Equirectangular approximation to distance on a great circle

Percentage Accurate: 59.1% → 95.5%
Time: 5.4s
Alternatives: 13
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 13 alternatives:

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

Initial Program: 59.1% 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: 95.5% accurate, 1.7× speedup?

\[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ \begin{array}{l} \mathbf{if}\;\phi_2 \leq 1.25 \cdot 10^{-12}:\\ \;\;\;\;R \cdot \mathsf{hypot}\left(\cos \left(0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right), \phi_1 - \phi_2\right)\\ \mathbf{else}:\\ \;\;\;\;R \cdot \mathsf{hypot}\left(\cos \left(0.5 \cdot \phi_2\right) \cdot \left(\lambda_1 - \lambda_2\right), \phi_1 - \phi_2\right)\\ \end{array} \end{array} \]
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 (<= phi2 1.25e-12)
   (* R (hypot (* (cos (* 0.5 phi1)) (- lambda1 lambda2)) (- phi1 phi2)))
   (* R (hypot (* (cos (* 0.5 phi2)) (- lambda1 lambda2)) (- phi1 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 (phi2 <= 1.25e-12) {
		tmp = R * hypot((cos((0.5 * phi1)) * (lambda1 - lambda2)), (phi1 - phi2));
	} else {
		tmp = R * hypot((cos((0.5 * phi2)) * (lambda1 - lambda2)), (phi1 - phi2));
	}
	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 <= 1.25e-12) {
		tmp = R * Math.hypot((Math.cos((0.5 * phi1)) * (lambda1 - lambda2)), (phi1 - phi2));
	} else {
		tmp = R * Math.hypot((Math.cos((0.5 * phi2)) * (lambda1 - lambda2)), (phi1 - phi2));
	}
	return tmp;
}
[R, lambda1, lambda2, phi1, phi2] = sort([R, lambda1, lambda2, phi1, phi2])
def code(R, lambda1, lambda2, phi1, phi2):
	tmp = 0
	if phi2 <= 1.25e-12:
		tmp = R * math.hypot((math.cos((0.5 * phi1)) * (lambda1 - lambda2)), (phi1 - phi2))
	else:
		tmp = R * math.hypot((math.cos((0.5 * phi2)) * (lambda1 - lambda2)), (phi1 - 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 (phi2 <= 1.25e-12)
		tmp = Float64(R * hypot(Float64(cos(Float64(0.5 * phi1)) * Float64(lambda1 - lambda2)), Float64(phi1 - phi2)));
	else
		tmp = Float64(R * hypot(Float64(cos(Float64(0.5 * phi2)) * Float64(lambda1 - lambda2)), Float64(phi1 - 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 (phi2 <= 1.25e-12)
		tmp = R * hypot((cos((0.5 * phi1)) * (lambda1 - lambda2)), (phi1 - phi2));
	else
		tmp = R * hypot((cos((0.5 * phi2)) * (lambda1 - lambda2)), (phi1 - 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[phi2, 1.25e-12], N[(R * N[Sqrt[N[(N[Cos[N[(0.5 * phi1), $MachinePrecision]], $MachinePrecision] * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision] ^ 2 + N[(phi1 - phi2), $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision], N[(R * N[Sqrt[N[(N[Cos[N[(0.5 * phi2), $MachinePrecision]], $MachinePrecision] * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision] ^ 2 + N[(phi1 - phi2), $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
[R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\
\\
\begin{array}{l}
\mathbf{if}\;\phi_2 \leq 1.25 \cdot 10^{-12}:\\
\;\;\;\;R \cdot \mathsf{hypot}\left(\cos \left(0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right), \phi_1 - \phi_2\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if phi2 < 1.24999999999999992e-12

    1. Initial program 59.1%

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

        \[\leadsto R \cdot \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
      2. 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 rewrites95.5%

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

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

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

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

        \[\leadsto R \cdot \mathsf{hypot}\left(\cos \left(\frac{1}{2} \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right), \phi_1 - \phi_2\right) \]
      4. lift--.f6490.0

        \[\leadsto R \cdot \mathsf{hypot}\left(\cos \left(0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \color{blue}{\lambda_2}\right), \phi_1 - \phi_2\right) \]
    6. Applied rewrites90.0%

