Jmat.Real.erf

Percentage Accurate: 79.1% → 86.5%
Time: 12.7s
Alternatives: 12
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1}{1 + 0.3275911 \cdot \left|x\right|}\\ 1 - \left(t\_0 \cdot \left(0.254829592 + t\_0 \cdot \left(-0.284496736 + t\_0 \cdot \left(1.421413741 + t\_0 \cdot \left(-1.453152027 + t\_0 \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|} \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))))
   (-
    1.0
    (*
     (*
      t_0
      (+
       0.254829592
       (*
        t_0
        (+
         -0.284496736
         (*
          t_0
          (+ 1.421413741 (* t_0 (+ -1.453152027 (* t_0 1.061405429)))))))))
     (exp (- (* (fabs x) (fabs x))))))))
double code(double x) {
	double t_0 = 1.0 / (1.0 + (0.3275911 * fabs(x)));
	return 1.0 - ((t_0 * (0.254829592 + (t_0 * (-0.284496736 + (t_0 * (1.421413741 + (t_0 * (-1.453152027 + (t_0 * 1.061405429))))))))) * exp(-(fabs(x) * fabs(x))));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8) :: t_0
    t_0 = 1.0d0 / (1.0d0 + (0.3275911d0 * abs(x)))
    code = 1.0d0 - ((t_0 * (0.254829592d0 + (t_0 * ((-0.284496736d0) + (t_0 * (1.421413741d0 + (t_0 * ((-1.453152027d0) + (t_0 * 1.061405429d0))))))))) * exp(-(abs(x) * abs(x))))
end function
public static double code(double x) {
	double t_0 = 1.0 / (1.0 + (0.3275911 * Math.abs(x)));
	return 1.0 - ((t_0 * (0.254829592 + (t_0 * (-0.284496736 + (t_0 * (1.421413741 + (t_0 * (-1.453152027 + (t_0 * 1.061405429))))))))) * Math.exp(-(Math.abs(x) * Math.abs(x))));
}
def code(x):
	t_0 = 1.0 / (1.0 + (0.3275911 * math.fabs(x)))
	return 1.0 - ((t_0 * (0.254829592 + (t_0 * (-0.284496736 + (t_0 * (1.421413741 + (t_0 * (-1.453152027 + (t_0 * 1.061405429))))))))) * math.exp(-(math.fabs(x) * math.fabs(x))))
function code(x)
	t_0 = Float64(1.0 / Float64(1.0 + Float64(0.3275911 * abs(x))))
	return Float64(1.0 - Float64(Float64(t_0 * Float64(0.254829592 + Float64(t_0 * Float64(-0.284496736 + Float64(t_0 * Float64(1.421413741 + Float64(t_0 * Float64(-1.453152027 + Float64(t_0 * 1.061405429))))))))) * exp(Float64(-Float64(abs(x) * abs(x))))))
end
function tmp = code(x)
	t_0 = 1.0 / (1.0 + (0.3275911 * abs(x)));
	tmp = 1.0 - ((t_0 * (0.254829592 + (t_0 * (-0.284496736 + (t_0 * (1.421413741 + (t_0 * (-1.453152027 + (t_0 * 1.061405429))))))))) * exp(-(abs(x) * abs(x))));
end
code[x_] := Block[{t$95$0 = N[(1.0 / N[(1.0 + N[(0.3275911 * N[Abs[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(1.0 - N[(N[(t$95$0 * N[(0.254829592 + N[(t$95$0 * N[(-0.284496736 + N[(t$95$0 * N[(1.421413741 + N[(t$95$0 * N[(-1.453152027 + N[(t$95$0 * 1.061405429), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Exp[(-N[(N[Abs[x], $MachinePrecision] * N[Abs[x], $MachinePrecision]), $MachinePrecision])], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{1}{1 + 0.3275911 \cdot \left|x\right|}\\
1 - \left(t\_0 \cdot \left(0.254829592 + t\_0 \cdot \left(-0.284496736 + t\_0 \cdot \left(1.421413741 + t\_0 \cdot \left(-1.453152027 + t\_0 \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}
\end{array}
\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: 79.1% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1}{1 + 0.3275911 \cdot \left|x\right|}\\ 1 - \left(t\_0 \cdot \left(0.254829592 + t\_0 \cdot \left(-0.284496736 + t\_0 \cdot \left(1.421413741 + t\_0 \cdot \left(-1.453152027 + t\_0 \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|} \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))))
   (-
    1.0
    (*
     (*
      t_0
      (+
       0.254829592
       (*
        t_0
        (+
         -0.284496736
         (*
          t_0
          (+ 1.421413741 (* t_0 (+ -1.453152027 (* t_0 1.061405429)))))))))
     (exp (- (* (fabs x) (fabs x))))))))
double code(double x) {
	double t_0 = 1.0 / (1.0 + (0.3275911 * fabs(x)));
	return 1.0 - ((t_0 * (0.254829592 + (t_0 * (-0.284496736 + (t_0 * (1.421413741 + (t_0 * (-1.453152027 + (t_0 * 1.061405429))))))))) * exp(-(fabs(x) * fabs(x))));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8) :: t_0
    t_0 = 1.0d0 / (1.0d0 + (0.3275911d0 * abs(x)))
    code = 1.0d0 - ((t_0 * (0.254829592d0 + (t_0 * ((-0.284496736d0) + (t_0 * (1.421413741d0 + (t_0 * ((-1.453152027d0) + (t_0 * 1.061405429d0))))))))) * exp(-(abs(x) * abs(x))))
end function
public static double code(double x) {
	double t_0 = 1.0 / (1.0 + (0.3275911 * Math.abs(x)));
	return 1.0 - ((t_0 * (0.254829592 + (t_0 * (-0.284496736 + (t_0 * (1.421413741 + (t_0 * (-1.453152027 + (t_0 * 1.061405429))))))))) * Math.exp(-(Math.abs(x) * Math.abs(x))));
}
def code(x):
	t_0 = 1.0 / (1.0 + (0.3275911 * math.fabs(x)))
	return 1.0 - ((t_0 * (0.254829592 + (t_0 * (-0.284496736 + (t_0 * (1.421413741 + (t_0 * (-1.453152027 + (t_0 * 1.061405429))))))))) * math.exp(-(math.fabs(x) * math.fabs(x))))
function code(x)
	t_0 = Float64(1.0 / Float64(1.0 + Float64(0.3275911 * abs(x))))
	return Float64(1.0 - Float64(Float64(t_0 * Float64(0.254829592 + Float64(t_0 * Float64(-0.284496736 + Float64(t_0 * Float64(1.421413741 + Float64(t_0 * Float64(-1.453152027 + Float64(t_0 * 1.061405429))))))))) * exp(Float64(-Float64(abs(x) * abs(x))))))
end
function tmp = code(x)
	t_0 = 1.0 / (1.0 + (0.3275911 * abs(x)));
	tmp = 1.0 - ((t_0 * (0.254829592 + (t_0 * (-0.284496736 + (t_0 * (1.421413741 + (t_0 * (-1.453152027 + (t_0 * 1.061405429))))))))) * exp(-(abs(x) * abs(x))));
end
code[x_] := Block[{t$95$0 = N[(1.0 / N[(1.0 + N[(0.3275911 * N[Abs[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(1.0 - N[(N[(t$95$0 * N[(0.254829592 + N[(t$95$0 * N[(-0.284496736 + N[(t$95$0 * N[(1.421413741 + N[(t$95$0 * N[(-1.453152027 + N[(t$95$0 * 1.061405429), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Exp[(-N[(N[Abs[x], $MachinePrecision] * N[Abs[x], $MachinePrecision]), $MachinePrecision])], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{1}{1 + 0.3275911 \cdot \left|x\right|}\\
1 - \left(t\_0 \cdot \left(0.254829592 + t\_0 \cdot \left(-0.284496736 + t\_0 \cdot \left(1.421413741 + t\_0 \cdot \left(-1.453152027 + t\_0 \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}
\end{array}
\end{array}

Alternative 1: 86.5% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left|x\right| \cdot 0.3275911 - -1\\ t_1 := \frac{\frac{\frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0} + -0.284496736}{t\_0} + 0.254829592}{t\_0 \cdot {\left(e^{x}\right)}^{x}}\\ t_2 := 1 + {t\_1}^{2}\\ \frac{\frac{1}{t\_2} - \frac{{t\_1}^{4}}{t\_2}}{t\_1 - -1} \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (- (* (fabs x) 0.3275911) -1.0))
        (t_1
         (/
          (+
           (/
            (+
             (/
              (- (/ (- (/ 1.061405429 t_0) 1.453152027) t_0) -1.421413741)
              t_0)
             -0.284496736)
            t_0)
           0.254829592)
          (* t_0 (pow (exp x) x))))
        (t_2 (+ 1.0 (pow t_1 2.0))))
   (/ (- (/ 1.0 t_2) (/ (pow t_1 4.0) t_2)) (- t_1 -1.0))))
double code(double x) {
	double t_0 = (fabs(x) * 0.3275911) - -1.0;
	double t_1 = ((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / (t_0 * pow(exp(x), x));
	double t_2 = 1.0 + pow(t_1, 2.0);
	return ((1.0 / t_2) - (pow(t_1, 4.0) / t_2)) / (t_1 - -1.0);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: t_2
    t_0 = (abs(x) * 0.3275911d0) - (-1.0d0)
    t_1 = ((((((((1.061405429d0 / t_0) - 1.453152027d0) / t_0) - (-1.421413741d0)) / t_0) + (-0.284496736d0)) / t_0) + 0.254829592d0) / (t_0 * (exp(x) ** x))
    t_2 = 1.0d0 + (t_1 ** 2.0d0)
    code = ((1.0d0 / t_2) - ((t_1 ** 4.0d0) / t_2)) / (t_1 - (-1.0d0))
end function
public static double code(double x) {
	double t_0 = (Math.abs(x) * 0.3275911) - -1.0;
	double t_1 = ((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / (t_0 * Math.pow(Math.exp(x), x));
	double t_2 = 1.0 + Math.pow(t_1, 2.0);
	return ((1.0 / t_2) - (Math.pow(t_1, 4.0) / t_2)) / (t_1 - -1.0);
}
def code(x):
	t_0 = (math.fabs(x) * 0.3275911) - -1.0
	t_1 = ((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / (t_0 * math.pow(math.exp(x), x))
	t_2 = 1.0 + math.pow(t_1, 2.0)
	return ((1.0 / t_2) - (math.pow(t_1, 4.0) / t_2)) / (t_1 - -1.0)
function code(x)
	t_0 = Float64(Float64(abs(x) * 0.3275911) - -1.0)
	t_1 = Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / Float64(t_0 * (exp(x) ^ x)))
	t_2 = Float64(1.0 + (t_1 ^ 2.0))
	return Float64(Float64(Float64(1.0 / t_2) - Float64((t_1 ^ 4.0) / t_2)) / Float64(t_1 - -1.0))
end
function tmp = code(x)
	t_0 = (abs(x) * 0.3275911) - -1.0;
	t_1 = ((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / (t_0 * (exp(x) ^ x));
	t_2 = 1.0 + (t_1 ^ 2.0);
	tmp = ((1.0 / t_2) - ((t_1 ^ 4.0) / t_2)) / (t_1 - -1.0);
end
code[x_] := Block[{t$95$0 = N[(N[(N[Abs[x], $MachinePrecision] * 0.3275911), $MachinePrecision] - -1.0), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(N[(N[(N[(N[(N[(N[(1.061405429 / t$95$0), $MachinePrecision] - 1.453152027), $MachinePrecision] / t$95$0), $MachinePrecision] - -1.421413741), $MachinePrecision] / t$95$0), $MachinePrecision] + -0.284496736), $MachinePrecision] / t$95$0), $MachinePrecision] + 0.254829592), $MachinePrecision] / N[(t$95$0 * N[Power[N[Exp[x], $MachinePrecision], x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(1.0 + N[Power[t$95$1, 2.0], $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(1.0 / t$95$2), $MachinePrecision] - N[(N[Power[t$95$1, 4.0], $MachinePrecision] / t$95$2), $MachinePrecision]), $MachinePrecision] / N[(t$95$1 - -1.0), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left|x\right| \cdot 0.3275911 - -1\\
t_1 := \frac{\frac{\frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0} + -0.284496736}{t\_0} + 0.254829592}{t\_0 \cdot {\left(e^{x}\right)}^{x}}\\
t_2 := 1 + {t\_1}^{2}\\
\frac{\frac{1}{t\_2} - \frac{{t\_1}^{4}}{t\_2}}{t\_1 - -1}
\end{array}
\end{array}
Derivation
  1. Initial program 80.1%

