Maksimov and Kolovsky, Equation (3)

Percentage Accurate: 72.2% → 99.1%
Time: 9.4s
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}

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 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: 72.2% 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: 99.1% accurate, 0.3× speedup?

\[\begin{array}{l} U_m = \left|U\right| \\ J\_m = \left|J\right| \\ J\_s = \mathsf{copysign}\left(1, J\right) \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(-2 \cdot J\_m\right) \cdot t\_0\\ t_2 := t\_1 \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\_m\right) \cdot t\_0}\right)}^{2}}\\ J\_s \cdot \begin{array}{l} \mathbf{if}\;t\_2 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_2 \leq 4 \cdot 10^{+288}:\\ \;\;\;\;t\_1 \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\_m\right) \cdot \cos \left(-0.5 \cdot K\right)}\right)}^{2}}\\ \mathbf{else}:\\ \;\;\;\;-1 \cdot \left(-U\_m\right)\\ \end{array} \end{array} \end{array} \]
U_m = (fabs.f64 U)
J\_m = (fabs.f64 J)
J\_s = (copysign.f64 #s(literal 1 binary64) J)
(FPCore (J_s J_m K U_m)
 :precision binary64
 (let* ((t_0 (cos (/ K 2.0)))
        (t_1 (* (* -2.0 J_m) t_0))
        (t_2 (* t_1 (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J_m) t_0)) 2.0))))))
   (*
    J_s
    (if (<= t_2 (- INFINITY))
      (- U_m)
      (if (<= t_2 4e+288)
        (*
         t_1
         (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J_m) (cos (* -0.5 K)))) 2.0))))
        (* -1.0 (- U_m)))))))
U_m = fabs(U);
J\_m = fabs(J);
J\_s = copysign(1.0, J);
double code(double J_s, double J_m, double K, double U_m) {
	double t_0 = cos((K / 2.0));
	double t_1 = (-2.0 * J_m) * t_0;
	double t_2 = t_1 * sqrt((1.0 + pow((U_m / ((2.0 * J_m) * t_0)), 2.0)));
	double tmp;
	if (t_2 <= -((double) INFINITY)) {
		tmp = -U_m;
	} else if (t_2 <= 4e+288) {
		tmp = t_1 * sqrt((1.0 + pow((U_m / ((2.0 * J_m) * cos((-0.5 * K)))), 2.0)));
	} else {
		tmp = -1.0 * -U_m;
	}
	return J_s * tmp;
}
U_m = Math.abs(U);
J\_m = Math.abs(J);
J\_s = Math.copySign(1.0, J);
public static double code(double J_s, double J_m, double K, double U_m) {
	double t_0 = Math.cos((K / 2.0));
	double t_1 = (-2.0 * J_m) * t_0;
	double t_2 = t_1 * Math.sqrt((1.0 + Math.pow((U_m / ((2.0 * J_m) * t_0)), 2.0)));
	double tmp;
	if (t_2 <= -Double.POSITIVE_INFINITY) {
		tmp = -U_m;
	} else if (t_2 <= 4e+288) {
		tmp = t_1 * Math.sqrt((1.0 + Math.pow((U_m / ((2.0 * J_m) * Math.cos((-0.5 * K)))), 2.0)));
	} else {
		tmp = -1.0 * -U_m;
	}
	return J_s * tmp;
}
U_m = math.fabs(U)
J\_m = math.fabs(J)
J\_s = math.copysign(1.0, J)
def code(J_s, J_m, K, U_m):
	t_0 = math.cos((K / 2.0))
	t_1 = (-2.0 * J_m) * t_0
	t_2 = t_1 * math.sqrt((1.0 + math.pow((U_m / ((2.0 * J_m) * t_0)), 2.0)))
	tmp = 0
	if t_2 <= -math.inf:
		tmp = -U_m
	elif t_2 <= 4e+288:
		tmp = t_1 * math.sqrt((1.0 + math.pow((U_m / ((2.0 * J_m) * math.cos((-0.5 * K)))), 2.0)))
	else:
		tmp = -1.0 * -U_m
	return J_s * tmp
U_m = abs(U)
J\_m = abs(J)
J\_s = copysign(1.0, J)
function code(J_s, J_m, K, U_m)
	t_0 = cos(Float64(K / 2.0))
	t_1 = Float64(Float64(-2.0 * J_m) * t_0)
	t_2 = Float64(t_1 * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J_m) * t_0)) ^ 2.0))))
	tmp = 0.0
	if (t_2 <= Float64(-Inf))
		tmp = Float64(-U_m);
	elseif (t_2 <= 4e+288)
		tmp = Float64(t_1 * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J_m) * cos(Float64(-0.5 * K)))) ^ 2.0))));
	else
		tmp = Float64(-1.0 * Float64(-U_m));
	end
	return Float64(J_s * tmp)
end
U_m = abs(U);
J\_m = abs(J);
J\_s = sign(J) * abs(1.0);
function tmp_2 = code(J_s, J_m, K, U_m)
	t_0 = cos((K / 2.0));
	t_1 = (-2.0 * J_m) * t_0;
	t_2 = t_1 * sqrt((1.0 + ((U_m / ((2.0 * J_m) * t_0)) ^ 2.0)));
	tmp = 0.0;
	if (t_2 <= -Inf)
		tmp = -U_m;
	elseif (t_2 <= 4e+288)
		tmp = t_1 * sqrt((1.0 + ((U_m / ((2.0 * J_m) * cos((-0.5 * K)))) ^ 2.0)));
	else
		tmp = -1.0 * -U_m;
	end
	tmp_2 = J_s * tmp;
end
U_m = N[Abs[U], $MachinePrecision]
J\_m = N[Abs[J], $MachinePrecision]
J\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[J]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[J$95$s_, J$95$m_, 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$95$m), $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$95$m), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, N[(J$95$s * If[LessEqual[t$95$2, (-Infinity)], (-U$95$m), If[LessEqual[t$95$2, 4e+288], N[(t$95$1 * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(2.0 * J$95$m), $MachinePrecision] * N[Cos[N[(-0.5 * K), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(-1.0 * (-U$95$m)), $MachinePrecision]]]), $MachinePrecision]]]]
\begin{array}{l}
U_m = \left|U\right|
\\
J\_m = \left|J\right|
\\
J\_s = \mathsf{copysign}\left(1, J\right)

\\
\begin{array}{l}
t_0 := \cos \left(\frac{K}{2}\right)\\
t_1 := \left(-2 \cdot J\_m\right) \cdot t\_0\\
t_2 := t\_1 \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\_m\right) \cdot t\_0}\right)}^{2}}\\
J\_s \cdot \begin{array}{l}
\mathbf{if}\;t\_2 \leq -\infty:\\
\;\;\;\;-U\_m\\

\mathbf{elif}\;t\_2 \leq 4 \cdot 10^{+288}:\\
\;\;\;\;t\_1 \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\_m\right) \cdot \cos \left(-0.5 \cdot K\right)}\right)}^{2}}\\

\mathbf{else}:\\
\;\;\;\;-1 \cdot \left(-U\_m\right)\\


\end{array}
\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 4.7%

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

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

        \[\leadsto \color{blue}{\mathsf{neg}\left(U\right)} \]
      2. lower-neg.f6463.3

        \[\leadsto \color{blue}{-U} \]
    5. Applied rewrites63.3%

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

    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))))) < 4e288

    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. Add Preprocessing
    3. Taylor expanded in K around inf

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

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

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

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

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

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

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

    if 4e288 < (*.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 18.3%

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

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

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

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

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

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\color{blue}{\frac{-1}{2}} \cdot K\right)}\right)}^{2}} \]
      5. lower-*.f6418.3

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \color{blue}{\left(-0.5 \cdot K\right)}}\right)}^{2}} \]
    5. Applied rewrites18.3%

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

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

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

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

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

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

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

        \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\color{blue}{\frac{\frac{1}{4} \cdot {U}^{2}}{{J}^{2}}} + 1} \]
      7. unpow2N/A

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

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

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

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

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

        \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{\frac{1}{4}}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
      13. lower-*.f649.8

        \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{0.25}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
    8. Applied rewrites9.8%

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

      \[\leadsto -1 \cdot \color{blue}{\left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
    10. Step-by-step derivation
      1. Applied rewrites29.9%

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

        \[\leadsto -1 \cdot \left(-U\right) \]
      3. Step-by-step derivation
        1. Applied rewrites29.1%

          \[\leadsto -1 \cdot \left(-U\right) \]
      4. Recombined 3 regimes into one program.
      5. Add Preprocessing