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

    if 1.24999999999999992e-12 < phi2

    1. Initial program 59.1%

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

        \[\leadsto R \cdot \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
      2. 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 rewrites95.5%

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

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

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

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

        \[\leadsto R \cdot \mathsf{hypot}\left(\cos \left(\frac{1}{2} \cdot \phi_2\right) \cdot \left(\lambda_1 - \lambda_2\right), \phi_1 - \phi_2\right) \]
      4. lift--.f6490.2

        \[\leadsto R \cdot \mathsf{hypot}\left(\cos \left(0.5 \cdot \phi_2\right) \cdot \left(\lambda_1 - \color{blue}{\lambda_2}\right), \phi_1 - \phi_2\right) \]
    6. Applied rewrites90.2%

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

Alternative 2: 95.5% accurate, 1.7× speedup?

\[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ R \cdot \mathsf{hypot}\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\left(\phi_1 + \phi_2\right) \cdot 0.5\right), \phi_1 - \phi_2\right) \end{array} \]
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
  (hypot (* (- lambda1 lambda2) (cos (* (+ phi1 phi2) 0.5))) (- phi1 phi2))))
assert(R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2);
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	return R * hypot(((lambda1 - lambda2) * cos(((phi1 + phi2) * 0.5))), (phi1 - phi2));
}
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 * Math.hypot(((lambda1 - lambda2) * Math.cos(((phi1 + phi2) * 0.5))), (phi1 - phi2));
}
[R, lambda1, lambda2, phi1, phi2] = sort([R, lambda1, lambda2, phi1, phi2])
def code(R, lambda1, lambda2, phi1, phi2):
	return R * math.hypot(((lambda1 - lambda2) * math.cos(((phi1 + phi2) * 0.5))), (phi1 - phi2))
R, lambda1, lambda2, phi1, phi2 = sort([R, lambda1, lambda2, phi1, phi2])
function code(R, lambda1, lambda2, phi1, phi2)
	return Float64(R * hypot(Float64(Float64(lambda1 - lambda2) * cos(Float64(Float64(phi1 + phi2) * 0.5))), Float64(phi1 - phi2)))
end
R, lambda1, lambda2, phi1, phi2 = num2cell(sort([R, lambda1, lambda2, phi1, phi2])){:}
function tmp = code(R, lambda1, lambda2, phi1, phi2)
	tmp = R * hypot(((lambda1 - lambda2) * cos(((phi1 + phi2) * 0.5))), (phi1 - 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 * N[Sqrt[N[(N[(lambda1 - lambda2), $MachinePrecision] * N[Cos[N[(N[(phi1 + phi2), $MachinePrecision] * 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] ^ 2 + N[(phi1 - phi2), $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
[R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\
\\
R \cdot \mathsf{hypot}\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\left(\phi_1 + \phi_2\right) \cdot 0.5\right), \phi_1 - \phi_2\right)
\end{array}
Derivation
  1. Initial program 59.1%

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

      \[\leadsto R \cdot \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
    2. 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 rewrites95.5%

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

Alternative 3: 90.0% accurate, 1.8× speedup?

\[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ R \cdot \mathsf{hypot}\left(\cos \left(0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right), \phi_1 - \phi_2\right) \end{array} \]
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 (hypot (* (cos (* 0.5 phi1)) (- lambda1 lambda2)) (- phi1 phi2))))
assert(R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2);
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	return R * hypot((cos((0.5 * phi1)) * (lambda1 - lambda2)), (phi1 - phi2));
}
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 * Math.hypot((Math.cos((0.5 * phi1)) * (lambda1 - lambda2)), (phi1 - phi2));
}
[R, lambda1, lambda2, phi1, phi2] = sort([R, lambda1, lambda2, phi1, phi2])
def code(R, lambda1, lambda2, phi1, phi2):
	return R * math.hypot((math.cos((0.5 * phi1)) * (lambda1 - lambda2)), (phi1 - phi2))
R, lambda1, lambda2, phi1, phi2 = sort([R, lambda1, lambda2, phi1, phi2])
function code(R, lambda1, lambda2, phi1, phi2)
	return Float64(R * hypot(Float64(cos(Float64(0.5 * phi1)) * Float64(lambda1 - lambda2)), Float64(phi1 - phi2)))
end
R, lambda1, lambda2, phi1, phi2 = num2cell(sort([R, lambda1, lambda2, phi1, phi2])){:}
function tmp = code(R, lambda1, lambda2, phi1, phi2)
	tmp = R * hypot((cos((0.5 * phi1)) * (lambda1 - lambda2)), (phi1 - 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 * N[Sqrt[N[(N[Cos[N[(0.5 * phi1), $MachinePrecision]], $MachinePrecision] * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision] ^ 2 + N[(phi1 - phi2), $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
[R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\
\\
R \cdot \mathsf{hypot}\left(\cos \left(0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right), \phi_1 - \phi_2\right)
\end{array}
Derivation
  1. Initial program 59.1%

