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

Percentage Accurate: 81.7% → 98.3%
Time: 8.7s
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: 81.7% 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: 98.3% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(\frac{y}{z \cdot -2 + \frac{y}{\frac{z}{t}}}, 2, x\right) \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (fma (/ y (+ (* z -2.0) (/ y (/ z t)))) 2.0 x))
double code(double x, double y, double z, double t) {
	return fma((y / ((z * -2.0) + (y / (z / t)))), 2.0, x);
}
function code(x, y, z, t)
	return fma(Float64(y / Float64(Float64(z * -2.0) + Float64(y / Float64(z / t)))), 2.0, x)
end
code[x_, y_, z_, t_] := N[(N[(y / N[(N[(z * -2.0), $MachinePrecision] + N[(y / N[(z / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 2.0 + x), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(\frac{y}{z \cdot -2 + \frac{y}{\frac{z}{t}}}, 2, x\right)
\end{array}
Derivation
  1. Initial program 79.3%

    \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
  2. Simplified98.5%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{y}{z \cdot -2 + \frac{y}{\frac{z}{t}}}, 2, x\right)} \]
  3. Final simplification98.5%

    \[\leadsto \mathsf{fma}\left(\frac{y}{z \cdot -2 + \frac{y}{\frac{z}{t}}}, 2, x\right) \]

Alternative 2: 94.7% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{z \cdot \left(y \cdot 2\right)}{z \cdot \left(z \cdot 2\right) - y \cdot t} \leq 5 \cdot 10^{+193}:\\ \;\;\;\;x + \left(z \cdot -2\right) \cdot \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{y}{z}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= (/ (* z (* y 2.0)) (- (* z (* z 2.0)) (* y t))) 5e+193)
   (+ x (* (* z -2.0) (/ y (- (* 2.0 (* z z)) (* y t)))))
   (- x (/ y z))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (((z * (y * 2.0)) / ((z * (z * 2.0)) - (y * t))) <= 5e+193) {
		tmp = x + ((z * -2.0) * (y / ((2.0 * (z * z)) - (y * t))));
	} else {
		tmp = x - (y / z);
	}
	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 * (y * 2.0d0)) / ((z * (z * 2.0d0)) - (y * t))) <= 5d+193) then
        tmp = x + ((z * (-2.0d0)) * (y / ((2.0d0 * (z * z)) - (y * t))))
    else
        tmp = x - (y / z)
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (((z * (y * 2.0)) / ((z * (z * 2.0)) - (y * t))) <= 5e+193) {
		tmp = x + ((z * -2.0) * (y / ((2.0 * (z * z)) - (y * t))));
	} else {
		tmp = x - (y / z);
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if ((z * (y * 2.0)) / ((z * (z * 2.0)) - (y * t))) <= 5e+193:
		tmp = x + ((z * -2.0) * (y / ((2.0 * (z * z)) - (y * t))))
	else:
		tmp = x - (y / z)
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (Float64(Float64(z * Float64(y * 2.0)) / Float64(Float64(z * Float64(z * 2.0)) - Float64(y * t))) <= 5e+193)
		tmp = Float64(x + Float64(Float64(z * -2.0) * Float64(y / Float64(Float64(2.0 * Float64(z * z)) - Float64(y * t)))));
	else
		tmp = Float64(x - Float64(y / z));
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	tmp = 0.0;
	if (((z * (y * 2.0)) / ((z * (z * 2.0)) - (y * t))) <= 5e+193)
		tmp = x + ((z * -2.0) * (y / ((2.0 * (z * z)) - (y * t))));
	else
		tmp = x - (y / z);
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := If[LessEqual[N[(N[(z * N[(y * 2.0), $MachinePrecision]), $MachinePrecision] / N[(N[(z * N[(z * 2.0), $MachinePrecision]), $MachinePrecision] - N[(y * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 5e+193], N[(x + N[(N[(z * -2.0), $MachinePrecision] * N[(y / N[(N[(2.0 * N[(z * z), $MachinePrecision]), $MachinePrecision] - N[(y * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x - N[(y / z), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{z \cdot \left(y \cdot 2\right)}{z \cdot \left(z \cdot 2\right) - y \cdot t} \leq 5 \cdot 10^{+193}:\\
\;\;\;\;x + \left(z \cdot -2\right) \cdot \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t}\\