    \[1 - \left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-0.284496736 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(1.421413741 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-1.453152027 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|} \]
  2. Add Preprocessing
  3. Applied rewrites80.1%

    \[\leadsto \color{blue}{\frac{1 - {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}{\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}} + 1}} \]
  4. Applied rewrites80.2%

    \[\leadsto \frac{\color{blue}{\frac{1 - {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2} \cdot {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}{1 + {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}}}{\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}} + 1} \]
  5. Applied rewrites87.2%

    \[\leadsto \frac{\color{blue}{\frac{1}{1 + {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}} - \frac{{\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{4}}{1 + {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}}}{\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}} + 1} \]
  6. Final simplification87.2%

    \[\leadsto \frac{\frac{1}{1 + {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}} - \frac{{\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{4}}{1 + {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}}{\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}} - -1} \]
  7. Add Preprocessing

Alternative 2: 79.2% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left|x\right| \cdot 0.3275911 - -1\\ t_1 := \frac{\frac{\frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0} + -0.284496736}{t\_0} + 0.254829592}{t\_0 \cdot {\left(e^{x}\right)}^{x}}\\ t_2 := {t\_1}^{2}\\ \frac{\frac{1 - t\_2 \cdot t\_2}{1 + t\_2}}{t\_1 - -1} \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (- (* (fabs x) 0.3275911) -1.0))
        (t_1
         (/
          (+
           (/
            (+
             (/
              (- (/ (- (/ 1.061405429 t_0) 1.453152027) t_0) -1.421413741)
              t_0)
             -0.284496736)
            t_0)
           0.254829592)
          (* t_0 (pow (exp x) x))))
        (t_2 (pow t_1 2.0)))
   (/ (/ (- 1.0 (* t_2 t_2)) (+ 1.0 t_2)) (- t_1 -1.0))))
double code(double x) {
	double t_0 = (fabs(x) * 0.3275911) - -1.0;
	double t_1 = ((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / (t_0 * pow(exp(x), x));
	double t_2 = pow(t_1, 2.0);
	return ((1.0 - (t_2 * t_2)) / (1.0 + t_2)) / (t_1 - -1.0);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: t_2
    t_0 = (abs(x) * 0.3275911d0) - (-1.0d0)
    t_1 = ((((((((1.061405429d0 / t_0) - 1.453152027d0) / t_0) - (-1.421413741d0)) / t_0) + (-0.284496736d0)) / t_0) + 0.254829592d0) / (t_0 * (exp(x) ** x))
    t_2 = t_1 ** 2.0d0
    code = ((1.0d0 - (t_2 * t_2)) / (1.0d0 + t_2)) / (t_1 - (-1.0d0))
end function
public static double code(double x) {
	double t_0 = (Math.abs(x) * 0.3275911) - -1.0;
	double t_1 = ((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / (t_0 * Math.pow(Math.exp(x), x));
	double t_2 = Math.pow(t_1, 2.0);
	return ((1.0 - (t_2 * t_2)) / (1.0 + t_2)) / (t_1 - -1.0);
}
def code(x):
	t_0 = (math.fabs(x) * 0.3275911) - -1.0
	t_1 = ((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / (t_0 * math.pow(math.exp(x), x))
	t_2 = math.pow(t_1, 2.0)
	return ((1.0 - (t_2 * t_2)) / (1.0 + t_2)) / (t_1 - -1.0)
function code(x)
	t_0 = Float64(Float64(abs(x) * 0.3275911) - -1.0)
	t_1 = Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / Float64(t_0 * (exp(x) ^ x)))
	t_2 = t_1 ^ 2.0
	return Float64(Float64(Float64(1.0 - Float64(t_2 * t_2)) / Float64(1.0 + t_2)) / Float64(t_1 - -1.0))
end
function tmp = code(x)
	t_0 = (abs(x) * 0.3275911) - -1.0;
	t_1 = ((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / (t_0 * (exp(x) ^ x));
	t_2 = t_1 ^ 2.0;
	tmp = ((1.0 - (t_2 * t_2)) / (1.0 + t_2)) / (t_1 - -1.0);
end
code[x_] := Block[{t$95$0 = N[(N[(N[Abs[x], $MachinePrecision] * 0.3275911), $MachinePrecision] - -1.0), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(N[(N[(N[(N[(N[(N[(1.061405429 / t$95$0), $MachinePrecision] - 1.453152027), $MachinePrecision] / t$95$0), $MachinePrecision] - -1.421413741), $MachinePrecision] / t$95$0), $MachinePrecision] + -0.284496736), $MachinePrecision] / t$95$0), $MachinePrecision] + 0.254829592), $MachinePrecision] / N[(t$95$0 * N[Power[N[Exp[x], $MachinePrecision], x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[Power[t$95$1, 2.0], $MachinePrecision]}, N[(N[(N[(1.0 - N[(t$95$2 * t$95$2), $MachinePrecision]), $MachinePrecision] / N[(1.0 + t$95$2), $MachinePrecision]), $MachinePrecision] / N[(t$95$1 - -1.0), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left|x\right| \cdot 0.3275911 - -1\\
t_1 := \frac{\frac{\frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0} + -0.284496736}{t\_0} + 0.254829592}{t\_0 \cdot {\left(e^{x}\right)}^{x}}\\
t_2 := {t\_1}^{2}\\
\frac{\frac{1 - t\_2 \cdot t\_2}{1 + t\_2}}{t\_1 - -1}
\end{array}
\end{array}
Derivation
  1. Initial program 80.1%

    \[1 - \left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-0.284496736 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(1.421413741 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-1.453152027 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|} \]
  2. Add Preprocessing
  3. Applied rewrites80.1%

    \[\leadsto \color{blue}{\frac{1 - {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}{\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}} + 1}} \]
  4. Applied rewrites80.2%

    \[\leadsto \frac{\color{blue}{\frac{1 - {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2} \cdot {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}{1 + {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}}}{\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}} + 1} \]
  5. Final simplification80.2%

    \[\leadsto \frac{\frac{1 - {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2} \cdot {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}{1 + {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}}{\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}} - -1} \]
  6. Add Preprocessing

