Equirectangular approximation to distance on a great circle

Percentage Accurate: 59.3% → 95.9%
Time: 4.9s
Alternatives: 11
Speedup: 4.3×

Specification

?
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\\ R \cdot \sqrt{t\_0 \cdot t\_0 + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \end{array} \end{array} \]
(FPCore (R lambda1 lambda2 phi1 phi2)
 :precision binary64
 (let* ((t_0 (* (- lambda1 lambda2) (cos (/ (+ phi1 phi2) 2.0)))))
   (* R (sqrt (+ (* t_0 t_0) (* (- phi1 phi2) (- phi1 phi2)))))))
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0));
	return R * sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))));
}
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(r, lambda1, lambda2, phi1, phi2)
use fmin_fmax_functions
    real(8), intent (in) :: r
    real(8), intent (in) :: lambda1
    real(8), intent (in) :: lambda2
    real(8), intent (in) :: phi1
    real(8), intent (in) :: phi2
    real(8) :: t_0
    t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0d0))
    code = r * sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))))
end function
public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double t_0 = (lambda1 - lambda2) * Math.cos(((phi1 + phi2) / 2.0));
	return R * Math.sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))));
}
def code(R, lambda1, lambda2, phi1, phi2):
	t_0 = (lambda1 - lambda2) * math.cos(((phi1 + phi2) / 2.0))
	return R * math.sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))))
function code(R, lambda1, lambda2, phi1, phi2)
	t_0 = Float64(Float64(lambda1 - lambda2) * cos(Float64(Float64(phi1 + phi2) / 2.0)))
	return Float64(R * sqrt(Float64(Float64(t_0 * t_0) + Float64(Float64(phi1 - phi2) * Float64(phi1 - phi2)))))
end
function tmp = code(R, lambda1, lambda2, phi1, phi2)
	t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0));
	tmp = R * sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))));
end
code[R_, lambda1_, lambda2_, phi1_, phi2_] := Block[{t$95$0 = N[(N[(lambda1 - lambda2), $MachinePrecision] * N[Cos[N[(N[(phi1 + phi2), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, N[(R * N[Sqrt[N[(N[(t$95$0 * t$95$0), $MachinePrecision] + N[(N[(phi1 - phi2), $MachinePrecision] * N[(phi1 - phi2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\\
R \cdot \sqrt{t\_0 \cdot t\_0 + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}
\end{array}
\end{array}

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 11 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: 59.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\\ R \cdot \sqrt{t\_0 \cdot t\_0 + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \end{array} \end{array} \]
(FPCore (R lambda1 lambda2 phi1 phi2)
 :precision binary64
 (let* ((t_0 (* (- lambda1 lambda2) (cos (/ (+ phi1 phi2) 2.0)))))
   (* R (sqrt (+ (* t_0 t_0) (* (- phi1 phi2) (- phi1 phi2)))))))
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0));
	return R * sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))));
}
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(r, lambda1, lambda2, phi1, phi2)
use fmin_fmax_functions
    real(8), intent (in) :: r
    real(8), intent (in) :: lambda1
    real(8), intent (in) :: lambda2
    real(8), intent (in) :: phi1
    real(8), intent (in) :: phi2
    real(8) :: t_0
    t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0d0))
    code = r * sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))))
end function
public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double t_0 = (lambda1 - lambda2) * Math.cos(((phi1 + phi2) / 2.0));
	return R * Math.sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))));
}
def code(R, lambda1, lambda2, phi1, phi2):
	t_0 = (lambda1 - lambda2) * math.cos(((phi1 + phi2) / 2.0))
	return R * math.sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))))
function code(R, lambda1, lambda2, phi1, phi2)
	t_0 = Float64(Float64(lambda1 - lambda2) * cos(Float64(Float64(phi1 + phi2) / 2.0)))
	return Float64(R * sqrt(Float64(Float64(t_0 * t_0) + Float64(Float64(phi1 - phi2) * Float64(phi1 - phi2)))))
end
function tmp = code(R, lambda1, lambda2, phi1, phi2)
	t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0));
	tmp = R * sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))));
end
code[R_, lambda1_, lambda2_, phi1_, phi2_] := Block[{t$95$0 = N[(N[(lambda1 - lambda2), $MachinePrecision] * N[Cos[N[(N[(phi1 + phi2), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, N[(R * N[Sqrt[N[(N[(t$95$0 * t$95$0), $MachinePrecision] + N[(N[(phi1 - phi2), $MachinePrecision] * N[(phi1 - phi2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\\
R \cdot \sqrt{t\_0 \cdot t\_0 + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}
\end{array}
\end{array}

Alternative 1: 95.9% accurate, 1.7× speedup?

\[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ \begin{array}{l} \mathbf{if}\;\phi_1 \leq -8.4 \cdot 10^{-5}:\\ \;\;\;\;\mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(0.5 \cdot \phi_2\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R\\ \end{array} \end{array} \]
NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
(FPCore (R lambda1 lambda2 phi1 phi2)
 :precision binary64
 (if (<= phi1 -8.4e-5)
   (* (hypot (- phi1 phi2) (* (cos (* 0.5 phi1)) (- lambda1 lambda2))) R)
   (* (hypot (- phi1 phi2) (* (cos (* 0.5 phi2)) (- lambda1 lambda2))) R)))
assert(R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2);
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double tmp;
	if (phi1 <= -8.4e-5) {
		tmp = hypot((phi1 - phi2), (cos((0.5 * phi1)) * (lambda1 - lambda2))) * R;
	} else {
		tmp = hypot((phi1 - phi2), (cos((0.5 * phi2)) * (lambda1 - lambda2))) * R;
	}
	return tmp;
}
assert R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2;
public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double tmp;
	if (phi1 <= -8.4e-5) {
		tmp = Math.hypot((phi1 - phi2), (Math.cos((0.5 * phi1)) * (lambda1 - lambda2))) * R;
	} else {
		tmp = Math.hypot((phi1 - phi2), (Math.cos((0.5 * phi2)) * (lambda1 - lambda2))) * R;
	}
	return tmp;
}
[R, lambda1, lambda2, phi1, phi2] = sort([R, lambda1, lambda2, phi1, phi2])
def code(R, lambda1, lambda2, phi1, phi2):
	tmp = 0
	if phi1 <= -8.4e-5:
		tmp = math.hypot((phi1 - phi2), (math.cos((0.5 * phi1)) * (lambda1 - lambda2))) * R
	else:
		tmp = math.hypot((phi1 - phi2), (math.cos((0.5 * phi2)) * (lambda1 - lambda2))) * R
	return tmp
R, lambda1, lambda2, phi1, phi2 = sort([R, lambda1, lambda2, phi1, phi2])
function code(R, lambda1, lambda2, phi1, phi2)
	tmp = 0.0
	if (phi1 <= -8.4e-5)
		tmp = Float64(hypot(Float64(phi1 - phi2), Float64(cos(Float64(0.5 * phi1)) * Float64(lambda1 - lambda2))) * R);
	else
		tmp = Float64(hypot(Float64(phi1 - phi2), Float64(cos(Float64(0.5 * phi2)) * Float64(lambda1 - lambda2))) * R);
	end
	return tmp
end
R, lambda1, lambda2, phi1, phi2 = num2cell(sort([R, lambda1, lambda2, phi1, phi2])){:}
function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
	tmp = 0.0;
	if (phi1 <= -8.4e-5)
		tmp = hypot((phi1 - phi2), (cos((0.5 * phi1)) * (lambda1 - lambda2))) * R;
	else
		tmp = hypot((phi1 - phi2), (cos((0.5 * phi2)) * (lambda1 - lambda2))) * R;
	end
	tmp_2 = tmp;
end
NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[LessEqual[phi1, -8.4e-5], N[(N[Sqrt[N[(phi1 - phi2), $MachinePrecision] ^ 2 + N[(N[Cos[N[(0.5 * phi1), $MachinePrecision]], $MachinePrecision] * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision] * R), $MachinePrecision], N[(N[Sqrt[N[(phi1 - phi2), $MachinePrecision] ^ 2 + N[(N[Cos[N[(0.5 * phi2), $MachinePrecision]], $MachinePrecision] * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision] * R), $MachinePrecision]]
\begin{array}{l}
[R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\
\\
\begin{array}{l}
\mathbf{if}\;\phi_1 \leq -8.4 \cdot 10^{-5}:\\
\;\;\;\;\mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R\\

