Toniolo and Linder, Equation (3a)

Percentage Accurate: 98.4% → 99.3%
Time: 7.8s
Alternatives: 5
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \end{array} \]
(FPCore (l Om kx ky)
 :precision binary64
 (sqrt
  (*
   (/ 1.0 2.0)
   (+
    1.0
    (/
     1.0
     (sqrt
      (+
       1.0
       (*
        (pow (/ (* 2.0 l) Om) 2.0)
        (+ (pow (sin kx) 2.0) (pow (sin ky) 2.0))))))))))
double code(double l, double Om, double kx, double ky) {
	return sqrt(((1.0 / 2.0) * (1.0 + (1.0 / sqrt((1.0 + (pow(((2.0 * l) / Om), 2.0) * (pow(sin(kx), 2.0) + pow(sin(ky), 2.0)))))))));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

real(8) function code(l, om, kx, ky)
use fmin_fmax_functions
    real(8), intent (in) :: l
    real(8), intent (in) :: om
    real(8), intent (in) :: kx
    real(8), intent (in) :: ky
    code = sqrt(((1.0d0 / 2.0d0) * (1.0d0 + (1.0d0 / sqrt((1.0d0 + ((((2.0d0 * l) / om) ** 2.0d0) * ((sin(kx) ** 2.0d0) + (sin(ky) ** 2.0d0)))))))))
end function
public static double code(double l, double Om, double kx, double ky) {
	return Math.sqrt(((1.0 / 2.0) * (1.0 + (1.0 / Math.sqrt((1.0 + (Math.pow(((2.0 * l) / Om), 2.0) * (Math.pow(Math.sin(kx), 2.0) + Math.pow(Math.sin(ky), 2.0)))))))));
}
def code(l, Om, kx, ky):
	return math.sqrt(((1.0 / 2.0) * (1.0 + (1.0 / math.sqrt((1.0 + (math.pow(((2.0 * l) / Om), 2.0) * (math.pow(math.sin(kx), 2.0) + math.pow(math.sin(ky), 2.0)))))))))
function code(l, Om, kx, ky)
	return sqrt(Float64(Float64(1.0 / 2.0) * Float64(1.0 + Float64(1.0 / sqrt(Float64(1.0 + Float64((Float64(Float64(2.0 * l) / Om) ^ 2.0) * Float64((sin(kx) ^ 2.0) + (sin(ky) ^ 2.0)))))))))
end
function tmp = code(l, Om, kx, ky)
	tmp = sqrt(((1.0 / 2.0) * (1.0 + (1.0 / sqrt((1.0 + ((((2.0 * l) / Om) ^ 2.0) * ((sin(kx) ^ 2.0) + (sin(ky) ^ 2.0)))))))));
end
code[l_, Om_, kx_, ky_] := N[Sqrt[N[(N[(1.0 / 2.0), $MachinePrecision] * N[(1.0 + N[(1.0 / N[Sqrt[N[(1.0 + N[(N[Power[N[(N[(2.0 * l), $MachinePrecision] / Om), $MachinePrecision], 2.0], $MachinePrecision] * N[(N[Power[N[Sin[kx], $MachinePrecision], 2.0], $MachinePrecision] + N[Power[N[Sin[ky], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)}
\end{array}

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 5 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: 98.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \end{array} \]
(FPCore (l Om kx ky)
 :precision binary64
 (sqrt
  (*
   (/ 1.0 2.0)
   (+
    1.0
    (/
     1.0
     (sqrt
      (+
       1.0
       (*
        (pow (/ (* 2.0 l) Om) 2.0)
        (+ (pow (sin kx) 2.0) (pow (sin ky) 2.0))))))))))
double code(double l, double Om, double kx, double ky) {
	return sqrt(((1.0 / 2.0) * (1.0 + (1.0 / sqrt((1.0 + (pow(((2.0 * l) / Om), 2.0) * (pow(sin(kx), 2.0) + pow(sin(ky), 2.0)))))))));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

real(8) function code(l, om, kx, ky)
use fmin_fmax_functions
    real(8), intent (in) :: l
    real(8), intent (in) :: om
    real(8), intent (in) :: kx
    real(8), intent (in) :: ky
    code = sqrt(((1.0d0 / 2.0d0) * (1.0d0 + (1.0d0 / sqrt((1.0d0 + ((((2.0d0 * l) / om) ** 2.0d0) * ((sin(kx) ** 2.0d0) + (sin(ky) ** 2.0d0)))))))))
end function
public static double code(double l, double Om, double kx, double ky) {
	return Math.sqrt(((1.0 / 2.0) * (1.0 + (1.0 / Math.sqrt((1.0 + (Math.pow(((2.0 * l) / Om), 2.0) * (Math.pow(Math.sin(kx), 2.0) + Math.pow(Math.sin(ky), 2.0)))))))));
}
def code(l, Om, kx, ky):
	return math.sqrt(((1.0 / 2.0) * (1.0 + (1.0 / math.sqrt((1.0 + (math.pow(((2.0 * l) / Om), 2.0) * (math.pow(math.sin(kx), 2.0) + math.pow(math.sin(ky), 2.0)))))))))
function code(l, Om, kx, ky)
	return sqrt(Float64(Float64(1.0 / 2.0) * Float64(1.0 + Float64(1.0 / sqrt(Float64(1.0 + Float64((Float64(Float64(2.0 * l) / Om) ^ 2.0) * Float64((sin(kx) ^ 2.0) + (sin(ky) ^ 2.0)))))))))
end
function tmp = code(l, Om, kx, ky)
	tmp = sqrt(((1.0 / 2.0) * (1.0 + (1.0 / sqrt((1.0 + ((((2.0 * l) / Om) ^ 2.0) * ((sin(kx) ^ 2.0) + (sin(ky) ^ 2.0)))))))));
end
code[l_, Om_, kx_, ky_] := N[Sqrt[N[(N[(1.0 / 2.0), $MachinePrecision] * N[(1.0 + N[(1.0 / N[Sqrt[N[(1.0 + N[(N[Power[N[(N[(2.0 * l), $MachinePrecision] / Om), $MachinePrecision], 2.0], $MachinePrecision] * N[(N[Power[N[Sin[kx], $MachinePrecision], 2.0], $MachinePrecision] + N[Power[N[Sin[ky], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)}
\end{array}

