Data.Number.Erf:$cinvnormcdf from erf-2.0.0.0, A

Percentage Accurate: 99.4% → 99.8%
Time: 36.3s
Alternatives: 12
Speedup: 1.1×

Specification

?
\[\begin{array}{l} \\ \left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (* (* (- (* x 0.5) y) (sqrt (* z 2.0))) (exp (/ (* t t) 2.0))))
double code(double x, double y, double z, double t) {
	return (((x * 0.5) - y) * sqrt((z * 2.0))) * exp(((t * t) / 2.0));
}
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 * 0.5d0) - y) * sqrt((z * 2.0d0))) * exp(((t * t) / 2.0d0))
end function
public static double code(double x, double y, double z, double t) {
	return (((x * 0.5) - y) * Math.sqrt((z * 2.0))) * Math.exp(((t * t) / 2.0));
}
def code(x, y, z, t):
	return (((x * 0.5) - y) * math.sqrt((z * 2.0))) * math.exp(((t * t) / 2.0))
function code(x, y, z, t)
	return Float64(Float64(Float64(Float64(x * 0.5) - y) * sqrt(Float64(z * 2.0))) * exp(Float64(Float64(t * t) / 2.0)))
end
function tmp = code(x, y, z, t)
	tmp = (((x * 0.5) - y) * sqrt((z * 2.0))) * exp(((t * t) / 2.0));
end
code[x_, y_, z_, t_] := N[(N[(N[(N[(x * 0.5), $MachinePrecision] - y), $MachinePrecision] * N[Sqrt[N[(z * 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[Exp[N[(N[(t * t), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 12 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 99.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (* (* (- (* x 0.5) y) (sqrt (* z 2.0))) (exp (/ (* t t) 2.0))))
double code(double x, double y, double z, double t) {
	return (((x * 0.5) - y) * sqrt((z * 2.0))) * exp(((t * t) / 2.0));
}
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 * 0.5d0) - y) * sqrt((z * 2.0d0))) * exp(((t * t) / 2.0d0))
end function
public static double code(double x, double y, double z, double t) {
	return (((x * 0.5) - y) * Math.sqrt((z * 2.0))) * Math.exp(((t * t) / 2.0));
}
def code(x, y, z, t):
	return (((x * 0.5) - y) * math.sqrt((z * 2.0))) * math.exp(((t * t) / 2.0))
function code(x, y, z, t)
	return Float64(Float64(Float64(Float64(x * 0.5) - y) * sqrt(Float64(z * 2.0))) * exp(Float64(Float64(t * t) / 2.0)))
end
function tmp = code(x, y, z, t)
	tmp = (((x * 0.5) - y) * sqrt((z * 2.0))) * exp(((t * t) / 2.0));
end
code[x_, y_, z_, t_] := N[(N[(N[(N[(x * 0.5), $MachinePrecision] - y), $MachinePrecision] * N[Sqrt[N[(z * 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[Exp[N[(N[(t * t), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}}
\end{array}

Alternative 1: 99.8% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \left(x \cdot 0.5 - y\right) \cdot \sqrt{2 \cdot \left(z \cdot e^{t \cdot t}\right)} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (* (- (* x 0.5) y) (sqrt (* 2.0 (* z (exp (* t t)))))))
double code(double x, double y, double z, double t) {
	return ((x * 0.5) - y) * sqrt((2.0 * (z * exp((t * 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 * 0.5d0) - y) * sqrt((2.0d0 * (z * exp((t * t)))))
end function
public static double code(double x, double y, double z, double t) {
	return ((x * 0.5) - y) * Math.sqrt((2.0 * (z * Math.exp((t * t)))));
}
def code(x, y, z, t):
	return ((x * 0.5) - y) * math.sqrt((2.0 * (z * math.exp((t * t)))))
function code(x, y, z, t)
	return Float64(Float64(Float64(x * 0.5) - y) * sqrt(Float64(2.0 * Float64(z * exp(Float64(t * t))))))
end
function tmp = code(x, y, z, t)
	tmp = ((x * 0.5) - y) * sqrt((2.0 * (z * exp((t * t)))));
end
code[x_, y_, z_, t_] := N[(N[(N[(x * 0.5), $MachinePrecision] - y), $MachinePrecision] * N[Sqrt[N[(2.0 * N[(z * N[Exp[N[(t * t), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(x \cdot 0.5 - y\right) \cdot \sqrt{2 \cdot \left(z \cdot e^{t \cdot t}\right)}
\end{array}
Derivation
  1. Initial program 98.6%