      Alternative 2: 84.6% accurate, 0.3× speedup?

      \[\begin{array}{l} U_m = \left|U\right| \\ J\_m = \left|J\right| \\ J\_s = \mathsf{copysign}\left(1, J\right) \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(-2 \cdot J\_m\right) \cdot t\_0\\ t_2 := t\_1 \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\_m\right) \cdot t\_0}\right)}^{2}}\\ J\_s \cdot \begin{array}{l} \mathbf{if}\;t\_2 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_2 \leq -1 \cdot 10^{+168}:\\ \;\;\;\;\left(\left(-2 \cdot J\_m\right) \cdot \cos \left(-0.5 \cdot K\right)\right) \cdot 1\\ \mathbf{elif}\;t\_2 \leq 4 \cdot 10^{+288}:\\ \;\;\;\;t\_1 \cdot \sqrt{\mathsf{fma}\left(\frac{0.25}{J\_m}, \frac{U\_m \cdot U\_m}{J\_m}, 1\right)}\\ \mathbf{else}:\\ \;\;\;\;-1 \cdot \left(-U\_m\right)\\ \end{array} \end{array} \end{array} \]
      U_m = (fabs.f64 U)
      J\_m = (fabs.f64 J)
      J\_s = (copysign.f64 #s(literal 1 binary64) J)
      (FPCore (J_s J_m K U_m)
       :precision binary64
       (let* ((t_0 (cos (/ K 2.0)))
              (t_1 (* (* -2.0 J_m) t_0))
              (t_2 (* t_1 (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J_m) t_0)) 2.0))))))
         (*
          J_s
          (if (<= t_2 (- INFINITY))
            (- U_m)
            (if (<= t_2 -1e+168)
              (* (* (* -2.0 J_m) (cos (* -0.5 K))) 1.0)
              (if (<= t_2 4e+288)
                (* t_1 (sqrt (fma (/ 0.25 J_m) (/ (* U_m U_m) J_m) 1.0)))
                (* -1.0 (- U_m))))))))
      U_m = fabs(U);
      J\_m = fabs(J);
      J\_s = copysign(1.0, J);
      double code(double J_s, double J_m, double K, double U_m) {
      	double t_0 = cos((K / 2.0));
      	double t_1 = (-2.0 * J_m) * t_0;
      	double t_2 = t_1 * sqrt((1.0 + pow((U_m / ((2.0 * J_m) * t_0)), 2.0)));
      	double tmp;
      	if (t_2 <= -((double) INFINITY)) {
      		tmp = -U_m;
      	} else if (t_2 <= -1e+168) {
      		tmp = ((-2.0 * J_m) * cos((-0.5 * K))) * 1.0;
      	} else if (t_2 <= 4e+288) {
      		tmp = t_1 * sqrt(fma((0.25 / J_m), ((U_m * U_m) / J_m), 1.0));
      	} else {
      		tmp = -1.0 * -U_m;
      	}
      	return J_s * tmp;
      }
      
      U_m = abs(U)
      J\_m = abs(J)
      J\_s = copysign(1.0, J)
      function code(J_s, J_m, K, U_m)
      	t_0 = cos(Float64(K / 2.0))
      	t_1 = Float64(Float64(-2.0 * J_m) * t_0)
      	t_2 = Float64(t_1 * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J_m) * t_0)) ^ 2.0))))
      	tmp = 0.0
      	if (t_2 <= Float64(-Inf))
      		tmp = Float64(-U_m);
      	elseif (t_2 <= -1e+168)
      		tmp = Float64(Float64(Float64(-2.0 * J_m) * cos(Float64(-0.5 * K))) * 1.0);
      	elseif (t_2 <= 4e+288)
      		tmp = Float64(t_1 * sqrt(fma(Float64(0.25 / J_m), Float64(Float64(U_m * U_m) / J_m), 1.0)));
      	else
      		tmp = Float64(-1.0 * Float64(-U_m));
      	end
      	return Float64(J_s * tmp)
      end
      
      U_m = N[Abs[U], $MachinePrecision]
      J\_m = N[Abs[J], $MachinePrecision]
      J\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[J]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
      code[J$95$s_, J$95$m_, 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$95$m), $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$95$m), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, N[(J$95$s * If[LessEqual[t$95$2, (-Infinity)], (-U$95$m), If[LessEqual[t$95$2, -1e+168], N[(N[(N[(-2.0 * J$95$m), $MachinePrecision] * N[Cos[N[(-0.5 * K), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * 1.0), $MachinePrecision], If[LessEqual[t$95$2, 4e+288], N[(t$95$1 * N[Sqrt[N[(N[(0.25 / J$95$m), $MachinePrecision] * N[(N[(U$95$m * U$95$m), $MachinePrecision] / J$95$m), $MachinePrecision] + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(-1.0 * (-U$95$m)), $MachinePrecision]]]]), $MachinePrecision]]]]
      
      \begin{array}{l}
      U_m = \left|U\right|
      \\
      J\_m = \left|J\right|
      \\
      J\_s = \mathsf{copysign}\left(1, J\right)
      
      \\
      \begin{array}{l}
      t_0 := \cos \left(\frac{K}{2}\right)\\
      t_1 := \left(-2 \cdot J\_m\right) \cdot t\_0\\
      t_2 := t\_1 \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\_m\right) \cdot t\_0}\right)}^{2}}\\
      J\_s \cdot \begin{array}{l}
      \mathbf{if}\;t\_2 \leq -\infty:\\
      \;\;\;\;-U\_m\\
      
      \mathbf{elif}\;t\_2 \leq -1 \cdot 10^{+168}:\\
      \;\;\;\;\left(\left(-2 \cdot J\_m\right) \cdot \cos \left(-0.5 \cdot K\right)\right) \cdot 1\\
      
      \mathbf{elif}\;t\_2 \leq 4 \cdot 10^{+288}:\\
      \;\;\;\;t\_1 \cdot \sqrt{\mathsf{fma}\left(\frac{0.25}{J\_m}, \frac{U\_m \cdot U\_m}{J\_m}, 1\right)}\\
      
      \mathbf{else}:\\
      \;\;\;\;-1 \cdot \left(-U\_m\right)\\
      
      
      \end{array}
      \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 4.7%

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

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

            \[\leadsto \color{blue}{\mathsf{neg}\left(U\right)} \]
          2. lower-neg.f6463.3

            \[\leadsto \color{blue}{-U} \]
        5. Applied rewrites63.3%

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

        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))))) < -9.9999999999999993e167

        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. Add Preprocessing
        3. Taylor expanded in J around inf

          \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \color{blue}{1} \]
        4. Step-by-step derivation
          1. Applied rewrites78.8%

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

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

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

              \[\leadsto \left(\left(-2 \cdot J\right) \cdot \color{blue}{\cos \left(\mathsf{neg}\left(\frac{1}{2} \cdot K\right)\right)}\right) \cdot 1 \]
            3. distribute-lft-neg-inN/A

              \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \color{blue}{\left(\left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot K\right)}\right) \cdot 1 \]
            4. metadata-evalN/A

              \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\color{blue}{\frac{-1}{2}} \cdot K\right)\right) \cdot 1 \]
            5. lower-*.f6478.8

              \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \color{blue}{\left(-0.5 \cdot K\right)}\right) \cdot 1 \]
          4. Applied rewrites78.8%

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

          if -9.9999999999999993e167 < (*.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))))) < 4e288

          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. Add Preprocessing
          3. Taylor expanded in K around 0

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

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

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

              \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{\color{blue}{\frac{\frac{1}{4} \cdot {U}^{2}}{{J}^{2}}} + 1} \]
            4. unpow2N/A

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

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

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

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

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

              \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{\mathsf{fma}\left(\frac{\frac{1}{4}}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
            10. lower-*.f6482.9

              \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{\mathsf{fma}\left(\frac{0.25}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
          5. Applied rewrites82.9%

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

          if 4e288 < (*.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 18.3%

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

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

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

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

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

              \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\color{blue}{\frac{-1}{2}} \cdot K\right)}\right)}^{2}} \]
            5. lower-*.f6418.3

              \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \color{blue}{\left(-0.5 \cdot K\right)}}\right)}^{2}} \]
          5. Applied rewrites18.3%

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

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

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

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

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

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

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

              \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\color{blue}{\frac{\frac{1}{4} \cdot {U}^{2}}{{J}^{2}}} + 1} \]
            7. unpow2N/A

