Equirectangular approximation to distance on a great circle

Percentage Accurate: 60.0% → 99.9%
Time: 7.1s
Alternatives: 12
Speedup: 1.9×

Specification

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

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 12 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: 60.0% accurate, 1.0× speedup?

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

Alternative 1: 99.9% accurate, 0.6× speedup?

\[\mathsf{hypot}\left(\phi_2 - \phi_1, \mathsf{fma}\left(\cos \left(0.5 \cdot \phi_1\right), \cos \left(-0.5 \cdot \phi_2\right), \sin \left(0.5 \cdot \phi_1\right) \cdot \sin \left(-0.5 \cdot \phi_2\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
(FPCore (R lambda1 lambda2 phi1 phi2)
 :precision binary64
 (*
  (hypot
   (- phi2 phi1)
   (*
    (fma
     (cos (* 0.5 phi1))
     (cos (* -0.5 phi2))
     (* (sin (* 0.5 phi1)) (sin (* -0.5 phi2))))
    (- lambda1 lambda2)))
  R))
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	return hypot((phi2 - phi1), (fma(cos((0.5 * phi1)), cos((-0.5 * phi2)), (sin((0.5 * phi1)) * sin((-0.5 * phi2)))) * (lambda1 - lambda2))) * R;
}
function code(R, lambda1, lambda2, phi1, phi2)
	return Float64(hypot(Float64(phi2 - phi1), Float64(fma(cos(Float64(0.5 * phi1)), cos(Float64(-0.5 * phi2)), Float64(sin(Float64(0.5 * phi1)) * sin(Float64(-0.5 * phi2)))) * Float64(lambda1 - lambda2))) * R)
end
code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(N[Sqrt[N[(phi2 - phi1), $MachinePrecision] ^ 2 + N[(N[(N[Cos[N[(0.5 * phi1), $MachinePrecision]], $MachinePrecision] * N[Cos[N[(-0.5 * phi2), $MachinePrecision]], $MachinePrecision] + N[(N[Sin[N[(0.5 * phi1), $MachinePrecision]], $MachinePrecision] * N[Sin[N[(-0.5 * phi2), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision] * R), $MachinePrecision]
\mathsf{hypot}\left(\phi_2 - \phi_1, \mathsf{fma}\left(\cos \left(0.5 \cdot \phi_1\right), \cos \left(-0.5 \cdot \phi_2\right), \sin \left(0.5 \cdot \phi_1\right) \cdot \sin \left(-0.5 \cdot \phi_2\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R
Derivation
  1. Initial program 60.0%

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

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

      \[\leadsto \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \cdot R} \]
    3. lower-*.f6460.0%

      \[\leadsto \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \cdot R} \]
  3. Applied rewrites96.0%

    \[\leadsto \color{blue}{\mathsf{hypot}\left(\phi_2 - \phi_1, \cos \left(\left(\phi_2 + \phi_1\right) \cdot -0.5\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R} \]
  4. Step-by-step derivation
    1. lift-cos.f64N/A

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

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

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

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

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

      \[\leadsto \mathsf{hypot}\left(\phi_2 - \phi_1, \cos \left(\left(\phi_1 + \phi_2\right) \cdot \color{blue}{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
    7. distribute-rgt-neg-inN/A

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

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

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

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

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

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

      \[\leadsto \mathsf{hypot}\left(\phi_2 - \phi_1, \cos \color{blue}{\left(\frac{1}{2} \cdot \phi_1 + \frac{1}{2} \cdot \phi_2\right)} \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
    14. fp-cancel-sign-sub-invN/A

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

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

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

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

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

      \[\leadsto \mathsf{hypot}\left(\phi_2 - \phi_1, \color{blue}{\mathsf{fma}\left(\cos \left(\frac{\phi_1}{2}\right), \cos \left(\left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot \phi_2\right), \sin \left(\frac{\phi_1}{2}\right) \cdot \sin \left(\left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot \phi_2\right)\right)} \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
  5. Applied rewrites99.9%

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

Alternative 2: 96.0% accurate, 0.5× speedup?

\[\begin{array}{l} t_0 := 0.5 \cdot \mathsf{min}\left(\phi_1, \phi_2\right)\\ t_1 := -0.5 \cdot \mathsf{max}\left(\phi_1, \phi_2\right)\\ t_2 := \mathsf{min}\left(\lambda_1, \lambda_2\right) - \mathsf{max}\left(\lambda_1, \lambda_2\right)\\ \mathbf{if}\;\mathsf{min}\left(\lambda_1, \lambda_2\right) \leq -2 \cdot 10^{+106}:\\ \;\;\;\;\mathsf{hypot}\left(\mathsf{max}\left(\phi_1, \phi_2\right), \mathsf{fma}\left(\cos t\_0, \cos t\_1, \sin t\_0 \cdot \sin t\_1\right) \cdot t\_2\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\mathsf{hypot}\left(\mathsf{max}\left(\phi_1, \phi_2\right) - \mathsf{min}\left(\phi_1, \phi_2\right), \cos \left(\left(\mathsf{max}\left(\phi_1, \phi_2\right) + \mathsf{min}\left(\phi_1, \phi_2\right)\right) \cdot -0.5\right) \cdot t\_2\right) \cdot R\\ \end{array} \]
(FPCore (R lambda1 lambda2 phi1 phi2)
 :precision binary64
 (let* ((t_0 (* 0.5 (fmin phi1 phi2)))
        (t_1 (* -0.5 (fmax phi1 phi2)))
        (t_2 (- (fmin lambda1 lambda2) (fmax lambda1 lambda2))))
   (if (<= (fmin lambda1 lambda2) -2e+106)
     (*
      (hypot
       (fmax phi1 phi2)
       (* (fma (cos t_0) (cos t_1) (* (sin t_0) (sin t_1))) t_2))
      R)
     (*
      (hypot
       (- (fmax phi1 phi2) (fmin phi1 phi2))
       (* (cos (* (+ (fmax phi1 phi2) (fmin phi1 phi2)) -0.5)) t_2))
      R))))
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double t_0 = 0.5 * fmin(phi1, phi2);
	double t_1 = -0.5 * fmax(phi1, phi2);
	double t_2 = fmin(lambda1, lambda2) - fmax(lambda1, lambda2);
	double tmp;
	if (fmin(lambda1, lambda2) <= -2e+106) {
		tmp = hypot(fmax(phi1, phi2), (fma(cos(t_0), cos(t_1), (sin(t_0) * sin(t_1))) * t_2)) * R;
	} else {
		tmp = hypot((fmax(phi1, phi2) - fmin(phi1, phi2)), (cos(((fmax(phi1, phi2) + fmin(phi1, phi2)) * -0.5)) * t_2)) * R;
	}
	return tmp;
}
function code(R, lambda1, lambda2, phi1, phi2)
	t_0 = Float64(0.5 * fmin(phi1, phi2))
	t_1 = Float64(-0.5 * fmax(phi1, phi2))
	t_2 = Float64(fmin(lambda1, lambda2) - fmax(lambda1, lambda2))
	tmp = 0.0
	if (fmin(lambda1, lambda2) <= -2e+106)
		tmp = Float64(hypot(fmax(phi1, phi2), Float64(fma(cos(t_0), cos(t_1), Float64(sin(t_0) * sin(t_1))) * t_2)) * R);
	else
		tmp = Float64(hypot(Float64(fmax(phi1, phi2) - fmin(phi1, phi2)), Float64(cos(Float64(Float64(fmax(phi1, phi2) + fmin(phi1, phi2)) * -0.5)) * t_2)) * R);
	end
	return tmp
end
code[R_, lambda1_, lambda2_, phi1_, phi2_] := Block[{t$95$0 = N[(0.5 * N[Min[phi1, phi2], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(-0.5 * N[Max[phi1, phi2], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[Min[lambda1, lambda2], $MachinePrecision] - N[Max[lambda1, lambda2], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[Min[lambda1, lambda2], $MachinePrecision], -2e+106], N[(N[Sqrt[N[Max[phi1, phi2], $MachinePrecision] ^ 2 + N[(N[(N[Cos[t$95$0], $MachinePrecision] * N[Cos[t$95$1], $MachinePrecision] + N[(N[Sin[t$95$0], $MachinePrecision] * N[Sin[t$95$1], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * t$95$2), $MachinePrecision] ^ 2], $MachinePrecision] * R), $MachinePrecision], N[(N[Sqrt[N[(N[Max[phi1, phi2], $MachinePrecision] - N[Min[phi1, phi2], $MachinePrecision]), $MachinePrecision] ^ 2 + N[(N[Cos[N[(N[(N[Max[phi1, phi2], $MachinePrecision] + N[Min[phi1, phi2], $MachinePrecision]), $MachinePrecision] * -0.5), $MachinePrecision]], $MachinePrecision] * t$95$2), $MachinePrecision] ^ 2], $MachinePrecision] * R), $MachinePrecision]]]]]
\begin{array}{l}
t_0 := 0.5 \cdot \mathsf{min}\left(\phi_1, \phi_2\right)\\
t_1 := -0.5 \cdot \mathsf{max}\left(\phi_1, \phi_2\right)\\
t_2 := \mathsf{min}\left(\lambda_1, \lambda_2\right) - \mathsf{max}\left(\lambda_1, \lambda_2\right)\\
\mathbf{if}\;\mathsf{min}\left(\lambda_1, \lambda_2\right) \leq -2 \cdot 10^{+106}:\\
\;\;\;\;\mathsf{hypot}\left(\mathsf{max}\left(\phi_1, \phi_2\right), \mathsf{fma}\left(\cos t\_0, \cos t\_1, \sin t\_0 \cdot \sin t\_1\right) \cdot t\_2\right) \cdot R\\