Alternative 3: 79.2% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left|x\right| \cdot 0.3275911 - -1\\ t_1 := -0.3275911 \cdot \left|x\right|\\ t_2 := \frac{\frac{\frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0} + -0.284496736}{t\_0} + 0.254829592}{t\_1 - 1} \cdot e^{\left(-x\right) \cdot x}\\ t_3 := 1 - t\_1\\ \frac{1 + {t\_2}^{3}}{1 + \left({\left(\frac{\frac{\left(\frac{1.421413741}{t\_3} + {t\_3}^{-3} \cdot 1.061405429\right) - \left({t\_3}^{-2} \cdot 1.453152027 + 0.284496736\right)}{t\_0} + 0.254829592}{t\_0 \cdot {\left(e^{x}\right)}^{x}}\right)}^{2} - t\_2\right)} \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (- (* (fabs x) 0.3275911) -1.0))
        (t_1 (* -0.3275911 (fabs x)))
        (t_2
         (*
          (/
           (+
            (/
             (+
              (/
               (- (/ (- (/ 1.061405429 t_0) 1.453152027) t_0) -1.421413741)
               t_0)
              -0.284496736)
             t_0)
            0.254829592)
           (- t_1 1.0))
          (exp (* (- x) x))))
        (t_3 (- 1.0 t_1)))
   (/
    (+ 1.0 (pow t_2 3.0))
    (+
     1.0
     (-
      (pow
       (/
        (+
         (/
          (-
           (+ (/ 1.421413741 t_3) (* (pow t_3 -3.0) 1.061405429))
           (+ (* (pow t_3 -2.0) 1.453152027) 0.284496736))
          t_0)
         0.254829592)
        (* t_0 (pow (exp x) x)))
       2.0)
      t_2)))))
double code(double x) {
	double t_0 = (fabs(x) * 0.3275911) - -1.0;
	double t_1 = -0.3275911 * fabs(x);
	double t_2 = (((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / (t_1 - 1.0)) * exp((-x * x));
	double t_3 = 1.0 - t_1;
	return (1.0 + pow(t_2, 3.0)) / (1.0 + (pow(((((((1.421413741 / t_3) + (pow(t_3, -3.0) * 1.061405429)) - ((pow(t_3, -2.0) * 1.453152027) + 0.284496736)) / t_0) + 0.254829592) / (t_0 * pow(exp(x), x))), 2.0) - t_2));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: t_2
    real(8) :: t_3
    t_0 = (abs(x) * 0.3275911d0) - (-1.0d0)
    t_1 = (-0.3275911d0) * abs(x)
    t_2 = (((((((((1.061405429d0 / t_0) - 1.453152027d0) / t_0) - (-1.421413741d0)) / t_0) + (-0.284496736d0)) / t_0) + 0.254829592d0) / (t_1 - 1.0d0)) * exp((-x * x))
    t_3 = 1.0d0 - t_1
    code = (1.0d0 + (t_2 ** 3.0d0)) / (1.0d0 + ((((((((1.421413741d0 / t_3) + ((t_3 ** (-3.0d0)) * 1.061405429d0)) - (((t_3 ** (-2.0d0)) * 1.453152027d0) + 0.284496736d0)) / t_0) + 0.254829592d0) / (t_0 * (exp(x) ** x))) ** 2.0d0) - t_2))
end function
public static double code(double x) {
	double t_0 = (Math.abs(x) * 0.3275911) - -1.0;
	double t_1 = -0.3275911 * Math.abs(x);
	double t_2 = (((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / (t_1 - 1.0)) * Math.exp((-x * x));
	double t_3 = 1.0 - t_1;
	return (1.0 + Math.pow(t_2, 3.0)) / (1.0 + (Math.pow(((((((1.421413741 / t_3) + (Math.pow(t_3, -3.0) * 1.061405429)) - ((Math.pow(t_3, -2.0) * 1.453152027) + 0.284496736)) / t_0) + 0.254829592) / (t_0 * Math.pow(Math.exp(x), x))), 2.0) - t_2));
}
def code(x):
	t_0 = (math.fabs(x) * 0.3275911) - -1.0
	t_1 = -0.3275911 * math.fabs(x)
	t_2 = (((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / (t_1 - 1.0)) * math.exp((-x * x))
	t_3 = 1.0 - t_1
	return (1.0 + math.pow(t_2, 3.0)) / (1.0 + (math.pow(((((((1.421413741 / t_3) + (math.pow(t_3, -3.0) * 1.061405429)) - ((math.pow(t_3, -2.0) * 1.453152027) + 0.284496736)) / t_0) + 0.254829592) / (t_0 * math.pow(math.exp(x), x))), 2.0) - t_2))
function code(x)
	t_0 = Float64(Float64(abs(x) * 0.3275911) - -1.0)
	t_1 = Float64(-0.3275911 * abs(x))
	t_2 = Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / Float64(t_1 - 1.0)) * exp(Float64(Float64(-x) * x)))
	t_3 = Float64(1.0 - t_1)
	return Float64(Float64(1.0 + (t_2 ^ 3.0)) / Float64(1.0 + Float64((Float64(Float64(Float64(Float64(Float64(Float64(1.421413741 / t_3) + Float64((t_3 ^ -3.0) * 1.061405429)) - Float64(Float64((t_3 ^ -2.0) * 1.453152027) + 0.284496736)) / t_0) + 0.254829592) / Float64(t_0 * (exp(x) ^ x))) ^ 2.0) - t_2)))
end
function tmp = code(x)
	t_0 = (abs(x) * 0.3275911) - -1.0;
	t_1 = -0.3275911 * abs(x);
	t_2 = (((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / (t_1 - 1.0)) * exp((-x * x));
	t_3 = 1.0 - t_1;
	tmp = (1.0 + (t_2 ^ 3.0)) / (1.0 + ((((((((1.421413741 / t_3) + ((t_3 ^ -3.0) * 1.061405429)) - (((t_3 ^ -2.0) * 1.453152027) + 0.284496736)) / t_0) + 0.254829592) / (t_0 * (exp(x) ^ x))) ^ 2.0) - t_2));
end
code[x_] := Block[{t$95$0 = N[(N[(N[Abs[x], $MachinePrecision] * 0.3275911), $MachinePrecision] - -1.0), $MachinePrecision]}, Block[{t$95$1 = N[(-0.3275911 * N[Abs[x], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(N[(N[(N[(N[(N[(N[(N[(1.061405429 / t$95$0), $MachinePrecision] - 1.453152027), $MachinePrecision] / t$95$0), $MachinePrecision] - -1.421413741), $MachinePrecision] / t$95$0), $MachinePrecision] + -0.284496736), $MachinePrecision] / t$95$0), $MachinePrecision] + 0.254829592), $MachinePrecision] / N[(t$95$1 - 1.0), $MachinePrecision]), $MachinePrecision] * N[Exp[N[((-x) * x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(1.0 - t$95$1), $MachinePrecision]}, N[(N[(1.0 + N[Power[t$95$2, 3.0], $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[(N[Power[N[(N[(N[(N[(N[(N[(1.421413741 / t$95$3), $MachinePrecision] + N[(N[Power[t$95$3, -3.0], $MachinePrecision] * 1.061405429), $MachinePrecision]), $MachinePrecision] - N[(N[(N[Power[t$95$3, -2.0], $MachinePrecision] * 1.453152027), $MachinePrecision] + 0.284496736), $MachinePrecision]), $MachinePrecision] / t$95$0), $MachinePrecision] + 0.254829592), $MachinePrecision] / N[(t$95$0 * N[Power[N[Exp[x], $MachinePrecision], x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision] - t$95$2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left|x\right| \cdot 0.3275911 - -1\\
t_1 := -0.3275911 \cdot \left|x\right|\\
t_2 := \frac{\frac{\frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0} + -0.284496736}{t\_0} + 0.254829592}{t\_1 - 1} \cdot e^{\left(-x\right) \cdot x}\\
t_3 := 1 - t\_1\\
\frac{1 + {t\_2}^{3}}{1 + \left({\left(\frac{\frac{\left(\frac{1.421413741}{t\_3} + {t\_3}^{-3} \cdot 1.061405429\right) - \left({t\_3}^{-2} \cdot 1.453152027 + 0.284496736\right)}{t\_0} + 0.254829592}{t\_0 \cdot {\left(e^{x}\right)}^{x}}\right)}^{2} - t\_2\right)}
\end{array}
\end{array}
Derivation
  1. Initial program 80.1%

    \[1 - \left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-0.284496736 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(1.421413741 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-1.453152027 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|} \]
  2. Add Preprocessing
  3. Applied rewrites80.2%

    \[\leadsto \color{blue}{\frac{1 + {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{-0.3275911 \cdot \left|x\right| + -1} \cdot e^{\left(-x\right) \cdot x}\right)}^{3}}{1 + \left({\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2} - 1 \cdot \left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{-0.3275911 \cdot \left|x\right| + -1} \cdot e^{\left(-x\right) \cdot x}\right)\right)}} \]
  4. Taylor expanded in x around 0

    \[\leadsto \frac{1 + {\left(\frac{\frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{31853699}{125000000}}{\frac{-3275911}{10000000} \cdot \left|x\right| + -1} \cdot e^{\left(-x\right) \cdot x}\right)}^{3}}{1 + \left({\left(\frac{\frac{\color{blue}{\left(\frac{1061405429}{1000000000} \cdot \frac{1}{{\left(1 + \frac{3275911}{10000000} \cdot \left|x\right|\right)}^{3}} + \frac{1421413741}{1000000000} \cdot \frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|}\right) - \left(\frac{8890523}{31250000} + \frac{1453152027}{1000000000} \cdot \frac{1}{{\left(1 + \frac{3275911}{10000000} \cdot \left|x\right|\right)}^{2}}\right)}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{31853699}{125000000}}{\left(\left|x\right| \cdot \frac{3275911}{10000000} - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2} - 1 \cdot \left(\frac{\frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{31853699}{125000000}}{\frac{-3275911}{10000000} \cdot \left|x\right| + -1} \cdot e^{\left(-x\right) \cdot x}\right)\right)} \]
  5. Step-by-step derivation
    1. lower--.f64N/A

      \[\leadsto \frac{1 + {\left(\frac{\frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{31853699}{125000000}}{\frac{-3275911}{10000000} \cdot \left|x\right| + -1} \cdot e^{\left(-x\right) \cdot x}\right)}^{3}}{1 + \left({\left(\frac{\frac{\left(\frac{1061405429}{1000000000} \cdot \frac{1}{{\left(1 + \frac{3275911}{10000000} \cdot \left|x\right|\right)}^{3}} + \frac{1421413741}{1000000000} \cdot \frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|}\right) - \color{blue}{\left(\frac{8890523}{31250000} + \frac{1453152027}{1000000000} \cdot \frac{1}{{\left(1 + \frac{3275911}{10000000} \cdot \left|x\right|\right)}^{2}}\right)}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{31853699}{125000000}}{\left(\left|x\right| \cdot \frac{3275911}{10000000} - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2} - 1 \cdot \left(\frac{\frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{31853699}{125000000}}{\frac{-3275911}{10000000} \cdot \left|x\right| + -1} \cdot e^{\left(-x\right) \cdot x}\right)\right)} \]
  6. Applied rewrites80.2%

    \[\leadsto \frac{1 + {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{-0.3275911 \cdot \left|x\right| + -1} \cdot e^{\left(-x\right) \cdot x}\right)}^{3}}{1 + \left({\left(\frac{\frac{\color{blue}{\left(\frac{1.421413741}{1 - -0.3275911 \cdot \left|x\right|} + {\left(1 - -0.3275911 \cdot \left|x\right|\right)}^{-3} \cdot 1.061405429\right) - \left({\left(1 - -0.3275911 \cdot \left|x\right|\right)}^{-2} \cdot 1.453152027 + 0.284496736\right)}}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2} - 1 \cdot \left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{-0.3275911 \cdot \left|x\right| + -1} \cdot e^{\left(-x\right) \cdot x}\right)\right)} \]
  7. Final simplification80.2%

    \[\leadsto \frac{1 + {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{-0.3275911 \cdot \left|x\right| - 1} \cdot e^{\left(-x\right) \cdot x}\right)}^{3}}{1 + \left({\left(\frac{\frac{\left(\frac{1.421413741}{1 - -0.3275911 \cdot \left|x\right|} + {\left(1 - -0.3275911 \cdot \left|x\right|\right)}^{-3} \cdot 1.061405429\right) - \left({\left(1 - -0.3275911 \cdot \left|x\right|\right)}^{-2} \cdot 1.453152027 + 0.284496736\right)}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2} - \frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{-0.3275911 \cdot \left|x\right| - 1} \cdot e^{\left(-x\right) \cdot x}\right)} \]
  8. Add Preprocessing