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

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

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

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

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

              \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{\frac{1}{4}}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
            13. lower-*.f649.8

              \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{0.25}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
          8. Applied rewrites9.8%

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

            \[\leadsto -1 \cdot \color{blue}{\left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
          10. Step-by-step derivation
            1. Applied rewrites29.9%

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

              \[\leadsto -1 \cdot \left(-U\right) \]
            3. Step-by-step derivation
              1. Applied rewrites29.1%

                \[\leadsto -1 \cdot \left(-U\right) \]
            4. Recombined 4 regimes into one program.
            5. Add Preprocessing

            Alternative 3: 71.5% accurate, 0.3× speedup?

            \[\begin{array}{l} U_m = \left|U\right| \\ J\_m = \left|J\right| \\ J\_s = \mathsf{copysign}\left(1, J\right) \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(\left(-2 \cdot J\_m\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\_m\right) \cdot t\_0}\right)}^{2}}\\ J\_s \cdot \begin{array}{l} \mathbf{if}\;t\_1 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_1 \leq -1 \cdot 10^{+168}:\\ \;\;\;\;\left(-2 \cdot J\_m\right) \cdot 1\\ \mathbf{elif}\;t\_1 \leq -2 \cdot 10^{-254}:\\ \;\;\;\;\sqrt{\mathsf{fma}\left(\frac{0.25}{J\_m}, \frac{U\_m \cdot U\_m}{J\_m}, 1\right)} \cdot \left(-2 \cdot J\_m\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\frac{-2}{-U\_m} \cdot \left(J\_m \cdot \frac{J\_m}{U\_m}\right) - -1\right) \cdot U\_m\\ \end{array} \end{array} \end{array} \]
            U_m = (fabs.f64 U)
            J\_m = (fabs.f64 J)
            J\_s = (copysign.f64 #s(literal 1 binary64) J)
            (FPCore (J_s J_m K U_m)
             :precision binary64
             (let* ((t_0 (cos (/ K 2.0)))
                    (t_1
                     (*
                      (* (* -2.0 J_m) t_0)
                      (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J_m) t_0)) 2.0))))))
               (*
                J_s
                (if (<= t_1 (- INFINITY))
                  (- U_m)
                  (if (<= t_1 -1e+168)
                    (* (* -2.0 J_m) 1.0)
                    (if (<= t_1 -2e-254)
                      (* (sqrt (fma (/ 0.25 J_m) (/ (* U_m U_m) J_m) 1.0)) (* -2.0 J_m))
                      (* (- (* (/ -2.0 (- U_m)) (* J_m (/ J_m U_m))) -1.0) U_m)))))))
            U_m = fabs(U);
            J\_m = fabs(J);
            J\_s = copysign(1.0, J);
            double code(double J_s, double J_m, double K, double U_m) {
            	double t_0 = cos((K / 2.0));
            	double t_1 = ((-2.0 * J_m) * t_0) * sqrt((1.0 + pow((U_m / ((2.0 * J_m) * t_0)), 2.0)));
            	double tmp;
            	if (t_1 <= -((double) INFINITY)) {
            		tmp = -U_m;
            	} else if (t_1 <= -1e+168) {
            		tmp = (-2.0 * J_m) * 1.0;
            	} else if (t_1 <= -2e-254) {
            		tmp = sqrt(fma((0.25 / J_m), ((U_m * U_m) / J_m), 1.0)) * (-2.0 * J_m);
            	} else {
            		tmp = (((-2.0 / -U_m) * (J_m * (J_m / U_m))) - -1.0) * U_m;
            	}
            	return J_s * tmp;
            }
            
            U_m = abs(U)
            J\_m = abs(J)
            J\_s = copysign(1.0, J)
            function code(J_s, J_m, K, U_m)
            	t_0 = cos(Float64(K / 2.0))
            	t_1 = Float64(Float64(Float64(-2.0 * J_m) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J_m) * t_0)) ^ 2.0))))
            	tmp = 0.0
            	if (t_1 <= Float64(-Inf))
            		tmp = Float64(-U_m);
            	elseif (t_1 <= -1e+168)
            		tmp = Float64(Float64(-2.0 * J_m) * 1.0);
            	elseif (t_1 <= -2e-254)
            		tmp = Float64(sqrt(fma(Float64(0.25 / J_m), Float64(Float64(U_m * U_m) / J_m), 1.0)) * Float64(-2.0 * J_m));
            	else
            		tmp = Float64(Float64(Float64(Float64(-2.0 / Float64(-U_m)) * Float64(J_m * Float64(J_m / U_m))) - -1.0) * U_m);
            	end
            	return Float64(J_s * tmp)
            end
            
            U_m = N[Abs[U], $MachinePrecision]
            J\_m = N[Abs[J], $MachinePrecision]
            J\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[J]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
            code[J$95$s_, J$95$m_, 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$95$m), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(2.0 * J$95$m), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, N[(J$95$s * If[LessEqual[t$95$1, (-Infinity)], (-U$95$m), If[LessEqual[t$95$1, -1e+168], N[(N[(-2.0 * J$95$m), $MachinePrecision] * 1.0), $MachinePrecision], If[LessEqual[t$95$1, -2e-254], N[(N[Sqrt[N[(N[(0.25 / J$95$m), $MachinePrecision] * N[(N[(U$95$m * U$95$m), $MachinePrecision] / J$95$m), $MachinePrecision] + 1.0), $MachinePrecision]], $MachinePrecision] * N[(-2.0 * J$95$m), $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[(-2.0 / (-U$95$m)), $MachinePrecision] * N[(J$95$m * N[(J$95$m / U$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - -1.0), $MachinePrecision] * U$95$m), $MachinePrecision]]]]), $MachinePrecision]]]
            
            \begin{array}{l}
            U_m = \left|U\right|
            \\
            J\_m = \left|J\right|
            \\
            J\_s = \mathsf{copysign}\left(1, J\right)
            
            \\
            \begin{array}{l}
            t_0 := \cos \left(\frac{K}{2}\right)\\
            t_1 := \left(\left(-2 \cdot J\_m\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\_m\right) \cdot t\_0}\right)}^{2}}\\
            J\_s \cdot \begin{array}{l}
            \mathbf{if}\;t\_1 \leq -\infty:\\
            \;\;\;\;-U\_m\\
            
            \mathbf{elif}\;t\_1 \leq -1 \cdot 10^{+168}:\\
            \;\;\;\;\left(-2 \cdot J\_m\right) \cdot 1\\
            
            \mathbf{elif}\;t\_1 \leq -2 \cdot 10^{-254}:\\
            \;\;\;\;\sqrt{\mathsf{fma}\left(\frac{0.25}{J\_m}, \frac{U\_m \cdot U\_m}{J\_m}, 1\right)} \cdot \left(-2 \cdot J\_m\right)\\
            
            \mathbf{else}:\\
            \;\;\;\;\left(\frac{-2}{-U\_m} \cdot \left(J\_m \cdot \frac{J\_m}{U\_m}\right) - -1\right) \cdot U\_m\\
            
            
            \end{array}
            \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 4.7%

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

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

                  \[\leadsto \color{blue}{\mathsf{neg}\left(U\right)} \]
                2. lower-neg.f6463.3

                  \[\leadsto \color{blue}{-U} \]
              5. Applied rewrites63.3%

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

              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))))) < -9.9999999999999993e167

              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. Add Preprocessing
              3. Taylor expanded in K around inf

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

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

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

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

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

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

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

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

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

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

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

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

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

                  \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\color{blue}{\frac{\frac{1}{4} \cdot {U}^{2}}{{J}^{2}}} + 1} \]
                7. unpow2N/A

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

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

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

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

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

                  \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{\frac{1}{4}}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
                13. lower-*.f6427.2

                  \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{0.25}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
              8. Applied rewrites27.2%

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

                \[\leadsto \left(-2 \cdot J\right) \cdot 1 \]
              10. Step-by-step derivation
                1. Applied rewrites37.3%

                  \[\leadsto \left(-2 \cdot J\right) \cdot 1 \]

                if -9.9999999999999993e167 < (*.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))))) < -1.9999999999999998e-254

                1. Initial program 99.9%

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

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

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

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

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

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

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

                    \[\leadsto \sqrt{\color{blue}{\frac{\frac{1}{4} \cdot {U}^{2}}{{J}^{2}}} + 1} \cdot \left(-2 \cdot J\right) \]
                  7. unpow2N/A