\mathbf{else}:\\
\;\;\;\;\mathsf{hypot}\left(\mathsf{max}\left(\phi_1, \phi_2\right) - \mathsf{min}\left(\phi_1, \phi_2\right), \cos \left(\left(\mathsf{max}\left(\phi_1, \phi_2\right) + \mathsf{min}\left(\phi_1, \phi_2\right)\right) \cdot -0.5\right) \cdot t\_2\right) \cdot R\\


\end{array}
Derivation
  1. Split input into 2 regimes
  2. if lambda1 < -2.00000000000000018e106

    1. Initial program 60.0%

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

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

        \[\leadsto \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \cdot R} \]
      3. lower-*.f6460.0%

        \[\leadsto \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \cdot R} \]
    3. Applied rewrites96.0%

      \[\leadsto \color{blue}{\mathsf{hypot}\left(\phi_2 - \phi_1, \cos \left(\left(\phi_2 + \phi_1\right) \cdot -0.5\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R} \]
    4. Step-by-step derivation
      1. lift-cos.f64N/A

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

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

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

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

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

        \[\leadsto \mathsf{hypot}\left(\phi_2 - \phi_1, \cos \left(\left(\phi_1 + \phi_2\right) \cdot \color{blue}{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
      7. distribute-rgt-neg-inN/A

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

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

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

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

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

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

        \[\leadsto \mathsf{hypot}\left(\phi_2 - \phi_1, \cos \color{blue}{\left(\frac{1}{2} \cdot \phi_1 + \frac{1}{2} \cdot \phi_2\right)} \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
      14. fp-cancel-sign-sub-invN/A

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

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

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

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

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

        \[\leadsto \mathsf{hypot}\left(\phi_2 - \phi_1, \color{blue}{\mathsf{fma}\left(\cos \left(\frac{\phi_1}{2}\right), \cos \left(\left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot \phi_2\right), \sin \left(\frac{\phi_1}{2}\right) \cdot \sin \left(\left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot \phi_2\right)\right)} \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
    5. Applied rewrites99.9%

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

      \[\leadsto \mathsf{hypot}\left(\color{blue}{\phi_2}, \mathsf{fma}\left(\cos \left(0.5 \cdot \phi_1\right), \cos \left(-0.5 \cdot \phi_2\right), \sin \left(0.5 \cdot \phi_1\right) \cdot \sin \left(-0.5 \cdot \phi_2\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
    7. Step-by-step derivation
      1. Applied rewrites79.6%

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

      if -2.00000000000000018e106 < lambda1

      1. Initial program 60.0%

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

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

          \[\leadsto \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \cdot R} \]
        3. lower-*.f6460.0%

          \[\leadsto \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \cdot R} \]
      3. Applied rewrites96.0%

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

    Alternative 3: 95.3% accurate, 1.7× speedup?

    \[\mathsf{hypot}\left(\phi_2 - \phi_1, \cos \left(\left(\phi_2 + \phi_1\right) \cdot -0.5\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
    (FPCore (R lambda1 lambda2 phi1 phi2)
     :precision binary64
     (*
      (hypot (- phi2 phi1) (* (cos (* (+ phi2 phi1) -0.5)) (- lambda1 lambda2)))
      R))
    double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
    	return hypot((phi2 - phi1), (cos(((phi2 + phi1) * -0.5)) * (lambda1 - lambda2))) * R;
    }
    
    public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
    	return Math.hypot((phi2 - phi1), (Math.cos(((phi2 + phi1) * -0.5)) * (lambda1 - lambda2))) * R;
    }
    
    def code(R, lambda1, lambda2, phi1, phi2):
    	return math.hypot((phi2 - phi1), (math.cos(((phi2 + phi1) * -0.5)) * (lambda1 - lambda2))) * R
    
    function code(R, lambda1, lambda2, phi1, phi2)
    	return Float64(hypot(Float64(phi2 - phi1), Float64(cos(Float64(Float64(phi2 + phi1) * -0.5)) * Float64(lambda1 - lambda2))) * R)
    end
    
    function tmp = code(R, lambda1, lambda2, phi1, phi2)
    	tmp = hypot((phi2 - phi1), (cos(((phi2 + phi1) * -0.5)) * (lambda1 - lambda2))) * R;
    end
    
    code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(N[Sqrt[N[(phi2 - phi1), $MachinePrecision] ^ 2 + N[(N[Cos[N[(N[(phi2 + phi1), $MachinePrecision] * -0.5), $MachinePrecision]], $MachinePrecision] * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision] * R), $MachinePrecision]
    
    \mathsf{hypot}\left(\phi_2 - \phi_1, \cos \left(\left(\phi_2 + \phi_1\right) \cdot -0.5\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R
    
