Maksimov and Kolovsky, Equation (3)

Percentage Accurate: 73.3% → 99.4%
Time: 12.4s
Alternatives: 13
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)));
}
real(8) function code(j, k, u)
    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 13 alternatives:

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

Initial Program: 73.3% 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)));
}
real(8) function code(j, k, u)
    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: 99.4% accurate, 0.3× speedup?

\[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{t\_0 \cdot \left(J \cdot 2\right)}\right)}^{2}}\\ t_2 := \cos \left(K \cdot 0.5\right)\\ \mathbf{if}\;t\_1 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_1 \leq 10^{+303}:\\ \;\;\;\;\left(-2 \cdot \left(J \cdot t\_2\right)\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{J \cdot \left(2 \cdot t\_2\right)}\right)}^{2}}\\ \mathbf{else}:\\ \;\;\;\;\left(-U\_m\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m \cdot U\_m}, -1\right)\\ \end{array} \end{array} \]
U_m = (fabs.f64 U)
(FPCore (J K U_m)
 :precision binary64
 (let* ((t_0 (cos (/ K 2.0)))
        (t_1
         (*
          (* (* -2.0 J) t_0)
          (sqrt (+ 1.0 (pow (/ U_m (* t_0 (* J 2.0))) 2.0)))))
        (t_2 (cos (* K 0.5))))
   (if (<= t_1 (- INFINITY))
     (- U_m)
     (if (<= t_1 1e+303)
       (*
        (* -2.0 (* J t_2))
        (sqrt (+ 1.0 (pow (/ U_m (* J (* 2.0 t_2))) 2.0))))
       (* (- U_m) (fma -2.0 (/ (* J J) (* U_m U_m)) -1.0))))))
U_m = fabs(U);
double code(double J, double K, double U_m) {
	double t_0 = cos((K / 2.0));
	double t_1 = ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U_m / (t_0 * (J * 2.0))), 2.0)));
	double t_2 = cos((K * 0.5));
	double tmp;
	if (t_1 <= -((double) INFINITY)) {
		tmp = -U_m;
	} else if (t_1 <= 1e+303) {
		tmp = (-2.0 * (J * t_2)) * sqrt((1.0 + pow((U_m / (J * (2.0 * t_2))), 2.0)));
	} else {
		tmp = -U_m * fma(-2.0, ((J * J) / (U_m * U_m)), -1.0);
	}
	return tmp;
}
U_m = abs(U)
function code(J, K, U_m)
	t_0 = cos(Float64(K / 2.0))
	t_1 = Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(t_0 * Float64(J * 2.0))) ^ 2.0))))
	t_2 = cos(Float64(K * 0.5))
	tmp = 0.0
	if (t_1 <= Float64(-Inf))
		tmp = Float64(-U_m);
	elseif (t_1 <= 1e+303)
		tmp = Float64(Float64(-2.0 * Float64(J * t_2)) * sqrt(Float64(1.0 + (Float64(U_m / Float64(J * Float64(2.0 * t_2))) ^ 2.0))));
	else
		tmp = Float64(Float64(-U_m) * fma(-2.0, Float64(Float64(J * J) / Float64(U_m * U_m)), -1.0));
	end
	return tmp
end
U_m = N[Abs[U], $MachinePrecision]
code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(t$95$0 * N[(J * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[Cos[N[(K * 0.5), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[t$95$1, (-Infinity)], (-U$95$m), If[LessEqual[t$95$1, 1e+303], N[(N[(-2.0 * N[(J * t$95$2), $MachinePrecision]), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(J * N[(2.0 * t$95$2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[((-U$95$m) * N[(-2.0 * N[(N[(J * J), $MachinePrecision] / N[(U$95$m * U$95$m), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]]]]]]
\begin{array}{l}
U_m = \left|U\right|

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

\mathbf{elif}\;t\_1 \leq 10^{+303}:\\
\;\;\;\;\left(-2 \cdot \left(J \cdot t\_2\right)\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{J \cdot \left(2 \cdot t\_2\right)}\right)}^{2}}\\

\mathbf{else}:\\
\;\;\;\;\left(-U\_m\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m \cdot U\_m}, -1\right)\\


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

    1. Initial program 5.6%

      \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    2. 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.f6450.3

        \[\leadsto \color{blue}{-U} \]
    5. Applied rewrites50.3%

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

    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))))) < 1e303

    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. Step-by-step derivation
      1. lift-/.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    if 1e303 < (*.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 5.6%

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

      \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    4. Step-by-step derivation
      1. lower-*.f645.0

        \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    5. Applied rewrites5.0%

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

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

        \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
      2. lower-*.f645.0

        \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
    8. Applied rewrites5.0%

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

      \[\leadsto \color{blue}{-1 \cdot \left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
    10. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \color{blue}{\mathsf{neg}\left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
      2. distribute-rgt-neg-inN/A

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

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

        \[\leadsto U \cdot \color{blue}{\left(\mathsf{neg}\left(\left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)\right)} \]
      5. sub-negN/A

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

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

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

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

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

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

        \[\leadsto U \cdot \left(\mathsf{neg}\left(\mathsf{fma}\left(-2, \frac{J \cdot J}{\color{blue}{U \cdot U}}, -1\right)\right)\right) \]
      12. lower-*.f6453.6

        \[\leadsto U \cdot \left(-\mathsf{fma}\left(-2, \frac{J \cdot J}{\color{blue}{U \cdot U}}, -1\right)\right) \]
    11. Applied rewrites53.6%

      \[\leadsto \color{blue}{U \cdot \left(-\mathsf{fma}\left(-2, \frac{J \cdot J}{U \cdot U}, -1\right)\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification88.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq -\infty:\\ \;\;\;\;-U\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq 10^{+303}:\\ \;\;\;\;\left(-2 \cdot \left(J \cdot \cos \left(K \cdot 0.5\right)\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{J \cdot \left(2 \cdot \cos \left(K \cdot 0.5\right)\right)}\right)}^{2}}\\ \mathbf{else}:\\ \;\;\;\;\left(-U\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U \cdot U}, -1\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 76.3% accurate, 0.2× speedup?

\[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{t\_0 \cdot \left(J \cdot 2\right)}\right)}^{2}}\\ t_2 := \left(-2 \cdot J\right) \cdot \cos \left(K \cdot 0.5\right)\\ \mathbf{if}\;t\_1 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_1 \leq -5 \cdot 10^{+246}:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq -5 \cdot 10^{-263}:\\ \;\;\;\;J \cdot \left(-2 \cdot \sqrt{\mathsf{fma}\left(\frac{U\_m}{J} \cdot \frac{U\_m}{J}, 0.25, 1\right)}\right)\\ \mathbf{elif}\;t\_1 \leq 10^{+303}:\\ \;\;\;\;t\_2\\ \mathbf{else}:\\ \;\;\;\;\left(-U\_m\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m \cdot U\_m}, -1\right)\\ \end{array} \end{array} \]
U_m = (fabs.f64 U)
(FPCore (J K U_m)
 :precision binary64
 (let* ((t_0 (cos (/ K 2.0)))
        (t_1
         (*
          (* (* -2.0 J) t_0)
          (sqrt (+ 1.0 (pow (/ U_m (* t_0 (* J 2.0))) 2.0)))))
        (t_2 (* (* -2.0 J) (cos (* K 0.5)))))
   (if (<= t_1 (- INFINITY))
     (- U_m)
     (if (<= t_1 -5e+246)
       t_2
       (if (<= t_1 -5e-263)
         (* J (* -2.0 (sqrt (fma (* (/ U_m J) (/ U_m J)) 0.25 1.0))))
         (if (<= t_1 1e+303)
           t_2
           (* (- U_m) (fma -2.0 (/ (* J J) (* U_m U_m)) -1.0))))))))
U_m = fabs(U);
double code(double J, double K, double U_m) {
	double t_0 = cos((K / 2.0));
	double t_1 = ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U_m / (t_0 * (J * 2.0))), 2.0)));
	double t_2 = (-2.0 * J) * cos((K * 0.5));
	double tmp;
	if (t_1 <= -((double) INFINITY)) {
		tmp = -U_m;
	} else if (t_1 <= -5e+246) {
		tmp = t_2;
	} else if (t_1 <= -5e-263) {
		tmp = J * (-2.0 * sqrt(fma(((U_m / J) * (U_m / J)), 0.25, 1.0)));
	} else if (t_1 <= 1e+303) {
		tmp = t_2;
	} else {
		tmp = -U_m * fma(-2.0, ((J * J) / (U_m * U_m)), -1.0);
	}
	return tmp;
}
U_m = abs(U)
function code(J, K, U_m)
	t_0 = cos(Float64(K / 2.0))
	t_1 = Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(t_0 * Float64(J * 2.0))) ^ 2.0))))
	t_2 = Float64(Float64(-2.0 * J) * cos(Float64(K * 0.5)))
	tmp = 0.0
	if (t_1 <= Float64(-Inf))
		tmp = Float64(-U_m);
	elseif (t_1 <= -5e+246)
		tmp = t_2;
	elseif (t_1 <= -5e-263)
		tmp = Float64(J * Float64(-2.0 * sqrt(fma(Float64(Float64(U_m / J) * Float64(U_m / J)), 0.25, 1.0))));
	elseif (t_1 <= 1e+303)
		tmp = t_2;
	else
		tmp = Float64(Float64(-U_m) * fma(-2.0, Float64(Float64(J * J) / Float64(U_m * U_m)), -1.0));
	end
	return tmp
end
U_m = N[Abs[U], $MachinePrecision]
code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(t$95$0 * N[(J * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(-2.0 * J), $MachinePrecision] * N[Cos[N[(K * 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, (-Infinity)], (-U$95$m), If[LessEqual[t$95$1, -5e+246], t$95$2, If[LessEqual[t$95$1, -5e-263], N[(J * N[(-2.0 * N[Sqrt[N[(N[(N[(U$95$m / J), $MachinePrecision] * N[(U$95$m / J), $MachinePrecision]), $MachinePrecision] * 0.25 + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$1, 1e+303], t$95$2, N[((-U$95$m) * N[(-2.0 * N[(N[(J * J), $MachinePrecision] / N[(U$95$m * U$95$m), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]]]]]]]]
\begin{array}{l}
U_m = \left|U\right|

