Numeric.AD.Rank1.Halley:findZero from ad-4.2.4

Percentage Accurate: 82.1% → 98.2%
Time: 8.5s
Alternatives: 6
Speedup: 1.5×

Specification

?
\[\begin{array}{l} \\ x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (- x (/ (* (* y 2.0) z) (- (* (* z 2.0) z) (* y t)))))
double code(double x, double y, double z, double t) {
	return x - (((y * 2.0) * z) / (((z * 2.0) * z) - (y * t)));
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    code = x - (((y * 2.0d0) * z) / (((z * 2.0d0) * z) - (y * t)))
end function
public static double code(double x, double y, double z, double t) {
	return x - (((y * 2.0) * z) / (((z * 2.0) * z) - (y * t)));
}
def code(x, y, z, t):
	return x - (((y * 2.0) * z) / (((z * 2.0) * z) - (y * t)))
function code(x, y, z, t)
	return Float64(x - Float64(Float64(Float64(y * 2.0) * z) / Float64(Float64(Float64(z * 2.0) * z) - Float64(y * t))))
end
function tmp = code(x, y, z, t)
	tmp = x - (((y * 2.0) * z) / (((z * 2.0) * z) - (y * t)));
end
code[x_, y_, z_, t_] := N[(x - N[(N[(N[(y * 2.0), $MachinePrecision] * z), $MachinePrecision] / N[(N[(N[(z * 2.0), $MachinePrecision] * z), $MachinePrecision] - N[(y * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot 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 6 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: 82.1% accurate, 1.0× speedup?

\[\begin{array}{l} \\ x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (- x (/ (* (* y 2.0) z) (- (* (* z 2.0) z) (* y t)))))
double code(double x, double y, double z, double t) {
	return x - (((y * 2.0) * z) / (((z * 2.0) * z) - (y * t)));
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    code = x - (((y * 2.0d0) * z) / (((z * 2.0d0) * z) - (y * t)))
end function
public static double code(double x, double y, double z, double t) {
	return x - (((y * 2.0) * z) / (((z * 2.0) * z) - (y * t)));
}
def code(x, y, z, t):
	return x - (((y * 2.0) * z) / (((z * 2.0) * z) - (y * t)))
function code(x, y, z, t)
	return Float64(x - Float64(Float64(Float64(y * 2.0) * z) / Float64(Float64(Float64(z * 2.0) * z) - Float64(y * t))))
end
function tmp = code(x, y, z, t)
	tmp = x - (((y * 2.0) * z) / (((z * 2.0) * z) - (y * t)));
end
code[x_, y_, z_, t_] := N[(x - N[(N[(N[(y * 2.0), $MachinePrecision] * z), $MachinePrecision] / N[(N[(N[(z * 2.0), $MachinePrecision] * z), $MachinePrecision] - N[(y * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}
\end{array}

Alternative 1: 98.2% accurate, 1.0× speedup?

\[\begin{array}{l} \\ x + \frac{-1}{0.5 \cdot \frac{z \cdot 2 - y \cdot \frac{t}{z}}{y}} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (+ x (/ -1.0 (* 0.5 (/ (- (* z 2.0) (* y (/ t z))) y)))))
double code(double x, double y, double z, double t) {
	return x + (-1.0 / (0.5 * (((z * 2.0) - (y * (t / z))) / y)));
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    code = x + ((-1.0d0) / (0.5d0 * (((z * 2.0d0) - (y * (t / z))) / y)))
end function
public static double code(double x, double y, double z, double t) {
	return x + (-1.0 / (0.5 * (((z * 2.0) - (y * (t / z))) / y)));
}
def code(x, y, z, t):
	return x + (-1.0 / (0.5 * (((z * 2.0) - (y * (t / z))) / y)))
function code(x, y, z, t)
	return Float64(x + Float64(-1.0 / Float64(0.5 * Float64(Float64(Float64(z * 2.0) - Float64(y * Float64(t / z))) / y))))
end
function tmp = code(x, y, z, t)
	tmp = x + (-1.0 / (0.5 * (((z * 2.0) - (y * (t / z))) / y)));
end
code[x_, y_, z_, t_] := N[(x + N[(-1.0 / N[(0.5 * N[(N[(N[(z * 2.0), $MachinePrecision] - N[(y * N[(t / z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x + \frac{-1}{0.5 \cdot \frac{z \cdot 2 - y \cdot \frac{t}{z}}{y}}
\end{array}
Derivation
  1. Initial program 79.4%