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

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

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

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

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

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

                    \[\leadsto \sqrt{\mathsf{fma}\left(\frac{\frac{1}{4}}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \cdot \left(-2 \cdot J\right) \]
                  14. lower-*.f6457.9

                    \[\leadsto \sqrt{\mathsf{fma}\left(\frac{0.25}{J}, \frac{U \cdot U}{J}, 1\right)} \cdot \color{blue}{\left(-2 \cdot J\right)} \]
                5. Applied rewrites57.9%

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

                if -1.9999999999999998e-254 < (*.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 68.1%

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

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

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

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

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

                    \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\color{blue}{\frac{-1}{2}} \cdot K\right)}\right)}^{2}} \]
                  5. lower-*.f6468.1

                    \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \color{blue}{\left(-0.5 \cdot K\right)}}\right)}^{2}} \]
                5. Applied rewrites68.1%

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

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

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

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

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

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

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

                    \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\color{blue}{\frac{\frac{1}{4} \cdot {U}^{2}}{{J}^{2}}} + 1} \]
                  7. unpow2N/A

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

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

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

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

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

                    \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{\frac{1}{4}}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
                  13. lower-*.f6434.4

                    \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{0.25}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
                8. Applied rewrites34.4%

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

                  \[\leadsto -1 \cdot \color{blue}{\left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
                10. Step-by-step derivation
                  1. Applied rewrites19.0%

                    \[\leadsto \left(\frac{-2}{U} \cdot \frac{J \cdot J}{U} - 1\right) \cdot \color{blue}{\left(-U\right)} \]
                  2. Step-by-step derivation
                    1. Applied rewrites19.7%

                      \[\leadsto \left(\frac{-2}{U} \cdot \left(J \cdot \frac{J}{U}\right) - 1\right) \cdot \left(-U\right) \]
                  3. Recombined 4 regimes into one program.
                  4. Final simplification34.9%

                    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \leq -\infty:\\ \;\;\;\;-U\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \leq -1 \cdot 10^{+168}:\\ \;\;\;\;\left(-2 \cdot J\right) \cdot 1\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \leq -2 \cdot 10^{-254}:\\ \;\;\;\;\sqrt{\mathsf{fma}\left(\frac{0.25}{J}, \frac{U \cdot U}{J}, 1\right)} \cdot \left(-2 \cdot J\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\frac{-2}{-U} \cdot \left(J \cdot \frac{J}{U}\right) - -1\right) \cdot U\\ \end{array} \]
                  5. Add Preprocessing

                  Alternative 4: 78.2% accurate, 0.4× speedup?

                  \[\begin{array}{l} U_m = \left|U\right| \\ J\_m = \left|J\right| \\ J\_s = \mathsf{copysign}\left(1, J\right) \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(\left(-2 \cdot J\_m\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\_m\right) \cdot t\_0}\right)}^{2}}\\ J\_s \cdot \begin{array}{l} \mathbf{if}\;t\_1 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_1 \leq 4 \cdot 10^{+288}:\\ \;\;\;\;\left(\left(-2 \cdot J\_m\right) \cdot \cos \left(-0.5 \cdot K\right)\right) \cdot 1\\ \mathbf{else}:\\ \;\;\;\;-1 \cdot \left(-U\_m\right)\\ \end{array} \end{array} \end{array} \]
                  U_m = (fabs.f64 U)
                  J\_m = (fabs.f64 J)
                  J\_s = (copysign.f64 #s(literal 1 binary64) J)
                  (FPCore (J_s J_m K U_m)
                   :precision binary64
                   (let* ((t_0 (cos (/ K 2.0)))
                          (t_1
                           (*
                            (* (* -2.0 J_m) t_0)
                            (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J_m) t_0)) 2.0))))))
                     (*
                      J_s
                      (if (<= t_1 (- INFINITY))
                        (- U_m)
                        (if (<= t_1 4e+288)
                          (* (* (* -2.0 J_m) (cos (* -0.5 K))) 1.0)
                          (* -1.0 (- U_m)))))))
                  U_m = fabs(U);
                  J\_m = fabs(J);
                  J\_s = copysign(1.0, J);
                  double code(double J_s, double J_m, double K, double U_m) {
                  	double t_0 = cos((K / 2.0));
                  	double t_1 = ((-2.0 * J_m) * t_0) * sqrt((1.0 + pow((U_m / ((2.0 * J_m) * t_0)), 2.0)));
                  	double tmp;
                  	if (t_1 <= -((double) INFINITY)) {
                  		tmp = -U_m;
                  	} else if (t_1 <= 4e+288) {
                  		tmp = ((-2.0 * J_m) * cos((-0.5 * K))) * 1.0;
                  	} else {
                  		tmp = -1.0 * -U_m;
                  	}
                  	return J_s * tmp;
                  }
                  
                  U_m = Math.abs(U);
                  J\_m = Math.abs(J);
                  J\_s = Math.copySign(1.0, J);
                  public static double code(double J_s, double J_m, double K, double U_m) {
                  	double t_0 = Math.cos((K / 2.0));
                  	double t_1 = ((-2.0 * J_m) * t_0) * Math.sqrt((1.0 + Math.pow((U_m / ((2.0 * J_m) * t_0)), 2.0)));
                  	double tmp;
                  	if (t_1 <= -Double.POSITIVE_INFINITY) {
                  		tmp = -U_m;
                  	} else if (t_1 <= 4e+288) {
                  		tmp = ((-2.0 * J_m) * Math.cos((-0.5 * K))) * 1.0;
                  	} else {
                  		tmp = -1.0 * -U_m;
                  	}
                  	return J_s * tmp;
                  }
                  
                  U_m = math.fabs(U)
                  J\_m = math.fabs(J)
                  J\_s = math.copysign(1.0, J)
                  def code(J_s, J_m, K, U_m):
                  	t_0 = math.cos((K / 2.0))
                  	t_1 = ((-2.0 * J_m) * t_0) * math.sqrt((1.0 + math.pow((U_m / ((2.0 * J_m) * t_0)), 2.0)))
                  	tmp = 0
                  	if t_1 <= -math.inf:
                  		tmp = -U_m
                  	elif t_1 <= 4e+288:
                  		tmp = ((-2.0 * J_m) * math.cos((-0.5 * K))) * 1.0
                  	else:
                  		tmp = -1.0 * -U_m
                  	return J_s * tmp
                  
                  U_m = abs(U)
                  J\_m = abs(J)
                  J\_s = copysign(1.0, J)
                  function code(J_s, J_m, K, U_m)
                  	t_0 = cos(Float64(K / 2.0))
                  	t_1 = Float64(Float64(Float64(-2.0 * J_m) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J_m) * t_0)) ^ 2.0))))
                  	tmp = 0.0
                  	if (t_1 <= Float64(-Inf))
                  		tmp = Float64(-U_m);
                  	elseif (t_1 <= 4e+288)
                  		tmp = Float64(Float64(Float64(-2.0 * J_m) * cos(Float64(-0.5 * K))) * 1.0);
                  	else
                  		tmp = Float64(-1.0 * Float64(-U_m));
                  	end
                  	return Float64(J_s * tmp)
                  end
                  
                  U_m = abs(U);
                  J\_m = abs(J);
                  J\_s = sign(J) * abs(1.0);
                  function tmp_2 = code(J_s, J_m, K, U_m)
                  	t_0 = cos((K / 2.0));
                  	t_1 = ((-2.0 * J_m) * t_0) * sqrt((1.0 + ((U_m / ((2.0 * J_m) * t_0)) ^ 2.0)));
                  	tmp = 0.0;
                  	if (t_1 <= -Inf)
                  		tmp = -U_m;
                  	elseif (t_1 <= 4e+288)
                  		tmp = ((-2.0 * J_m) * cos((-0.5 * K))) * 1.0;
                  	else
                  		tmp = -1.0 * -U_m;
                  	end
                  	tmp_2 = J_s * tmp;
                  end
                  
                  U_m = N[Abs[U], $MachinePrecision]
                  J\_m = N[Abs[J], $MachinePrecision]
                  J\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[J]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
                  code[J$95$s_, J$95$m_, 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$95$m), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(2.0 * J$95$m), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, N[(J$95$s * If[LessEqual[t$95$1, (-Infinity)], (-U$95$m), If[LessEqual[t$95$1, 4e+288], N[(N[(N[(-2.0 * J$95$m), $MachinePrecision] * N[Cos[N[(-0.5 * K), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * 1.0), $MachinePrecision], N[(-1.0 * (-U$95$m)), $MachinePrecision]]]), $MachinePrecision]]]
                  