Alternative 4: 79.2% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left|x\right| \cdot 0.3275911 - -1\\ t_1 := \frac{\frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0} + -0.284496736}{t\_0} + 0.254829592\\ t_2 := \frac{t\_1}{-0.3275911 \cdot \left|x\right| - 1} \cdot e^{\left(-x\right) \cdot x}\\ \frac{1 + {t\_2}^{3}}{1 + \left({\left(\frac{t\_1}{t\_0 \cdot {\left(e^{x}\right)}^{x}}\right)}^{2} - t\_2\right)} \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (- (* (fabs x) 0.3275911) -1.0))
        (t_1
         (+
          (/
           (+
            (/
             (- (/ (- (/ 1.061405429 t_0) 1.453152027) t_0) -1.421413741)
             t_0)
            -0.284496736)
           t_0)
          0.254829592))
        (t_2 (* (/ t_1 (- (* -0.3275911 (fabs x)) 1.0)) (exp (* (- x) x)))))
   (/
    (+ 1.0 (pow t_2 3.0))
    (+ 1.0 (- (pow (/ t_1 (* t_0 (pow (exp x) x))) 2.0) t_2)))))
double code(double x) {
	double t_0 = (fabs(x) * 0.3275911) - -1.0;
	double t_1 = (((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592;
	double t_2 = (t_1 / ((-0.3275911 * fabs(x)) - 1.0)) * exp((-x * x));
	return (1.0 + pow(t_2, 3.0)) / (1.0 + (pow((t_1 / (t_0 * pow(exp(x), x))), 2.0) - t_2));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: t_2
    t_0 = (abs(x) * 0.3275911d0) - (-1.0d0)
    t_1 = (((((((1.061405429d0 / t_0) - 1.453152027d0) / t_0) - (-1.421413741d0)) / t_0) + (-0.284496736d0)) / t_0) + 0.254829592d0
    t_2 = (t_1 / (((-0.3275911d0) * abs(x)) - 1.0d0)) * exp((-x * x))
    code = (1.0d0 + (t_2 ** 3.0d0)) / (1.0d0 + (((t_1 / (t_0 * (exp(x) ** x))) ** 2.0d0) - t_2))
end function
public static double code(double x) {
	double t_0 = (Math.abs(x) * 0.3275911) - -1.0;
	double t_1 = (((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592;
	double t_2 = (t_1 / ((-0.3275911 * Math.abs(x)) - 1.0)) * Math.exp((-x * x));
	return (1.0 + Math.pow(t_2, 3.0)) / (1.0 + (Math.pow((t_1 / (t_0 * Math.pow(Math.exp(x), x))), 2.0) - t_2));
}
def code(x):
	t_0 = (math.fabs(x) * 0.3275911) - -1.0
	t_1 = (((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592
	t_2 = (t_1 / ((-0.3275911 * math.fabs(x)) - 1.0)) * math.exp((-x * x))
	return (1.0 + math.pow(t_2, 3.0)) / (1.0 + (math.pow((t_1 / (t_0 * math.pow(math.exp(x), x))), 2.0) - t_2))
function code(x)
	t_0 = Float64(Float64(abs(x) * 0.3275911) - -1.0)
	t_1 = Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592)
	t_2 = Float64(Float64(t_1 / Float64(Float64(-0.3275911 * abs(x)) - 1.0)) * exp(Float64(Float64(-x) * x)))
	return Float64(Float64(1.0 + (t_2 ^ 3.0)) / Float64(1.0 + Float64((Float64(t_1 / Float64(t_0 * (exp(x) ^ x))) ^ 2.0) - t_2)))
end
function tmp = code(x)
	t_0 = (abs(x) * 0.3275911) - -1.0;
	t_1 = (((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592;
	t_2 = (t_1 / ((-0.3275911 * abs(x)) - 1.0)) * exp((-x * x));
	tmp = (1.0 + (t_2 ^ 3.0)) / (1.0 + (((t_1 / (t_0 * (exp(x) ^ x))) ^ 2.0) - t_2));
end
code[x_] := Block[{t$95$0 = N[(N[(N[Abs[x], $MachinePrecision] * 0.3275911), $MachinePrecision] - -1.0), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(N[(N[(N[(N[(N[(1.061405429 / t$95$0), $MachinePrecision] - 1.453152027), $MachinePrecision] / t$95$0), $MachinePrecision] - -1.421413741), $MachinePrecision] / t$95$0), $MachinePrecision] + -0.284496736), $MachinePrecision] / t$95$0), $MachinePrecision] + 0.254829592), $MachinePrecision]}, Block[{t$95$2 = N[(N[(t$95$1 / N[(N[(-0.3275911 * N[Abs[x], $MachinePrecision]), $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision] * N[Exp[N[((-x) * x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, N[(N[(1.0 + N[Power[t$95$2, 3.0], $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[(N[Power[N[(t$95$1 / N[(t$95$0 * N[Power[N[Exp[x], $MachinePrecision], x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision] - t$95$2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left|x\right| \cdot 0.3275911 - -1\\
t_1 := \frac{\frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0} + -0.284496736}{t\_0} + 0.254829592\\
t_2 := \frac{t\_1}{-0.3275911 \cdot \left|x\right| - 1} \cdot e^{\left(-x\right) \cdot x}\\
\frac{1 + {t\_2}^{3}}{1 + \left({\left(\frac{t\_1}{t\_0 \cdot {\left(e^{x}\right)}^{x}}\right)}^{2} - t\_2\right)}
\end{array}
\end{array}
Derivation
  1. Initial program 80.1%

    \[1 - \left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-0.284496736 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(1.421413741 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-1.453152027 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|} \]
  2. Add Preprocessing
  3. Applied rewrites80.2%

    \[\leadsto \color{blue}{\frac{1 + {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{-0.3275911 \cdot \left|x\right| + -1} \cdot e^{\left(-x\right) \cdot x}\right)}^{3}}{1 + \left({\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2} - 1 \cdot \left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{-0.3275911 \cdot \left|x\right| + -1} \cdot e^{\left(-x\right) \cdot x}\right)\right)}} \]
  4. Final simplification80.2%

    \[\leadsto \frac{1 + {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{-0.3275911 \cdot \left|x\right| - 1} \cdot e^{\left(-x\right) \cdot x}\right)}^{3}}{1 + \left({\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2} - \frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{-0.3275911 \cdot \left|x\right| - 1} \cdot e^{\left(-x\right) \cdot x}\right)} \]
  5. Add Preprocessing

Alternative 5: 79.2% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left|x\right| \cdot 0.3275911 - -1\\ t_1 := \frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0}\\ t_2 := t\_0 \cdot {\left(e^{x}\right)}^{x}\\ \frac{1 - {\left(\frac{\frac{t\_1 + -0.284496736}{t\_0} + 0.254829592}{t\_2}\right)}^{2}}{\frac{\left(\frac{t\_1}{t\_0} + \frac{-0.284496736}{t\_0}\right) + 0.254829592}{t\_2} - -1} \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (- (* (fabs x) 0.3275911) -1.0))
        (t_1
         (/ (- (/ (- (/ 1.061405429 t_0) 1.453152027) t_0) -1.421413741) t_0))
        (t_2 (* t_0 (pow (exp x) x))))
   (/
    (- 1.0 (pow (/ (+ (/ (+ t_1 -0.284496736) t_0) 0.254829592) t_2) 2.0))
    (- (/ (+ (+ (/ t_1 t_0) (/ -0.284496736 t_0)) 0.254829592) t_2) -1.0))))
double code(double x) {
	double t_0 = (fabs(x) * 0.3275911) - -1.0;
	double t_1 = ((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0;
	double t_2 = t_0 * pow(exp(x), x);
	return (1.0 - pow(((((t_1 + -0.284496736) / t_0) + 0.254829592) / t_2), 2.0)) / (((((t_1 / t_0) + (-0.284496736 / t_0)) + 0.254829592) / t_2) - -1.0);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: t_2
    t_0 = (abs(x) * 0.3275911d0) - (-1.0d0)
    t_1 = ((((1.061405429d0 / t_0) - 1.453152027d0) / t_0) - (-1.421413741d0)) / t_0
    t_2 = t_0 * (exp(x) ** x)
    code = (1.0d0 - (((((t_1 + (-0.284496736d0)) / t_0) + 0.254829592d0) / t_2) ** 2.0d0)) / (((((t_1 / t_0) + ((-0.284496736d0) / t_0)) + 0.254829592d0) / t_2) - (-1.0d0))
end function
public static double code(double x) {
	double t_0 = (Math.abs(x) * 0.3275911) - -1.0;
	double t_1 = ((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0;
	double t_2 = t_0 * Math.pow(Math.exp(x), x);
	return (1.0 - Math.pow(((((t_1 + -0.284496736) / t_0) + 0.254829592) / t_2), 2.0)) / (((((t_1 / t_0) + (-0.284496736 / t_0)) + 0.254829592) / t_2) - -1.0);
}
def code(x):
	t_0 = (math.fabs(x) * 0.3275911) - -1.0
	t_1 = ((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0
	t_2 = t_0 * math.pow(math.exp(x), x)
	return (1.0 - math.pow(((((t_1 + -0.284496736) / t_0) + 0.254829592) / t_2), 2.0)) / (((((t_1 / t_0) + (-0.284496736 / t_0)) + 0.254829592) / t_2) - -1.0)
function code(x)
	t_0 = Float64(Float64(abs(x) * 0.3275911) - -1.0)
	t_1 = Float64(Float64(Float64(Float64(Float64(1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0)
	t_2 = Float64(t_0 * (exp(x) ^ x))
	return Float64(Float64(1.0 - (Float64(Float64(Float64(Float64(t_1 + -0.284496736) / t_0) + 0.254829592) / t_2) ^ 2.0)) / Float64(Float64(Float64(Float64(Float64(t_1 / t_0) + Float64(-0.284496736 / t_0)) + 0.254829592) / t_2) - -1.0))
end
function tmp = code(x)
	t_0 = (abs(x) * 0.3275911) - -1.0;
	t_1 = ((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0;
	t_2 = t_0 * (exp(x) ^ x);
	tmp = (1.0 - (((((t_1 + -0.284496736) / t_0) + 0.254829592) / t_2) ^ 2.0)) / (((((t_1 / t_0) + (-0.284496736 / t_0)) + 0.254829592) / t_2) - -1.0);
end
code[x_] := Block[{t$95$0 = N[(N[(N[Abs[x], $MachinePrecision] * 0.3275911), $MachinePrecision] - -1.0), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(N[(N[(1.061405429 / t$95$0), $MachinePrecision] - 1.453152027), $MachinePrecision] / t$95$0), $MachinePrecision] - -1.421413741), $MachinePrecision] / t$95$0), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$0 * N[Power[N[Exp[x], $MachinePrecision], x], $MachinePrecision]), $MachinePrecision]}, N[(N[(1.0 - N[Power[N[(N[(N[(N[(t$95$1 + -0.284496736), $MachinePrecision] / t$95$0), $MachinePrecision] + 0.254829592), $MachinePrecision] / t$95$2), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision] / N[(N[(N[(N[(N[(t$95$1 / t$95$0), $MachinePrecision] + N[(-0.284496736 / t$95$0), $MachinePrecision]), $MachinePrecision] + 0.254829592), $MachinePrecision] / t$95$2), $MachinePrecision] - -1.0), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left|x\right| \cdot 0.3275911 - -1\\
t_1 := \frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0}\\
t_2 := t\_0 \cdot {\left(e^{x}\right)}^{x}\\
\frac{1 - {\left(\frac{\frac{t\_1 + -0.284496736}{t\_0} + 0.254829592}{t\_2}\right)}^{2}}{\frac{\left(\frac{t\_1}{t\_0} + \frac{-0.284496736}{t\_0}\right) + 0.254829592}{t\_2} - -1}
\end{array}
\end{array}
Derivation
  1. Initial program 80.1%