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

\mathbf{elif}\;t\_1 \leq -5 \cdot 10^{+246}:\\
\;\;\;\;t\_2\\

\mathbf{elif}\;t\_1 \leq -5 \cdot 10^{-263}:\\
\;\;\;\;J \cdot \left(-2 \cdot \sqrt{\mathsf{fma}\left(\frac{U\_m}{J} \cdot \frac{U\_m}{J}, 0.25, 1\right)}\right)\\

\mathbf{elif}\;t\_1 \leq 10^{+303}:\\
\;\;\;\;t\_2\\

\mathbf{else}:\\
\;\;\;\;\left(-U\_m\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m \cdot U\_m}, -1\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 4 regimes
  2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -inf.0

    1. Initial program 5.6%

      \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    2. 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.f6450.3

        \[\leadsto \color{blue}{-U} \]
    5. Applied rewrites50.3%

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

    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))))) < -4.99999999999999976e246 or -5.00000000000000006e-263 < (*.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))))) < 1e303

    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

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

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

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

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

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

        \[\leadsto \cos \color{blue}{\left(\frac{1}{2} \cdot K\right)} \cdot \left(-2 \cdot J\right) \]
      6. lower-*.f6476.0

        \[\leadsto \cos \left(0.5 \cdot K\right) \cdot \color{blue}{\left(-2 \cdot J\right)} \]
    5. Applied rewrites76.0%

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

    if -4.99999999999999976e246 < (*.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))))) < -5.00000000000000006e-263

    1. Initial program 99.7%

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

      \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    4. Step-by-step derivation
      1. lower-*.f6455.2

        \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    5. Applied rewrites55.2%

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

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

        \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
      2. lower-*.f6461.5

        \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
    8. Applied rewrites61.5%

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \color{blue}{\left(\sqrt{1 + {\left(\frac{U}{J \cdot 2}\right)}^{2}} \cdot -2\right) \cdot J} \]
    10. Applied rewrites61.5%

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

    if 1e303 < (*.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 5.6%

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

      \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    4. Step-by-step derivation
      1. lower-*.f645.0

        \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    5. Applied rewrites5.0%

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

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

        \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
      2. lower-*.f645.0

        \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
    8. Applied rewrites5.0%

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

      \[\leadsto \color{blue}{-1 \cdot \left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
    10. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \color{blue}{\mathsf{neg}\left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
      2. distribute-rgt-neg-inN/A

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

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

        \[\leadsto U \cdot \color{blue}{\left(\mathsf{neg}\left(\left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)\right)} \]
      5. sub-negN/A

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

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

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

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

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

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

        \[\leadsto U \cdot \left(\mathsf{neg}\left(\mathsf{fma}\left(-2, \frac{J \cdot J}{\color{blue}{U \cdot U}}, -1\right)\right)\right) \]
      12. lower-*.f6453.6

        \[\leadsto U \cdot \left(-\mathsf{fma}\left(-2, \frac{J \cdot J}{\color{blue}{U \cdot U}}, -1\right)\right) \]
    11. Applied rewrites53.6%

      \[\leadsto \color{blue}{U \cdot \left(-\mathsf{fma}\left(-2, \frac{J \cdot J}{U \cdot U}, -1\right)\right)} \]
  3. Recombined 4 regimes into one program.
  4. Final simplification66.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq -\infty:\\ \;\;\;\;-U\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq -5 \cdot 10^{+246}:\\ \;\;\;\;\left(-2 \cdot J\right) \cdot \cos \left(K \cdot 0.5\right)\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq -5 \cdot 10^{-263}:\\ \;\;\;\;J \cdot \left(-2 \cdot \sqrt{\mathsf{fma}\left(\frac{U}{J} \cdot \frac{U}{J}, 0.25, 1\right)}\right)\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq 10^{+303}:\\ \;\;\;\;\left(-2 \cdot J\right) \cdot \cos \left(K \cdot 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\left(-U\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U \cdot U}, -1\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 55.6% accurate, 0.2× speedup?

\[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{t\_0 \cdot \left(J \cdot 2\right)}\right)}^{2}}\\ \mathbf{if}\;t\_1 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_1 \leq -1 \cdot 10^{+156}:\\ \;\;\;\;-2 \cdot J\\ \mathbf{elif}\;t\_1 \leq -2 \cdot 10^{-152}:\\ \;\;\;\;\left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(0.25, \frac{U\_m \cdot U\_m}{J \cdot J}, 1\right)}\\ \mathbf{elif}\;t\_1 \leq 10^{-150}:\\ \;\;\;\;-U\_m\\ \mathbf{else}:\\ \;\;\;\;\left(-U\_m\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m \cdot U\_m}, -1\right)\\ \end{array} \end{array} \]
U_m = (fabs.f64 U)
(FPCore (J K U_m)
 :precision binary64
 (let* ((t_0 (cos (/ K 2.0)))
        (t_1
         (*
          (* (* -2.0 J) t_0)
          (sqrt (+ 1.0 (pow (/ U_m (* t_0 (* J 2.0))) 2.0))))))
   (if (<= t_1 (- INFINITY))
     (- U_m)
     (if (<= t_1 -1e+156)
       (* -2.0 J)
       (if (<= t_1 -2e-152)
         (* (* -2.0 J) (sqrt (fma 0.25 (/ (* U_m U_m) (* J J)) 1.0)))
         (if (<= t_1 1e-150)
           (- U_m)
           (* (- U_m) (fma -2.0 (/ (* J J) (* U_m U_m)) -1.0))))))))
U_m = fabs(U);
double code(double J, double K, double U_m) {
	double t_0 = cos((K / 2.0));
	double t_1 = ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U_m / (t_0 * (J * 2.0))), 2.0)));
	double tmp;
	if (t_1 <= -((double) INFINITY)) {
		tmp = -U_m;
	} else if (t_1 <= -1e+156) {
		tmp = -2.0 * J;
	} else if (t_1 <= -2e-152) {
		tmp = (-2.0 * J) * sqrt(fma(0.25, ((U_m * U_m) / (J * J)), 1.0));
	} else if (t_1 <= 1e-150) {
		tmp = -U_m;
	} else {
		tmp = -U_m * fma(-2.0, ((J * J) / (U_m * U_m)), -1.0);
	}
	return tmp;
}
U_m = abs(U)
function code(J, K, U_m)
	t_0 = cos(Float64(K / 2.0))
	t_1 = Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(t_0 * Float64(J * 2.0))) ^ 2.0))))
	tmp = 0.0
	if (t_1 <= Float64(-Inf))
		tmp = Float64(-U_m);
	elseif (t_1 <= -1e+156)
		tmp = Float64(-2.0 * J);
	elseif (t_1 <= -2e-152)
		tmp = Float64(Float64(-2.0 * J) * sqrt(fma(0.25, Float64(Float64(U_m * U_m) / Float64(J * J)), 1.0)));
	elseif (t_1 <= 1e-150)
		tmp = Float64(-U_m);
	else
		tmp = Float64(Float64(-U_m) * fma(-2.0, Float64(Float64(J * J) / Float64(U_m * U_m)), -1.0));
	end
	return tmp
end
U_m = N[Abs[U], $MachinePrecision]
code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(t$95$0 * N[(J * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, (-Infinity)], (-U$95$m), If[LessEqual[t$95$1, -1e+156], N[(-2.0 * J), $MachinePrecision], If[LessEqual[t$95$1, -2e-152], N[(N[(-2.0 * J), $MachinePrecision] * N[Sqrt[N[(0.25 * N[(N[(U$95$m * U$95$m), $MachinePrecision] / N[(J * J), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$1, 1e-150], (-U$95$m), N[((-U$95$m) * N[(-2.0 * N[(N[(J * J), $MachinePrecision] / N[(U$95$m * U$95$m), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]]]]]]]
\begin{array}{l}
U_m = \left|U\right|

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

\mathbf{elif}\;t\_1 \leq -1 \cdot 10^{+156}:\\
\;\;\;\;-2 \cdot J\\

\mathbf{elif}\;t\_1 \leq -2 \cdot 10^{-152}:\\
\;\;\;\;\left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(0.25, \frac{U\_m \cdot U\_m}{J \cdot J}, 1\right)}\\

\mathbf{elif}\;t\_1 \leq 10^{-150}:\\
\;\;\;\;-U\_m\\

\mathbf{else}:\\
\;\;\;\;\left(-U\_m\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m \cdot U\_m}, -1\right)\\


\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 or -2.00000000000000013e-152 < (*.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))))) < 1.00000000000000001e-150

    1. Initial program 39.6%

      \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    2. 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.f6439.8

        \[\leadsto \color{blue}{-U} \]
    5. Applied rewrites39.8%

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

    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))))) < -9.9999999999999998e155

    1. Initial program 99.7%

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

      \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    4. Step-by-step derivation
      1. lower-*.f6443.8

        \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    5. Applied rewrites43.8%

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

      \[\leadsto \color{blue}{-2 \cdot J} \]
    7. Step-by-step derivation
      1. lower-*.f6430.2

        \[\leadsto \color{blue}{-2 \cdot J} \]
    8. Applied rewrites30.2%

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

    if -9.9999999999999998e155 < (*.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))))) < -2.00000000000000013e-152

    1. Initial program 99.7%

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

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

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

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

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

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

        \[\leadsto \sqrt{\mathsf{fma}\left(\frac{1}{4}, \frac{U \cdot U}{\color{blue}{J \cdot J}}, 1\right)} \cdot \left(-2 \cdot J\right) \]
      12. lower-*.f6455.7

        \[\leadsto \sqrt{\mathsf{fma}\left(0.25, \frac{U \cdot U}{J \cdot J}, 1\right)} \cdot \color{blue}{\left(-2 \cdot J\right)} \]
    5. Applied rewrites55.7%

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

    if 1.00000000000000001e-150 < (*.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 76.8%

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

      \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    4. Step-by-step derivation
      1. lower-*.f6444.8

        \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    5. Applied rewrites44.8%

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

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

        \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
      2. lower-*.f6447.9

        \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
    8. Applied rewrites47.9%

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

      \[\leadsto \color{blue}{-1 \cdot \left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
    10. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \color{blue}{\mathsf{neg}\left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
      2. distribute-rgt-neg-inN/A

