Maksimov and Kolovsky, Equation (3)

Percentage Accurate: 73.2% → 99.7%
Time: 5.5s
Alternatives: 8
Speedup: 0.4×

Specification

?
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}} \end{array} \end{array} \]
(FPCore (J K U)
 :precision binary64
 (let* ((t_0 (cos (/ K 2.0))))
   (* (* (* -2.0 J) t_0) (sqrt (+ 1.0 (pow (/ U (* (* 2.0 J) t_0)) 2.0))))))
double code(double J, double K, double U) {
	double t_0 = cos((K / 2.0));
	return ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U / ((2.0 * J) * t_0)), 2.0)));
}
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(j, k, u)
use fmin_fmax_functions
    real(8), intent (in) :: j
    real(8), intent (in) :: k
    real(8), intent (in) :: u
    real(8) :: t_0
    t_0 = cos((k / 2.0d0))
    code = (((-2.0d0) * j) * t_0) * sqrt((1.0d0 + ((u / ((2.0d0 * j) * t_0)) ** 2.0d0)))
end function
public static double code(double J, double K, double U) {
	double t_0 = Math.cos((K / 2.0));
	return ((-2.0 * J) * t_0) * Math.sqrt((1.0 + Math.pow((U / ((2.0 * J) * t_0)), 2.0)));
}
def code(J, K, U):
	t_0 = math.cos((K / 2.0))
	return ((-2.0 * J) * t_0) * math.sqrt((1.0 + math.pow((U / ((2.0 * J) * t_0)), 2.0)))
function code(J, K, U)
	t_0 = cos(Float64(K / 2.0))
	return Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U / Float64(Float64(2.0 * J) * t_0)) ^ 2.0))))
end
function tmp = code(J, K, U)
	t_0 = cos((K / 2.0));
	tmp = ((-2.0 * J) * t_0) * sqrt((1.0 + ((U / ((2.0 * J) * t_0)) ^ 2.0)));
end
code[J_, K_, U_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U / N[(N[(2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos \left(\frac{K}{2}\right)\\
\left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}}
\end{array}
\end{array}

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 8 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: 73.2% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}} \end{array} \end{array} \]
(FPCore (J K U)
 :precision binary64
 (let* ((t_0 (cos (/ K 2.0))))
   (* (* (* -2.0 J) t_0) (sqrt (+ 1.0 (pow (/ U (* (* 2.0 J) t_0)) 2.0))))))
double code(double J, double K, double U) {
	double t_0 = cos((K / 2.0));
	return ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U / ((2.0 * J) * t_0)), 2.0)));
}
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(j, k, u)
use fmin_fmax_functions
    real(8), intent (in) :: j
    real(8), intent (in) :: k
    real(8), intent (in) :: u
    real(8) :: t_0
    t_0 = cos((k / 2.0d0))
    code = (((-2.0d0) * j) * t_0) * sqrt((1.0d0 + ((u / ((2.0d0 * j) * t_0)) ** 2.0d0)))
end function
public static double code(double J, double K, double U) {
	double t_0 = Math.cos((K / 2.0));
	return ((-2.0 * J) * t_0) * Math.sqrt((1.0 + Math.pow((U / ((2.0 * J) * t_0)), 2.0)));
}
def code(J, K, U):
	t_0 = math.cos((K / 2.0))
	return ((-2.0 * J) * t_0) * math.sqrt((1.0 + math.pow((U / ((2.0 * J) * t_0)), 2.0)))
function code(J, K, U)
	t_0 = cos(Float64(K / 2.0))
	return Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U / Float64(Float64(2.0 * J) * t_0)) ^ 2.0))))
end
function tmp = code(J, K, U)
	t_0 = cos((K / 2.0));
	tmp = ((-2.0 * J) * t_0) * sqrt((1.0 + ((U / ((2.0 * J) * t_0)) ^ 2.0)));
end
code[J_, K_, U_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U / N[(N[(2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos \left(\frac{K}{2}\right)\\
\left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}}
\end{array}
\end{array}

Alternative 1: 99.7% accurate, 0.3× speedup?

\[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}}\\ t_2 := \cos \left(0.5 \cdot K\right)\\ \mathbf{if}\;t\_1 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_1 \leq 4 \cdot 10^{+306}:\\ \;\;\;\;\left(\left(-2 \cdot J\right) \cdot t\_2\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(J + J\right) \cdot t\_2}\right)}^{2}}\\ \mathbf{else}:\\ \;\;\;\;U\_m\\ \end{array} \end{array} \]
U_m = (fabs.f64 U)
(FPCore (J K U_m)
 :precision binary64
 (let* ((t_0 (cos (/ K 2.0)))
        (t_1
         (*
          (* (* -2.0 J) t_0)
          (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J) t_0)) 2.0)))))
        (t_2 (cos (* 0.5 K))))
   (if (<= t_1 (- INFINITY))
     (- U_m)
     (if (<= t_1 4e+306)
       (* (* (* -2.0 J) t_2) (sqrt (+ 1.0 (pow (/ U_m (* (+ J J) t_2)) 2.0))))
       U_m))))
U_m = fabs(U);
double code(double J, double K, double U_m) {
	double t_0 = cos((K / 2.0));
	double t_1 = ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U_m / ((2.0 * J) * t_0)), 2.0)));
	double t_2 = cos((0.5 * K));
	double tmp;
	if (t_1 <= -((double) INFINITY)) {
		tmp = -U_m;
	} else if (t_1 <= 4e+306) {
		tmp = ((-2.0 * J) * t_2) * sqrt((1.0 + pow((U_m / ((J + J) * t_2)), 2.0)));
	} else {
		tmp = U_m;
	}
	return tmp;
}
U_m = Math.abs(U);
public static double code(double J, double K, double U_m) {
	double t_0 = Math.cos((K / 2.0));
	double t_1 = ((-2.0 * J) * t_0) * Math.sqrt((1.0 + Math.pow((U_m / ((2.0 * J) * t_0)), 2.0)));
	double t_2 = Math.cos((0.5 * K));
	double tmp;
	if (t_1 <= -Double.POSITIVE_INFINITY) {
		tmp = -U_m;
	} else if (t_1 <= 4e+306) {
		tmp = ((-2.0 * J) * t_2) * Math.sqrt((1.0 + Math.pow((U_m / ((J + J) * t_2)), 2.0)));
	} else {
		tmp = U_m;
	}
	return tmp;
}
U_m = math.fabs(U)
def code(J, K, U_m):
	t_0 = math.cos((K / 2.0))
	t_1 = ((-2.0 * J) * t_0) * math.sqrt((1.0 + math.pow((U_m / ((2.0 * J) * t_0)), 2.0)))
	t_2 = math.cos((0.5 * K))
	tmp = 0
	if t_1 <= -math.inf:
		tmp = -U_m
	elif t_1 <= 4e+306:
		tmp = ((-2.0 * J) * t_2) * math.sqrt((1.0 + math.pow((U_m / ((J + J) * t_2)), 2.0)))
	else:
		tmp = U_m
	return tmp
U_m = abs(U)
function code(J, K, U_m)
	t_0 = cos(Float64(K / 2.0))
	t_1 = Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J) * t_0)) ^ 2.0))))
	t_2 = cos(Float64(0.5 * K))
	tmp = 0.0
	if (t_1 <= Float64(-Inf))
		tmp = Float64(-U_m);
	elseif (t_1 <= 4e+306)
		tmp = Float64(Float64(Float64(-2.0 * J) * t_2) * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(J + J) * t_2)) ^ 2.0))));
	else
		tmp = U_m;
	end
	return tmp
end
U_m = abs(U);
function tmp_2 = code(J, K, U_m)
	t_0 = cos((K / 2.0));
	t_1 = ((-2.0 * J) * t_0) * sqrt((1.0 + ((U_m / ((2.0 * J) * t_0)) ^ 2.0)));
	t_2 = cos((0.5 * K));
	tmp = 0.0;
	if (t_1 <= -Inf)
		tmp = -U_m;
	elseif (t_1 <= 4e+306)
		tmp = ((-2.0 * J) * t_2) * sqrt((1.0 + ((U_m / ((J + J) * t_2)) ^ 2.0)));
	else
		tmp = U_m;
	end
	tmp_2 = tmp;
end
U_m = N[Abs[U], $MachinePrecision]
code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[Cos[N[(0.5 * K), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[t$95$1, (-Infinity)], (-U$95$m), If[LessEqual[t$95$1, 4e+306], N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$2), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(J + J), $MachinePrecision] * t$95$2), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], U$95$m]]]]]
\begin{array}{l}
U_m = \left|U\right|

