Spherical law of cosines

Percentage Accurate: 74.2% → 94.4%
Time: 15.3s
Alternatives: 20
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \end{array} \]
(FPCore (R lambda1 lambda2 phi1 phi2)
 :precision binary64
 (*
  (acos
   (+
    (* (sin phi1) (sin phi2))
    (* (* (cos phi1) (cos phi2)) (cos (- lambda1 lambda2)))))
  R))
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	return acos(((sin(phi1) * sin(phi2)) + ((cos(phi1) * cos(phi2)) * cos((lambda1 - lambda2))))) * 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 = acos(((sin(phi1) * sin(phi2)) + ((cos(phi1) * cos(phi2)) * cos((lambda1 - lambda2))))) * r
end function
public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	return Math.acos(((Math.sin(phi1) * Math.sin(phi2)) + ((Math.cos(phi1) * Math.cos(phi2)) * Math.cos((lambda1 - lambda2))))) * R;
}
def code(R, lambda1, lambda2, phi1, phi2):
	return math.acos(((math.sin(phi1) * math.sin(phi2)) + ((math.cos(phi1) * math.cos(phi2)) * math.cos((lambda1 - lambda2))))) * R
function code(R, lambda1, lambda2, phi1, phi2)
	return Float64(acos(Float64(Float64(sin(phi1) * sin(phi2)) + Float64(Float64(cos(phi1) * cos(phi2)) * cos(Float64(lambda1 - lambda2))))) * R)
end
function tmp = code(R, lambda1, lambda2, phi1, phi2)
	tmp = acos(((sin(phi1) * sin(phi2)) + ((cos(phi1) * cos(phi2)) * cos((lambda1 - lambda2))))) * R;
end
code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(N[ArcCos[N[(N[(N[Sin[phi1], $MachinePrecision] * N[Sin[phi2], $MachinePrecision]), $MachinePrecision] + N[(N[(N[Cos[phi1], $MachinePrecision] * N[Cos[phi2], $MachinePrecision]), $MachinePrecision] * N[Cos[N[(lambda1 - lambda2), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]
\begin{array}{l}

\\
\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 20 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: 74.2% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \end{array} \]
(FPCore (R lambda1 lambda2 phi1 phi2)
 :precision binary64
 (*
  (acos
   (+
    (* (sin phi1) (sin phi2))
    (* (* (cos phi1) (cos phi2)) (cos (- lambda1 lambda2)))))
  R))
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	return acos(((sin(phi1) * sin(phi2)) + ((cos(phi1) * cos(phi2)) * cos((lambda1 - lambda2))))) * 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 = acos(((sin(phi1) * sin(phi2)) + ((cos(phi1) * cos(phi2)) * cos((lambda1 - lambda2))))) * r
end function
public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	return Math.acos(((Math.sin(phi1) * Math.sin(phi2)) + ((Math.cos(phi1) * Math.cos(phi2)) * Math.cos((lambda1 - lambda2))))) * R;
}
def code(R, lambda1, lambda2, phi1, phi2):
	return math.acos(((math.sin(phi1) * math.sin(phi2)) + ((math.cos(phi1) * math.cos(phi2)) * math.cos((lambda1 - lambda2))))) * R
function code(R, lambda1, lambda2, phi1, phi2)
	return Float64(acos(Float64(Float64(sin(phi1) * sin(phi2)) + Float64(Float64(cos(phi1) * cos(phi2)) * cos(Float64(lambda1 - lambda2))))) * R)
end
function tmp = code(R, lambda1, lambda2, phi1, phi2)
	tmp = acos(((sin(phi1) * sin(phi2)) + ((cos(phi1) * cos(phi2)) * cos((lambda1 - lambda2))))) * R;
end
code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(N[ArcCos[N[(N[(N[Sin[phi1], $MachinePrecision] * N[Sin[phi2], $MachinePrecision]), $MachinePrecision] + N[(N[(N[Cos[phi1], $MachinePrecision] * N[Cos[phi2], $MachinePrecision]), $MachinePrecision] * N[Cos[N[(lambda1 - lambda2), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]
\begin{array}{l}

\\
\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R
\end{array}

Alternative 1: 94.4% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \cos \lambda_1\right)\right) \cdot R \end{array} \]
(FPCore (R lambda1 lambda2 phi1 phi2)
 :precision binary64
 (*
  (acos
   (+
    (* (sin phi1) (sin phi2))
    (*
     (* (cos phi1) (cos phi2))
     (fma (sin lambda2) (sin lambda1) (* (cos lambda2) (cos lambda1))))))
  R))
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	return acos(((sin(phi1) * sin(phi2)) + ((cos(phi1) * cos(phi2)) * fma(sin(lambda2), sin(lambda1), (cos(lambda2) * cos(lambda1)))))) * R;
}
function code(R, lambda1, lambda2, phi1, phi2)
	return Float64(acos(Float64(Float64(sin(phi1) * sin(phi2)) + Float64(Float64(cos(phi1) * cos(phi2)) * fma(sin(lambda2), sin(lambda1), Float64(cos(lambda2) * cos(lambda1)))))) * R)
end
code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(N[ArcCos[N[(N[(N[Sin[phi1], $MachinePrecision] * N[Sin[phi2], $MachinePrecision]), $MachinePrecision] + N[(N[(N[Cos[phi1], $MachinePrecision] * N[Cos[phi2], $MachinePrecision]), $MachinePrecision] * N[(N[Sin[lambda2], $MachinePrecision] * N[Sin[lambda1], $MachinePrecision] + N[(N[Cos[lambda2], $MachinePrecision] * N[Cos[lambda1], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]
\begin{array}{l}

\\
\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \cos \lambda_1\right)\right) \cdot R
\end{array}
Derivation
  1. Initial program 73.6%

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

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

      \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \color{blue}{\left(\lambda_1 - \lambda_2\right)}\right) \cdot R \]
    3. cos-diffN/A

      \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\left(\cos \lambda_1 \cdot \cos \lambda_2 + \sin \lambda_1 \cdot \sin \lambda_2\right)}\right) \cdot R \]
    4. +-commutativeN/A

      \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\left(\sin \lambda_1 \cdot \sin \lambda_2 + \cos \lambda_1 \cdot \cos \lambda_2\right)}\right) \cdot R \]
    5. *-commutativeN/A

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

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

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

      \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \color{blue}{\sin \lambda_1}, \cos \lambda_1 \cdot \cos \lambda_2\right)\right) \cdot R \]
    9. *-commutativeN/A

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

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

      \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \color{blue}{\cos \lambda_2} \cdot \cos \lambda_1\right)\right) \cdot R \]
    12. lower-cos.f6493.7

      \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \color{blue}{\cos \lambda_1}\right)\right) \cdot R \]
  4. Applied rewrites93.7%

    \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \cos \lambda_1\right)}\right) \cdot R \]
  5. Add Preprocessing

Alternative 2: 94.4% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \cos^{-1} \left(\mathsf{fma}\left(\mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_2, \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right) \cdot R \end{array} \]
(FPCore (R lambda1 lambda2 phi1 phi2)
 :precision binary64
 (*
  (acos
   (fma
    (*
     (fma (cos lambda1) (cos lambda2) (* (sin lambda1) (sin lambda2)))
     (cos phi2))
    (cos phi1)
    (* (sin phi2) (sin phi1))))
  R))
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	return acos(fma((fma(cos(lambda1), cos(lambda2), (sin(lambda1) * sin(lambda2))) * cos(phi2)), cos(phi1), (sin(phi2) * sin(phi1)))) * R;
}
function code(R, lambda1, lambda2, phi1, phi2)
	return Float64(acos(fma(Float64(fma(cos(lambda1), cos(lambda2), Float64(sin(lambda1) * sin(lambda2))) * cos(phi2)), cos(phi1), Float64(sin(phi2) * sin(phi1)))) * R)
end
code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(N[ArcCos[N[(N[(N[(N[Cos[lambda1], $MachinePrecision] * N[Cos[lambda2], $MachinePrecision] + N[(N[Sin[lambda1], $MachinePrecision] * N[Sin[lambda2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Cos[phi2], $MachinePrecision]), $MachinePrecision] * N[Cos[phi1], $MachinePrecision] + N[(N[Sin[phi2], $MachinePrecision] * N[Sin[phi1], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]
\begin{array}{l}

\\
\cos^{-1} \left(\mathsf{fma}\left(\mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_2, \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right) \cdot R
\end{array}
Derivation
  1. Initial program 73.6%

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

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

      \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \color{blue}{\left(\lambda_1 - \lambda_2\right)}\right) \cdot R \]
    3. cos-diffN/A

      \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\left(\cos \lambda_1 \cdot \cos \lambda_2 + \sin \lambda_1 \cdot \sin \lambda_2\right)}\right) \cdot R \]
    4. +-commutativeN/A

      \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\left(\sin \lambda_1 \cdot \sin \lambda_2 + \cos \lambda_1 \cdot \cos \lambda_2\right)}\right) \cdot R \]
    5. *-commutativeN/A

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

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

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

      \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \color{blue}{\sin \lambda_1}, \cos \lambda_1 \cdot \cos \lambda_2\right)\right) \cdot R \]
    9. *-commutativeN/A

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

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

      \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \color{blue}{\cos \lambda_2} \cdot \cos \lambda_1\right)\right) \cdot R \]
    12. lower-cos.f6493.7

      \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \color{blue}{\cos \lambda_1}\right)\right) \cdot R \]
  4. Applied rewrites93.7%

    \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \cos \lambda_1\right)}\right) \cdot R \]
  5. Taylor expanded in lambda1 around inf

    \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \left(\cos \phi_2 \cdot \left(\cos \lambda_1 \cdot \cos \lambda_2 + \sin \lambda_1 \cdot \sin \lambda_2\right)\right) + \sin \phi_1 \cdot \sin \phi_2\right)} \cdot R \]
  6. Step-by-step derivation
    1. Applied rewrites93.7%

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

    Alternative 3: 83.9% accurate, 0.7× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\phi_2 \leq -3.6 \cdot 10^{-6} \lor \neg \left(\phi_2 \leq 3.3 \cdot 10^{-11}\right):\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_1\right) \cdot R\\ \end{array} \end{array} \]
    (FPCore (R lambda1 lambda2 phi1 phi2)
     :precision binary64
     (if (or (<= phi2 -3.6e-6) (not (<= phi2 3.3e-11)))
       (*
        (acos
         (fma
          (sin phi2)
          (sin phi1)
          (* (* (cos (- lambda2 lambda1)) (cos phi1)) (cos phi2))))
        R)
       (*
        (acos
         (+
          (* (sin phi1) (sin phi2))
          (*
           (fma (cos lambda1) (cos lambda2) (* (sin lambda1) (sin lambda2)))
           (cos phi1))))
        R)))
    double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
    	double tmp;
    	if ((phi2 <= -3.6e-6) || !(phi2 <= 3.3e-11)) {
    		tmp = acos(fma(sin(phi2), sin(phi1), ((cos((lambda2 - lambda1)) * cos(phi1)) * cos(phi2)))) * R;
    	} else {
    		tmp = acos(((sin(phi1) * sin(phi2)) + (fma(cos(lambda1), cos(lambda2), (sin(lambda1) * sin(lambda2))) * cos(phi1)))) * R;
    	}
    	return tmp;
    }
    
    function code(R, lambda1, lambda2, phi1, phi2)
    	tmp = 0.0
    	if ((phi2 <= -3.6e-6) || !(phi2 <= 3.3e-11))
    		tmp = Float64(acos(fma(sin(phi2), sin(phi1), Float64(Float64(cos(Float64(lambda2 - lambda1)) * cos(phi1)) * cos(phi2)))) * R);
    	else
    		tmp = Float64(acos(Float64(Float64(sin(phi1) * sin(phi2)) + Float64(fma(cos(lambda1), cos(lambda2), Float64(sin(lambda1) * sin(lambda2))) * cos(phi1)))) * R);
    	end
    	return tmp
    end
    
    code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[Or[LessEqual[phi2, -3.6e-6], N[Not[LessEqual[phi2, 3.3e-11]], $MachinePrecision]], N[(N[ArcCos[N[(N[Sin[phi2], $MachinePrecision] * N[Sin[phi1], $MachinePrecision] + N[(N[(N[Cos[N[(lambda2 - lambda1), $MachinePrecision]], $MachinePrecision] * N[Cos[phi1], $MachinePrecision]), $MachinePrecision] * N[Cos[phi2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], N[(N[ArcCos[N[(N[(N[Sin[phi1], $MachinePrecision] * N[Sin[phi2], $MachinePrecision]), $MachinePrecision] + N[(N[(N[Cos[lambda1], $MachinePrecision] * N[Cos[lambda2], $MachinePrecision] + N[(N[Sin[lambda1], $MachinePrecision] * N[Sin[lambda2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Cos[phi1], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;\phi_2 \leq -3.6 \cdot 10^{-6} \lor \neg \left(\phi_2 \leq 3.3 \cdot 10^{-11}\right):\\
    \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R\\
    
    \mathbf{else}:\\
    \;\;\;\;\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_1\right) \cdot R\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if phi2 < -3.59999999999999984e-6 or 3.3000000000000002e-11 < phi2

      1. Initial program 81.0%

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

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

          \[\leadsto \cos^{-1} \left(\color{blue}{\sin \phi_1 \cdot \sin \phi_2} + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
        3. *-commutativeN/A

          \[\leadsto \cos^{-1} \left(\color{blue}{\sin \phi_2 \cdot \sin \phi_1} + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
        4. lower-fma.f6481.1

          \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)\right)} \cdot R \]
        5. lift-*.f64N/A

          \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)}\right)\right) \cdot R \]
        6. *-commutativeN/A

          \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\cos \left(\lambda_1 - \lambda_2\right) \cdot \left(\cos \phi_1 \cdot \cos \phi_2\right)}\right)\right) \cdot R \]
        7. lift-*.f64N/A