    \[\left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{\left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}}} \]
    2. lift-*.f64N/A

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

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

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

      \[\leadsto \left(x \cdot \frac{1}{2} - y\right) \cdot \left(\color{blue}{\sqrt{z \cdot 2}} \cdot e^{\frac{t \cdot t}{2}}\right) \]
    6. lift-exp.f64N/A

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

      \[\leadsto \left(x \cdot \frac{1}{2} - y\right) \cdot \left(\sqrt{z \cdot 2} \cdot e^{\color{blue}{\frac{t \cdot t}{2}}}\right) \]
    8. exp-sqrtN/A

      \[\leadsto \left(x \cdot \frac{1}{2} - y\right) \cdot \left(\sqrt{z \cdot 2} \cdot \color{blue}{\sqrt{e^{t \cdot t}}}\right) \]
    9. sqrt-unprodN/A

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

      \[\leadsto \left(x \cdot \frac{1}{2} - y\right) \cdot \color{blue}{\sqrt{\left(z \cdot 2\right) \cdot e^{t \cdot t}}} \]
    11. lift-*.f64N/A

      \[\leadsto \left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{\color{blue}{\left(z \cdot 2\right)} \cdot e^{t \cdot t}} \]
    12. *-commutativeN/A

      \[\leadsto \left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{\color{blue}{\left(2 \cdot z\right)} \cdot e^{t \cdot t}} \]
    13. associate-*l*N/A

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

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

      \[\leadsto \left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{2 \cdot \color{blue}{\left(z \cdot e^{t \cdot t}\right)}} \]
    16. lower-exp.f6499.8

      \[\leadsto \left(x \cdot 0.5 - y\right) \cdot \sqrt{2 \cdot \left(z \cdot \color{blue}{e^{t \cdot t}}\right)} \]
  4. Applied rewrites99.8%

    \[\leadsto \color{blue}{\left(x \cdot 0.5 - y\right) \cdot \sqrt{2 \cdot \left(z \cdot e^{t \cdot t}\right)}} \]
  5. Add Preprocessing