\\
\begin{array}{l}
t_0 := \cos \left(\frac{K}{2}\right)\\
t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}}\\
t_2 := \cos \left(0.5 \cdot K\right)\\
\mathbf{if}\;t\_1 \leq -\infty:\\
\;\;\;\;-U\_m\\

\mathbf{elif}\;t\_1 \leq 4 \cdot 10^{+306}:\\
\;\;\;\;\left(\left(-2 \cdot J\right) \cdot t\_2\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(J + J\right) \cdot t\_2}\right)}^{2}}\\

\mathbf{else}:\\
\;\;\;\;U\_m\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -inf.0

    1. Initial program 5.6%

      \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    2. Taylor expanded in J around 0

      \[\leadsto \color{blue}{-1 \cdot U} \]
    3. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \mathsf{neg}\left(U\right) \]
      2. lower-neg.f6499.9

        \[\leadsto -U \]
    4. Applied rewrites99.9%

      \[\leadsto \color{blue}{-U} \]

    if -inf.0 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < 4.00000000000000007e306

    1. Initial program 99.8%

      \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    2. Taylor expanded in K around 0

      \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \color{blue}{\left(\frac{1}{2} \cdot K\right)}}\right)}^{2}} \]
    3. Step-by-step derivation
      1. lower-*.f6499.8

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(0.5 \cdot \color{blue}{K}\right)}\right)}^{2}} \]
    4. Applied rewrites99.8%

      \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \color{blue}{\left(0.5 \cdot K\right)}}\right)}^{2}} \]
    5. Taylor expanded in K around inf

      \[\leadsto \left(\left(-2 \cdot J\right) \cdot \color{blue}{\cos \left(\frac{1}{2} \cdot K\right)}\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)}\right)}^{2}} \]
    6. Step-by-step derivation
      1. lift-cos.f64N/A

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)}\right)}^{2}} \]
      2. lift-*.f6499.8

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(0.5 \cdot K\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(0.5 \cdot K\right)}\right)}^{2}} \]
    7. Applied rewrites99.8%

      \[\leadsto \left(\left(-2 \cdot J\right) \cdot \color{blue}{\cos \left(0.5 \cdot K\right)}\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(0.5 \cdot K\right)}\right)}^{2}} \]
    8. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{\left(2 \cdot J\right)} \cdot \cos \left(\frac{1}{2} \cdot K\right)}\right)}^{2}} \]
      2. count-2-revN/A

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{\left(J + J\right)} \cdot \cos \left(\frac{1}{2} \cdot K\right)}\right)}^{2}} \]
      3. lower-+.f6499.8

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(0.5 \cdot K\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{\left(J + J\right)} \cdot \cos \left(0.5 \cdot K\right)}\right)}^{2}} \]
    9. Applied rewrites99.8%

      \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(0.5 \cdot K\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{\left(J + J\right)} \cdot \cos \left(0.5 \cdot K\right)}\right)}^{2}} \]

    if 4.00000000000000007e306 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64)))))

    1. Initial program 6.5%

      \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    2. Taylor expanded in U around -inf

      \[\leadsto \color{blue}{U} \]
    3. Step-by-step derivation
      1. Applied rewrites99.3%

        \[\leadsto \color{blue}{U} \]
    4. Recombined 3 regimes into one program.
    5. Add Preprocessing

    Alternative 2: 81.6% accurate, 0.2× speedup?

    \[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(-2 \cdot J\right) \cdot t\_0\\ t_2 := t\_1 \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}}\\ t_3 := \left(J \cdot -2\right) \cdot \cos \left(0.5 \cdot K\right)\\ \mathbf{if}\;t\_2 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_2 \leq -2 \cdot 10^{+165}:\\ \;\;\;\;t\_3\\ \mathbf{elif}\;t\_2 \leq -2 \cdot 10^{-144}:\\ \;\;\;\;t\_1 \cdot \sqrt{\mathsf{fma}\left(\frac{U\_m \cdot U\_m}{J \cdot J}, 0.25, 1\right)}\\ \mathbf{elif}\;t\_2 \leq 4 \cdot 10^{+306}:\\ \;\;\;\;t\_3\\ \mathbf{else}:\\ \;\;\;\;U\_m\\ \end{array} \end{array} \]
    U_m = (fabs.f64 U)
    (FPCore (J K U_m)
     :precision binary64
     (let* ((t_0 (cos (/ K 2.0)))
            (t_1 (* (* -2.0 J) t_0))
            (t_2 (* t_1 (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J) t_0)) 2.0)))))
            (t_3 (* (* J -2.0) (cos (* 0.5 K)))))
       (if (<= t_2 (- INFINITY))
         (- U_m)
         (if (<= t_2 -2e+165)
           t_3
           (if (<= t_2 -2e-144)
             (* t_1 (sqrt (fma (/ (* U_m U_m) (* J J)) 0.25 1.0)))
             (if (<= t_2 4e+306) t_3 U_m))))))
    U_m = fabs(U);
    double code(double J, double K, double U_m) {
    	double t_0 = cos((K / 2.0));
    	double t_1 = (-2.0 * J) * t_0;
    	double t_2 = t_1 * sqrt((1.0 + pow((U_m / ((2.0 * J) * t_0)), 2.0)));
    	double t_3 = (J * -2.0) * cos((0.5 * K));
    	double tmp;
    	if (t_2 <= -((double) INFINITY)) {
    		tmp = -U_m;
    	} else if (t_2 <= -2e+165) {
    		tmp = t_3;
    	} else if (t_2 <= -2e-144) {
    		tmp = t_1 * sqrt(fma(((U_m * U_m) / (J * J)), 0.25, 1.0));
    	} else if (t_2 <= 4e+306) {
    		tmp = t_3;
    	} else {
    		tmp = U_m;
    	}
    	return tmp;
    }
    
    U_m = abs(U)
    function code(J, K, U_m)
    	t_0 = cos(Float64(K / 2.0))
    	t_1 = Float64(Float64(-2.0 * J) * t_0)
    	t_2 = Float64(t_1 * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J) * t_0)) ^ 2.0))))
    	t_3 = Float64(Float64(J * -2.0) * cos(Float64(0.5 * K)))
    	tmp = 0.0
    	if (t_2 <= Float64(-Inf))
    		tmp = Float64(-U_m);
    	elseif (t_2 <= -2e+165)
    		tmp = t_3;
    	elseif (t_2 <= -2e-144)
    		tmp = Float64(t_1 * sqrt(fma(Float64(Float64(U_m * U_m) / Float64(J * J)), 0.25, 1.0)));
    	elseif (t_2 <= 4e+306)
    		tmp = t_3;
    	else
    		tmp = U_m;
    	end
    	return tmp
    end
    