                  \begin{array}{l}
                  U_m = \left|U\right|
                  \\
                  J\_m = \left|J\right|
                  \\
                  J\_s = \mathsf{copysign}\left(1, J\right)
                  
                  \\
                  \begin{array}{l}
                  t_0 := \cos \left(\frac{K}{2}\right)\\
                  t_1 := \left(\left(-2 \cdot J\_m\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\_m\right) \cdot t\_0}\right)}^{2}}\\
                  J\_s \cdot \begin{array}{l}
                  \mathbf{if}\;t\_1 \leq -\infty:\\
                  \;\;\;\;-U\_m\\
                  
                  \mathbf{elif}\;t\_1 \leq 4 \cdot 10^{+288}:\\
                  \;\;\;\;\left(\left(-2 \cdot J\_m\right) \cdot \cos \left(-0.5 \cdot K\right)\right) \cdot 1\\
                  
                  \mathbf{else}:\\
                  \;\;\;\;-1 \cdot \left(-U\_m\right)\\
                  
                  
                  \end{array}
                  \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 4.7%

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

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

                        \[\leadsto \color{blue}{\mathsf{neg}\left(U\right)} \]
                      2. lower-neg.f6463.3

                        \[\leadsto \color{blue}{-U} \]
                    5. Applied rewrites63.3%

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

                    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))))) < 4e288

                    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. Add Preprocessing
                    3. Taylor expanded in J around inf

                      \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \color{blue}{1} \]
                    4. Step-by-step derivation
                      1. Applied rewrites76.6%

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

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

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

                          \[\leadsto \left(\left(-2 \cdot J\right) \cdot \color{blue}{\cos \left(\mathsf{neg}\left(\frac{1}{2} \cdot K\right)\right)}\right) \cdot 1 \]
                        3. distribute-lft-neg-inN/A

                          \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \color{blue}{\left(\left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot K\right)}\right) \cdot 1 \]
                        4. metadata-evalN/A

                          \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\color{blue}{\frac{-1}{2}} \cdot K\right)\right) \cdot 1 \]
                        5. lower-*.f6476.6

                          \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \color{blue}{\left(-0.5 \cdot K\right)}\right) \cdot 1 \]
                      4. Applied rewrites76.6%

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

                      if 4e288 < (*.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 18.3%

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

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

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

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

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

                          \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\color{blue}{\frac{-1}{2}} \cdot K\right)}\right)}^{2}} \]
                        5. lower-*.f6418.3

                          \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \color{blue}{\left(-0.5 \cdot K\right)}}\right)}^{2}} \]
                      5. Applied rewrites18.3%

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

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

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

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

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

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

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

                          \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\color{blue}{\frac{\frac{1}{4} \cdot {U}^{2}}{{J}^{2}}} + 1} \]
                        7. unpow2N/A

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

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

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

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

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

                          \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{\frac{1}{4}}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
                        13. lower-*.f649.8

                          \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{0.25}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
                      8. Applied rewrites9.8%

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

                        \[\leadsto -1 \cdot \color{blue}{\left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
                      10. Step-by-step derivation
                        1. Applied rewrites29.9%

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

                          \[\leadsto -1 \cdot \left(-U\right) \]
                        3. Step-by-step derivation
                          1. Applied rewrites29.1%

                            \[\leadsto -1 \cdot \left(-U\right) \]
                        4. Recombined 3 regimes into one program.
                        5. Add Preprocessing

                        Alternative 5: 62.7% accurate, 0.5× speedup?

                        \[\begin{array}{l} U_m = \left|U\right| \\ J\_m = \left|J\right| \\ J\_s = \mathsf{copysign}\left(1, J\right) \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(\left(-2 \cdot J\_m\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\_m\right) \cdot t\_0}\right)}^{2}}\\ J\_s \cdot \begin{array}{l} \mathbf{if}\;t\_1 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_1 \leq -2 \cdot 10^{-254}:\\ \;\;\;\;\left(-2 \cdot J\_m\right) \cdot 1\\ \mathbf{else}:\\ \;\;\;\;\left(\frac{-2}{-U\_m} \cdot \left(J\_m \cdot \frac{J\_m}{U\_m}\right) - -1\right) \cdot U\_m\\ \end{array} \end{array} \end{array} \]
                        U_m = (fabs.f64 U)
                        J\_m = (fabs.f64 J)
                        J\_s = (copysign.f64 #s(literal 1 binary64) J)
                        (FPCore (J_s J_m K U_m)
                         :precision binary64
                         (let* ((t_0 (cos (/ K 2.0)))
                                (t_1
                                 (*
                                  (* (* -2.0 J_m) t_0)
                                  (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J_m) t_0)) 2.0))))))
                           (*
                            J_s
                            (if (<= t_1 (- INFINITY))
                              (- U_m)
                              (if (<= t_1 -2e-254)
                                (* (* -2.0 J_m) 1.0)
                                (* (- (* (/ -2.0 (- U_m)) (* J_m (/ J_m U_m))) -1.0) U_m))))))
                        U_m = fabs(U);
                        J\_m = fabs(J);
                        J\_s = copysign(1.0, J);
                        double code(double J_s, double J_m, double K, double U_m) {
                        	double t_0 = cos((K / 2.0));
                        	double t_1 = ((-2.0 * J_m) * t_0) * sqrt((1.0 + pow((U_m / ((2.0 * J_m) * t_0)), 2.0)));
                        	double tmp;
                        	if (t_1 <= -((double) INFINITY)) {
                        		tmp = -U_m;
                        	} else if (t_1 <= -2e-254) {
                        		tmp = (-2.0 * J_m) * 1.0;
                        	} else {
                        		tmp = (((-2.0 / -U_m) * (J_m * (J_m / U_m))) - -1.0) * U_m;
                        	}
                        	return J_s * tmp;
                        }
                        
                        U_m = Math.abs(U);
                        J\_m = Math.abs(J);
                        J\_s = Math.copySign(1.0, J);
                        public static double code(double J_s, double J_m, double K, double U_m) {
                        	double t_0 = Math.cos((K / 2.0));
                        	double t_1 = ((-2.0 * J_m) * t_0) * Math.sqrt((1.0 + Math.pow((U_m / ((2.0 * J_m) * t_0)), 2.0)));
                        	double tmp;
                        	if (t_1 <= -Double.POSITIVE_INFINITY) {
                        		tmp = -U_m;
                        	} else if (t_1 <= -2e-254) {
                        		tmp = (-2.0 * J_m) * 1.0;
                        	} else {
                        		tmp = (((-2.0 / -U_m) * (J_m * (J_m / U_m))) - -1.0) * U_m;
                        	}
                        	return J_s * tmp;
                        }
                        
                        U_m = math.fabs(U)
                        J\_m = math.fabs(J)
                        J\_s = math.copysign(1.0, J)
                        def code(J_s, J_m, K, U_m):
                        	t_0 = math.cos((K / 2.0))
                        	t_1 = ((-2.0 * J_m) * t_0) * math.sqrt((1.0 + math.pow((U_m / ((2.0 * J_m) * t_0)), 2.0)))
                        	tmp = 0
                        	if t_1 <= -math.inf:
                        		tmp = -U_m
                        	elif t_1 <= -2e-254:
                        		tmp = (-2.0 * J_m) * 1.0
                        	else:
                        		tmp = (((-2.0 / -U_m) * (J_m * (J_m / U_m))) - -1.0) * U_m
                        	return J_s * tmp
                        
                        U_m = abs(U)
                        J\_m = abs(J)
                        J\_s = copysign(1.0, J)
                        function code(J_s, J_m, K, U_m)
                        	t_0 = cos(Float64(K / 2.0))
                        	t_1 = Float64(Float64(Float64(-2.0 * J_m) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J_m) * t_0)) ^ 2.0))))
                        	tmp = 0.0
                        	if (t_1 <= Float64(-Inf))
                        		tmp = Float64(-U_m);
                        	elseif (t_1 <= -2e-254)
                        		tmp = Float64(Float64(-2.0 * J_m) * 1.0);
                        	else
                        		tmp = Float64(Float64(Float64(Float64(-2.0 / Float64(-U_m)) * Float64(J_m * Float64(J_m / U_m))) - -1.0) * U_m);
                        	end
                        	return Float64(J_s * tmp)
                        end
                        