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

      \[\leadsto R \cdot \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
    2. 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 rewrites95.5%

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

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

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

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

      \[\leadsto R \cdot \mathsf{hypot}\left(\cos \left(\frac{1}{2} \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right), \phi_1 - \phi_2\right) \]
    4. lift--.f6490.0

      \[\leadsto R \cdot \mathsf{hypot}\left(\cos \left(0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \color{blue}{\lambda_2}\right), \phi_1 - \phi_2\right) \]
  6. Applied rewrites90.0%

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

Alternative 4: 84.7% accurate, 1.7× speedup?

\[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ \begin{array}{l} \mathbf{if}\;\lambda_1 \leq -3.1 \cdot 10^{+41}:\\ \;\;\;\;R \cdot \mathsf{hypot}\left(\lambda_1 \cdot \cos \left(0.5 \cdot \phi_1\right), \phi_1 - \phi_2\right)\\ \mathbf{else}:\\ \;\;\;\;R \cdot \mathsf{hypot}\left(1 \cdot \left(\lambda_1 - \lambda_2\right), \phi_1 - \phi_2\right)\\ \end{array} \end{array} \]
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 -3.1e+41)
   (* R (hypot (* lambda1 (cos (* 0.5 phi1))) (- phi1 phi2)))
   (* R (hypot (* 1.0 (- lambda1 lambda2)) (- phi1 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 (lambda1 <= -3.1e+41) {
		tmp = R * hypot((lambda1 * cos((0.5 * phi1))), (phi1 - phi2));
	} else {
		tmp = R * hypot((1.0 * (lambda1 - lambda2)), (phi1 - phi2));
	}
	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 (lambda1 <= -3.1e+41) {
		tmp = R * Math.hypot((lambda1 * Math.cos((0.5 * phi1))), (phi1 - phi2));
	} else {
		tmp = R * Math.hypot((1.0 * (lambda1 - lambda2)), (phi1 - phi2));
	}
	return tmp;
}
[R, lambda1, lambda2, phi1, phi2] = sort([R, lambda1, lambda2, phi1, phi2])
def code(R, lambda1, lambda2, phi1, phi2):
	tmp = 0
	if lambda1 <= -3.1e+41:
		tmp = R * math.hypot((lambda1 * math.cos((0.5 * phi1))), (phi1 - phi2))
	else:
		tmp = R * math.hypot((1.0 * (lambda1 - lambda2)), (phi1 - 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 (lambda1 <= -3.1e+41)
		tmp = Float64(R * hypot(Float64(lambda1 * cos(Float64(0.5 * phi1))), Float64(phi1 - phi2)));
	else
		tmp = Float64(R * hypot(Float64(1.0 * Float64(lambda1 - lambda2)), Float64(phi1 - 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 (lambda1 <= -3.1e+41)
		tmp = R * hypot((lambda1 * cos((0.5 * phi1))), (phi1 - phi2));
	else
		tmp = R * hypot((1.0 * (lambda1 - lambda2)), (phi1 - 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[lambda1, -3.1e+41], N[(R * N[Sqrt[N[(lambda1 * N[Cos[N[(0.5 * phi1), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] ^ 2 + N[(phi1 - phi2), $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision], N[(R * N[Sqrt[N[(1.0 * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision] ^ 2 + N[(phi1 - phi2), $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
[R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\
\\
\begin{array}{l}
\mathbf{if}\;\lambda_1 \leq -3.1 \cdot 10^{+41}:\\
\;\;\;\;R \cdot \mathsf{hypot}\left(\lambda_1 \cdot \cos \left(0.5 \cdot \phi_1\right), \phi_1 - \phi_2\right)\\