\mathbf{else}:\\
\;\;\;\;\mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(0.5 \cdot \phi_2\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if phi1 < -8.39999999999999954e-5

    1. Initial program 53.0%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \color{blue}{R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
      2. lift-sqrt.f64N/A

        \[\leadsto R \cdot \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
      3. lift-+.f64N/A

        \[\leadsto R \cdot \sqrt{\color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
    3. Applied rewrites93.0%

      \[\leadsto \color{blue}{\mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(0.5 \cdot \left(\phi_2 + \phi_1\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R} \]
    4. Taylor expanded in phi1 around inf

      \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(\frac{1}{2} \cdot \color{blue}{\phi_1}\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
    5. Step-by-step derivation
      1. Applied rewrites93.0%

        \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(0.5 \cdot \color{blue}{\phi_1}\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]

      if -8.39999999999999954e-5 < phi1

      1. Initial program 64.3%

        \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
      2. Step-by-step derivation
        1. lift-*.f64N/A

          \[\leadsto \color{blue}{R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
        2. lift-sqrt.f64N/A

          \[\leadsto R \cdot \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
        3. lift-+.f64N/A

          \[\leadsto R \cdot \sqrt{\color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
      3. Applied rewrites98.1%

        \[\leadsto \color{blue}{\mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(0.5 \cdot \left(\phi_2 + \phi_1\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R} \]
      4. Taylor expanded in phi1 around 0

        \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(\frac{1}{2} \cdot \color{blue}{\phi_2}\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
      5. Step-by-step derivation
        1. Applied rewrites98.1%

          \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(0.5 \cdot \color{blue}{\phi_2}\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
      6. Recombined 2 regimes into one program.
      7. Add Preprocessing

      Alternative 2: 95.8% accurate, 1.7× speedup?

      \[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ \mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(0.5 \cdot \left(\phi_2 + \phi_1\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \end{array} \]
      NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
      (FPCore (R lambda1 lambda2 phi1 phi2)
       :precision binary64
       (*
        (hypot (- phi1 phi2) (* (cos (* 0.5 (+ phi2 phi1))) (- lambda1 lambda2)))
        R))
      assert(R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2);
      double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
      	return hypot((phi1 - phi2), (cos((0.5 * (phi2 + phi1))) * (lambda1 - lambda2))) * R;
      }
      
      assert R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2;
      public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
      	return Math.hypot((phi1 - phi2), (Math.cos((0.5 * (phi2 + phi1))) * (lambda1 - lambda2))) * R;
      }
      
      [R, lambda1, lambda2, phi1, phi2] = sort([R, lambda1, lambda2, phi1, phi2])
      def code(R, lambda1, lambda2, phi1, phi2):
      	return math.hypot((phi1 - phi2), (math.cos((0.5 * (phi2 + phi1))) * (lambda1 - lambda2))) * R
      
      R, lambda1, lambda2, phi1, phi2 = sort([R, lambda1, lambda2, phi1, phi2])
      function code(R, lambda1, lambda2, phi1, phi2)
      	return Float64(hypot(Float64(phi1 - phi2), Float64(cos(Float64(0.5 * Float64(phi2 + phi1))) * Float64(lambda1 - lambda2))) * R)
      end
      
      R, lambda1, lambda2, phi1, phi2 = num2cell(sort([R, lambda1, lambda2, phi1, phi2])){:}
      function tmp = code(R, lambda1, lambda2, phi1, phi2)
      	tmp = hypot((phi1 - phi2), (cos((0.5 * (phi2 + phi1))) * (lambda1 - lambda2))) * R;
      end
      
      NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
      code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(N[Sqrt[N[(phi1 - phi2), $MachinePrecision] ^ 2 + N[(N[Cos[N[(0.5 * N[(phi2 + phi1), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision] * R), $MachinePrecision]
      
      \begin{array}{l}
      [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\
      \\
      \mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(0.5 \cdot \left(\phi_2 + \phi_1\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R
      \end{array}
      
      Derivation
      1. Initial program 59.3%

        \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
      2. Step-by-step derivation
        1. lift-*.f64N/A

          \[\leadsto \color{blue}{R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
        2. lift-sqrt.f64N/A

          \[\leadsto R \cdot \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
        3. lift-+.f64N/A

          \[\leadsto R \cdot \sqrt{\color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
      3. Applied rewrites95.9%

        \[\leadsto \color{blue}{\mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(0.5 \cdot \left(\phi_2 + \phi_1\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R} \]
      4. Add Preprocessing

      Alternative 3: 90.3% accurate, 1.8× speedup?

      \[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ \mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \end{array} \]
      NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
      (FPCore (R lambda1 lambda2 phi1 phi2)
       :precision binary64
       (* (hypot (- phi1 phi2) (* (cos (* 0.5 phi1)) (- lambda1 lambda2))) R))
      assert(R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2);
      double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
      	return hypot((phi1 - phi2), (cos((0.5 * phi1)) * (lambda1 - lambda2))) * R;
      }
      
      assert R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2;
      public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
      	return Math.hypot((phi1 - phi2), (Math.cos((0.5 * phi1)) * (lambda1 - lambda2))) * R;
      }
      
      [R, lambda1, lambda2, phi1, phi2] = sort([R, lambda1, lambda2, phi1, phi2])
      def code(R, lambda1, lambda2, phi1, phi2):
      	return math.hypot((phi1 - phi2), (math.cos((0.5 * phi1)) * (lambda1 - lambda2))) * R
      
      R, lambda1, lambda2, phi1, phi2 = sort([R, lambda1, lambda2, phi1, phi2])
      function code(R, lambda1, lambda2, phi1, phi2)
      	return Float64(hypot(Float64(phi1 - phi2), Float64(cos(Float64(0.5 * phi1)) * Float64(lambda1 - lambda2))) * R)
      end
      
      R, lambda1, lambda2, phi1, phi2 = num2cell(sort([R, lambda1, lambda2, phi1, phi2])){:}
      function tmp = code(R, lambda1, lambda2, phi1, phi2)
      	tmp = hypot((phi1 - phi2), (cos((0.5 * phi1)) * (lambda1 - lambda2))) * R;
      end
      
      NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
      code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(N[Sqrt[N[(phi1 - phi2), $MachinePrecision] ^ 2 + N[(N[Cos[N[(0.5 * phi1), $MachinePrecision]], $MachinePrecision] * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision] * R), $MachinePrecision]
      
      \begin{array}{l}
      [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\
      \\
      \mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R
      \end{array}
      
      Derivation
      1. Initial program 59.3%

        \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
      2. Step-by-step derivation
        1. lift-*.f64N/A

          \[\leadsto \color{blue}{R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
        2. lift-sqrt.f64N/A

          \[\leadsto R \cdot \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
        3. lift-+.f64N/A

          \[\leadsto R \cdot \sqrt{\color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
      3. Applied rewrites95.9%

        \[\leadsto \color{blue}{\mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(0.5 \cdot \left(\phi_2 + \phi_1\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R} \]
      4. Taylor expanded in phi1 around inf

        \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(\frac{1}{2} \cdot \color{blue}{\phi_1}\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
      5. Step-by-step derivation
        1. Applied rewrites90.3%

          \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(0.5 \cdot \color{blue}{\phi_1}\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
        2. Add Preprocessing

        Alternative 4: 88.3% accurate, 1.7× speedup?

        \[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ \begin{array}{l} \mathbf{if}\;\phi_2 \leq 2 \cdot 10^{-246}:\\ \;\;\;\;\mathsf{hypot}\left(\phi_1, \cos \left(0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\mathsf{hypot}\left(\phi_1 - \phi_2, 1 \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R\\ \end{array} \end{array} \]
        NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
        (FPCore (R lambda1 lambda2 phi1 phi2)
         :precision binary64
         (if (<= phi2 2e-246)
           (* (hypot phi1 (* (cos (* 0.5 phi1)) (- lambda1 lambda2))) R)
           (* (hypot (- phi1 phi2) (* 1.0 (- lambda1 lambda2))) R)))
        assert(R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2);
        double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
        	double tmp;
        	if (phi2 <= 2e-246) {
        		tmp = hypot(phi1, (cos((0.5 * phi1)) * (lambda1 - lambda2))) * R;
        	} else {
        		tmp = hypot((phi1 - phi2), (1.0 * (lambda1 - lambda2))) * R;
        	}
        	return tmp;
        }
        
        assert R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2;
        public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
        	double tmp;
        	if (phi2 <= 2e-246) {
        		tmp = Math.hypot(phi1, (Math.cos((0.5 * phi1)) * (lambda1 - lambda2))) * R;
        	} else {
        		tmp = Math.hypot((phi1 - phi2), (1.0 * (lambda1 - lambda2))) * R;
        	}
        	return tmp;
        }
        