    U_m = N[Abs[U], $MachinePrecision]
    code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$1 * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(N[(J * -2.0), $MachinePrecision] * N[Cos[N[(0.5 * K), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$2, (-Infinity)], (-U$95$m), If[LessEqual[t$95$2, -2e+165], t$95$3, If[LessEqual[t$95$2, -2e-144], N[(t$95$1 * N[Sqrt[N[(N[(N[(U$95$m * U$95$m), $MachinePrecision] / N[(J * J), $MachinePrecision]), $MachinePrecision] * 0.25 + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$2, 4e+306], t$95$3, U$95$m]]]]]]]]
    
    \begin{array}{l}
    U_m = \left|U\right|
    
    \\
    \begin{array}{l}
    t_0 := \cos \left(\frac{K}{2}\right)\\
    t_1 := \left(-2 \cdot J\right) \cdot t\_0\\
    t_2 := t\_1 \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}}\\
    t_3 := \left(J \cdot -2\right) \cdot \cos \left(0.5 \cdot K\right)\\
    \mathbf{if}\;t\_2 \leq -\infty:\\
    \;\;\;\;-U\_m\\
    
    \mathbf{elif}\;t\_2 \leq -2 \cdot 10^{+165}:\\
    \;\;\;\;t\_3\\
    
    \mathbf{elif}\;t\_2 \leq -2 \cdot 10^{-144}:\\
    \;\;\;\;t\_1 \cdot \sqrt{\mathsf{fma}\left(\frac{U\_m \cdot U\_m}{J \cdot J}, 0.25, 1\right)}\\
    
    \mathbf{elif}\;t\_2 \leq 4 \cdot 10^{+306}:\\
    \;\;\;\;t\_3\\
    
    \mathbf{else}:\\
    \;\;\;\;U\_m\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 4 regimes
    2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -inf.0

      1. Initial program 5.6%

        \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      2. Taylor expanded in J around 0

        \[\leadsto \color{blue}{-1 \cdot U} \]
      3. Step-by-step derivation
        1. mul-1-negN/A

          \[\leadsto \mathsf{neg}\left(U\right) \]
        2. lower-neg.f6499.9

          \[\leadsto -U \]
      4. Applied rewrites99.9%

        \[\leadsto \color{blue}{-U} \]

      if -inf.0 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -1.9999999999999998e165 or -1.9999999999999999e-144 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < 4.00000000000000007e306

      1. Initial program 99.8%

        \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      2. Taylor expanded in J around inf

        \[\leadsto \color{blue}{-2 \cdot \left(J \cdot \cos \left(\frac{1}{2} \cdot K\right)\right)} \]
      3. Step-by-step derivation
        1. associate-*r*N/A

          \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\cos \left(\frac{1}{2} \cdot K\right)} \]
        2. lower-*.f64N/A

          \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\cos \left(\frac{1}{2} \cdot K\right)} \]
        3. *-commutativeN/A

          \[\leadsto \left(J \cdot -2\right) \cdot \cos \color{blue}{\left(\frac{1}{2} \cdot K\right)} \]
        4. lower-*.f64N/A

          \[\leadsto \left(J \cdot -2\right) \cdot \cos \color{blue}{\left(\frac{1}{2} \cdot K\right)} \]
        5. lower-cos.f64N/A

          \[\leadsto \left(J \cdot -2\right) \cdot \cos \left(\frac{1}{2} \cdot K\right) \]
        6. lower-*.f6471.1

          \[\leadsto \left(J \cdot -2\right) \cdot \cos \left(0.5 \cdot K\right) \]
      4. Applied rewrites71.1%

        \[\leadsto \color{blue}{\left(J \cdot -2\right) \cdot \cos \left(0.5 \cdot K\right)} \]

      if -1.9999999999999998e165 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -1.9999999999999999e-144

      1. Initial program 99.8%

        \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      2. Taylor expanded in K around 0

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
      3. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{\frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}} + \color{blue}{1}} \]
        2. *-commutativeN/A

          \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{\frac{{U}^{2}}{{J}^{2}} \cdot \frac{1}{4} + 1} \]
        3. lower-fma.f64N/A

          \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \color{blue}{\frac{1}{4}}, 1\right)} \]
        4. lower-/.f64N/A

          \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
        5. unpow2N/A

          \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
        6. lower-*.f64N/A

          \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
        7. unpow2N/A

          \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, \frac{1}{4}, 1\right)} \]
        8. lower-*.f6482.8

          \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)} \]
      4. Applied rewrites82.8%

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{\color{blue}{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)}} \]

      if 4.00000000000000007e306 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64)))))

      1. Initial program 6.5%

        \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      2. Taylor expanded in U around -inf

        \[\leadsto \color{blue}{U} \]
      3. Step-by-step derivation
        1. Applied rewrites99.3%

          \[\leadsto \color{blue}{U} \]
      4. Recombined 4 regimes into one program.
      5. Add Preprocessing

      Alternative 3: 77.6% accurate, 0.2× speedup?

      \[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}}\\ t_2 := \left(J \cdot -2\right) \cdot \cos \left(0.5 \cdot K\right)\\ \mathbf{if}\;t\_1 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_1 \leq -1 \cdot 10^{+151}:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq -4 \cdot 10^{-9}:\\ \;\;\;\;\left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U\_m \cdot U\_m}{J \cdot J}, 0.25, 1\right)}\\ \mathbf{elif}\;t\_1 \leq 4 \cdot 10^{+306}:\\ \;\;\;\;t\_2\\ \mathbf{else}:\\ \;\;\;\;U\_m\\ \end{array} \end{array} \]
      U_m = (fabs.f64 U)
      (FPCore (J K U_m)
       :precision binary64
       (let* ((t_0 (cos (/ K 2.0)))
              (t_1
               (*
                (* (* -2.0 J) t_0)
                (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J) t_0)) 2.0)))))
              (t_2 (* (* J -2.0) (cos (* 0.5 K)))))
         (if (<= t_1 (- INFINITY))
           (- U_m)
           (if (<= t_1 -1e+151)
             t_2
             (if (<= t_1 -4e-9)
               (* (* J -2.0) (sqrt (fma (/ (* U_m U_m) (* J J)) 0.25 1.0)))
               (if (<= t_1 4e+306) t_2 U_m))))))
      U_m = fabs(U);
      double code(double J, double K, double U_m) {
      	double t_0 = cos((K / 2.0));
      	double t_1 = ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U_m / ((2.0 * J) * t_0)), 2.0)));
      	double t_2 = (J * -2.0) * cos((0.5 * K));
      	double tmp;
      	if (t_1 <= -((double) INFINITY)) {
      		tmp = -U_m;
      	} else if (t_1 <= -1e+151) {
      		tmp = t_2;
      	} else if (t_1 <= -4e-9) {
      		tmp = (J * -2.0) * sqrt(fma(((U_m * U_m) / (J * J)), 0.25, 1.0));
      	} else if (t_1 <= 4e+306) {
      		tmp = t_2;
      	} else {
      		tmp = U_m;
      	}
      	return tmp;
      }
      