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

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

        \[\leadsto U \cdot \color{blue}{\left(\mathsf{neg}\left(\left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)\right)} \]
      5. sub-negN/A

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

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

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

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

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

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

        \[\leadsto U \cdot \left(\mathsf{neg}\left(\mathsf{fma}\left(-2, \frac{J \cdot J}{\color{blue}{U \cdot U}}, -1\right)\right)\right) \]
      12. lower-*.f6425.9

        \[\leadsto U \cdot \left(-\mathsf{fma}\left(-2, \frac{J \cdot J}{\color{blue}{U \cdot U}}, -1\right)\right) \]
    11. Applied rewrites25.9%

      \[\leadsto \color{blue}{U \cdot \left(-\mathsf{fma}\left(-2, \frac{J \cdot J}{U \cdot U}, -1\right)\right)} \]
  3. Recombined 4 regimes into one program.
  4. Final simplification34.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq -\infty:\\ \;\;\;\;-U\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq -1 \cdot 10^{+156}:\\ \;\;\;\;-2 \cdot J\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq -2 \cdot 10^{-152}:\\ \;\;\;\;\left(-2 \cdot J\right) \cdot \sqrt{\mathsf{fma}\left(0.25, \frac{U \cdot U}{J \cdot J}, 1\right)}\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq 10^{-150}:\\ \;\;\;\;-U\\ \mathbf{else}:\\ \;\;\;\;\left(-U\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U \cdot U}, -1\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 91.4% accurate, 0.3× speedup?

\[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(-2 \cdot J\right) \cdot t\_0\\ t_2 := t\_1 \cdot \sqrt{1 + {\left(\frac{U\_m}{t\_0 \cdot \left(J \cdot 2\right)}\right)}^{2}}\\ \mathbf{if}\;t\_2 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_2 \leq 5 \cdot 10^{-82}:\\ \;\;\;\;t\_1 \cdot \sqrt{1 + {\left(\frac{U\_m}{J \cdot 2}\right)}^{2}}\\ \mathbf{elif}\;t\_2 \leq 10^{+303}:\\ \;\;\;\;\left(-2 \cdot \left(J \cdot \cos \left(K \cdot 0.5\right)\right)\right) \cdot \sqrt{\mathsf{fma}\left(U\_m, \frac{U\_m}{\left(J \cdot 2\right) \cdot \mathsf{fma}\left(J, \cos K, J\right)}, 1\right)}\\ \mathbf{else}:\\ \;\;\;\;\left(-U\_m\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m \cdot U\_m}, -1\right)\\ \end{array} \end{array} \]
U_m = (fabs.f64 U)
(FPCore (J K U_m)
 :precision binary64
 (let* ((t_0 (cos (/ K 2.0)))
        (t_1 (* (* -2.0 J) t_0))
        (t_2 (* t_1 (sqrt (+ 1.0 (pow (/ U_m (* t_0 (* J 2.0))) 2.0))))))
   (if (<= t_2 (- INFINITY))
     (- U_m)
     (if (<= t_2 5e-82)
       (* t_1 (sqrt (+ 1.0 (pow (/ U_m (* J 2.0)) 2.0))))
       (if (<= t_2 1e+303)
         (*
          (* -2.0 (* J (cos (* K 0.5))))
          (sqrt (fma U_m (/ U_m (* (* J 2.0) (fma J (cos K) J))) 1.0)))
         (* (- U_m) (fma -2.0 (/ (* J J) (* U_m U_m)) -1.0)))))))
U_m = fabs(U);
double code(double J, double K, double U_m) {
	double t_0 = cos((K / 2.0));
	double t_1 = (-2.0 * J) * t_0;
	double t_2 = t_1 * sqrt((1.0 + pow((U_m / (t_0 * (J * 2.0))), 2.0)));
	double tmp;
	if (t_2 <= -((double) INFINITY)) {
		tmp = -U_m;
	} else if (t_2 <= 5e-82) {
		tmp = t_1 * sqrt((1.0 + pow((U_m / (J * 2.0)), 2.0)));
	} else if (t_2 <= 1e+303) {
		tmp = (-2.0 * (J * cos((K * 0.5)))) * sqrt(fma(U_m, (U_m / ((J * 2.0) * fma(J, cos(K), J))), 1.0));
	} else {
		tmp = -U_m * fma(-2.0, ((J * J) / (U_m * U_m)), -1.0);
	}
	return tmp;
}
U_m = abs(U)
function code(J, K, U_m)
	t_0 = cos(Float64(K / 2.0))
	t_1 = Float64(Float64(-2.0 * J) * t_0)
	t_2 = Float64(t_1 * sqrt(Float64(1.0 + (Float64(U_m / Float64(t_0 * Float64(J * 2.0))) ^ 2.0))))
	tmp = 0.0
	if (t_2 <= Float64(-Inf))
		tmp = Float64(-U_m);
	elseif (t_2 <= 5e-82)
		tmp = Float64(t_1 * sqrt(Float64(1.0 + (Float64(U_m / Float64(J * 2.0)) ^ 2.0))));
	elseif (t_2 <= 1e+303)
		tmp = Float64(Float64(-2.0 * Float64(J * cos(Float64(K * 0.5)))) * sqrt(fma(U_m, Float64(U_m / Float64(Float64(J * 2.0) * fma(J, cos(K), J))), 1.0)));
	else
		tmp = Float64(Float64(-U_m) * fma(-2.0, Float64(Float64(J * J) / Float64(U_m * U_m)), -1.0));
	end
	return tmp
end
U_m = N[Abs[U], $MachinePrecision]
code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$1 * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(t$95$0 * N[(J * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$2, (-Infinity)], (-U$95$m), If[LessEqual[t$95$2, 5e-82], N[(t$95$1 * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(J * 2.0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$2, 1e+303], N[(N[(-2.0 * N[(J * N[Cos[N[(K * 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Sqrt[N[(U$95$m * N[(U$95$m / N[(N[(J * 2.0), $MachinePrecision] * N[(J * N[Cos[K], $MachinePrecision] + J), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[((-U$95$m) * N[(-2.0 * N[(N[(J * J), $MachinePrecision] / N[(U$95$m * U$95$m), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]]]]]]]
\begin{array}{l}
U_m = \left|U\right|

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

\mathbf{elif}\;t\_2 \leq 5 \cdot 10^{-82}:\\
\;\;\;\;t\_1 \cdot \sqrt{1 + {\left(\frac{U\_m}{J \cdot 2}\right)}^{2}}\\

\mathbf{elif}\;t\_2 \leq 10^{+303}:\\
\;\;\;\;\left(-2 \cdot \left(J \cdot \cos \left(K \cdot 0.5\right)\right)\right) \cdot \sqrt{\mathsf{fma}\left(U\_m, \frac{U\_m}{\left(J \cdot 2\right) \cdot \mathsf{fma}\left(J, \cos K, J\right)}, 1\right)}\\

\mathbf{else}:\\
\;\;\;\;\left(-U\_m\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m \cdot U\_m}, -1\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 4 regimes
  2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -inf.0

    1. Initial program 5.6%

      \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    2. 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.f6450.3

        \[\leadsto \color{blue}{-U} \]
    5. Applied rewrites50.3%

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

    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))))) < 4.9999999999999998e-82

    1. Initial program 99.7%

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

      \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \color{blue}{1}}\right)}^{2}} \]
    4. Step-by-step derivation
      1. Applied rewrites85.1%

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

      if 4.9999999999999998e-82 < (*.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))))) < 1e303

      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. Step-by-step derivation
        1. lift-/.f64N/A

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \color{blue}{\left(\left(J \cdot \cos \left(K \cdot 0.5\right)\right) \cdot -2\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      5. Applied rewrites98.2%

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

      if 1e303 < (*.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 5.6%

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

        \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      4. Step-by-step derivation
        1. lower-*.f645.0

          \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      5. Applied rewrites5.0%

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

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

          \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
        2. lower-*.f645.0

          \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
      8. Applied rewrites5.0%

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

        \[\leadsto \color{blue}{-1 \cdot \left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
      10. Step-by-step derivation
        1. mul-1-negN/A

          \[\leadsto \color{blue}{\mathsf{neg}\left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
        2. distribute-rgt-neg-inN/A

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

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

          \[\leadsto U \cdot \color{blue}{\left(\mathsf{neg}\left(\left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)\right)} \]
        5. sub-negN/A

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

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

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

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

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

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

          \[\leadsto U \cdot \left(\mathsf{neg}\left(\mathsf{fma}\left(-2, \frac{J \cdot J}{\color{blue}{U \cdot U}}, -1\right)\right)\right) \]
        12. lower-*.f6453.6

          \[\leadsto U \cdot \left(-\mathsf{fma}\left(-2, \frac{J \cdot J}{\color{blue}{U \cdot U}}, -1\right)\right) \]
      11. Applied rewrites53.6%

        \[\leadsto \color{blue}{U \cdot \left(-\mathsf{fma}\left(-2, \frac{J \cdot J}{U \cdot U}, -1\right)\right)} \]
    5. Recombined 4 regimes into one program.
    6. Final simplification81.5%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq -\infty:\\ \;\;\;\;-U\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq 5 \cdot 10^{-82}:\\ \;\;\;\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{J \cdot 2}\right)}^{2}}\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq 10^{+303}:\\ \;\;\;\;\left(-2 \cdot \left(J \cdot \cos \left(K \cdot 0.5\right)\right)\right) \cdot \sqrt{\mathsf{fma}\left(U, \frac{U}{\left(J \cdot 2\right) \cdot \mathsf{fma}\left(J, \cos K, J\right)}, 1\right)}\\ \mathbf{else}:\\ \;\;\;\;\left(-U\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U \cdot U}, -1\right)\\ \end{array} \]
    7. Add Preprocessing

    Alternative 5: 53.2% accurate, 0.3× speedup?