Alternative 1: 99.3% accurate, 1.0× speedup?

\[\begin{array}{l} kx_m = \left|kx\right| \\ ky_m = \left|ky\right| \\ [l, Om, kx_m, ky_m] = \mathsf{sort}([l, Om, kx_m, ky_m])\\ \\ \begin{array}{l} \mathbf{if}\;ky\_m \leq 9.8 \cdot 10^{-191}:\\ \;\;\;\;\sqrt{0.5 + \frac{0.5}{\sqrt{1 + 4 \cdot \frac{{\left(\ell \cdot \sin ky\_m\right)}^{2}}{Om \cdot Om}}}}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx\_m}^{2} + {\sin ky\_m}^{2}\right)}}\right)}\\ \end{array} \end{array} \]
kx_m = (fabs.f64 kx)
ky_m = (fabs.f64 ky)
NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
(FPCore (l Om kx_m ky_m)
 :precision binary64
 (if (<= ky_m 9.8e-191)
   (sqrt
    (+
     0.5
     (/ 0.5 (sqrt (+ 1.0 (* 4.0 (/ (pow (* l (sin ky_m)) 2.0) (* Om Om))))))))
   (sqrt
    (*
     (/ 1.0 2.0)
     (+
      1.0
      (/
       1.0
       (sqrt
        (+
         1.0
         (*
          (pow (/ (* 2.0 l) Om) 2.0)
          (+ (pow (sin kx_m) 2.0) (pow (sin ky_m) 2.0)))))))))))
kx_m = fabs(kx);
ky_m = fabs(ky);
assert(l < Om && Om < kx_m && kx_m < ky_m);
double code(double l, double Om, double kx_m, double ky_m) {
	double tmp;
	if (ky_m <= 9.8e-191) {
		tmp = sqrt((0.5 + (0.5 / sqrt((1.0 + (4.0 * (pow((l * sin(ky_m)), 2.0) / (Om * Om))))))));
	} else {
		tmp = sqrt(((1.0 / 2.0) * (1.0 + (1.0 / sqrt((1.0 + (pow(((2.0 * l) / Om), 2.0) * (pow(sin(kx_m), 2.0) + pow(sin(ky_m), 2.0)))))))));
	}
	return tmp;
}
kx_m =     private
ky_m =     private
NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

real(8) function code(l, om, kx_m, ky_m)
use fmin_fmax_functions
    real(8), intent (in) :: l
    real(8), intent (in) :: om
    real(8), intent (in) :: kx_m
    real(8), intent (in) :: ky_m
    real(8) :: tmp
    if (ky_m <= 9.8d-191) then
        tmp = sqrt((0.5d0 + (0.5d0 / sqrt((1.0d0 + (4.0d0 * (((l * sin(ky_m)) ** 2.0d0) / (om * om))))))))
    else
        tmp = sqrt(((1.0d0 / 2.0d0) * (1.0d0 + (1.0d0 / sqrt((1.0d0 + ((((2.0d0 * l) / om) ** 2.0d0) * ((sin(kx_m) ** 2.0d0) + (sin(ky_m) ** 2.0d0)))))))))
    end if
    code = tmp
end function
kx_m = Math.abs(kx);
ky_m = Math.abs(ky);
assert l < Om && Om < kx_m && kx_m < ky_m;
public static double code(double l, double Om, double kx_m, double ky_m) {
	double tmp;
	if (ky_m <= 9.8e-191) {
		tmp = Math.sqrt((0.5 + (0.5 / Math.sqrt((1.0 + (4.0 * (Math.pow((l * Math.sin(ky_m)), 2.0) / (Om * Om))))))));
	} else {
		tmp = Math.sqrt(((1.0 / 2.0) * (1.0 + (1.0 / Math.sqrt((1.0 + (Math.pow(((2.0 * l) / Om), 2.0) * (Math.pow(Math.sin(kx_m), 2.0) + Math.pow(Math.sin(ky_m), 2.0)))))))));
	}
	return tmp;
}
kx_m = math.fabs(kx)
ky_m = math.fabs(ky)
[l, Om, kx_m, ky_m] = sort([l, Om, kx_m, ky_m])
def code(l, Om, kx_m, ky_m):
	tmp = 0
	if ky_m <= 9.8e-191:
		tmp = math.sqrt((0.5 + (0.5 / math.sqrt((1.0 + (4.0 * (math.pow((l * math.sin(ky_m)), 2.0) / (Om * Om))))))))
	else:
		tmp = math.sqrt(((1.0 / 2.0) * (1.0 + (1.0 / math.sqrt((1.0 + (math.pow(((2.0 * l) / Om), 2.0) * (math.pow(math.sin(kx_m), 2.0) + math.pow(math.sin(ky_m), 2.0)))))))))
	return tmp
kx_m = abs(kx)
ky_m = abs(ky)
l, Om, kx_m, ky_m = sort([l, Om, kx_m, ky_m])
function code(l, Om, kx_m, ky_m)
	tmp = 0.0
	if (ky_m <= 9.8e-191)
		tmp = sqrt(Float64(0.5 + Float64(0.5 / sqrt(Float64(1.0 + Float64(4.0 * Float64((Float64(l * sin(ky_m)) ^ 2.0) / Float64(Om * Om))))))));
	else
		tmp = sqrt(Float64(Float64(1.0 / 2.0) * Float64(1.0 + Float64(1.0 / sqrt(Float64(1.0 + Float64((Float64(Float64(2.0 * l) / Om) ^ 2.0) * Float64((sin(kx_m) ^ 2.0) + (sin(ky_m) ^ 2.0)))))))));
	end
	return tmp
end
kx_m = abs(kx);
ky_m = abs(ky);
l, Om, kx_m, ky_m = num2cell(sort([l, Om, kx_m, ky_m])){:}
function tmp_2 = code(l, Om, kx_m, ky_m)
	tmp = 0.0;
	if (ky_m <= 9.8e-191)
		tmp = sqrt((0.5 + (0.5 / sqrt((1.0 + (4.0 * (((l * sin(ky_m)) ^ 2.0) / (Om * Om))))))));
	else
		tmp = sqrt(((1.0 / 2.0) * (1.0 + (1.0 / sqrt((1.0 + ((((2.0 * l) / Om) ^ 2.0) * ((sin(kx_m) ^ 2.0) + (sin(ky_m) ^ 2.0)))))))));
	end
	tmp_2 = tmp;
end
kx_m = N[Abs[kx], $MachinePrecision]
ky_m = N[Abs[ky], $MachinePrecision]
NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
code[l_, Om_, kx$95$m_, ky$95$m_] := If[LessEqual[ky$95$m, 9.8e-191], N[Sqrt[N[(0.5 + N[(0.5 / N[Sqrt[N[(1.0 + N[(4.0 * N[(N[Power[N[(l * N[Sin[ky$95$m], $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision] / N[(Om * Om), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], N[Sqrt[N[(N[(1.0 / 2.0), $MachinePrecision] * N[(1.0 + N[(1.0 / N[Sqrt[N[(1.0 + N[(N[Power[N[(N[(2.0 * l), $MachinePrecision] / Om), $MachinePrecision], 2.0], $MachinePrecision] * N[(N[Power[N[Sin[kx$95$m], $MachinePrecision], 2.0], $MachinePrecision] + N[Power[N[Sin[ky$95$m], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}
kx_m = \left|kx\right|
\\
ky_m = \left|ky\right|
\\
[l, Om, kx_m, ky_m] = \mathsf{sort}([l, Om, kx_m, ky_m])\\
\\
\begin{array}{l}
\mathbf{if}\;ky\_m \leq 9.8 \cdot 10^{-191}:\\
\;\;\;\;\sqrt{0.5 + \frac{0.5}{\sqrt{1 + 4 \cdot \frac{{\left(\ell \cdot \sin ky\_m\right)}^{2}}{Om \cdot Om}}}}\\