\mathbf{else}:\\
\;\;\;\;x - \frac{y}{z}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (*.f64 (*.f64 y 2) z) (-.f64 (*.f64 (*.f64 z 2) z) (*.f64 y t))) < 4.99999999999999972e193

    1. Initial program 94.3%

      \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
    2. Step-by-step derivation
      1. sub-neg94.3%

        \[\leadsto \color{blue}{x + \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
      2. associate-*l*94.3%

        \[\leadsto x + \left(-\frac{\color{blue}{y \cdot \left(2 \cdot z\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right) \]
      3. *-commutative94.3%

        \[\leadsto x + \left(-\frac{y \cdot \color{blue}{\left(z \cdot 2\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right) \]
      4. associate-*l/96.3%

        \[\leadsto x + \left(-\color{blue}{\frac{y}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot \left(z \cdot 2\right)}\right) \]
      5. distribute-rgt-neg-in96.3%

        \[\leadsto x + \color{blue}{\frac{y}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot \left(-z \cdot 2\right)} \]
      6. *-commutative96.3%

        \[\leadsto x + \frac{y}{\color{blue}{\left(2 \cdot z\right)} \cdot z - y \cdot t} \cdot \left(-z \cdot 2\right) \]
      7. associate-*l*96.3%

        \[\leadsto x + \frac{y}{\color{blue}{2 \cdot \left(z \cdot z\right)} - y \cdot t} \cdot \left(-z \cdot 2\right) \]
      8. distribute-rgt-neg-in96.3%

        \[\leadsto x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \color{blue}{\left(z \cdot \left(-2\right)\right)} \]
      9. metadata-eval96.3%

        \[\leadsto x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \left(z \cdot \color{blue}{-2}\right) \]
    3. Simplified96.3%

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

    if 4.99999999999999972e193 < (/.f64 (*.f64 (*.f64 y 2) z) (-.f64 (*.f64 (*.f64 z 2) z) (*.f64 y t)))

    1. Initial program 0.2%

      \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
    2. Step-by-step derivation
      1. sub-neg0.2%

        \[\leadsto \color{blue}{x + \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
      2. associate-*l*0.2%

        \[\leadsto x + \left(-\frac{\color{blue}{y \cdot \left(2 \cdot z\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right) \]
      3. *-commutative0.2%

        \[\leadsto x + \left(-\frac{y \cdot \color{blue}{\left(z \cdot 2\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right) \]
      4. associate-*l/45.3%

        \[\leadsto x + \left(-\color{blue}{\frac{y}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot \left(z \cdot 2\right)}\right) \]
      5. distribute-rgt-neg-in45.3%

        \[\leadsto x + \color{blue}{\frac{y}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot \left(-z \cdot 2\right)} \]
      6. *-commutative45.3%

        \[\leadsto x + \frac{y}{\color{blue}{\left(2 \cdot z\right)} \cdot z - y \cdot t} \cdot \left(-z \cdot 2\right) \]
      7. associate-*l*45.3%

        \[\leadsto x + \frac{y}{\color{blue}{2 \cdot \left(z \cdot z\right)} - y \cdot t} \cdot \left(-z \cdot 2\right) \]
      8. distribute-rgt-neg-in45.3%

        \[\leadsto x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \color{blue}{\left(z \cdot \left(-2\right)\right)} \]
      9. metadata-eval45.3%

        \[\leadsto x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \left(z \cdot \color{blue}{-2}\right) \]
    3. Simplified45.3%

      \[\leadsto \color{blue}{x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \left(z \cdot -2\right)} \]
    4. Taylor expanded in y around 0 86.4%

      \[\leadsto \color{blue}{x + -1 \cdot \frac{y}{z}} \]
    5. Step-by-step derivation
      1. mul-1-neg86.4%

        \[\leadsto x + \color{blue}{\left(-\frac{y}{z}\right)} \]
      2. sub-neg86.4%

        \[\leadsto \color{blue}{x - \frac{y}{z}} \]
    6. Simplified86.4%

      \[\leadsto \color{blue}{x - \frac{y}{z}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification94.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{z \cdot \left(y \cdot 2\right)}{z \cdot \left(z \cdot 2\right) - y \cdot t} \leq 5 \cdot 10^{+193}:\\ \;\;\;\;x + \left(z \cdot -2\right) \cdot \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{y}{z}\\ \end{array} \]