      U_m = abs(U)
      function code(J, K, U_m)
      	t_0 = cos(Float64(K / 2.0))
      	t_1 = Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J) * t_0)) ^ 2.0))))
      	t_2 = Float64(Float64(J * -2.0) * cos(Float64(0.5 * K)))
      	tmp = 0.0
      	if (t_1 <= Float64(-Inf))
      		tmp = Float64(-U_m);
      	elseif (t_1 <= -1e+151)
      		tmp = t_2;
      	elseif (t_1 <= -4e-9)
      		tmp = Float64(Float64(J * -2.0) * sqrt(fma(Float64(Float64(U_m * U_m) / Float64(J * J)), 0.25, 1.0)));
      	elseif (t_1 <= 4e+306)
      		tmp = t_2;
      	else
      		tmp = U_m;
      	end
      	return tmp
      end
      
      U_m = N[Abs[U], $MachinePrecision]
      code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(J * -2.0), $MachinePrecision] * N[Cos[N[(0.5 * K), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, (-Infinity)], (-U$95$m), If[LessEqual[t$95$1, -1e+151], t$95$2, If[LessEqual[t$95$1, -4e-9], N[(N[(J * -2.0), $MachinePrecision] * N[Sqrt[N[(N[(N[(U$95$m * U$95$m), $MachinePrecision] / N[(J * J), $MachinePrecision]), $MachinePrecision] * 0.25 + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$1, 4e+306], t$95$2, U$95$m]]]]]]]
      
      \begin{array}{l}
      U_m = \left|U\right|
      
      \\
      \begin{array}{l}
      t_0 := \cos \left(\frac{K}{2}\right)\\
      t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}}\\
      t_2 := \left(J \cdot -2\right) \cdot \cos \left(0.5 \cdot K\right)\\
      \mathbf{if}\;t\_1 \leq -\infty:\\
      \;\;\;\;-U\_m\\
      
      \mathbf{elif}\;t\_1 \leq -1 \cdot 10^{+151}:\\
      \;\;\;\;t\_2\\
      
      \mathbf{elif}\;t\_1 \leq -4 \cdot 10^{-9}:\\
      \;\;\;\;\left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U\_m \cdot U\_m}{J \cdot J}, 0.25, 1\right)}\\
      
      \mathbf{elif}\;t\_1 \leq 4 \cdot 10^{+306}:\\
      \;\;\;\;t\_2\\
      
      \mathbf{else}:\\
      \;\;\;\;U\_m\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 4 regimes
      2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -inf.0

        1. Initial program 5.6%

          \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        2. Taylor expanded in J around 0

          \[\leadsto \color{blue}{-1 \cdot U} \]
        3. Step-by-step derivation
          1. mul-1-negN/A

            \[\leadsto \mathsf{neg}\left(U\right) \]
          2. lower-neg.f6499.9

            \[\leadsto -U \]
        4. Applied rewrites99.9%

          \[\leadsto \color{blue}{-U} \]

        if -inf.0 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -1.00000000000000002e151 or -4.00000000000000025e-9 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < 4.00000000000000007e306

        1. Initial program 99.8%

          \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        2. Taylor expanded in J around inf

          \[\leadsto \color{blue}{-2 \cdot \left(J \cdot \cos \left(\frac{1}{2} \cdot K\right)\right)} \]
        3. Step-by-step derivation
          1. associate-*r*N/A

            \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\cos \left(\frac{1}{2} \cdot K\right)} \]
          2. lower-*.f64N/A

            \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\cos \left(\frac{1}{2} \cdot K\right)} \]
          3. *-commutativeN/A

            \[\leadsto \left(J \cdot -2\right) \cdot \cos \color{blue}{\left(\frac{1}{2} \cdot K\right)} \]
          4. lower-*.f64N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \cos \color{blue}{\left(\frac{1}{2} \cdot K\right)} \]
          5. lower-cos.f64N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \cos \left(\frac{1}{2} \cdot K\right) \]
          6. lower-*.f6470.5

            \[\leadsto \left(J \cdot -2\right) \cdot \cos \left(0.5 \cdot K\right) \]
        4. Applied rewrites70.5%

          \[\leadsto \color{blue}{\left(J \cdot -2\right) \cdot \cos \left(0.5 \cdot K\right)} \]

        if -1.00000000000000002e151 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -4.00000000000000025e-9

        1. Initial program 99.8%

          \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        2. Taylor expanded in K around 0

          \[\leadsto \color{blue}{-2 \cdot \left(J \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}\right)} \]
        3. Step-by-step derivation
          1. associate-*r*N/A

            \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
          2. lower-*.f64N/A

            \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
          3. *-commutativeN/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
          4. lower-*.f64N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
          5. lower-sqrt.f64N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}} \]
          6. +-commutativeN/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}} + 1} \]
          7. *-commutativeN/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{{U}^{2}}{{J}^{2}} \cdot \frac{1}{4} + 1} \]
          8. lower-fma.f64N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
          9. lower-/.f64N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
          10. unpow2N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
          11. lower-*.f64N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
          12. unpow2N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, \frac{1}{4}, 1\right)} \]
          13. lower-*.f6460.3

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)} \]
        4. Applied rewrites60.3%

          \[\leadsto \color{blue}{\left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)}} \]

        if 4.00000000000000007e306 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64)))))

        1. Initial program 6.5%

          \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        2. Taylor expanded in U around -inf

          \[\leadsto \color{blue}{U} \]
        3. Step-by-step derivation
          1. Applied rewrites99.3%

            \[\leadsto \color{blue}{U} \]
        4. Recombined 4 regimes into one program.
        5. Add Preprocessing

        Alternative 4: 57.1% accurate, 0.3× speedup?

        \[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}}\\ \mathbf{if}\;t\_1 \leq -2 \cdot 10^{+296}:\\ \;\;\;\;\mathsf{fma}\left(J \cdot \frac{J}{U\_m}, -2, -U\_m\right)\\ \mathbf{elif}\;t\_1 \leq -5 \cdot 10^{-158}:\\ \;\;\;\;\left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U\_m \cdot U\_m}{J \cdot J}, 0.25, 1\right)}\\ \mathbf{elif}\;t\_1 \leq -1 \cdot 10^{-232}:\\ \;\;\;\;-U\_m\\ \mathbf{else}:\\ \;\;\;\;U\_m\\ \end{array} \end{array} \]
        U_m = (fabs.f64 U)
        (FPCore (J K U_m)
         :precision binary64
         (let* ((t_0 (cos (/ K 2.0)))
                (t_1
                 (*
                  (* (* -2.0 J) t_0)
                  (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J) t_0)) 2.0))))))
           (if (<= t_1 -2e+296)
             (fma (* J (/ J U_m)) -2.0 (- U_m))
             (if (<= t_1 -5e-158)
               (* (* J -2.0) (sqrt (fma (/ (* U_m U_m) (* J J)) 0.25 1.0)))
               (if (<= t_1 -1e-232) (- U_m) U_m)))))
        U_m = fabs(U);
        double code(double J, double K, double U_m) {
        	double t_0 = cos((K / 2.0));
        	double t_1 = ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U_m / ((2.0 * J) * t_0)), 2.0)));
        	double tmp;
        	if (t_1 <= -2e+296) {
        		tmp = fma((J * (J / U_m)), -2.0, -U_m);
        	} else if (t_1 <= -5e-158) {
        		tmp = (J * -2.0) * sqrt(fma(((U_m * U_m) / (J * J)), 0.25, 1.0));
        	} else if (t_1 <= -1e-232) {
        		tmp = -U_m;
        	} else {
        		tmp = U_m;
        	}
        	return tmp;
        }
        