    \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
  2. Step-by-step derivation
    1. remove-double-neg79.4%

      \[\leadsto x - \color{blue}{\left(-\left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)\right)} \]
    2. neg-mul-179.4%

      \[\leadsto x - \color{blue}{-1 \cdot \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
    3. *-commutative79.4%

      \[\leadsto x - \color{blue}{\left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right) \cdot -1} \]
    4. *-commutative79.4%

      \[\leadsto x - \color{blue}{-1 \cdot \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
    5. neg-mul-179.4%

      \[\leadsto x - \color{blue}{\left(-\left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)\right)} \]
    6. remove-double-neg79.4%

      \[\leadsto x - \color{blue}{\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}} \]
    7. associate-/l*87.6%

      \[\leadsto x - \color{blue}{\frac{y \cdot 2}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}}} \]
    8. associate-*l*87.6%

      \[\leadsto x - \frac{y \cdot 2}{\frac{\color{blue}{z \cdot \left(2 \cdot z\right)} - y \cdot t}{z}} \]
  3. Simplified87.6%

    \[\leadsto \color{blue}{x - \frac{y \cdot 2}{\frac{z \cdot \left(2 \cdot z\right) - y \cdot t}{z}}} \]
  4. Taylor expanded in z around 0 94.4%

    \[\leadsto x - \frac{y \cdot 2}{\color{blue}{-1 \cdot \frac{t \cdot y}{z} + 2 \cdot z}} \]
  5. Step-by-step derivation
    1. +-commutative94.4%

      \[\leadsto x - \frac{y \cdot 2}{\color{blue}{2 \cdot z + -1 \cdot \frac{t \cdot y}{z}}} \]
    2. mul-1-neg94.4%

      \[\leadsto x - \frac{y \cdot 2}{2 \cdot z + \color{blue}{\left(-\frac{t \cdot y}{z}\right)}} \]
    3. associate-*r/97.0%

      \[\leadsto x - \frac{y \cdot 2}{2 \cdot z + \left(-\color{blue}{t \cdot \frac{y}{z}}\right)} \]
    4. *-commutative97.0%

      \[\leadsto x - \frac{y \cdot 2}{2 \cdot z + \left(-\color{blue}{\frac{y}{z} \cdot t}\right)} \]
    5. associate-/r/98.6%

      \[\leadsto x - \frac{y \cdot 2}{2 \cdot z + \left(-\color{blue}{\frac{y}{\frac{z}{t}}}\right)} \]
    6. unsub-neg98.6%

      \[\leadsto x - \frac{y \cdot 2}{\color{blue}{2 \cdot z - \frac{y}{\frac{z}{t}}}} \]
    7. *-commutative98.6%

      \[\leadsto x - \frac{y \cdot 2}{\color{blue}{z \cdot 2} - \frac{y}{\frac{z}{t}}} \]
    8. associate-/r/97.0%

      \[\leadsto x - \frac{y \cdot 2}{z \cdot 2 - \color{blue}{\frac{y}{z} \cdot t}} \]
    9. *-commutative97.0%

      \[\leadsto x - \frac{y \cdot 2}{z \cdot 2 - \color{blue}{t \cdot \frac{y}{z}}} \]
  6. Simplified97.0%

    \[\leadsto x - \frac{y \cdot 2}{\color{blue}{z \cdot 2 - t \cdot \frac{y}{z}}} \]
  7. Step-by-step derivation
    1. clear-num96.7%

      \[\leadsto x - \color{blue}{\frac{1}{\frac{z \cdot 2 - t \cdot \frac{y}{z}}{y \cdot 2}}} \]
    2. inv-pow96.7%

      \[\leadsto x - \color{blue}{{\left(\frac{z \cdot 2 - t \cdot \frac{y}{z}}{y \cdot 2}\right)}^{-1}} \]
    3. *-un-lft-identity96.7%

      \[\leadsto x - {\left(\frac{\color{blue}{1 \cdot \left(z \cdot 2 - t \cdot \frac{y}{z}\right)}}{y \cdot 2}\right)}^{-1} \]
    4. *-commutative96.7%

      \[\leadsto x - {\left(\frac{1 \cdot \left(z \cdot 2 - t \cdot \frac{y}{z}\right)}{\color{blue}{2 \cdot y}}\right)}^{-1} \]
    5. times-frac96.7%

      \[\leadsto x - {\color{blue}{\left(\frac{1}{2} \cdot \frac{z \cdot 2 - t \cdot \frac{y}{z}}{y}\right)}}^{-1} \]
    6. metadata-eval96.7%

      \[\leadsto x - {\left(\color{blue}{0.5} \cdot \frac{z \cdot 2 - t \cdot \frac{y}{z}}{y}\right)}^{-1} \]
    7. *-commutative96.7%

      \[\leadsto x - {\left(0.5 \cdot \frac{\color{blue}{2 \cdot z} - t \cdot \frac{y}{z}}{y}\right)}^{-1} \]
  8. Applied egg-rr96.7%

    \[\leadsto x - \color{blue}{{\left(0.5 \cdot \frac{2 \cdot z - t \cdot \frac{y}{z}}{y}\right)}^{-1}} \]
  9. Step-by-step derivation
    1. unpow-196.7%

      \[\leadsto x - \color{blue}{\frac{1}{0.5 \cdot \frac{2 \cdot z - t \cdot \frac{y}{z}}{y}}} \]
    2. *-commutative96.7%

      \[\leadsto x - \frac{1}{0.5 \cdot \frac{2 \cdot z - \color{blue}{\frac{y}{z} \cdot t}}{y}} \]
    3. associate-*l/94.1%