        [R, lambda1, lambda2, phi1, phi2] = sort([R, lambda1, lambda2, phi1, phi2])
        def code(R, lambda1, lambda2, phi1, phi2):
        	tmp = 0
        	if phi2 <= 2e-246:
        		tmp = math.hypot(phi1, (math.cos((0.5 * phi1)) * (lambda1 - lambda2))) * R
        	else:
        		tmp = math.hypot((phi1 - phi2), (1.0 * (lambda1 - lambda2))) * R
        	return tmp
        
        R, lambda1, lambda2, phi1, phi2 = sort([R, lambda1, lambda2, phi1, phi2])
        function code(R, lambda1, lambda2, phi1, phi2)
        	tmp = 0.0
        	if (phi2 <= 2e-246)
        		tmp = Float64(hypot(phi1, Float64(cos(Float64(0.5 * phi1)) * Float64(lambda1 - lambda2))) * R);
        	else
        		tmp = Float64(hypot(Float64(phi1 - phi2), Float64(1.0 * Float64(lambda1 - lambda2))) * R);
        	end
        	return tmp
        end
        
        R, lambda1, lambda2, phi1, phi2 = num2cell(sort([R, lambda1, lambda2, phi1, phi2])){:}
        function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
        	tmp = 0.0;
        	if (phi2 <= 2e-246)
        		tmp = hypot(phi1, (cos((0.5 * phi1)) * (lambda1 - lambda2))) * R;
        	else
        		tmp = hypot((phi1 - phi2), (1.0 * (lambda1 - lambda2))) * R;
        	end
        	tmp_2 = tmp;
        end
        
        NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
        code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[LessEqual[phi2, 2e-246], N[(N[Sqrt[phi1 ^ 2 + N[(N[Cos[N[(0.5 * phi1), $MachinePrecision]], $MachinePrecision] * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision] * R), $MachinePrecision], N[(N[Sqrt[N[(phi1 - phi2), $MachinePrecision] ^ 2 + N[(1.0 * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision] * R), $MachinePrecision]]
        
        \begin{array}{l}
        [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\
        \\
        \begin{array}{l}
        \mathbf{if}\;\phi_2 \leq 2 \cdot 10^{-246}:\\
        \;\;\;\;\mathsf{hypot}\left(\phi_1, \cos \left(0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R\\
        
        \mathbf{else}:\\
        \;\;\;\;\mathsf{hypot}\left(\phi_1 - \phi_2, 1 \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if phi2 < 1.99999999999999991e-246

          1. Initial program 59.2%

            \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
          2. Step-by-step derivation
            1. lift-*.f64N/A

              \[\leadsto \color{blue}{R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
            2. lift-sqrt.f64N/A

              \[\leadsto R \cdot \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
            3. lift-+.f64N/A

              \[\leadsto R \cdot \sqrt{\color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
          3. Applied rewrites96.2%

            \[\leadsto \color{blue}{\mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(0.5 \cdot \left(\phi_2 + \phi_1\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R} \]
          4. Taylor expanded in phi1 around inf

            \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(\frac{1}{2} \cdot \color{blue}{\phi_1}\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
          5. Step-by-step derivation
            1. Applied rewrites96.2%

              \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(0.5 \cdot \color{blue}{\phi_1}\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
            2. Taylor expanded in phi1 around inf

              \[\leadsto \mathsf{hypot}\left(\color{blue}{\phi_1}, \cos \left(\frac{1}{2} \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
            3. Step-by-step derivation
              1. Applied rewrites95.7%

                \[\leadsto \mathsf{hypot}\left(\color{blue}{\phi_1}, \cos \left(0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]

              if 1.99999999999999991e-246 < phi2

              1. Initial program 59.4%

                \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
              2. Step-by-step derivation
                1. lift-*.f64N/A

                  \[\leadsto \color{blue}{R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
                2. lift-sqrt.f64N/A

                  \[\leadsto R \cdot \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
                3. lift-+.f64N/A

                  \[\leadsto R \cdot \sqrt{\color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
              3. Applied rewrites95.7%

                \[\leadsto \color{blue}{\mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(0.5 \cdot \left(\phi_2 + \phi_1\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R} \]
              4. Taylor expanded in phi1 around 0

                \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \color{blue}{\left(\cos \left(\frac{1}{2} \cdot \phi_2\right) + \frac{-1}{2} \cdot \left(\phi_1 \cdot \sin \left(\frac{1}{2} \cdot \phi_2\right)\right)\right)} \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
              5. Step-by-step derivation
                1. lower-+.f64N/A

                  \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \left(\cos \left(\frac{1}{2} \cdot \phi_2\right) + \color{blue}{\frac{-1}{2} \cdot \left(\phi_1 \cdot \sin \left(\frac{1}{2} \cdot \phi_2\right)\right)}\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                2. lower-cos.f64N/A

                  \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \left(\cos \left(\frac{1}{2} \cdot \phi_2\right) + \color{blue}{\frac{-1}{2}} \cdot \left(\phi_1 \cdot \sin \left(\frac{1}{2} \cdot \phi_2\right)\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                3. lower-*.f64N/A

                  \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \left(\cos \left(\frac{1}{2} \cdot \phi_2\right) + \frac{-1}{2} \cdot \left(\phi_1 \cdot \sin \left(\frac{1}{2} \cdot \phi_2\right)\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                4. lower-*.f64N/A

                  \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \left(\cos \left(\frac{1}{2} \cdot \phi_2\right) + \frac{-1}{2} \cdot \color{blue}{\left(\phi_1 \cdot \sin \left(\frac{1}{2} \cdot \phi_2\right)\right)}\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                5. lower-*.f64N/A

                  \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \left(\cos \left(\frac{1}{2} \cdot \phi_2\right) + \frac{-1}{2} \cdot \left(\phi_1 \cdot \color{blue}{\sin \left(\frac{1}{2} \cdot \phi_2\right)}\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                6. lower-sin.f64N/A

                  \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \left(\cos \left(\frac{1}{2} \cdot \phi_2\right) + \frac{-1}{2} \cdot \left(\phi_1 \cdot \sin \left(\frac{1}{2} \cdot \phi_2\right)\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                7. lower-*.f6486.0

                  \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \left(\cos \left(0.5 \cdot \phi_2\right) + -0.5 \cdot \left(\phi_1 \cdot \sin \left(0.5 \cdot \phi_2\right)\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
              6. Applied rewrites86.0%

                \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \color{blue}{\left(\cos \left(0.5 \cdot \phi_2\right) + -0.5 \cdot \left(\phi_1 \cdot \sin \left(0.5 \cdot \phi_2\right)\right)\right)} \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
              7. Taylor expanded in phi2 around 0

                \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, 1 \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
              8. Step-by-step derivation
                1. Applied rewrites85.1%

                  \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, 1 \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
              9. Recombined 2 regimes into one program.
              10. Add Preprocessing

              Alternative 5: 85.3% accurate, 4.3× speedup?

              \[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ \mathsf{hypot}\left(\phi_1 - \phi_2, 1 \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \end{array} \]
              NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
              (FPCore (R lambda1 lambda2 phi1 phi2)
               :precision binary64
               (* (hypot (- phi1 phi2) (* 1.0 (- lambda1 lambda2))) R))
              assert(R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2);
              double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
              	return hypot((phi1 - phi2), (1.0 * (lambda1 - lambda2))) * R;
              }
              
              assert R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2;
              public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
              	return Math.hypot((phi1 - phi2), (1.0 * (lambda1 - lambda2))) * R;
              }
              
              [R, lambda1, lambda2, phi1, phi2] = sort([R, lambda1, lambda2, phi1, phi2])
              def code(R, lambda1, lambda2, phi1, phi2):
              	return math.hypot((phi1 - phi2), (1.0 * (lambda1 - lambda2))) * R
              