          \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \cos \left(\lambda_1 - \lambda_2\right) \cdot \color{blue}{\left(\cos \phi_1 \cdot \cos \phi_2\right)}\right)\right) \cdot R \]
        8. associate-*r*N/A

          \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\left(\cos \left(\lambda_1 - \lambda_2\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2}\right)\right) \cdot R \]
        9. lower-*.f64N/A

          \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\left(\cos \left(\lambda_1 - \lambda_2\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2}\right)\right) \cdot R \]
        10. lower-*.f6481.1

          \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\left(\cos \left(\lambda_1 - \lambda_2\right) \cdot \cos \phi_1\right)} \cdot \cos \phi_2\right)\right) \cdot R \]
        11. lift-cos.f64N/A

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

          \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \color{blue}{\left(\lambda_1 - \lambda_2\right)} \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
        13. cos-diffN/A

          \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\color{blue}{\left(\cos \lambda_1 \cdot \cos \lambda_2 + \sin \lambda_1 \cdot \sin \lambda_2\right)} \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
        14. *-commutativeN/A

          \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\left(\color{blue}{\cos \lambda_2 \cdot \cos \lambda_1} + \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
        15. *-commutativeN/A

          \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\left(\cos \lambda_2 \cdot \cos \lambda_1 + \color{blue}{\sin \lambda_2 \cdot \sin \lambda_1}\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
        16. cos-diff-revN/A

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

          \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\color{blue}{\cos \left(\lambda_2 - \lambda_1\right)} \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
        18. lower--.f6481.1

          \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \color{blue}{\left(\lambda_2 - \lambda_1\right)} \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
      4. Applied rewrites81.1%

        \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right)} \cdot R \]

      if -3.59999999999999984e-6 < phi2 < 3.3000000000000002e-11

      1. Initial program 66.3%

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

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

          \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \color{blue}{\left(\lambda_1 - \lambda_2\right)}\right) \cdot R \]
        3. cos-diffN/A

          \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\left(\cos \lambda_1 \cdot \cos \lambda_2 + \sin \lambda_1 \cdot \sin \lambda_2\right)}\right) \cdot R \]
        4. +-commutativeN/A

          \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\left(\sin \lambda_1 \cdot \sin \lambda_2 + \cos \lambda_1 \cdot \cos \lambda_2\right)}\right) \cdot R \]
        5. *-commutativeN/A

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

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

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

          \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \color{blue}{\sin \lambda_1}, \cos \lambda_1 \cdot \cos \lambda_2\right)\right) \cdot R \]
        9. *-commutativeN/A

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

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

          \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \color{blue}{\cos \lambda_2} \cdot \cos \lambda_1\right)\right) \cdot R \]
        12. lower-cos.f6488.8

          \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \color{blue}{\cos \lambda_1}\right)\right) \cdot R \]
      4. Applied rewrites88.8%

        \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \cos \lambda_1\right)}\right) \cdot R \]
      5. Taylor expanded in phi2 around 0

        \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \color{blue}{\cos \phi_1 \cdot \left(\cos \lambda_1 \cdot \cos \lambda_2 + \sin \lambda_1 \cdot \sin \lambda_2\right)}\right) \cdot R \]
      6. Step-by-step derivation
        1. Applied rewrites88.7%

          \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \color{blue}{\mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_1}\right) \cdot R \]
      7. Recombined 2 regimes into one program.
      8. Final simplification84.9%

        \[\leadsto \begin{array}{l} \mathbf{if}\;\phi_2 \leq -3.6 \cdot 10^{-6} \lor \neg \left(\phi_2 \leq 3.3 \cdot 10^{-11}\right):\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_1\right) \cdot R\\ \end{array} \]
      9. Add Preprocessing

      Alternative 4: 83.9% accurate, 0.8× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\phi_2 \leq -3.6 \cdot 10^{-6} \lor \neg \left(\phi_2 \leq 3.3 \cdot 10^{-11}\right):\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right), \cos \phi_1, \sin \phi_1 \cdot \phi_2\right)\right) \cdot R\\ \end{array} \end{array} \]
      (FPCore (R lambda1 lambda2 phi1 phi2)
       :precision binary64
       (if (or (<= phi2 -3.6e-6) (not (<= phi2 3.3e-11)))
         (*
          (acos
           (fma
            (sin phi2)
            (sin phi1)
            (* (* (cos (- lambda2 lambda1)) (cos phi1)) (cos phi2))))
          R)
         (*
          (acos
           (fma
            (fma (cos lambda1) (cos lambda2) (* (sin lambda1) (sin lambda2)))
            (cos phi1)
            (* (sin phi1) phi2)))
          R)))
      double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
      	double tmp;
      	if ((phi2 <= -3.6e-6) || !(phi2 <= 3.3e-11)) {
      		tmp = acos(fma(sin(phi2), sin(phi1), ((cos((lambda2 - lambda1)) * cos(phi1)) * cos(phi2)))) * R;
      	} else {
      		tmp = acos(fma(fma(cos(lambda1), cos(lambda2), (sin(lambda1) * sin(lambda2))), cos(phi1), (sin(phi1) * phi2))) * R;
      	}
      	return tmp;
      }
      
      function code(R, lambda1, lambda2, phi1, phi2)
      	tmp = 0.0
      	if ((phi2 <= -3.6e-6) || !(phi2 <= 3.3e-11))
      		tmp = Float64(acos(fma(sin(phi2), sin(phi1), Float64(Float64(cos(Float64(lambda2 - lambda1)) * cos(phi1)) * cos(phi2)))) * R);
      	else
      		tmp = Float64(acos(fma(fma(cos(lambda1), cos(lambda2), Float64(sin(lambda1) * sin(lambda2))), cos(phi1), Float64(sin(phi1) * phi2))) * R);
      	end
      	return tmp
      end
      
      code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[Or[LessEqual[phi2, -3.6e-6], N[Not[LessEqual[phi2, 3.3e-11]], $MachinePrecision]], N[(N[ArcCos[N[(N[Sin[phi2], $MachinePrecision] * N[Sin[phi1], $MachinePrecision] + N[(N[(N[Cos[N[(lambda2 - lambda1), $MachinePrecision]], $MachinePrecision] * N[Cos[phi1], $MachinePrecision]), $MachinePrecision] * N[Cos[phi2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], N[(N[ArcCos[N[(N[(N[Cos[lambda1], $MachinePrecision] * N[Cos[lambda2], $MachinePrecision] + N[(N[Sin[lambda1], $MachinePrecision] * N[Sin[lambda2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Cos[phi1], $MachinePrecision] + N[(N[Sin[phi1], $MachinePrecision] * phi2), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;\phi_2 \leq -3.6 \cdot 10^{-6} \lor \neg \left(\phi_2 \leq 3.3 \cdot 10^{-11}\right):\\
      \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R\\
      
      \mathbf{else}:\\
      \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right), \cos \phi_1, \sin \phi_1 \cdot \phi_2\right)\right) \cdot R\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if phi2 < -3.59999999999999984e-6 or 3.3000000000000002e-11 < phi2

        1. Initial program 81.0%

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

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

            \[\leadsto \cos^{-1} \left(\color{blue}{\sin \phi_1 \cdot \sin \phi_2} + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
          3. *-commutativeN/A

            \[\leadsto \cos^{-1} \left(\color{blue}{\sin \phi_2 \cdot \sin \phi_1} + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
          4. lower-fma.f6481.1

            \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)\right)} \cdot R \]
          5. lift-*.f64N/A

            \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)}\right)\right) \cdot R \]
          6. *-commutativeN/A

            \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\cos \left(\lambda_1 - \lambda_2\right) \cdot \left(\cos \phi_1 \cdot \cos \phi_2\right)}\right)\right) \cdot R \]
          7. lift-*.f64N/A

            \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \cos \left(\lambda_1 - \lambda_2\right) \cdot \color{blue}{\left(\cos \phi_1 \cdot \cos \phi_2\right)}\right)\right) \cdot R \]
          8. associate-*r*N/A

            \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\left(\cos \left(\lambda_1 - \lambda_2\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2}\right)\right) \cdot R \]
          9. lower-*.f64N/A

            \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\left(\cos \left(\lambda_1 - \lambda_2\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2}\right)\right) \cdot R \]
          10. lower-*.f6481.1

            \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\left(\cos \left(\lambda_1 - \lambda_2\right) \cdot \cos \phi_1\right)} \cdot \cos \phi_2\right)\right) \cdot R \]
          11. lift-cos.f64N/A

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

            \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \color{blue}{\left(\lambda_1 - \lambda_2\right)} \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
          13. cos-diffN/A

            \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\color{blue}{\left(\cos \lambda_1 \cdot \cos \lambda_2 + \sin \lambda_1 \cdot \sin \lambda_2\right)} \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
          14. *-commutativeN/A

            \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\left(\color{blue}{\cos \lambda_2 \cdot \cos \lambda_1} + \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
          15. *-commutativeN/A

            \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\left(\cos \lambda_2 \cdot \cos \lambda_1 + \color{blue}{\sin \lambda_2 \cdot \sin \lambda_1}\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
          16. cos-diff-revN/A

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

            \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\color{blue}{\cos \left(\lambda_2 - \lambda_1\right)} \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
          18. lower--.f6481.1

            \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \color{blue}{\left(\lambda_2 - \lambda_1\right)} \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
        4. Applied rewrites81.1%

          \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right)} \cdot R \]

        if -3.59999999999999984e-6 < phi2 < 3.3000000000000002e-11

        1. Initial program 66.3%

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

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

            \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \color{blue}{\left(\lambda_1 - \lambda_2\right)}\right) \cdot R \]
          3. cos-diffN/A

            \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\left(\cos \lambda_1 \cdot \cos \lambda_2 + \sin \lambda_1 \cdot \sin \lambda_2\right)}\right) \cdot R \]
          4. +-commutativeN/A

            \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\left(\sin \lambda_1 \cdot \sin \lambda_2 + \cos \lambda_1 \cdot \cos \lambda_2\right)}\right) \cdot R \]
          5. *-commutativeN/A

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

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

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

            \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \color{blue}{\sin \lambda_1}, \cos \lambda_1 \cdot \cos \lambda_2\right)\right) \cdot R \]
          9. *-commutativeN/A

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

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

            \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \color{blue}{\cos \lambda_2} \cdot \cos \lambda_1\right)\right) \cdot R \]
          12. lower-cos.f6488.8

            \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \color{blue}{\cos \lambda_1}\right)\right) \cdot R \]
        4. Applied rewrites88.8%

          \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \cos \lambda_1\right)}\right) \cdot R \]
        5. Taylor expanded in phi2 around 0

          \[\leadsto \cos^{-1} \color{blue}{\left(\phi_2 \cdot \sin \phi_1 + \cos \phi_1 \cdot \left(\cos \lambda_1 \cdot \cos \lambda_2 + \sin \lambda_1 \cdot \sin \lambda_2\right)\right)} \cdot R \]
        6. Step-by-step derivation
          1. Applied rewrites88.7%

            \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right), \cos \phi_1, \sin \phi_1 \cdot \phi_2\right)\right)} \cdot R \]
        7. Recombined 2 regimes into one program.
        8. Final simplification84.9%

          \[\leadsto \begin{array}{l} \mathbf{if}\;\phi_2 \leq -3.6 \cdot 10^{-6} \lor \neg \left(\phi_2 \leq 3.3 \cdot 10^{-11}\right):\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right), \cos \phi_1, \sin \phi_1 \cdot \phi_2\right)\right) \cdot R\\ \end{array} \]
        9. Add Preprocessing

        Alternative 5: 83.8% accurate, 0.8× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\phi_2 \leq -3 \cdot 10^{-8} \lor \neg \left(\phi_2 \leq 2.65 \cdot 10^{-11}\right):\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \lambda_1 \cdot \sin \lambda_2, \cos \phi_1, \left(\cos \lambda_1 \cdot \cos \lambda_2\right) \cdot \cos \phi_1\right)\right) \cdot R\\ \end{array} \end{array} \]
        (FPCore (R lambda1 lambda2 phi1 phi2)
         :precision binary64
         (if (or (<= phi2 -3e-8) (not (<= phi2 2.65e-11)))
           (*
            (acos
             (fma
              (sin phi2)
              (sin phi1)
              (* (* (cos (- lambda2 lambda1)) (cos phi1)) (cos phi2))))
            R)
           (*
            (acos
             (fma
              (* (sin lambda1) (sin lambda2))
              (cos phi1)
              (* (* (cos lambda1) (cos lambda2)) (cos phi1))))
            R)))
        double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
        	double tmp;
        	if ((phi2 <= -3e-8) || !(phi2 <= 2.65e-11)) {
        		tmp = acos(fma(sin(phi2), sin(phi1), ((cos((lambda2 - lambda1)) * cos(phi1)) * cos(phi2)))) * R;
        	} else {
        		tmp = acos(fma((sin(lambda1) * sin(lambda2)), cos(phi1), ((cos(lambda1) * cos(lambda2)) * cos(phi1)))) * R;
        	}
        	return tmp;
        }
        
        function code(R, lambda1, lambda2, phi1, phi2)
        	tmp = 0.0
        	if ((phi2 <= -3e-8) || !(phi2 <= 2.65e-11))
        		tmp = Float64(acos(fma(sin(phi2), sin(phi1), Float64(Float64(cos(Float64(lambda2 - lambda1)) * cos(phi1)) * cos(phi2)))) * R);
        	else
        		tmp = Float64(acos(fma(Float64(sin(lambda1) * sin(lambda2)), cos(phi1), Float64(Float64(cos(lambda1) * cos(lambda2)) * cos(phi1)))) * R);
        	end
        	return tmp
        end
        
        code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[Or[LessEqual[phi2, -3e-8], N[Not[LessEqual[phi2, 2.65e-11]], $MachinePrecision]], N[(N[ArcCos[N[(N[Sin[phi2], $MachinePrecision] * N[Sin[phi1], $MachinePrecision] + N[(N[(N[Cos[N[(lambda2 - lambda1), $MachinePrecision]], $MachinePrecision] * N[Cos[phi1], $MachinePrecision]), $MachinePrecision] * N[Cos[phi2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], N[(N[ArcCos[N[(N[(N[Sin[lambda1], $MachinePrecision] * N[Sin[lambda2], $MachinePrecision]), $MachinePrecision] * N[Cos[phi1], $MachinePrecision] + N[(N[(N[Cos[lambda1], $MachinePrecision] * N[Cos[lambda2], $MachinePrecision]), $MachinePrecision] * N[Cos[phi1], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;\phi_2 \leq -3 \cdot 10^{-8} \lor \neg \left(\phi_2 \leq 2.65 \cdot 10^{-11}\right):\\
        \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R\\
        