      \[\leadsto x - \frac{1}{0.5 \cdot \frac{2 \cdot z - \color{blue}{\frac{y \cdot t}{z}}}{y}} \]
    4. associate-*r/98.3%

      \[\leadsto x - \frac{1}{0.5 \cdot \frac{2 \cdot z - \color{blue}{y \cdot \frac{t}{z}}}{y}} \]
    5. *-commutative98.3%

      \[\leadsto x - \frac{1}{0.5 \cdot \frac{\color{blue}{z \cdot 2} - y \cdot \frac{t}{z}}{y}} \]
  10. Simplified98.3%

    \[\leadsto x - \color{blue}{\frac{1}{0.5 \cdot \frac{z \cdot 2 - y \cdot \frac{t}{z}}{y}}} \]
  11. Final simplification98.3%

    \[\leadsto x + \frac{-1}{0.5 \cdot \frac{z \cdot 2 - y \cdot \frac{t}{z}}{y}} \]

Alternative 2: 96.1% accurate, 1.1× speedup?

\[\begin{array}{l} \\ x - \frac{2 \cdot y}{z \cdot 2 - t \cdot \frac{y}{z}} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (- x (/ (* 2.0 y) (- (* z 2.0) (* t (/ y z))))))
double code(double x, double y, double z, double t) {
	return x - ((2.0 * y) / ((z * 2.0) - (t * (y / z))));
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    code = x - ((2.0d0 * y) / ((z * 2.0d0) - (t * (y / z))))
end function
public static double code(double x, double y, double z, double t) {
	return x - ((2.0 * y) / ((z * 2.0) - (t * (y / z))));
}
def code(x, y, z, t):
	return x - ((2.0 * y) / ((z * 2.0) - (t * (y / z))))
function code(x, y, z, t)
	return Float64(x - Float64(Float64(2.0 * y) / Float64(Float64(z * 2.0) - Float64(t * Float64(y / z)))))
end
function tmp = code(x, y, z, t)
	tmp = x - ((2.0 * y) / ((z * 2.0) - (t * (y / z))));
end
code[x_, y_, z_, t_] := N[(x - N[(N[(2.0 * y), $MachinePrecision] / N[(N[(z * 2.0), $MachinePrecision] - N[(t * N[(y / z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x - \frac{2 \cdot y}{z \cdot 2 - t \cdot \frac{y}{z}}
\end{array}
Derivation
  1. Initial program 79.4%

    \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
  2. Step-by-step derivation
    1. remove-double-neg79.4%

      \[\leadsto x - \color{blue}{\left(-\left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)\right)} \]
    2. neg-mul-179.4%

      \[\leadsto x - \color{blue}{-1 \cdot \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
    3. *-commutative79.4%

      \[\leadsto x - \color{blue}{\left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right) \cdot -1} \]
    4. *-commutative79.4%

      \[\leadsto x - \color{blue}{-1 \cdot \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
    5. neg-mul-179.4%

      \[\leadsto x - \color{blue}{\left(-\left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)\right)} \]
    6. remove-double-neg79.4%

      \[\leadsto x - \color{blue}{\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}} \]
    7. associate-/l*87.6%

      \[\leadsto x - \color{blue}{\frac{y \cdot 2}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}}} \]
    8. associate-*l*87.6%

      \[\leadsto x - \frac{y \cdot 2}{\frac{\color{blue}{z \cdot \left(2 \cdot z\right)} - y \cdot t}{z}} \]
  3. Simplified87.6%

    \[\leadsto \color{blue}{x - \frac{y \cdot 2}{\frac{z \cdot \left(2 \cdot z\right) - y \cdot t}{z}}} \]
  4. Taylor expanded in z around 0 94.4%

    \[\leadsto x - \frac{y \cdot 2}{\color{blue}{-1 \cdot \frac{t \cdot y}{z} + 2 \cdot z}} \]
  5. Step-by-step derivation
    1. +-commutative94.4%

      \[\leadsto x - \frac{y \cdot 2}{\color{blue}{2 \cdot z + -1 \cdot \frac{t \cdot y}{z}}} \]
    2. mul-1-neg94.4%

      \[\leadsto x - \frac{y \cdot 2}{2 \cdot z + \color{blue}{\left(-\frac{t \cdot y}{z}\right)}} \]
    3. associate-*r/97.0%

      \[\leadsto x - \frac{y \cdot 2}{2 \cdot z + \left(-\color{blue}{t \cdot \frac{y}{z}}\right)} \]
    4. *-commutative97.0%

      \[\leadsto x - \frac{y \cdot 2}{2 \cdot z + \left(-\color{blue}{\frac{y}{z} \cdot t}\right)} \]
    5. associate-/r/98.6%

      \[\leadsto x - \frac{y \cdot 2}{2 \cdot z + \left(-\color{blue}{\frac{y}{\frac{z}{t}}}\right)} \]
    6. unsub-neg98.6%

      \[\leadsto x - \frac{y \cdot 2}{\color{blue}{2 \cdot z - \frac{y}{\frac{z}{t}}}} \]
    7. *-commutative98.6%

      \[\leadsto x - \frac{y \cdot 2}{\color{blue}{z \cdot 2} - \frac{y}{\frac{z}{t}}} \]
    8. associate-/r/97.0%

      \[\leadsto x - \frac{y \cdot 2}{z \cdot 2 - \color{blue}{\frac{y}{z} \cdot t}} \]
    9. *-commutative97.0%

      \[\leadsto x - \frac{y \cdot 2}{z \cdot 2 - \color{blue}{t \cdot \frac{y}{z}}} \]
  6. Simplified97.0%

    \[\leadsto x - \frac{y \cdot 2}{\color{blue}{z \cdot 2 - t \cdot \frac{y}{z}}} \]
  7. Final simplification97.0%

    \[\leadsto x - \frac{2 \cdot y}{z \cdot 2 - t \cdot \frac{y}{z}} \]