              R, lambda1, lambda2, phi1, phi2 = sort([R, lambda1, lambda2, phi1, phi2])
              function code(R, lambda1, lambda2, phi1, phi2)
              	return Float64(hypot(Float64(phi1 - phi2), Float64(1.0 * Float64(lambda1 - lambda2))) * R)
              end
              
              R, lambda1, lambda2, phi1, phi2 = num2cell(sort([R, lambda1, lambda2, phi1, phi2])){:}
              function tmp = code(R, lambda1, lambda2, phi1, phi2)
              	tmp = hypot((phi1 - phi2), (1.0 * (lambda1 - lambda2))) * R;
              end
              
              NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
              code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(N[Sqrt[N[(phi1 - phi2), $MachinePrecision] ^ 2 + N[(1.0 * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision] * R), $MachinePrecision]
              
              \begin{array}{l}
              [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\
              \\
              \mathsf{hypot}\left(\phi_1 - \phi_2, 1 \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R
              \end{array}
              
              Derivation
              1. Initial program 59.3%

                \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
              2. Step-by-step derivation
                1. lift-*.f64N/A

                  \[\leadsto \color{blue}{R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
                2. lift-sqrt.f64N/A

                  \[\leadsto R \cdot \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
                3. lift-+.f64N/A

                  \[\leadsto R \cdot \sqrt{\color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
              3. Applied rewrites95.9%

                \[\leadsto \color{blue}{\mathsf{hypot}\left(\phi_1 - \phi_2, \cos \left(0.5 \cdot \left(\phi_2 + \phi_1\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R} \]
              4. Taylor expanded in phi1 around 0

                \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \color{blue}{\left(\cos \left(\frac{1}{2} \cdot \phi_2\right) + \frac{-1}{2} \cdot \left(\phi_1 \cdot \sin \left(\frac{1}{2} \cdot \phi_2\right)\right)\right)} \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
              5. Step-by-step derivation
                1. lower-+.f64N/A

                  \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \left(\cos \left(\frac{1}{2} \cdot \phi_2\right) + \color{blue}{\frac{-1}{2} \cdot \left(\phi_1 \cdot \sin \left(\frac{1}{2} \cdot \phi_2\right)\right)}\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                2. lower-cos.f64N/A

                  \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \left(\cos \left(\frac{1}{2} \cdot \phi_2\right) + \color{blue}{\frac{-1}{2}} \cdot \left(\phi_1 \cdot \sin \left(\frac{1}{2} \cdot \phi_2\right)\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                3. lower-*.f64N/A

                  \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \left(\cos \left(\frac{1}{2} \cdot \phi_2\right) + \frac{-1}{2} \cdot \left(\phi_1 \cdot \sin \left(\frac{1}{2} \cdot \phi_2\right)\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                4. lower-*.f64N/A

                  \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \left(\cos \left(\frac{1}{2} \cdot \phi_2\right) + \frac{-1}{2} \cdot \color{blue}{\left(\phi_1 \cdot \sin \left(\frac{1}{2} \cdot \phi_2\right)\right)}\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                5. lower-*.f64N/A

                  \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \left(\cos \left(\frac{1}{2} \cdot \phi_2\right) + \frac{-1}{2} \cdot \left(\phi_1 \cdot \color{blue}{\sin \left(\frac{1}{2} \cdot \phi_2\right)}\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                6. lower-sin.f64N/A

                  \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \left(\cos \left(\frac{1}{2} \cdot \phi_2\right) + \frac{-1}{2} \cdot \left(\phi_1 \cdot \sin \left(\frac{1}{2} \cdot \phi_2\right)\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                7. lower-*.f6482.9

                  \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \left(\cos \left(0.5 \cdot \phi_2\right) + -0.5 \cdot \left(\phi_1 \cdot \sin \left(0.5 \cdot \phi_2\right)\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
              6. Applied rewrites82.9%

                \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, \color{blue}{\left(\cos \left(0.5 \cdot \phi_2\right) + -0.5 \cdot \left(\phi_1 \cdot \sin \left(0.5 \cdot \phi_2\right)\right)\right)} \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
              7. Taylor expanded in phi2 around 0

                \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, 1 \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
              8. Step-by-step derivation
                1. Applied rewrites85.3%

                  \[\leadsto \mathsf{hypot}\left(\phi_1 - \phi_2, 1 \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                2. Add Preprocessing

                Alternative 6: 59.3% accurate, 4.5× speedup?

                \[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ \begin{array}{l} \mathbf{if}\;\lambda_1 - \lambda_2 \leq -9 \cdot 10^{+205}:\\ \;\;\;\;\left(-\phi_1\right) \cdot \left(\phi_2 \cdot \left(\frac{R}{\phi_2} - \frac{R}{\phi_1}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;R \cdot \left(\phi_2 + -1 \cdot \phi_1\right)\\ \end{array} \end{array} \]
                NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
                (FPCore (R lambda1 lambda2 phi1 phi2)
                 :precision binary64
                 (if (<= (- lambda1 lambda2) -9e+205)
                   (* (- phi1) (* phi2 (- (/ R phi2) (/ R phi1))))
                   (* R (+ phi2 (* -1.0 phi1)))))
                assert(R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2);
                double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                	double tmp;
                	if ((lambda1 - lambda2) <= -9e+205) {
                		tmp = -phi1 * (phi2 * ((R / phi2) - (R / phi1)));
                	} else {
                		tmp = R * (phi2 + (-1.0 * phi1));
                	}
                	return tmp;
                }
                
                NOTE: R, lambda1, lambda2, phi1, and phi2 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(r, lambda1, lambda2, phi1, phi2)
                use fmin_fmax_functions
                    real(8), intent (in) :: r
                    real(8), intent (in) :: lambda1
                    real(8), intent (in) :: lambda2
                    real(8), intent (in) :: phi1
                    real(8), intent (in) :: phi2
                    real(8) :: tmp
                    if ((lambda1 - lambda2) <= (-9d+205)) then
                        tmp = -phi1 * (phi2 * ((r / phi2) - (r / phi1)))
                    else
                        tmp = r * (phi2 + ((-1.0d0) * phi1))
                    end if
                    code = tmp
                end function
                
                assert R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2;
                public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                	double tmp;
                	if ((lambda1 - lambda2) <= -9e+205) {
                		tmp = -phi1 * (phi2 * ((R / phi2) - (R / phi1)));
                	} else {
                		tmp = R * (phi2 + (-1.0 * phi1));
                	}
                	return tmp;
                }
                
                [R, lambda1, lambda2, phi1, phi2] = sort([R, lambda1, lambda2, phi1, phi2])
                def code(R, lambda1, lambda2, phi1, phi2):
                	tmp = 0
                	if (lambda1 - lambda2) <= -9e+205:
                		tmp = -phi1 * (phi2 * ((R / phi2) - (R / phi1)))
                	else:
                		tmp = R * (phi2 + (-1.0 * phi1))
                	return tmp
                
                R, lambda1, lambda2, phi1, phi2 = sort([R, lambda1, lambda2, phi1, phi2])
                function code(R, lambda1, lambda2, phi1, phi2)
                	tmp = 0.0
                	if (Float64(lambda1 - lambda2) <= -9e+205)
                		tmp = Float64(Float64(-phi1) * Float64(phi2 * Float64(Float64(R / phi2) - Float64(R / phi1))));
                	else
                		tmp = Float64(R * Float64(phi2 + Float64(-1.0 * phi1)));
                	end
                	return tmp
                end
                
                R, lambda1, lambda2, phi1, phi2 = num2cell(sort([R, lambda1, lambda2, phi1, phi2])){:}
                function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
                	tmp = 0.0;
                	if ((lambda1 - lambda2) <= -9e+205)
                		tmp = -phi1 * (phi2 * ((R / phi2) - (R / phi1)));
                	else
                		tmp = R * (phi2 + (-1.0 * phi1));
                	end
                	tmp_2 = tmp;
                end
                
                NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
                code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[LessEqual[N[(lambda1 - lambda2), $MachinePrecision], -9e+205], N[((-phi1) * N[(phi2 * N[(N[(R / phi2), $MachinePrecision] - N[(R / phi1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(R * N[(phi2 + N[(-1.0 * phi1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
                
                \begin{array}{l}
                [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\
                \\
                \begin{array}{l}
                \mathbf{if}\;\lambda_1 - \lambda_2 \leq -9 \cdot 10^{+205}:\\
                \;\;\;\;\left(-\phi_1\right) \cdot \left(\phi_2 \cdot \left(\frac{R}{\phi_2} - \frac{R}{\phi_1}\right)\right)\\
                