Alternative 2: 88.6% accurate, 2.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \mathsf{fma}\left(t, 0.5 \cdot t, 1\right)\\ t_2 := \sqrt{2 \cdot z}\\ t_3 := x \cdot 0.5 - y\\ \mathbf{if}\;t \cdot t \leq 5 \cdot 10^{+139}:\\ \;\;\;\;t\_2 \cdot \left(t\_3 \cdot t\_1\right)\\ \mathbf{elif}\;t \cdot t \leq 10^{+254}:\\ \;\;\;\;\left(y \cdot \mathsf{fma}\left(t \cdot t, \mathsf{fma}\left(t, t \cdot 0.125, 0.5\right), 1\right)\right) \cdot \left(-t\_2\right)\\ \mathbf{else}:\\ \;\;\;\;t\_3 \cdot \left(t\_2 \cdot t\_1\right)\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (fma t (* 0.5 t) 1.0))
        (t_2 (sqrt (* 2.0 z)))
        (t_3 (- (* x 0.5) y)))
   (if (<= (* t t) 5e+139)
     (* t_2 (* t_3 t_1))
     (if (<= (* t t) 1e+254)
       (* (* y (fma (* t t) (fma t (* t 0.125) 0.5) 1.0)) (- t_2))
       (* t_3 (* t_2 t_1))))))
double code(double x, double y, double z, double t) {
	double t_1 = fma(t, (0.5 * t), 1.0);
	double t_2 = sqrt((2.0 * z));
	double t_3 = (x * 0.5) - y;
	double tmp;
	if ((t * t) <= 5e+139) {
		tmp = t_2 * (t_3 * t_1);
	} else if ((t * t) <= 1e+254) {
		tmp = (y * fma((t * t), fma(t, (t * 0.125), 0.5), 1.0)) * -t_2;
	} else {
		tmp = t_3 * (t_2 * t_1);
	}
	return tmp;
}
function code(x, y, z, t)
	t_1 = fma(t, Float64(0.5 * t), 1.0)
	t_2 = sqrt(Float64(2.0 * z))
	t_3 = Float64(Float64(x * 0.5) - y)
	tmp = 0.0
	if (Float64(t * t) <= 5e+139)
		tmp = Float64(t_2 * Float64(t_3 * t_1));
	elseif (Float64(t * t) <= 1e+254)
		tmp = Float64(Float64(y * fma(Float64(t * t), fma(t, Float64(t * 0.125), 0.5), 1.0)) * Float64(-t_2));
	else
		tmp = Float64(t_3 * Float64(t_2 * t_1));
	end
	return tmp
end
code[x_, y_, z_, t_] := Block[{t$95$1 = N[(t * N[(0.5 * t), $MachinePrecision] + 1.0), $MachinePrecision]}, Block[{t$95$2 = N[Sqrt[N[(2.0 * z), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$3 = N[(N[(x * 0.5), $MachinePrecision] - y), $MachinePrecision]}, If[LessEqual[N[(t * t), $MachinePrecision], 5e+139], N[(t$95$2 * N[(t$95$3 * t$95$1), $MachinePrecision]), $MachinePrecision], If[LessEqual[N[(t * t), $MachinePrecision], 1e+254], N[(N[(y * N[(N[(t * t), $MachinePrecision] * N[(t * N[(t * 0.125), $MachinePrecision] + 0.5), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision] * (-t$95$2)), $MachinePrecision], N[(t$95$3 * N[(t$95$2 * t$95$1), $MachinePrecision]), $MachinePrecision]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \mathsf{fma}\left(t, 0.5 \cdot t, 1\right)\\
t_2 := \sqrt{2 \cdot z}\\
t_3 := x \cdot 0.5 - y\\
\mathbf{if}\;t \cdot t \leq 5 \cdot 10^{+139}:\\
\;\;\;\;t\_2 \cdot \left(t\_3 \cdot t\_1\right)\\

\mathbf{elif}\;t \cdot t \leq 10^{+254}:\\
\;\;\;\;\left(y \cdot \mathsf{fma}\left(t \cdot t, \mathsf{fma}\left(t, t \cdot 0.125, 0.5\right), 1\right)\right) \cdot \left(-t\_2\right)\\

\mathbf{else}:\\
\;\;\;\;t\_3 \cdot \left(t\_2 \cdot t\_1\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 t t) < 5.0000000000000003e139

    1. Initial program 99.6%

      \[\left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}} \]
    2. Add Preprocessing
    3. Taylor expanded in t around 0

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

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

        \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \color{blue}{\mathsf{fma}\left({t}^{2}, \frac{1}{2} + \frac{1}{8} \cdot {t}^{2}, 1\right)} \]
      3. unpow2N/A

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

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

        \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(t \cdot t, \color{blue}{\frac{1}{8} \cdot {t}^{2} + \frac{1}{2}}, 1\right) \]
      6. unpow2N/A

        \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(t \cdot t, \frac{1}{8} \cdot \color{blue}{\left(t \cdot t\right)} + \frac{1}{2}, 1\right) \]
      7. associate-*r*N/A