    Derivation
    1. Initial program 60.0%

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

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

        \[\leadsto \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \cdot R} \]
      3. lower-*.f6460.0%

        \[\leadsto \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \cdot R} \]
    3. Applied rewrites96.0%

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

    Alternative 4: 95.2% accurate, 1.4× speedup?

    \[\begin{array}{l} t_0 := \mathsf{max}\left(\phi_1, \phi_2\right) - \mathsf{min}\left(\phi_1, \phi_2\right)\\ \mathbf{if}\;\mathsf{min}\left(\phi_1, \phi_2\right) \leq -6.5 \cdot 10^{+17}:\\ \;\;\;\;\mathsf{hypot}\left(t\_0, \cos \left(-0.5 \cdot \mathsf{min}\left(\phi_1, \phi_2\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\mathsf{hypot}\left(t\_0, \cos \left(-0.5 \cdot \mathsf{max}\left(\phi_1, \phi_2\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R\\ \end{array} \]
    (FPCore (R lambda1 lambda2 phi1 phi2)
     :precision binary64
     (let* ((t_0 (- (fmax phi1 phi2) (fmin phi1 phi2))))
       (if (<= (fmin phi1 phi2) -6.5e+17)
         (* (hypot t_0 (* (cos (* -0.5 (fmin phi1 phi2))) (- lambda1 lambda2))) R)
         (*
          (hypot t_0 (* (cos (* -0.5 (fmax phi1 phi2))) (- lambda1 lambda2)))
          R))))
    double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
    	double t_0 = fmax(phi1, phi2) - fmin(phi1, phi2);
    	double tmp;
    	if (fmin(phi1, phi2) <= -6.5e+17) {
    		tmp = hypot(t_0, (cos((-0.5 * fmin(phi1, phi2))) * (lambda1 - lambda2))) * R;
    	} else {
    		tmp = hypot(t_0, (cos((-0.5 * fmax(phi1, phi2))) * (lambda1 - lambda2))) * R;
    	}
    	return tmp;
    }
    
    public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
    	double t_0 = fmax(phi1, phi2) - fmin(phi1, phi2);
    	double tmp;
    	if (fmin(phi1, phi2) <= -6.5e+17) {
    		tmp = Math.hypot(t_0, (Math.cos((-0.5 * fmin(phi1, phi2))) * (lambda1 - lambda2))) * R;
    	} else {
    		tmp = Math.hypot(t_0, (Math.cos((-0.5 * fmax(phi1, phi2))) * (lambda1 - lambda2))) * R;
    	}
    	return tmp;
    }
    
    def code(R, lambda1, lambda2, phi1, phi2):
    	t_0 = fmax(phi1, phi2) - fmin(phi1, phi2)
    	tmp = 0
    	if fmin(phi1, phi2) <= -6.5e+17:
    		tmp = math.hypot(t_0, (math.cos((-0.5 * fmin(phi1, phi2))) * (lambda1 - lambda2))) * R
    	else:
    		tmp = math.hypot(t_0, (math.cos((-0.5 * fmax(phi1, phi2))) * (lambda1 - lambda2))) * R
    	return tmp
    
    function code(R, lambda1, lambda2, phi1, phi2)
    	t_0 = Float64(fmax(phi1, phi2) - fmin(phi1, phi2))
    	tmp = 0.0
    	if (fmin(phi1, phi2) <= -6.5e+17)
    		tmp = Float64(hypot(t_0, Float64(cos(Float64(-0.5 * fmin(phi1, phi2))) * Float64(lambda1 - lambda2))) * R);
    	else
    		tmp = Float64(hypot(t_0, Float64(cos(Float64(-0.5 * fmax(phi1, phi2))) * Float64(lambda1 - lambda2))) * R);
    	end
    	return tmp
    end
    
    function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
    	t_0 = max(phi1, phi2) - min(phi1, phi2);
    	tmp = 0.0;
    	if (min(phi1, phi2) <= -6.5e+17)
    		tmp = hypot(t_0, (cos((-0.5 * min(phi1, phi2))) * (lambda1 - lambda2))) * R;
    	else
    		tmp = hypot(t_0, (cos((-0.5 * max(phi1, phi2))) * (lambda1 - lambda2))) * R;
    	end
    	tmp_2 = tmp;
    end
    
    code[R_, lambda1_, lambda2_, phi1_, phi2_] := Block[{t$95$0 = N[(N[Max[phi1, phi2], $MachinePrecision] - N[Min[phi1, phi2], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[Min[phi1, phi2], $MachinePrecision], -6.5e+17], N[(N[Sqrt[t$95$0 ^ 2 + N[(N[Cos[N[(-0.5 * N[Min[phi1, phi2], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision] * R), $MachinePrecision], N[(N[Sqrt[t$95$0 ^ 2 + N[(N[Cos[N[(-0.5 * N[Max[phi1, phi2], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision] * R), $MachinePrecision]]]
    
    \begin{array}{l}
    t_0 := \mathsf{max}\left(\phi_1, \phi_2\right) - \mathsf{min}\left(\phi_1, \phi_2\right)\\
    \mathbf{if}\;\mathsf{min}\left(\phi_1, \phi_2\right) \leq -6.5 \cdot 10^{+17}:\\
    \;\;\;\;\mathsf{hypot}\left(t\_0, \cos \left(-0.5 \cdot \mathsf{min}\left(\phi_1, \phi_2\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{hypot}\left(t\_0, \cos \left(-0.5 \cdot \mathsf{max}\left(\phi_1, \phi_2\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R\\
    
    
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if phi1 < -6.5e17

      1. Initial program 60.0%

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

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

          \[\leadsto \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \cdot R} \]
        3. lower-*.f6460.0%

          \[\leadsto \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \cdot R} \]
      3. Applied rewrites96.0%

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

        \[\leadsto \mathsf{hypot}\left(\phi_2 - \phi_1, \cos \color{blue}{\left(\frac{-1}{2} \cdot \phi_1\right)} \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
      5. Step-by-step derivation
        1. lower-*.f6490.5%

          \[\leadsto \mathsf{hypot}\left(\phi_2 - \phi_1, \cos \left(-0.5 \cdot \color{blue}{\phi_1}\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
      6. Applied rewrites90.5%

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

      if -6.5e17 < phi1

      1. Initial program 60.0%

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

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

          \[\leadsto \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \cdot R} \]
        3. lower-*.f6460.0%

          \[\leadsto \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \cdot R} \]
      3. Applied rewrites96.0%

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

        \[\leadsto \mathsf{hypot}\left(\phi_2 - \phi_1, \cos \color{blue}{\left(\frac{-1}{2} \cdot \phi_2\right)} \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
      5. Step-by-step derivation
        1. lower-*.f6490.2%

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

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

    Alternative 5: 90.5% accurate, 1.8× speedup?