\mathbf{else}:\\
\;\;\;\;R \cdot \mathsf{hypot}\left(1 \cdot \left(\lambda_1 - \lambda_2\right), \phi_1 - \phi_2\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if lambda1 < -3.1e41

    1. Initial program 59.1%

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

        \[\leadsto R \cdot \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
      2. 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 rewrites95.5%

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

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

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

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

        \[\leadsto R \cdot \mathsf{hypot}\left(\cos \left(\frac{1}{2} \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right), \phi_1 - \phi_2\right) \]
      4. lift--.f6490.0

        \[\leadsto R \cdot \mathsf{hypot}\left(\cos \left(0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \color{blue}{\lambda_2}\right), \phi_1 - \phi_2\right) \]
    6. Applied rewrites90.0%

      \[\leadsto R \cdot \mathsf{hypot}\left(\color{blue}{\cos \left(0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right)}, \phi_1 - \phi_2\right) \]
    7. Taylor expanded in lambda1 around inf

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

        \[\leadsto R \cdot \mathsf{hypot}\left(\lambda_1 \cdot \cos \left(\frac{1}{2} \cdot \phi_1\right), \phi_1 - \phi_2\right) \]
      2. lift-cos.f64N/A

        \[\leadsto R \cdot \mathsf{hypot}\left(\lambda_1 \cdot \cos \left(\frac{1}{2} \cdot \phi_1\right), \phi_1 - \phi_2\right) \]
      3. lift-*.f6474.9

        \[\leadsto R \cdot \mathsf{hypot}\left(\lambda_1 \cdot \cos \left(0.5 \cdot \phi_1\right), \phi_1 - \phi_2\right) \]
    9. Applied rewrites74.9%

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

    if -3.1e41 < lambda1

    1. Initial program 59.1%

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

        \[\leadsto R \cdot \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
      2. 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 rewrites95.5%

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

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

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

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

        \[\leadsto R \cdot \mathsf{hypot}\left(\cos \left(\frac{1}{2} \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right), \phi_1 - \phi_2\right) \]
      4. lift--.f6490.0

        \[\leadsto R \cdot \mathsf{hypot}\left(\cos \left(0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \color{blue}{\lambda_2}\right), \phi_1 - \phi_2\right) \]
    6. Applied rewrites90.0%

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

      \[\leadsto R \cdot \mathsf{hypot}\left(1 \cdot \left(\color{blue}{\lambda_1} - \lambda_2\right), \phi_1 - \phi_2\right) \]
    8. Step-by-step derivation
      1. Applied rewrites84.7%

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

    Alternative 5: 84.7% accurate, 4.3× speedup?

    \[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ R \cdot \mathsf{hypot}\left(1 \cdot \left(\lambda_1 - \lambda_2\right), \phi_1 - \phi_2\right) \end{array} \]
    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 (hypot (* 1.0 (- lambda1 lambda2)) (- phi1 phi2))))
    assert(R < lambda1 && lambda1 < lambda2 && lambda2 < phi1 && phi1 < phi2);
    double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
    	return R * hypot((1.0 * (lambda1 - lambda2)), (phi1 - phi2));
    }
    
    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 * Math.hypot((1.0 * (lambda1 - lambda2)), (phi1 - phi2));
    }
    
    [R, lambda1, lambda2, phi1, phi2] = sort([R, lambda1, lambda2, phi1, phi2])
    def code(R, lambda1, lambda2, phi1, phi2):
    	return R * math.hypot((1.0 * (lambda1 - lambda2)), (phi1 - phi2))
    
    R, lambda1, lambda2, phi1, phi2 = sort([R, lambda1, lambda2, phi1, phi2])
    function code(R, lambda1, lambda2, phi1, phi2)
    	return Float64(R * hypot(Float64(1.0 * Float64(lambda1 - lambda2)), Float64(phi1 - phi2)))
    end
    