                        U_m = abs(U);
                        J\_m = abs(J);
                        J\_s = sign(J) * abs(1.0);
                        function tmp_2 = code(J_s, J_m, K, U_m)
                        	t_0 = cos((K / 2.0));
                        	t_1 = ((-2.0 * J_m) * t_0) * sqrt((1.0 + ((U_m / ((2.0 * J_m) * t_0)) ^ 2.0)));
                        	tmp = 0.0;
                        	if (t_1 <= -Inf)
                        		tmp = -U_m;
                        	elseif (t_1 <= -2e-254)
                        		tmp = (-2.0 * J_m) * 1.0;
                        	else
                        		tmp = (((-2.0 / -U_m) * (J_m * (J_m / U_m))) - -1.0) * U_m;
                        	end
                        	tmp_2 = J_s * tmp;
                        end
                        
                        U_m = N[Abs[U], $MachinePrecision]
                        J\_m = N[Abs[J], $MachinePrecision]
                        J\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[J]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
                        code[J$95$s_, J$95$m_, 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$95$m), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(2.0 * J$95$m), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, N[(J$95$s * If[LessEqual[t$95$1, (-Infinity)], (-U$95$m), If[LessEqual[t$95$1, -2e-254], N[(N[(-2.0 * J$95$m), $MachinePrecision] * 1.0), $MachinePrecision], N[(N[(N[(N[(-2.0 / (-U$95$m)), $MachinePrecision] * N[(J$95$m * N[(J$95$m / U$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - -1.0), $MachinePrecision] * U$95$m), $MachinePrecision]]]), $MachinePrecision]]]
                        
                        \begin{array}{l}
                        U_m = \left|U\right|
                        \\
                        J\_m = \left|J\right|
                        \\
                        J\_s = \mathsf{copysign}\left(1, J\right)
                        
                        \\
                        \begin{array}{l}
                        t_0 := \cos \left(\frac{K}{2}\right)\\
                        t_1 := \left(\left(-2 \cdot J\_m\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\_m\right) \cdot t\_0}\right)}^{2}}\\
                        J\_s \cdot \begin{array}{l}
                        \mathbf{if}\;t\_1 \leq -\infty:\\
                        \;\;\;\;-U\_m\\
                        
                        \mathbf{elif}\;t\_1 \leq -2 \cdot 10^{-254}:\\
                        \;\;\;\;\left(-2 \cdot J\_m\right) \cdot 1\\
                        
                        \mathbf{else}:\\
                        \;\;\;\;\left(\frac{-2}{-U\_m} \cdot \left(J\_m \cdot \frac{J\_m}{U\_m}\right) - -1\right) \cdot U\_m\\
                        
                        
                        \end{array}
                        \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 4.7%

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

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

                              \[\leadsto \color{blue}{\mathsf{neg}\left(U\right)} \]
                            2. lower-neg.f6463.3

                              \[\leadsto \color{blue}{-U} \]
                          5. Applied rewrites63.3%

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

                          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))))) < -1.9999999999999998e-254

                          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. Add Preprocessing
                          3. Taylor expanded in K around inf

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

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

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

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

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

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

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

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

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

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

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

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

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

                              \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\color{blue}{\frac{\frac{1}{4} \cdot {U}^{2}}{{J}^{2}}} + 1} \]
                            7. unpow2N/A

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

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

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

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

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

                              \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{\frac{1}{4}}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
                            13. lower-*.f6444.7

                              \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{0.25}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
                          8. Applied rewrites44.7%

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

                            \[\leadsto \left(-2 \cdot J\right) \cdot 1 \]
                          10. Step-by-step derivation
                            1. Applied rewrites39.0%

                              \[\leadsto \left(-2 \cdot J\right) \cdot 1 \]

                            if -1.9999999999999998e-254 < (*.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 68.1%

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

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

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

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

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

                                \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\color{blue}{\frac{-1}{2}} \cdot K\right)}\right)}^{2}} \]
                              5. lower-*.f6468.1

                                \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \color{blue}{\left(-0.5 \cdot K\right)}}\right)}^{2}} \]
                            5. Applied rewrites68.1%

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

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

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

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

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

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

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

                                \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\color{blue}{\frac{\frac{1}{4} \cdot {U}^{2}}{{J}^{2}}} + 1} \]
                              7. unpow2N/A

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

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

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

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

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

                                \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{\frac{1}{4}}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
                              13. lower-*.f6434.4

                                \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{0.25}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
                            8. Applied rewrites34.4%

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

                              \[\leadsto -1 \cdot \color{blue}{\left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
                            10. Step-by-step derivation
                              1. Applied rewrites19.0%

                                \[\leadsto \left(\frac{-2}{U} \cdot \frac{J \cdot J}{U} - 1\right) \cdot \color{blue}{\left(-U\right)} \]
                              2. Step-by-step derivation
                                1. Applied rewrites19.7%

                                  \[\leadsto \left(\frac{-2}{U} \cdot \left(J \cdot \frac{J}{U}\right) - 1\right) \cdot \left(-U\right) \]
                              3. Recombined 3 regimes into one program.
                              4. Final simplification31.3%

                                \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \leq -\infty:\\ \;\;\;\;-U\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \leq -2 \cdot 10^{-254}:\\ \;\;\;\;\left(-2 \cdot J\right) \cdot 1\\ \mathbf{else}:\\ \;\;\;\;\left(\frac{-2}{-U} \cdot \left(J \cdot \frac{J}{U}\right) - -1\right) \cdot U\\ \end{array} \]
                              5. Add Preprocessing

                              Alternative 6: 62.6% accurate, 0.5× speedup?

                              \[\begin{array}{l} U_m = \left|U\right| \\ J\_m = \left|J\right| \\ J\_s = \mathsf{copysign}\left(1, J\right) \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(\left(-2 \cdot J\_m\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\_m\right) \cdot t\_0}\right)}^{2}}\\ J\_s \cdot \begin{array}{l} \mathbf{if}\;t\_1 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_1 \leq -2 \cdot 10^{-254}:\\ \;\;\;\;\left(-2 \cdot J\_m\right) \cdot 1\\ \mathbf{else}:\\ \;\;\;\;-1 \cdot \left(-U\_m\right)\\ \end{array} \end{array} \end{array} \]
                              U_m = (fabs.f64 U)
                              J\_m = (fabs.f64 J)
                              J\_s = (copysign.f64 #s(literal 1 binary64) J)
                              (FPCore (J_s J_m K U_m)
                               :precision binary64
                               (let* ((t_0 (cos (/ K 2.0)))
                                      (t_1
                                       (*
                                        (* (* -2.0 J_m) t_0)
                                        (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J_m) t_0)) 2.0))))))
                                 (*
                                  J_s
                                  (if (<= t_1 (- INFINITY))
                                    (- U_m)
                                    (if (<= t_1 -2e-254) (* (* -2.0 J_m) 1.0) (* -1.0 (- U_m)))))))
                              U_m = fabs(U);
                              J\_m = fabs(J);
                              J\_s = copysign(1.0, J);
                              double code(double J_s, double J_m, double K, double U_m) {
                              	double t_0 = cos((K / 2.0));
                              	double t_1 = ((-2.0 * J_m) * t_0) * sqrt((1.0 + pow((U_m / ((2.0 * J_m) * t_0)), 2.0)));
                              	double tmp;
                              	if (t_1 <= -((double) INFINITY)) {
                              		tmp = -U_m;
                              	} else if (t_1 <= -2e-254) {
                              		tmp = (-2.0 * J_m) * 1.0;
                              	} else {
                              		tmp = -1.0 * -U_m;
                              	}
                              	return J_s * tmp;
                              }
                              
                              U_m = Math.abs(U);
                              J\_m = Math.abs(J);
                              J\_s = Math.copySign(1.0, J);
                              public static double code(double J_s, double J_m, double K, double U_m) {
                              	double t_0 = Math.cos((K / 2.0));
                              	double t_1 = ((-2.0 * J_m) * t_0) * Math.sqrt((1.0 + Math.pow((U_m / ((2.0 * J_m) * t_0)), 2.0)));
                              	double tmp;
                              	if (t_1 <= -Double.POSITIVE_INFINITY) {
                              		tmp = -U_m;
                              	} else if (t_1 <= -2e-254) {
                              		tmp = (-2.0 * J_m) * 1.0;
                              	} else {
                              		tmp = -1.0 * -U_m;
                              	}
                              	return J_s * tmp;
                              }
                              