    \[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{t\_0 \cdot \left(J \cdot 2\right)}\right)}^{2}}\\ \mathbf{if}\;t\_1 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_1 \leq -1 \cdot 10^{+18}:\\ \;\;\;\;-2 \cdot J\\ \mathbf{elif}\;t\_1 \leq 10^{-150}:\\ \;\;\;\;\mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m}, -U\_m\right)\\ \mathbf{else}:\\ \;\;\;\;\left(-U\_m\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m \cdot U\_m}, -1\right)\\ \end{array} \end{array} \]
    U_m = (fabs.f64 U)
    (FPCore (J K U_m)
     :precision binary64
     (let* ((t_0 (cos (/ K 2.0)))
            (t_1
             (*
              (* (* -2.0 J) t_0)
              (sqrt (+ 1.0 (pow (/ U_m (* t_0 (* J 2.0))) 2.0))))))
       (if (<= t_1 (- INFINITY))
         (- U_m)
         (if (<= t_1 -1e+18)
           (* -2.0 J)
           (if (<= t_1 1e-150)
             (fma -2.0 (/ (* J J) U_m) (- U_m))
             (* (- U_m) (fma -2.0 (/ (* J J) (* U_m U_m)) -1.0)))))))
    U_m = fabs(U);
    double code(double J, double K, double U_m) {
    	double t_0 = cos((K / 2.0));
    	double t_1 = ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U_m / (t_0 * (J * 2.0))), 2.0)));
    	double tmp;
    	if (t_1 <= -((double) INFINITY)) {
    		tmp = -U_m;
    	} else if (t_1 <= -1e+18) {
    		tmp = -2.0 * J;
    	} else if (t_1 <= 1e-150) {
    		tmp = fma(-2.0, ((J * J) / U_m), -U_m);
    	} else {
    		tmp = -U_m * fma(-2.0, ((J * J) / (U_m * U_m)), -1.0);
    	}
    	return tmp;
    }
    
    U_m = abs(U)
    function code(J, K, U_m)
    	t_0 = cos(Float64(K / 2.0))
    	t_1 = Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(t_0 * Float64(J * 2.0))) ^ 2.0))))
    	tmp = 0.0
    	if (t_1 <= Float64(-Inf))
    		tmp = Float64(-U_m);
    	elseif (t_1 <= -1e+18)
    		tmp = Float64(-2.0 * J);
    	elseif (t_1 <= 1e-150)
    		tmp = fma(-2.0, Float64(Float64(J * J) / U_m), Float64(-U_m));
    	else
    		tmp = Float64(Float64(-U_m) * fma(-2.0, Float64(Float64(J * J) / Float64(U_m * U_m)), -1.0));
    	end
    	return tmp
    end
    
    U_m = N[Abs[U], $MachinePrecision]
    code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(t$95$0 * N[(J * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, (-Infinity)], (-U$95$m), If[LessEqual[t$95$1, -1e+18], N[(-2.0 * J), $MachinePrecision], If[LessEqual[t$95$1, 1e-150], N[(-2.0 * N[(N[(J * J), $MachinePrecision] / U$95$m), $MachinePrecision] + (-U$95$m)), $MachinePrecision], N[((-U$95$m) * N[(-2.0 * N[(N[(J * J), $MachinePrecision] / N[(U$95$m * U$95$m), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]]]]]]
    
    \begin{array}{l}
    U_m = \left|U\right|
    
    \\
    \begin{array}{l}
    t_0 := \cos \left(\frac{K}{2}\right)\\
    t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{t\_0 \cdot \left(J \cdot 2\right)}\right)}^{2}}\\
    \mathbf{if}\;t\_1 \leq -\infty:\\
    \;\;\;\;-U\_m\\
    
    \mathbf{elif}\;t\_1 \leq -1 \cdot 10^{+18}:\\
    \;\;\;\;-2 \cdot J\\
    
    \mathbf{elif}\;t\_1 \leq 10^{-150}:\\
    \;\;\;\;\mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m}, -U\_m\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\left(-U\_m\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m \cdot U\_m}, -1\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 4 regimes
    2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -inf.0

      1. Initial program 5.6%

        \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      2. 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.f6450.3

          \[\leadsto \color{blue}{-U} \]
      5. Applied rewrites50.3%

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

      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))))) < -1e18

      1. Initial program 99.7%

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

        \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      4. Step-by-step derivation
        1. lower-*.f6449.1

          \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      5. Applied rewrites49.1%

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

        \[\leadsto \color{blue}{-2 \cdot J} \]
      7. Step-by-step derivation
        1. lower-*.f6435.5

          \[\leadsto \color{blue}{-2 \cdot J} \]
      8. Applied rewrites35.5%

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

      if -1e18 < (*.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))))) < 1.00000000000000001e-150

      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 0

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

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

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

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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \mathsf{fma}\left(\frac{{\cos \left(\frac{1}{2} \cdot K\right)}^{2}}{U}, -2 \cdot \left(J \cdot J\right), \color{blue}{\mathsf{neg}\left(U\right)}\right) \]
        15. lower-neg.f6415.5

          \[\leadsto \mathsf{fma}\left(\frac{{\cos \left(0.5 \cdot K\right)}^{2}}{U}, -2 \cdot \left(J \cdot J\right), \color{blue}{-U}\right) \]
      5. Applied rewrites15.5%

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

        \[\leadsto \color{blue}{-2 \cdot \frac{{J}^{2}}{U} - U} \]
      7. Step-by-step derivation
        1. sub-negN/A

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

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

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

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

          \[\leadsto \mathsf{fma}\left(-2, \frac{\color{blue}{J \cdot J}}{U}, \mathsf{neg}\left(U\right)\right) \]
        6. lower-neg.f6415.5

          \[\leadsto \mathsf{fma}\left(-2, \frac{J \cdot J}{U}, \color{blue}{-U}\right) \]
      8. Applied rewrites15.5%

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

      if 1.00000000000000001e-150 < (*.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 76.8%

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

        \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      4. Step-by-step derivation
        1. lower-*.f6444.8

          \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      5. Applied rewrites44.8%

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

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

          \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
        2. lower-*.f6447.9

          \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
      8. Applied rewrites47.9%

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

        \[\leadsto \color{blue}{-1 \cdot \left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
      10. Step-by-step derivation
        1. mul-1-negN/A

          \[\leadsto \color{blue}{\mathsf{neg}\left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
        2. distribute-rgt-neg-inN/A

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

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

          \[\leadsto U \cdot \color{blue}{\left(\mathsf{neg}\left(\left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)\right)} \]
        5. sub-negN/A

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

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

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

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

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

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

          \[\leadsto U \cdot \left(\mathsf{neg}\left(\mathsf{fma}\left(-2, \frac{J \cdot J}{\color{blue}{U \cdot U}}, -1\right)\right)\right) \]
        12. lower-*.f6425.9

          \[\leadsto U \cdot \left(-\mathsf{fma}\left(-2, \frac{J \cdot J}{\color{blue}{U \cdot U}}, -1\right)\right) \]
      11. Applied rewrites25.9%

        \[\leadsto \color{blue}{U \cdot \left(-\mathsf{fma}\left(-2, \frac{J \cdot J}{U \cdot U}, -1\right)\right)} \]
    3. Recombined 4 regimes into one program.
    4. Final simplification29.5%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq -\infty:\\ \;\;\;\;-U\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq -1 \cdot 10^{+18}:\\ \;\;\;\;-2 \cdot J\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq 10^{-150}:\\ \;\;\;\;\mathsf{fma}\left(-2, \frac{J \cdot J}{U}, -U\right)\\ \mathbf{else}:\\ \;\;\;\;\left(-U\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U \cdot U}, -1\right)\\ \end{array} \]
    5. Add Preprocessing

    Alternative 6: 50.3% accurate, 0.3× speedup?

    \[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{t\_0 \cdot \left(J \cdot 2\right)}\right)}^{2}}\\ \mathbf{if}\;t\_1 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_1 \leq -1 \cdot 10^{+18}:\\ \;\;\;\;-2 \cdot J\\ \mathbf{elif}\;t\_1 \leq -5 \cdot 10^{-263}:\\ \;\;\;\;\mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m}, -U\_m\right)\\ \mathbf{else}:\\ \;\;\;\;\left(-2 \cdot J\right) \cdot \left(\frac{U\_m}{J} \cdot -0.5\right)\\ \end{array} \end{array} \]
    U_m = (fabs.f64 U)
    (FPCore (J K U_m)
     :precision binary64
     (let* ((t_0 (cos (/ K 2.0)))
            (t_1
             (*
              (* (* -2.0 J) t_0)
              (sqrt (+ 1.0 (pow (/ U_m (* t_0 (* J 2.0))) 2.0))))))
       (if (<= t_1 (- INFINITY))
         (- U_m)
         (if (<= t_1 -1e+18)
           (* -2.0 J)
           (if (<= t_1 -5e-263)
             (fma -2.0 (/ (* J J) U_m) (- U_m))
             (* (* -2.0 J) (* (/ U_m J) -0.5)))))))
    U_m = fabs(U);
    double code(double J, double K, double U_m) {
    	double t_0 = cos((K / 2.0));
    	double t_1 = ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U_m / (t_0 * (J * 2.0))), 2.0)));
    	double tmp;
    	if (t_1 <= -((double) INFINITY)) {
    		tmp = -U_m;
    	} else if (t_1 <= -1e+18) {
    		tmp = -2.0 * J;
    	} else if (t_1 <= -5e-263) {
    		tmp = fma(-2.0, ((J * J) / U_m), -U_m);
    	} else {
    		tmp = (-2.0 * J) * ((U_m / J) * -0.5);
    	}
    	return tmp;
    }
    
    U_m = abs(U)
    function code(J, K, U_m)
    	t_0 = cos(Float64(K / 2.0))
    	t_1 = Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(t_0 * Float64(J * 2.0))) ^ 2.0))))
    	tmp = 0.0
    	if (t_1 <= Float64(-Inf))
    		tmp = Float64(-U_m);
    	elseif (t_1 <= -1e+18)
    		tmp = Float64(-2.0 * J);
    	elseif (t_1 <= -5e-263)
    		tmp = fma(-2.0, Float64(Float64(J * J) / U_m), Float64(-U_m));
    	else
    		tmp = Float64(Float64(-2.0 * J) * Float64(Float64(U_m / J) * -0.5));
    	end
    	return tmp
    end
    