    \[\mathsf{hypot}\left(\phi_2 - \phi_1, \cos \left(-0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
    (FPCore (R lambda1 lambda2 phi1 phi2)
     :precision binary64
     (* (hypot (- phi2 phi1) (* (cos (* -0.5 phi1)) (- lambda1 lambda2))) R))
    double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
    	return hypot((phi2 - phi1), (cos((-0.5 * phi1)) * (lambda1 - lambda2))) * R;
    }
    
    public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
    	return Math.hypot((phi2 - phi1), (Math.cos((-0.5 * phi1)) * (lambda1 - lambda2))) * R;
    }
    
    def code(R, lambda1, lambda2, phi1, phi2):
    	return math.hypot((phi2 - phi1), (math.cos((-0.5 * phi1)) * (lambda1 - lambda2))) * R
    
    function code(R, lambda1, lambda2, phi1, phi2)
    	return Float64(hypot(Float64(phi2 - phi1), Float64(cos(Float64(-0.5 * phi1)) * Float64(lambda1 - lambda2))) * R)
    end
    
    function tmp = code(R, lambda1, lambda2, phi1, phi2)
    	tmp = hypot((phi2 - phi1), (cos((-0.5 * phi1)) * (lambda1 - lambda2))) * R;
    end
    
    code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(N[Sqrt[N[(phi2 - phi1), $MachinePrecision] ^ 2 + N[(N[Cos[N[(-0.5 * phi1), $MachinePrecision]], $MachinePrecision] * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision] * R), $MachinePrecision]
    
    \mathsf{hypot}\left(\phi_2 - \phi_1, \cos \left(-0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R
    
    Derivation
    1. Initial program 60.0%

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

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

        \[\leadsto \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \cdot R} \]
      3. lower-*.f6460.0%

        \[\leadsto \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \cdot R} \]
    3. Applied rewrites96.0%

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

      \[\leadsto \mathsf{hypot}\left(\phi_2 - \phi_1, \cos \color{blue}{\left(\frac{-1}{2} \cdot \phi_1\right)} \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
    5. Step-by-step derivation
      1. lower-*.f6490.5%

        \[\leadsto \mathsf{hypot}\left(\phi_2 - \phi_1, \cos \left(-0.5 \cdot \color{blue}{\phi_1}\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
    6. Applied rewrites90.5%

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

    Alternative 6: 81.8% accurate, 1.5× speedup?

    \[\begin{array}{l} \mathbf{if}\;\mathsf{min}\left(\phi_1, \phi_2\right) \leq -4.3 \cdot 10^{+92}:\\ \;\;\;\;\left(\mathsf{max}\left(\phi_1, \phi_2\right) - \mathsf{min}\left(\phi_1, \phi_2\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\mathsf{hypot}\left(\mathsf{max}\left(\phi_1, \phi_2\right), \cos \left(-0.5 \cdot \mathsf{min}\left(\phi_1, \phi_2\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R\\ \end{array} \]
    (FPCore (R lambda1 lambda2 phi1 phi2)
     :precision binary64
     (if (<= (fmin phi1 phi2) -4.3e+92)
       (* (- (fmax phi1 phi2) (fmin phi1 phi2)) R)
       (*
        (hypot
         (fmax phi1 phi2)
         (* (cos (* -0.5 (fmin phi1 phi2))) (- lambda1 lambda2)))
        R)))
    double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
    	double tmp;
    	if (fmin(phi1, phi2) <= -4.3e+92) {
    		tmp = (fmax(phi1, phi2) - fmin(phi1, phi2)) * R;
    	} else {
    		tmp = hypot(fmax(phi1, phi2), (cos((-0.5 * fmin(phi1, phi2))) * (lambda1 - lambda2))) * R;
    	}
    	return tmp;
    }
    
    public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
    	double tmp;
    	if (fmin(phi1, phi2) <= -4.3e+92) {
    		tmp = (fmax(phi1, phi2) - fmin(phi1, phi2)) * R;
    	} else {
    		tmp = Math.hypot(fmax(phi1, phi2), (Math.cos((-0.5 * fmin(phi1, phi2))) * (lambda1 - lambda2))) * R;
    	}
    	return tmp;
    }
    
    def code(R, lambda1, lambda2, phi1, phi2):
    	tmp = 0
    	if fmin(phi1, phi2) <= -4.3e+92:
    		tmp = (fmax(phi1, phi2) - fmin(phi1, phi2)) * R
    	else:
    		tmp = math.hypot(fmax(phi1, phi2), (math.cos((-0.5 * fmin(phi1, phi2))) * (lambda1 - lambda2))) * R
    	return tmp
    
    function code(R, lambda1, lambda2, phi1, phi2)
    	tmp = 0.0
    	if (fmin(phi1, phi2) <= -4.3e+92)
    		tmp = Float64(Float64(fmax(phi1, phi2) - fmin(phi1, phi2)) * R);
    	else
    		tmp = Float64(hypot(fmax(phi1, phi2), Float64(cos(Float64(-0.5 * fmin(phi1, phi2))) * Float64(lambda1 - lambda2))) * R);
    	end
    	return tmp
    end
    
    function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
    	tmp = 0.0;
    	if (min(phi1, phi2) <= -4.3e+92)
    		tmp = (max(phi1, phi2) - min(phi1, phi2)) * R;
    	else
    		tmp = hypot(max(phi1, phi2), (cos((-0.5 * min(phi1, phi2))) * (lambda1 - lambda2))) * R;
    	end
    	tmp_2 = tmp;
    end
    
    code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[LessEqual[N[Min[phi1, phi2], $MachinePrecision], -4.3e+92], N[(N[(N[Max[phi1, phi2], $MachinePrecision] - N[Min[phi1, phi2], $MachinePrecision]), $MachinePrecision] * R), $MachinePrecision], N[(N[Sqrt[N[Max[phi1, phi2], $MachinePrecision] ^ 2 + N[(N[Cos[N[(-0.5 * N[Min[phi1, phi2], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision] * R), $MachinePrecision]]
    
    \begin{array}{l}
    \mathbf{if}\;\mathsf{min}\left(\phi_1, \phi_2\right) \leq -4.3 \cdot 10^{+92}:\\
    \;\;\;\;\left(\mathsf{max}\left(\phi_1, \phi_2\right) - \mathsf{min}\left(\phi_1, \phi_2\right)\right) \cdot R\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{hypot}\left(\mathsf{max}\left(\phi_1, \phi_2\right), \cos \left(-0.5 \cdot \mathsf{min}\left(\phi_1, \phi_2\right)\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R\\
    
    
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if phi1 < -4.2999999999999998e92

      1. Initial program 60.0%

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

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

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

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

          \[\leadsto R \cdot \left(\phi_2 \cdot \left(1 + -1 \cdot \color{blue}{\frac{\phi_1}{\phi_2}}\right)\right) \]
        4. lower-/.f6425.7%

          \[\leadsto R \cdot \left(\phi_2 \cdot \left(1 + -1 \cdot \frac{\phi_1}{\color{blue}{\phi_2}}\right)\right) \]
      4. Applied rewrites25.7%

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

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

          \[\leadsto \color{blue}{\left(\phi_2 \cdot \left(1 + -1 \cdot \frac{\phi_1}{\phi_2}\right)\right) \cdot R} \]
        3. lower-*.f6425.7%

          \[\leadsto \color{blue}{\left(\phi_2 \cdot \left(1 + -1 \cdot \frac{\phi_1}{\phi_2}\right)\right) \cdot R} \]
      6. Applied rewrites28.2%