Alternative 3: 89.0% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -4 \cdot 10^{+59} \lor \neg \left(z \leq 7.5 \cdot 10^{-16}\right):\\ \;\;\;\;x - \frac{y}{z}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{-2}{\frac{t}{z}}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (or (<= z -4e+59) (not (<= z 7.5e-16)))
   (- x (/ y z))
   (- x (/ -2.0 (/ t z)))))
double code(double x, double y, double z, double t) {
	double tmp;
	if ((z <= -4e+59) || !(z <= 7.5e-16)) {
		tmp = x - (y / z);
	} else {
		tmp = x - (-2.0 / (t / z));
	}
	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 <= (-4d+59)) .or. (.not. (z <= 7.5d-16))) then
        tmp = x - (y / z)
    else
        tmp = x - ((-2.0d0) / (t / z))
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double tmp;
	if ((z <= -4e+59) || !(z <= 7.5e-16)) {
		tmp = x - (y / z);
	} else {
		tmp = x - (-2.0 / (t / z));
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if (z <= -4e+59) or not (z <= 7.5e-16):
		tmp = x - (y / z)
	else:
		tmp = x - (-2.0 / (t / z))
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if ((z <= -4e+59) || !(z <= 7.5e-16))
		tmp = Float64(x - Float64(y / z));
	else
		tmp = Float64(x - Float64(-2.0 / Float64(t / z)));
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	tmp = 0.0;
	if ((z <= -4e+59) || ~((z <= 7.5e-16)))
		tmp = x - (y / z);
	else
		tmp = x - (-2.0 / (t / z));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := If[Or[LessEqual[z, -4e+59], N[Not[LessEqual[z, 7.5e-16]], $MachinePrecision]], N[(x - N[(y / z), $MachinePrecision]), $MachinePrecision], N[(x - N[(-2.0 / N[(t / z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq -4 \cdot 10^{+59} \lor \neg \left(z \leq 7.5 \cdot 10^{-16}\right):\\
\;\;\;\;x - \frac{y}{z}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -3.99999999999999989e59 or 7.5e-16 < z

    1. Initial program 62.6%

      \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
    2. Step-by-step derivation
      1. sub-neg62.6%

        \[\leadsto \color{blue}{x + \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
      2. associate-*l*62.6%

        \[\leadsto x + \left(-\frac{\color{blue}{y \cdot \left(2 \cdot z\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right) \]
      3. *-commutative62.6%

        \[\leadsto x + \left(-\frac{y \cdot \color{blue}{\left(z \cdot 2\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right) \]
      4. associate-*l/80.0%

        \[\leadsto x + \left(-\color{blue}{\frac{y}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot \left(z \cdot 2\right)}\right) \]
      5. distribute-rgt-neg-in80.0%

        \[\leadsto x + \color{blue}{\frac{y}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot \left(-z \cdot 2\right)} \]
      6. *-commutative80.0%

        \[\leadsto x + \frac{y}{\color{blue}{\left(2 \cdot z\right)} \cdot z - y \cdot t} \cdot \left(-z \cdot 2\right) \]
      7. associate-*l*80.0%

        \[\leadsto x + \frac{y}{\color{blue}{2 \cdot \left(z \cdot z\right)} - y \cdot t} \cdot \left(-z \cdot 2\right) \]
      8. distribute-rgt-neg-in80.0%

        \[\leadsto x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \color{blue}{\left(z \cdot \left(-2\right)\right)} \]
      9. metadata-eval80.0%

        \[\leadsto x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \left(z \cdot \color{blue}{-2}\right) \]
    3. Simplified80.0%

      \[\leadsto \color{blue}{x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \left(z \cdot -2\right)} \]
    4. Taylor expanded in y around 0 90.5%

      \[\leadsto \color{blue}{x + -1 \cdot \frac{y}{z}} \]
    5. Step-by-step derivation
      1. mul-1-neg90.5%

        \[\leadsto x + \color{blue}{\left(-\frac{y}{z}\right)} \]
      2. sub-neg90.5%

        \[\leadsto \color{blue}{x - \frac{y}{z}} \]
    6. Simplified90.5%

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

    if -3.99999999999999989e59 < z < 7.5e-16

    1. Initial program 94.4%

      \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
    2. Step-by-step derivation
      1. associate-/l*94.1%

        \[\leadsto x - \color{blue}{\frac{y \cdot 2}{\frac{\left(z \cdot 2\right) \cdot z - y \cdot t}{z}}} \]
      2. associate-*l*94.1%