        U_m = abs(U)
        function code(J, K, U_m)
        	t_0 = cos(Float64(K / 2.0))
        	t_1 = Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J) * t_0)) ^ 2.0))))
        	tmp = 0.0
        	if (t_1 <= -2e+296)
        		tmp = fma(Float64(J * Float64(J / U_m)), -2.0, Float64(-U_m));
        	elseif (t_1 <= -5e-158)
        		tmp = Float64(Float64(J * -2.0) * sqrt(fma(Float64(Float64(U_m * U_m) / Float64(J * J)), 0.25, 1.0)));
        	elseif (t_1 <= -1e-232)
        		tmp = Float64(-U_m);
        	else
        		tmp = U_m;
        	end
        	return tmp
        end
        
        U_m = N[Abs[U], $MachinePrecision]
        code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, -2e+296], N[(N[(J * N[(J / U$95$m), $MachinePrecision]), $MachinePrecision] * -2.0 + (-U$95$m)), $MachinePrecision], If[LessEqual[t$95$1, -5e-158], N[(N[(J * -2.0), $MachinePrecision] * N[Sqrt[N[(N[(N[(U$95$m * U$95$m), $MachinePrecision] / N[(J * J), $MachinePrecision]), $MachinePrecision] * 0.25 + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$1, -1e-232], (-U$95$m), U$95$m]]]]]
        
        \begin{array}{l}
        U_m = \left|U\right|
        
        \\
        \begin{array}{l}
        t_0 := \cos \left(\frac{K}{2}\right)\\
        t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}}\\
        \mathbf{if}\;t\_1 \leq -2 \cdot 10^{+296}:\\
        \;\;\;\;\mathsf{fma}\left(J \cdot \frac{J}{U\_m}, -2, -U\_m\right)\\
        
        \mathbf{elif}\;t\_1 \leq -5 \cdot 10^{-158}:\\
        \;\;\;\;\left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U\_m \cdot U\_m}{J \cdot J}, 0.25, 1\right)}\\
        
        \mathbf{elif}\;t\_1 \leq -1 \cdot 10^{-232}:\\
        \;\;\;\;-U\_m\\
        
        \mathbf{else}:\\
        \;\;\;\;U\_m\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 4 regimes
        2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -1.99999999999999996e296

          1. Initial program 13.2%

            \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
          2. Taylor expanded in K around 0

            \[\leadsto \color{blue}{-2 \cdot \left(J \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}\right)} \]
          3. Step-by-step derivation
            1. associate-*r*N/A

              \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
            2. lower-*.f64N/A

              \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
            3. *-commutativeN/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
            4. lower-*.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
            5. lower-sqrt.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}} \]
            6. +-commutativeN/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}} + 1} \]
            7. *-commutativeN/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{{U}^{2}}{{J}^{2}} \cdot \frac{1}{4} + 1} \]
            8. lower-fma.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
            9. lower-/.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
            10. unpow2N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
            11. lower-*.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
            12. unpow2N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, \frac{1}{4}, 1\right)} \]
            13. lower-*.f646.7

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)} \]
          4. Applied rewrites6.7%

            \[\leadsto \color{blue}{\left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)}} \]
          5. Taylor expanded in J around 0

            \[\leadsto -2 \cdot \frac{{J}^{2}}{U} + \color{blue}{-1 \cdot U} \]
          6. Step-by-step derivation
            1. lower-fma.f64N/A

              \[\leadsto \mathsf{fma}\left(-2, \frac{{J}^{2}}{\color{blue}{U}}, -1 \cdot U\right) \]
            2. lower-/.f64N/A

              \[\leadsto \mathsf{fma}\left(-2, \frac{{J}^{2}}{U}, -1 \cdot U\right) \]
            3. pow2N/A

              \[\leadsto \mathsf{fma}\left(-2, \frac{J \cdot J}{U}, -1 \cdot U\right) \]
            4. lift-*.f64N/A

              \[\leadsto \mathsf{fma}\left(-2, \frac{J \cdot J}{U}, -1 \cdot U\right) \]
            5. lower-*.f6493.0

              \[\leadsto \mathsf{fma}\left(-2, \frac{J \cdot J}{U}, -1 \cdot U\right) \]
          7. Applied rewrites93.0%

            \[\leadsto \mathsf{fma}\left(-2, \color{blue}{\frac{J \cdot J}{U}}, -1 \cdot U\right) \]
          8. Step-by-step derivation
            1. lift-*.f64N/A

              \[\leadsto \mathsf{fma}\left(-2, \frac{J \cdot J}{U}, -1 \cdot U\right) \]
            2. lift-fma.f64N/A

              \[\leadsto -2 \cdot \frac{J \cdot J}{U} + -1 \cdot \color{blue}{U} \]
            3. *-commutativeN/A

              \[\leadsto \frac{J \cdot J}{U} \cdot -2 + -1 \cdot U \]
            4. lower-fma.f64N/A

              \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, -2, -1 \cdot U\right) \]
            5. lift-*.f64N/A

              \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, -2, -1 \cdot U\right) \]
            6. lift-/.f64N/A

              \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, -2, -1 \cdot U\right) \]
            7. associate-/l*N/A

              \[\leadsto \mathsf{fma}\left(J \cdot \frac{J}{U}, -2, -1 \cdot U\right) \]
            8. lower-*.f64N/A

              \[\leadsto \mathsf{fma}\left(J \cdot \frac{J}{U}, -2, -1 \cdot U\right) \]
            9. lower-/.f64N/A

              \[\leadsto \mathsf{fma}\left(J \cdot \frac{J}{U}, -2, -1 \cdot U\right) \]
            10. mul-1-negN/A

              \[\leadsto \mathsf{fma}\left(J \cdot \frac{J}{U}, -2, \mathsf{neg}\left(U\right)\right) \]
            11. lower-neg.f6494.5

              \[\leadsto \mathsf{fma}\left(J \cdot \frac{J}{U}, -2, -U\right) \]
          9. Applied rewrites94.5%

            \[\leadsto \color{blue}{\mathsf{fma}\left(J \cdot \frac{J}{U}, -2, -U\right)} \]

          if -1.99999999999999996e296 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -4.99999999999999972e-158

          1. Initial program 99.8%

            \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
          2. Taylor expanded in K around 0

            \[\leadsto \color{blue}{-2 \cdot \left(J \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}\right)} \]
          3. Step-by-step derivation
            1. associate-*r*N/A

              \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
            2. lower-*.f64N/A

              \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
            3. *-commutativeN/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
            4. lower-*.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
            5. lower-sqrt.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}} \]
            6. +-commutativeN/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}} + 1} \]
            7. *-commutativeN/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{{U}^{2}}{{J}^{2}} \cdot \frac{1}{4} + 1} \]
            8. lower-fma.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
            9. lower-/.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
            10. unpow2N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
            11. lower-*.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
            12. unpow2N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, \frac{1}{4}, 1\right)} \]
            13. lower-*.f6447.7

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)} \]
          4. Applied rewrites47.7%

            \[\leadsto \color{blue}{\left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)}} \]

          if -4.99999999999999972e-158 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -1.00000000000000002e-232

          1. Initial program 99.8%

            \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
          2. Taylor expanded in J around 0

            \[\leadsto \color{blue}{-1 \cdot U} \]
          3. Step-by-step derivation
            1. mul-1-negN/A

              \[\leadsto \mathsf{neg}\left(U\right) \]
            2. lower-neg.f6454.1

              \[\leadsto -U \]
          4. Applied rewrites54.1%

            \[\leadsto \color{blue}{-U} \]

          if -1.00000000000000002e-232 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64)))))