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

      if -4.2999999999999998e92 < phi1

      1. Initial program 60.0%

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

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

          \[\leadsto \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \cdot R} \]
        3. lower-*.f6460.0%

          \[\leadsto \color{blue}{\sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \cdot R} \]
      3. Applied rewrites96.0%

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

        \[\leadsto \mathsf{hypot}\left(\phi_2 - \phi_1, \cos \color{blue}{\left(\frac{-1}{2} \cdot \phi_1\right)} \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
      5. Step-by-step derivation
        1. lower-*.f6490.5%

          \[\leadsto \mathsf{hypot}\left(\phi_2 - \phi_1, \cos \left(-0.5 \cdot \color{blue}{\phi_1}\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
      6. Applied rewrites90.5%

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

        \[\leadsto \mathsf{hypot}\left(\color{blue}{\phi_2}, \cos \left(-0.5 \cdot \phi_1\right) \cdot \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
      8. Step-by-step derivation
        1. Applied rewrites70.4%

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

      Alternative 7: 67.1% accurate, 1.7× speedup?

      \[\begin{array}{l} \mathbf{if}\;\mathsf{max}\left(\lambda_1, \lambda_2\right) \leq 2.65 \cdot 10^{+113}:\\ \;\;\;\;\left(\mathsf{max}\left(\phi_1, \phi_2\right) - \mathsf{min}\left(\phi_1, \phi_2\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\left(\left|\cos \left(\left(\mathsf{min}\left(\phi_1, \phi_2\right) + \mathsf{max}\left(\phi_1, \phi_2\right)\right) \cdot 0.5\right)\right| \cdot \mathsf{max}\left(\lambda_1, \lambda_2\right)\right) \cdot R\\ \end{array} \]
      (FPCore (R lambda1 lambda2 phi1 phi2)
       :precision binary64
       (if (<= (fmax lambda1 lambda2) 2.65e+113)
         (* (- (fmax phi1 phi2) (fmin phi1 phi2)) R)
         (*
          (*
           (fabs (cos (* (+ (fmin phi1 phi2) (fmax phi1 phi2)) 0.5)))
           (fmax lambda1 lambda2))
          R)))
      double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
      	double tmp;
      	if (fmax(lambda1, lambda2) <= 2.65e+113) {
      		tmp = (fmax(phi1, phi2) - fmin(phi1, phi2)) * R;
      	} else {
      		tmp = (fabs(cos(((fmin(phi1, phi2) + fmax(phi1, phi2)) * 0.5))) * fmax(lambda1, lambda2)) * R;
      	}
      	return tmp;
      }
      
      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 (fmax(lambda1, lambda2) <= 2.65d+113) then
              tmp = (fmax(phi1, phi2) - fmin(phi1, phi2)) * r
          else
              tmp = (abs(cos(((fmin(phi1, phi2) + fmax(phi1, phi2)) * 0.5d0))) * fmax(lambda1, lambda2)) * r
          end if
          code = tmp
      end function
      
      public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
      	double tmp;
      	if (fmax(lambda1, lambda2) <= 2.65e+113) {
      		tmp = (fmax(phi1, phi2) - fmin(phi1, phi2)) * R;
      	} else {
      		tmp = (Math.abs(Math.cos(((fmin(phi1, phi2) + fmax(phi1, phi2)) * 0.5))) * fmax(lambda1, lambda2)) * R;
      	}
      	return tmp;
      }
      
      def code(R, lambda1, lambda2, phi1, phi2):
      	tmp = 0
      	if fmax(lambda1, lambda2) <= 2.65e+113:
      		tmp = (fmax(phi1, phi2) - fmin(phi1, phi2)) * R
      	else:
      		tmp = (math.fabs(math.cos(((fmin(phi1, phi2) + fmax(phi1, phi2)) * 0.5))) * fmax(lambda1, lambda2)) * R
      	return tmp
      
      function code(R, lambda1, lambda2, phi1, phi2)
      	tmp = 0.0
      	if (fmax(lambda1, lambda2) <= 2.65e+113)
      		tmp = Float64(Float64(fmax(phi1, phi2) - fmin(phi1, phi2)) * R);
      	else
      		tmp = Float64(Float64(abs(cos(Float64(Float64(fmin(phi1, phi2) + fmax(phi1, phi2)) * 0.5))) * fmax(lambda1, lambda2)) * R);
      	end
      	return tmp
      end
      
      function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
      	tmp = 0.0;
      	if (max(lambda1, lambda2) <= 2.65e+113)
      		tmp = (max(phi1, phi2) - min(phi1, phi2)) * R;
      	else
      		tmp = (abs(cos(((min(phi1, phi2) + max(phi1, phi2)) * 0.5))) * max(lambda1, lambda2)) * R;
      	end
      	tmp_2 = tmp;
      end
      
      code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[LessEqual[N[Max[lambda1, lambda2], $MachinePrecision], 2.65e+113], N[(N[(N[Max[phi1, phi2], $MachinePrecision] - N[Min[phi1, phi2], $MachinePrecision]), $MachinePrecision] * R), $MachinePrecision], N[(N[(N[Abs[N[Cos[N[(N[(N[Min[phi1, phi2], $MachinePrecision] + N[Max[phi1, phi2], $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision]], $MachinePrecision]], $MachinePrecision] * N[Max[lambda1, lambda2], $MachinePrecision]), $MachinePrecision] * R), $MachinePrecision]]
      
      \begin{array}{l}
      \mathbf{if}\;\mathsf{max}\left(\lambda_1, \lambda_2\right) \leq 2.65 \cdot 10^{+113}:\\
      \;\;\;\;\left(\mathsf{max}\left(\phi_1, \phi_2\right) - \mathsf{min}\left(\phi_1, \phi_2\right)\right) \cdot R\\
      
      \mathbf{else}:\\
      \;\;\;\;\left(\left|\cos \left(\left(\mathsf{min}\left(\phi_1, \phi_2\right) + \mathsf{max}\left(\phi_1, \phi_2\right)\right) \cdot 0.5\right)\right| \cdot \mathsf{max}\left(\lambda_1, \lambda_2\right)\right) \cdot R\\
      
      
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if lambda2 < 2.64999999999999984e113

        1. Initial program 60.0%

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

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

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

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

            \[\leadsto R \cdot \left(\phi_2 \cdot \left(1 + -1 \cdot \color{blue}{\frac{\phi_1}{\phi_2}}\right)\right) \]
          4. lower-/.f6425.7%

            \[\leadsto R \cdot \left(\phi_2 \cdot \left(1 + -1 \cdot \frac{\phi_1}{\color{blue}{\phi_2}}\right)\right) \]
        4. Applied rewrites25.7%

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

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

            \[\leadsto \color{blue}{\left(\phi_2 \cdot \left(1 + -1 \cdot \frac{\phi_1}{\phi_2}\right)\right) \cdot R} \]
          3. lower-*.f6425.7%

            \[\leadsto \color{blue}{\left(\phi_2 \cdot \left(1 + -1 \cdot \frac{\phi_1}{\phi_2}\right)\right) \cdot R} \]
        6. Applied rewrites28.2%

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

        if 2.64999999999999984e113 < lambda2

        1. Initial program 60.0%

          \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
        2. Taylor expanded in lambda2 around inf

          \[\leadsto R \cdot \color{blue}{\left(\lambda_2 \cdot \sqrt{{\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}}\right)} \]
        3. Step-by-step derivation
          1. lower-*.f64N/A