    R, lambda1, lambda2, phi1, phi2 = num2cell(sort([R, lambda1, lambda2, phi1, phi2])){:}
    function tmp = code(R, lambda1, lambda2, phi1, phi2)
    	tmp = R * hypot((1.0 * (lambda1 - lambda2)), (phi1 - 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 * N[Sqrt[N[(1.0 * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision] ^ 2 + N[(phi1 - phi2), $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\
    \\
    R \cdot \mathsf{hypot}\left(1 \cdot \left(\lambda_1 - \lambda_2\right), \phi_1 - \phi_2\right)
    \end{array}
    
    Derivation
    1. Initial program 59.1%

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

        \[\leadsto R \cdot \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}} \]
      2. 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 rewrites95.5%

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

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

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

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

        \[\leadsto R \cdot \mathsf{hypot}\left(\cos \left(\frac{1}{2} \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right), \phi_1 - \phi_2\right) \]
      4. lift--.f6490.0

        \[\leadsto R \cdot \mathsf{hypot}\left(\cos \left(0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \color{blue}{\lambda_2}\right), \phi_1 - \phi_2\right) \]
    6. Applied rewrites90.0%

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

      \[\leadsto R \cdot \mathsf{hypot}\left(1 \cdot \left(\color{blue}{\lambda_1} - \lambda_2\right), \phi_1 - \phi_2\right) \]
    8. Step-by-step derivation
      1. Applied rewrites84.7%

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

      Alternative 6: 58.6% accurate, 5.3× speedup?

      \[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ \begin{array}{l} \mathbf{if}\;R \leq 3.9 \cdot 10^{+67}:\\ \;\;\;\;\mathsf{fma}\left(-1, R \cdot \phi_1, R \cdot \phi_2\right)\\ \mathbf{else}:\\ \;\;\;\;\phi_2 \cdot \left(\phi_1 \cdot \left(\frac{R}{\phi_1} - \frac{R}{\phi_2}\right)\right)\\ \end{array} \end{array} \]
      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 (<= R 3.9e+67)
         (fma -1.0 (* R phi1) (* R phi2))
         (* phi2 (* phi1 (- (/ 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 (R <= 3.9e+67) {
      		tmp = fma(-1.0, (R * phi1), (R * phi2));
      	} else {
      		tmp = phi2 * (phi1 * ((R / phi1) - (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 (R <= 3.9e+67)
      		tmp = fma(-1.0, Float64(R * phi1), Float64(R * phi2));
      	else
      		tmp = Float64(phi2 * Float64(phi1 * Float64(Float64(R / phi1) - Float64(R / phi2))));
      	end
      	return 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[R, 3.9e+67], N[(-1.0 * N[(R * phi1), $MachinePrecision] + N[(R * phi2), $MachinePrecision]), $MachinePrecision], N[(phi2 * N[(phi1 * N[(N[(R / phi1), $MachinePrecision] - N[(R / phi2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
      
      \begin{array}{l}
      [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\
      \\
      \begin{array}{l}
      \mathbf{if}\;R \leq 3.9 \cdot 10^{+67}:\\
      \;\;\;\;\mathsf{fma}\left(-1, R \cdot \phi_1, R \cdot \phi_2\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\phi_2 \cdot \left(\phi_1 \cdot \left(\frac{R}{\phi_1} - \frac{R}{\phi_2}\right)\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if R < 3.90000000000000007e67

        1. Initial program 59.1%

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \mathsf{fma}\left(-1, R \cdot \color{blue}{\phi_1}, R \cdot \phi_2\right) \]
          2. lift-*.f64N/A

            \[\leadsto \mathsf{fma}\left(-1, R \cdot \phi_1, R \cdot \phi_2\right) \]
          3. lower-*.f6455.6

            \[\leadsto \mathsf{fma}\left(-1, R \cdot \phi_1, R \cdot \phi_2\right) \]
        7. Applied rewrites55.6%

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

        if 3.90000000000000007e67 < R

        1. Initial program 59.1%

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

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

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \phi_2 \cdot \left(\phi_1 \cdot \left(\frac{R}{\phi_1} - \frac{R}{\phi_2}\right)\right) \]
          4. lower-/.f6454.3

            \[\leadsto \phi_2 \cdot \left(\phi_1 \cdot \left(\frac{R}{\phi_1} - \frac{R}{\phi_2}\right)\right) \]
        7. Applied rewrites54.3%