    U_m = N[Abs[U], $MachinePrecision]
    code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(t$95$0 * N[(J * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, (-Infinity)], (-U$95$m), If[LessEqual[t$95$1, -1e+18], N[(-2.0 * J), $MachinePrecision], If[LessEqual[t$95$1, -5e-263], N[(-2.0 * N[(N[(J * J), $MachinePrecision] / U$95$m), $MachinePrecision] + (-U$95$m)), $MachinePrecision], N[(N[(-2.0 * J), $MachinePrecision] * N[(N[(U$95$m / J), $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision]]]]]]
    
    \begin{array}{l}
    U_m = \left|U\right|
    
    \\
    \begin{array}{l}
    t_0 := \cos \left(\frac{K}{2}\right)\\
    t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{t\_0 \cdot \left(J \cdot 2\right)}\right)}^{2}}\\
    \mathbf{if}\;t\_1 \leq -\infty:\\
    \;\;\;\;-U\_m\\
    
    \mathbf{elif}\;t\_1 \leq -1 \cdot 10^{+18}:\\
    \;\;\;\;-2 \cdot J\\
    
    \mathbf{elif}\;t\_1 \leq -5 \cdot 10^{-263}:\\
    \;\;\;\;\mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m}, -U\_m\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\left(-2 \cdot J\right) \cdot \left(\frac{U\_m}{J} \cdot -0.5\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 4 regimes
    2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -inf.0

      1. Initial program 5.6%

        \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      2. 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.f6450.3

          \[\leadsto \color{blue}{-U} \]
      5. Applied rewrites50.3%

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

      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))))) < -1e18

      1. Initial program 99.7%

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

        \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      4. Step-by-step derivation
        1. lower-*.f6449.1

          \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      5. Applied rewrites49.1%

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

        \[\leadsto \color{blue}{-2 \cdot J} \]
      7. Step-by-step derivation
        1. lower-*.f6435.5

          \[\leadsto \color{blue}{-2 \cdot J} \]
      8. Applied rewrites35.5%

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

      if -1e18 < (*.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))))) < -5.00000000000000006e-263

      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 0

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

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

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

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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \mathsf{fma}\left(\frac{{\cos \left(\frac{1}{2} \cdot K\right)}^{2}}{U}, -2 \cdot \left(J \cdot J\right), \color{blue}{\mathsf{neg}\left(U\right)}\right) \]
        15. lower-neg.f6418.3

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

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

        \[\leadsto \color{blue}{-2 \cdot \frac{{J}^{2}}{U} - U} \]
      7. Step-by-step derivation
        1. sub-negN/A

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

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

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

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

          \[\leadsto \mathsf{fma}\left(-2, \frac{\color{blue}{J \cdot J}}{U}, \mathsf{neg}\left(U\right)\right) \]
        6. lower-neg.f6418.3

          \[\leadsto \mathsf{fma}\left(-2, \frac{J \cdot J}{U}, \color{blue}{-U}\right) \]
      8. Applied rewrites18.3%

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

      if -5.00000000000000006e-263 < (*.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 78.2%

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

        \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      4. Step-by-step derivation
        1. lower-*.f6445.5

          \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      5. Applied rewrites45.5%

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

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

          \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
        2. lower-*.f6449.0

          \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
      8. Applied rewrites49.0%

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

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

          \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\left(\frac{-1}{2} \cdot \frac{U}{J}\right)} \]
        2. lower-/.f6422.5

          \[\leadsto \left(-2 \cdot J\right) \cdot \left(-0.5 \cdot \color{blue}{\frac{U}{J}}\right) \]
      11. Applied rewrites22.5%

        \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\left(-0.5 \cdot \frac{U}{J}\right)} \]
    3. Recombined 4 regimes into one program.
    4. Final simplification28.4%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq -\infty:\\ \;\;\;\;-U\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq -1 \cdot 10^{+18}:\\ \;\;\;\;-2 \cdot J\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq -5 \cdot 10^{-263}:\\ \;\;\;\;\mathsf{fma}\left(-2, \frac{J \cdot J}{U}, -U\right)\\ \mathbf{else}:\\ \;\;\;\;\left(-2 \cdot J\right) \cdot \left(\frac{U}{J} \cdot -0.5\right)\\ \end{array} \]
    5. Add Preprocessing

    Alternative 7: 99.2% accurate, 0.4× speedup?

    \[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{t\_0 \cdot \left(J \cdot 2\right)}\right)}^{2}}\\ \mathbf{if}\;t\_1 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_1 \leq 10^{+303}:\\ \;\;\;\;\left(-2 \cdot \left(J \cdot \cos \left(K \cdot 0.5\right)\right)\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U\_m}{\mathsf{fma}\left(J, \cos K, J\right)}, \frac{U\_m}{J \cdot 2}, 1\right)}\\ \mathbf{else}:\\ \;\;\;\;\left(-U\_m\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m \cdot U\_m}, -1\right)\\ \end{array} \end{array} \]
    U_m = (fabs.f64 U)
    (FPCore (J K U_m)
     :precision binary64
     (let* ((t_0 (cos (/ K 2.0)))
            (t_1
             (*
              (* (* -2.0 J) t_0)
              (sqrt (+ 1.0 (pow (/ U_m (* t_0 (* J 2.0))) 2.0))))))
       (if (<= t_1 (- INFINITY))
         (- U_m)
         (if (<= t_1 1e+303)
           (*
            (* -2.0 (* J (cos (* K 0.5))))
            (sqrt (fma (/ U_m (fma J (cos K) J)) (/ U_m (* J 2.0)) 1.0)))
           (* (- U_m) (fma -2.0 (/ (* J J) (* U_m U_m)) -1.0))))))
    U_m = fabs(U);
    double code(double J, double K, double U_m) {
    	double t_0 = cos((K / 2.0));
    	double t_1 = ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U_m / (t_0 * (J * 2.0))), 2.0)));
    	double tmp;
    	if (t_1 <= -((double) INFINITY)) {
    		tmp = -U_m;
    	} else if (t_1 <= 1e+303) {
    		tmp = (-2.0 * (J * cos((K * 0.5)))) * sqrt(fma((U_m / fma(J, cos(K), J)), (U_m / (J * 2.0)), 1.0));
    	} else {
    		tmp = -U_m * fma(-2.0, ((J * J) / (U_m * U_m)), -1.0);
    	}
    	return tmp;
    }
    
    U_m = abs(U)
    function code(J, K, U_m)
    	t_0 = cos(Float64(K / 2.0))
    	t_1 = Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(t_0 * Float64(J * 2.0))) ^ 2.0))))
    	tmp = 0.0
    	if (t_1 <= Float64(-Inf))
    		tmp = Float64(-U_m);
    	elseif (t_1 <= 1e+303)
    		tmp = Float64(Float64(-2.0 * Float64(J * cos(Float64(K * 0.5)))) * sqrt(fma(Float64(U_m / fma(J, cos(K), J)), Float64(U_m / Float64(J * 2.0)), 1.0)));
    	else
    		tmp = Float64(Float64(-U_m) * fma(-2.0, Float64(Float64(J * J) / Float64(U_m * U_m)), -1.0));
    	end
    	return tmp
    end
    
    U_m = N[Abs[U], $MachinePrecision]
    code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(t$95$0 * N[(J * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, (-Infinity)], (-U$95$m), If[LessEqual[t$95$1, 1e+303], N[(N[(-2.0 * N[(J * N[Cos[N[(K * 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Sqrt[N[(N[(U$95$m / N[(J * N[Cos[K], $MachinePrecision] + J), $MachinePrecision]), $MachinePrecision] * N[(U$95$m / N[(J * 2.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[((-U$95$m) * N[(-2.0 * N[(N[(J * J), $MachinePrecision] / N[(U$95$m * U$95$m), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]]]]]
    
    \begin{array}{l}
    U_m = \left|U\right|
    
    \\
    \begin{array}{l}
    t_0 := \cos \left(\frac{K}{2}\right)\\
    t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{t\_0 \cdot \left(J \cdot 2\right)}\right)}^{2}}\\
    \mathbf{if}\;t\_1 \leq -\infty:\\
    \;\;\;\;-U\_m\\
    
    \mathbf{elif}\;t\_1 \leq 10^{+303}:\\
    \;\;\;\;\left(-2 \cdot \left(J \cdot \cos \left(K \cdot 0.5\right)\right)\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U\_m}{\mathsf{fma}\left(J, \cos K, J\right)}, \frac{U\_m}{J \cdot 2}, 1\right)}\\
    
    \mathbf{else}:\\
    \;\;\;\;\left(-U\_m\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m \cdot U\_m}, -1\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -inf.0

      1. Initial program 5.6%

        \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      2. 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.f6450.3

          \[\leadsto \color{blue}{-U} \]
      5. Applied rewrites50.3%

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

      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))))) < 1e303

      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. Step-by-step derivation
        1. lift-/.f64N/A

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \color{blue}{\left(\left(J \cdot \cos \left(K \cdot 0.5\right)\right) \cdot -2\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      5. Applied rewrites98.7%

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \left(\left(J \cdot \cos \left(K \cdot \frac{1}{2}\right)\right) \cdot -2\right) \cdot \sqrt{\frac{\color{blue}{\frac{U}{\mathsf{fma}\left(J, \cos K, J\right)} \cdot U}}{2 \cdot J} + 1} \]
        11. associate-/l*N/A

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

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

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

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

          \[\leadsto \left(\left(J \cdot \cos \left(K \cdot \frac{1}{2}\right)\right) \cdot -2\right) \cdot \sqrt{\frac{U}{\mathsf{fma}\left(J, \cos K, J\right)} \cdot \color{blue}{\frac{U}{J \cdot 2}} + 1} \]
        16. lower-fma.f6499.7

          \[\leadsto \left(\left(J \cdot \cos \left(K \cdot 0.5\right)\right) \cdot -2\right) \cdot \sqrt{\color{blue}{\mathsf{fma}\left(\frac{U}{\mathsf{fma}\left(J, \cos K, J\right)}, \frac{U}{J \cdot 2}, 1\right)}} \]
      7. Applied rewrites99.7%

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

      if 1e303 < (*.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 5.6%

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

        \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      4. Step-by-step derivation
        1. lower-*.f645.0

          \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      5. Applied rewrites5.0%

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

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

          \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
        2. lower-*.f645.0

          \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
      8. Applied rewrites5.0%