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

            \[\leadsto R \cdot \left(\lambda_2 \cdot \sqrt{{\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}}\right) \]
          3. lower-pow.f64N/A

            \[\leadsto R \cdot \left(\lambda_2 \cdot \sqrt{{\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}}\right) \]
          4. lower-cos.f64N/A

            \[\leadsto R \cdot \left(\lambda_2 \cdot \sqrt{{\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}}\right) \]
          5. lower-*.f64N/A

            \[\leadsto R \cdot \left(\lambda_2 \cdot \sqrt{{\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}}\right) \]
          6. lower-+.f6417.0%

            \[\leadsto R \cdot \left(\lambda_2 \cdot \sqrt{{\cos \left(0.5 \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}}\right) \]
        4. Applied rewrites17.0%

          \[\leadsto R \cdot \color{blue}{\left(\lambda_2 \cdot \sqrt{{\cos \left(0.5 \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}}\right)} \]
        5. Step-by-step derivation
          1. lift-*.f64N/A

            \[\leadsto \color{blue}{R \cdot \left(\lambda_2 \cdot \sqrt{{\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}}\right)} \]
          2. *-commutativeN/A

            \[\leadsto \color{blue}{\left(\lambda_2 \cdot \sqrt{{\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}}\right) \cdot R} \]
          3. lower-*.f6417.0%

            \[\leadsto \color{blue}{\left(\lambda_2 \cdot \sqrt{{\cos \left(0.5 \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}}\right) \cdot R} \]
        6. Applied rewrites17.0%

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

      Alternative 8: 64.8% accurate, 1.9× speedup?

      \[\begin{array}{l} \mathbf{if}\;\mathsf{max}\left(\lambda_1, \lambda_2\right) \leq 2.65 \cdot 10^{+113}:\\ \;\;\;\;\left(\mathsf{max}\left(\phi_1, \phi_2\right) - \mathsf{min}\left(\phi_1, \phi_2\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\left(\left|\cos \left(0.5 \cdot \mathsf{max}\left(\phi_1, \phi_2\right)\right)\right| \cdot \mathsf{max}\left(\lambda_1, \lambda_2\right)\right) \cdot R\\ \end{array} \]
      (FPCore (R lambda1 lambda2 phi1 phi2)
       :precision binary64
       (if (<= (fmax lambda1 lambda2) 2.65e+113)
         (* (- (fmax phi1 phi2) (fmin phi1 phi2)) R)
         (* (* (fabs (cos (* 0.5 (fmax phi1 phi2)))) (fmax lambda1 lambda2)) R)))
      double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
      	double tmp;
      	if (fmax(lambda1, lambda2) <= 2.65e+113) {
      		tmp = (fmax(phi1, phi2) - fmin(phi1, phi2)) * R;
      	} else {
      		tmp = (fabs(cos((0.5 * fmax(phi1, phi2)))) * fmax(lambda1, lambda2)) * R;
      	}
      	return tmp;
      }
      
      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 (fmax(lambda1, lambda2) <= 2.65d+113) then
              tmp = (fmax(phi1, phi2) - fmin(phi1, phi2)) * r
          else
              tmp = (abs(cos((0.5d0 * fmax(phi1, phi2)))) * fmax(lambda1, lambda2)) * r
          end if
          code = tmp
      end function
      
      public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
      	double tmp;
      	if (fmax(lambda1, lambda2) <= 2.65e+113) {
      		tmp = (fmax(phi1, phi2) - fmin(phi1, phi2)) * R;
      	} else {
      		tmp = (Math.abs(Math.cos((0.5 * fmax(phi1, phi2)))) * fmax(lambda1, lambda2)) * R;
      	}
      	return tmp;
      }
      
      def code(R, lambda1, lambda2, phi1, phi2):
      	tmp = 0
      	if fmax(lambda1, lambda2) <= 2.65e+113:
      		tmp = (fmax(phi1, phi2) - fmin(phi1, phi2)) * R
      	else:
      		tmp = (math.fabs(math.cos((0.5 * fmax(phi1, phi2)))) * fmax(lambda1, lambda2)) * R
      	return tmp
      
      function code(R, lambda1, lambda2, phi1, phi2)
      	tmp = 0.0
      	if (fmax(lambda1, lambda2) <= 2.65e+113)
      		tmp = Float64(Float64(fmax(phi1, phi2) - fmin(phi1, phi2)) * R);
      	else
      		tmp = Float64(Float64(abs(cos(Float64(0.5 * fmax(phi1, phi2)))) * fmax(lambda1, lambda2)) * R);
      	end
      	return tmp
      end
      
      function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
      	tmp = 0.0;
      	if (max(lambda1, lambda2) <= 2.65e+113)
      		tmp = (max(phi1, phi2) - min(phi1, phi2)) * R;
      	else
      		tmp = (abs(cos((0.5 * max(phi1, phi2)))) * max(lambda1, lambda2)) * R;
      	end
      	tmp_2 = tmp;
      end
      
      code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[LessEqual[N[Max[lambda1, lambda2], $MachinePrecision], 2.65e+113], N[(N[(N[Max[phi1, phi2], $MachinePrecision] - N[Min[phi1, phi2], $MachinePrecision]), $MachinePrecision] * R), $MachinePrecision], N[(N[(N[Abs[N[Cos[N[(0.5 * N[Max[phi1, phi2], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision] * N[Max[lambda1, lambda2], $MachinePrecision]), $MachinePrecision] * R), $MachinePrecision]]
      
      \begin{array}{l}
      \mathbf{if}\;\mathsf{max}\left(\lambda_1, \lambda_2\right) \leq 2.65 \cdot 10^{+113}:\\
      \;\;\;\;\left(\mathsf{max}\left(\phi_1, \phi_2\right) - \mathsf{min}\left(\phi_1, \phi_2\right)\right) \cdot R\\
      
      \mathbf{else}:\\
      \;\;\;\;\left(\left|\cos \left(0.5 \cdot \mathsf{max}\left(\phi_1, \phi_2\right)\right)\right| \cdot \mathsf{max}\left(\lambda_1, \lambda_2\right)\right) \cdot R\\
      
      
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if lambda2 < 2.64999999999999984e113

        1. Initial program 60.0%

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

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

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

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

            \[\leadsto R \cdot \left(\phi_2 \cdot \left(1 + -1 \cdot \color{blue}{\frac{\phi_1}{\phi_2}}\right)\right) \]
          4. lower-/.f6425.7%

            \[\leadsto R \cdot \left(\phi_2 \cdot \left(1 + -1 \cdot \frac{\phi_1}{\color{blue}{\phi_2}}\right)\right) \]
        4. Applied rewrites25.7%

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

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

            \[\leadsto \color{blue}{\left(\phi_2 \cdot \left(1 + -1 \cdot \frac{\phi_1}{\phi_2}\right)\right) \cdot R} \]
          3. lower-*.f6425.7%

            \[\leadsto \color{blue}{\left(\phi_2 \cdot \left(1 + -1 \cdot \frac{\phi_1}{\phi_2}\right)\right) \cdot R} \]
        6. Applied rewrites28.2%