          1. Initial program 73.0%

            \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
          2. Taylor expanded in U around -inf

            \[\leadsto \color{blue}{U} \]
          3. Step-by-step derivation
            1. Applied rewrites51.9%

              \[\leadsto \color{blue}{U} \]
          4. Recombined 4 regimes into one program.
          5. Add Preprocessing

          Alternative 5: 90.9% accurate, 0.4× speedup?

          \[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(-2 \cdot J\right) \cdot t\_0\\ t_2 := t\_1 \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}}\\ \mathbf{if}\;t\_2 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_2 \leq 4 \cdot 10^{+306}:\\ \;\;\;\;t\_1 \cdot \sqrt{1 + 0.25 \cdot \left(\frac{U\_m}{J} \cdot \frac{U\_m}{J}\right)}\\ \mathbf{else}:\\ \;\;\;\;U\_m\\ \end{array} \end{array} \]
          U_m = (fabs.f64 U)
          (FPCore (J K U_m)
           :precision binary64
           (let* ((t_0 (cos (/ K 2.0)))
                  (t_1 (* (* -2.0 J) t_0))
                  (t_2 (* t_1 (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J) t_0)) 2.0))))))
             (if (<= t_2 (- INFINITY))
               (- U_m)
               (if (<= t_2 4e+306)
                 (* t_1 (sqrt (+ 1.0 (* 0.25 (* (/ U_m J) (/ U_m J))))))
                 U_m))))
          U_m = fabs(U);
          double code(double J, double K, double U_m) {
          	double t_0 = cos((K / 2.0));
          	double t_1 = (-2.0 * J) * t_0;
          	double t_2 = t_1 * sqrt((1.0 + pow((U_m / ((2.0 * J) * t_0)), 2.0)));
          	double tmp;
          	if (t_2 <= -((double) INFINITY)) {
          		tmp = -U_m;
          	} else if (t_2 <= 4e+306) {
          		tmp = t_1 * sqrt((1.0 + (0.25 * ((U_m / J) * (U_m / J)))));
          	} else {
          		tmp = U_m;
          	}
          	return tmp;
          }
          
          U_m = Math.abs(U);
          public static double code(double J, double K, double U_m) {
          	double t_0 = Math.cos((K / 2.0));
          	double t_1 = (-2.0 * J) * t_0;
          	double t_2 = t_1 * Math.sqrt((1.0 + Math.pow((U_m / ((2.0 * J) * t_0)), 2.0)));
          	double tmp;
          	if (t_2 <= -Double.POSITIVE_INFINITY) {
          		tmp = -U_m;
          	} else if (t_2 <= 4e+306) {
          		tmp = t_1 * Math.sqrt((1.0 + (0.25 * ((U_m / J) * (U_m / J)))));
          	} else {
          		tmp = U_m;
          	}
          	return tmp;
          }
          
          U_m = math.fabs(U)
          def code(J, K, U_m):
          	t_0 = math.cos((K / 2.0))
          	t_1 = (-2.0 * J) * t_0
          	t_2 = t_1 * math.sqrt((1.0 + math.pow((U_m / ((2.0 * J) * t_0)), 2.0)))
          	tmp = 0
          	if t_2 <= -math.inf:
          		tmp = -U_m
          	elif t_2 <= 4e+306:
          		tmp = t_1 * math.sqrt((1.0 + (0.25 * ((U_m / J) * (U_m / J)))))
          	else:
          		tmp = U_m
          	return tmp
          
          U_m = abs(U)
          function code(J, K, U_m)
          	t_0 = cos(Float64(K / 2.0))
          	t_1 = Float64(Float64(-2.0 * J) * t_0)
          	t_2 = Float64(t_1 * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J) * t_0)) ^ 2.0))))
          	tmp = 0.0
          	if (t_2 <= Float64(-Inf))
          		tmp = Float64(-U_m);
          	elseif (t_2 <= 4e+306)
          		tmp = Float64(t_1 * sqrt(Float64(1.0 + Float64(0.25 * Float64(Float64(U_m / J) * Float64(U_m / J))))));
          	else
          		tmp = U_m;
          	end
          	return tmp
          end
          
          U_m = abs(U);
          function tmp_2 = code(J, K, U_m)
          	t_0 = cos((K / 2.0));
          	t_1 = (-2.0 * J) * t_0;
          	t_2 = t_1 * sqrt((1.0 + ((U_m / ((2.0 * J) * t_0)) ^ 2.0)));
          	tmp = 0.0;
          	if (t_2 <= -Inf)
          		tmp = -U_m;
          	elseif (t_2 <= 4e+306)
          		tmp = t_1 * sqrt((1.0 + (0.25 * ((U_m / J) * (U_m / J)))));
          	else
          		tmp = U_m;
          	end
          	tmp_2 = tmp;
          end
          
          U_m = N[Abs[U], $MachinePrecision]
          code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$1 * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$2, (-Infinity)], (-U$95$m), If[LessEqual[t$95$2, 4e+306], N[(t$95$1 * N[Sqrt[N[(1.0 + N[(0.25 * N[(N[(U$95$m / J), $MachinePrecision] * N[(U$95$m / J), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], U$95$m]]]]]
          
          \begin{array}{l}
          U_m = \left|U\right|
          
          \\
          \begin{array}{l}
          t_0 := \cos \left(\frac{K}{2}\right)\\
          t_1 := \left(-2 \cdot J\right) \cdot t\_0\\
          t_2 := t\_1 \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}}\\
          \mathbf{if}\;t\_2 \leq -\infty:\\
          \;\;\;\;-U\_m\\
          
          \mathbf{elif}\;t\_2 \leq 4 \cdot 10^{+306}:\\
          \;\;\;\;t\_1 \cdot \sqrt{1 + 0.25 \cdot \left(\frac{U\_m}{J} \cdot \frac{U\_m}{J}\right)}\\
          
          \mathbf{else}:\\
          \;\;\;\;U\_m\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 3 regimes
          2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -inf.0

            1. Initial program 5.6%

              \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
            2. Taylor expanded in J around 0

              \[\leadsto \color{blue}{-1 \cdot U} \]
            3. Step-by-step derivation
              1. mul-1-negN/A

                \[\leadsto \mathsf{neg}\left(U\right) \]
              2. lower-neg.f6499.9

                \[\leadsto -U \]
            4. Applied rewrites99.9%

              \[\leadsto \color{blue}{-U} \]

            if -inf.0 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < 4.00000000000000007e306

            1. Initial program 99.8%

              \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
            2. Taylor expanded in K around 0

              \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \color{blue}{\left(\frac{1}{2} \cdot K\right)}}\right)}^{2}} \]
            3. Step-by-step derivation
              1. lower-*.f6499.8

                \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(0.5 \cdot \color{blue}{K}\right)}\right)}^{2}} \]
            4. Applied rewrites99.8%

              \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \color{blue}{\left(0.5 \cdot K\right)}}\right)}^{2}} \]
            5. Taylor expanded in K around 0

              \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + \color{blue}{\frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
            6. Step-by-step derivation
              1. lower-*.f64N/A

                \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + \frac{1}{4} \cdot \color{blue}{\frac{{U}^{2}}{{J}^{2}}}} \]
              2. pow2N/A