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

        \[\leadsto \color{blue}{-1 \cdot \left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
      10. Step-by-step derivation
        1. mul-1-negN/A

          \[\leadsto \color{blue}{\mathsf{neg}\left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
        2. distribute-rgt-neg-inN/A

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

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

          \[\leadsto U \cdot \color{blue}{\left(\mathsf{neg}\left(\left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)\right)} \]
        5. sub-negN/A

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

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

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

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

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

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

          \[\leadsto U \cdot \left(\mathsf{neg}\left(\mathsf{fma}\left(-2, \frac{J \cdot J}{\color{blue}{U \cdot U}}, -1\right)\right)\right) \]
        12. lower-*.f6453.6

          \[\leadsto U \cdot \left(-\mathsf{fma}\left(-2, \frac{J \cdot J}{\color{blue}{U \cdot U}}, -1\right)\right) \]
      11. Applied rewrites53.6%

        \[\leadsto \color{blue}{U \cdot \left(-\mathsf{fma}\left(-2, \frac{J \cdot J}{U \cdot U}, -1\right)\right)} \]
    3. Recombined 3 regimes into one program.
    4. Final simplification88.5%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq -\infty:\\ \;\;\;\;-U\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq 10^{+303}:\\ \;\;\;\;\left(-2 \cdot \left(J \cdot \cos \left(K \cdot 0.5\right)\right)\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U}{\mathsf{fma}\left(J, \cos K, J\right)}, \frac{U}{J \cdot 2}, 1\right)}\\ \mathbf{else}:\\ \;\;\;\;\left(-U\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U \cdot U}, -1\right)\\ \end{array} \]
    5. Add Preprocessing

    Alternative 8: 90.1% accurate, 0.4× speedup?

    \[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(-2 \cdot J\right) \cdot t\_0\\ t_2 := t\_1 \cdot \sqrt{1 + {\left(\frac{U\_m}{t\_0 \cdot \left(J \cdot 2\right)}\right)}^{2}}\\ \mathbf{if}\;t\_2 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_2 \leq 10^{+303}:\\ \;\;\;\;t\_1 \cdot \sqrt{1 + {\left(\frac{U\_m}{J \cdot 2}\right)}^{2}}\\ \mathbf{else}:\\ \;\;\;\;\left(-U\_m\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m \cdot U\_m}, -1\right)\\ \end{array} \end{array} \]
    U_m = (fabs.f64 U)
    (FPCore (J K U_m)
     :precision binary64
     (let* ((t_0 (cos (/ K 2.0)))
            (t_1 (* (* -2.0 J) t_0))
            (t_2 (* t_1 (sqrt (+ 1.0 (pow (/ U_m (* t_0 (* J 2.0))) 2.0))))))
       (if (<= t_2 (- INFINITY))
         (- U_m)
         (if (<= t_2 1e+303)
           (* t_1 (sqrt (+ 1.0 (pow (/ U_m (* J 2.0)) 2.0))))
           (* (- U_m) (fma -2.0 (/ (* J J) (* U_m U_m)) -1.0))))))
    U_m = fabs(U);
    double code(double J, double K, double U_m) {
    	double t_0 = cos((K / 2.0));
    	double t_1 = (-2.0 * J) * t_0;
    	double t_2 = t_1 * sqrt((1.0 + pow((U_m / (t_0 * (J * 2.0))), 2.0)));
    	double tmp;
    	if (t_2 <= -((double) INFINITY)) {
    		tmp = -U_m;
    	} else if (t_2 <= 1e+303) {
    		tmp = t_1 * sqrt((1.0 + pow((U_m / (J * 2.0)), 2.0)));
    	} else {
    		tmp = -U_m * fma(-2.0, ((J * J) / (U_m * U_m)), -1.0);
    	}
    	return tmp;
    }
    
    U_m = abs(U)
    function code(J, K, U_m)
    	t_0 = cos(Float64(K / 2.0))
    	t_1 = Float64(Float64(-2.0 * J) * t_0)
    	t_2 = Float64(t_1 * sqrt(Float64(1.0 + (Float64(U_m / Float64(t_0 * Float64(J * 2.0))) ^ 2.0))))
    	tmp = 0.0
    	if (t_2 <= Float64(-Inf))
    		tmp = Float64(-U_m);
    	elseif (t_2 <= 1e+303)
    		tmp = Float64(t_1 * sqrt(Float64(1.0 + (Float64(U_m / Float64(J * 2.0)) ^ 2.0))));
    	else
    		tmp = Float64(Float64(-U_m) * fma(-2.0, Float64(Float64(J * J) / Float64(U_m * U_m)), -1.0));
    	end
    	return tmp
    end
    
    U_m = N[Abs[U], $MachinePrecision]
    code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$1 * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(t$95$0 * N[(J * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$2, (-Infinity)], (-U$95$m), If[LessEqual[t$95$2, 1e+303], N[(t$95$1 * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(J * 2.0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[((-U$95$m) * N[(-2.0 * N[(N[(J * J), $MachinePrecision] / N[(U$95$m * U$95$m), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]]]]]]
    
    \begin{array}{l}
    U_m = \left|U\right|
    
    \\
    \begin{array}{l}
    t_0 := \cos \left(\frac{K}{2}\right)\\
    t_1 := \left(-2 \cdot J\right) \cdot t\_0\\
    t_2 := t\_1 \cdot \sqrt{1 + {\left(\frac{U\_m}{t\_0 \cdot \left(J \cdot 2\right)}\right)}^{2}}\\
    \mathbf{if}\;t\_2 \leq -\infty:\\
    \;\;\;\;-U\_m\\
    
    \mathbf{elif}\;t\_2 \leq 10^{+303}:\\
    \;\;\;\;t\_1 \cdot \sqrt{1 + {\left(\frac{U\_m}{J \cdot 2}\right)}^{2}}\\
    
    \mathbf{else}:\\
    \;\;\;\;\left(-U\_m\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m \cdot U\_m}, -1\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -inf.0

      1. Initial program 5.6%

        \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      2. 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.f6450.3

          \[\leadsto \color{blue}{-U} \]
      5. Applied rewrites50.3%

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

      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))))) < 1e303

      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

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \color{blue}{1}}\right)}^{2}} \]
      4. Step-by-step derivation
        1. Applied rewrites86.5%

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

        if 1e303 < (*.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 5.6%

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

          \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        4. Step-by-step derivation
          1. lower-*.f645.0

            \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        5. Applied rewrites5.0%

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

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

            \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
          2. lower-*.f645.0

            \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
        8. Applied rewrites5.0%

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

          \[\leadsto \color{blue}{-1 \cdot \left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
        10. Step-by-step derivation
          1. mul-1-negN/A

            \[\leadsto \color{blue}{\mathsf{neg}\left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
          2. distribute-rgt-neg-inN/A

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

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

            \[\leadsto U \cdot \color{blue}{\left(\mathsf{neg}\left(\left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)\right)} \]
          5. sub-negN/A

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

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

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

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

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

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

            \[\leadsto U \cdot \left(\mathsf{neg}\left(\mathsf{fma}\left(-2, \frac{J \cdot J}{\color{blue}{U \cdot U}}, -1\right)\right)\right) \]
          12. lower-*.f6453.6

            \[\leadsto U \cdot \left(-\mathsf{fma}\left(-2, \frac{J \cdot J}{\color{blue}{U \cdot U}}, -1\right)\right) \]
        11. Applied rewrites53.6%

          \[\leadsto \color{blue}{U \cdot \left(-\mathsf{fma}\left(-2, \frac{J \cdot J}{U \cdot U}, -1\right)\right)} \]
      5. Recombined 3 regimes into one program.
      6. Final simplification78.4%

        \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq -\infty:\\ \;\;\;\;-U\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq 10^{+303}:\\ \;\;\;\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{J \cdot 2}\right)}^{2}}\\ \mathbf{else}:\\ \;\;\;\;\left(-U\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U \cdot U}, -1\right)\\ \end{array} \]
      7. Add Preprocessing

      Alternative 9: 88.3% accurate, 0.4× speedup?

      \[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{t\_0 \cdot \left(J \cdot 2\right)}\right)}^{2}}\\ \mathbf{if}\;t\_1 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_1 \leq 10^{+303}:\\ \;\;\;\;\left(-2 \cdot \left(J \cdot \cos \left(K \cdot 0.5\right)\right)\right) \cdot \sqrt{1 + \frac{U\_m \cdot \frac{U\_m}{J \cdot 2}}{J \cdot 2}}\\ \mathbf{else}:\\ \;\;\;\;\left(-U\_m\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m \cdot U\_m}, -1\right)\\ \end{array} \end{array} \]
      U_m = (fabs.f64 U)
      (FPCore (J K U_m)
       :precision binary64
       (let* ((t_0 (cos (/ K 2.0)))
              (t_1
               (*
                (* (* -2.0 J) t_0)
                (sqrt (+ 1.0 (pow (/ U_m (* t_0 (* J 2.0))) 2.0))))))
         (if (<= t_1 (- INFINITY))
           (- U_m)
           (if (<= t_1 1e+303)
             (*
              (* -2.0 (* J (cos (* K 0.5))))
              (sqrt (+ 1.0 (/ (* U_m (/ U_m (* J 2.0))) (* J 2.0)))))
             (* (- U_m) (fma -2.0 (/ (* J J) (* U_m U_m)) -1.0))))))
      U_m = fabs(U);
      double code(double J, double K, double U_m) {
      	double t_0 = cos((K / 2.0));
      	double t_1 = ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U_m / (t_0 * (J * 2.0))), 2.0)));
      	double tmp;
      	if (t_1 <= -((double) INFINITY)) {
      		tmp = -U_m;
      	} else if (t_1 <= 1e+303) {
      		tmp = (-2.0 * (J * cos((K * 0.5)))) * sqrt((1.0 + ((U_m * (U_m / (J * 2.0))) / (J * 2.0))));
      	} else {
      		tmp = -U_m * fma(-2.0, ((J * J) / (U_m * U_m)), -1.0);
      	}
      	return tmp;
      }
      