                \mathbf{else}:\\
                \;\;\;\;R \cdot \left(\phi_2 + -1 \cdot \phi_1\right)\\
                
                
                \end{array}
                \end{array}
                
                Derivation
                1. Split input into 2 regimes
                2. if (-.f64 lambda1 lambda2) < -9.00000000000000071e205

                  1. Initial program 45.0%

                    \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
                  2. Taylor expanded in phi1 around -inf

                    \[\leadsto \color{blue}{-1 \cdot \left(\phi_1 \cdot \left(R + -1 \cdot \frac{R \cdot \phi_2}{\phi_1}\right)\right)} \]
                  3. Step-by-step derivation
                    1. associate-*r*N/A

                      \[\leadsto \left(-1 \cdot \phi_1\right) \cdot \color{blue}{\left(R + -1 \cdot \frac{R \cdot \phi_2}{\phi_1}\right)} \]
                    2. mul-1-negN/A

                      \[\leadsto \left(\mathsf{neg}\left(\phi_1\right)\right) \cdot \left(\color{blue}{R} + -1 \cdot \frac{R \cdot \phi_2}{\phi_1}\right) \]
                    3. lower-*.f64N/A

                      \[\leadsto \left(\mathsf{neg}\left(\phi_1\right)\right) \cdot \color{blue}{\left(R + -1 \cdot \frac{R \cdot \phi_2}{\phi_1}\right)} \]
                    4. lower-neg.f64N/A

                      \[\leadsto \left(-\phi_1\right) \cdot \left(\color{blue}{R} + -1 \cdot \frac{R \cdot \phi_2}{\phi_1}\right) \]
                    5. +-commutativeN/A

                      \[\leadsto \left(-\phi_1\right) \cdot \left(-1 \cdot \frac{R \cdot \phi_2}{\phi_1} + \color{blue}{R}\right) \]
                    6. lower-+.f64N/A

                      \[\leadsto \left(-\phi_1\right) \cdot \left(-1 \cdot \frac{R \cdot \phi_2}{\phi_1} + \color{blue}{R}\right) \]
                    7. mul-1-negN/A

                      \[\leadsto \left(-\phi_1\right) \cdot \left(\left(\mathsf{neg}\left(\frac{R \cdot \phi_2}{\phi_1}\right)\right) + R\right) \]
                    8. lower-neg.f64N/A

                      \[\leadsto \left(-\phi_1\right) \cdot \left(\left(-\frac{R \cdot \phi_2}{\phi_1}\right) + R\right) \]
                    9. lower-/.f64N/A

                      \[\leadsto \left(-\phi_1\right) \cdot \left(\left(-\frac{R \cdot \phi_2}{\phi_1}\right) + R\right) \]
                    10. *-commutativeN/A

                      \[\leadsto \left(-\phi_1\right) \cdot \left(\left(-\frac{\phi_2 \cdot R}{\phi_1}\right) + R\right) \]
                    11. lower-*.f6434.3

                      \[\leadsto \left(-\phi_1\right) \cdot \left(\left(-\frac{\phi_2 \cdot R}{\phi_1}\right) + R\right) \]
                  4. Applied rewrites34.3%

                    \[\leadsto \color{blue}{\left(-\phi_1\right) \cdot \left(\left(-\frac{\phi_2 \cdot R}{\phi_1}\right) + R\right)} \]
                  5. Taylor expanded in phi2 around inf

                    \[\leadsto \left(-\phi_1\right) \cdot \left(\phi_2 \cdot \color{blue}{\left(\frac{R}{\phi_2} - \frac{R}{\phi_1}\right)}\right) \]
                  6. Step-by-step derivation
                    1. lower-*.f64N/A

                      \[\leadsto \left(-\phi_1\right) \cdot \left(\phi_2 \cdot \left(\frac{R}{\phi_2} - \color{blue}{\frac{R}{\phi_1}}\right)\right) \]
                    2. lower--.f64N/A

                      \[\leadsto \left(-\phi_1\right) \cdot \left(\phi_2 \cdot \left(\frac{R}{\phi_2} - \frac{R}{\color{blue}{\phi_1}}\right)\right) \]
                    3. lower-/.f64N/A

                      \[\leadsto \left(-\phi_1\right) \cdot \left(\phi_2 \cdot \left(\frac{R}{\phi_2} - \frac{R}{\phi_1}\right)\right) \]
                    4. lower-/.f6439.2

                      \[\leadsto \left(-\phi_1\right) \cdot \left(\phi_2 \cdot \left(\frac{R}{\phi_2} - \frac{R}{\phi_1}\right)\right) \]
                  7. Applied rewrites39.2%

                    \[\leadsto \left(-\phi_1\right) \cdot \left(\phi_2 \cdot \color{blue}{\left(\frac{R}{\phi_2} - \frac{R}{\phi_1}\right)}\right) \]

                  if -9.00000000000000071e205 < (-.f64 lambda1 lambda2)

                  1. Initial program 62.0%

                    \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
                  2. Taylor expanded in phi2 around inf

                    \[\leadsto R \cdot \color{blue}{\left(\phi_2 \cdot \left(1 + -1 \cdot \frac{\phi_1}{\phi_2}\right)\right)} \]
                  3. Step-by-step derivation
                    1. *-commutativeN/A

                      \[\leadsto R \cdot \left(\left(1 + -1 \cdot \frac{\phi_1}{\phi_2}\right) \cdot \color{blue}{\phi_2}\right) \]
                    2. lower-*.f64N/A

                      \[\leadsto R \cdot \left(\left(1 + -1 \cdot \frac{\phi_1}{\phi_2}\right) \cdot \color{blue}{\phi_2}\right) \]
                    3. +-commutativeN/A

                      \[\leadsto R \cdot \left(\left(-1 \cdot \frac{\phi_1}{\phi_2} + 1\right) \cdot \phi_2\right) \]
                    4. lower-+.f64N/A

                      \[\leadsto R \cdot \left(\left(-1 \cdot \frac{\phi_1}{\phi_2} + 1\right) \cdot \phi_2\right) \]
                    5. associate-*r/N/A

                      \[\leadsto R \cdot \left(\left(\frac{-1 \cdot \phi_1}{\phi_2} + 1\right) \cdot \phi_2\right) \]
                    6. mul-1-negN/A

                      \[\leadsto R \cdot \left(\left(\frac{\mathsf{neg}\left(\phi_1\right)}{\phi_2} + 1\right) \cdot \phi_2\right) \]
                    7. lower-/.f64N/A

                      \[\leadsto R \cdot \left(\left(\frac{\mathsf{neg}\left(\phi_1\right)}{\phi_2} + 1\right) \cdot \phi_2\right) \]
                    8. lower-neg.f6457.0

                      \[\leadsto R \cdot \left(\left(\frac{-\phi_1}{\phi_2} + 1\right) \cdot \phi_2\right) \]
                  4. Applied rewrites57.0%

                    \[\leadsto R \cdot \color{blue}{\left(\left(\frac{-\phi_1}{\phi_2} + 1\right) \cdot \phi_2\right)} \]
                  5. Taylor expanded in phi1 around 0

                    \[\leadsto R \cdot \left(\phi_2 + \color{blue}{-1 \cdot \phi_1}\right) \]
                  6. Step-by-step derivation
                    1. lower-+.f64N/A

                      \[\leadsto R \cdot \left(\phi_2 + -1 \cdot \color{blue}{\phi_1}\right) \]
                    2. lower-*.f6462.9

                      \[\leadsto R \cdot \left(\phi_2 + -1 \cdot \phi_1\right) \]
                  7. Applied rewrites62.9%

                    \[\leadsto R \cdot \left(\phi_2 + \color{blue}{-1 \cdot \phi_1}\right) \]
                3. Recombined 2 regimes into one program.
                4. Add Preprocessing

                Alternative 7: 58.5% accurate, 5.3× speedup?