    \[1 - \left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-0.284496736 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(1.421413741 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-1.453152027 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|} \]
  2. Add Preprocessing
  3. Applied rewrites80.1%

    \[\leadsto \color{blue}{\frac{1 - {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}{\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}} + 1}} \]
  4. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \frac{1 - {\left(\frac{\frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{31853699}{125000000}}{\left(\left|x\right| \cdot \frac{3275911}{10000000} - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}{\frac{\color{blue}{\frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1}} + \frac{31853699}{125000000}}{\left(\left|x\right| \cdot \frac{3275911}{10000000} - -1\right) \cdot {\left(e^{x}\right)}^{x}} + 1} \]
    2. lift-+.f64N/A

      \[\leadsto \frac{1 - {\left(\frac{\frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{31853699}{125000000}}{\left(\left|x\right| \cdot \frac{3275911}{10000000} - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}{\frac{\frac{\color{blue}{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{31853699}{125000000}}{\left(\left|x\right| \cdot \frac{3275911}{10000000} - -1\right) \cdot {\left(e^{x}\right)}^{x}} + 1} \]
    3. div-addN/A

      \[\leadsto \frac{1 - {\left(\frac{\frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{31853699}{125000000}}{\left(\left|x\right| \cdot \frac{3275911}{10000000} - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}{\frac{\color{blue}{\left(\frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{\frac{-8890523}{31250000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1}\right)} + \frac{31853699}{125000000}}{\left(\left|x\right| \cdot \frac{3275911}{10000000} - -1\right) \cdot {\left(e^{x}\right)}^{x}} + 1} \]
    4. lower-+.f64N/A

      \[\leadsto \frac{1 - {\left(\frac{\frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{31853699}{125000000}}{\left(\left|x\right| \cdot \frac{3275911}{10000000} - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}{\frac{\color{blue}{\left(\frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{\frac{-8890523}{31250000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1}\right)} + \frac{31853699}{125000000}}{\left(\left|x\right| \cdot \frac{3275911}{10000000} - -1\right) \cdot {\left(e^{x}\right)}^{x}} + 1} \]
    5. lower-/.f64N/A

      \[\leadsto \frac{1 - {\left(\frac{\frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{31853699}{125000000}}{\left(\left|x\right| \cdot \frac{3275911}{10000000} - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}{\frac{\left(\color{blue}{\frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1}} + \frac{\frac{-8890523}{31250000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1}\right) + \frac{31853699}{125000000}}{\left(\left|x\right| \cdot \frac{3275911}{10000000} - -1\right) \cdot {\left(e^{x}\right)}^{x}} + 1} \]
    6. lower-/.f6480.1

      \[\leadsto \frac{1 - {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}{\frac{\left(\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1}}{\left|x\right| \cdot 0.3275911 - -1} + \color{blue}{\frac{-0.284496736}{\left|x\right| \cdot 0.3275911 - -1}}\right) + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}} + 1} \]
  5. Applied rewrites80.1%

    \[\leadsto \frac{1 - {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}{\frac{\color{blue}{\left(\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1}}{\left|x\right| \cdot 0.3275911 - -1} + \frac{-0.284496736}{\left|x\right| \cdot 0.3275911 - -1}\right)} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}} + 1} \]
  6. Final simplification80.1%

    \[\leadsto \frac{1 - {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}{\frac{\left(\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1}}{\left|x\right| \cdot 0.3275911 - -1} + \frac{-0.284496736}{\left|x\right| \cdot 0.3275911 - -1}\right) + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}} - -1} \]
  7. Add Preprocessing

Alternative 6: 79.2% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left|x\right| \cdot 0.3275911 - -1\\ t_1 := \frac{\frac{\frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0} + -0.284496736}{t\_0} + 0.254829592}{t\_0 \cdot {\left(e^{x}\right)}^{x}}\\ \frac{1 - {t\_1}^{2}}{t\_1 - -1} \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (- (* (fabs x) 0.3275911) -1.0))
        (t_1
         (/
          (+
           (/
            (+
             (/
              (- (/ (- (/ 1.061405429 t_0) 1.453152027) t_0) -1.421413741)
              t_0)
             -0.284496736)
            t_0)
           0.254829592)
          (* t_0 (pow (exp x) x)))))
   (/ (- 1.0 (pow t_1 2.0)) (- t_1 -1.0))))
double code(double x) {
	double t_0 = (fabs(x) * 0.3275911) - -1.0;
	double t_1 = ((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / (t_0 * pow(exp(x), x));
	return (1.0 - pow(t_1, 2.0)) / (t_1 - -1.0);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: t_1
    t_0 = (abs(x) * 0.3275911d0) - (-1.0d0)
    t_1 = ((((((((1.061405429d0 / t_0) - 1.453152027d0) / t_0) - (-1.421413741d0)) / t_0) + (-0.284496736d0)) / t_0) + 0.254829592d0) / (t_0 * (exp(x) ** x))
    code = (1.0d0 - (t_1 ** 2.0d0)) / (t_1 - (-1.0d0))
end function
public static double code(double x) {
	double t_0 = (Math.abs(x) * 0.3275911) - -1.0;
	double t_1 = ((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / (t_0 * Math.pow(Math.exp(x), x));
	return (1.0 - Math.pow(t_1, 2.0)) / (t_1 - -1.0);
}
def code(x):
	t_0 = (math.fabs(x) * 0.3275911) - -1.0
	t_1 = ((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / (t_0 * math.pow(math.exp(x), x))
	return (1.0 - math.pow(t_1, 2.0)) / (t_1 - -1.0)
function code(x)
	t_0 = Float64(Float64(abs(x) * 0.3275911) - -1.0)
	t_1 = Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / Float64(t_0 * (exp(x) ^ x)))
	return Float64(Float64(1.0 - (t_1 ^ 2.0)) / Float64(t_1 - -1.0))
end
function tmp = code(x)
	t_0 = (abs(x) * 0.3275911) - -1.0;
	t_1 = ((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / (t_0 * (exp(x) ^ x));
	tmp = (1.0 - (t_1 ^ 2.0)) / (t_1 - -1.0);
end
code[x_] := Block[{t$95$0 = N[(N[(N[Abs[x], $MachinePrecision] * 0.3275911), $MachinePrecision] - -1.0), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(N[(N[(N[(N[(N[(N[(1.061405429 / t$95$0), $MachinePrecision] - 1.453152027), $MachinePrecision] / t$95$0), $MachinePrecision] - -1.421413741), $MachinePrecision] / t$95$0), $MachinePrecision] + -0.284496736), $MachinePrecision] / t$95$0), $MachinePrecision] + 0.254829592), $MachinePrecision] / N[(t$95$0 * N[Power[N[Exp[x], $MachinePrecision], x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(N[(1.0 - N[Power[t$95$1, 2.0], $MachinePrecision]), $MachinePrecision] / N[(t$95$1 - -1.0), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left|x\right| \cdot 0.3275911 - -1\\
t_1 := \frac{\frac{\frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0} + -0.284496736}{t\_0} + 0.254829592}{t\_0 \cdot {\left(e^{x}\right)}^{x}}\\
\frac{1 - {t\_1}^{2}}{t\_1 - -1}
\end{array}
\end{array}
Derivation
  1. Initial program 80.1%

    \[1 - \left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-0.284496736 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(1.421413741 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-1.453152027 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|} \]
  2. Add Preprocessing
  3. Applied rewrites80.1%

    \[\leadsto \color{blue}{\frac{1 - {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}{\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}} + 1}} \]
  4. Final simplification80.1%

    \[\leadsto \frac{1 - {\left(\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}}\right)}^{2}}{\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left(\left|x\right| \cdot 0.3275911 - -1\right) \cdot {\left(e^{x}\right)}^{x}} - -1} \]
  5. Add Preprocessing