        \mathbf{else}:\\
        \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \lambda_1 \cdot \sin \lambda_2, \cos \phi_1, \left(\cos \lambda_1 \cdot \cos \lambda_2\right) \cdot \cos \phi_1\right)\right) \cdot R\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if phi2 < -2.99999999999999973e-8 or 2.6499999999999999e-11 < phi2

          1. Initial program 81.0%

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

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

              \[\leadsto \cos^{-1} \left(\color{blue}{\sin \phi_1 \cdot \sin \phi_2} + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
            3. *-commutativeN/A

              \[\leadsto \cos^{-1} \left(\color{blue}{\sin \phi_2 \cdot \sin \phi_1} + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
            4. lower-fma.f6481.1

              \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)\right)} \cdot R \]
            5. lift-*.f64N/A

              \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)}\right)\right) \cdot R \]
            6. *-commutativeN/A

              \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\cos \left(\lambda_1 - \lambda_2\right) \cdot \left(\cos \phi_1 \cdot \cos \phi_2\right)}\right)\right) \cdot R \]
            7. lift-*.f64N/A

              \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \cos \left(\lambda_1 - \lambda_2\right) \cdot \color{blue}{\left(\cos \phi_1 \cdot \cos \phi_2\right)}\right)\right) \cdot R \]
            8. associate-*r*N/A

              \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\left(\cos \left(\lambda_1 - \lambda_2\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2}\right)\right) \cdot R \]
            9. lower-*.f64N/A

              \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\left(\cos \left(\lambda_1 - \lambda_2\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2}\right)\right) \cdot R \]
            10. lower-*.f6481.1

              \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\left(\cos \left(\lambda_1 - \lambda_2\right) \cdot \cos \phi_1\right)} \cdot \cos \phi_2\right)\right) \cdot R \]
            11. lift-cos.f64N/A

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

              \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \color{blue}{\left(\lambda_1 - \lambda_2\right)} \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
            13. cos-diffN/A

              \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\color{blue}{\left(\cos \lambda_1 \cdot \cos \lambda_2 + \sin \lambda_1 \cdot \sin \lambda_2\right)} \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
            14. *-commutativeN/A

              \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\left(\color{blue}{\cos \lambda_2 \cdot \cos \lambda_1} + \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
            15. *-commutativeN/A

              \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\left(\cos \lambda_2 \cdot \cos \lambda_1 + \color{blue}{\sin \lambda_2 \cdot \sin \lambda_1}\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
            16. cos-diff-revN/A

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

              \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\color{blue}{\cos \left(\lambda_2 - \lambda_1\right)} \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
            18. lower--.f6481.1

              \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \color{blue}{\left(\lambda_2 - \lambda_1\right)} \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
          4. Applied rewrites81.1%

            \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right)} \cdot R \]

          if -2.99999999999999973e-8 < phi2 < 2.6499999999999999e-11

          1. Initial program 66.3%

            \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
          2. Add Preprocessing
          3. Taylor expanded in phi2 around 0

            \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)} \cdot R \]
          4. Step-by-step derivation
            1. Applied rewrites66.2%

              \[\leadsto \cos^{-1} \color{blue}{\left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right)} \cdot R \]
            2. Step-by-step derivation
              1. Applied rewrites88.5%

                \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \lambda_1 \cdot \sin \lambda_2, \color{blue}{\cos \phi_1}, \left(\cos \lambda_1 \cdot \cos \lambda_2\right) \cdot \cos \phi_1\right)\right) \cdot R \]
            3. Recombined 2 regimes into one program.
            4. Final simplification84.8%

              \[\leadsto \begin{array}{l} \mathbf{if}\;\phi_2 \leq -3 \cdot 10^{-8} \lor \neg \left(\phi_2 \leq 2.65 \cdot 10^{-11}\right):\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \lambda_1 \cdot \sin \lambda_2, \cos \phi_1, \left(\cos \lambda_1 \cdot \cos \lambda_2\right) \cdot \cos \phi_1\right)\right) \cdot R\\ \end{array} \]
            5. Add Preprocessing

            Alternative 6: 73.2% accurate, 1.0× speedup?

            \[\begin{array}{l} \\ \begin{array}{l} t_0 := \mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right)\\ \mathbf{if}\;\lambda_2 \leq -2.2 \cdot 10^{+133}:\\ \;\;\;\;\cos^{-1} \left(t\_0 \cdot \cos \phi_1\right) \cdot R\\ \mathbf{elif}\;\lambda_2 \leq -0.00236 \lor \neg \left(\lambda_2 \leq 2.8 \cdot 10^{-19}\right):\\ \;\;\;\;\cos^{-1} \left(t\_0 \cdot \cos \phi_2\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \lambda_1, \cos \phi_2 \cdot \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right) \cdot R\\ \end{array} \end{array} \]
            (FPCore (R lambda1 lambda2 phi1 phi2)
             :precision binary64
             (let* ((t_0
                     (fma (cos lambda1) (cos lambda2) (* (sin lambda1) (sin lambda2)))))
               (if (<= lambda2 -2.2e+133)
                 (* (acos (* t_0 (cos phi1))) R)
                 (if (or (<= lambda2 -0.00236) (not (<= lambda2 2.8e-19)))
                   (* (acos (* t_0 (cos phi2))) R)
                   (*
                    (acos
                     (fma
                      (cos lambda1)
                      (* (cos phi2) (cos phi1))
                      (* (sin phi2) (sin phi1))))
                    R)))))
            double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
            	double t_0 = fma(cos(lambda1), cos(lambda2), (sin(lambda1) * sin(lambda2)));
            	double tmp;
            	if (lambda2 <= -2.2e+133) {
            		tmp = acos((t_0 * cos(phi1))) * R;
            	} else if ((lambda2 <= -0.00236) || !(lambda2 <= 2.8e-19)) {
            		tmp = acos((t_0 * cos(phi2))) * R;
            	} else {
            		tmp = acos(fma(cos(lambda1), (cos(phi2) * cos(phi1)), (sin(phi2) * sin(phi1)))) * R;
            	}
            	return tmp;
            }
            
            function code(R, lambda1, lambda2, phi1, phi2)
            	t_0 = fma(cos(lambda1), cos(lambda2), Float64(sin(lambda1) * sin(lambda2)))
            	tmp = 0.0
            	if (lambda2 <= -2.2e+133)
            		tmp = Float64(acos(Float64(t_0 * cos(phi1))) * R);
            	elseif ((lambda2 <= -0.00236) || !(lambda2 <= 2.8e-19))
            		tmp = Float64(acos(Float64(t_0 * cos(phi2))) * R);
            	else
            		tmp = Float64(acos(fma(cos(lambda1), Float64(cos(phi2) * cos(phi1)), Float64(sin(phi2) * sin(phi1)))) * R);
            	end
            	return tmp
            end
            
            code[R_, lambda1_, lambda2_, phi1_, phi2_] := Block[{t$95$0 = N[(N[Cos[lambda1], $MachinePrecision] * N[Cos[lambda2], $MachinePrecision] + N[(N[Sin[lambda1], $MachinePrecision] * N[Sin[lambda2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[lambda2, -2.2e+133], N[(N[ArcCos[N[(t$95$0 * N[Cos[phi1], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], If[Or[LessEqual[lambda2, -0.00236], N[Not[LessEqual[lambda2, 2.8e-19]], $MachinePrecision]], N[(N[ArcCos[N[(t$95$0 * N[Cos[phi2], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], N[(N[ArcCos[N[(N[Cos[lambda1], $MachinePrecision] * N[(N[Cos[phi2], $MachinePrecision] * N[Cos[phi1], $MachinePrecision]), $MachinePrecision] + N[(N[Sin[phi2], $MachinePrecision] * N[Sin[phi1], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]]]]
            
            \begin{array}{l}
            
            \\
            \begin{array}{l}
            t_0 := \mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right)\\
            \mathbf{if}\;\lambda_2 \leq -2.2 \cdot 10^{+133}:\\
            \;\;\;\;\cos^{-1} \left(t\_0 \cdot \cos \phi_1\right) \cdot R\\
            
            \mathbf{elif}\;\lambda_2 \leq -0.00236 \lor \neg \left(\lambda_2 \leq 2.8 \cdot 10^{-19}\right):\\
            \;\;\;\;\cos^{-1} \left(t\_0 \cdot \cos \phi_2\right) \cdot R\\
            
            \mathbf{else}:\\
            \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \lambda_1, \cos \phi_2 \cdot \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right) \cdot R\\
            
            
            \end{array}
            \end{array}
            
            Derivation
            1. Split input into 3 regimes
            2. if lambda2 < -2.2e133

              1. Initial program 53.2%

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

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

                  \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \color{blue}{\left(\lambda_1 - \lambda_2\right)}\right) \cdot R \]
                3. cos-diffN/A

                  \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\left(\cos \lambda_1 \cdot \cos \lambda_2 + \sin \lambda_1 \cdot \sin \lambda_2\right)}\right) \cdot R \]
                4. +-commutativeN/A

                  \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\left(\sin \lambda_1 \cdot \sin \lambda_2 + \cos \lambda_1 \cdot \cos \lambda_2\right)}\right) \cdot R \]
                5. *-commutativeN/A

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

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

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

                  \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \color{blue}{\sin \lambda_1}, \cos \lambda_1 \cdot \cos \lambda_2\right)\right) \cdot R \]
                9. *-commutativeN/A

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

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

                  \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \color{blue}{\cos \lambda_2} \cdot \cos \lambda_1\right)\right) \cdot R \]
                12. lower-cos.f6499.3

                  \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \color{blue}{\cos \lambda_1}\right)\right) \cdot R \]
              4. Applied rewrites99.3%

                \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \cos \lambda_1\right)}\right) \cdot R \]
              5. Taylor expanded in phi2 around 0

                \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \left(\cos \lambda_1 \cdot \cos \lambda_2 + \sin \lambda_1 \cdot \sin \lambda_2\right)\right)} \cdot R \]
              6. Step-by-step derivation
                1. Applied rewrites66.7%

                  \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_1\right)} \cdot R \]

                if -2.2e133 < lambda2 < -0.0023600000000000001 or 2.80000000000000003e-19 < lambda2

                1. Initial program 57.1%

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

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

                    \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \color{blue}{\left(\lambda_1 - \lambda_2\right)}\right) \cdot R \]
                  3. cos-diffN/A

                    \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\left(\cos \lambda_1 \cdot \cos \lambda_2 + \sin \lambda_1 \cdot \sin \lambda_2\right)}\right) \cdot R \]
                  4. +-commutativeN/A

                    \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\left(\sin \lambda_1 \cdot \sin \lambda_2 + \cos \lambda_1 \cdot \cos \lambda_2\right)}\right) \cdot R \]
                  5. *-commutativeN/A

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

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

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

                    \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \color{blue}{\sin \lambda_1}, \cos \lambda_1 \cdot \cos \lambda_2\right)\right) \cdot R \]
                  9. *-commutativeN/A

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

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

                    \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \color{blue}{\cos \lambda_2} \cdot \cos \lambda_1\right)\right) \cdot R \]
                  12. lower-cos.f6499.0

                    \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \color{blue}{\cos \lambda_1}\right)\right) \cdot R \]
                4. Applied rewrites99.0%

                  \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \cos \lambda_1\right)}\right) \cdot R \]
                5. Taylor expanded in phi1 around 0

                  \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_2 \cdot \left(\cos \lambda_1 \cdot \cos \lambda_2 + \sin \lambda_1 \cdot \sin \lambda_2\right)\right)} \cdot R \]
                6. Step-by-step derivation
                  1. Applied rewrites57.7%

                    \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_2\right)} \cdot R \]

                  if -0.0023600000000000001 < lambda2 < 2.80000000000000003e-19

                  1. Initial program 88.6%

                    \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                  2. Add Preprocessing
                  3. Taylor expanded in lambda2 around 0

                    \[\leadsto \cos^{-1} \color{blue}{\left(\cos \lambda_1 \cdot \left(\cos \phi_1 \cdot \cos \phi_2\right) + \sin \phi_1 \cdot \sin \phi_2\right)} \cdot R \]
                  4. Step-by-step derivation
                    1. Applied rewrites88.2%

                      \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\cos \lambda_1, \cos \phi_2 \cdot \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right)} \cdot R \]
                  5. Recombined 3 regimes into one program.
                  6. Final simplification75.7%

                    \[\leadsto \begin{array}{l} \mathbf{if}\;\lambda_2 \leq -2.2 \cdot 10^{+133}:\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_1\right) \cdot R\\ \mathbf{elif}\;\lambda_2 \leq -0.00236 \lor \neg \left(\lambda_2 \leq 2.8 \cdot 10^{-19}\right):\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_2\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \lambda_1, \cos \phi_2 \cdot \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right) \cdot R\\ \end{array} \]
                  7. Add Preprocessing

                  Alternative 7: 83.8% accurate, 1.0× speedup?