        \[\leadsto x - \frac{y \cdot 2}{\frac{\color{blue}{z \cdot \left(2 \cdot z\right)} - y \cdot t}{z}} \]
    3. Simplified94.1%

      \[\leadsto \color{blue}{x - \frac{y \cdot 2}{\frac{z \cdot \left(2 \cdot z\right) - y \cdot t}{z}}} \]
    4. Taylor expanded in z around 0 83.2%

      \[\leadsto x - \frac{y \cdot 2}{\color{blue}{-1 \cdot \frac{t \cdot y}{z}}} \]
    5. Step-by-step derivation
      1. associate-*r/83.2%

        \[\leadsto x - \frac{y \cdot 2}{\color{blue}{\frac{-1 \cdot \left(t \cdot y\right)}{z}}} \]
      2. mul-1-neg83.2%

        \[\leadsto x - \frac{y \cdot 2}{\frac{\color{blue}{-t \cdot y}}{z}} \]
      3. *-commutative83.2%

        \[\leadsto x - \frac{y \cdot 2}{\frac{-\color{blue}{y \cdot t}}{z}} \]
      4. distribute-rgt-neg-in83.2%

        \[\leadsto x - \frac{y \cdot 2}{\frac{\color{blue}{y \cdot \left(-t\right)}}{z}} \]
    6. Simplified83.2%

      \[\leadsto x - \frac{y \cdot 2}{\color{blue}{\frac{y \cdot \left(-t\right)}{z}}} \]
    7. Taylor expanded in y around 0 90.5%

      \[\leadsto x - \color{blue}{-2 \cdot \frac{z}{t}} \]
    8. Step-by-step derivation
      1. *-lft-identity90.5%

        \[\leadsto x - -2 \cdot \frac{\color{blue}{1 \cdot z}}{t} \]
      2. associate-*l/90.3%

        \[\leadsto x - -2 \cdot \color{blue}{\left(\frac{1}{t} \cdot z\right)} \]
      3. *-inverses90.3%

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

        \[\leadsto x - -2 \cdot \left(\color{blue}{\frac{y}{y \cdot t}} \cdot z\right) \]
      5. *-commutative84.5%

        \[\leadsto x - -2 \cdot \left(\frac{y}{\color{blue}{t \cdot y}} \cdot z\right) \]
      6. associate-*l/84.1%

        \[\leadsto x - -2 \cdot \color{blue}{\frac{y \cdot z}{t \cdot y}} \]
      7. /-rgt-identity84.1%

        \[\leadsto x - -2 \cdot \frac{\color{blue}{\frac{y}{1}} \cdot z}{t \cdot y} \]
      8. associate-/r/84.1%

        \[\leadsto x - -2 \cdot \frac{\color{blue}{\frac{y}{\frac{1}{z}}}}{t \cdot y} \]
      9. metadata-eval84.1%

        \[\leadsto x - \color{blue}{\left(-2\right)} \cdot \frac{\frac{y}{\frac{1}{z}}}{t \cdot y} \]
      10. associate-/r*83.2%

        \[\leadsto x - \left(-2\right) \cdot \color{blue}{\frac{y}{\frac{1}{z} \cdot \left(t \cdot y\right)}} \]
      11. associate-*l/83.2%

        \[\leadsto x - \left(-2\right) \cdot \frac{y}{\color{blue}{\frac{1 \cdot \left(t \cdot y\right)}{z}}} \]
      12. *-lft-identity83.2%

        \[\leadsto x - \left(-2\right) \cdot \frac{y}{\frac{\color{blue}{t \cdot y}}{z}} \]
      13. associate-*l/88.2%

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

        \[\leadsto x - \left(-2\right) \cdot \frac{y}{\color{blue}{y \cdot \frac{t}{z}}} \]
      15. distribute-lft-neg-in88.2%

        \[\leadsto x - \color{blue}{\left(-2 \cdot \frac{y}{y \cdot \frac{t}{z}}\right)} \]
      16. associate-*r/88.2%

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

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

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

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

      \[\leadsto x - \color{blue}{\frac{-2}{\frac{t}{z}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification90.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -4 \cdot 10^{+59} \lor \neg \left(z \leq 7.5 \cdot 10^{-16}\right):\\ \;\;\;\;x - \frac{y}{z}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{-2}{\frac{t}{z}}\\ \end{array} \]