                \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{U \cdot U}{{\color{blue}{J}}^{2}}} \]
              3. pow2N/A

                \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{U \cdot U}{J \cdot \color{blue}{J}}} \]
              4. times-fracN/A

                \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + \frac{1}{4} \cdot \left(\frac{U}{J} \cdot \color{blue}{\frac{U}{J}}\right)} \]
              5. lower-*.f64N/A

                \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + \frac{1}{4} \cdot \left(\frac{U}{J} \cdot \color{blue}{\frac{U}{J}}\right)} \]
              6. lower-/.f64N/A

                \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + \frac{1}{4} \cdot \left(\frac{U}{J} \cdot \frac{\color{blue}{U}}{J}\right)} \]
              7. lower-/.f6487.5

                \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + 0.25 \cdot \left(\frac{U}{J} \cdot \frac{U}{\color{blue}{J}}\right)} \]
            7. Applied rewrites87.5%

              \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + \color{blue}{0.25 \cdot \left(\frac{U}{J} \cdot \frac{U}{J}\right)}} \]

            if 4.00000000000000007e306 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64)))))

            1. Initial program 6.5%

              \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
            2. Taylor expanded in U around -inf

              \[\leadsto \color{blue}{U} \]
            3. Step-by-step derivation
              1. Applied rewrites99.3%

                \[\leadsto \color{blue}{U} \]
            4. Recombined 3 regimes into one program.
            5. Add Preprocessing

            Alternative 6: 54.3% accurate, 0.5× speedup?

            \[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}}\\ \mathbf{if}\;t\_1 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_1 \leq -1 \cdot 10^{-232}:\\ \;\;\;\;-2 \cdot J\\ \mathbf{else}:\\ \;\;\;\;U\_m\\ \end{array} \end{array} \]
            U_m = (fabs.f64 U)
            (FPCore (J K U_m)
             :precision binary64
             (let* ((t_0 (cos (/ K 2.0)))
                    (t_1
                     (*
                      (* (* -2.0 J) t_0)
                      (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J) t_0)) 2.0))))))
               (if (<= t_1 (- INFINITY)) (- U_m) (if (<= t_1 -1e-232) (* -2.0 J) U_m))))
            U_m = fabs(U);
            double code(double J, double K, double U_m) {
            	double t_0 = cos((K / 2.0));
            	double t_1 = ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U_m / ((2.0 * J) * t_0)), 2.0)));
            	double tmp;
            	if (t_1 <= -((double) INFINITY)) {
            		tmp = -U_m;
            	} else if (t_1 <= -1e-232) {
            		tmp = -2.0 * J;
            	} else {
            		tmp = U_m;
            	}
            	return tmp;
            }
            
            U_m = Math.abs(U);
            public static double code(double J, double K, double U_m) {
            	double t_0 = Math.cos((K / 2.0));
            	double t_1 = ((-2.0 * J) * t_0) * Math.sqrt((1.0 + Math.pow((U_m / ((2.0 * J) * t_0)), 2.0)));
            	double tmp;
            	if (t_1 <= -Double.POSITIVE_INFINITY) {
            		tmp = -U_m;
            	} else if (t_1 <= -1e-232) {
            		tmp = -2.0 * J;
            	} else {
            		tmp = U_m;
            	}
            	return tmp;
            }
            
            U_m = math.fabs(U)
            def code(J, K, U_m):
            	t_0 = math.cos((K / 2.0))
            	t_1 = ((-2.0 * J) * t_0) * math.sqrt((1.0 + math.pow((U_m / ((2.0 * J) * t_0)), 2.0)))
            	tmp = 0
            	if t_1 <= -math.inf:
            		tmp = -U_m
            	elif t_1 <= -1e-232:
            		tmp = -2.0 * J
            	else:
            		tmp = U_m
            	return tmp
            
            U_m = abs(U)
            function code(J, K, U_m)
            	t_0 = cos(Float64(K / 2.0))
            	t_1 = Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J) * t_0)) ^ 2.0))))
            	tmp = 0.0
            	if (t_1 <= Float64(-Inf))
            		tmp = Float64(-U_m);
            	elseif (t_1 <= -1e-232)
            		tmp = Float64(-2.0 * J);
            	else
            		tmp = U_m;
            	end
            	return tmp
            end
            
            U_m = abs(U);
            function tmp_2 = code(J, K, U_m)
            	t_0 = cos((K / 2.0));
            	t_1 = ((-2.0 * J) * t_0) * sqrt((1.0 + ((U_m / ((2.0 * J) * t_0)) ^ 2.0)));
            	tmp = 0.0;
            	if (t_1 <= -Inf)
            		tmp = -U_m;
            	elseif (t_1 <= -1e-232)
            		tmp = -2.0 * J;
            	else
            		tmp = U_m;
            	end
            	tmp_2 = tmp;
            end
            
            U_m = N[Abs[U], $MachinePrecision]
            code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, (-Infinity)], (-U$95$m), If[LessEqual[t$95$1, -1e-232], N[(-2.0 * J), $MachinePrecision], U$95$m]]]]
            
            \begin{array}{l}
            U_m = \left|U\right|
            
            \\
            \begin{array}{l}
            t_0 := \cos \left(\frac{K}{2}\right)\\
            t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}}\\
            \mathbf{if}\;t\_1 \leq -\infty:\\
            \;\;\;\;-U\_m\\
            
            \mathbf{elif}\;t\_1 \leq -1 \cdot 10^{-232}:\\
            \;\;\;\;-2 \cdot J\\
            
            \mathbf{else}:\\
            \;\;\;\;U\_m\\
            
            
            \end{array}
            \end{array}
            
            Derivation
            1. Split input into 3 regimes
            2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -inf.0

              1. Initial program 5.6%

                \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
              2. Taylor expanded in J around 0

                \[\leadsto \color{blue}{-1 \cdot U} \]
              3. Step-by-step derivation
                1. mul-1-negN/A

                  \[\leadsto \mathsf{neg}\left(U\right) \]
                2. lower-neg.f6499.9

                  \[\leadsto -U \]
              4. Applied rewrites99.9%

                \[\leadsto \color{blue}{-U} \]

              if -inf.0 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -1.00000000000000002e-232

              1. Initial program 99.8%

                \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
              2. Taylor expanded in J around inf

                \[\leadsto \color{blue}{-2 \cdot \left(J \cdot \cos \left(\frac{1}{2} \cdot K\right)\right)} \]
              3. Step-by-step derivation
                1. associate-*r*N/A

                  \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\cos \left(\frac{1}{2} \cdot K\right)} \]
                2. lower-*.f64N/A

                  \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\cos \left(\frac{1}{2} \cdot K\right)} \]
                3. *-commutativeN/A

                  \[\leadsto \left(J \cdot -2\right) \cdot \cos \color{blue}{\left(\frac{1}{2} \cdot K\right)} \]
                4. lower-*.f64N/A

                  \[\leadsto \left(J \cdot -2\right) \cdot \cos \color{blue}{\left(\frac{1}{2} \cdot K\right)} \]
                5. lower-cos.f64N/A

                  \[\leadsto \left(J \cdot -2\right) \cdot \cos \left(\frac{1}{2} \cdot K\right) \]
                6. lower-*.f6471.2

                  \[\leadsto \left(J \cdot -2\right) \cdot \cos \left(0.5 \cdot K\right) \]
              4. Applied rewrites71.2%

                \[\leadsto \color{blue}{\left(J \cdot -2\right) \cdot \cos \left(0.5 \cdot K\right)} \]
              5. Taylor expanded in K around 0

                \[\leadsto -2 \cdot \color{blue}{J} \]
              6. Step-by-step derivation
                1. lift-*.f6439.7

                  \[\leadsto -2 \cdot J \]
              7. Applied rewrites39.7%

                \[\leadsto -2 \cdot \color{blue}{J} \]

              if -1.00000000000000002e-232 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64)))))