Alternative 3: 88.6% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -2.2 \cdot 10^{+35} \lor \neg \left(z \leq 2.55 \cdot 10^{-36}\right):\\ \;\;\;\;x - \frac{y}{z}\\ \mathbf{else}:\\ \;\;\;\;x + z \cdot \frac{2}{t}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (or (<= z -2.2e+35) (not (<= z 2.55e-36)))
   (- x (/ y z))
   (+ x (* z (/ 2.0 t)))))
double code(double x, double y, double z, double t) {
	double tmp;
	if ((z <= -2.2e+35) || !(z <= 2.55e-36)) {
		tmp = x - (y / z);
	} else {
		tmp = x + (z * (2.0 / t));
	}
	return tmp;
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: tmp
    if ((z <= (-2.2d+35)) .or. (.not. (z <= 2.55d-36))) then
        tmp = x - (y / z)
    else
        tmp = x + (z * (2.0d0 / t))
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double tmp;
	if ((z <= -2.2e+35) || !(z <= 2.55e-36)) {
		tmp = x - (y / z);
	} else {
		tmp = x + (z * (2.0 / t));
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if (z <= -2.2e+35) or not (z <= 2.55e-36):
		tmp = x - (y / z)
	else:
		tmp = x + (z * (2.0 / t))
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if ((z <= -2.2e+35) || !(z <= 2.55e-36))
		tmp = Float64(x - Float64(y / z));
	else
		tmp = Float64(x + Float64(z * Float64(2.0 / t)));
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	tmp = 0.0;
	if ((z <= -2.2e+35) || ~((z <= 2.55e-36)))
		tmp = x - (y / z);
	else
		tmp = x + (z * (2.0 / t));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := If[Or[LessEqual[z, -2.2e+35], N[Not[LessEqual[z, 2.55e-36]], $MachinePrecision]], N[(x - N[(y / z), $MachinePrecision]), $MachinePrecision], N[(x + N[(z * N[(2.0 / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq -2.2 \cdot 10^{+35} \lor \neg \left(z \leq 2.55 \cdot 10^{-36}\right):\\
\;\;\;\;x - \frac{y}{z}\\

\mathbf{else}:\\
\;\;\;\;x + z \cdot \frac{2}{t}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -2.1999999999999999e35 or 2.54999999999999987e-36 < z

    1. Initial program 69.8%

      \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
    2. Step-by-step derivation
      1. sub-neg69.8%

        \[\leadsto \color{blue}{x + \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
      2. associate-/l*84.5%

        \[\leadsto x + \left(-\color{blue}{\frac{y \cdot 2}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}}}\right) \]
      3. distribute-neg-frac84.5%

        \[\leadsto x + \color{blue}{\frac{-y \cdot 2}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}}} \]
      4. distribute-lft-neg-out84.5%

        \[\leadsto x + \frac{\color{blue}{\left(-y\right) \cdot 2}}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}} \]
      5. associate-/r/82.6%

        \[\leadsto x + \color{blue}{\frac{\left(-y\right) \cdot 2}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z} \]
      6. distribute-lft-neg-out82.6%

        \[\leadsto x + \frac{\color{blue}{-y \cdot 2}}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z \]
      7. distribute-rgt-neg-in82.6%

        \[\leadsto x + \frac{\color{blue}{y \cdot \left(-2\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z \]
      8. metadata-eval82.6%

        \[\leadsto x + \frac{y \cdot \color{blue}{-2}}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z \]
      9. *-commutative82.6%

        \[\leadsto x + \frac{y \cdot -2}{\color{blue}{\left(2 \cdot z\right)} \cdot z - y \cdot t} \cdot z \]
      10. associate-*l*82.6%

        \[\leadsto x + \frac{y \cdot -2}{\color{blue}{2 \cdot \left(z \cdot z\right)} - y \cdot t} \cdot z \]
      11. fma-neg82.6%

        \[\leadsto x + \frac{y \cdot -2}{\color{blue}{\mathsf{fma}\left(2, z \cdot z, -y \cdot t\right)}} \cdot z \]
    3. Simplified82.6%

      \[\leadsto \color{blue}{x + \frac{y \cdot -2}{\mathsf{fma}\left(2, z \cdot z, -y \cdot t\right)} \cdot z} \]
    4. Taylor expanded in y around 0 92.4%