Alternative 4: 89.0% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -1 \cdot 10^{+59} \lor \neg \left(z \leq 7.8 \cdot 10^{-17}\right):\\ \;\;\;\;x - \frac{y}{z}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{z \cdot -2}{t}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (or (<= z -1e+59) (not (<= z 7.8e-17)))
   (- x (/ y z))
   (- x (/ (* z -2.0) t))))
double code(double x, double y, double z, double t) {
	double tmp;
	if ((z <= -1e+59) || !(z <= 7.8e-17)) {
		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 <= (-1d+59)) .or. (.not. (z <= 7.8d-17))) 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 <= -1e+59) || !(z <= 7.8e-17)) {
		tmp = x - (y / z);
	} else {
		tmp = x - ((z * -2.0) / t);
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if (z <= -1e+59) or not (z <= 7.8e-17):
		tmp = x - (y / z)
	else:
		tmp = x - ((z * -2.0) / t)
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if ((z <= -1e+59) || !(z <= 7.8e-17))
		tmp = Float64(x - Float64(y / z));
	else
		tmp = Float64(x - Float64(Float64(z * -2.0) / t));
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	tmp = 0.0;
	if ((z <= -1e+59) || ~((z <= 7.8e-17)))
		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, -1e+59], N[Not[LessEqual[z, 7.8e-17]], $MachinePrecision]], N[(x - N[(y / z), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[(z * -2.0), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq -1 \cdot 10^{+59} \lor \neg \left(z \leq 7.8 \cdot 10^{-17}\right):\\
\;\;\;\;x - \frac{y}{z}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -9.99999999999999972e58 or 7.79999999999999979e-17 < z

    1. Initial program 62.6%

      \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
    2. Step-by-step derivation
      1. sub-neg62.6%

        \[\leadsto \color{blue}{x + \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
      2. associate-*l*62.6%

        \[\leadsto x + \left(-\frac{\color{blue}{y \cdot \left(2 \cdot z\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right) \]
      3. *-commutative62.6%

        \[\leadsto x + \left(-\frac{y \cdot \color{blue}{\left(z \cdot 2\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right) \]
      4. associate-*l/80.0%

        \[\leadsto x + \left(-\color{blue}{\frac{y}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot \left(z \cdot 2\right)}\right) \]
      5. distribute-rgt-neg-in80.0%

        \[\leadsto x + \color{blue}{\frac{y}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot \left(-z \cdot 2\right)} \]
      6. *-commutative80.0%

        \[\leadsto x + \frac{y}{\color{blue}{\left(2 \cdot z\right)} \cdot z - y \cdot t} \cdot \left(-z \cdot 2\right) \]
      7. associate-*l*80.0%

        \[\leadsto x + \frac{y}{\color{blue}{2 \cdot \left(z \cdot z\right)} - y \cdot t} \cdot \left(-z \cdot 2\right) \]
      8. distribute-rgt-neg-in80.0%

        \[\leadsto x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \color{blue}{\left(z \cdot \left(-2\right)\right)} \]
      9. metadata-eval80.0%

        \[\leadsto x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \left(z \cdot \color{blue}{-2}\right) \]
    3. Simplified80.0%

      \[\leadsto \color{blue}{x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \left(z \cdot -2\right)} \]
    4. Taylor expanded in y around 0 90.5%

      \[\leadsto \color{blue}{x + -1 \cdot \frac{y}{z}} \]
    5. Step-by-step derivation
      1. mul-1-neg90.5%

        \[\leadsto x + \color{blue}{\left(-\frac{y}{z}\right)} \]
      2. sub-neg90.5%

        \[\leadsto \color{blue}{x - \frac{y}{z}} \]
    6. Simplified90.5%

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

    if -9.99999999999999972e58 < z < 7.79999999999999979e-17

    1. Initial program 94.4%

      \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
    2. Step-by-step derivation
      1. sub-neg94.4%

        \[\leadsto \color{blue}{x + \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
      2. associate-*l*94.4%

        \[\leadsto x + \left(-\frac{\color{blue}{y \cdot \left(2 \cdot z\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right) \]
      3. *-commutative94.4%

        \[\leadsto x + \left(-\frac{y \cdot \color{blue}{\left(z \cdot 2\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right) \]
      4. associate-*l/95.4%

        \[\leadsto x + \left(-\color{blue}{\frac{y}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot \left(z \cdot 2\right)}\right) \]
      5. distribute-rgt-neg-in95.4%