              1. Initial program 73.0%

                \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
              2. Taylor expanded in U around -inf

                \[\leadsto \color{blue}{U} \]
              3. Step-by-step derivation
                1. Applied rewrites51.9%

                  \[\leadsto \color{blue}{U} \]
              4. Recombined 3 regimes into one program.
              5. Add Preprocessing

              Alternative 7: 51.8% accurate, 1.0× speedup?

              \[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ \mathbf{if}\;\left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}} \leq -1 \cdot 10^{-232}:\\ \;\;\;\;-U\_m\\ \mathbf{else}:\\ \;\;\;\;U\_m\\ \end{array} \end{array} \]
              U_m = (fabs.f64 U)
              (FPCore (J K U_m)
               :precision binary64
               (let* ((t_0 (cos (/ K 2.0))))
                 (if (<=
                      (*
                       (* (* -2.0 J) t_0)
                       (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J) t_0)) 2.0))))
                      -1e-232)
                   (- U_m)
                   U_m)))
              U_m = fabs(U);
              double code(double J, double K, double U_m) {
              	double t_0 = cos((K / 2.0));
              	double tmp;
              	if ((((-2.0 * J) * t_0) * sqrt((1.0 + pow((U_m / ((2.0 * J) * t_0)), 2.0)))) <= -1e-232) {
              		tmp = -U_m;
              	} else {
              		tmp = U_m;
              	}
              	return tmp;
              }
              
              U_m =     private
              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(j, k, u_m)
              use fmin_fmax_functions
                  real(8), intent (in) :: j
                  real(8), intent (in) :: k
                  real(8), intent (in) :: u_m
                  real(8) :: t_0
                  real(8) :: tmp
                  t_0 = cos((k / 2.0d0))
                  if (((((-2.0d0) * j) * t_0) * sqrt((1.0d0 + ((u_m / ((2.0d0 * j) * t_0)) ** 2.0d0)))) <= (-1d-232)) then
                      tmp = -u_m
                  else
                      tmp = u_m
                  end if
                  code = tmp
              end function
              
              U_m = Math.abs(U);
              public static double code(double J, double K, double U_m) {
              	double t_0 = Math.cos((K / 2.0));
              	double tmp;
              	if ((((-2.0 * J) * t_0) * Math.sqrt((1.0 + Math.pow((U_m / ((2.0 * J) * t_0)), 2.0)))) <= -1e-232) {
              		tmp = -U_m;
              	} else {
              		tmp = U_m;
              	}
              	return tmp;
              }
              
              U_m = math.fabs(U)
              def code(J, K, U_m):
              	t_0 = math.cos((K / 2.0))
              	tmp = 0
              	if (((-2.0 * J) * t_0) * math.sqrt((1.0 + math.pow((U_m / ((2.0 * J) * t_0)), 2.0)))) <= -1e-232:
              		tmp = -U_m
              	else:
              		tmp = U_m
              	return tmp
              
              U_m = abs(U)
              function code(J, K, U_m)
              	t_0 = cos(Float64(K / 2.0))
              	tmp = 0.0
              	if (Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J) * t_0)) ^ 2.0)))) <= -1e-232)
              		tmp = Float64(-U_m);
              	else
              		tmp = U_m;
              	end
              	return tmp
              end
              
              U_m = abs(U);
              function tmp_2 = code(J, K, U_m)
              	t_0 = cos((K / 2.0));
              	tmp = 0.0;
              	if ((((-2.0 * J) * t_0) * sqrt((1.0 + ((U_m / ((2.0 * J) * t_0)) ^ 2.0)))) <= -1e-232)
              		tmp = -U_m;
              	else
              		tmp = U_m;
              	end
              	tmp_2 = tmp;
              end
              
              U_m = N[Abs[U], $MachinePrecision]
              code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], -1e-232], (-U$95$m), U$95$m]]
              
              \begin{array}{l}
              U_m = \left|U\right|
              
              \\
              \begin{array}{l}
              t_0 := \cos \left(\frac{K}{2}\right)\\
              \mathbf{if}\;\left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}} \leq -1 \cdot 10^{-232}:\\
              \;\;\;\;-U\_m\\
              
              \mathbf{else}:\\
              \;\;\;\;U\_m\\
              
              
              \end{array}
              \end{array}
              
              Derivation
              1. Split input into 2 regimes
              2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -1.00000000000000002e-232

                1. Initial program 73.4%

                  \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
                2. Taylor expanded in J around 0

                  \[\leadsto \color{blue}{-1 \cdot U} \]
                3. Step-by-step derivation
                  1. mul-1-negN/A

                    \[\leadsto \mathsf{neg}\left(U\right) \]
                  2. lower-neg.f6451.7

                    \[\leadsto -U \]
                4. Applied rewrites51.7%

                  \[\leadsto \color{blue}{-U} \]

                if -1.00000000000000002e-232 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64)))))

                1. Initial program 73.0%

                  \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
                2. Taylor expanded in U around -inf

                  \[\leadsto \color{blue}{U} \]
                3. Step-by-step derivation
                  1. Applied rewrites51.9%

                    \[\leadsto \color{blue}{U} \]
                4. Recombined 2 regimes into one program.
                5. Add Preprocessing

                Alternative 8: 26.5% accurate, 373.0× speedup?

                \[\begin{array}{l} U_m = \left|U\right| \\ U\_m \end{array} \]
                U_m = (fabs.f64 U)
                (FPCore (J K U_m) :precision binary64 U_m)
                U_m = fabs(U);
                double code(double J, double K, double U_m) {
                	return U_m;
                }
                
                U_m =     private
                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(j, k, u_m)
                use fmin_fmax_functions
                    real(8), intent (in) :: j
                    real(8), intent (in) :: k
                    real(8), intent (in) :: u_m
                    code = u_m
                end function
                
                U_m = Math.abs(U);
                public static double code(double J, double K, double U_m) {
                	return U_m;
                }
                
                U_m = math.fabs(U)
                def code(J, K, U_m):
                	return U_m
                
                U_m = abs(U)
                function code(J, K, U_m)
                	return U_m
                end
                
                U_m = abs(U);
                function tmp = code(J, K, U_m)
                	tmp = U_m;
                end
                
                U_m = N[Abs[U], $MachinePrecision]
                code[J_, K_, U$95$m_] := U$95$m
                
                \begin{array}{l}
                U_m = \left|U\right|
                
                \\
                U\_m
                \end{array}
                
                Derivation
                1. Initial program 73.2%

                  \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
                2. Taylor expanded in U around -inf

                  \[\leadsto \color{blue}{U} \]
                3. Step-by-step derivation
                  1. Applied rewrites26.5%

                    \[\leadsto \color{blue}{U} \]
                  2. Add Preprocessing

                  Reproduce

                  ?
                  herbie shell --seed 2025100 
                  (FPCore (J K U)
                    :name "Maksimov and Kolovsky, Equation (3)"
                    :precision binary64
                    (* (* (* -2.0 J) (cos (/ K 2.0))) (sqrt (+ 1.0 (pow (/ U (* (* 2.0 J) (cos (/ K 2.0)))) 2.0)))))