Alternative 7: 79.2% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 0.3275911 \cdot \left|x\right| - -1\\ t_1 := e^{\left(-x\right) \cdot x} \cdot \frac{0.254829592 + \frac{-0.284496736 + \frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0}}{t\_0}}{t\_0}\\ \frac{1 - t\_1 \cdot t\_1}{1 + t\_1} \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (- (* 0.3275911 (fabs x)) -1.0))
        (t_1
         (*
          (exp (* (- x) x))
          (/
           (+
            0.254829592
            (/
             (+
              -0.284496736
              (/
               (- (/ (- (/ 1.061405429 t_0) 1.453152027) t_0) -1.421413741)
               t_0))
             t_0))
           t_0))))
   (/ (- 1.0 (* t_1 t_1)) (+ 1.0 t_1))))
double code(double x) {
	double t_0 = (0.3275911 * fabs(x)) - -1.0;
	double t_1 = exp((-x * x)) * ((0.254829592 + ((-0.284496736 + (((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0)) / t_0)) / t_0);
	return (1.0 - (t_1 * t_1)) / (1.0 + t_1);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: t_1
    t_0 = (0.3275911d0 * abs(x)) - (-1.0d0)
    t_1 = exp((-x * x)) * ((0.254829592d0 + (((-0.284496736d0) + (((((1.061405429d0 / t_0) - 1.453152027d0) / t_0) - (-1.421413741d0)) / t_0)) / t_0)) / t_0)
    code = (1.0d0 - (t_1 * t_1)) / (1.0d0 + t_1)
end function
public static double code(double x) {
	double t_0 = (0.3275911 * Math.abs(x)) - -1.0;
	double t_1 = Math.exp((-x * x)) * ((0.254829592 + ((-0.284496736 + (((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0)) / t_0)) / t_0);
	return (1.0 - (t_1 * t_1)) / (1.0 + t_1);
}
def code(x):
	t_0 = (0.3275911 * math.fabs(x)) - -1.0
	t_1 = math.exp((-x * x)) * ((0.254829592 + ((-0.284496736 + (((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0)) / t_0)) / t_0)
	return (1.0 - (t_1 * t_1)) / (1.0 + t_1)
function code(x)
	t_0 = Float64(Float64(0.3275911 * abs(x)) - -1.0)
	t_1 = Float64(exp(Float64(Float64(-x) * x)) * Float64(Float64(0.254829592 + Float64(Float64(-0.284496736 + Float64(Float64(Float64(Float64(Float64(1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0)) / t_0)) / t_0))
	return Float64(Float64(1.0 - Float64(t_1 * t_1)) / Float64(1.0 + t_1))
end
function tmp = code(x)
	t_0 = (0.3275911 * abs(x)) - -1.0;
	t_1 = exp((-x * x)) * ((0.254829592 + ((-0.284496736 + (((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0)) / t_0)) / t_0);
	tmp = (1.0 - (t_1 * t_1)) / (1.0 + t_1);
end
code[x_] := Block[{t$95$0 = N[(N[(0.3275911 * N[Abs[x], $MachinePrecision]), $MachinePrecision] - -1.0), $MachinePrecision]}, Block[{t$95$1 = N[(N[Exp[N[((-x) * x), $MachinePrecision]], $MachinePrecision] * N[(N[(0.254829592 + N[(N[(-0.284496736 + N[(N[(N[(N[(N[(1.061405429 / t$95$0), $MachinePrecision] - 1.453152027), $MachinePrecision] / t$95$0), $MachinePrecision] - -1.421413741), $MachinePrecision] / t$95$0), $MachinePrecision]), $MachinePrecision] / t$95$0), $MachinePrecision]), $MachinePrecision] / t$95$0), $MachinePrecision]), $MachinePrecision]}, N[(N[(1.0 - N[(t$95$1 * t$95$1), $MachinePrecision]), $MachinePrecision] / N[(1.0 + t$95$1), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := 0.3275911 \cdot \left|x\right| - -1\\
t_1 := e^{\left(-x\right) \cdot x} \cdot \frac{0.254829592 + \frac{-0.284496736 + \frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0}}{t\_0}}{t\_0}\\
\frac{1 - t\_1 \cdot t\_1}{1 + t\_1}
\end{array}
\end{array}
Derivation
  1. Initial program 80.1%

    \[1 - \left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-0.284496736 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(1.421413741 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-1.453152027 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|} \]
  2. Add Preprocessing
  3. Applied rewrites80.1%

    \[\leadsto 1 - \color{blue}{\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left|x\right| \cdot 0.3275911 - -1} \cdot e^{\left(-x\right) \cdot x}} \]
  4. Applied rewrites80.1%

    \[\leadsto \color{blue}{\frac{1 - \left(e^{\left(-x\right) \cdot x} \cdot \frac{0.254829592 + \frac{-0.284496736 + \frac{\frac{\frac{1.061405429}{0.3275911 \cdot \left|x\right| - -1} - 1.453152027}{0.3275911 \cdot \left|x\right| - -1} - -1.421413741}{0.3275911 \cdot \left|x\right| - -1}}{0.3275911 \cdot \left|x\right| - -1}}{0.3275911 \cdot \left|x\right| - -1}\right) \cdot \left(e^{\left(-x\right) \cdot x} \cdot \frac{0.254829592 + \frac{-0.284496736 + \frac{\frac{\frac{1.061405429}{0.3275911 \cdot \left|x\right| - -1} - 1.453152027}{0.3275911 \cdot \left|x\right| - -1} - -1.421413741}{0.3275911 \cdot \left|x\right| - -1}}{0.3275911 \cdot \left|x\right| - -1}}{0.3275911 \cdot \left|x\right| - -1}\right)}{1 + e^{\left(-x\right) \cdot x} \cdot \frac{0.254829592 + \frac{-0.284496736 + \frac{\frac{\frac{1.061405429}{0.3275911 \cdot \left|x\right| - -1} - 1.453152027}{0.3275911 \cdot \left|x\right| - -1} - -1.421413741}{0.3275911 \cdot \left|x\right| - -1}}{0.3275911 \cdot \left|x\right| - -1}}{0.3275911 \cdot \left|x\right| - -1}}} \]
  5. Add Preprocessing

Alternative 8: 79.2% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left|x\right| \cdot 0.3275911\\ t_1 := t\_0 - -1\\ 1 - \left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{\frac{\frac{\frac{1.061405429}{t\_1} - 1.453152027}{t\_1} - -1.421413741}{t\_1} + -0.284496736}{1 - 0.10731592879921 \cdot \left(x \cdot x\right)} \cdot \left(1 - t\_0\right)\right)\right) \cdot e^{\left(-x\right) \cdot x} \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (* (fabs x) 0.3275911)) (t_1 (- t_0 -1.0)))
   (-
    1.0
    (*
     (*
      (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
      (+
       0.254829592
       (*
        (/
         (+
          (/ (- (/ (- (/ 1.061405429 t_1) 1.453152027) t_1) -1.421413741) t_1)
          -0.284496736)
         (- 1.0 (* 0.10731592879921 (* x x))))
        (- 1.0 t_0))))
     (exp (* (- x) x))))))
double code(double x) {
	double t_0 = fabs(x) * 0.3275911;
	double t_1 = t_0 - -1.0;
	return 1.0 - (((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (0.254829592 + ((((((((1.061405429 / t_1) - 1.453152027) / t_1) - -1.421413741) / t_1) + -0.284496736) / (1.0 - (0.10731592879921 * (x * x)))) * (1.0 - t_0)))) * exp((-x * x)));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: t_1
    t_0 = abs(x) * 0.3275911d0
    t_1 = t_0 - (-1.0d0)
    code = 1.0d0 - (((1.0d0 / (1.0d0 + (0.3275911d0 * abs(x)))) * (0.254829592d0 + ((((((((1.061405429d0 / t_1) - 1.453152027d0) / t_1) - (-1.421413741d0)) / t_1) + (-0.284496736d0)) / (1.0d0 - (0.10731592879921d0 * (x * x)))) * (1.0d0 - t_0)))) * exp((-x * x)))
end function
public static double code(double x) {
	double t_0 = Math.abs(x) * 0.3275911;
	double t_1 = t_0 - -1.0;
	return 1.0 - (((1.0 / (1.0 + (0.3275911 * Math.abs(x)))) * (0.254829592 + ((((((((1.061405429 / t_1) - 1.453152027) / t_1) - -1.421413741) / t_1) + -0.284496736) / (1.0 - (0.10731592879921 * (x * x)))) * (1.0 - t_0)))) * Math.exp((-x * x)));
}
def code(x):
	t_0 = math.fabs(x) * 0.3275911
	t_1 = t_0 - -1.0
	return 1.0 - (((1.0 / (1.0 + (0.3275911 * math.fabs(x)))) * (0.254829592 + ((((((((1.061405429 / t_1) - 1.453152027) / t_1) - -1.421413741) / t_1) + -0.284496736) / (1.0 - (0.10731592879921 * (x * x)))) * (1.0 - t_0)))) * math.exp((-x * x)))
function code(x)
	t_0 = Float64(abs(x) * 0.3275911)
	t_1 = Float64(t_0 - -1.0)
	return Float64(1.0 - Float64(Float64(Float64(1.0 / Float64(1.0 + Float64(0.3275911 * abs(x)))) * Float64(0.254829592 + Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(1.061405429 / t_1) - 1.453152027) / t_1) - -1.421413741) / t_1) + -0.284496736) / Float64(1.0 - Float64(0.10731592879921 * Float64(x * x)))) * Float64(1.0 - t_0)))) * exp(Float64(Float64(-x) * x))))
end
function tmp = code(x)
	t_0 = abs(x) * 0.3275911;
	t_1 = t_0 - -1.0;
	tmp = 1.0 - (((1.0 / (1.0 + (0.3275911 * abs(x)))) * (0.254829592 + ((((((((1.061405429 / t_1) - 1.453152027) / t_1) - -1.421413741) / t_1) + -0.284496736) / (1.0 - (0.10731592879921 * (x * x)))) * (1.0 - t_0)))) * exp((-x * x)));
end
code[x_] := Block[{t$95$0 = N[(N[Abs[x], $MachinePrecision] * 0.3275911), $MachinePrecision]}, Block[{t$95$1 = N[(t$95$0 - -1.0), $MachinePrecision]}, N[(1.0 - N[(N[(N[(1.0 / N[(1.0 + N[(0.3275911 * N[Abs[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(0.254829592 + N[(N[(N[(N[(N[(N[(N[(N[(1.061405429 / t$95$1), $MachinePrecision] - 1.453152027), $MachinePrecision] / t$95$1), $MachinePrecision] - -1.421413741), $MachinePrecision] / t$95$1), $MachinePrecision] + -0.284496736), $MachinePrecision] / N[(1.0 - N[(0.10731592879921 * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(1.0 - t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Exp[N[((-x) * x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left|x\right| \cdot 0.3275911\\
t_1 := t\_0 - -1\\
1 - \left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{\frac{\frac{\frac{1.061405429}{t\_1} - 1.453152027}{t\_1} - -1.421413741}{t\_1} + -0.284496736}{1 - 0.10731592879921 \cdot \left(x \cdot x\right)} \cdot \left(1 - t\_0\right)\right)\right) \cdot e^{\left(-x\right) \cdot x}
\end{array}
\end{array}
Derivation
  1. Initial program 80.1%

    \[1 - \left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-0.284496736 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(1.421413741 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-1.453152027 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|} \]
  2. Add Preprocessing
  3. Applied rewrites80.1%

    \[\leadsto 1 - \left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \color{blue}{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{1 - 0.10731592879921 \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot 0.3275911\right)}\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|} \]
  4. Taylor expanded in x around 0