\mathbf{else}:\\
\;\;\;\;\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx\_m}^{2} + {\sin ky\_m}^{2}\right)}}\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if ky < 9.7999999999999999e-191

    1. Initial program 71.3%

      \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
    2. Applied rewrites71.3%

      \[\leadsto \sqrt{\color{blue}{0.5 + \frac{1}{\sqrt{\mathsf{fma}\left(\left(0.5 - 0.5 \cdot \cos \left(2 \cdot ky\right)\right) + \left(0.5 - 0.5 \cdot \cos \left(2 \cdot kx\right)\right), \frac{\ell + \ell}{Om} \cdot \frac{\ell + \ell}{Om}, 1\right)}} \cdot 0.5}} \]
    3. Taylor expanded in kx around 0

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

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

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{{\ell}^{2} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}{{Om}^{2}}}}} \]
      3. lower-+.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{{\ell}^{2} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}{{Om}^{2}}}}} \]
      4. lower-*.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{{\ell}^{2} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}{{Om}^{2}}}}} \]
      5. lower-/.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{{\ell}^{2} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}{{Om}^{2}}}}} \]
    5. Applied rewrites54.9%

      \[\leadsto \sqrt{0.5 + \color{blue}{\frac{0.5}{\sqrt{1 + 4 \cdot \frac{\left(\ell \cdot \ell\right) \cdot \left(0.5 - 0.5 \cdot \cos \left(2 \cdot ky\right)\right)}{Om \cdot Om}}}}} \]
    6. Step-by-step derivation
      1. metadata-evalN/A

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{\left(\ell \cdot \ell\right) \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}{Om \cdot Om}}}} \]
      2. metadata-evalN/A

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{\left(\ell \cdot \ell\right) \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}{Om \cdot Om}}}} \]
      3. lift-*.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{\left(\ell \cdot \ell\right) \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}{Om \cdot Om}}}} \]
      4. lift-*.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{\left(\ell \cdot \ell\right) \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}{Om \cdot Om}}}} \]
      5. pow2N/A

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{{\ell}^{2} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}{Om \cdot Om}}}} \]
      6. lift--.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{{\ell}^{2} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}{Om \cdot Om}}}} \]
      7. metadata-evalN/A

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{{\ell}^{2} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}{Om \cdot Om}}}} \]
      8. lift-*.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{{\ell}^{2} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}{Om \cdot Om}}}} \]
      9. metadata-evalN/A

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{{\ell}^{2} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}{Om \cdot Om}}}} \]
      10. lift-*.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{{\ell}^{2} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}{Om \cdot Om}}}} \]
      11. lift-cos.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{{\ell}^{2} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}{Om \cdot Om}}}} \]
      12. sqr-sin-a-revN/A

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{{\ell}^{2} \cdot \left(\sin ky \cdot \sin ky\right)}{Om \cdot Om}}}} \]
      13. unpow2N/A

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{{\ell}^{2} \cdot {\sin ky}^{2}}{Om \cdot Om}}}} \]
      14. pow-prod-downN/A