                \[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ \begin{array}{l} \mathbf{if}\;\lambda_1 - \lambda_2 \leq -5.2 \cdot 10^{+255}:\\ \;\;\;\;\left(-\phi_1\right) \cdot \left(R \cdot \left(1 - \frac{\phi_2}{\phi_1}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;R \cdot \left(\phi_2 + -1 \cdot \phi_1\right)\\ \end{array} \end{array} \]
                NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
                (FPCore (R lambda1 lambda2 phi1 phi2)
                 :precision binary64
                 (if (<= (- lambda1 lambda2) -5.2e+255)
                   (* (- phi1) (* R (- 1.0 (/ phi2 phi1))))
                   (* R (+ phi2 (* -1.0 phi1)))))
                assert(R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2);
                double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                	double tmp;
                	if ((lambda1 - lambda2) <= -5.2e+255) {
                		tmp = -phi1 * (R * (1.0 - (phi2 / phi1)));
                	} else {
                		tmp = R * (phi2 + (-1.0 * phi1));
                	}
                	return tmp;
                }
                
                NOTE: R, lambda1, lambda2, phi1, and phi2 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(r, lambda1, lambda2, phi1, phi2)
                use fmin_fmax_functions
                    real(8), intent (in) :: r
                    real(8), intent (in) :: lambda1
                    real(8), intent (in) :: lambda2
                    real(8), intent (in) :: phi1
                    real(8), intent (in) :: phi2
                    real(8) :: tmp
                    if ((lambda1 - lambda2) <= (-5.2d+255)) then
                        tmp = -phi1 * (r * (1.0d0 - (phi2 / phi1)))
                    else
                        tmp = r * (phi2 + ((-1.0d0) * phi1))
                    end if
                    code = tmp
                end function
                
                assert R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2;
                public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                	double tmp;
                	if ((lambda1 - lambda2) <= -5.2e+255) {
                		tmp = -phi1 * (R * (1.0 - (phi2 / phi1)));
                	} else {
                		tmp = R * (phi2 + (-1.0 * phi1));
                	}
                	return tmp;
                }
                
                [R, lambda1, lambda2, phi1, phi2] = sort([R, lambda1, lambda2, phi1, phi2])
                def code(R, lambda1, lambda2, phi1, phi2):
                	tmp = 0
                	if (lambda1 - lambda2) <= -5.2e+255:
                		tmp = -phi1 * (R * (1.0 - (phi2 / phi1)))
                	else:
                		tmp = R * (phi2 + (-1.0 * phi1))
                	return tmp
                
                R, lambda1, lambda2, phi1, phi2 = sort([R, lambda1, lambda2, phi1, phi2])
                function code(R, lambda1, lambda2, phi1, phi2)
                	tmp = 0.0
                	if (Float64(lambda1 - lambda2) <= -5.2e+255)
                		tmp = Float64(Float64(-phi1) * Float64(R * Float64(1.0 - Float64(phi2 / phi1))));
                	else
                		tmp = Float64(R * Float64(phi2 + Float64(-1.0 * phi1)));
                	end
                	return tmp
                end
                
                R, lambda1, lambda2, phi1, phi2 = num2cell(sort([R, lambda1, lambda2, phi1, phi2])){:}
                function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
                	tmp = 0.0;
                	if ((lambda1 - lambda2) <= -5.2e+255)
                		tmp = -phi1 * (R * (1.0 - (phi2 / phi1)));
                	else
                		tmp = R * (phi2 + (-1.0 * phi1));
                	end
                	tmp_2 = tmp;
                end
                
                NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
                code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[LessEqual[N[(lambda1 - lambda2), $MachinePrecision], -5.2e+255], N[((-phi1) * N[(R * N[(1.0 - N[(phi2 / phi1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(R * N[(phi2 + N[(-1.0 * phi1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
                
                \begin{array}{l}
                [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\
                \\
                \begin{array}{l}
                \mathbf{if}\;\lambda_1 - \lambda_2 \leq -5.2 \cdot 10^{+255}:\\
                \;\;\;\;\left(-\phi_1\right) \cdot \left(R \cdot \left(1 - \frac{\phi_2}{\phi_1}\right)\right)\\
                
                \mathbf{else}:\\
                \;\;\;\;R \cdot \left(\phi_2 + -1 \cdot \phi_1\right)\\
                
                
                \end{array}
                \end{array}
                
                Derivation
                1. Split input into 2 regimes
                2. if (-.f64 lambda1 lambda2) < -5.20000000000000019e255

                  1. Initial program 47.6%

                    \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
                  2. Taylor expanded in phi1 around -inf

                    \[\leadsto \color{blue}{-1 \cdot \left(\phi_1 \cdot \left(R + -1 \cdot \frac{R \cdot \phi_2}{\phi_1}\right)\right)} \]
                  3. Step-by-step derivation
                    1. associate-*r*N/A

                      \[\leadsto \left(-1 \cdot \phi_1\right) \cdot \color{blue}{\left(R + -1 \cdot \frac{R \cdot \phi_2}{\phi_1}\right)} \]
                    2. mul-1-negN/A

                      \[\leadsto \left(\mathsf{neg}\left(\phi_1\right)\right) \cdot \left(\color{blue}{R} + -1 \cdot \frac{R \cdot \phi_2}{\phi_1}\right) \]
                    3. lower-*.f64N/A

                      \[\leadsto \left(\mathsf{neg}\left(\phi_1\right)\right) \cdot \color{blue}{\left(R + -1 \cdot \frac{R \cdot \phi_2}{\phi_1}\right)} \]
                    4. lower-neg.f64N/A

                      \[\leadsto \left(-\phi_1\right) \cdot \left(\color{blue}{R} + -1 \cdot \frac{R \cdot \phi_2}{\phi_1}\right) \]
                    5. +-commutativeN/A

                      \[\leadsto \left(-\phi_1\right) \cdot \left(-1 \cdot \frac{R \cdot \phi_2}{\phi_1} + \color{blue}{R}\right) \]
                    6. lower-+.f64N/A

                      \[\leadsto \left(-\phi_1\right) \cdot \left(-1 \cdot \frac{R \cdot \phi_2}{\phi_1} + \color{blue}{R}\right) \]
                    7. mul-1-negN/A

                      \[\leadsto \left(-\phi_1\right) \cdot \left(\left(\mathsf{neg}\left(\frac{R \cdot \phi_2}{\phi_1}\right)\right) + R\right) \]
                    8. lower-neg.f64N/A

                      \[\leadsto \left(-\phi_1\right) \cdot \left(\left(-\frac{R \cdot \phi_2}{\phi_1}\right) + R\right) \]
                    9. lower-/.f64N/A

                      \[\leadsto \left(-\phi_1\right) \cdot \left(\left(-\frac{R \cdot \phi_2}{\phi_1}\right) + R\right) \]
                    10. *-commutativeN/A

                      \[\leadsto \left(-\phi_1\right) \cdot \left(\left(-\frac{\phi_2 \cdot R}{\phi_1}\right) + R\right) \]
                    11. lower-*.f6432.9

                      \[\leadsto \left(-\phi_1\right) \cdot \left(\left(-\frac{\phi_2 \cdot R}{\phi_1}\right) + R\right) \]
                  4. Applied rewrites32.9%

                    \[\leadsto \color{blue}{\left(-\phi_1\right) \cdot \left(\left(-\frac{\phi_2 \cdot R}{\phi_1}\right) + R\right)} \]
                  5. Taylor expanded in R around 0

                    \[\leadsto \left(-\phi_1\right) \cdot \left(R \cdot \color{blue}{\left(1 - \frac{\phi_2}{\phi_1}\right)}\right) \]
                  6. Step-by-step derivation
                    1. lower-*.f64N/A

                      \[\leadsto \left(-\phi_1\right) \cdot \left(R \cdot \left(1 - \color{blue}{\frac{\phi_2}{\phi_1}}\right)\right) \]
                    2. lower--.f64N/A

                      \[\leadsto \left(-\phi_1\right) \cdot \left(R \cdot \left(1 - \frac{\phi_2}{\color{blue}{\phi_1}}\right)\right) \]
                    3. lower-/.f6433.8

                      \[\leadsto \left(-\phi_1\right) \cdot \left(R \cdot \left(1 - \frac{\phi_2}{\phi_1}\right)\right) \]
                  7. Applied rewrites33.8%

                    \[\leadsto \left(-\phi_1\right) \cdot \left(R \cdot \color{blue}{\left(1 - \frac{\phi_2}{\phi_1}\right)}\right) \]

                  if -5.20000000000000019e255 < (-.f64 lambda1 lambda2)