    \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot \color{blue}{e^{\mathsf{neg}\left({\left(\left|x\right|\right)}^{2}\right)}} \]
  5. Step-by-step derivation
    1. lift-fabs.f64N/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\mathsf{neg}\left({\left(\left|\color{blue}{x}\right|\right)}^{2}\right)} \]
    2. lift-fabs.f64N/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\mathsf{neg}\left({\left(\left|x\right|\right)}^{2}\right)} \]
    3. pow2N/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\mathsf{neg}\left({\color{blue}{\left(\left|x\right|\right)}}^{2}\right)} \]
    4. lift-fabs.f64N/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\mathsf{neg}\left({\left(\left|\color{blue}{x}\right|\right)}^{2}\right)} \]
    5. lift-fabs.f64N/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\mathsf{neg}\left({\left(\left|\color{blue}{x}\right|\right)}^{2}\right)} \]
    6. pow2N/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\mathsf{neg}\left({\color{blue}{\left(\left|x\right|\right)}}^{2}\right)} \]
    7. lift-fabs.f64N/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\mathsf{neg}\left({\left(\left|\color{blue}{x}\right|\right)}^{2}\right)} \]
    8. lift-fabs.f64N/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\mathsf{neg}\left({\left(\left|x\right|\right)}^{2}\right)} \]
    9. sqr-abs-revN/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\mathsf{neg}\left({\color{blue}{\left(\left|x\right|\right)}}^{2}\right)} \]
    10. distribute-lft-neg-outN/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\mathsf{neg}\left(\color{blue}{{\left(\left|x\right|\right)}^{2}}\right)} \]
    11. lift-fabs.f64N/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\mathsf{neg}\left({\left(\left|x\right|\right)}^{2}\right)} \]
    12. pow2N/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\mathsf{neg}\left(\left|x\right| \cdot \left|x\right|\right)} \]
    13. lift-fabs.f64N/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\mathsf{neg}\left(\left|x\right| \cdot \left|x\right|\right)} \]
    14. lift-fabs.f64N/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\mathsf{neg}\left(\left|x\right| \cdot \left|x\right|\right)} \]
    15. sqr-abs-revN/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\mathsf{neg}\left(x \cdot x\right)} \]
    16. pow2N/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\mathsf{neg}\left({x}^{2}\right)} \]
    17. lower-exp.f64N/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\mathsf{neg}\left({x}^{2}\right)} \]
    18. pow2N/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\mathsf{neg}\left(x \cdot x\right)} \]
    19. distribute-lft-neg-outN/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\left(\mathsf{neg}\left(x\right)\right) \cdot x} \]
    20. lift-*.f64N/A

      \[\leadsto 1 - \left(\frac{1}{1 + \frac{3275911}{10000000} \cdot \left|x\right|} \cdot \left(\frac{31853699}{125000000} + \frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{1 - \frac{10731592879921}{100000000000000} \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot \frac{3275911}{10000000}\right)\right)\right) \cdot e^{\left(\mathsf{neg}\left(x\right)\right) \cdot x} \]
  6. Applied rewrites80.1%

    \[\leadsto 1 - \left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{1 - 0.10731592879921 \cdot \left(x \cdot x\right)} \cdot \left(1 - \left|x\right| \cdot 0.3275911\right)\right)\right) \cdot \color{blue}{e^{\left(-x\right) \cdot x}} \]
  7. Add Preprocessing

Alternative 9: 79.1% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left|x\right| \cdot 0.3275911 - -1\\ 1 + \left(\frac{-1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(\frac{\frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0} + -0.284496736}{t\_0} + 0.254829592\right)\right) \cdot e^{\left(-x\right) \cdot x} \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (- (* (fabs x) 0.3275911) -1.0)))
   (+
    1.0
    (*
     (*
      (/ -1.0 (+ 1.0 (* 0.3275911 (fabs x))))
      (+
       (/
        (+
         (/ (- (/ (- (/ 1.061405429 t_0) 1.453152027) t_0) -1.421413741) t_0)
         -0.284496736)
        t_0)
       0.254829592))
     (exp (* (- x) x))))))
double code(double x) {
	double t_0 = (fabs(x) * 0.3275911) - -1.0;
	return 1.0 + (((-1.0 / (1.0 + (0.3275911 * fabs(x)))) * ((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592)) * exp((-x * x)));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8) :: t_0
    t_0 = (abs(x) * 0.3275911d0) - (-1.0d0)
    code = 1.0d0 + ((((-1.0d0) / (1.0d0 + (0.3275911d0 * abs(x)))) * ((((((((1.061405429d0 / t_0) - 1.453152027d0) / t_0) - (-1.421413741d0)) / t_0) + (-0.284496736d0)) / t_0) + 0.254829592d0)) * exp((-x * x)))
end function
public static double code(double x) {
	double t_0 = (Math.abs(x) * 0.3275911) - -1.0;
	return 1.0 + (((-1.0 / (1.0 + (0.3275911 * Math.abs(x)))) * ((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592)) * Math.exp((-x * x)));
}
def code(x):
	t_0 = (math.fabs(x) * 0.3275911) - -1.0
	return 1.0 + (((-1.0 / (1.0 + (0.3275911 * math.fabs(x)))) * ((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592)) * math.exp((-x * x)))
function code(x)
	t_0 = Float64(Float64(abs(x) * 0.3275911) - -1.0)
	return Float64(1.0 + Float64(Float64(Float64(-1.0 / Float64(1.0 + Float64(0.3275911 * abs(x)))) * Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592)) * exp(Float64(Float64(-x) * x))))
end
function tmp = code(x)
	t_0 = (abs(x) * 0.3275911) - -1.0;
	tmp = 1.0 + (((-1.0 / (1.0 + (0.3275911 * abs(x)))) * ((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592)) * exp((-x * x)));
end
code[x_] := Block[{t$95$0 = N[(N[(N[Abs[x], $MachinePrecision] * 0.3275911), $MachinePrecision] - -1.0), $MachinePrecision]}, N[(1.0 + N[(N[(N[(-1.0 / N[(1.0 + N[(0.3275911 * N[Abs[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(N[(N[(N[(N[(N[(N[(N[(1.061405429 / t$95$0), $MachinePrecision] - 1.453152027), $MachinePrecision] / t$95$0), $MachinePrecision] - -1.421413741), $MachinePrecision] / t$95$0), $MachinePrecision] + -0.284496736), $MachinePrecision] / t$95$0), $MachinePrecision] + 0.254829592), $MachinePrecision]), $MachinePrecision] * N[Exp[N[((-x) * x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left|x\right| \cdot 0.3275911 - -1\\
1 + \left(\frac{-1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(\frac{\frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0} + -0.284496736}{t\_0} + 0.254829592\right)\right) \cdot e^{\left(-x\right) \cdot x}
\end{array}
\end{array}
Derivation
  1. Initial program 80.1%

    \[1 - \left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-0.284496736 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(1.421413741 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-1.453152027 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|} \]
  2. Add Preprocessing
  3. Applied rewrites80.1%

    \[\leadsto 1 - \left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \color{blue}{\left(\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592\right)}\right) \cdot e^{-\left|x\right| \cdot \left|x\right|} \]
  4. Final simplification80.1%

    \[\leadsto 1 + \left(\frac{-1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592\right)\right) \cdot e^{\left(-x\right) \cdot x} \]
  5. Add Preprocessing

Alternative 10: 79.1% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left|x\right| \cdot 0.3275911 - -1\\ 1 - \frac{\frac{\frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0} + -0.284496736}{t\_0} + 0.254829592}{t\_0} \cdot e^{\left(-x\right) \cdot x} \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (- (* (fabs x) 0.3275911) -1.0)))
   (-
    1.0
    (*
     (/
      (+
       (/
        (+
         (/ (- (/ (- (/ 1.061405429 t_0) 1.453152027) t_0) -1.421413741) t_0)
         -0.284496736)
        t_0)
       0.254829592)
      t_0)
     (exp (* (- x) x))))))
double code(double x) {
	double t_0 = (fabs(x) * 0.3275911) - -1.0;
	return 1.0 - ((((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / t_0) * exp((-x * x)));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8) :: t_0
    t_0 = (abs(x) * 0.3275911d0) - (-1.0d0)
    code = 1.0d0 - ((((((((((1.061405429d0 / t_0) - 1.453152027d0) / t_0) - (-1.421413741d0)) / t_0) + (-0.284496736d0)) / t_0) + 0.254829592d0) / t_0) * exp((-x * x)))
end function
public static double code(double x) {
	double t_0 = (Math.abs(x) * 0.3275911) - -1.0;
	return 1.0 - ((((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / t_0) * Math.exp((-x * x)));
}
def code(x):
	t_0 = (math.fabs(x) * 0.3275911) - -1.0
	return 1.0 - ((((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / t_0) * math.exp((-x * x)))
function code(x)
	t_0 = Float64(Float64(abs(x) * 0.3275911) - -1.0)
	return Float64(1.0 - Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / t_0) * exp(Float64(Float64(-x) * x))))
end
function tmp = code(x)
	t_0 = (abs(x) * 0.3275911) - -1.0;
	tmp = 1.0 - ((((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / t_0) * exp((-x * x)));
end
code[x_] := Block[{t$95$0 = N[(N[(N[Abs[x], $MachinePrecision] * 0.3275911), $MachinePrecision] - -1.0), $MachinePrecision]}, N[(1.0 - N[(N[(N[(N[(N[(N[(N[(N[(N[(N[(1.061405429 / t$95$0), $MachinePrecision] - 1.453152027), $MachinePrecision] / t$95$0), $MachinePrecision] - -1.421413741), $MachinePrecision] / t$95$0), $MachinePrecision] + -0.284496736), $MachinePrecision] / t$95$0), $MachinePrecision] + 0.254829592), $MachinePrecision] / t$95$0), $MachinePrecision] * N[Exp[N[((-x) * x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left|x\right| \cdot 0.3275911 - -1\\
1 - \frac{\frac{\frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0} + -0.284496736}{t\_0} + 0.254829592}{t\_0} \cdot e^{\left(-x\right) \cdot x}
\end{array}
\end{array}
Derivation
  1. Initial program 80.1%

    \[1 - \left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-0.284496736 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(1.421413741 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-1.453152027 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|} \]
  2. Add Preprocessing
  3. Applied rewrites80.1%

    \[\leadsto 1 - \color{blue}{\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left|x\right| \cdot 0.3275911 - -1} \cdot e^{\left(-x\right) \cdot x}} \]
  4. Add Preprocessing