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{{\left(\ell \cdot \sin ky\right)}^{2}}{Om \cdot Om}}}} \]
      15. lower-pow.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{{\left(\ell \cdot \sin ky\right)}^{2}}{Om \cdot Om}}}} \]
      16. lower-*.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} + \frac{\frac{1}{2}}{\sqrt{1 + 4 \cdot \frac{{\left(\ell \cdot \sin ky\right)}^{2}}{Om \cdot Om}}}} \]
      17. lower-sin.f6483.2

        \[\leadsto \sqrt{0.5 + \frac{0.5}{\sqrt{1 + 4 \cdot \frac{{\left(\ell \cdot \sin ky\right)}^{2}}{Om \cdot Om}}}} \]
    7. Applied rewrites83.2%

      \[\leadsto \sqrt{0.5 + \frac{0.5}{\sqrt{1 + 4 \cdot \frac{{\left(\ell \cdot \sin ky\right)}^{2}}{Om \cdot Om}}}} \]

    if 9.7999999999999999e-191 < ky

    1. Initial program 99.3%

      \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 2: 98.8% accurate, 0.6× speedup?

\[\begin{array}{l} kx_m = \left|kx\right| \\ ky_m = \left|ky\right| \\ [l, Om, kx_m, ky_m] = \mathsf{sort}([l, Om, kx_m, ky_m])\\ \\ \begin{array}{l} t_0 := \frac{\ell + \ell}{Om}\\ \mathbf{if}\;\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx\_m}^{2} + {\sin ky\_m}^{2}\right)} \leq 10000000000000:\\ \;\;\;\;\sqrt{0.5 + \frac{1}{\sqrt{\mathsf{fma}\left(\left(0.5 - 0.5 \cdot \cos \left(2 \cdot ky\_m\right)\right) + \left(0.5 - 0.5 \cdot \cos \left(2 \cdot kx\_m\right)\right), t\_0 \cdot t\_0, 1\right)}} \cdot 0.5}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{0.5}\\ \end{array} \end{array} \]
kx_m = (fabs.f64 kx)
ky_m = (fabs.f64 ky)
NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
(FPCore (l Om kx_m ky_m)
 :precision binary64
 (let* ((t_0 (/ (+ l l) Om)))
   (if (<=
        (sqrt
         (+
          1.0
          (*
           (pow (/ (* 2.0 l) Om) 2.0)
           (+ (pow (sin kx_m) 2.0) (pow (sin ky_m) 2.0)))))
        10000000000000.0)
     (sqrt
      (+
       0.5
       (*
        (/
         1.0
         (sqrt
          (fma
           (+
            (- 0.5 (* 0.5 (cos (* 2.0 ky_m))))
            (- 0.5 (* 0.5 (cos (* 2.0 kx_m)))))
           (* t_0 t_0)
           1.0)))
        0.5)))
     (sqrt 0.5))))
kx_m = fabs(kx);
ky_m = fabs(ky);
assert(l < Om && Om < kx_m && kx_m < ky_m);
double code(double l, double Om, double kx_m, double ky_m) {
	double t_0 = (l + l) / Om;
	double tmp;
	if (sqrt((1.0 + (pow(((2.0 * l) / Om), 2.0) * (pow(sin(kx_m), 2.0) + pow(sin(ky_m), 2.0))))) <= 10000000000000.0) {
		tmp = sqrt((0.5 + ((1.0 / sqrt(fma(((0.5 - (0.5 * cos((2.0 * ky_m)))) + (0.5 - (0.5 * cos((2.0 * kx_m))))), (t_0 * t_0), 1.0))) * 0.5)));
	} else {
		tmp = sqrt(0.5);
	}
	return tmp;
}
kx_m = abs(kx)
ky_m = abs(ky)
l, Om, kx_m, ky_m = sort([l, Om, kx_m, ky_m])
function code(l, Om, kx_m, ky_m)
	t_0 = Float64(Float64(l + l) / Om)
	tmp = 0.0
	if (sqrt(Float64(1.0 + Float64((Float64(Float64(2.0 * l) / Om) ^ 2.0) * Float64((sin(kx_m) ^ 2.0) + (sin(ky_m) ^ 2.0))))) <= 10000000000000.0)
		tmp = sqrt(Float64(0.5 + Float64(Float64(1.0 / sqrt(fma(Float64(Float64(0.5 - Float64(0.5 * cos(Float64(2.0 * ky_m)))) + Float64(0.5 - Float64(0.5 * cos(Float64(2.0 * kx_m))))), Float64(t_0 * t_0), 1.0))) * 0.5)));
	else
		tmp = sqrt(0.5);
	end
	return tmp
end
kx_m = N[Abs[kx], $MachinePrecision]
ky_m = N[Abs[ky], $MachinePrecision]
NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
code[l_, Om_, kx$95$m_, ky$95$m_] := Block[{t$95$0 = N[(N[(l + l), $MachinePrecision] / Om), $MachinePrecision]}, If[LessEqual[N[Sqrt[N[(1.0 + N[(N[Power[N[(N[(2.0 * l), $MachinePrecision] / Om), $MachinePrecision], 2.0], $MachinePrecision] * N[(N[Power[N[Sin[kx$95$m], $MachinePrecision], 2.0], $MachinePrecision] + N[Power[N[Sin[ky$95$m], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], 10000000000000.0], N[Sqrt[N[(0.5 + N[(N[(1.0 / N[Sqrt[N[(N[(N[(0.5 - N[(0.5 * N[Cos[N[(2.0 * ky$95$m), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.5 - N[(0.5 * N[Cos[N[(2.0 * kx$95$m), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(t$95$0 * t$95$0), $MachinePrecision] + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], N[Sqrt[0.5], $MachinePrecision]]]
\begin{array}{l}
kx_m = \left|kx\right|
\\
ky_m = \left|ky\right|
\\
[l, Om, kx_m, ky_m] = \mathsf{sort}([l, Om, kx_m, ky_m])\\
\\
\begin{array}{l}
t_0 := \frac{\ell + \ell}{Om}\\
\mathbf{if}\;\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx\_m}^{2} + {\sin ky\_m}^{2}\right)} \leq 10000000000000:\\
\;\;\;\;\sqrt{0.5 + \frac{1}{\sqrt{\mathsf{fma}\left(\left(0.5 - 0.5 \cdot \cos \left(2 \cdot ky\_m\right)\right) + \left(0.5 - 0.5 \cdot \cos \left(2 \cdot kx\_m\right)\right), t\_0 \cdot t\_0, 1\right)}} \cdot 0.5}\\