                  1. Initial program 60.4%

                    \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
                  2. Taylor expanded in phi2 around inf

                    \[\leadsto R \cdot \color{blue}{\left(\phi_2 \cdot \left(1 + -1 \cdot \frac{\phi_1}{\phi_2}\right)\right)} \]
                  3. Step-by-step derivation
                    1. *-commutativeN/A

                      \[\leadsto R \cdot \left(\left(1 + -1 \cdot \frac{\phi_1}{\phi_2}\right) \cdot \color{blue}{\phi_2}\right) \]
                    2. lower-*.f64N/A

                      \[\leadsto R \cdot \left(\left(1 + -1 \cdot \frac{\phi_1}{\phi_2}\right) \cdot \color{blue}{\phi_2}\right) \]
                    3. +-commutativeN/A

                      \[\leadsto R \cdot \left(\left(-1 \cdot \frac{\phi_1}{\phi_2} + 1\right) \cdot \phi_2\right) \]
                    4. lower-+.f64N/A

                      \[\leadsto R \cdot \left(\left(-1 \cdot \frac{\phi_1}{\phi_2} + 1\right) \cdot \phi_2\right) \]
                    5. associate-*r/N/A

                      \[\leadsto R \cdot \left(\left(\frac{-1 \cdot \phi_1}{\phi_2} + 1\right) \cdot \phi_2\right) \]
                    6. mul-1-negN/A

                      \[\leadsto R \cdot \left(\left(\frac{\mathsf{neg}\left(\phi_1\right)}{\phi_2} + 1\right) \cdot \phi_2\right) \]
                    7. lower-/.f64N/A

                      \[\leadsto R \cdot \left(\left(\frac{\mathsf{neg}\left(\phi_1\right)}{\phi_2} + 1\right) \cdot \phi_2\right) \]
                    8. lower-neg.f6455.1

                      \[\leadsto R \cdot \left(\left(\frac{-\phi_1}{\phi_2} + 1\right) \cdot \phi_2\right) \]
                  4. Applied rewrites55.1%

                    \[\leadsto R \cdot \color{blue}{\left(\left(\frac{-\phi_1}{\phi_2} + 1\right) \cdot \phi_2\right)} \]
                  5. Taylor expanded in phi1 around 0

                    \[\leadsto R \cdot \left(\phi_2 + \color{blue}{-1 \cdot \phi_1}\right) \]
                  6. Step-by-step derivation
                    1. lower-+.f64N/A

                      \[\leadsto R \cdot \left(\phi_2 + -1 \cdot \color{blue}{\phi_1}\right) \]
                    2. lower-*.f6460.7

                      \[\leadsto R \cdot \left(\phi_2 + -1 \cdot \phi_1\right) \]
                  7. Applied rewrites60.7%

                    \[\leadsto R \cdot \left(\phi_2 + \color{blue}{-1 \cdot \phi_1}\right) \]
                3. Recombined 2 regimes into one program.
                4. Add Preprocessing

                Alternative 8: 58.1% accurate, 11.1× speedup?

                \[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ R \cdot \left(\phi_2 + -1 \cdot \phi_1\right) \end{array} \]
                NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
                (FPCore (R lambda1 lambda2 phi1 phi2)
                 :precision binary64
                 (* R (+ phi2 (* -1.0 phi1))))
                assert(R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2);
                double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                	return R * (phi2 + (-1.0 * phi1));
                }
                
                NOTE: R, lambda1, lambda2, phi1, and phi2 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(r, lambda1, lambda2, phi1, phi2)
                use fmin_fmax_functions
                    real(8), intent (in) :: r
                    real(8), intent (in) :: lambda1
                    real(8), intent (in) :: lambda2
                    real(8), intent (in) :: phi1
                    real(8), intent (in) :: phi2
                    code = r * (phi2 + ((-1.0d0) * phi1))
                end function
                
                assert R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2;
                public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                	return R * (phi2 + (-1.0 * phi1));
                }
                
                [R, lambda1, lambda2, phi1, phi2] = sort([R, lambda1, lambda2, phi1, phi2])
                def code(R, lambda1, lambda2, phi1, phi2):
                	return R * (phi2 + (-1.0 * phi1))
                
                R, lambda1, lambda2, phi1, phi2 = sort([R, lambda1, lambda2, phi1, phi2])
                function code(R, lambda1, lambda2, phi1, phi2)
                	return Float64(R * Float64(phi2 + Float64(-1.0 * phi1)))
                end
                
                R, lambda1, lambda2, phi1, phi2 = num2cell(sort([R, lambda1, lambda2, phi1, phi2])){:}
                function tmp = code(R, lambda1, lambda2, phi1, phi2)
                	tmp = R * (phi2 + (-1.0 * phi1));
                end
                
                NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
                code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(R * N[(phi2 + N[(-1.0 * phi1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
                
                \begin{array}{l}
                [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\
                \\
                R \cdot \left(\phi_2 + -1 \cdot \phi_1\right)
                \end{array}
                
                Derivation
                1. Initial program 59.3%

                  \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
                2. Taylor expanded in phi2 around inf

                  \[\leadsto R \cdot \color{blue}{\left(\phi_2 \cdot \left(1 + -1 \cdot \frac{\phi_1}{\phi_2}\right)\right)} \]
                3. Step-by-step derivation
                  1. *-commutativeN/A

                    \[\leadsto R \cdot \left(\left(1 + -1 \cdot \frac{\phi_1}{\phi_2}\right) \cdot \color{blue}{\phi_2}\right) \]
                  2. lower-*.f64N/A

                    \[\leadsto R \cdot \left(\left(1 + -1 \cdot \frac{\phi_1}{\phi_2}\right) \cdot \color{blue}{\phi_2}\right) \]
                  3. +-commutativeN/A

                    \[\leadsto R \cdot \left(\left(-1 \cdot \frac{\phi_1}{\phi_2} + 1\right) \cdot \phi_2\right) \]
                  4. lower-+.f64N/A

                    \[\leadsto R \cdot \left(\left(-1 \cdot \frac{\phi_1}{\phi_2} + 1\right) \cdot \phi_2\right) \]
                  5. associate-*r/N/A

                    \[\leadsto R \cdot \left(\left(\frac{-1 \cdot \phi_1}{\phi_2} + 1\right) \cdot \phi_2\right) \]
                  6. mul-1-negN/A

                    \[\leadsto R \cdot \left(\left(\frac{\mathsf{neg}\left(\phi_1\right)}{\phi_2} + 1\right) \cdot \phi_2\right) \]
                  7. lower-/.f64N/A

                    \[\leadsto R \cdot \left(\left(\frac{\mathsf{neg}\left(\phi_1\right)}{\phi_2} + 1\right) \cdot \phi_2\right) \]
                  8. lower-neg.f6453.0

                    \[\leadsto R \cdot \left(\left(\frac{-\phi_1}{\phi_2} + 1\right) \cdot \phi_2\right) \]
                4. Applied rewrites53.0%

                  \[\leadsto R \cdot \color{blue}{\left(\left(\frac{-\phi_1}{\phi_2} + 1\right) \cdot \phi_2\right)} \]
                5. Taylor expanded in phi1 around 0

                  \[\leadsto R \cdot \left(\phi_2 + \color{blue}{-1 \cdot \phi_1}\right) \]
                6. Step-by-step derivation
                  1. lower-+.f64N/A

                    \[\leadsto R \cdot \left(\phi_2 + -1 \cdot \color{blue}{\phi_1}\right) \]
                  2. lower-*.f6458.1

                    \[\leadsto R \cdot \left(\phi_2 + -1 \cdot \phi_1\right) \]
                7. Applied rewrites58.1%

                  \[\leadsto R \cdot \left(\phi_2 + \color{blue}{-1 \cdot \phi_1}\right) \]
                8. Add Preprocessing

                Alternative 9: 52.5% accurate, 12.2× speedup?

                \[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ \begin{array}{l} \mathbf{if}\;\phi_1 \leq -0.115:\\ \;\;\;\;R \cdot \left(-\phi_1\right)\\ \mathbf{else}:\\ \;\;\;\;R \cdot \phi_2\\ \end{array} \end{array} \]
                NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
                (FPCore (R lambda1 lambda2 phi1 phi2)
                 :precision binary64
                 (if (<= phi1 -0.115) (* R (- phi1)) (* R phi2)))
                assert(R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2);
                double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                	double tmp;
                	if (phi1 <= -0.115) {
                		tmp = R * -phi1;
                	} else {
                		tmp = R * phi2;
                	}
                	return tmp;
                }
                