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

        if 2.64999999999999984e113 < lambda2

        1. Initial program 60.0%

          \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
        2. Taylor expanded in lambda2 around inf

          \[\leadsto R \cdot \color{blue}{\left(\lambda_2 \cdot \sqrt{{\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}}\right)} \]
        3. Step-by-step derivation
          1. lower-*.f64N/A

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

            \[\leadsto R \cdot \left(\lambda_2 \cdot \sqrt{{\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}}\right) \]
          3. lower-pow.f64N/A

            \[\leadsto R \cdot \left(\lambda_2 \cdot \sqrt{{\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}}\right) \]
          4. lower-cos.f64N/A

            \[\leadsto R \cdot \left(\lambda_2 \cdot \sqrt{{\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}}\right) \]
          5. lower-*.f64N/A

            \[\leadsto R \cdot \left(\lambda_2 \cdot \sqrt{{\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}}\right) \]
          6. lower-+.f6417.0%

            \[\leadsto R \cdot \left(\lambda_2 \cdot \sqrt{{\cos \left(0.5 \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}}\right) \]
        4. Applied rewrites17.0%

          \[\leadsto R \cdot \color{blue}{\left(\lambda_2 \cdot \sqrt{{\cos \left(0.5 \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}}\right)} \]
        5. Taylor expanded in phi1 around 0

          \[\leadsto R \cdot \left(\lambda_2 \cdot \sqrt{{\cos \left(\frac{1}{2} \cdot \phi_2\right)}^{2}}\right) \]
        6. Step-by-step derivation
          1. lower-*.f6415.6%

            \[\leadsto R \cdot \left(\lambda_2 \cdot \sqrt{{\cos \left(0.5 \cdot \phi_2\right)}^{2}}\right) \]
        7. Applied rewrites15.6%

          \[\leadsto R \cdot \left(\lambda_2 \cdot \sqrt{{\cos \left(0.5 \cdot \phi_2\right)}^{2}}\right) \]
        8. Step-by-step derivation
          1. lift-*.f64N/A

            \[\leadsto \color{blue}{R \cdot \left(\lambda_2 \cdot \sqrt{{\cos \left(\frac{1}{2} \cdot \phi_2\right)}^{2}}\right)} \]
          2. *-commutativeN/A

            \[\leadsto \color{blue}{\left(\lambda_2 \cdot \sqrt{{\cos \left(\frac{1}{2} \cdot \phi_2\right)}^{2}}\right) \cdot R} \]
          3. lower-*.f6415.6%

            \[\leadsto \color{blue}{\left(\lambda_2 \cdot \sqrt{{\cos \left(0.5 \cdot \phi_2\right)}^{2}}\right) \cdot R} \]
        9. Applied rewrites15.6%

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

      Alternative 9: 56.8% accurate, 2.8× speedup?

      \[\begin{array}{l} \mathbf{if}\;\mathsf{min}\left(\lambda_1, \lambda_2\right) - \mathsf{max}\left(\lambda_1, \lambda_2\right) \leq -1800000:\\ \;\;\;\;\mathsf{max}\left(\phi_1, \phi_2\right) \cdot \left(R + -1 \cdot \frac{R \cdot \mathsf{min}\left(\phi_1, \phi_2\right)}{\mathsf{max}\left(\phi_1, \phi_2\right)}\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\mathsf{max}\left(\phi_1, \phi_2\right) - \mathsf{min}\left(\phi_1, \phi_2\right)\right) \cdot R\\ \end{array} \]
      (FPCore (R lambda1 lambda2 phi1 phi2)
       :precision binary64
       (if (<= (- (fmin lambda1 lambda2) (fmax lambda1 lambda2)) -1800000.0)
         (*
          (fmax phi1 phi2)
          (+ R (* -1.0 (/ (* R (fmin phi1 phi2)) (fmax phi1 phi2)))))
         (* (- (fmax phi1 phi2) (fmin phi1 phi2)) R)))
      double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
      	double tmp;
      	if ((fmin(lambda1, lambda2) - fmax(lambda1, lambda2)) <= -1800000.0) {
      		tmp = fmax(phi1, phi2) * (R + (-1.0 * ((R * fmin(phi1, phi2)) / fmax(phi1, phi2))));
      	} else {
      		tmp = (fmax(phi1, phi2) - fmin(phi1, phi2)) * R;
      	}
      	return tmp;
      }
      
      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 ((fmin(lambda1, lambda2) - fmax(lambda1, lambda2)) <= (-1800000.0d0)) then
              tmp = fmax(phi1, phi2) * (r + ((-1.0d0) * ((r * fmin(phi1, phi2)) / fmax(phi1, phi2))))
          else
              tmp = (fmax(phi1, phi2) - fmin(phi1, phi2)) * r
          end if
          code = tmp
      end function
      
      public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
      	double tmp;
      	if ((fmin(lambda1, lambda2) - fmax(lambda1, lambda2)) <= -1800000.0) {
      		tmp = fmax(phi1, phi2) * (R + (-1.0 * ((R * fmin(phi1, phi2)) / fmax(phi1, phi2))));
      	} else {
      		tmp = (fmax(phi1, phi2) - fmin(phi1, phi2)) * R;
      	}
      	return tmp;
      }
      
      def code(R, lambda1, lambda2, phi1, phi2):
      	tmp = 0
      	if (fmin(lambda1, lambda2) - fmax(lambda1, lambda2)) <= -1800000.0:
      		tmp = fmax(phi1, phi2) * (R + (-1.0 * ((R * fmin(phi1, phi2)) / fmax(phi1, phi2))))
      	else:
      		tmp = (fmax(phi1, phi2) - fmin(phi1, phi2)) * R
      	return tmp
      
      function code(R, lambda1, lambda2, phi1, phi2)
      	tmp = 0.0
      	if (Float64(fmin(lambda1, lambda2) - fmax(lambda1, lambda2)) <= -1800000.0)
      		tmp = Float64(fmax(phi1, phi2) * Float64(R + Float64(-1.0 * Float64(Float64(R * fmin(phi1, phi2)) / fmax(phi1, phi2)))));
      	else
      		tmp = Float64(Float64(fmax(phi1, phi2) - fmin(phi1, phi2)) * R);
      	end
      	return tmp
      end
      
      function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
      	tmp = 0.0;
      	if ((min(lambda1, lambda2) - max(lambda1, lambda2)) <= -1800000.0)
      		tmp = max(phi1, phi2) * (R + (-1.0 * ((R * min(phi1, phi2)) / max(phi1, phi2))));
      	else
      		tmp = (max(phi1, phi2) - min(phi1, phi2)) * R;
      	end
      	tmp_2 = tmp;
      end
      
      code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[LessEqual[N[(N[Min[lambda1, lambda2], $MachinePrecision] - N[Max[lambda1, lambda2], $MachinePrecision]), $MachinePrecision], -1800000.0], N[(N[Max[phi1, phi2], $MachinePrecision] * N[(R + N[(-1.0 * N[(N[(R * N[Min[phi1, phi2], $MachinePrecision]), $MachinePrecision] / N[Max[phi1, phi2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[Max[phi1, phi2], $MachinePrecision] - N[Min[phi1, phi2], $MachinePrecision]), $MachinePrecision] * R), $MachinePrecision]]
      
      \begin{array}{l}
      \mathbf{if}\;\mathsf{min}\left(\lambda_1, \lambda_2\right) - \mathsf{max}\left(\lambda_1, \lambda_2\right) \leq -1800000:\\
      \;\;\;\;\mathsf{max}\left(\phi_1, \phi_2\right) \cdot \left(R + -1 \cdot \frac{R \cdot \mathsf{min}\left(\phi_1, \phi_2\right)}{\mathsf{max}\left(\phi_1, \phi_2\right)}\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\left(\mathsf{max}\left(\phi_1, \phi_2\right) - \mathsf{min}\left(\phi_1, \phi_2\right)\right) \cdot R\\
      