                  \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\phi_2 \leq -3 \cdot 10^{-8} \lor \neg \left(\phi_2 \leq 2.65 \cdot 10^{-11}\right):\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_1\right) \cdot R\\ \end{array} \end{array} \]
                  (FPCore (R lambda1 lambda2 phi1 phi2)
                   :precision binary64
                   (if (or (<= phi2 -3e-8) (not (<= phi2 2.65e-11)))
                     (*
                      (acos
                       (fma
                        (sin phi2)
                        (sin phi1)
                        (* (* (cos (- lambda2 lambda1)) (cos phi1)) (cos phi2))))
                      R)
                     (*
                      (acos
                       (*
                        (fma (cos lambda1) (cos lambda2) (* (sin lambda1) (sin lambda2)))
                        (cos phi1)))
                      R)))
                  double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                  	double tmp;
                  	if ((phi2 <= -3e-8) || !(phi2 <= 2.65e-11)) {
                  		tmp = acos(fma(sin(phi2), sin(phi1), ((cos((lambda2 - lambda1)) * cos(phi1)) * cos(phi2)))) * R;
                  	} else {
                  		tmp = acos((fma(cos(lambda1), cos(lambda2), (sin(lambda1) * sin(lambda2))) * cos(phi1))) * R;
                  	}
                  	return tmp;
                  }
                  
                  function code(R, lambda1, lambda2, phi1, phi2)
                  	tmp = 0.0
                  	if ((phi2 <= -3e-8) || !(phi2 <= 2.65e-11))
                  		tmp = Float64(acos(fma(sin(phi2), sin(phi1), Float64(Float64(cos(Float64(lambda2 - lambda1)) * cos(phi1)) * cos(phi2)))) * R);
                  	else
                  		tmp = Float64(acos(Float64(fma(cos(lambda1), cos(lambda2), Float64(sin(lambda1) * sin(lambda2))) * cos(phi1))) * R);
                  	end
                  	return tmp
                  end
                  
                  code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[Or[LessEqual[phi2, -3e-8], N[Not[LessEqual[phi2, 2.65e-11]], $MachinePrecision]], N[(N[ArcCos[N[(N[Sin[phi2], $MachinePrecision] * N[Sin[phi1], $MachinePrecision] + N[(N[(N[Cos[N[(lambda2 - lambda1), $MachinePrecision]], $MachinePrecision] * N[Cos[phi1], $MachinePrecision]), $MachinePrecision] * N[Cos[phi2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], N[(N[ArcCos[N[(N[(N[Cos[lambda1], $MachinePrecision] * N[Cos[lambda2], $MachinePrecision] + N[(N[Sin[lambda1], $MachinePrecision] * N[Sin[lambda2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Cos[phi1], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]]
                  
                  \begin{array}{l}
                  
                  \\
                  \begin{array}{l}
                  \mathbf{if}\;\phi_2 \leq -3 \cdot 10^{-8} \lor \neg \left(\phi_2 \leq 2.65 \cdot 10^{-11}\right):\\
                  \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R\\
                  
                  \mathbf{else}:\\
                  \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_1\right) \cdot R\\
                  
                  
                  \end{array}
                  \end{array}
                  
                  Derivation
                  1. Split input into 2 regimes
                  2. if phi2 < -2.99999999999999973e-8 or 2.6499999999999999e-11 < phi2

                    1. Initial program 81.0%

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

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

                        \[\leadsto \cos^{-1} \left(\color{blue}{\sin \phi_1 \cdot \sin \phi_2} + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                      3. *-commutativeN/A

                        \[\leadsto \cos^{-1} \left(\color{blue}{\sin \phi_2 \cdot \sin \phi_1} + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                      4. lower-fma.f6481.1

                        \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)\right)} \cdot R \]
                      5. lift-*.f64N/A

                        \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)}\right)\right) \cdot R \]
                      6. *-commutativeN/A

                        \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\cos \left(\lambda_1 - \lambda_2\right) \cdot \left(\cos \phi_1 \cdot \cos \phi_2\right)}\right)\right) \cdot R \]
                      7. lift-*.f64N/A

                        \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \cos \left(\lambda_1 - \lambda_2\right) \cdot \color{blue}{\left(\cos \phi_1 \cdot \cos \phi_2\right)}\right)\right) \cdot R \]
                      8. associate-*r*N/A

                        \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\left(\cos \left(\lambda_1 - \lambda_2\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2}\right)\right) \cdot R \]
                      9. lower-*.f64N/A

                        \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\left(\cos \left(\lambda_1 - \lambda_2\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2}\right)\right) \cdot R \]
                      10. lower-*.f6481.1

                        \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \color{blue}{\left(\cos \left(\lambda_1 - \lambda_2\right) \cdot \cos \phi_1\right)} \cdot \cos \phi_2\right)\right) \cdot R \]
                      11. lift-cos.f64N/A

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

                        \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \color{blue}{\left(\lambda_1 - \lambda_2\right)} \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
                      13. cos-diffN/A

                        \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\color{blue}{\left(\cos \lambda_1 \cdot \cos \lambda_2 + \sin \lambda_1 \cdot \sin \lambda_2\right)} \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
                      14. *-commutativeN/A

                        \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\left(\color{blue}{\cos \lambda_2 \cdot \cos \lambda_1} + \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
                      15. *-commutativeN/A

                        \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\left(\cos \lambda_2 \cdot \cos \lambda_1 + \color{blue}{\sin \lambda_2 \cdot \sin \lambda_1}\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
                      16. cos-diff-revN/A

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

                        \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\color{blue}{\cos \left(\lambda_2 - \lambda_1\right)} \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
                      18. lower--.f6481.1

                        \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \color{blue}{\left(\lambda_2 - \lambda_1\right)} \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
                    4. Applied rewrites81.1%

                      \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right)} \cdot R \]

                    if -2.99999999999999973e-8 < phi2 < 2.6499999999999999e-11

                    1. Initial program 66.3%

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

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

                        \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \color{blue}{\left(\lambda_1 - \lambda_2\right)}\right) \cdot R \]
                      3. cos-diffN/A

                        \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\left(\cos \lambda_1 \cdot \cos \lambda_2 + \sin \lambda_1 \cdot \sin \lambda_2\right)}\right) \cdot R \]
                      4. +-commutativeN/A

                        \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\left(\sin \lambda_1 \cdot \sin \lambda_2 + \cos \lambda_1 \cdot \cos \lambda_2\right)}\right) \cdot R \]
                      5. *-commutativeN/A

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

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

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

                        \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \color{blue}{\sin \lambda_1}, \cos \lambda_1 \cdot \cos \lambda_2\right)\right) \cdot R \]
                      9. *-commutativeN/A

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

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

                        \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \color{blue}{\cos \lambda_2} \cdot \cos \lambda_1\right)\right) \cdot R \]
                      12. lower-cos.f6488.8

                        \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \color{blue}{\cos \lambda_1}\right)\right) \cdot R \]
                    4. Applied rewrites88.8%

                      \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \cos \lambda_1\right)}\right) \cdot R \]
                    5. Taylor expanded in phi2 around 0

                      \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \left(\cos \lambda_1 \cdot \cos \lambda_2 + \sin \lambda_1 \cdot \sin \lambda_2\right)\right)} \cdot R \]
                    6. Step-by-step derivation
                      1. Applied rewrites88.5%

                        \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_1\right)} \cdot R \]
                    7. Recombined 2 regimes into one program.
                    8. Final simplification84.8%

                      \[\leadsto \begin{array}{l} \mathbf{if}\;\phi_2 \leq -3 \cdot 10^{-8} \lor \neg \left(\phi_2 \leq 2.65 \cdot 10^{-11}\right):\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_1\right) \cdot R\\ \end{array} \]
                    9. Add Preprocessing

                    Alternative 8: 73.9% accurate, 1.0× speedup?

                    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\lambda_1 \leq -1.65 \cdot 10^{-6} \lor \neg \left(\lambda_1 \leq 1.65 \cdot 10^{-10}\right):\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \lambda_1, \cos \phi_2 \cdot \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \lambda_2 \cdot \cos \phi_2\right) \cdot \cos \phi_1\right)\right) \cdot R\\ \end{array} \end{array} \]
                    (FPCore (R lambda1 lambda2 phi1 phi2)
                     :precision binary64
                     (if (or (<= lambda1 -1.65e-6) (not (<= lambda1 1.65e-10)))
                       (*
                        (acos
                         (fma (cos lambda1) (* (cos phi2) (cos phi1)) (* (sin phi2) (sin phi1))))
                        R)
                       (*
                        (acos
                         (fma (sin phi2) (sin phi1) (* (* (cos lambda2) (cos phi2)) (cos phi1))))
                        R)))
                    double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                    	double tmp;
                    	if ((lambda1 <= -1.65e-6) || !(lambda1 <= 1.65e-10)) {
                    		tmp = acos(fma(cos(lambda1), (cos(phi2) * cos(phi1)), (sin(phi2) * sin(phi1)))) * R;
                    	} else {
                    		tmp = acos(fma(sin(phi2), sin(phi1), ((cos(lambda2) * cos(phi2)) * cos(phi1)))) * R;
                    	}
                    	return tmp;
                    }
                    
                    function code(R, lambda1, lambda2, phi1, phi2)
                    	tmp = 0.0
                    	if ((lambda1 <= -1.65e-6) || !(lambda1 <= 1.65e-10))
                    		tmp = Float64(acos(fma(cos(lambda1), Float64(cos(phi2) * cos(phi1)), Float64(sin(phi2) * sin(phi1)))) * R);
                    	else
                    		tmp = Float64(acos(fma(sin(phi2), sin(phi1), Float64(Float64(cos(lambda2) * cos(phi2)) * cos(phi1)))) * R);
                    	end
                    	return tmp
                    end
                    
                    code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[Or[LessEqual[lambda1, -1.65e-6], N[Not[LessEqual[lambda1, 1.65e-10]], $MachinePrecision]], N[(N[ArcCos[N[(N[Cos[lambda1], $MachinePrecision] * N[(N[Cos[phi2], $MachinePrecision] * N[Cos[phi1], $MachinePrecision]), $MachinePrecision] + N[(N[Sin[phi2], $MachinePrecision] * N[Sin[phi1], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], N[(N[ArcCos[N[(N[Sin[phi2], $MachinePrecision] * N[Sin[phi1], $MachinePrecision] + N[(N[(N[Cos[lambda2], $MachinePrecision] * N[Cos[phi2], $MachinePrecision]), $MachinePrecision] * N[Cos[phi1], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]]
                    
                    \begin{array}{l}
                    
                    \\
                    \begin{array}{l}
                    \mathbf{if}\;\lambda_1 \leq -1.65 \cdot 10^{-6} \lor \neg \left(\lambda_1 \leq 1.65 \cdot 10^{-10}\right):\\
                    \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \lambda_1, \cos \phi_2 \cdot \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right) \cdot R\\
                    
                    \mathbf{else}:\\
                    \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \lambda_2 \cdot \cos \phi_2\right) \cdot \cos \phi_1\right)\right) \cdot R\\
                    
                    
                    \end{array}
                    \end{array}
                    
                    Derivation
                    1. Split input into 2 regimes
                    2. if lambda1 < -1.65000000000000008e-6 or 1.65e-10 < lambda1

                      1. Initial program 63.0%

                        \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                      2. Add Preprocessing
                      3. Taylor expanded in lambda2 around 0

                        \[\leadsto \cos^{-1} \color{blue}{\left(\cos \lambda_1 \cdot \left(\cos \phi_1 \cdot \cos \phi_2\right) + \sin \phi_1 \cdot \sin \phi_2\right)} \cdot R \]
                      4. Step-by-step derivation
                        1. Applied rewrites62.9%

                          \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\cos \lambda_1, \cos \phi_2 \cdot \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right)} \cdot R \]

                        if -1.65000000000000008e-6 < lambda1 < 1.65e-10

                        1. Initial program 86.8%

                          \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                        2. Add Preprocessing
                        3. Taylor expanded in lambda1 around 0

                          \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \left(\cos \phi_2 \cdot \cos \left(\mathsf{neg}\left(\lambda_2\right)\right)\right) + \sin \phi_1 \cdot \sin \phi_2\right)} \cdot R \]
                        4. Step-by-step derivation
                          1. Applied rewrites86.8%

                            \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\cos \lambda_2 \cdot \cos \phi_2, \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right)} \cdot R \]
                          2. Step-by-step derivation
                            1. Applied rewrites86.9%

                              \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \color{blue}{\sin \phi_1}, \left(\cos \lambda_2 \cdot \cos \phi_2\right) \cdot \cos \phi_1\right)\right) \cdot R \]
                          3. Recombined 2 regimes into one program.
                          4. Final simplification73.6%

                            \[\leadsto \begin{array}{l} \mathbf{if}\;\lambda_1 \leq -1.65 \cdot 10^{-6} \lor \neg \left(\lambda_1 \leq 1.65 \cdot 10^{-10}\right):\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \lambda_1, \cos \phi_2 \cdot \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \lambda_2 \cdot \cos \phi_2\right) \cdot \cos \phi_1\right)\right) \cdot R\\ \end{array} \]
                          5. Add Preprocessing

                          Alternative 9: 73.2% accurate, 1.0× speedup?