        \[\leadsto x + \color{blue}{\frac{y}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot \left(-z \cdot 2\right)} \]
      6. *-commutative95.4%

        \[\leadsto x + \frac{y}{\color{blue}{\left(2 \cdot z\right)} \cdot z - y \cdot t} \cdot \left(-z \cdot 2\right) \]
      7. associate-*l*95.4%

        \[\leadsto x + \frac{y}{\color{blue}{2 \cdot \left(z \cdot z\right)} - y \cdot t} \cdot \left(-z \cdot 2\right) \]
      8. distribute-rgt-neg-in95.4%

        \[\leadsto x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \color{blue}{\left(z \cdot \left(-2\right)\right)} \]
      9. metadata-eval95.4%

        \[\leadsto x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \left(z \cdot \color{blue}{-2}\right) \]
    3. Simplified95.4%

      \[\leadsto \color{blue}{x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \left(z \cdot -2\right)} \]
    4. Taylor expanded in y around inf 90.5%

      \[\leadsto \color{blue}{x + 2 \cdot \frac{z}{t}} \]
    5. Step-by-step derivation
      1. metadata-eval90.5%

        \[\leadsto x + \color{blue}{\left(--2\right)} \cdot \frac{z}{t} \]
      2. cancel-sign-sub-inv90.5%

        \[\leadsto \color{blue}{x - -2 \cdot \frac{z}{t}} \]
      3. associate-*r/90.5%

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

        \[\leadsto x - \frac{\color{blue}{z \cdot -2}}{t} \]
    6. Simplified90.5%

      \[\leadsto \color{blue}{x - \frac{z \cdot -2}{t}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification90.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -1 \cdot 10^{+59} \lor \neg \left(z \leq 7.8 \cdot 10^{-17}\right):\\ \;\;\;\;x - \frac{y}{z}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{z \cdot -2}{t}\\ \end{array} \]

Alternative 5: 81.5% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -4.2 \cdot 10^{-47} \lor \neg \left(z \leq 2.3 \cdot 10^{-26}\right):\\ \;\;\;\;x - \frac{y}{z}\\ \mathbf{else}:\\ \;\;\;\;x\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (or (<= z -4.2e-47) (not (<= z 2.3e-26))) (- x (/ y z)) x))
double code(double x, double y, double z, double t) {
	double tmp;
	if ((z <= -4.2e-47) || !(z <= 2.3e-26)) {
		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 <= (-4.2d-47)) .or. (.not. (z <= 2.3d-26))) 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 <= -4.2e-47) || !(z <= 2.3e-26)) {
		tmp = x - (y / z);
	} else {
		tmp = x;
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if (z <= -4.2e-47) or not (z <= 2.3e-26):
		tmp = x - (y / z)
	else:
		tmp = x
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if ((z <= -4.2e-47) || !(z <= 2.3e-26))
		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 <= -4.2e-47) || ~((z <= 2.3e-26)))
		tmp = x - (y / z);
	else
		tmp = x;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := If[Or[LessEqual[z, -4.2e-47], N[Not[LessEqual[z, 2.3e-26]], $MachinePrecision]], N[(x - N[(y / z), $MachinePrecision]), $MachinePrecision], x]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq -4.2 \cdot 10^{-47} \lor \neg \left(z \leq 2.3 \cdot 10^{-26}\right):\\
\;\;\;\;x - \frac{y}{z}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -4.2000000000000001e-47 or 2.30000000000000009e-26 < z

    1. Initial program 68.3%

      \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
    2. Step-by-step derivation
      1. sub-neg68.3%

        \[\leadsto \color{blue}{x + \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
      2. associate-*l*68.3%

        \[\leadsto x + \left(-\frac{\color{blue}{y \cdot \left(2 \cdot z\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right) \]
      3. *-commutative68.3%

        \[\leadsto x + \left(-\frac{y \cdot \color{blue}{\left(z \cdot 2\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right) \]
      4. associate-*l/82.7%

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

        \[\leadsto x + \color{blue}{\frac{y}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot \left(-z \cdot 2\right)} \]
      6. *-commutative82.7%

        \[\leadsto x + \frac{y}{\color{blue}{\left(2 \cdot z\right)} \cdot z - y \cdot t} \cdot \left(-z \cdot 2\right) \]
      7. associate-*l*82.7%