\mathbf{else}:\\
\;\;\;\;\sqrt{0.5}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (sqrt.f64 (+.f64 #s(literal 1 binary64) (*.f64 (pow.f64 (/.f64 (*.f64 #s(literal 2 binary64) l) Om) #s(literal 2 binary64)) (+.f64 (pow.f64 (sin.f64 kx) #s(literal 2 binary64)) (pow.f64 (sin.f64 ky) #s(literal 2 binary64)))))) < 1e13

    1. Initial program 100.0%

      \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
    2. Applied rewrites99.2%

      \[\leadsto \sqrt{\color{blue}{0.5 + \frac{1}{\sqrt{\mathsf{fma}\left(\left(0.5 - 0.5 \cdot \cos \left(2 \cdot ky\right)\right) + \left(0.5 - 0.5 \cdot \cos \left(2 \cdot kx\right)\right), \frac{\ell + \ell}{Om} \cdot \frac{\ell + \ell}{Om}, 1\right)}} \cdot 0.5}} \]

    if 1e13 < (sqrt.f64 (+.f64 #s(literal 1 binary64) (*.f64 (pow.f64 (/.f64 (*.f64 #s(literal 2 binary64) l) Om) #s(literal 2 binary64)) (+.f64 (pow.f64 (sin.f64 kx) #s(literal 2 binary64)) (pow.f64 (sin.f64 ky) #s(literal 2 binary64))))))

    1. Initial program 96.4%

      \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
    2. Taylor expanded in l around inf

      \[\leadsto \sqrt{\color{blue}{\frac{1}{2}}} \]
    3. Step-by-step derivation
      1. Applied rewrites99.3%

        \[\leadsto \sqrt{\color{blue}{0.5}} \]
    4. Recombined 2 regimes into one program.
    5. Add Preprocessing

    Alternative 3: 98.4% accurate, 0.7× speedup?

    \[\begin{array}{l} kx_m = \left|kx\right| \\ ky_m = \left|ky\right| \\ [l, Om, kx_m, ky_m] = \mathsf{sort}([l, Om, kx_m, ky_m])\\ \\ \begin{array}{l} t_0 := \frac{\ell + \ell}{Om}\\ \mathbf{if}\;\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx\_m}^{2} + {\sin ky\_m}^{2}\right)} \leq 2:\\ \;\;\;\;\sqrt{0.5 + \frac{1}{\sqrt{\mathsf{fma}\left(0.5 - 0.5 \cdot \cos \left(2 \cdot kx\_m\right), t\_0 \cdot t\_0, 1\right)}} \cdot 0.5}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{0.5}\\ \end{array} \end{array} \]
    kx_m = (fabs.f64 kx)
    ky_m = (fabs.f64 ky)
    NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
    (FPCore (l Om kx_m ky_m)
     :precision binary64
     (let* ((t_0 (/ (+ l l) Om)))
       (if (<=
            (sqrt
             (+
              1.0
              (*
               (pow (/ (* 2.0 l) Om) 2.0)
               (+ (pow (sin kx_m) 2.0) (pow (sin ky_m) 2.0)))))
            2.0)
         (sqrt
          (+
           0.5
           (*
            (/ 1.0 (sqrt (fma (- 0.5 (* 0.5 (cos (* 2.0 kx_m)))) (* t_0 t_0) 1.0)))
            0.5)))
         (sqrt 0.5))))
    kx_m = fabs(kx);
    ky_m = fabs(ky);
    assert(l < Om && Om < kx_m && kx_m < ky_m);
    double code(double l, double Om, double kx_m, double ky_m) {
    	double t_0 = (l + l) / Om;
    	double tmp;
    	if (sqrt((1.0 + (pow(((2.0 * l) / Om), 2.0) * (pow(sin(kx_m), 2.0) + pow(sin(ky_m), 2.0))))) <= 2.0) {
    		tmp = sqrt((0.5 + ((1.0 / sqrt(fma((0.5 - (0.5 * cos((2.0 * kx_m)))), (t_0 * t_0), 1.0))) * 0.5)));
    	} else {
    		tmp = sqrt(0.5);
    	}
    	return tmp;
    }
    
    kx_m = abs(kx)
    ky_m = abs(ky)
    l, Om, kx_m, ky_m = sort([l, Om, kx_m, ky_m])
    function code(l, Om, kx_m, ky_m)
    	t_0 = Float64(Float64(l + l) / Om)
    	tmp = 0.0
    	if (sqrt(Float64(1.0 + Float64((Float64(Float64(2.0 * l) / Om) ^ 2.0) * Float64((sin(kx_m) ^ 2.0) + (sin(ky_m) ^ 2.0))))) <= 2.0)
    		tmp = sqrt(Float64(0.5 + Float64(Float64(1.0 / sqrt(fma(Float64(0.5 - Float64(0.5 * cos(Float64(2.0 * kx_m)))), Float64(t_0 * t_0), 1.0))) * 0.5)));
    	else
    		tmp = sqrt(0.5);
    	end
    	return tmp
    end
    
    kx_m = N[Abs[kx], $MachinePrecision]
    ky_m = N[Abs[ky], $MachinePrecision]
    NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
    code[l_, Om_, kx$95$m_, ky$95$m_] := Block[{t$95$0 = N[(N[(l + l), $MachinePrecision] / Om), $MachinePrecision]}, If[LessEqual[N[Sqrt[N[(1.0 + N[(N[Power[N[(N[(2.0 * l), $MachinePrecision] / Om), $MachinePrecision], 2.0], $MachinePrecision] * N[(N[Power[N[Sin[kx$95$m], $MachinePrecision], 2.0], $MachinePrecision] + N[Power[N[Sin[ky$95$m], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], 2.0], N[Sqrt[N[(0.5 + N[(N[(1.0 / N[Sqrt[N[(N[(0.5 - N[(0.5 * N[Cos[N[(2.0 * kx$95$m), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(t$95$0 * t$95$0), $MachinePrecision] + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], N[Sqrt[0.5], $MachinePrecision]]]
    