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

      Alternative 7: 57.5% accurate, 5.7× speedup?

      \[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ \begin{array}{l} \mathbf{if}\;\phi_1 \leq -0.00385:\\ \;\;\;\;R \cdot \left(-\phi_1 \cdot \left(1 + \left(-\frac{\phi_2}{\phi_1}\right)\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\phi_2 \cdot \left(R \cdot \left(1 - \frac{\phi_1}{\phi_2}\right)\right)\\ \end{array} \end{array} \]
      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 (<= phi1 -0.00385)
         (* R (- (* phi1 (+ 1.0 (- (/ phi2 phi1))))))
         (* phi2 (* R (- 1.0 (/ phi1 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 <= -0.00385) {
      		tmp = R * -(phi1 * (1.0 + -(phi2 / phi1)));
      	} else {
      		tmp = phi2 * (R * (1.0 - (phi1 / 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 <= (-0.00385d0)) then
              tmp = r * -(phi1 * (1.0d0 + -(phi2 / phi1)))
          else
              tmp = phi2 * (r * (1.0d0 - (phi1 / 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 <= -0.00385) {
      		tmp = R * -(phi1 * (1.0 + -(phi2 / phi1)));
      	} else {
      		tmp = phi2 * (R * (1.0 - (phi1 / 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 <= -0.00385:
      		tmp = R * -(phi1 * (1.0 + -(phi2 / phi1)))
      	else:
      		tmp = phi2 * (R * (1.0 - (phi1 / 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 <= -0.00385)
      		tmp = Float64(R * Float64(-Float64(phi1 * Float64(1.0 + Float64(-Float64(phi2 / phi1))))));
      	else
      		tmp = Float64(phi2 * Float64(R * Float64(1.0 - Float64(phi1 / 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 <= -0.00385)
      		tmp = R * -(phi1 * (1.0 + -(phi2 / phi1)));
      	else
      		tmp = phi2 * (R * (1.0 - (phi1 / 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, -0.00385], N[(R * (-N[(phi1 * N[(1.0 + (-N[(phi2 / phi1), $MachinePrecision])), $MachinePrecision]), $MachinePrecision])), $MachinePrecision], N[(phi2 * N[(R * N[(1.0 - N[(phi1 / phi2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
      
      \begin{array}{l}
      [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\
      \\
      \begin{array}{l}
      \mathbf{if}\;\phi_1 \leq -0.00385:\\
      \;\;\;\;R \cdot \left(-\phi_1 \cdot \left(1 + \left(-\frac{\phi_2}{\phi_1}\right)\right)\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\phi_2 \cdot \left(R \cdot \left(1 - \frac{\phi_1}{\phi_2}\right)\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if phi1 < -0.0038500000000000001

        1. Initial program 59.1%

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

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

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

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

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

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

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

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

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

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

        if -0.0038500000000000001 < phi1

        1. Initial program 59.1%

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

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \phi_2 \cdot \left(R \cdot \left(1 - \frac{\phi_1}{\color{blue}{\phi_2}}\right)\right) \]
          3. lift-/.f6453.3

            \[\leadsto \phi_2 \cdot \left(R \cdot \left(1 - \frac{\phi_1}{\phi_2}\right)\right) \]
        7. Applied rewrites53.3%

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

      Alternative 8: 56.7% accurate, 5.5× speedup?