      \[\leadsto \color{blue}{x + -1 \cdot \frac{y}{z}} \]
    5. Step-by-step derivation
      1. mul-1-neg92.4%

        \[\leadsto x + \color{blue}{\left(-\frac{y}{z}\right)} \]
      2. sub-neg92.4%

        \[\leadsto \color{blue}{x - \frac{y}{z}} \]
    6. Simplified92.4%

      \[\leadsto \color{blue}{x - \frac{y}{z}} \]

    if -2.1999999999999999e35 < z < 2.54999999999999987e-36

    1. Initial program 88.4%

      \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
    2. Step-by-step derivation
      1. sub-neg88.4%

        \[\leadsto \color{blue}{x + \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
      2. associate-/l*90.4%

        \[\leadsto x + \left(-\color{blue}{\frac{y \cdot 2}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}}}\right) \]
      3. distribute-neg-frac90.4%

        \[\leadsto x + \color{blue}{\frac{-y \cdot 2}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}}} \]
      4. distribute-lft-neg-out90.4%

        \[\leadsto x + \frac{\color{blue}{\left(-y\right) \cdot 2}}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}} \]
      5. associate-/r/91.6%

        \[\leadsto x + \color{blue}{\frac{\left(-y\right) \cdot 2}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z} \]
      6. distribute-lft-neg-out91.6%

        \[\leadsto x + \frac{\color{blue}{-y \cdot 2}}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z \]
      7. distribute-rgt-neg-in91.6%

        \[\leadsto x + \frac{\color{blue}{y \cdot \left(-2\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z \]
      8. metadata-eval91.6%

        \[\leadsto x + \frac{y \cdot \color{blue}{-2}}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z \]
      9. *-commutative91.6%

        \[\leadsto x + \frac{y \cdot -2}{\color{blue}{\left(2 \cdot z\right)} \cdot z - y \cdot t} \cdot z \]
      10. associate-*l*91.6%

        \[\leadsto x + \frac{y \cdot -2}{\color{blue}{2 \cdot \left(z \cdot z\right)} - y \cdot t} \cdot z \]
      11. fma-neg91.6%

        \[\leadsto x + \frac{y \cdot -2}{\color{blue}{\mathsf{fma}\left(2, z \cdot z, -y \cdot t\right)}} \cdot z \]
    3. Simplified91.6%

      \[\leadsto \color{blue}{x + \frac{y \cdot -2}{\mathsf{fma}\left(2, z \cdot z, -y \cdot t\right)} \cdot z} \]
    4. Taylor expanded in y around inf 90.3%

      \[\leadsto x + \color{blue}{\frac{2}{t}} \cdot z \]
  3. Recombined 2 regimes into one program.
  4. Final simplification91.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -2.2 \cdot 10^{+35} \lor \neg \left(z \leq 2.55 \cdot 10^{-36}\right):\\ \;\;\;\;x - \frac{y}{z}\\ \mathbf{else}:\\ \;\;\;\;x + z \cdot \frac{2}{t}\\ \end{array} \]

Alternative 4: 88.6% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -3.3 \cdot 10^{+37} \lor \neg \left(z \leq 2.55 \cdot 10^{-36}\right):\\ \;\;\;\;x - \frac{y}{z}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{z}{t} \cdot -2\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (or (<= z -3.3e+37) (not (<= z 2.55e-36)))
   (- x (/ y z))
   (- x (* (/ z t) -2.0))))
double code(double x, double y, double z, double t) {
	double tmp;
	if ((z <= -3.3e+37) || !(z <= 2.55e-36)) {
		tmp = x - (y / z);
	} else {
		tmp = x - ((z / t) * -2.0);
	}
	return tmp;
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: tmp
    if ((z <= (-3.3d+37)) .or. (.not. (z <= 2.55d-36))) then
        tmp = x - (y / z)
    else
        tmp = x - ((z / t) * (-2.0d0))
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double tmp;
	if ((z <= -3.3e+37) || !(z <= 2.55e-36)) {
		tmp = x - (y / z);
	} else {
		tmp = x - ((z / t) * -2.0);
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if (z <= -3.3e+37) or not (z <= 2.55e-36):
		tmp = x - (y / z)
	else:
		tmp = x - ((z / t) * -2.0)
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if ((z <= -3.3e+37) || !(z <= 2.55e-36))
		tmp = Float64(x - Float64(y / z));
	else
		tmp = Float64(x - Float64(Float64(z / t) * -2.0));
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	tmp = 0.0;
	if ((z <= -3.3e+37) || ~((z <= 2.55e-36)))
		tmp = x - (y / z);
	else
		tmp = x - ((z / t) * -2.0);
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := If[Or[LessEqual[z, -3.3e+37], N[Not[LessEqual[z, 2.55e-36]], $MachinePrecision]], N[(x - N[(y / z), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[(z / t), $MachinePrecision] * -2.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq -3.3 \cdot 10^{+37} \lor \neg \left(z \leq 2.55 \cdot 10^{-36}\right):\\
\;\;\;\;x - \frac{y}{z}\\

\mathbf{else}:\\
\;\;\;\;x - \frac{z}{t} \cdot -2\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -3.3000000000000001e37 or 2.54999999999999987e-36 < z

