \log t \end{array} \]
                                (FPCore (x y z t a) :precision binary64 (- (- t) (* (- 0.5 a) (log t))))
                                double code(double x, double y, double z, double t, double a) {
                                	return -t - ((0.5 - a) * 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 = -t - ((0.5d0 - a) * log(t))
                                end function
                                
                                public static double code(double x, double y, double z, double t, double a) {
                                	return -t - ((0.5 - a) * Math.log(t));
                                }
                                
                                def code(x, y, z, t, a):
                                	return -t - ((0.5 - a) * math.log(t))
                                
                                function code(x, y, z, t, a)
                                	return Float64(Float64(-t) - Float64(Float64(0.5 - a) * log(t)))
                                end
                                
                                function tmp = code(x, y, z, t, a)
                                	tmp = -t - ((0.5 - a) * log(t));
                                end
                                
                                code[x_, y_, z_, t_, a_] := N[((-t) - N[(N[(0.5 - a), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
                                
                                \begin{array}{l}
                                
                                \\
                                \left(-t\right) - \left(0.5 - a\right) \cdot \log t
                                \end{array}
                                
                                Derivation
                                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 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.f6481.6

                                    \[\leadsto \color{blue}{\left(-t\right)} + \left(a - 0.5\right) \cdot \log t \]
                                5. Applied rewrites81.6%

                                  \[\leadsto \color{blue}{\left(-t\right)} + \left(a - 0.5\right) \cdot \log t \]
                                6. Final simplification81.6%

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

                                Alternative 16: 74.3% accurate, 2.9× speedup?

                                \[\begin{array}{l} \\ \log t \cdot a - t \end{array} \]
                                (FPCore (x y z t a) :precision binary64 (- (* (log t) a) t))
                                double code(double x, double y, double z, double t, double a) {
                                	return (log(t) * a) - t;
                                }
                                
                                real(8) function code(x, y, z, t, a)
                                    real(8), intent (in) :: x
                                    real(8), intent (in) :: y
                                    real(8), intent (in) :: z
                                    real(8), intent (in) :: t
                                    real(8), intent (in) :: a
                                    code = (log(t) * a) - t
                                end function
                                
                                public static double code(double x, double y, double z, double t, double a) {
                                	return (Math.log(t) * a) - t;
                                }
                                
                                def code(x, y, z, t, a):
                                	return (math.log(t) * a) - t
                                
                                function code(x, y, z, t, a)
                                	return Float64(Float64(log(t) * a) - t)
                                end
                                
                                function tmp = code(x, y, z, t, a)
                                	tmp = (log(t) * a) - t;
                                end
                                
                                code[x_, y_, z_, t_, a_] := N[(N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision] - t), $MachinePrecision]
                                
                                \begin{array}{l}
                                
                                \\
                                \log t \cdot a - t
                                \end{array}
                                
                                Derivation
                                1. Initial program 99.7%

                                  \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
                                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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

                                    \[\leadsto \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - \left(t - \left(a - \frac{1}{2}\right) \cdot \log t\right) \]
                                  15. lower--.f6479.4

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

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

                                    \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - \frac{1}{2}\right)}\right) \]
                                  18. lower-*.f6479.4

                                    \[\leadsto \log \left(z \cdot \left(y + x\right)\right) - \left(t - \color{blue}{\log t \cdot \left(a - 0.5\right)}\right) \]
                                4. Applied rewrites79.4%

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

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

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

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

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

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

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

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

                                    \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                                7. Applied rewrites72.0%

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

                                  \[\leadsto a \cdot \log t - t \]
                                9. Step-by-step derivation
                                  1. Applied rewrites79.5%

                                    \[\leadsto a \cdot \log t - t \]
                                  2. Final simplification79.5%

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

                                  Alternative 17: 38.2% 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 99.7%

                                    \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
                                  2. Add Preprocessing
                                  3. Taylor expanded in 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.f6437.9

                                      \[\leadsto \color{blue}{-t} \]
                                  5. Applied rewrites37.9%

                                    \[\leadsto \color{blue}{-t} \]
                                  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 2024278 
                                  (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))))