      \[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ \begin{array}{l} \mathbf{if}\;\lambda_1 - \lambda_2 \leq -1.8 \cdot 10^{+180}:\\ \;\;\;\;\phi_2 \cdot \left(R \cdot \left(1 - \frac{\phi_1}{\phi_2}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(-1, R \cdot \phi_1, R \cdot \phi_2\right)\\ \end{array} \end{array} \]
      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) -1.8e+180)
         (* phi2 (* R (- 1.0 (/ phi1 phi2))))
         (fma -1.0 (* 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 ((lambda1 - lambda2) <= -1.8e+180) {
      		tmp = phi2 * (R * (1.0 - (phi1 / phi2)));
      	} else {
      		tmp = fma(-1.0, (R * phi1), (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 (Float64(lambda1 - lambda2) <= -1.8e+180)
      		tmp = Float64(phi2 * Float64(R * Float64(1.0 - Float64(phi1 / phi2))));
      	else
      		tmp = fma(-1.0, Float64(R * phi1), Float64(R * phi2));
      	end
      	return 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], -1.8e+180], N[(phi2 * N[(R * N[(1.0 - N[(phi1 / phi2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(-1.0 * N[(R * phi1), $MachinePrecision] + N[(R * phi2), $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 -1.8 \cdot 10^{+180}:\\
      \;\;\;\;\phi_2 \cdot \left(R \cdot \left(1 - \frac{\phi_1}{\phi_2}\right)\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\mathsf{fma}\left(-1, R \cdot \phi_1, R \cdot \phi_2\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (-.f64 lambda1 lambda2) < -1.8000000000000001e180

        1. Initial program 59.1%

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

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \phi_2 \cdot \left(R \cdot \left(1 - \frac{\phi_1}{\color{blue}{\phi_2}}\right)\right) \]
          3. lift-/.f6453.3

            \[\leadsto \phi_2 \cdot \left(R \cdot \left(1 - \frac{\phi_1}{\phi_2}\right)\right) \]
        7. Applied rewrites53.3%

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

        if -1.8000000000000001e180 < (-.f64 lambda1 lambda2)

        1. Initial program 59.1%

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \mathsf{fma}\left(-1, R \cdot \color{blue}{\phi_1}, R \cdot \phi_2\right) \]
          2. lift-*.f64N/A

            \[\leadsto \mathsf{fma}\left(-1, R \cdot \phi_1, R \cdot \phi_2\right) \]
          3. lower-*.f6455.6

            \[\leadsto \mathsf{fma}\left(-1, R \cdot \phi_1, R \cdot \phi_2\right) \]
        7. Applied rewrites55.6%

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

      Alternative 9: 56.2% accurate, 6.8× speedup?

      \[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ \begin{array}{l} \mathbf{if}\;\phi_2 \leq -4.2 \cdot 10^{-27}:\\ \;\;\;\;R \cdot \left(-\phi_1\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(-1, R \cdot \phi_1, R \cdot \phi_2\right)\\ \end{array} \end{array} \]
      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 (<= phi2 -4.2e-27) (* R (- phi1)) (fma -1.0 (* 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 (phi2 <= -4.2e-27) {
      		tmp = R * -phi1;
      	} else {
      		tmp = fma(-1.0, (R * phi1), (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 (phi2 <= -4.2e-27)
      		tmp = Float64(R * Float64(-phi1));
      	else
      		tmp = fma(-1.0, Float64(R * phi1), Float64(R * phi2));
      	end
      	return 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, -4.2e-27], N[(R * (-phi1)), $MachinePrecision], N[(-1.0 * N[(R * phi1), $MachinePrecision] + N[(R * phi2), $MachinePrecision]), $MachinePrecision]]
      
      \begin{array}{l}
      [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\
      \\
      \begin{array}{l}
      \mathbf{if}\;\phi_2 \leq -4.2 \cdot 10^{-27}:\\
      \;\;\;\;R \cdot \left(-\phi_1\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\mathsf{fma}\left(-1, R \cdot \phi_1, R \cdot \phi_2\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if phi2 < -4.20000000000000031e-27

        1. Initial program 59.1%

          \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
        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.f6431.8

            \[\leadsto R \cdot \left(-\phi_1\right) \]
        4. Applied rewrites31.8%

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

        if -4.20000000000000031e-27 < phi2

        1. Initial program 59.1%

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \mathsf{fma}\left(-1, R \cdot \color{blue}{\phi_1}, R \cdot \phi_2\right) \]
          2. lift-*.f64N/A

            \[\leadsto \mathsf{fma}\left(-1, R \cdot \phi_1, R \cdot \phi_2\right) \]
          3. lower-*.f6455.6

            \[\leadsto \mathsf{fma}\left(-1, R \cdot \phi_1, R \cdot \phi_2\right) \]
        7. Applied rewrites55.6%

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

      Alternative 10: 52.5% accurate, 12.2× speedup?