      U_m = abs(U)
      function code(J, K, U_m)
      	t_0 = cos(Float64(K / 2.0))
      	t_1 = Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(t_0 * Float64(J * 2.0))) ^ 2.0))))
      	tmp = 0.0
      	if (t_1 <= Float64(-Inf))
      		tmp = Float64(-U_m);
      	elseif (t_1 <= 1e+303)
      		tmp = Float64(Float64(-2.0 * Float64(J * cos(Float64(K * 0.5)))) * sqrt(Float64(1.0 + Float64(Float64(U_m * Float64(U_m / Float64(J * 2.0))) / Float64(J * 2.0)))));
      	else
      		tmp = Float64(Float64(-U_m) * fma(-2.0, Float64(Float64(J * J) / Float64(U_m * U_m)), -1.0));
      	end
      	return tmp
      end
      
      U_m = N[Abs[U], $MachinePrecision]
      code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(t$95$0 * N[(J * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, (-Infinity)], (-U$95$m), If[LessEqual[t$95$1, 1e+303], N[(N[(-2.0 * N[(J * N[Cos[N[(K * 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Sqrt[N[(1.0 + N[(N[(U$95$m * N[(U$95$m / N[(J * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(J * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[((-U$95$m) * N[(-2.0 * N[(N[(J * J), $MachinePrecision] / N[(U$95$m * U$95$m), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]]]]]
      
      \begin{array}{l}
      U_m = \left|U\right|
      
      \\
      \begin{array}{l}
      t_0 := \cos \left(\frac{K}{2}\right)\\
      t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{t\_0 \cdot \left(J \cdot 2\right)}\right)}^{2}}\\
      \mathbf{if}\;t\_1 \leq -\infty:\\
      \;\;\;\;-U\_m\\
      
      \mathbf{elif}\;t\_1 \leq 10^{+303}:\\
      \;\;\;\;\left(-2 \cdot \left(J \cdot \cos \left(K \cdot 0.5\right)\right)\right) \cdot \sqrt{1 + \frac{U\_m \cdot \frac{U\_m}{J \cdot 2}}{J \cdot 2}}\\
      
      \mathbf{else}:\\
      \;\;\;\;\left(-U\_m\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m \cdot U\_m}, -1\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 3 regimes
      2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -inf.0

        1. Initial program 5.6%

          \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        2. 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.f6450.3

            \[\leadsto \color{blue}{-U} \]
        5. Applied rewrites50.3%

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

        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))))) < 1e303

        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. Step-by-step derivation
          1. lift-/.f64N/A

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \color{blue}{\left(\left(J \cdot \cos \left(K \cdot 0.5\right)\right) \cdot -2\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        5. Applied rewrites98.7%

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

          \[\leadsto \left(\left(J \cdot \cos \left(K \cdot \frac{1}{2}\right)\right) \cdot -2\right) \cdot \sqrt{1 + \frac{U \cdot \frac{U}{\color{blue}{2 \cdot J}}}{2 \cdot J}} \]
        7. Step-by-step derivation
          1. lower-*.f6486.0

            \[\leadsto \left(\left(J \cdot \cos \left(K \cdot 0.5\right)\right) \cdot -2\right) \cdot \sqrt{1 + \frac{U \cdot \frac{U}{\color{blue}{2 \cdot J}}}{2 \cdot J}} \]
        8. Applied rewrites86.0%

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

        if 1e303 < (*.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 5.6%

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

          \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        4. Step-by-step derivation
          1. lower-*.f645.0

            \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        5. Applied rewrites5.0%

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

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

            \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
          2. lower-*.f645.0

            \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
        8. Applied rewrites5.0%

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

          \[\leadsto \color{blue}{-1 \cdot \left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
        10. Step-by-step derivation
          1. mul-1-negN/A

            \[\leadsto \color{blue}{\mathsf{neg}\left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
          2. distribute-rgt-neg-inN/A

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

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

            \[\leadsto U \cdot \color{blue}{\left(\mathsf{neg}\left(\left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)\right)} \]
          5. sub-negN/A

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

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

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

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

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

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

            \[\leadsto U \cdot \left(\mathsf{neg}\left(\mathsf{fma}\left(-2, \frac{J \cdot J}{\color{blue}{U \cdot U}}, -1\right)\right)\right) \]
          12. lower-*.f6453.6

            \[\leadsto U \cdot \left(-\mathsf{fma}\left(-2, \frac{J \cdot J}{\color{blue}{U \cdot U}}, -1\right)\right) \]
        11. Applied rewrites53.6%

          \[\leadsto \color{blue}{U \cdot \left(-\mathsf{fma}\left(-2, \frac{J \cdot J}{U \cdot U}, -1\right)\right)} \]
      3. Recombined 3 regimes into one program.
      4. Final simplification78.0%

        \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq -\infty:\\ \;\;\;\;-U\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq 10^{+303}:\\ \;\;\;\;\left(-2 \cdot \left(J \cdot \cos \left(K \cdot 0.5\right)\right)\right) \cdot \sqrt{1 + \frac{U \cdot \frac{U}{J \cdot 2}}{J \cdot 2}}\\ \mathbf{else}:\\ \;\;\;\;\left(-U\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U \cdot U}, -1\right)\\ \end{array} \]
      5. Add Preprocessing

      Alternative 10: 61.0% accurate, 0.5× speedup?

      \[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{t\_0 \cdot \left(J \cdot 2\right)}\right)}^{2}}\\ \mathbf{if}\;t\_1 \leq -\infty:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_1 \leq 10^{-150}:\\ \;\;\;\;J \cdot \left(-2 \cdot \sqrt{\mathsf{fma}\left(\frac{U\_m}{J} \cdot \frac{U\_m}{J}, 0.25, 1\right)}\right)\\ \mathbf{else}:\\ \;\;\;\;\left(-U\_m\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m \cdot U\_m}, -1\right)\\ \end{array} \end{array} \]
      U_m = (fabs.f64 U)
      (FPCore (J K U_m)
       :precision binary64
       (let* ((t_0 (cos (/ K 2.0)))
              (t_1
               (*
                (* (* -2.0 J) t_0)
                (sqrt (+ 1.0 (pow (/ U_m (* t_0 (* J 2.0))) 2.0))))))
         (if (<= t_1 (- INFINITY))
           (- U_m)
           (if (<= t_1 1e-150)
             (* J (* -2.0 (sqrt (fma (* (/ U_m J) (/ U_m J)) 0.25 1.0))))
             (* (- U_m) (fma -2.0 (/ (* J J) (* U_m U_m)) -1.0))))))
      U_m = fabs(U);
      double code(double J, double K, double U_m) {
      	double t_0 = cos((K / 2.0));
      	double t_1 = ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U_m / (t_0 * (J * 2.0))), 2.0)));
      	double tmp;
      	if (t_1 <= -((double) INFINITY)) {
      		tmp = -U_m;
      	} else if (t_1 <= 1e-150) {
      		tmp = J * (-2.0 * sqrt(fma(((U_m / J) * (U_m / J)), 0.25, 1.0)));
      	} else {
      		tmp = -U_m * fma(-2.0, ((J * J) / (U_m * U_m)), -1.0);
      	}
      	return tmp;
      }
      
      U_m = abs(U)
      function code(J, K, U_m)
      	t_0 = cos(Float64(K / 2.0))
      	t_1 = Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(t_0 * Float64(J * 2.0))) ^ 2.0))))
      	tmp = 0.0
      	if (t_1 <= Float64(-Inf))
      		tmp = Float64(-U_m);
      	elseif (t_1 <= 1e-150)
      		tmp = Float64(J * Float64(-2.0 * sqrt(fma(Float64(Float64(U_m / J) * Float64(U_m / J)), 0.25, 1.0))));
      	else
      		tmp = Float64(Float64(-U_m) * fma(-2.0, Float64(Float64(J * J) / Float64(U_m * U_m)), -1.0));
      	end
      	return tmp
      end
      
      U_m = N[Abs[U], $MachinePrecision]
      code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(t$95$0 * N[(J * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, (-Infinity)], (-U$95$m), If[LessEqual[t$95$1, 1e-150], N[(J * N[(-2.0 * N[Sqrt[N[(N[(N[(U$95$m / J), $MachinePrecision] * N[(U$95$m / J), $MachinePrecision]), $MachinePrecision] * 0.25 + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[((-U$95$m) * N[(-2.0 * N[(N[(J * J), $MachinePrecision] / N[(U$95$m * U$95$m), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]]]]]
      
      \begin{array}{l}
      U_m = \left|U\right|
      
      \\
      \begin{array}{l}
      t_0 := \cos \left(\frac{K}{2}\right)\\
      t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{t\_0 \cdot \left(J \cdot 2\right)}\right)}^{2}}\\
      \mathbf{if}\;t\_1 \leq -\infty:\\
      \;\;\;\;-U\_m\\
      
      \mathbf{elif}\;t\_1 \leq 10^{-150}:\\
      \;\;\;\;J \cdot \left(-2 \cdot \sqrt{\mathsf{fma}\left(\frac{U\_m}{J} \cdot \frac{U\_m}{J}, 0.25, 1\right)}\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\left(-U\_m\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m \cdot U\_m}, -1\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 3 regimes
      2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -inf.0

        1. Initial program 5.6%

          \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        2. 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.f6450.3

            \[\leadsto \color{blue}{-U} \]
        5. Applied rewrites50.3%

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

        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))))) < 1.00000000000000001e-150

        1. Initial program 99.7%

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

          \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        4. Step-by-step derivation
          1. lower-*.f6451.4

            \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        5. Applied rewrites51.4%

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

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

            \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
          2. lower-*.f6457.1

            \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
        8. Applied rewrites57.1%

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \color{blue}{\left(\sqrt{1 + {\left(\frac{U}{J \cdot 2}\right)}^{2}} \cdot -2\right) \cdot J} \]
        10. Applied rewrites57.1%

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

        if 1.00000000000000001e-150 < (*.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 76.8%

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

          \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        4. Step-by-step derivation
          1. lower-*.f6444.8

            \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        5. Applied rewrites44.8%

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

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

            \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
          2. lower-*.f6447.9

            \[\leadsto \left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{J \cdot 2}}\right)}^{2}} \]
        8. Applied rewrites47.9%

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

          \[\leadsto \color{blue}{-1 \cdot \left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
        10. Step-by-step derivation
          1. mul-1-negN/A

            \[\leadsto \color{blue}{\mathsf{neg}\left(U \cdot \left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)} \]
          2. distribute-rgt-neg-inN/A