                              U_m = math.fabs(U)
                              J\_m = math.fabs(J)
                              J\_s = math.copysign(1.0, J)
                              def code(J_s, J_m, K, U_m):
                              	t_0 = math.cos((K / 2.0))
                              	t_1 = ((-2.0 * J_m) * t_0) * math.sqrt((1.0 + math.pow((U_m / ((2.0 * J_m) * t_0)), 2.0)))
                              	tmp = 0
                              	if t_1 <= -math.inf:
                              		tmp = -U_m
                              	elif t_1 <= -2e-254:
                              		tmp = (-2.0 * J_m) * 1.0
                              	else:
                              		tmp = -1.0 * -U_m
                              	return J_s * tmp
                              
                              U_m = abs(U)
                              J\_m = abs(J)
                              J\_s = copysign(1.0, J)
                              function code(J_s, J_m, K, U_m)
                              	t_0 = cos(Float64(K / 2.0))
                              	t_1 = Float64(Float64(Float64(-2.0 * J_m) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J_m) * t_0)) ^ 2.0))))
                              	tmp = 0.0
                              	if (t_1 <= Float64(-Inf))
                              		tmp = Float64(-U_m);
                              	elseif (t_1 <= -2e-254)
                              		tmp = Float64(Float64(-2.0 * J_m) * 1.0);
                              	else
                              		tmp = Float64(-1.0 * Float64(-U_m));
                              	end
                              	return Float64(J_s * tmp)
                              end
                              
                              U_m = abs(U);
                              J\_m = abs(J);
                              J\_s = sign(J) * abs(1.0);
                              function tmp_2 = code(J_s, J_m, K, U_m)
                              	t_0 = cos((K / 2.0));
                              	t_1 = ((-2.0 * J_m) * t_0) * sqrt((1.0 + ((U_m / ((2.0 * J_m) * t_0)) ^ 2.0)));
                              	tmp = 0.0;
                              	if (t_1 <= -Inf)
                              		tmp = -U_m;
                              	elseif (t_1 <= -2e-254)
                              		tmp = (-2.0 * J_m) * 1.0;
                              	else
                              		tmp = -1.0 * -U_m;
                              	end
                              	tmp_2 = J_s * tmp;
                              end
                              
                              U_m = N[Abs[U], $MachinePrecision]
                              J\_m = N[Abs[J], $MachinePrecision]
                              J\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[J]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
                              code[J$95$s_, J$95$m_, 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$95$m), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(2.0 * J$95$m), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, N[(J$95$s * If[LessEqual[t$95$1, (-Infinity)], (-U$95$m), If[LessEqual[t$95$1, -2e-254], N[(N[(-2.0 * J$95$m), $MachinePrecision] * 1.0), $MachinePrecision], N[(-1.0 * (-U$95$m)), $MachinePrecision]]]), $MachinePrecision]]]
                              
                              \begin{array}{l}
                              U_m = \left|U\right|
                              \\
                              J\_m = \left|J\right|
                              \\
                              J\_s = \mathsf{copysign}\left(1, J\right)
                              
                              \\
                              \begin{array}{l}
                              t_0 := \cos \left(\frac{K}{2}\right)\\
                              t_1 := \left(\left(-2 \cdot J\_m\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\_m\right) \cdot t\_0}\right)}^{2}}\\
                              J\_s \cdot \begin{array}{l}
                              \mathbf{if}\;t\_1 \leq -\infty:\\
                              \;\;\;\;-U\_m\\
                              
                              \mathbf{elif}\;t\_1 \leq -2 \cdot 10^{-254}:\\
                              \;\;\;\;\left(-2 \cdot J\_m\right) \cdot 1\\
                              
                              \mathbf{else}:\\
                              \;\;\;\;-1 \cdot \left(-U\_m\right)\\
                              
                              
                              \end{array}
                              \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 4.7%

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

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

                                    \[\leadsto \color{blue}{\mathsf{neg}\left(U\right)} \]
                                  2. lower-neg.f6463.3

                                    \[\leadsto \color{blue}{-U} \]
                                5. Applied rewrites63.3%

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

                                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))))) < -1.9999999999999998e-254

                                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. Add Preprocessing
                                3. Taylor expanded in K around inf

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

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

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

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

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

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

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

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

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

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

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

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

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

                                    \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\color{blue}{\frac{\frac{1}{4} \cdot {U}^{2}}{{J}^{2}}} + 1} \]
                                  7. unpow2N/A

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

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

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

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

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

                                    \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{\frac{1}{4}}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
                                  13. lower-*.f6444.7

                                    \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{0.25}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
                                8. Applied rewrites44.7%

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

                                  \[\leadsto \left(-2 \cdot J\right) \cdot 1 \]
                                10. Step-by-step derivation
                                  1. Applied rewrites39.0%

                                    \[\leadsto \left(-2 \cdot J\right) \cdot 1 \]

                                  if -1.9999999999999998e-254 < (*.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 68.1%

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

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

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

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

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

                                      \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\color{blue}{\frac{-1}{2}} \cdot K\right)}\right)}^{2}} \]
                                    5. lower-*.f6468.1

                                      \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \color{blue}{\left(-0.5 \cdot K\right)}}\right)}^{2}} \]
                                  5. Applied rewrites68.1%

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

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

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

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

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

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

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

                                      \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\color{blue}{\frac{\frac{1}{4} \cdot {U}^{2}}{{J}^{2}}} + 1} \]
                                    7. unpow2N/A

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

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

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

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

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

                                      \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{\frac{1}{4}}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
                                    13. lower-*.f6434.4

                                      \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{0.25}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
                                  8. Applied rewrites34.4%

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

                                    \[\leadsto -1 \cdot \color{blue}{\left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
                                  10. Step-by-step derivation
                                    1. Applied rewrites19.0%

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

                                      \[\leadsto -1 \cdot \left(-U\right) \]
                                    3. Step-by-step derivation
                                      1. Applied rewrites19.5%

                                        \[\leadsto -1 \cdot \left(-U\right) \]
                                    4. Recombined 3 regimes into one program.
                                    5. Add Preprocessing

                                    Alternative 7: 53.1% accurate, 1.0× speedup?

                                    \[\begin{array}{l} U_m = \left|U\right| \\ J\_m = \left|J\right| \\ J\_s = \mathsf{copysign}\left(1, J\right) \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ J\_s \cdot \begin{array}{l} \mathbf{if}\;\left(\left(-2 \cdot J\_m\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\_m\right) \cdot t\_0}\right)}^{2}} \leq -2 \cdot 10^{-254}:\\ \;\;\;\;-U\_m\\ \mathbf{else}:\\ \;\;\;\;-1 \cdot \left(-U\_m\right)\\ \end{array} \end{array} \end{array} \]
                                    U_m = (fabs.f64 U)
                                    J\_m = (fabs.f64 J)
                                    J\_s = (copysign.f64 #s(literal 1 binary64) J)
                                    (FPCore (J_s J_m K U_m)
                                     :precision binary64
                                     (let* ((t_0 (cos (/ K 2.0))))
                                       (*
                                        J_s
                                        (if (<=
                                             (*
                                              (* (* -2.0 J_m) t_0)
                                              (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J_m) t_0)) 2.0))))
                                             -2e-254)
                                          (- U_m)
                                          (* -1.0 (- U_m))))))
                                    U_m = fabs(U);
                                    J\_m = fabs(J);
                                    J\_s = copysign(1.0, J);
                                    double code(double J_s, double J_m, double K, double U_m) {
                                    	double t_0 = cos((K / 2.0));
                                    	double tmp;
                                    	if ((((-2.0 * J_m) * t_0) * sqrt((1.0 + pow((U_m / ((2.0 * J_m) * t_0)), 2.0)))) <= -2e-254) {
                                    		tmp = -U_m;
                                    	} else {
                                    		tmp = -1.0 * -U_m;
                                    	}
                                    	return J_s * tmp;
                                    }
                                    
                                    U_m =     private
                                    J\_m =     private
                                    J\_s =     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_s, j_m, k, u_m)
                                    use fmin_fmax_functions
                                        real(8), intent (in) :: j_s
                                        real(8), intent (in) :: j_m
                                        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_m) * t_0) * sqrt((1.0d0 + ((u_m / ((2.0d0 * j_m) * t_0)) ** 2.0d0)))) <= (-2d-254)) then
                                            tmp = -u_m
                                        else
                                            tmp = (-1.0d0) * -u_m
                                        end if
                                        code = j_s * tmp
                                    end function
                                    