      
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (-.f64 lambda1 lambda2) < -1.8e6

        1. Initial program 60.0%

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

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

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

            \[\leadsto \phi_2 \cdot \left(R + -1 \cdot \frac{R \cdot \phi_1}{\color{blue}{\phi_2}}\right) \]
          5. lower-*.f6427.5%

            \[\leadsto \phi_2 \cdot \left(R + -1 \cdot \frac{R \cdot \phi_1}{\phi_2}\right) \]
        4. Applied rewrites27.5%

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

        if -1.8e6 < (-.f64 lambda1 lambda2)

        1. Initial program 60.0%

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

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

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

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

            \[\leadsto R \cdot \left(\phi_2 \cdot \left(1 + -1 \cdot \color{blue}{\frac{\phi_1}{\phi_2}}\right)\right) \]
          4. lower-/.f6425.7%

            \[\leadsto R \cdot \left(\phi_2 \cdot \left(1 + -1 \cdot \frac{\phi_1}{\color{blue}{\phi_2}}\right)\right) \]
        4. Applied rewrites25.7%

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

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

            \[\leadsto \color{blue}{\left(\phi_2 \cdot \left(1 + -1 \cdot \frac{\phi_1}{\phi_2}\right)\right) \cdot R} \]
          3. lower-*.f6425.7%

            \[\leadsto \color{blue}{\left(\phi_2 \cdot \left(1 + -1 \cdot \frac{\phi_1}{\phi_2}\right)\right) \cdot R} \]
        6. Applied rewrites28.2%

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

      Alternative 10: 56.3% accurate, 8.4× speedup?

      \[\left(\mathsf{max}\left(\phi_1, \phi_2\right) - \mathsf{min}\left(\phi_1, \phi_2\right)\right) \cdot R \]
      (FPCore (R lambda1 lambda2 phi1 phi2)
       :precision binary64
       (* (- (fmax phi1 phi2) (fmin phi1 phi2)) R))
      double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
      	return (fmax(phi1, phi2) - fmin(phi1, phi2)) * R;
      }
      
      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 = (fmax(phi1, phi2) - fmin(phi1, phi2)) * r
      end function
      
      public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
      	return (fmax(phi1, phi2) - fmin(phi1, phi2)) * R;
      }
      
      def code(R, lambda1, lambda2, phi1, phi2):
      	return (fmax(phi1, phi2) - fmin(phi1, phi2)) * R
      
      function code(R, lambda1, lambda2, phi1, phi2)
      	return Float64(Float64(fmax(phi1, phi2) - fmin(phi1, phi2)) * R)
      end
      
      function tmp = code(R, lambda1, lambda2, phi1, phi2)
      	tmp = (max(phi1, phi2) - min(phi1, phi2)) * R;
      end
      
      code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(N[(N[Max[phi1, phi2], $MachinePrecision] - N[Min[phi1, phi2], $MachinePrecision]), $MachinePrecision] * R), $MachinePrecision]
      
      \left(\mathsf{max}\left(\phi_1, \phi_2\right) - \mathsf{min}\left(\phi_1, \phi_2\right)\right) \cdot R
      
      Derivation
      1. Initial program 60.0%

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

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

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

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

          \[\leadsto R \cdot \left(\phi_2 \cdot \left(1 + -1 \cdot \color{blue}{\frac{\phi_1}{\phi_2}}\right)\right) \]
        4. lower-/.f6425.7%

          \[\leadsto R \cdot \left(\phi_2 \cdot \left(1 + -1 \cdot \frac{\phi_1}{\color{blue}{\phi_2}}\right)\right) \]
      4. Applied rewrites25.7%

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

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

          \[\leadsto \color{blue}{\left(\phi_2 \cdot \left(1 + -1 \cdot \frac{\phi_1}{\phi_2}\right)\right) \cdot R} \]
        3. lower-*.f6425.7%

          \[\leadsto \color{blue}{\left(\phi_2 \cdot \left(1 + -1 \cdot \frac{\phi_1}{\phi_2}\right)\right) \cdot R} \]
      6. Applied rewrites28.2%

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

      Alternative 11: 30.9% accurate, 15.4× speedup?

      \[R \cdot \mathsf{max}\left(\phi_1, \phi_2\right) \]
      (FPCore (R lambda1 lambda2 phi1 phi2)
       :precision binary64
       (* R (fmax phi1 phi2)))
      double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
      	return R * fmax(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
          code = r * fmax(phi1, phi2)
      end function
      
      public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
      	return R * fmax(phi1, phi2);
      }
      
      def code(R, lambda1, lambda2, phi1, phi2):
      	return R * fmax(phi1, phi2)
      
      function code(R, lambda1, lambda2, phi1, phi2)
      	return Float64(R * fmax(phi1, phi2))
      end
      
      function tmp = code(R, lambda1, lambda2, phi1, phi2)
      	tmp = R * max(phi1, phi2);
      end
      
      code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(R * N[Max[phi1, phi2], $MachinePrecision]), $MachinePrecision]
      
      R \cdot \mathsf{max}\left(\phi_1, \phi_2\right)
      
      Derivation
      1. Initial program 60.0%

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

        \[\leadsto \color{blue}{R \cdot \phi_2} \]
      3. Step-by-step derivation
        1. lower-*.f6416.6%

          \[\leadsto R \cdot \color{blue}{\phi_2} \]
      4. Applied rewrites16.6%

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

      Alternative 12: 18.2% accurate, 27.0× speedup?

      \[R \cdot \phi_1 \]
      (FPCore (R lambda1 lambda2 phi1 phi2) :precision binary64 (* R phi1))
      double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
      	return R * phi1;
      }
      
      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
      
      public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
      	return R * phi1;
      }
      
      def code(R, lambda1, lambda2, phi1, phi2):
      	return R * phi1
      
      function code(R, lambda1, lambda2, phi1, phi2)
      	return Float64(R * phi1)
      end
      
      function tmp = code(R, lambda1, lambda2, phi1, phi2)
      	tmp = R * phi1;
      end
      
      code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(R * phi1), $MachinePrecision]
      
      R \cdot \phi_1
      
      Derivation
      1. Initial program 60.0%

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

        \[\leadsto \color{blue}{R \cdot \phi_1} \]
      3. Step-by-step derivation
        1. lower-*.f6418.2%

          \[\leadsto R \cdot \color{blue}{\phi_1} \]
      4. Applied rewrites18.2%

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

      Reproduce

      ?
      herbie shell --seed 2025188 
      (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))))))