                          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\lambda_2 \leq -2.15 \cdot 10^{-12}:\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_1\right) \cdot R\\ \mathbf{elif}\;\lambda_2 \leq 3.5 \cdot 10^{-6}:\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \lambda_1, \cos \phi_2 \cdot \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \lambda_2 \cdot \cos \phi_2\right) \cdot \cos \phi_1\right)\right) \cdot R\\ \end{array} \end{array} \]
                          (FPCore (R lambda1 lambda2 phi1 phi2)
                           :precision binary64
                           (if (<= lambda2 -2.15e-12)
                             (*
                              (acos
                               (*
                                (fma (cos lambda1) (cos lambda2) (* (sin lambda1) (sin lambda2)))
                                (cos phi1)))
                              R)
                             (if (<= lambda2 3.5e-6)
                               (*
                                (acos
                                 (fma (cos lambda1) (* (cos phi2) (cos phi1)) (* (sin phi2) (sin phi1))))
                                R)
                               (*
                                (acos
                                 (fma (sin phi2) (sin phi1) (* (* (cos lambda2) (cos phi2)) (cos phi1))))
                                R))))
                          double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                          	double tmp;
                          	if (lambda2 <= -2.15e-12) {
                          		tmp = acos((fma(cos(lambda1), cos(lambda2), (sin(lambda1) * sin(lambda2))) * cos(phi1))) * R;
                          	} else if (lambda2 <= 3.5e-6) {
                          		tmp = acos(fma(cos(lambda1), (cos(phi2) * cos(phi1)), (sin(phi2) * sin(phi1)))) * R;
                          	} else {
                          		tmp = acos(fma(sin(phi2), sin(phi1), ((cos(lambda2) * cos(phi2)) * cos(phi1)))) * R;
                          	}
                          	return tmp;
                          }
                          
                          function code(R, lambda1, lambda2, phi1, phi2)
                          	tmp = 0.0
                          	if (lambda2 <= -2.15e-12)
                          		tmp = Float64(acos(Float64(fma(cos(lambda1), cos(lambda2), Float64(sin(lambda1) * sin(lambda2))) * cos(phi1))) * R);
                          	elseif (lambda2 <= 3.5e-6)
                          		tmp = Float64(acos(fma(cos(lambda1), Float64(cos(phi2) * cos(phi1)), Float64(sin(phi2) * sin(phi1)))) * R);
                          	else
                          		tmp = Float64(acos(fma(sin(phi2), sin(phi1), Float64(Float64(cos(lambda2) * cos(phi2)) * cos(phi1)))) * R);
                          	end
                          	return tmp
                          end
                          
                          code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[LessEqual[lambda2, -2.15e-12], N[(N[ArcCos[N[(N[(N[Cos[lambda1], $MachinePrecision] * N[Cos[lambda2], $MachinePrecision] + N[(N[Sin[lambda1], $MachinePrecision] * N[Sin[lambda2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Cos[phi1], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], If[LessEqual[lambda2, 3.5e-6], N[(N[ArcCos[N[(N[Cos[lambda1], $MachinePrecision] * N[(N[Cos[phi2], $MachinePrecision] * N[Cos[phi1], $MachinePrecision]), $MachinePrecision] + N[(N[Sin[phi2], $MachinePrecision] * N[Sin[phi1], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], N[(N[ArcCos[N[(N[Sin[phi2], $MachinePrecision] * N[Sin[phi1], $MachinePrecision] + N[(N[(N[Cos[lambda2], $MachinePrecision] * N[Cos[phi2], $MachinePrecision]), $MachinePrecision] * N[Cos[phi1], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]]]
                          
                          \begin{array}{l}
                          
                          \\
                          \begin{array}{l}
                          \mathbf{if}\;\lambda_2 \leq -2.15 \cdot 10^{-12}:\\
                          \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_1\right) \cdot R\\
                          
                          \mathbf{elif}\;\lambda_2 \leq 3.5 \cdot 10^{-6}:\\
                          \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \lambda_1, \cos \phi_2 \cdot \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right) \cdot R\\
                          
                          \mathbf{else}:\\
                          \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \sin \phi_1, \left(\cos \lambda_2 \cdot \cos \phi_2\right) \cdot \cos \phi_1\right)\right) \cdot R\\
                          
                          
                          \end{array}
                          \end{array}
                          
                          Derivation
                          1. Split input into 3 regimes
                          2. if lambda2 < -2.14999999999999993e-12

                            1. Initial program 54.6%

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

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

                                \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \color{blue}{\left(\lambda_1 - \lambda_2\right)}\right) \cdot R \]
                              3. cos-diffN/A

                                \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\left(\cos \lambda_1 \cdot \cos \lambda_2 + \sin \lambda_1 \cdot \sin \lambda_2\right)}\right) \cdot R \]
                              4. +-commutativeN/A

                                \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\left(\sin \lambda_1 \cdot \sin \lambda_2 + \cos \lambda_1 \cdot \cos \lambda_2\right)}\right) \cdot R \]
                              5. *-commutativeN/A

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

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

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

                                \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \color{blue}{\sin \lambda_1}, \cos \lambda_1 \cdot \cos \lambda_2\right)\right) \cdot R \]
                              9. *-commutativeN/A

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

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

                                \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \color{blue}{\cos \lambda_2} \cdot \cos \lambda_1\right)\right) \cdot R \]
                              12. lower-cos.f6499.1

                                \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \color{blue}{\cos \lambda_1}\right)\right) \cdot R \]
                            4. Applied rewrites99.1%

                              \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \color{blue}{\mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \cos \lambda_1\right)}\right) \cdot R \]
                            5. Taylor expanded in phi2 around 0

                              \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \left(\cos \lambda_1 \cdot \cos \lambda_2 + \sin \lambda_1 \cdot \sin \lambda_2\right)\right)} \cdot R \]
                            6. Step-by-step derivation
                              1. Applied rewrites63.9%

                                \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\cos \lambda_1, \cos \lambda_2, \sin \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_1\right)} \cdot R \]

                              if -2.14999999999999993e-12 < lambda2 < 3.49999999999999995e-6

                              1. Initial program 89.0%

                                \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                              2. Add Preprocessing
                              3. Taylor expanded in lambda2 around 0

                                \[\leadsto \cos^{-1} \color{blue}{\left(\cos \lambda_1 \cdot \left(\cos \phi_1 \cdot \cos \phi_2\right) + \sin \phi_1 \cdot \sin \phi_2\right)} \cdot R \]
                              4. Step-by-step derivation
                                1. Applied rewrites88.9%

                                  \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\cos \lambda_1, \cos \phi_2 \cdot \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right)} \cdot R \]

                                if 3.49999999999999995e-6 < lambda2

                                1. Initial program 58.2%

                                  \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                2. Add Preprocessing
                                3. Taylor expanded in lambda1 around 0

                                  \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \left(\cos \phi_2 \cdot \cos \left(\mathsf{neg}\left(\lambda_2\right)\right)\right) + \sin \phi_1 \cdot \sin \phi_2\right)} \cdot R \]
                                4. Step-by-step derivation
                                  1. Applied rewrites58.4%

                                    \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\cos \lambda_2 \cdot \cos \phi_2, \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right)} \cdot R \]
                                  2. Step-by-step derivation
                                    1. Applied rewrites58.4%

                                      \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \phi_2, \color{blue}{\sin \phi_1}, \left(\cos \lambda_2 \cdot \cos \phi_2\right) \cdot \cos \phi_1\right)\right) \cdot R \]
                                  3. Recombined 3 regimes into one program.
                                  4. Add Preprocessing

                                  Alternative 10: 63.2% accurate, 1.0× speedup?

                                  \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\lambda_2 \leq -0.0034:\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \cos \lambda_1\right)\right) \cdot R\\ \mathbf{elif}\;\lambda_2 \leq 0.0037:\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \lambda_1, \cos \phi_2 \cdot \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\cos \lambda_2 \cdot \cos \phi_2\right) \cdot R\\ \end{array} \end{array} \]
                                  (FPCore (R lambda1 lambda2 phi1 phi2)
                                   :precision binary64
                                   (if (<= lambda2 -0.0034)
                                     (*
                                      (acos (fma (sin lambda2) (sin lambda1) (* (cos lambda2) (cos lambda1))))
                                      R)
                                     (if (<= lambda2 0.0037)
                                       (*
                                        (acos
                                         (fma (cos lambda1) (* (cos phi2) (cos phi1)) (* (sin phi2) (sin phi1))))
                                        R)
                                       (* (acos (* (cos lambda2) (cos phi2))) R))))
                                  double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                                  	double tmp;
                                  	if (lambda2 <= -0.0034) {
                                  		tmp = acos(fma(sin(lambda2), sin(lambda1), (cos(lambda2) * cos(lambda1)))) * R;
                                  	} else if (lambda2 <= 0.0037) {
                                  		tmp = acos(fma(cos(lambda1), (cos(phi2) * cos(phi1)), (sin(phi2) * sin(phi1)))) * R;
                                  	} else {
                                  		tmp = acos((cos(lambda2) * cos(phi2))) * R;
                                  	}
                                  	return tmp;
                                  }
                                  
                                  function code(R, lambda1, lambda2, phi1, phi2)
                                  	tmp = 0.0
                                  	if (lambda2 <= -0.0034)
                                  		tmp = Float64(acos(fma(sin(lambda2), sin(lambda1), Float64(cos(lambda2) * cos(lambda1)))) * R);
                                  	elseif (lambda2 <= 0.0037)
                                  		tmp = Float64(acos(fma(cos(lambda1), Float64(cos(phi2) * cos(phi1)), Float64(sin(phi2) * sin(phi1)))) * R);
                                  	else
                                  		tmp = Float64(acos(Float64(cos(lambda2) * cos(phi2))) * R);
                                  	end
                                  	return tmp
                                  end
                                  
                                  code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[LessEqual[lambda2, -0.0034], N[(N[ArcCos[N[(N[Sin[lambda2], $MachinePrecision] * N[Sin[lambda1], $MachinePrecision] + N[(N[Cos[lambda2], $MachinePrecision] * N[Cos[lambda1], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], If[LessEqual[lambda2, 0.0037], N[(N[ArcCos[N[(N[Cos[lambda1], $MachinePrecision] * N[(N[Cos[phi2], $MachinePrecision] * N[Cos[phi1], $MachinePrecision]), $MachinePrecision] + N[(N[Sin[phi2], $MachinePrecision] * N[Sin[phi1], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], N[(N[ArcCos[N[(N[Cos[lambda2], $MachinePrecision] * N[Cos[phi2], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]]]
                                  
                                  \begin{array}{l}
                                  
                                  \\
                                  \begin{array}{l}
                                  \mathbf{if}\;\lambda_2 \leq -0.0034:\\
                                  \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \cos \lambda_1\right)\right) \cdot R\\
                                  
                                  \mathbf{elif}\;\lambda_2 \leq 0.0037:\\
                                  \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \lambda_1, \cos \phi_2 \cdot \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right) \cdot R\\
                                  
                                  \mathbf{else}:\\
                                  \;\;\;\;\cos^{-1} \left(\cos \lambda_2 \cdot \cos \phi_2\right) \cdot R\\
                                  
                                  
                                  \end{array}
                                  \end{array}
                                  
                                  Derivation
                                  1. Split input into 3 regimes
                                  2. if lambda2 < -0.00339999999999999981

                                    1. Initial program 53.3%

                                      \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                    2. Add Preprocessing
                                    3. Taylor expanded in phi2 around 0

                                      \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)} \cdot R \]
                                    4. Step-by-step derivation
                                      1. Applied rewrites36.2%

                                        \[\leadsto \cos^{-1} \color{blue}{\left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right)} \cdot R \]
                                      2. Taylor expanded in phi1 around 0

                                        \[\leadsto \cos^{-1} \cos \left(\lambda_2 - \lambda_1\right) \cdot R \]
                                      3. Step-by-step derivation
                                        1. Applied rewrites32.0%

                                          \[\leadsto \cos^{-1} \cos \left(\lambda_1 - \lambda_2\right) \cdot R \]
                                        2. Step-by-step derivation
                                          1. Applied rewrites42.8%

                                            \[\leadsto \cos^{-1} \left(\mathsf{fma}\left(\sin \lambda_2, \sin \lambda_1, \cos \lambda_2 \cdot \cos \lambda_1\right)\right) \cdot R \]

                                          if -0.00339999999999999981 < lambda2 < 0.0037000000000000002

                                          1. Initial program 88.3%

                                            \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                          2. Add Preprocessing
                                          3. Taylor expanded in lambda2 around 0

                                            \[\leadsto \cos^{-1} \color{blue}{\left(\cos \lambda_1 \cdot \left(\cos \phi_1 \cdot \cos \phi_2\right) + \sin \phi_1 \cdot \sin \phi_2\right)} \cdot R \]
                                          4. Step-by-step derivation
                                            1. Applied rewrites87.9%

                                              \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\cos \lambda_1, \cos \phi_2 \cdot \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right)} \cdot R \]

                                            if 0.0037000000000000002 < lambda2

                                            1. Initial program 58.2%

                                              \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                            2. Add Preprocessing
                                            3. Taylor expanded in lambda1 around 0

                                              \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \left(\cos \phi_2 \cdot \cos \left(\mathsf{neg}\left(\lambda_2\right)\right)\right) + \sin \phi_1 \cdot \sin \phi_2\right)} \cdot R \]
                                            4. Step-by-step derivation
                                              1. Applied rewrites58.4%

                                                \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\cos \lambda_2 \cdot \cos \phi_2, \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right)} \cdot R \]
                                              2. Taylor expanded in phi1 around 0

                                                \[\leadsto \cos^{-1} \left(\cos \lambda_2 \cdot \color{blue}{\cos \phi_2}\right) \cdot R \]
                                              3. Step-by-step derivation
                                                1. Applied rewrites38.0%

                                                  \[\leadsto \cos^{-1} \left(\cos \lambda_2 \cdot \color{blue}{\cos \phi_2}\right) \cdot R \]
                                              4. Recombined 3 regimes into one program.
                                              5. Add Preprocessing

                                              Alternative 11: 55.3% accurate, 1.2× speedup?