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

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

            \[\leadsto U \cdot \color{blue}{\left(\mathsf{neg}\left(\left(-2 \cdot \frac{{J}^{2}}{{U}^{2}} - 1\right)\right)\right)} \]
          5. sub-negN/A

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

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

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

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

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

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

            \[\leadsto U \cdot \left(\mathsf{neg}\left(\mathsf{fma}\left(-2, \frac{J \cdot J}{\color{blue}{U \cdot U}}, -1\right)\right)\right) \]
          12. lower-*.f6425.9

            \[\leadsto U \cdot \left(-\mathsf{fma}\left(-2, \frac{J \cdot J}{\color{blue}{U \cdot U}}, -1\right)\right) \]
        11. Applied rewrites25.9%

          \[\leadsto \color{blue}{U \cdot \left(-\mathsf{fma}\left(-2, \frac{J \cdot J}{U \cdot U}, -1\right)\right)} \]
      3. Recombined 3 regimes into one program.
      4. Final simplification41.3%

        \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq -\infty:\\ \;\;\;\;-U\\ \mathbf{elif}\;\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \leq 10^{-150}:\\ \;\;\;\;J \cdot \left(-2 \cdot \sqrt{\mathsf{fma}\left(\frac{U}{J} \cdot \frac{U}{J}, 0.25, 1\right)}\right)\\ \mathbf{else}:\\ \;\;\;\;\left(-U\right) \cdot \mathsf{fma}\left(-2, \frac{J \cdot J}{U \cdot U}, -1\right)\\ \end{array} \]
      5. Add Preprocessing

      Alternative 11: 32.0% accurate, 12.0× speedup?

      \[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} \mathbf{if}\;J \leq 1060000000:\\ \;\;\;\;\mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m}, -U\_m\right)\\ \mathbf{else}:\\ \;\;\;\;-2 \cdot J\\ \end{array} \end{array} \]
      U_m = (fabs.f64 U)
      (FPCore (J K U_m)
       :precision binary64
       (if (<= J 1060000000.0) (fma -2.0 (/ (* J J) U_m) (- U_m)) (* -2.0 J)))
      U_m = fabs(U);
      double code(double J, double K, double U_m) {
      	double tmp;
      	if (J <= 1060000000.0) {
      		tmp = fma(-2.0, ((J * J) / U_m), -U_m);
      	} else {
      		tmp = -2.0 * J;
      	}
      	return tmp;
      }
      
      U_m = abs(U)
      function code(J, K, U_m)
      	tmp = 0.0
      	if (J <= 1060000000.0)
      		tmp = fma(-2.0, Float64(Float64(J * J) / U_m), Float64(-U_m));
      	else
      		tmp = Float64(-2.0 * J);
      	end
      	return tmp
      end
      
      U_m = N[Abs[U], $MachinePrecision]
      code[J_, K_, U$95$m_] := If[LessEqual[J, 1060000000.0], N[(-2.0 * N[(N[(J * J), $MachinePrecision] / U$95$m), $MachinePrecision] + (-U$95$m)), $MachinePrecision], N[(-2.0 * J), $MachinePrecision]]
      
      \begin{array}{l}
      U_m = \left|U\right|
      
      \\
      \begin{array}{l}
      \mathbf{if}\;J \leq 1060000000:\\
      \;\;\;\;\mathsf{fma}\left(-2, \frac{J \cdot J}{U\_m}, -U\_m\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;-2 \cdot J\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if J < 1.06e9

        1. Initial program 72.1%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \mathsf{fma}\left(\frac{{\cos \left(\frac{1}{2} \cdot K\right)}^{2}}{U}, -2 \cdot \left(J \cdot J\right), \color{blue}{\mathsf{neg}\left(U\right)}\right) \]
          15. lower-neg.f6424.8

            \[\leadsto \mathsf{fma}\left(\frac{{\cos \left(0.5 \cdot K\right)}^{2}}{U}, -2 \cdot \left(J \cdot J\right), \color{blue}{-U}\right) \]
        5. Applied rewrites24.8%

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

          \[\leadsto \color{blue}{-2 \cdot \frac{{J}^{2}}{U} - U} \]
        7. Step-by-step derivation
          1. sub-negN/A

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

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

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

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

            \[\leadsto \mathsf{fma}\left(-2, \frac{\color{blue}{J \cdot J}}{U}, \mathsf{neg}\left(U\right)\right) \]
          6. lower-neg.f6424.8

            \[\leadsto \mathsf{fma}\left(-2, \frac{J \cdot J}{U}, \color{blue}{-U}\right) \]
        8. Applied rewrites24.8%

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

        if 1.06e9 < J

        1. Initial program 98.0%

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

          \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        4. Step-by-step derivation
          1. lower-*.f6450.9

            \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        5. Applied rewrites50.9%

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

          \[\leadsto \color{blue}{-2 \cdot J} \]
        7. Step-by-step derivation
          1. lower-*.f6440.4

            \[\leadsto \color{blue}{-2 \cdot J} \]
        8. Applied rewrites40.4%

          \[\leadsto \color{blue}{-2 \cdot J} \]
      3. Recombined 2 regimes into one program.
      4. Add Preprocessing

      Alternative 12: 32.4% accurate, 31.0× speedup?

      \[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} \mathbf{if}\;J \leq 1060000000:\\ \;\;\;\;-U\_m\\ \mathbf{else}:\\ \;\;\;\;-2 \cdot J\\ \end{array} \end{array} \]
      U_m = (fabs.f64 U)
      (FPCore (J K U_m)
       :precision binary64
       (if (<= J 1060000000.0) (- U_m) (* -2.0 J)))
      U_m = fabs(U);
      double code(double J, double K, double U_m) {
      	double tmp;
      	if (J <= 1060000000.0) {
      		tmp = -U_m;
      	} else {
      		tmp = -2.0 * J;
      	}
      	return tmp;
      }
      
      U_m = abs(u)
      real(8) function code(j, k, u_m)
          real(8), intent (in) :: j
          real(8), intent (in) :: k
          real(8), intent (in) :: u_m
          real(8) :: tmp
          if (j <= 1060000000.0d0) then
              tmp = -u_m
          else
              tmp = (-2.0d0) * j
          end if
          code = tmp
      end function
      
      U_m = Math.abs(U);
      public static double code(double J, double K, double U_m) {
      	double tmp;
      	if (J <= 1060000000.0) {
      		tmp = -U_m;
      	} else {
      		tmp = -2.0 * J;
      	}
      	return tmp;
      }
      
      U_m = math.fabs(U)
      def code(J, K, U_m):
      	tmp = 0
      	if J <= 1060000000.0:
      		tmp = -U_m
      	else:
      		tmp = -2.0 * J
      	return tmp
      
      U_m = abs(U)
      function code(J, K, U_m)
      	tmp = 0.0
      	if (J <= 1060000000.0)
      		tmp = Float64(-U_m);
      	else
      		tmp = Float64(-2.0 * J);
      	end
      	return tmp
      end
      
      U_m = abs(U);
      function tmp_2 = code(J, K, U_m)
      	tmp = 0.0;
      	if (J <= 1060000000.0)
      		tmp = -U_m;
      	else
      		tmp = -2.0 * J;
      	end
      	tmp_2 = tmp;
      end
      
      U_m = N[Abs[U], $MachinePrecision]
      code[J_, K_, U$95$m_] := If[LessEqual[J, 1060000000.0], (-U$95$m), N[(-2.0 * J), $MachinePrecision]]
      
      \begin{array}{l}
      U_m = \left|U\right|
      
      \\
      \begin{array}{l}
      \mathbf{if}\;J \leq 1060000000:\\
      \;\;\;\;-U\_m\\
      
      \mathbf{else}:\\
      \;\;\;\;-2 \cdot J\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if J < 1.06e9

        1. Initial program 72.1%

          \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        2. Add Preprocessing
        3. Taylor expanded in 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.f6425.1

            \[\leadsto \color{blue}{-U} \]
        5. Applied rewrites25.1%

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

        if 1.06e9 < J

        1. Initial program 98.0%

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

          \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        4. Step-by-step derivation
          1. lower-*.f6450.9

            \[\leadsto \color{blue}{\left(-2 \cdot J\right)} \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        5. Applied rewrites50.9%

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

          \[\leadsto \color{blue}{-2 \cdot J} \]
        7. Step-by-step derivation
          1. lower-*.f6440.4

            \[\leadsto \color{blue}{-2 \cdot J} \]
        8. Applied rewrites40.4%

          \[\leadsto \color{blue}{-2 \cdot J} \]
      3. Recombined 2 regimes into one program.
      4. Add Preprocessing

      Alternative 13: 26.4% accurate, 124.3× speedup?

      \[\begin{array}{l} U_m = \left|U\right| \\ -U\_m \end{array} \]
      U_m = (fabs.f64 U)
      (FPCore (J K U_m) :precision binary64 (- U_m))
      U_m = fabs(U);
      double code(double J, double K, double U_m) {
      	return -U_m;
      }
      
      U_m = abs(u)
      real(8) function code(j, k, u_m)
          real(8), intent (in) :: j
          real(8), intent (in) :: k
          real(8), intent (in) :: u_m
          code = -u_m
      end function
      
      U_m = Math.abs(U);
      public static double code(double J, double K, double U_m) {
      	return -U_m;
      }
      
      U_m = math.fabs(U)
      def code(J, K, U_m):
      	return -U_m
      
      U_m = abs(U)
      function code(J, K, U_m)
      	return Float64(-U_m)
      end
      
      U_m = abs(U);
      function tmp = code(J, K, U_m)
      	tmp = -U_m;
      end
      
      U_m = N[Abs[U], $MachinePrecision]
      code[J_, K_, U$95$m_] := (-U$95$m)
      
      \begin{array}{l}
      U_m = \left|U\right|
      
      \\
      -U\_m
      \end{array}
      
      Derivation
      1. Initial program 77.7%

        \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      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.f6422.9

          \[\leadsto \color{blue}{-U} \]
      5. Applied rewrites22.9%

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

      Reproduce

      ?
      herbie shell --seed 2024216 
      (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)))))