    1. Initial program 69.8%

      \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
    2. Step-by-step derivation
      1. sub-neg69.8%

        \[\leadsto \color{blue}{x + \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
      2. associate-/l*84.5%

        \[\leadsto x + \left(-\color{blue}{\frac{y \cdot 2}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}}}\right) \]
      3. distribute-neg-frac84.5%

        \[\leadsto x + \color{blue}{\frac{-y \cdot 2}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}}} \]
      4. distribute-lft-neg-out84.5%

        \[\leadsto x + \frac{\color{blue}{\left(-y\right) \cdot 2}}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}} \]
      5. associate-/r/82.6%

        \[\leadsto x + \color{blue}{\frac{\left(-y\right) \cdot 2}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z} \]
      6. distribute-lft-neg-out82.6%

        \[\leadsto x + \frac{\color{blue}{-y \cdot 2}}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z \]
      7. distribute-rgt-neg-in82.6%

        \[\leadsto x + \frac{\color{blue}{y \cdot \left(-2\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z \]
      8. metadata-eval82.6%

        \[\leadsto x + \frac{y \cdot \color{blue}{-2}}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z \]
      9. *-commutative82.6%

        \[\leadsto x + \frac{y \cdot -2}{\color{blue}{\left(2 \cdot z\right)} \cdot z - y \cdot t} \cdot z \]
      10. associate-*l*82.6%

        \[\leadsto x + \frac{y \cdot -2}{\color{blue}{2 \cdot \left(z \cdot z\right)} - y \cdot t} \cdot z \]
      11. fma-neg82.6%

        \[\leadsto x + \frac{y \cdot -2}{\color{blue}{\mathsf{fma}\left(2, z \cdot z, -y \cdot t\right)}} \cdot z \]
    3. Simplified82.6%

      \[\leadsto \color{blue}{x + \frac{y \cdot -2}{\mathsf{fma}\left(2, z \cdot z, -y \cdot t\right)} \cdot z} \]
    4. Taylor expanded in y around 0 92.4%

      \[\leadsto \color{blue}{x + -1 \cdot \frac{y}{z}} \]
    5. Step-by-step derivation
      1. mul-1-neg92.4%

        \[\leadsto x + \color{blue}{\left(-\frac{y}{z}\right)} \]
      2. sub-neg92.4%

        \[\leadsto \color{blue}{x - \frac{y}{z}} \]
    6. Simplified92.4%

      \[\leadsto \color{blue}{x - \frac{y}{z}} \]

    if -3.3000000000000001e37 < z < 2.54999999999999987e-36

    1. Initial program 88.4%

      \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
    2. Step-by-step derivation
      1. remove-double-neg88.4%

        \[\leadsto x - \color{blue}{\left(-\left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)\right)} \]
      2. neg-mul-188.4%

        \[\leadsto x - \color{blue}{-1 \cdot \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
      3. *-commutative88.4%

        \[\leadsto x - \color{blue}{\left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right) \cdot -1} \]
      4. *-commutative88.4%

        \[\leadsto x - \color{blue}{-1 \cdot \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
      5. neg-mul-188.4%

        \[\leadsto x - \color{blue}{\left(-\left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)\right)} \]
      6. remove-double-neg88.4%

        \[\leadsto x - \color{blue}{\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}} \]
      7. associate-/l*90.4%

        \[\leadsto x - \color{blue}{\frac{y \cdot 2}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}}} \]
      8. associate-*l*90.4%

        \[\leadsto x - \frac{y \cdot 2}{\frac{\color{blue}{z \cdot \left(2 \cdot z\right)} - y \cdot t}{z}} \]
    3. Simplified90.4%

      \[\leadsto \color{blue}{x - \frac{y \cdot 2}{\frac{z \cdot \left(2 \cdot z\right) - y \cdot t}{z}}} \]
    4. Taylor expanded in y around inf 90.4%

      \[\leadsto x - \color{blue}{-2 \cdot \frac{z}{t}} \]
    5. Step-by-step derivation
      1. *-commutative90.4%

        \[\leadsto x - \color{blue}{\frac{z}{t} \cdot -2} \]
    6. Simplified90.4%

      \[\leadsto x - \color{blue}{\frac{z}{t} \cdot -2} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification91.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -3.3 \cdot 10^{+37} \lor \neg \left(z \leq 2.55 \cdot 10^{-36}\right):\\ \;\;\;\;x - \frac{y}{z}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{z}{t} \cdot -2\\ \end{array} \]