                                              \[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos \left(\lambda_2 - \lambda_1\right)\\ \mathbf{if}\;\phi_1 \leq -0.016:\\ \;\;\;\;\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + t\_0 \cdot \cos \phi_1\right) \cdot R\\ \mathbf{elif}\;\phi_1 \leq 1.1 \cdot 10^{-19}:\\ \;\;\;\;\cos^{-1} \left(\left(\mathsf{fma}\left(-0.16666666666666666, \phi_1 \cdot \phi_1, 1\right) \cdot \sin \phi_2\right) \cdot \phi_1 + \mathsf{fma}\left(\phi_1, -0.5 \cdot \phi_1, 1\right) \cdot \left(t\_0 \cdot \cos \phi_2\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \phi_2, \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right) \cdot R\\ \end{array} \end{array} \]
                                              (FPCore (R lambda1 lambda2 phi1 phi2)
                                               :precision binary64
                                               (let* ((t_0 (cos (- lambda2 lambda1))))
                                                 (if (<= phi1 -0.016)
                                                   (* (acos (+ (* (sin phi1) (sin phi2)) (* t_0 (cos phi1)))) R)
                                                   (if (<= phi1 1.1e-19)
                                                     (*
                                                      (acos
                                                       (+
                                                        (* (* (fma -0.16666666666666666 (* phi1 phi1) 1.0) (sin phi2)) phi1)
                                                        (* (fma phi1 (* -0.5 phi1) 1.0) (* t_0 (cos phi2)))))
                                                      R)
                                                     (* (acos (fma (cos phi2) (cos phi1) (* (sin phi2) (sin phi1)))) R)))))
                                              double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                                              	double t_0 = cos((lambda2 - lambda1));
                                              	double tmp;
                                              	if (phi1 <= -0.016) {
                                              		tmp = acos(((sin(phi1) * sin(phi2)) + (t_0 * cos(phi1)))) * R;
                                              	} else if (phi1 <= 1.1e-19) {
                                              		tmp = acos((((fma(-0.16666666666666666, (phi1 * phi1), 1.0) * sin(phi2)) * phi1) + (fma(phi1, (-0.5 * phi1), 1.0) * (t_0 * cos(phi2))))) * R;
                                              	} else {
                                              		tmp = acos(fma(cos(phi2), cos(phi1), (sin(phi2) * sin(phi1)))) * R;
                                              	}
                                              	return tmp;
                                              }
                                              
                                              function code(R, lambda1, lambda2, phi1, phi2)
                                              	t_0 = cos(Float64(lambda2 - lambda1))
                                              	tmp = 0.0
                                              	if (phi1 <= -0.016)
                                              		tmp = Float64(acos(Float64(Float64(sin(phi1) * sin(phi2)) + Float64(t_0 * cos(phi1)))) * R);
                                              	elseif (phi1 <= 1.1e-19)
                                              		tmp = Float64(acos(Float64(Float64(Float64(fma(-0.16666666666666666, Float64(phi1 * phi1), 1.0) * sin(phi2)) * phi1) + Float64(fma(phi1, Float64(-0.5 * phi1), 1.0) * Float64(t_0 * cos(phi2))))) * R);
                                              	else
                                              		tmp = Float64(acos(fma(cos(phi2), cos(phi1), Float64(sin(phi2) * sin(phi1)))) * R);
                                              	end
                                              	return tmp
                                              end
                                              
                                              code[R_, lambda1_, lambda2_, phi1_, phi2_] := Block[{t$95$0 = N[Cos[N[(lambda2 - lambda1), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[phi1, -0.016], N[(N[ArcCos[N[(N[(N[Sin[phi1], $MachinePrecision] * N[Sin[phi2], $MachinePrecision]), $MachinePrecision] + N[(t$95$0 * N[Cos[phi1], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], If[LessEqual[phi1, 1.1e-19], N[(N[ArcCos[N[(N[(N[(N[(-0.16666666666666666 * N[(phi1 * phi1), $MachinePrecision] + 1.0), $MachinePrecision] * N[Sin[phi2], $MachinePrecision]), $MachinePrecision] * phi1), $MachinePrecision] + N[(N[(phi1 * N[(-0.5 * phi1), $MachinePrecision] + 1.0), $MachinePrecision] * N[(t$95$0 * N[Cos[phi2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], N[(N[ArcCos[N[(N[Cos[phi2], $MachinePrecision] * N[Cos[phi1], $MachinePrecision] + N[(N[Sin[phi2], $MachinePrecision] * N[Sin[phi1], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]]]]
                                              
                                              \begin{array}{l}
                                              
                                              \\
                                              \begin{array}{l}
                                              t_0 := \cos \left(\lambda_2 - \lambda_1\right)\\
                                              \mathbf{if}\;\phi_1 \leq -0.016:\\
                                              \;\;\;\;\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + t\_0 \cdot \cos \phi_1\right) \cdot R\\
                                              
                                              \mathbf{elif}\;\phi_1 \leq 1.1 \cdot 10^{-19}:\\
                                              \;\;\;\;\cos^{-1} \left(\left(\mathsf{fma}\left(-0.16666666666666666, \phi_1 \cdot \phi_1, 1\right) \cdot \sin \phi_2\right) \cdot \phi_1 + \mathsf{fma}\left(\phi_1, -0.5 \cdot \phi_1, 1\right) \cdot \left(t\_0 \cdot \cos \phi_2\right)\right) \cdot R\\
                                              
                                              \mathbf{else}:\\
                                              \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \phi_2, \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right) \cdot R\\
                                              
                                              
                                              \end{array}
                                              \end{array}
                                              
                                              Derivation
                                              1. Split input into 3 regimes
                                              2. if phi1 < -0.016

                                                1. Initial program 78.7%

                                                  \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                2. Add Preprocessing
                                                3. Taylor expanded in phi2 around 0

                                                  \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \color{blue}{\cos \phi_1 \cdot \cos \left(\lambda_1 - \lambda_2\right)}\right) \cdot R \]
                                                4. Step-by-step derivation
                                                  1. Applied rewrites45.7%

                                                    \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \color{blue}{\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1}\right) \cdot R \]

                                                  if -0.016 < phi1 < 1.0999999999999999e-19

                                                  1. Initial program 69.0%

                                                    \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                  2. Add Preprocessing
                                                  3. Taylor expanded in phi1 around 0

                                                    \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \color{blue}{\left(\frac{-1}{2} \cdot \left({\phi_1}^{2} \cdot \left(\cos \phi_2 \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)\right) + \cos \phi_2 \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)}\right) \cdot R \]
                                                  4. Applied rewrites69.0%

                                                    \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \color{blue}{\mathsf{fma}\left(\phi_1, -0.5 \cdot \phi_1, 1\right) \cdot \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_2\right)}\right) \cdot R \]
                                                  5. Taylor expanded in phi1 around 0

                                                    \[\leadsto \cos^{-1} \left(\color{blue}{\phi_1 \cdot \left(\sin \phi_2 + \frac{-1}{6} \cdot \left({\phi_1}^{2} \cdot \sin \phi_2\right)\right)} + \mathsf{fma}\left(\phi_1, \frac{-1}{2} \cdot \phi_1, 1\right) \cdot \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
                                                  6. Step-by-step derivation
                                                    1. Applied rewrites69.0%

                                                      \[\leadsto \cos^{-1} \left(\color{blue}{\left(\mathsf{fma}\left(-0.16666666666666666, \phi_1 \cdot \phi_1, 1\right) \cdot \sin \phi_2\right) \cdot \phi_1} + \mathsf{fma}\left(\phi_1, -0.5 \cdot \phi_1, 1\right) \cdot \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]

                                                    if 1.0999999999999999e-19 < phi1

                                                    1. Initial program 76.3%

                                                      \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                    2. Add Preprocessing
                                                    3. Taylor expanded in lambda1 around 0

                                                      \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \left(\cos \phi_2 \cdot \cos \left(\mathsf{neg}\left(\lambda_2\right)\right)\right) + \sin \phi_1 \cdot \sin \phi_2\right)} \cdot R \]
                                                    4. Step-by-step derivation
                                                      1. Applied rewrites57.4%

                                                        \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\cos \lambda_2 \cdot \cos \phi_2, \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right)} \cdot R \]
                                                      2. Taylor expanded in lambda2 around 0

                                                        \[\leadsto \cos^{-1} \left(\cos \phi_1 \cdot \cos \phi_2 + \color{blue}{\sin \phi_1 \cdot \sin \phi_2}\right) \cdot R \]
                                                      3. Step-by-step derivation
                                                        1. Applied rewrites43.9%

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

                                                      Alternative 12: 55.5% accurate, 1.2× speedup?

                                                      \[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos \left(\lambda_2 - \lambda_1\right)\\ \mathbf{if}\;\phi_1 \leq -0.016:\\ \;\;\;\;\cos^{-1} \left(t\_0 \cdot \cos \phi_1\right) \cdot R\\ \mathbf{elif}\;\phi_1 \leq 1.1 \cdot 10^{-19}:\\ \;\;\;\;\cos^{-1} \left(\left(\mathsf{fma}\left(-0.16666666666666666, \phi_1 \cdot \phi_1, 1\right) \cdot \sin \phi_2\right) \cdot \phi_1 + \mathsf{fma}\left(\phi_1, -0.5 \cdot \phi_1, 1\right) \cdot \left(t\_0 \cdot \cos \phi_2\right)\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \phi_2, \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right) \cdot R\\ \end{array} \end{array} \]
                                                      (FPCore (R lambda1 lambda2 phi1 phi2)
                                                       :precision binary64
                                                       (let* ((t_0 (cos (- lambda2 lambda1))))
                                                         (if (<= phi1 -0.016)
                                                           (* (acos (* t_0 (cos phi1))) R)
                                                           (if (<= phi1 1.1e-19)
                                                             (*
                                                              (acos
                                                               (+
                                                                (* (* (fma -0.16666666666666666 (* phi1 phi1) 1.0) (sin phi2)) phi1)
                                                                (* (fma phi1 (* -0.5 phi1) 1.0) (* t_0 (cos phi2)))))
                                                              R)
                                                             (* (acos (fma (cos phi2) (cos phi1) (* (sin phi2) (sin phi1)))) R)))))
                                                      double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                                                      	double t_0 = cos((lambda2 - lambda1));
                                                      	double tmp;
                                                      	if (phi1 <= -0.016) {
                                                      		tmp = acos((t_0 * cos(phi1))) * R;
                                                      	} else if (phi1 <= 1.1e-19) {
                                                      		tmp = acos((((fma(-0.16666666666666666, (phi1 * phi1), 1.0) * sin(phi2)) * phi1) + (fma(phi1, (-0.5 * phi1), 1.0) * (t_0 * cos(phi2))))) * R;
                                                      	} else {
                                                      		tmp = acos(fma(cos(phi2), cos(phi1), (sin(phi2) * sin(phi1)))) * R;
                                                      	}
                                                      	return tmp;
                                                      }
                                                      
                                                      function code(R, lambda1, lambda2, phi1, phi2)
                                                      	t_0 = cos(Float64(lambda2 - lambda1))
                                                      	tmp = 0.0
                                                      	if (phi1 <= -0.016)
                                                      		tmp = Float64(acos(Float64(t_0 * cos(phi1))) * R);
                                                      	elseif (phi1 <= 1.1e-19)
                                                      		tmp = Float64(acos(Float64(Float64(Float64(fma(-0.16666666666666666, Float64(phi1 * phi1), 1.0) * sin(phi2)) * phi1) + Float64(fma(phi1, Float64(-0.5 * phi1), 1.0) * Float64(t_0 * cos(phi2))))) * R);
                                                      	else
                                                      		tmp = Float64(acos(fma(cos(phi2), cos(phi1), Float64(sin(phi2) * sin(phi1)))) * R);
                                                      	end
                                                      	return tmp
                                                      end
                                                      
                                                      code[R_, lambda1_, lambda2_, phi1_, phi2_] := Block[{t$95$0 = N[Cos[N[(lambda2 - lambda1), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[phi1, -0.016], N[(N[ArcCos[N[(t$95$0 * N[Cos[phi1], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], If[LessEqual[phi1, 1.1e-19], N[(N[ArcCos[N[(N[(N[(N[(-0.16666666666666666 * N[(phi1 * phi1), $MachinePrecision] + 1.0), $MachinePrecision] * N[Sin[phi2], $MachinePrecision]), $MachinePrecision] * phi1), $MachinePrecision] + N[(N[(phi1 * N[(-0.5 * phi1), $MachinePrecision] + 1.0), $MachinePrecision] * N[(t$95$0 * N[Cos[phi2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], N[(N[ArcCos[N[(N[Cos[phi2], $MachinePrecision] * N[Cos[phi1], $MachinePrecision] + N[(N[Sin[phi2], $MachinePrecision] * N[Sin[phi1], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]]]]
                                                      
                                                      \begin{array}{l}
                                                      
                                                      \\
                                                      \begin{array}{l}
                                                      t_0 := \cos \left(\lambda_2 - \lambda_1\right)\\
                                                      \mathbf{if}\;\phi_1 \leq -0.016:\\
                                                      \;\;\;\;\cos^{-1} \left(t\_0 \cdot \cos \phi_1\right) \cdot R\\
                                                      
                                                      \mathbf{elif}\;\phi_1 \leq 1.1 \cdot 10^{-19}:\\
                                                      \;\;\;\;\cos^{-1} \left(\left(\mathsf{fma}\left(-0.16666666666666666, \phi_1 \cdot \phi_1, 1\right) \cdot \sin \phi_2\right) \cdot \phi_1 + \mathsf{fma}\left(\phi_1, -0.5 \cdot \phi_1, 1\right) \cdot \left(t\_0 \cdot \cos \phi_2\right)\right) \cdot R\\
                                                      
                                                      \mathbf{else}:\\
                                                      \;\;\;\;\cos^{-1} \left(\mathsf{fma}\left(\cos \phi_2, \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right) \cdot R\\
                                                      
                                                      
                                                      \end{array}
                                                      \end{array}
                                                      
                                                      Derivation
                                                      1. Split input into 3 regimes
                                                      2. if phi1 < -0.016

                                                        1. Initial program 78.7%

                                                          \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                        2. Add Preprocessing
                                                        3. Taylor expanded in phi2 around 0