                                    U_m = Math.abs(U);
                                    J\_m = Math.abs(J);
                                    J\_s = Math.copySign(1.0, J);
                                    public static double code(double J_s, double J_m, double K, double U_m) {
                                    	double t_0 = Math.cos((K / 2.0));
                                    	double tmp;
                                    	if ((((-2.0 * J_m) * t_0) * Math.sqrt((1.0 + Math.pow((U_m / ((2.0 * J_m) * t_0)), 2.0)))) <= -2e-254) {
                                    		tmp = -U_m;
                                    	} else {
                                    		tmp = -1.0 * -U_m;
                                    	}
                                    	return J_s * tmp;
                                    }
                                    
                                    U_m = math.fabs(U)
                                    J\_m = math.fabs(J)
                                    J\_s = math.copysign(1.0, J)
                                    def code(J_s, J_m, K, U_m):
                                    	t_0 = math.cos((K / 2.0))
                                    	tmp = 0
                                    	if (((-2.0 * J_m) * t_0) * math.sqrt((1.0 + math.pow((U_m / ((2.0 * J_m) * t_0)), 2.0)))) <= -2e-254:
                                    		tmp = -U_m
                                    	else:
                                    		tmp = -1.0 * -U_m
                                    	return J_s * tmp
                                    
                                    U_m = abs(U)
                                    J\_m = abs(J)
                                    J\_s = copysign(1.0, J)
                                    function code(J_s, J_m, K, U_m)
                                    	t_0 = cos(Float64(K / 2.0))
                                    	tmp = 0.0
                                    	if (Float64(Float64(Float64(-2.0 * J_m) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J_m) * t_0)) ^ 2.0)))) <= -2e-254)
                                    		tmp = Float64(-U_m);
                                    	else
                                    		tmp = Float64(-1.0 * Float64(-U_m));
                                    	end
                                    	return Float64(J_s * tmp)
                                    end
                                    
                                    U_m = abs(U);
                                    J\_m = abs(J);
                                    J\_s = sign(J) * abs(1.0);
                                    function tmp_2 = code(J_s, J_m, K, U_m)
                                    	t_0 = cos((K / 2.0));
                                    	tmp = 0.0;
                                    	if ((((-2.0 * J_m) * t_0) * sqrt((1.0 + ((U_m / ((2.0 * J_m) * t_0)) ^ 2.0)))) <= -2e-254)
                                    		tmp = -U_m;
                                    	else
                                    		tmp = -1.0 * -U_m;
                                    	end
                                    	tmp_2 = J_s * tmp;
                                    end
                                    
                                    U_m = N[Abs[U], $MachinePrecision]
                                    J\_m = N[Abs[J], $MachinePrecision]
                                    J\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[J]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
                                    code[J$95$s_, J$95$m_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, N[(J$95$s * If[LessEqual[N[(N[(N[(-2.0 * J$95$m), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(2.0 * J$95$m), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], -2e-254], (-U$95$m), N[(-1.0 * (-U$95$m)), $MachinePrecision]]), $MachinePrecision]]
                                    
                                    \begin{array}{l}
                                    U_m = \left|U\right|
                                    \\
                                    J\_m = \left|J\right|
                                    \\
                                    J\_s = \mathsf{copysign}\left(1, J\right)
                                    
                                    \\
                                    \begin{array}{l}
                                    t_0 := \cos \left(\frac{K}{2}\right)\\
                                    J\_s \cdot \begin{array}{l}
                                    \mathbf{if}\;\left(\left(-2 \cdot J\_m\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\_m\right) \cdot t\_0}\right)}^{2}} \leq -2 \cdot 10^{-254}:\\
                                    \;\;\;\;-U\_m\\
                                    
                                    \mathbf{else}:\\
                                    \;\;\;\;-1 \cdot \left(-U\_m\right)\\
                                    
                                    
                                    \end{array}
                                    \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))))) < -1.9999999999999998e-254

                                      1. Initial program 78.4%

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

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

                                          \[\leadsto \color{blue}{\mathsf{neg}\left(U\right)} \]
                                        2. lower-neg.f6427.8

                                          \[\leadsto \color{blue}{-U} \]
                                      5. Applied rewrites27.8%

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

                                      if -1.9999999999999998e-254 < (*.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 68.1%

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

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

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

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

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

                                          \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\color{blue}{\frac{-1}{2}} \cdot K\right)}\right)}^{2}} \]
                                        5. lower-*.f6468.1

                                          \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \color{blue}{\left(-0.5 \cdot K\right)}}\right)}^{2}} \]
                                      5. Applied rewrites68.1%

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

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

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

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

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

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

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

                                          \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\color{blue}{\frac{\frac{1}{4} \cdot {U}^{2}}{{J}^{2}}} + 1} \]
                                        7. unpow2N/A

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

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

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

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

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

                                          \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{\frac{1}{4}}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
                                        13. lower-*.f6434.4

                                          \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(\frac{0.25}{J}, \frac{\color{blue}{U \cdot U}}{J}, 1\right)} \]
                                      8. Applied rewrites34.4%

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

                                        \[\leadsto -1 \cdot \color{blue}{\left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
                                      10. Step-by-step derivation
                                        1. Applied rewrites19.0%

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

                                          \[\leadsto -1 \cdot \left(-U\right) \]
                                        3. Step-by-step derivation
                                          1. Applied rewrites19.5%

                                            \[\leadsto -1 \cdot \left(-U\right) \]
                                        4. Recombined 2 regimes into one program.
                                        5. Add Preprocessing

                                        Alternative 8: 40.2% accurate, 124.3× speedup?

                                        \[\begin{array}{l} U_m = \left|U\right| \\ J\_m = \left|J\right| \\ J\_s = \mathsf{copysign}\left(1, J\right) \\ J\_s \cdot \left(-U\_m\right) \end{array} \]
                                        U_m = (fabs.f64 U)
                                        J\_m = (fabs.f64 J)
                                        J\_s = (copysign.f64 #s(literal 1 binary64) J)
                                        (FPCore (J_s J_m K U_m) :precision binary64 (* J_s (- U_m)))
                                        U_m = fabs(U);
                                        J\_m = fabs(J);
                                        J\_s = copysign(1.0, J);
                                        double code(double J_s, double J_m, double K, double U_m) {
                                        	return J_s * -U_m;
                                        }
                                        
                                        U_m =     private
                                        J\_m =     private
                                        J\_s =     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_s, j_m, k, u_m)
                                        use fmin_fmax_functions
                                            real(8), intent (in) :: j_s
                                            real(8), intent (in) :: j_m
                                            real(8), intent (in) :: k
                                            real(8), intent (in) :: u_m
                                            code = j_s * -u_m
                                        end function
                                        
                                        U_m = Math.abs(U);
                                        J\_m = Math.abs(J);
                                        J\_s = Math.copySign(1.0, J);
                                        public static double code(double J_s, double J_m, double K, double U_m) {
                                        	return J_s * -U_m;
                                        }
                                        
                                        U_m = math.fabs(U)
                                        J\_m = math.fabs(J)
                                        J\_s = math.copysign(1.0, J)
                                        def code(J_s, J_m, K, U_m):
                                        	return J_s * -U_m
                                        
                                        U_m = abs(U)
                                        J\_m = abs(J)
                                        J\_s = copysign(1.0, J)
                                        function code(J_s, J_m, K, U_m)
                                        	return Float64(J_s * Float64(-U_m))
                                        end
                                        
                                        U_m = abs(U);
                                        J\_m = abs(J);
                                        J\_s = sign(J) * abs(1.0);
                                        function tmp = code(J_s, J_m, K, U_m)
                                        	tmp = J_s * -U_m;
                                        end
                                        
                                        U_m = N[Abs[U], $MachinePrecision]
                                        J\_m = N[Abs[J], $MachinePrecision]
                                        J\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[J]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
                                        code[J$95$s_, J$95$m_, K_, U$95$m_] := N[(J$95$s * (-U$95$m)), $MachinePrecision]
                                        
                                        \begin{array}{l}
                                        U_m = \left|U\right|
                                        \\
                                        J\_m = \left|J\right|
                                        \\
                                        J\_s = \mathsf{copysign}\left(1, J\right)
                                        
                                        \\
                                        J\_s \cdot \left(-U\_m\right)
                                        \end{array}
                                        
                                        Derivation
                                        1. Initial program 72.9%

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

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

                                            \[\leadsto \color{blue}{\mathsf{neg}\left(U\right)} \]
                                          2. lower-neg.f6430.5

                                            \[\leadsto \color{blue}{-U} \]
                                        5. Applied rewrites30.5%

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

                                        Reproduce

                                        ?
                                        herbie shell --seed 2025011 
                                        (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)))))