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

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

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

        \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(t \cdot t, \mathsf{fma}\left(t, \color{blue}{t \cdot \frac{1}{8}}, \frac{1}{2}\right), 1\right) \]
      11. lower-*.f6488.7

        \[\leadsto \left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(t \cdot t, \mathsf{fma}\left(t, \color{blue}{t \cdot 0.125}, 0.5\right), 1\right) \]
    5. Applied rewrites88.7%

      \[\leadsto \left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \color{blue}{\mathsf{fma}\left(t \cdot t, \mathsf{fma}\left(t, t \cdot 0.125, 0.5\right), 1\right)} \]
    6. Step-by-step derivation
      1. lift-*.f64N/A

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

        \[\leadsto \color{blue}{\left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right)} \cdot \mathsf{fma}\left(t \cdot t, \mathsf{fma}\left(t, t \cdot \frac{1}{8}, \frac{1}{2}\right), 1\right) \]
      3. associate-*l*N/A

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

        \[\leadsto \left(x \cdot \frac{1}{2} - y\right) \cdot \color{blue}{\left(\mathsf{fma}\left(t \cdot t, \mathsf{fma}\left(t, t \cdot \frac{1}{8}, \frac{1}{2}\right), 1\right) \cdot \sqrt{z \cdot 2}\right)} \]
      5. associate-*r*N/A

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

        \[\leadsto \color{blue}{\left(\left(x \cdot \frac{1}{2} - y\right) \cdot \mathsf{fma}\left(t \cdot t, \mathsf{fma}\left(t, t \cdot \frac{1}{8}, \frac{1}{2}\right), 1\right)\right) \cdot \sqrt{z \cdot 2}} \]
    7. Applied rewrites90.1%

      \[\leadsto \color{blue}{\left(\left(x \cdot 0.5 - y\right) \cdot \mathsf{fma}\left(t, t \cdot \mathsf{fma}\left(t \cdot t, 0.125, 0.5\right), 1\right)\right) \cdot \sqrt{2 \cdot z}} \]
    8. Taylor expanded in t around 0

      \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \mathsf{fma}\left(t, \frac{1}{2} \cdot \color{blue}{t}, 1\right)\right) \cdot \sqrt{2 \cdot z} \]
    9. Step-by-step derivation
      1. Applied rewrites86.9%

        \[\leadsto \left(\left(x \cdot 0.5 - y\right) \cdot \mathsf{fma}\left(t, 0.5 \cdot \color{blue}{t}, 1\right)\right) \cdot \sqrt{2 \cdot z} \]

      if 5.0000000000000003e139 < (*.f64 t t) < 9.9999999999999994e253

      1. Initial program 99.4%

        \[\left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}} \]
      2. Add Preprocessing
      3. Taylor expanded in x around 0

        \[\leadsto \color{blue}{-1 \cdot \left(\left(y \cdot \left(e^{\frac{1}{2} \cdot {t}^{2}} \cdot \sqrt{2}\right)\right) \cdot \sqrt{z}\right)} \]
      4. Step-by-step derivation
        1. mul-1-negN/A

          \[\leadsto \color{blue}{\mathsf{neg}\left(\left(y \cdot \left(e^{\frac{1}{2} \cdot {t}^{2}} \cdot \sqrt{2}\right)\right) \cdot \sqrt{z}\right)} \]
        2. *-commutativeN/A

          \[\leadsto \mathsf{neg}\left(\color{blue}{\sqrt{z} \cdot \left(y \cdot \left(e^{\frac{1}{2} \cdot {t}^{2}} \cdot \sqrt{2}\right)\right)}\right) \]
        3. associate-*r*N/A

          \[\leadsto \mathsf{neg}\left(\sqrt{z} \cdot \color{blue}{\left(\left(y \cdot e^{\frac{1}{2} \cdot {t}^{2}}\right) \cdot \sqrt{2}\right)}\right) \]
        4. associate-*r*N/A