                                                          \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)} \cdot R \]
                                                        4. Step-by-step derivation
                                                          1. Applied rewrites45.9%

                                                            \[\leadsto \cos^{-1} \color{blue}{\left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right)} \cdot R \]

                                                          if -0.016 < phi1 < 1.0999999999999999e-19

                                                          1. Initial program 69.0%

                                                            \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                          2. Add Preprocessing
                                                          3. Taylor expanded in phi1 around 0

                                                            \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \color{blue}{\left(\frac{-1}{2} \cdot \left({\phi_1}^{2} \cdot \left(\cos \phi_2 \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)\right) + \cos \phi_2 \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)}\right) \cdot R \]
                                                          4. Applied rewrites69.0%

                                                            \[\leadsto \cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \color{blue}{\mathsf{fma}\left(\phi_1, -0.5 \cdot \phi_1, 1\right) \cdot \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_2\right)}\right) \cdot R \]
                                                          5. Taylor expanded in phi1 around 0

                                                            \[\leadsto \cos^{-1} \left(\color{blue}{\phi_1 \cdot \left(\sin \phi_2 + \frac{-1}{6} \cdot \left({\phi_1}^{2} \cdot \sin \phi_2\right)\right)} + \mathsf{fma}\left(\phi_1, \frac{-1}{2} \cdot \phi_1, 1\right) \cdot \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]
                                                          6. Step-by-step derivation
                                                            1. Applied rewrites69.0%

                                                              \[\leadsto \cos^{-1} \left(\color{blue}{\left(\mathsf{fma}\left(-0.16666666666666666, \phi_1 \cdot \phi_1, 1\right) \cdot \sin \phi_2\right) \cdot \phi_1} + \mathsf{fma}\left(\phi_1, -0.5 \cdot \phi_1, 1\right) \cdot \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_2\right)\right) \cdot R \]

                                                            if 1.0999999999999999e-19 < phi1

                                                            1. Initial program 76.3%

                                                              \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                            2. Add Preprocessing
                                                            3. Taylor expanded in lambda1 around 0

                                                              \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \left(\cos \phi_2 \cdot \cos \left(\mathsf{neg}\left(\lambda_2\right)\right)\right) + \sin \phi_1 \cdot \sin \phi_2\right)} \cdot R \]
                                                            4. Step-by-step derivation
                                                              1. Applied rewrites57.4%

                                                                \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\cos \lambda_2 \cdot \cos \phi_2, \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right)} \cdot R \]
                                                              2. Taylor expanded in lambda2 around 0

                                                                \[\leadsto \cos^{-1} \left(\cos \phi_1 \cdot \cos \phi_2 + \color{blue}{\sin \phi_1 \cdot \sin \phi_2}\right) \cdot R \]
                                                              3. Step-by-step derivation
                                                                1. Applied rewrites43.9%

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

                                                              Alternative 13: 50.6% accurate, 2.0× speedup?

                                                              \[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos \left(\lambda_2 - \lambda_1\right)\\ \mathbf{if}\;\phi_2 \leq 0.00066:\\ \;\;\;\;\cos^{-1} \left(t\_0 \cdot \cos \phi_1\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(t\_0 \cdot \cos \phi_2\right) \cdot R\\ \end{array} \end{array} \]
                                                              (FPCore (R lambda1 lambda2 phi1 phi2)
                                                               :precision binary64
                                                               (let* ((t_0 (cos (- lambda2 lambda1))))
                                                                 (if (<= phi2 0.00066)
                                                                   (* (acos (* t_0 (cos phi1))) R)
                                                                   (* (acos (* t_0 (cos phi2))) R))))
                                                              double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                                                              	double t_0 = cos((lambda2 - lambda1));
                                                              	double tmp;
                                                              	if (phi2 <= 0.00066) {
                                                              		tmp = acos((t_0 * cos(phi1))) * R;
                                                              	} else {
                                                              		tmp = acos((t_0 * cos(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) :: t_0
                                                                  real(8) :: tmp
                                                                  t_0 = cos((lambda2 - lambda1))
                                                                  if (phi2 <= 0.00066d0) then
                                                                      tmp = acos((t_0 * cos(phi1))) * r
                                                                  else
                                                                      tmp = acos((t_0 * cos(phi2))) * r
                                                                  end if
                                                                  code = tmp
                                                              end function
                                                              
                                                              public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                                                              	double t_0 = Math.cos((lambda2 - lambda1));
                                                              	double tmp;
                                                              	if (phi2 <= 0.00066) {
                                                              		tmp = Math.acos((t_0 * Math.cos(phi1))) * R;
                                                              	} else {
                                                              		tmp = Math.acos((t_0 * Math.cos(phi2))) * R;
                                                              	}
                                                              	return tmp;
                                                              }
                                                              
                                                              def code(R, lambda1, lambda2, phi1, phi2):
                                                              	t_0 = math.cos((lambda2 - lambda1))
                                                              	tmp = 0
                                                              	if phi2 <= 0.00066:
                                                              		tmp = math.acos((t_0 * math.cos(phi1))) * R
                                                              	else:
                                                              		tmp = math.acos((t_0 * math.cos(phi2))) * R
                                                              	return tmp
                                                              
                                                              function code(R, lambda1, lambda2, phi1, phi2)
                                                              	t_0 = cos(Float64(lambda2 - lambda1))
                                                              	tmp = 0.0
                                                              	if (phi2 <= 0.00066)
                                                              		tmp = Float64(acos(Float64(t_0 * cos(phi1))) * R);
                                                              	else
                                                              		tmp = Float64(acos(Float64(t_0 * cos(phi2))) * R);
                                                              	end
                                                              	return tmp
                                                              end
                                                              
                                                              function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
                                                              	t_0 = cos((lambda2 - lambda1));
                                                              	tmp = 0.0;
                                                              	if (phi2 <= 0.00066)
                                                              		tmp = acos((t_0 * cos(phi1))) * R;
                                                              	else
                                                              		tmp = acos((t_0 * cos(phi2))) * R;
                                                              	end
                                                              	tmp_2 = tmp;
                                                              end
                                                              
                                                              code[R_, lambda1_, lambda2_, phi1_, phi2_] := Block[{t$95$0 = N[Cos[N[(lambda2 - lambda1), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[phi2, 0.00066], N[(N[ArcCos[N[(t$95$0 * N[Cos[phi1], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], N[(N[ArcCos[N[(t$95$0 * N[Cos[phi2], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]]]
                                                              
                                                              \begin{array}{l}
                                                              
                                                              \\
                                                              \begin{array}{l}
                                                              t_0 := \cos \left(\lambda_2 - \lambda_1\right)\\
                                                              \mathbf{if}\;\phi_2 \leq 0.00066:\\
                                                              \;\;\;\;\cos^{-1} \left(t\_0 \cdot \cos \phi_1\right) \cdot R\\
                                                              
                                                              \mathbf{else}:\\
                                                              \;\;\;\;\cos^{-1} \left(t\_0 \cdot \cos \phi_2\right) \cdot R\\
                                                              
                                                              
                                                              \end{array}
                                                              \end{array}
                                                              
                                                              Derivation
                                                              1. Split input into 2 regimes
                                                              2. if phi2 < 6.6e-4

                                                                1. Initial program 70.6%

                                                                  \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                                2. Add Preprocessing
                                                                3. Taylor expanded in phi2 around 0

                                                                  \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)} \cdot R \]
                                                                4. Step-by-step derivation
                                                                  1. Applied rewrites50.9%

                                                                    \[\leadsto \cos^{-1} \color{blue}{\left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right)} \cdot R \]

                                                                  if 6.6e-4 < phi2

                                                                  1. Initial program 82.6%

                                                                    \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                                  2. Add Preprocessing
                                                                  3. Taylor expanded in phi1 around 0

                                                                    \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_2 \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)} \cdot R \]
                                                                  4. Step-by-step derivation
                                                                    1. Applied rewrites41.9%

                                                                      \[\leadsto \cos^{-1} \color{blue}{\left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_2\right)} \cdot R \]
                                                                  5. Recombined 2 regimes into one program.
                                                                  6. Add Preprocessing

                                                                  Alternative 14: 48.2% accurate, 2.0× speedup?

                                                                  \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\phi_2 \leq 0.0012:\\ \;\;\;\;\cos^{-1} \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\cos \lambda_2 \cdot \cos \phi_2\right) \cdot R\\ \end{array} \end{array} \]
                                                                  (FPCore (R lambda1 lambda2 phi1 phi2)
                                                                   :precision binary64
                                                                   (if (<= phi2 0.0012)
                                                                     (* (acos (* (cos (- lambda2 lambda1)) (cos phi1))) R)
                                                                     (* (acos (* (cos lambda2) (cos phi2))) R)))
                                                                  double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                                                                  	double tmp;
                                                                  	if (phi2 <= 0.0012) {
                                                                  		tmp = acos((cos((lambda2 - lambda1)) * cos(phi1))) * R;
                                                                  	} else {
                                                                  		tmp = acos((cos(lambda2) * cos(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 (phi2 <= 0.0012d0) then
                                                                          tmp = acos((cos((lambda2 - lambda1)) * cos(phi1))) * r
                                                                      else
                                                                          tmp = acos((cos(lambda2) * cos(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 (phi2 <= 0.0012) {
                                                                  		tmp = Math.acos((Math.cos((lambda2 - lambda1)) * Math.cos(phi1))) * R;
                                                                  	} else {
                                                                  		tmp = Math.acos((Math.cos(lambda2) * Math.cos(phi2))) * R;
                                                                  	}
                                                                  	return tmp;
                                                                  }
                                                                  
                                                                  def code(R, lambda1, lambda2, phi1, phi2):
                                                                  	tmp = 0
                                                                  	if phi2 <= 0.0012:
                                                                  		tmp = math.acos((math.cos((lambda2 - lambda1)) * math.cos(phi1))) * R
                                                                  	else:
                                                                  		tmp = math.acos((math.cos(lambda2) * math.cos(phi2))) * R
                                                                  	return tmp
                                                                  
                                                                  function code(R, lambda1, lambda2, phi1, phi2)
                                                                  	tmp = 0.0
                                                                  	if (phi2 <= 0.0012)
                                                                  		tmp = Float64(acos(Float64(cos(Float64(lambda2 - lambda1)) * cos(phi1))) * R);
                                                                  	else
                                                                  		tmp = Float64(acos(Float64(cos(lambda2) * cos(phi2))) * R);
                                                                  	end
                                                                  	return tmp
                                                                  end
                                                                  
                                                                  function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
                                                                  	tmp = 0.0;
                                                                  	if (phi2 <= 0.0012)
                                                                  		tmp = acos((cos((lambda2 - lambda1)) * cos(phi1))) * R;
                                                                  	else
                                                                  		tmp = acos((cos(lambda2) * cos(phi2))) * R;
                                                                  	end
                                                                  	tmp_2 = tmp;
                                                                  end
                                                                  
                                                                  code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[LessEqual[phi2, 0.0012], N[(N[ArcCos[N[(N[Cos[N[(lambda2 - lambda1), $MachinePrecision]], $MachinePrecision] * N[Cos[phi1], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], N[(N[ArcCos[N[(N[Cos[lambda2], $MachinePrecision] * N[Cos[phi2], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]]
                                                                  
                                                                  \begin{array}{l}
                                                                  
                                                                  \\
                                                                  \begin{array}{l}
                                                                  \mathbf{if}\;\phi_2 \leq 0.0012:\\
                                                                  \;\;\;\;\cos^{-1} \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right) \cdot R\\
                                                                  
                                                                  \mathbf{else}:\\
                                                                  \;\;\;\;\cos^{-1} \left(\cos \lambda_2 \cdot \cos \phi_2\right) \cdot R\\
                                                                  
                                                                  
                                                                  \end{array}
                                                                  \end{array}
                                                                  
                                                                  Derivation
                                                                  1. Split input into 2 regimes
                                                                  2. if phi2 < 0.00119999999999999989

                                                                    1. Initial program 70.6%

                                                                      \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                                    2. Add Preprocessing
                                                                    3. Taylor expanded in phi2 around 0

                                                                      \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)} \cdot R \]
                                                                    4. Step-by-step derivation
                                                                      1. Applied rewrites50.9%

                                                                        \[\leadsto \cos^{-1} \color{blue}{\left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right)} \cdot R \]

                                                                      if 0.00119999999999999989 < phi2

                                                                      1. Initial program 82.6%

                                                                        \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                                      2. Add Preprocessing
                                                                      3. Taylor expanded in lambda1 around 0

                                                                        \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \left(\cos \phi_2 \cdot \cos \left(\mathsf{neg}\left(\lambda_2\right)\right)\right) + \sin \phi_1 \cdot \sin \phi_2\right)} \cdot R \]
                                                                      4. Step-by-step derivation
                                                                        1. Applied rewrites64.5%

                                                                          \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\cos \lambda_2 \cdot \cos \phi_2, \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right)} \cdot R \]
                                                                        2. Taylor expanded in phi1 around 0

                                                                          \[\leadsto \cos^{-1} \left(\cos \lambda_2 \cdot \color{blue}{\cos \phi_2}\right) \cdot R \]
                                                                        3. Step-by-step derivation
                                                                          1. Applied rewrites35.2%

                                                                            \[\leadsto \cos^{-1} \left(\cos \lambda_2 \cdot \color{blue}{\cos \phi_2}\right) \cdot R \]
                                                                        4. Recombined 2 regimes into one program.
                                                                        5. Add Preprocessing

                                                                        Alternative 15: 27.3% accurate, 2.0× speedup?