    \begin{array}{l}
    kx_m = \left|kx\right|
    \\
    ky_m = \left|ky\right|
    \\
    [l, Om, kx_m, ky_m] = \mathsf{sort}([l, Om, kx_m, ky_m])\\
    \\
    \begin{array}{l}
    t_0 := \frac{\ell + \ell}{Om}\\
    \mathbf{if}\;\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx\_m}^{2} + {\sin ky\_m}^{2}\right)} \leq 2:\\
    \;\;\;\;\sqrt{0.5 + \frac{1}{\sqrt{\mathsf{fma}\left(0.5 - 0.5 \cdot \cos \left(2 \cdot kx\_m\right), t\_0 \cdot t\_0, 1\right)}} \cdot 0.5}\\
    
    \mathbf{else}:\\
    \;\;\;\;\sqrt{0.5}\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (sqrt.f64 (+.f64 #s(literal 1 binary64) (*.f64 (pow.f64 (/.f64 (*.f64 #s(literal 2 binary64) l) Om) #s(literal 2 binary64)) (+.f64 (pow.f64 (sin.f64 kx) #s(literal 2 binary64)) (pow.f64 (sin.f64 ky) #s(literal 2 binary64)))))) < 2

      1. Initial program 100.0%

        \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
      2. Applied rewrites99.7%

        \[\leadsto \sqrt{\color{blue}{0.5 + \frac{1}{\sqrt{\mathsf{fma}\left(\left(0.5 - 0.5 \cdot \cos \left(2 \cdot ky\right)\right) + \left(0.5 - 0.5 \cdot \cos \left(2 \cdot kx\right)\right), \frac{\ell + \ell}{Om} \cdot \frac{\ell + \ell}{Om}, 1\right)}} \cdot 0.5}} \]
      3. Taylor expanded in ky around 0

        \[\leadsto \sqrt{\frac{1}{2} + \frac{1}{\sqrt{\mathsf{fma}\left(\color{blue}{\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot kx\right)}, \frac{\ell + \ell}{Om} \cdot \frac{\ell + \ell}{Om}, 1\right)}} \cdot \frac{1}{2}} \]
      4. Step-by-step derivation
        1. lift-cos.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot kx\right), \frac{\ell + \ell}{Om} \cdot \frac{\ell + \ell}{Om}, 1\right)}} \cdot \frac{1}{2}} \]
        2. lift-*.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot kx\right), \frac{\ell + \ell}{Om} \cdot \frac{\ell + \ell}{Om}, 1\right)}} \cdot \frac{1}{2}} \]
        3. lift-*.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{1}{2} - \frac{1}{2} \cdot \color{blue}{\cos \left(2 \cdot kx\right)}, \frac{\ell + \ell}{Om} \cdot \frac{\ell + \ell}{Om}, 1\right)}} \cdot \frac{1}{2}} \]
        4. lift--.f6499.1

          \[\leadsto \sqrt{0.5 + \frac{1}{\sqrt{\mathsf{fma}\left(0.5 - \color{blue}{0.5 \cdot \cos \left(2 \cdot kx\right)}, \frac{\ell + \ell}{Om} \cdot \frac{\ell + \ell}{Om}, 1\right)}} \cdot 0.5} \]
      5. Applied rewrites99.1%

        \[\leadsto \sqrt{0.5 + \frac{1}{\sqrt{\mathsf{fma}\left(\color{blue}{0.5 - 0.5 \cdot \cos \left(2 \cdot kx\right)}, \frac{\ell + \ell}{Om} \cdot \frac{\ell + \ell}{Om}, 1\right)}} \cdot 0.5} \]

      if 2 < (sqrt.f64 (+.f64 #s(literal 1 binary64) (*.f64 (pow.f64 (/.f64 (*.f64 #s(literal 2 binary64) l) Om) #s(literal 2 binary64)) (+.f64 (pow.f64 (sin.f64 kx) #s(literal 2 binary64)) (pow.f64 (sin.f64 ky) #s(literal 2 binary64))))))

      1. Initial program 96.5%

        \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
      2. Taylor expanded in l around inf

        \[\leadsto \sqrt{\color{blue}{\frac{1}{2}}} \]
      3. Step-by-step derivation
        1. Applied rewrites97.5%

          \[\leadsto \sqrt{\color{blue}{0.5}} \]
      4. Recombined 2 regimes into one program.
      5. Add Preprocessing

      Alternative 4: 98.4% accurate, 1.1× speedup?

      \[\begin{array}{l} kx_m = \left|kx\right| \\ ky_m = \left|ky\right| \\ [l, Om, kx_m, ky_m] = \mathsf{sort}([l, Om, kx_m, ky_m])\\ \\ \begin{array}{l} \mathbf{if}\;\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx\_m}^{2} + {\sin ky\_m}^{2}\right)} \leq 2:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;\sqrt{0.5}\\ \end{array} \end{array} \]
      kx_m = (fabs.f64 kx)
      ky_m = (fabs.f64 ky)
      NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
      (FPCore (l Om kx_m ky_m)
       :precision binary64
       (if (<=
            (sqrt
             (+
              1.0
              (*
               (pow (/ (* 2.0 l) Om) 2.0)
               (+ (pow (sin kx_m) 2.0) (pow (sin ky_m) 2.0)))))
            2.0)
         1.0
         (sqrt 0.5)))
      kx_m = fabs(kx);
      ky_m = fabs(ky);
      assert(l < Om && Om < kx_m && kx_m < ky_m);
      double code(double l, double Om, double kx_m, double ky_m) {
      	double tmp;
      	if (sqrt((1.0 + (pow(((2.0 * l) / Om), 2.0) * (pow(sin(kx_m), 2.0) + pow(sin(ky_m), 2.0))))) <= 2.0) {
      		tmp = 1.0;
      	} else {
      		tmp = sqrt(0.5);
      	}
      	return tmp;
      }
      