          \[\leadsto \mathsf{neg}\left(\color{blue}{\left(\sqrt{z} \cdot \left(y \cdot e^{\frac{1}{2} \cdot {t}^{2}}\right)\right) \cdot \sqrt{2}}\right) \]
        5. *-commutativeN/A

          \[\leadsto \mathsf{neg}\left(\color{blue}{\sqrt{2} \cdot \left(\sqrt{z} \cdot \left(y \cdot e^{\frac{1}{2} \cdot {t}^{2}}\right)\right)}\right) \]
        6. distribute-rgt-neg-inN/A

          \[\leadsto \color{blue}{\sqrt{2} \cdot \left(\mathsf{neg}\left(\sqrt{z} \cdot \left(y \cdot e^{\frac{1}{2} \cdot {t}^{2}}\right)\right)\right)} \]
        7. lower-*.f64N/A

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

          \[\leadsto \color{blue}{\sqrt{2}} \cdot \left(\mathsf{neg}\left(\sqrt{z} \cdot \left(y \cdot e^{\frac{1}{2} \cdot {t}^{2}}\right)\right)\right) \]
        9. distribute-rgt-neg-inN/A

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

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

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

          \[\leadsto \sqrt{2} \cdot \left(\color{blue}{\sqrt{z}} \cdot \left(-1 \cdot \left(y \cdot e^{\frac{1}{2} \cdot {t}^{2}}\right)\right)\right) \]
        13. mul-1-negN/A

          \[\leadsto \sqrt{2} \cdot \left(\sqrt{z} \cdot \color{blue}{\left(\mathsf{neg}\left(y \cdot e^{\frac{1}{2} \cdot {t}^{2}}\right)\right)}\right) \]
        14. *-commutativeN/A

          \[\leadsto \sqrt{2} \cdot \left(\sqrt{z} \cdot \left(\mathsf{neg}\left(\color{blue}{e^{\frac{1}{2} \cdot {t}^{2}} \cdot y}\right)\right)\right) \]
        15. distribute-rgt-neg-inN/A

          \[\leadsto \sqrt{2} \cdot \left(\sqrt{z} \cdot \color{blue}{\left(e^{\frac{1}{2} \cdot {t}^{2}} \cdot \left(\mathsf{neg}\left(y\right)\right)\right)}\right) \]
        16. mul-1-negN/A

          \[\leadsto \sqrt{2} \cdot \left(\sqrt{z} \cdot \left(e^{\frac{1}{2} \cdot {t}^{2}} \cdot \color{blue}{\left(-1 \cdot y\right)}\right)\right) \]
      5. Applied rewrites76.7%

        \[\leadsto \color{blue}{\sqrt{2} \cdot \left(\sqrt{z} \cdot \left(e^{0.5 \cdot \left(t \cdot t\right)} \cdot \left(-y\right)\right)\right)} \]
      6. Taylor expanded in t around 0

        \[\leadsto \sqrt{2} \cdot \left(\sqrt{z} \cdot \left(\left(1 + {t}^{2} \cdot \left(\frac{1}{2} + \frac{1}{8} \cdot {t}^{2}\right)\right) \cdot \left(\mathsf{neg}\left(\color{blue}{y}\right)\right)\right)\right) \]
      7. Step-by-step derivation
        1. Applied rewrites73.9%

          \[\leadsto \sqrt{2} \cdot \left(\sqrt{z} \cdot \left(\mathsf{fma}\left(t \cdot t, \mathsf{fma}\left(t, t \cdot 0.125, 0.5\right), 1\right) \cdot \left(-\color{blue}{y}\right)\right)\right) \]
        2. Step-by-step derivation
          1. Applied rewrites73.9%

            \[\leadsto \left(\left(-y\right) \cdot \mathsf{fma}\left(t \cdot t, \mathsf{fma}\left(t, t \cdot 0.125, 0.5\right), 1\right)\right) \cdot \color{blue}{\sqrt{2 \cdot z}} \]

          if 9.9999999999999994e253 < (*.f64 t t)