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

        \[\leadsto x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \color{blue}{\left(z \cdot \left(-2\right)\right)} \]
      9. metadata-eval82.7%

        \[\leadsto x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \left(z \cdot \color{blue}{-2}\right) \]
    3. Simplified82.7%

      \[\leadsto \color{blue}{x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \left(z \cdot -2\right)} \]
    4. Taylor expanded in y around 0 84.6%

      \[\leadsto \color{blue}{x + -1 \cdot \frac{y}{z}} \]
    5. Step-by-step derivation
      1. mul-1-neg84.6%

        \[\leadsto x + \color{blue}{\left(-\frac{y}{z}\right)} \]
      2. sub-neg84.6%

        \[\leadsto \color{blue}{x - \frac{y}{z}} \]
    6. Simplified84.6%

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

    if -4.2000000000000001e-47 < z < 2.30000000000000009e-26

    1. Initial program 94.0%

      \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
    2. Step-by-step derivation
      1. sub-neg94.0%

        \[\leadsto \color{blue}{x + \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
      2. associate-*l*94.0%

        \[\leadsto x + \left(-\frac{\color{blue}{y \cdot \left(2 \cdot z\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right) \]
      3. *-commutative94.0%

        \[\leadsto x + \left(-\frac{y \cdot \color{blue}{\left(z \cdot 2\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right) \]
      4. associate-*l/95.3%

        \[\leadsto x + \left(-\color{blue}{\frac{y}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot \left(z \cdot 2\right)}\right) \]
      5. distribute-rgt-neg-in95.3%

        \[\leadsto x + \color{blue}{\frac{y}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot \left(-z \cdot 2\right)} \]
      6. *-commutative95.3%

        \[\leadsto x + \frac{y}{\color{blue}{\left(2 \cdot z\right)} \cdot z - y \cdot t} \cdot \left(-z \cdot 2\right) \]
      7. associate-*l*95.3%

        \[\leadsto x + \frac{y}{\color{blue}{2 \cdot \left(z \cdot z\right)} - y \cdot t} \cdot \left(-z \cdot 2\right) \]
      8. distribute-rgt-neg-in95.3%

        \[\leadsto x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \color{blue}{\left(z \cdot \left(-2\right)\right)} \]
      9. metadata-eval95.3%

        \[\leadsto x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \left(z \cdot \color{blue}{-2}\right) \]
    3. Simplified95.3%

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

      \[\leadsto \color{blue}{x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification81.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -4.2 \cdot 10^{-47} \lor \neg \left(z \leq 2.3 \cdot 10^{-26}\right):\\ \;\;\;\;x - \frac{y}{z}\\ \mathbf{else}:\\ \;\;\;\;x\\ \end{array} \]

Alternative 6: 74.9% 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 79.3%

    \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
  2. Step-by-step derivation
    1. sub-neg79.3%

      \[\leadsto \color{blue}{x + \left(-\frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right)} \]
    2. associate-*l*79.3%

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

      \[\leadsto x + \left(-\frac{y \cdot \color{blue}{\left(z \cdot 2\right)}}{\left(z \cdot 2\right) \cdot z - y \cdot t}\right) \]
    4. associate-*l/88.1%

      \[\leadsto x + \left(-\color{blue}{\frac{y}{\left(z \cdot 2\right) \cdot z - y \cdot t} \cdot \left(z \cdot 2\right)}\right) \]
    5. distribute-rgt-neg-in88.1%

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

      \[\leadsto x + \frac{y}{\color{blue}{\left(2 \cdot z\right)} \cdot z - y \cdot t} \cdot \left(-z \cdot 2\right) \]
    7. associate-*l*88.1%

      \[\leadsto x + \frac{y}{\color{blue}{2 \cdot \left(z \cdot z\right)} - y \cdot t} \cdot \left(-z \cdot 2\right) \]
    8. distribute-rgt-neg-in88.1%

      \[\leadsto x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \color{blue}{\left(z \cdot \left(-2\right)\right)} \]
    9. metadata-eval88.1%

      \[\leadsto x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \left(z \cdot \color{blue}{-2}\right) \]
  3. Simplified88.1%

    \[\leadsto \color{blue}{x + \frac{y}{2 \cdot \left(z \cdot z\right) - y \cdot t} \cdot \left(z \cdot -2\right)} \]
  4. Taylor expanded in x around inf 71.7%

    \[\leadsto \color{blue}{x} \]
  5. Final simplification71.7%

    \[\leadsto x \]

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 2023310 
(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)))))