      \[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ \begin{array}{l} \mathbf{if}\;\phi_1 \leq -5.5 \cdot 10^{-6}:\\ \;\;\;\;R \cdot \left(-\phi_1\right)\\ \mathbf{else}:\\ \;\;\;\;R \cdot \phi_2\\ \end{array} \end{array} \]
      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 -5.5e-6) (* 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 <= -5.5e-6) {
      		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 <= (-5.5d-6)) 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 <= -5.5e-6) {
      		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 <= -5.5e-6:
      		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 <= -5.5e-6)
      		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 <= -5.5e-6)
      		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, -5.5e-6], 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 -5.5 \cdot 10^{-6}:\\
      \;\;\;\;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 < -5.4999999999999999e-6

        1. Initial program 59.1%

          \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
        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.f6431.8

            \[\leadsto R \cdot \left(-\phi_1\right) \]
        4. Applied rewrites31.8%

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

        if -5.4999999999999999e-6 < phi1

        1. Initial program 59.1%

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

          \[\leadsto \color{blue}{R \cdot \phi_2} \]
        3. Step-by-step derivation
          1. lower-*.f6430.8

            \[\leadsto R \cdot \color{blue}{\phi_2} \]
        4. Applied rewrites30.8%

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

      Alternative 11: 32.5% accurate, 12.2× speedup?

      \[\begin{array}{l} [R, lambda1, lambda2, phi1, phi2] = \mathsf{sort}([R, lambda1, lambda2, phi1, phi2])\\ \\ \begin{array}{l} \mathbf{if}\;\phi_2 \leq -1 \cdot 10^{-297}:\\ \;\;\;\;-R \cdot \phi_2\\ \mathbf{else}:\\ \;\;\;\;R \cdot \phi_2\\ \end{array} \end{array} \]
      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 (<= phi2 -1e-297) (- (* R phi2)) (* 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 (phi2 <= -1e-297) {
      		tmp = -(R * phi2);
      	} 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 (phi2 <= (-1d-297)) then
              tmp = -(r * phi2)
          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 (phi2 <= -1e-297) {
      		tmp = -(R * phi2);
      	} 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 phi2 <= -1e-297:
      		tmp = -(R * phi2)
      	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 (phi2 <= -1e-297)
      		tmp = Float64(-Float64(R * phi2));
      	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 (phi2 <= -1e-297)
      		tmp = -(R * phi2);
      	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[phi2, -1e-297], (-N[(R * phi2), $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_2 \leq -1 \cdot 10^{-297}:\\
      \;\;\;\;-R \cdot \phi_2\\
      
      \mathbf{else}:\\
      \;\;\;\;R \cdot \phi_2\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if phi2 < -1.00000000000000004e-297

        1. Initial program 59.1%

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

          \[\leadsto \color{blue}{-1 \cdot \left(R \cdot \phi_2\right)} \]
        3. Step-by-step derivation
          1. mul-1-negN/A

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

            \[\leadsto -R \cdot \phi_2 \]
          3. lower-*.f643.7

            \[\leadsto -R \cdot \phi_2 \]
        4. Applied rewrites3.7%

          \[\leadsto \color{blue}{-R \cdot \phi_2} \]

        if -1.00000000000000004e-297 < phi2

        1. Initial program 59.1%

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

          \[\leadsto \color{blue}{R \cdot \phi_2} \]
        3. Step-by-step derivation
          1. lower-*.f6430.8

            \[\leadsto R \cdot \color{blue}{\phi_2} \]
        4. Applied rewrites30.8%

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

      Alternative 12: 30.8% 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 59.1%

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

        \[\leadsto \color{blue}{R \cdot \phi_2} \]
      3. Step-by-step derivation
        1. lower-*.f6430.8

          \[\leadsto R \cdot \color{blue}{\phi_2} \]
      4. Applied rewrites30.8%

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

      Alternative 13: 3.6% 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 59.1%

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

        \[\leadsto \color{blue}{R \cdot \phi_1} \]
      3. Step-by-step derivation
        1. lower-*.f643.6

          \[\leadsto R \cdot \color{blue}{\phi_1} \]
      4. Applied rewrites3.6%

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

      Reproduce

      ?
      herbie shell --seed 2025140 
      (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))))))