          1. Initial program 99.1%

            \[\left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}} \]
          2. Add Preprocessing
          3. Taylor expanded in t around 0

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

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

              \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \color{blue}{\mathsf{fma}\left({t}^{2}, \frac{1}{2} + \frac{1}{8} \cdot {t}^{2}, 1\right)} \]
            3. unpow2N/A

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

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

              \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(t \cdot t, \color{blue}{\frac{1}{8} \cdot {t}^{2} + \frac{1}{2}}, 1\right) \]
            6. unpow2N/A

              \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(t \cdot t, \frac{1}{8} \cdot \color{blue}{\left(t \cdot t\right)} + \frac{1}{2}, 1\right) \]
            7. associate-*r*N/A

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

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

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

              \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(t \cdot t, \mathsf{fma}\left(t, \color{blue}{t \cdot \frac{1}{8}}, \frac{1}{2}\right), 1\right) \]
            11. lower-*.f6499.1

              \[\leadsto \left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(t \cdot t, \mathsf{fma}\left(t, \color{blue}{t \cdot 0.125}, 0.5\right), 1\right) \]
          5. Applied rewrites99.1%

            \[\leadsto \left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \color{blue}{\mathsf{fma}\left(t \cdot t, \mathsf{fma}\left(t, t \cdot 0.125, 0.5\right), 1\right)} \]
          6. Step-by-step derivation
            1. lift-*.f64N/A

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

              \[\leadsto \color{blue}{\left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right)} \cdot \mathsf{fma}\left(t \cdot t, \mathsf{fma}\left(t, t \cdot \frac{1}{8}, \frac{1}{2}\right), 1\right) \]
            3. associate-*l*N/A

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

              \[\leadsto \left(x \cdot \frac{1}{2} - y\right) \cdot \color{blue}{\left(\mathsf{fma}\left(t \cdot t, \mathsf{fma}\left(t, t \cdot \frac{1}{8}, \frac{1}{2}\right), 1\right) \cdot \sqrt{z \cdot 2}\right)} \]
            5. associate-*r*N/A

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

              \[\leadsto \color{blue}{\left(\left(x \cdot \frac{1}{2} - y\right) \cdot \mathsf{fma}\left(t \cdot t, \mathsf{fma}\left(t, t \cdot \frac{1}{8}, \frac{1}{2}\right), 1\right)\right) \cdot \sqrt{z \cdot 2}} \]
          7. Applied rewrites100.0%

            \[\leadsto \color{blue}{\left(\left(x \cdot 0.5 - y\right) \cdot \mathsf{fma}\left(t, t \cdot \mathsf{fma}\left(t \cdot t, 0.125, 0.5\right), 1\right)\right) \cdot \sqrt{2 \cdot z}} \]
          8. Taylor expanded in t around 0

            \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \mathsf{fma}\left(t, \frac{1}{2} \cdot \color{blue}{t}, 1\right)\right) \cdot \sqrt{2 \cdot z} \]
          9. Step-by-step derivation
            1. Applied rewrites96.3%

              \[\leadsto \left(\left(x \cdot 0.5 - y\right) \cdot \mathsf{fma}\left(t, 0.5 \cdot \color{blue}{t}, 1\right)\right) \cdot \sqrt{2 \cdot z} \]
            2. Step-by-step derivation
              1. lift-*.f64N/A