      kx_m =     private
      ky_m =     private
      NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
      module fmin_fmax_functions
          implicit none
          private
          public fmax
          public fmin
      
          interface fmax
              module procedure fmax88
              module procedure fmax44
              module procedure fmax84
              module procedure fmax48
          end interface
          interface fmin
              module procedure fmin88
              module procedure fmin44
              module procedure fmin84
              module procedure fmin48
          end interface
      contains
          real(8) function fmax88(x, y) result (res)
              real(8), intent (in) :: x
              real(8), intent (in) :: y
              res = merge(y, merge(x, max(x, y), y /= y), x /= x)
          end function
          real(4) function fmax44(x, y) result (res)
              real(4), intent (in) :: x
              real(4), intent (in) :: y
              res = merge(y, merge(x, max(x, y), y /= y), x /= x)
          end function
          real(8) function fmax84(x, y) result(res)
              real(8), intent (in) :: x
              real(4), intent (in) :: y
              res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
          end function
          real(8) function fmax48(x, y) result(res)
              real(4), intent (in) :: x
              real(8), intent (in) :: y
              res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
          end function
          real(8) function fmin88(x, y) result (res)
              real(8), intent (in) :: x
              real(8), intent (in) :: y
              res = merge(y, merge(x, min(x, y), y /= y), x /= x)
          end function
          real(4) function fmin44(x, y) result (res)
              real(4), intent (in) :: x
              real(4), intent (in) :: y
              res = merge(y, merge(x, min(x, y), y /= y), x /= x)
          end function
          real(8) function fmin84(x, y) result(res)
              real(8), intent (in) :: x
              real(4), intent (in) :: y
              res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
          end function
          real(8) function fmin48(x, y) result(res)
              real(4), intent (in) :: x
              real(8), intent (in) :: y
              res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
          end function
      end module
      
      real(8) function code(l, om, kx_m, ky_m)
      use fmin_fmax_functions
          real(8), intent (in) :: l
          real(8), intent (in) :: om
          real(8), intent (in) :: kx_m
          real(8), intent (in) :: ky_m
          real(8) :: tmp
          if (sqrt((1.0d0 + ((((2.0d0 * l) / om) ** 2.0d0) * ((sin(kx_m) ** 2.0d0) + (sin(ky_m) ** 2.0d0))))) <= 2.0d0) then
              tmp = 1.0d0
          else
              tmp = sqrt(0.5d0)
          end if
          code = tmp
      end function
      
      kx_m = Math.abs(kx);
      ky_m = Math.abs(ky);
      assert l < Om && Om < kx_m && kx_m < ky_m;
      public static double code(double l, double Om, double kx_m, double ky_m) {
      	double tmp;
      	if (Math.sqrt((1.0 + (Math.pow(((2.0 * l) / Om), 2.0) * (Math.pow(Math.sin(kx_m), 2.0) + Math.pow(Math.sin(ky_m), 2.0))))) <= 2.0) {
      		tmp = 1.0;
      	} else {
      		tmp = Math.sqrt(0.5);
      	}
      	return tmp;
      }
      
      kx_m = math.fabs(kx)
      ky_m = math.fabs(ky)
      [l, Om, kx_m, ky_m] = sort([l, Om, kx_m, ky_m])
      def code(l, Om, kx_m, ky_m):
      	tmp = 0
      	if math.sqrt((1.0 + (math.pow(((2.0 * l) / Om), 2.0) * (math.pow(math.sin(kx_m), 2.0) + math.pow(math.sin(ky_m), 2.0))))) <= 2.0:
      		tmp = 1.0
      	else:
      		tmp = math.sqrt(0.5)
      	return tmp
      
      kx_m = abs(kx)
      ky_m = abs(ky)
      l, Om, kx_m, ky_m = sort([l, Om, kx_m, ky_m])
      function code(l, Om, kx_m, ky_m)
      	tmp = 0.0
      	if (sqrt(Float64(1.0 + Float64((Float64(Float64(2.0 * l) / Om) ^ 2.0) * Float64((sin(kx_m) ^ 2.0) + (sin(ky_m) ^ 2.0))))) <= 2.0)
      		tmp = 1.0;
      	else
      		tmp = sqrt(0.5);
      	end
      	return tmp
      end
      
      kx_m = abs(kx);
      ky_m = abs(ky);
      l, Om, kx_m, ky_m = num2cell(sort([l, Om, kx_m, ky_m])){:}
      function tmp_2 = code(l, Om, kx_m, ky_m)
      	tmp = 0.0;
      	if (sqrt((1.0 + ((((2.0 * l) / Om) ^ 2.0) * ((sin(kx_m) ^ 2.0) + (sin(ky_m) ^ 2.0))))) <= 2.0)
      		tmp = 1.0;
      	else
      		tmp = sqrt(0.5);
      	end
      	tmp_2 = tmp;
      end
      
      kx_m = N[Abs[kx], $MachinePrecision]
      ky_m = N[Abs[ky], $MachinePrecision]
      NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
      code[l_, Om_, kx$95$m_, ky$95$m_] := If[LessEqual[N[Sqrt[N[(1.0 + N[(N[Power[N[(N[(2.0 * l), $MachinePrecision] / Om), $MachinePrecision], 2.0], $MachinePrecision] * N[(N[Power[N[Sin[kx$95$m], $MachinePrecision], 2.0], $MachinePrecision] + N[Power[N[Sin[ky$95$m], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], 2.0], 1.0, N[Sqrt[0.5], $MachinePrecision]]
      
      \begin{array}{l}
      kx_m = \left|kx\right|
      \\
      ky_m = \left|ky\right|
      \\
      [l, Om, kx_m, ky_m] = \mathsf{sort}([l, Om, kx_m, ky_m])\\
      \\
      \begin{array}{l}
      \mathbf{if}\;\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx\_m}^{2} + {\sin ky\_m}^{2}\right)} \leq 2:\\
      \;\;\;\;1\\
      