                NOTE: R, lambda1, lambda2, phi1, and phi2 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(r, lambda1, lambda2, phi1, phi2)
                use fmin_fmax_functions
                    real(8), intent (in) :: r
                    real(8), intent (in) :: lambda1
                    real(8), intent (in) :: lambda2
                    real(8), intent (in) :: phi1
                    real(8), intent (in) :: phi2
                    real(8) :: tmp
                    if (phi1 <= (-0.115d0)) then
                        tmp = r * -phi1
                    else
                        tmp = r * phi2
                    end if
                    code = tmp
                end function
                
                assert R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2;
                public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                	double tmp;
                	if (phi1 <= -0.115) {
                		tmp = R * -phi1;
                	} else {
                		tmp = R * phi2;
                	}
                	return tmp;
                }
                
                [R, lambda1, lambda2, phi1, phi2] = sort([R, lambda1, lambda2, phi1, phi2])
                def code(R, lambda1, lambda2, phi1, phi2):
                	tmp = 0
                	if phi1 <= -0.115:
                		tmp = R * -phi1
                	else:
                		tmp = R * phi2
                	return tmp
                
                R, lambda1, lambda2, phi1, phi2 = sort([R, lambda1, lambda2, phi1, phi2])
                function code(R, lambda1, lambda2, phi1, phi2)
                	tmp = 0.0
                	if (phi1 <= -0.115)
                		tmp = Float64(R * Float64(-phi1));
                	else
                		tmp = Float64(R * phi2);
                	end
                	return tmp
                end
                
                R, lambda1, lambda2, phi1, phi2 = num2cell(sort([R, lambda1, lambda2, phi1, phi2])){:}
                function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
                	tmp = 0.0;
                	if (phi1 <= -0.115)
                		tmp = R * -phi1;
                	else
                		tmp = R * phi2;
                	end
                	tmp_2 = tmp;
                end
                
                NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
                code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[LessEqual[phi1, -0.115], N[(R * (-phi1)), $MachinePrecision], N[(R * phi2), $MachinePrecision]]
                
                \begin{array}{l}
                [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\
                \\
                \begin{array}{l}
                \mathbf{if}\;\phi_1 \leq -0.115:\\
                \;\;\;\;R \cdot \left(-\phi_1\right)\\
                
                \mathbf{else}:\\
                \;\;\;\;R \cdot \phi_2\\
                
                
                \end{array}
                \end{array}
                
                Derivation
                1. Split input into 2 regimes
                2. if phi1 < -0.115000000000000005

                  1. Initial program 53.0%

                    \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
                  2. Taylor expanded in phi1 around -inf

                    \[\leadsto R \cdot \color{blue}{\left(-1 \cdot \phi_1\right)} \]
                  3. Step-by-step derivation
                    1. mul-1-negN/A

                      \[\leadsto R \cdot \left(\mathsf{neg}\left(\phi_1\right)\right) \]
                    2. lower-neg.f6464.3

                      \[\leadsto R \cdot \left(-\phi_1\right) \]
                  4. Applied rewrites64.3%

                    \[\leadsto R \cdot \color{blue}{\left(-\phi_1\right)} \]

                  if -0.115000000000000005 < phi1

                  1. Initial program 64.3%

                    \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
                  2. Taylor expanded in phi2 around inf

                    \[\leadsto R \cdot \color{blue}{\phi_2} \]
                  3. Step-by-step derivation
                    1. Applied rewrites43.4%

                      \[\leadsto R \cdot \color{blue}{\phi_2} \]
                  4. Recombined 2 regimes into one program.
                  5. Add Preprocessing

                  Alternative 10: 31.5% accurate, 27.0× speedup?

                  \[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ R \cdot \phi_2 \end{array} \]
                  NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
                  (FPCore (R lambda1 lambda2 phi1 phi2) :precision binary64 (* R phi2))
                  assert(R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2);
                  double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                  	return R * phi2;
                  }
                  
                  NOTE: R, lambda1, lambda2, phi1, and phi2 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(r, lambda1, lambda2, phi1, phi2)
                  use fmin_fmax_functions
                      real(8), intent (in) :: r
                      real(8), intent (in) :: lambda1
                      real(8), intent (in) :: lambda2
                      real(8), intent (in) :: phi1
                      real(8), intent (in) :: phi2
                      code = r * phi2
                  end function
                  
                  assert R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2;
                  public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                  	return R * phi2;
                  }
                  
                  [R, lambda1, lambda2, phi1, phi2] = sort([R, lambda1, lambda2, phi1, phi2])
                  def code(R, lambda1, lambda2, phi1, phi2):
                  	return R * phi2
                  
                  R, lambda1, lambda2, phi1, phi2 = sort([R, lambda1, lambda2, phi1, phi2])
                  function code(R, lambda1, lambda2, phi1, phi2)
                  	return Float64(R * phi2)
                  end
                  
                  R, lambda1, lambda2, phi1, phi2 = num2cell(sort([R, lambda1, lambda2, phi1, phi2])){:}
                  function tmp = code(R, lambda1, lambda2, phi1, phi2)
                  	tmp = R * phi2;
                  end
                  
                  NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
                  code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(R * phi2), $MachinePrecision]
                  
                  \begin{array}{l}
                  [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\
                  \\
                  R \cdot \phi_2
                  \end{array}
                  
                  Derivation
                  1. Initial program 59.3%

                    \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
                  2. Taylor expanded in phi2 around inf

                    \[\leadsto R \cdot \color{blue}{\phi_2} \]
                  3. Step-by-step derivation
                    1. Applied rewrites31.5%

                      \[\leadsto R \cdot \color{blue}{\phi_2} \]
                    2. Add Preprocessing

                    Alternative 11: 3.8% accurate, 27.0× speedup?

                    \[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ R \cdot \phi_1 \end{array} \]
                    NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
                    (FPCore (R lambda1 lambda2 phi1 phi2) :precision binary64 (* R phi1))
                    assert(R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2);
                    double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                    	return R * phi1;
                    }
                    
                    NOTE: R, lambda1, lambda2, phi1, and phi2 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(r, lambda1, lambda2, phi1, phi2)
                    use fmin_fmax_functions
                        real(8), intent (in) :: r
                        real(8), intent (in) :: lambda1
                        real(8), intent (in) :: lambda2
                        real(8), intent (in) :: phi1
                        real(8), intent (in) :: phi2
                        code = r * phi1
                    end function
                    
                    assert R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2;
                    public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                    	return R * phi1;
                    }
                    
                    [R, lambda1, lambda2, phi1, phi2] = sort([R, lambda1, lambda2, phi1, phi2])
                    def code(R, lambda1, lambda2, phi1, phi2):
                    	return R * phi1
                    
                    R, lambda1, lambda2, phi1, phi2 = sort([R, lambda1, lambda2, phi1, phi2])
                    function code(R, lambda1, lambda2, phi1, phi2)
                    	return Float64(R * phi1)
                    end
                    
                    R, lambda1, lambda2, phi1, phi2 = num2cell(sort([R, lambda1, lambda2, phi1, phi2])){:}
                    function tmp = code(R, lambda1, lambda2, phi1, phi2)
                    	tmp = R * phi1;
                    end
                    
                    NOTE: R, lambda1, lambda2, phi1, and phi2 should be sorted in increasing order before calling this function.
                    code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(R * phi1), $MachinePrecision]
                    
                    \begin{array}{l}
                    [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\
                    \\
                    R \cdot \phi_1
                    \end{array}
                    
                    Derivation
                    1. Initial program 59.3%

                      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
                    2. Taylor expanded in phi1 around inf

                      \[\leadsto R \cdot \color{blue}{\phi_1} \]
                    3. Step-by-step derivation
                      1. Applied rewrites3.8%

                        \[\leadsto R \cdot \color{blue}{\phi_1} \]
                      2. Add Preprocessing

                      Reproduce

                      ?
                      herbie shell --seed 2025128 
                      (FPCore (R lambda1 lambda2 phi1 phi2)
                        :name "Equirectangular approximation to distance on a great circle"
                        :precision binary64
                        (* R (sqrt (+ (* (* (- lambda1 lambda2) (cos (/ (+ phi1 phi2) 2.0))) (* (- lambda1 lambda2) (cos (/ (+ phi1 phi2) 2.0)))) (* (- phi1 phi2) (- phi1 phi2))))))