Alternative 11: 77.6% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left|x\right| \cdot 0.3275911 - -1\\ 1 - \frac{\left(\frac{\frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0}}{t\_0} + \frac{-0.284496736}{t\_0}\right) + 0.254829592}{t\_0} \cdot 1 \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (- (* (fabs x) 0.3275911) -1.0)))
   (-
    1.0
    (*
     (/
      (+
       (+
        (/
         (/ (- (/ (- (/ 1.061405429 t_0) 1.453152027) t_0) -1.421413741) t_0)
         t_0)
        (/ -0.284496736 t_0))
       0.254829592)
      t_0)
     1.0))))
double code(double x) {
	double t_0 = (fabs(x) * 0.3275911) - -1.0;
	return 1.0 - ((((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) / t_0) + (-0.284496736 / t_0)) + 0.254829592) / t_0) * 1.0);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8) :: t_0
    t_0 = (abs(x) * 0.3275911d0) - (-1.0d0)
    code = 1.0d0 - ((((((((((1.061405429d0 / t_0) - 1.453152027d0) / t_0) - (-1.421413741d0)) / t_0) / t_0) + ((-0.284496736d0) / t_0)) + 0.254829592d0) / t_0) * 1.0d0)
end function
public static double code(double x) {
	double t_0 = (Math.abs(x) * 0.3275911) - -1.0;
	return 1.0 - ((((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) / t_0) + (-0.284496736 / t_0)) + 0.254829592) / t_0) * 1.0);
}
def code(x):
	t_0 = (math.fabs(x) * 0.3275911) - -1.0
	return 1.0 - ((((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) / t_0) + (-0.284496736 / t_0)) + 0.254829592) / t_0) * 1.0)
function code(x)
	t_0 = Float64(Float64(abs(x) * 0.3275911) - -1.0)
	return Float64(1.0 - Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) / t_0) + Float64(-0.284496736 / t_0)) + 0.254829592) / t_0) * 1.0))
end
function tmp = code(x)
	t_0 = (abs(x) * 0.3275911) - -1.0;
	tmp = 1.0 - ((((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) / t_0) + (-0.284496736 / t_0)) + 0.254829592) / t_0) * 1.0);
end
code[x_] := Block[{t$95$0 = N[(N[(N[Abs[x], $MachinePrecision] * 0.3275911), $MachinePrecision] - -1.0), $MachinePrecision]}, N[(1.0 - N[(N[(N[(N[(N[(N[(N[(N[(N[(N[(1.061405429 / t$95$0), $MachinePrecision] - 1.453152027), $MachinePrecision] / t$95$0), $MachinePrecision] - -1.421413741), $MachinePrecision] / t$95$0), $MachinePrecision] / t$95$0), $MachinePrecision] + N[(-0.284496736 / t$95$0), $MachinePrecision]), $MachinePrecision] + 0.254829592), $MachinePrecision] / t$95$0), $MachinePrecision] * 1.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left|x\right| \cdot 0.3275911 - -1\\
1 - \frac{\left(\frac{\frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0}}{t\_0} + \frac{-0.284496736}{t\_0}\right) + 0.254829592}{t\_0} \cdot 1
\end{array}
\end{array}
Derivation
  1. Initial program 80.1%

    \[1 - \left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-0.284496736 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(1.421413741 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-1.453152027 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|} \]
  2. Add Preprocessing
  3. Applied rewrites80.1%

    \[\leadsto 1 - \color{blue}{\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left|x\right| \cdot 0.3275911 - -1} \cdot e^{\left(-x\right) \cdot x}} \]
  4. Taylor expanded in x around 0

    \[\leadsto 1 - \frac{\frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{31853699}{125000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} \cdot \color{blue}{1} \]
  5. Step-by-step derivation
    1. Applied rewrites78.8%

      \[\leadsto 1 - \frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left|x\right| \cdot 0.3275911 - -1} \cdot \color{blue}{1} \]
    2. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto 1 - \frac{\color{blue}{\frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1}} + \frac{31853699}{125000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} \cdot 1 \]
      2. lift-+.f64N/A

        \[\leadsto 1 - \frac{\frac{\color{blue}{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{31853699}{125000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} \cdot 1 \]
      3. div-addN/A

        \[\leadsto 1 - \frac{\color{blue}{\left(\frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{\frac{-8890523}{31250000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1}\right)} + \frac{31853699}{125000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} \cdot 1 \]
      4. lower-+.f64N/A

        \[\leadsto 1 - \frac{\color{blue}{\left(\frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{\frac{-8890523}{31250000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1}\right)} + \frac{31853699}{125000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} \cdot 1 \]
      5. lower-/.f64N/A

        \[\leadsto 1 - \frac{\left(\color{blue}{\frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1}} + \frac{\frac{-8890523}{31250000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1}\right) + \frac{31853699}{125000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} \cdot 1 \]
      6. lower-/.f6478.8

        \[\leadsto 1 - \frac{\left(\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1}}{\left|x\right| \cdot 0.3275911 - -1} + \color{blue}{\frac{-0.284496736}{\left|x\right| \cdot 0.3275911 - -1}}\right) + 0.254829592}{\left|x\right| \cdot 0.3275911 - -1} \cdot 1 \]
    3. Applied rewrites78.8%

      \[\leadsto 1 - \frac{\color{blue}{\left(\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1}}{\left|x\right| \cdot 0.3275911 - -1} + \frac{-0.284496736}{\left|x\right| \cdot 0.3275911 - -1}\right)} + 0.254829592}{\left|x\right| \cdot 0.3275911 - -1} \cdot 1 \]
    4. Add Preprocessing

    Alternative 12: 77.6% accurate, 2.1× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := \left|x\right| \cdot 0.3275911 - -1\\ 1 - \frac{\frac{\frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0} + -0.284496736}{t\_0} + 0.254829592}{t\_0} \cdot 1 \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (let* ((t_0 (- (* (fabs x) 0.3275911) -1.0)))
       (-
        1.0
        (*
         (/
          (+
           (/
            (+
             (/ (- (/ (- (/ 1.061405429 t_0) 1.453152027) t_0) -1.421413741) t_0)
             -0.284496736)
            t_0)
           0.254829592)
          t_0)
         1.0))))
    double code(double x) {
    	double t_0 = (fabs(x) * 0.3275911) - -1.0;
    	return 1.0 - ((((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / t_0) * 1.0);
    }
    
    module fmin_fmax_functions
        implicit none
        private
        public fmax
        public fmin
    
        interface fmax
            module procedure fmax88
            module procedure fmax44
            module procedure fmax84
            module procedure fmax48
        end interface
        interface fmin
            module procedure fmin88
            module procedure fmin44
            module procedure fmin84
            module procedure fmin48
        end interface
    contains
        real(8) function fmax88(x, y) result (res)
            real(8), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(x, max(x, y), y /= y), x /= x)
        end function
        real(4) function fmax44(x, y) result (res)
            real(4), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(y, merge(x, max(x, y), y /= y), x /= x)
        end function
        real(8) function fmax84(x, y) result(res)
            real(8), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
        end function
        real(8) function fmax48(x, y) result(res)
            real(4), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
        end function
        real(8) function fmin88(x, y) result (res)
            real(8), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(x, min(x, y), y /= y), x /= x)
        end function
        real(4) function fmin44(x, y) result (res)
            real(4), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(y, merge(x, min(x, y), y /= y), x /= x)
        end function
        real(8) function fmin84(x, y) result(res)
            real(8), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
        end function
        real(8) function fmin48(x, y) result(res)
            real(4), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
        end function
    end module
    
    real(8) function code(x)
    use fmin_fmax_functions
        real(8), intent (in) :: x
        real(8) :: t_0
        t_0 = (abs(x) * 0.3275911d0) - (-1.0d0)
        code = 1.0d0 - ((((((((((1.061405429d0 / t_0) - 1.453152027d0) / t_0) - (-1.421413741d0)) / t_0) + (-0.284496736d0)) / t_0) + 0.254829592d0) / t_0) * 1.0d0)
    end function
    
    public static double code(double x) {
    	double t_0 = (Math.abs(x) * 0.3275911) - -1.0;
    	return 1.0 - ((((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / t_0) * 1.0);
    }
    
    def code(x):
    	t_0 = (math.fabs(x) * 0.3275911) - -1.0
    	return 1.0 - ((((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / t_0) * 1.0)
    
    function code(x)
    	t_0 = Float64(Float64(abs(x) * 0.3275911) - -1.0)
    	return Float64(1.0 - Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(Float64(1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / t_0) * 1.0))
    end
    
    function tmp = code(x)
    	t_0 = (abs(x) * 0.3275911) - -1.0;
    	tmp = 1.0 - ((((((((((1.061405429 / t_0) - 1.453152027) / t_0) - -1.421413741) / t_0) + -0.284496736) / t_0) + 0.254829592) / t_0) * 1.0);
    end
    
    code[x_] := Block[{t$95$0 = N[(N[(N[Abs[x], $MachinePrecision] * 0.3275911), $MachinePrecision] - -1.0), $MachinePrecision]}, N[(1.0 - N[(N[(N[(N[(N[(N[(N[(N[(N[(N[(1.061405429 / t$95$0), $MachinePrecision] - 1.453152027), $MachinePrecision] / t$95$0), $MachinePrecision] - -1.421413741), $MachinePrecision] / t$95$0), $MachinePrecision] + -0.284496736), $MachinePrecision] / t$95$0), $MachinePrecision] + 0.254829592), $MachinePrecision] / t$95$0), $MachinePrecision] * 1.0), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := \left|x\right| \cdot 0.3275911 - -1\\
    1 - \frac{\frac{\frac{\frac{\frac{1.061405429}{t\_0} - 1.453152027}{t\_0} - -1.421413741}{t\_0} + -0.284496736}{t\_0} + 0.254829592}{t\_0} \cdot 1
    \end{array}
    \end{array}
    
    Derivation
    1. Initial program 80.1%

      \[1 - \left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-0.284496736 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(1.421413741 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-1.453152027 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|} \]
    2. Add Preprocessing
    3. Applied rewrites80.1%

      \[\leadsto 1 - \color{blue}{\frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left|x\right| \cdot 0.3275911 - -1} \cdot e^{\left(-x\right) \cdot x}} \]
    4. Taylor expanded in x around 0

      \[\leadsto 1 - \frac{\frac{\frac{\frac{\frac{\frac{1061405429}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{1453152027}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} - \frac{-1421413741}{1000000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{-8890523}{31250000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} + \frac{31853699}{125000000}}{\left|x\right| \cdot \frac{3275911}{10000000} - -1} \cdot \color{blue}{1} \]
    5. Step-by-step derivation
      1. Applied rewrites78.8%

        \[\leadsto 1 - \frac{\frac{\frac{\frac{\frac{1.061405429}{\left|x\right| \cdot 0.3275911 - -1} - 1.453152027}{\left|x\right| \cdot 0.3275911 - -1} - -1.421413741}{\left|x\right| \cdot 0.3275911 - -1} + -0.284496736}{\left|x\right| \cdot 0.3275911 - -1} + 0.254829592}{\left|x\right| \cdot 0.3275911 - -1} \cdot \color{blue}{1} \]
      2. Add Preprocessing

      Reproduce

      ?
      herbie shell --seed 2025058 
      (FPCore (x)
        :name "Jmat.Real.erf"
        :precision binary64
        (- 1.0 (* (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) (+ 0.254829592 (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) (+ -0.284496736 (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) (+ 1.421413741 (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) (+ -1.453152027 (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) 1.061405429))))))))) (exp (- (* (fabs x) (fabs x)))))))