      \mathbf{else}:\\
      \;\;\;\;\sqrt{0.5}\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (sqrt.f64 (+.f64 #s(literal 1 binary64) (*.f64 (pow.f64 (/.f64 (*.f64 #s(literal 2 binary64) l) Om) #s(literal 2 binary64)) (+.f64 (pow.f64 (sin.f64 kx) #s(literal 2 binary64)) (pow.f64 (sin.f64 ky) #s(literal 2 binary64)))))) < 2

        1. Initial program 100.0%

          \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
        2. Taylor expanded in l around 0

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

            \[\leadsto \color{blue}{1} \]

          if 2 < (sqrt.f64 (+.f64 #s(literal 1 binary64) (*.f64 (pow.f64 (/.f64 (*.f64 #s(literal 2 binary64) l) Om) #s(literal 2 binary64)) (+.f64 (pow.f64 (sin.f64 kx) #s(literal 2 binary64)) (pow.f64 (sin.f64 ky) #s(literal 2 binary64))))))

          1. Initial program 96.5%

            \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
          2. Taylor expanded in l around inf

            \[\leadsto \sqrt{\color{blue}{\frac{1}{2}}} \]
          3. Step-by-step derivation
            1. Applied rewrites97.5%

              \[\leadsto \sqrt{\color{blue}{0.5}} \]
          4. Recombined 2 regimes into one program.
          5. Add Preprocessing

          Alternative 5: 62.1% accurate, 142.7× speedup?

          \[\begin{array}{l} kx_m = \left|kx\right| \\ ky_m = \left|ky\right| \\ [l, Om, kx_m, ky_m] = \mathsf{sort}([l, Om, kx_m, ky_m])\\ \\ 1 \end{array} \]
          kx_m = (fabs.f64 kx)
          ky_m = (fabs.f64 ky)
          NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
          (FPCore (l Om kx_m ky_m) :precision binary64 1.0)
          kx_m = fabs(kx);
          ky_m = fabs(ky);
          assert(l < Om && Om < kx_m && kx_m < ky_m);
          double code(double l, double Om, double kx_m, double ky_m) {
          	return 1.0;
          }
          
          kx_m =     private
          ky_m =     private
          NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
          module fmin_fmax_functions
              implicit none
              private
              public fmax
              public fmin
          
              interface fmax
                  module procedure fmax88
                  module procedure fmax44
                  module procedure fmax84
                  module procedure fmax48
              end interface
              interface fmin
                  module procedure fmin88
                  module procedure fmin44
                  module procedure fmin84
                  module procedure fmin48
              end interface
          contains
              real(8) function fmax88(x, y) result (res)
                  real(8), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
              end function
              real(4) function fmax44(x, y) result (res)
                  real(4), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
              end function
              real(8) function fmax84(x, y) result(res)
                  real(8), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
              end function
              real(8) function fmax48(x, y) result(res)
                  real(4), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
              end function
              real(8) function fmin88(x, y) result (res)
                  real(8), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
              end function
              real(4) function fmin44(x, y) result (res)
                  real(4), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
              end function
              real(8) function fmin84(x, y) result(res)
                  real(8), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
              end function
              real(8) function fmin48(x, y) result(res)
                  real(4), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
              end function
          end module
          
          real(8) function code(l, om, kx_m, ky_m)
          use fmin_fmax_functions
              real(8), intent (in) :: l
              real(8), intent (in) :: om
              real(8), intent (in) :: kx_m
              real(8), intent (in) :: ky_m
              code = 1.0d0
          end function
          
          kx_m = Math.abs(kx);
          ky_m = Math.abs(ky);
          assert l < Om && Om < kx_m && kx_m < ky_m;
          public static double code(double l, double Om, double kx_m, double ky_m) {
          	return 1.0;
          }
          
          kx_m = math.fabs(kx)
          ky_m = math.fabs(ky)
          [l, Om, kx_m, ky_m] = sort([l, Om, kx_m, ky_m])
          def code(l, Om, kx_m, ky_m):
          	return 1.0
          
          kx_m = abs(kx)
          ky_m = abs(ky)
          l, Om, kx_m, ky_m = sort([l, Om, kx_m, ky_m])
          function code(l, Om, kx_m, ky_m)
          	return 1.0
          end
          
          kx_m = abs(kx);
          ky_m = abs(ky);
          l, Om, kx_m, ky_m = num2cell(sort([l, Om, kx_m, ky_m])){:}
          function tmp = code(l, Om, kx_m, ky_m)
          	tmp = 1.0;
          end
          
          kx_m = N[Abs[kx], $MachinePrecision]
          ky_m = N[Abs[ky], $MachinePrecision]
          NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
          code[l_, Om_, kx$95$m_, ky$95$m_] := 1.0
          
          \begin{array}{l}
          kx_m = \left|kx\right|
          \\
          ky_m = \left|ky\right|
          \\
          [l, Om, kx_m, ky_m] = \mathsf{sort}([l, Om, kx_m, ky_m])\\
          \\
          1
          \end{array}
          
          Derivation
          1. Initial program 98.4%

            \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
          2. Taylor expanded in l around 0

            \[\leadsto \color{blue}{1} \]
          3. Step-by-step derivation
            1. Applied rewrites62.1%

              \[\leadsto \color{blue}{1} \]
            2. Add Preprocessing

            Reproduce

            ?
            herbie shell --seed 2025133 
            (FPCore (l Om kx ky)
              :name "Toniolo and Linder, Equation (3a)"
              :precision binary64
              (sqrt (* (/ 1.0 2.0) (+ 1.0 (/ 1.0 (sqrt (+ 1.0 (* (pow (/ (* 2.0 l) Om) 2.0) (+ (pow (sin kx) 2.0) (pow (sin ky) 2.0))))))))))