Alternative 5: 81.4% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -2.4 \cdot 10^{-73} \lor \neg \left(z \leq 2.55 \cdot 10^{-36}\right):\\ \;\;\;\;x - \frac{y}{z}\\ \mathbf{else}:\\ \;\;\;\;x\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (or (<= z -2.4e-73) (not (<= z 2.55e-36))) (- x (/ y z)) x))
double code(double x, double y, double z, double t) {
	double tmp;
	if ((z <= -2.4e-73) || !(z <= 2.55e-36)) {
		tmp = x - (y / z);
	} else {
		tmp = x;
	}
	return tmp;
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: tmp
    if ((z <= (-2.4d-73)) .or. (.not. (z <= 2.55d-36))) then
        tmp = x - (y / z)
    else
        tmp = x
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double tmp;
	if ((z <= -2.4e-73) || !(z <= 2.55e-36)) {
		tmp = x - (y / z);
	} else {
		tmp = x;
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if (z <= -2.4e-73) or not (z <= 2.55e-36):
		tmp = x - (y / z)
	else:
		tmp = x
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if ((z <= -2.4e-73) || !(z <= 2.55e-36))
		tmp = Float64(x - Float64(y / z));
	else
		tmp = x;
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	tmp = 0.0;
	if ((z <= -2.4e-73) || ~((z <= 2.55e-36)))
		tmp = x - (y / z);
	else
		tmp = x;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := If[Or[LessEqual[z, -2.4e-73], N[Not[LessEqual[z, 2.55e-36]], $MachinePrecision]], N[(x - N[(y / z), $MachinePrecision]), $MachinePrecision], x]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq -2.4 \cdot 10^{-73} \lor \neg \left(z \leq 2.55 \cdot 10^{-36}\right):\\
\;\;\;\;x - \frac{y}{z}\\

\mathbf{else}:\\
\;\;\;\;x\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -2.40000000000000006e-73 or 2.54999999999999987e-36 < z

    1. Initial program 73.4%

      \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
    2. Step-by-step derivation
      1. sub-neg73.4%

        \[\leadsto \color{blue}{x + \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
      2. associate-/l*86.4%

        \[\leadsto x + \left(-\color{blue}{\frac{y \cdot 2}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}}}\right) \]
      3. distribute-neg-frac86.4%

        \[\leadsto x + \color{blue}{\frac{-y \cdot 2}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}}} \]
      4. distribute-lft-neg-out86.4%

        \[\leadsto x + \frac{\color{blue}{\left(-y\right) \cdot 2}}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}} \]
      5. associate-/r/84.7%

        \[\leadsto x + \color{blue}{\frac{\left(-y\right) \cdot 2}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z} \]
      6. distribute-lft-neg-out84.7%

        \[\leadsto x + \frac{\color{blue}{-y \cdot 2}}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z \]
      7. distribute-rgt-neg-in84.7%

        \[\leadsto x + \frac{\color{blue}{y \cdot \left(-2\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z \]
      8. metadata-eval84.7%

        \[\leadsto x + \frac{y \cdot \color{blue}{-2}}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z \]
      9. *-commutative84.7%

        \[\leadsto x + \frac{y \cdot -2}{\color{blue}{\left(2 \cdot z\right)} \cdot z - y \cdot t} \cdot z \]
      10. associate-*l*84.7%

        \[\leadsto x + \frac{y \cdot -2}{\color{blue}{2 \cdot \left(z \cdot z\right)} - y \cdot t} \cdot z \]
      11. fma-neg84.7%

        \[\leadsto x + \frac{y \cdot -2}{\color{blue}{\mathsf{fma}\left(2, z \cdot z, -y \cdot t\right)}} \cdot z \]
    3. Simplified84.7%

      \[\leadsto \color{blue}{x + \frac{y \cdot -2}{\mathsf{fma}\left(2, z \cdot z, -y \cdot t\right)} \cdot z} \]
    4. Taylor expanded in y around 0 89.9%

      \[\leadsto \color{blue}{x + -1 \cdot \frac{y}{z}} \]
    5. Step-by-step derivation
      1. mul-1-neg89.9%

        \[\leadsto x + \color{blue}{\left(-\frac{y}{z}\right)} \]
      2. sub-neg89.9%

        \[\leadsto \color{blue}{x - \frac{y}{z}} \]
    6. Simplified89.9%

      \[\leadsto \color{blue}{x - \frac{y}{z}} \]

    if -2.40000000000000006e-73 < z < 2.54999999999999987e-36

    1. Initial program 86.7%

      \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
    2. Step-by-step derivation
      1. sub-neg86.7%

        \[\leadsto \color{blue}{x + \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
      2. associate-/l*89.0%

        \[\leadsto x + \left(-\color{blue}{\frac{y \cdot 2}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}}}\right) \]
      3. distribute-neg-frac89.0%

        \[\leadsto x + \color{blue}{\frac{-y \cdot 2}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}}} \]
      4. distribute-lft-neg-out89.0%

        \[\leadsto x + \frac{\color{blue}{\left(-y\right) \cdot 2}}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}} \]
      5. associate-/r/90.4%

        \[\leadsto x + \color{blue}{\frac{\left(-y\right) \cdot 2}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z} \]
      6. distribute-lft-neg-out90.4%

        \[\leadsto x + \frac{\color{blue}{-y \cdot 2}}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z \]
      7. distribute-rgt-neg-in90.4%

        \[\leadsto x + \frac{\color{blue}{y \cdot \left(-2\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z \]
      8. metadata-eval90.4%

        \[\leadsto x + \frac{y \cdot \color{blue}{-2}}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z \]
      9. *-commutative90.4%