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

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

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

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

                \[\leadsto \left(x \cdot \frac{1}{2} - y\right) \cdot \color{blue}{\left(\sqrt{2 \cdot z} \cdot \mathsf{fma}\left(t, \frac{1}{2} \cdot t, 1\right)\right)} \]
              6. lower-*.f6496.6

                \[\leadsto \left(x \cdot 0.5 - y\right) \cdot \color{blue}{\left(\sqrt{2 \cdot z} \cdot \mathsf{fma}\left(t, 0.5 \cdot t, 1\right)\right)} \]
            3. Applied rewrites96.6%

              \[\leadsto \color{blue}{\left(x \cdot 0.5 - y\right) \cdot \left(\sqrt{2 \cdot z} \cdot \mathsf{fma}\left(t, 0.5 \cdot t, 1\right)\right)} \]
          10. Recombined 3 regimes into one program.
          11. Final simplification88.6%

            \[\leadsto \begin{array}{l} \mathbf{if}\;t \cdot t \leq 5 \cdot 10^{+139}:\\ \;\;\;\;\sqrt{2 \cdot z} \cdot \left(\left(x \cdot 0.5 - y\right) \cdot \mathsf{fma}\left(t, 0.5 \cdot t, 1\right)\right)\\ \mathbf{elif}\;t \cdot t \leq 10^{+254}:\\ \;\;\;\;\left(y \cdot \mathsf{fma}\left(t \cdot t, \mathsf{fma}\left(t, t \cdot 0.125, 0.5\right), 1\right)\right) \cdot \left(-\sqrt{2 \cdot z}\right)\\ \mathbf{else}:\\ \;\;\;\;\left(x \cdot 0.5 - y\right) \cdot \left(\sqrt{2 \cdot z} \cdot \mathsf{fma}\left(t, 0.5 \cdot t, 1\right)\right)\\ \end{array} \]
          12. Add Preprocessing

          Developer Target 1: 99.4% accurate, 0.6× speedup?

          \[\begin{array}{l} \\ \left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot {\left(e^{1}\right)}^{\left(\frac{t \cdot t}{2}\right)} \end{array} \]
          (FPCore (x y z t)
           :precision binary64
           (* (* (- (* x 0.5) y) (sqrt (* z 2.0))) (pow (exp 1.0) (/ (* t t) 2.0))))
          double code(double x, double y, double z, double t) {
          	return (((x * 0.5) - y) * sqrt((z * 2.0))) * pow(exp(1.0), ((t * t) / 2.0));
          }
          
          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 * 0.5d0) - y) * sqrt((z * 2.0d0))) * (exp(1.0d0) ** ((t * t) / 2.0d0))
          end function
          
          public static double code(double x, double y, double z, double t) {
          	return (((x * 0.5) - y) * Math.sqrt((z * 2.0))) * Math.pow(Math.exp(1.0), ((t * t) / 2.0));
          }
          
          def code(x, y, z, t):
          	return (((x * 0.5) - y) * math.sqrt((z * 2.0))) * math.pow(math.exp(1.0), ((t * t) / 2.0))
          
          function code(x, y, z, t)
          	return Float64(Float64(Float64(Float64(x * 0.5) - y) * sqrt(Float64(z * 2.0))) * (exp(1.0) ^ Float64(Float64(t * t) / 2.0)))
          end
          
          function tmp = code(x, y, z, t)
          	tmp = (((x * 0.5) - y) * sqrt((z * 2.0))) * (exp(1.0) ^ ((t * t) / 2.0));
          end
          
          code[x_, y_, z_, t_] := N[(N[(N[(N[(x * 0.5), $MachinePrecision] - y), $MachinePrecision] * N[Sqrt[N[(z * 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[Power[N[Exp[1.0], $MachinePrecision], N[(N[(t * t), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot {\left(e^{1}\right)}^{\left(\frac{t \cdot t}{2}\right)}
          \end{array}
          

          Reproduce

          ?
          herbie shell --seed 2024228 
          (FPCore (x y z t)
            :name "Data.Number.Erf:$cinvnormcdf from erf-2.0.0.0, A"
            :precision binary64
          
            :alt
            (! :herbie-platform default (* (* (- (* x 1/2) y) (sqrt (* z 2))) (pow (exp 1) (/ (* t t) 2))))
          
            (* (* (- (* x 0.5) y) (sqrt (* z 2.0))) (exp (/ (* t t) 2.0))))