        \[\leadsto x + \frac{y \cdot -2}{\color{blue}{\left(2 \cdot z\right)} \cdot z - y \cdot t} \cdot z \]
      10. associate-*l*90.4%

        \[\leadsto x + \frac{y \cdot -2}{\color{blue}{2 \cdot \left(z \cdot z\right)} - y \cdot t} \cdot z \]
      11. fma-neg90.4%

        \[\leadsto x + \frac{y \cdot -2}{\color{blue}{\mathsf{fma}\left(2, z \cdot z, -y \cdot t\right)}} \cdot z \]
    3. Simplified90.4%

      \[\leadsto \color{blue}{x + \frac{y \cdot -2}{\mathsf{fma}\left(2, z \cdot z, -y \cdot t\right)} \cdot z} \]
    4. Taylor expanded in x around inf 77.6%

      \[\leadsto \color{blue}{x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification84.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -2.4 \cdot 10^{-73} \lor \neg \left(z \leq 2.55 \cdot 10^{-36}\right):\\ \;\;\;\;x - \frac{y}{z}\\ \mathbf{else}:\\ \;\;\;\;x\\ \end{array} \]

Alternative 6: 75.5% accurate, 17.0× speedup?

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

\\
x
\end{array}
Derivation
  1. Initial program 79.4%

    \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
  2. Step-by-step derivation
    1. sub-neg79.4%

      \[\leadsto \color{blue}{x + \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
    2. associate-/l*87.6%

      \[\leadsto x + \left(-\color{blue}{\frac{y \cdot 2}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}}}\right) \]
    3. distribute-neg-frac87.6%

      \[\leadsto x + \color{blue}{\frac{-y \cdot 2}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}}} \]
    4. distribute-lft-neg-out87.6%

      \[\leadsto x + \frac{\color{blue}{\left(-y\right) \cdot 2}}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}} \]
    5. associate-/r/87.3%

      \[\leadsto x + \color{blue}{\frac{\left(-y\right) \cdot 2}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z} \]
    6. distribute-lft-neg-out87.3%

      \[\leadsto x + \frac{\color{blue}{-y \cdot 2}}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z \]
    7. distribute-rgt-neg-in87.3%

      \[\leadsto x + \frac{\color{blue}{y \cdot \left(-2\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z \]
    8. metadata-eval87.3%

      \[\leadsto x + \frac{y \cdot \color{blue}{-2}}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot z \]
    9. *-commutative87.3%

      \[\leadsto x + \frac{y \cdot -2}{\color{blue}{\left(2 \cdot z\right)} \cdot z - y \cdot t} \cdot z \]
    10. associate-*l*87.3%

      \[\leadsto x + \frac{y \cdot -2}{\color{blue}{2 \cdot \left(z \cdot z\right)} - y \cdot t} \cdot z \]
    11. fma-neg87.3%

      \[\leadsto x + \frac{y \cdot -2}{\color{blue}{\mathsf{fma}\left(2, z \cdot z, -y \cdot t\right)}} \cdot z \]
  3. Simplified87.3%

    \[\leadsto \color{blue}{x + \frac{y \cdot -2}{\mathsf{fma}\left(2, z \cdot z, -y \cdot t\right)} \cdot z} \]
  4. Taylor expanded in x around inf 75.1%

    \[\leadsto \color{blue}{x} \]
  5. Final simplification75.1%

    \[\leadsto x \]

Developer target: 99.9% accurate, 1.3× speedup?

\[\begin{array}{l} \\ x - \frac{1}{\frac{z}{y} - \frac{\frac{t}{2}}{z}} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (- x (/ 1.0 (- (/ z y) (/ (/ t 2.0) z)))))
double code(double x, double y, double z, double t) {
	return x - (1.0 / ((z / y) - ((t / 2.0) / z)));
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    code = x - (1.0d0 / ((z / y) - ((t / 2.0d0) / z)))
end function
public static double code(double x, double y, double z, double t) {
	return x - (1.0 / ((z / y) - ((t / 2.0) / z)));
}
def code(x, y, z, t):
	return x - (1.0 / ((z / y) - ((t / 2.0) / z)))
function code(x, y, z, t)
	return Float64(x - Float64(1.0 / Float64(Float64(z / y) - Float64(Float64(t / 2.0) / z))))
end
function tmp = code(x, y, z, t)
	tmp = x - (1.0 / ((z / y) - ((t / 2.0) / z)));
end
code[x_, y_, z_, t_] := N[(x - N[(1.0 / N[(N[(z / y), $MachinePrecision] - N[(N[(t / 2.0), $MachinePrecision] / z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x - \frac{1}{\frac{z}{y} - \frac{\frac{t}{2}}{z}}
\end{array}

Reproduce

?
herbie shell --seed 2023320 
(FPCore (x y z t)
  :name "Numeric.AD.Rank1.Halley:findZero from ad-4.2.4"
  :precision binary64

  :herbie-target
  (- x (/ 1.0 (- (/ z y) (/ (/ t 2.0) z))))

  (- x (/ (* (* y 2.0) z) (- (* (* z 2.0) z) (* y t)))))