                                                                        \[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos \left(\lambda_1 - \lambda_2\right)\\ \mathbf{if}\;t\_0 \leq 0.9999972332340062:\\ \;\;\;\;\cos^{-1} t\_0 \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\sin \phi_2 \cdot \phi_1\right) \cdot R\\ \end{array} \end{array} \]
                                                                        (FPCore (R lambda1 lambda2 phi1 phi2)
                                                                         :precision binary64
                                                                         (let* ((t_0 (cos (- lambda1 lambda2))))
                                                                           (if (<= t_0 0.9999972332340062)
                                                                             (* (acos t_0) R)
                                                                             (* (acos (* (sin phi2) phi1)) R))))
                                                                        double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                                                                        	double t_0 = cos((lambda1 - lambda2));
                                                                        	double tmp;
                                                                        	if (t_0 <= 0.9999972332340062) {
                                                                        		tmp = acos(t_0) * R;
                                                                        	} else {
                                                                        		tmp = acos((sin(phi2) * phi1)) * 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) :: t_0
                                                                            real(8) :: tmp
                                                                            t_0 = cos((lambda1 - lambda2))
                                                                            if (t_0 <= 0.9999972332340062d0) then
                                                                                tmp = acos(t_0) * r
                                                                            else
                                                                                tmp = acos((sin(phi2) * phi1)) * r
                                                                            end if
                                                                            code = tmp
                                                                        end function
                                                                        
                                                                        public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                                                                        	double t_0 = Math.cos((lambda1 - lambda2));
                                                                        	double tmp;
                                                                        	if (t_0 <= 0.9999972332340062) {
                                                                        		tmp = Math.acos(t_0) * R;
                                                                        	} else {
                                                                        		tmp = Math.acos((Math.sin(phi2) * phi1)) * R;
                                                                        	}
                                                                        	return tmp;
                                                                        }
                                                                        
                                                                        def code(R, lambda1, lambda2, phi1, phi2):
                                                                        	t_0 = math.cos((lambda1 - lambda2))
                                                                        	tmp = 0
                                                                        	if t_0 <= 0.9999972332340062:
                                                                        		tmp = math.acos(t_0) * R
                                                                        	else:
                                                                        		tmp = math.acos((math.sin(phi2) * phi1)) * R
                                                                        	return tmp
                                                                        
                                                                        function code(R, lambda1, lambda2, phi1, phi2)
                                                                        	t_0 = cos(Float64(lambda1 - lambda2))
                                                                        	tmp = 0.0
                                                                        	if (t_0 <= 0.9999972332340062)
                                                                        		tmp = Float64(acos(t_0) * R);
                                                                        	else
                                                                        		tmp = Float64(acos(Float64(sin(phi2) * phi1)) * R);
                                                                        	end
                                                                        	return tmp
                                                                        end
                                                                        
                                                                        function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
                                                                        	t_0 = cos((lambda1 - lambda2));
                                                                        	tmp = 0.0;
                                                                        	if (t_0 <= 0.9999972332340062)
                                                                        		tmp = acos(t_0) * R;
                                                                        	else
                                                                        		tmp = acos((sin(phi2) * phi1)) * R;
                                                                        	end
                                                                        	tmp_2 = tmp;
                                                                        end
                                                                        
                                                                        code[R_, lambda1_, lambda2_, phi1_, phi2_] := Block[{t$95$0 = N[Cos[N[(lambda1 - lambda2), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[t$95$0, 0.9999972332340062], N[(N[ArcCos[t$95$0], $MachinePrecision] * R), $MachinePrecision], N[(N[ArcCos[N[(N[Sin[phi2], $MachinePrecision] * phi1), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]]]
                                                                        
                                                                        \begin{array}{l}
                                                                        
                                                                        \\
                                                                        \begin{array}{l}
                                                                        t_0 := \cos \left(\lambda_1 - \lambda_2\right)\\
                                                                        \mathbf{if}\;t\_0 \leq 0.9999972332340062:\\
                                                                        \;\;\;\;\cos^{-1} t\_0 \cdot R\\
                                                                        
                                                                        \mathbf{else}:\\
                                                                        \;\;\;\;\cos^{-1} \left(\sin \phi_2 \cdot \phi_1\right) \cdot R\\
                                                                        
                                                                        
                                                                        \end{array}
                                                                        \end{array}
                                                                        
                                                                        Derivation
                                                                        1. Split input into 2 regimes
                                                                        2. if (cos.f64 (-.f64 lambda1 lambda2)) < 0.999997233234006244

                                                                          1. Initial program 72.4%

                                                                            \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                                          2. Add Preprocessing
                                                                          3. Taylor expanded in phi2 around 0

                                                                            \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)} \cdot R \]
                                                                          4. Step-by-step derivation
                                                                            1. Applied rewrites44.4%

                                                                              \[\leadsto \cos^{-1} \color{blue}{\left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right)} \cdot R \]
                                                                            2. Taylor expanded in phi1 around 0

                                                                              \[\leadsto \cos^{-1} \cos \left(\lambda_2 - \lambda_1\right) \cdot R \]
                                                                            3. Step-by-step derivation
                                                                              1. Applied rewrites34.7%

                                                                                \[\leadsto \cos^{-1} \cos \left(\lambda_1 - \lambda_2\right) \cdot R \]

                                                                              if 0.999997233234006244 < (cos.f64 (-.f64 lambda1 lambda2))

                                                                              1. Initial program 77.1%

                                                                                \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                                              2. Add Preprocessing
                                                                              3. Applied rewrites77.0%

                                                                                \[\leadsto \cos^{-1} \color{blue}{\left(\frac{{\left(\sin \phi_2 \cdot \sin \phi_1\right)}^{2} - \left(\left(-\cos \left(\lambda_2 - \lambda_1\right)\right) \cdot \left(\cos \phi_2 \cdot \cos \phi_1\right)\right) \cdot \left(\left(-\cos \left(\lambda_2 - \lambda_1\right)\right) \cdot \left(\cos \phi_2 \cdot \cos \phi_1\right)\right)}{\sin \phi_2 \cdot \sin \phi_1 - \left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right) \cdot \cos \phi_2}\right)} \cdot R \]
                                                                              4. Taylor expanded in phi1 around 0

                                                                                \[\leadsto \cos^{-1} \color{blue}{\left(\phi_1 \cdot \sin \phi_2 + \cos \phi_2 \cdot \cos \left(\lambda_2 - \lambda_1\right)\right)} \cdot R \]
                                                                              5. Step-by-step derivation
                                                                                1. Applied rewrites21.8%

                                                                                  \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\cos \left(\lambda_1 - \lambda_2\right), \cos \phi_2, \sin \phi_2 \cdot \phi_1\right)\right)} \cdot R \]
                                                                                2. Taylor expanded in phi1 around inf

                                                                                  \[\leadsto \cos^{-1} \left(\phi_1 \cdot \color{blue}{\sin \phi_2}\right) \cdot R \]
                                                                                3. Step-by-step derivation
                                                                                  1. Applied rewrites8.8%

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

                                                                                Alternative 16: 37.2% accurate, 2.0× speedup?

                                                                                \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\phi_2 \leq 3.3 \cdot 10^{-11}:\\ \;\;\;\;\cos^{-1} \left(\cos \lambda_1 \cdot \cos \phi_1\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\cos \lambda_2 \cdot \cos \phi_2\right) \cdot R\\ \end{array} \end{array} \]
                                                                                (FPCore (R lambda1 lambda2 phi1 phi2)
                                                                                 :precision binary64
                                                                                 (if (<= phi2 3.3e-11)
                                                                                   (* (acos (* (cos lambda1) (cos phi1))) R)
                                                                                   (* (acos (* (cos lambda2) (cos phi2))) R)))
                                                                                double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                                                                                	double tmp;
                                                                                	if (phi2 <= 3.3e-11) {
                                                                                		tmp = acos((cos(lambda1) * cos(phi1))) * R;
                                                                                	} else {
                                                                                		tmp = acos((cos(lambda2) * cos(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 (phi2 <= 3.3d-11) then
                                                                                        tmp = acos((cos(lambda1) * cos(phi1))) * r
                                                                                    else
                                                                                        tmp = acos((cos(lambda2) * cos(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 (phi2 <= 3.3e-11) {
                                                                                		tmp = Math.acos((Math.cos(lambda1) * Math.cos(phi1))) * R;
                                                                                	} else {
                                                                                		tmp = Math.acos((Math.cos(lambda2) * Math.cos(phi2))) * R;
                                                                                	}
                                                                                	return tmp;
                                                                                }
                                                                                
                                                                                def code(R, lambda1, lambda2, phi1, phi2):
                                                                                	tmp = 0
                                                                                	if phi2 <= 3.3e-11:
                                                                                		tmp = math.acos((math.cos(lambda1) * math.cos(phi1))) * R
                                                                                	else:
                                                                                		tmp = math.acos((math.cos(lambda2) * math.cos(phi2))) * R
                                                                                	return tmp
                                                                                
                                                                                function code(R, lambda1, lambda2, phi1, phi2)
                                                                                	tmp = 0.0
                                                                                	if (phi2 <= 3.3e-11)
                                                                                		tmp = Float64(acos(Float64(cos(lambda1) * cos(phi1))) * R);
                                                                                	else
                                                                                		tmp = Float64(acos(Float64(cos(lambda2) * cos(phi2))) * R);
                                                                                	end
                                                                                	return tmp
                                                                                end
                                                                                
                                                                                function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
                                                                                	tmp = 0.0;
                                                                                	if (phi2 <= 3.3e-11)
                                                                                		tmp = acos((cos(lambda1) * cos(phi1))) * R;
                                                                                	else
                                                                                		tmp = acos((cos(lambda2) * cos(phi2))) * R;
                                                                                	end
                                                                                	tmp_2 = tmp;
                                                                                end
                                                                                
                                                                                code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[LessEqual[phi2, 3.3e-11], N[(N[ArcCos[N[(N[Cos[lambda1], $MachinePrecision] * N[Cos[phi1], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], N[(N[ArcCos[N[(N[Cos[lambda2], $MachinePrecision] * N[Cos[phi2], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]]
                                                                                
                                                                                \begin{array}{l}
                                                                                
                                                                                \\
                                                                                \begin{array}{l}
                                                                                \mathbf{if}\;\phi_2 \leq 3.3 \cdot 10^{-11}:\\
                                                                                \;\;\;\;\cos^{-1} \left(\cos \lambda_1 \cdot \cos \phi_1\right) \cdot R\\
                                                                                
                                                                                \mathbf{else}:\\
                                                                                \;\;\;\;\cos^{-1} \left(\cos \lambda_2 \cdot \cos \phi_2\right) \cdot R\\
                                                                                
                                                                                
                                                                                \end{array}
                                                                                \end{array}
                                                                                
                                                                                Derivation
                                                                                1. Split input into 2 regimes
                                                                                2. if phi2 < 3.3000000000000002e-11

                                                                                  1. Initial program 70.3%

                                                                                    \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                                                  2. Add Preprocessing
                                                                                  3. Taylor expanded in phi2 around 0

                                                                                    \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)} \cdot R \]
                                                                                  4. Step-by-step derivation
                                                                                    1. Applied rewrites50.7%

                                                                                      \[\leadsto \cos^{-1} \color{blue}{\left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right)} \cdot R \]
                                                                                    2. Taylor expanded in lambda2 around 0

                                                                                      \[\leadsto \cos^{-1} \left(\cos \left(\mathsf{neg}\left(\lambda_1\right)\right) \cdot \cos \color{blue}{\phi_1}\right) \cdot R \]
                                                                                    3. Step-by-step derivation
                                                                                      1. Applied rewrites39.0%

                                                                                        \[\leadsto \cos^{-1} \left(\cos \lambda_1 \cdot \cos \color{blue}{\phi_1}\right) \cdot R \]

                                                                                      if 3.3000000000000002e-11 < phi2

                                                                                      1. Initial program 83.1%

                                                                                        \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                                                      2. Add Preprocessing
                                                                                      3. Taylor expanded in lambda1 around 0

                                                                                        \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \left(\cos \phi_2 \cdot \cos \left(\mathsf{neg}\left(\lambda_2\right)\right)\right) + \sin \phi_1 \cdot \sin \phi_2\right)} \cdot R \]
                                                                                      4. Step-by-step derivation
                                                                                        1. Applied rewrites64.3%

                                                                                          \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\cos \lambda_2 \cdot \cos \phi_2, \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right)} \cdot R \]
                                                                                        2. Taylor expanded in phi1 around 0

                                                                                          \[\leadsto \cos^{-1} \left(\cos \lambda_2 \cdot \color{blue}{\cos \phi_2}\right) \cdot R \]
                                                                                        3. Step-by-step derivation
                                                                                          1. Applied rewrites35.9%

                                                                                            \[\leadsto \cos^{-1} \left(\cos \lambda_2 \cdot \color{blue}{\cos \phi_2}\right) \cdot R \]
                                                                                        4. Recombined 2 regimes into one program.
                                                                                        5. Final simplification38.2%

                                                                                          \[\leadsto \begin{array}{l} \mathbf{if}\;\phi_2 \leq 3.3 \cdot 10^{-11}:\\ \;\;\;\;\cos^{-1} \left(\cos \lambda_1 \cdot \cos \phi_1\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\cos \lambda_2 \cdot \cos \phi_2\right) \cdot R\\ \end{array} \]
                                                                                        6. Add Preprocessing

                                                                                        Alternative 17: 32.2% accurate, 2.0× speedup?

                                                                                        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\phi_2 \leq 0.00066:\\ \;\;\;\;\cos^{-1} \cos \left(\lambda_1 - \lambda_2\right) \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \left(\cos \lambda_2 \cdot \cos \phi_2\right) \cdot R\\ \end{array} \end{array} \]
                                                                                        (FPCore (R lambda1 lambda2 phi1 phi2)
                                                                                         :precision binary64
                                                                                         (if (<= phi2 0.00066)
                                                                                           (* (acos (cos (- lambda1 lambda2))) R)
                                                                                           (* (acos (* (cos lambda2) (cos phi2))) R)))
                                                                                        double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                                                                                        	double tmp;
                                                                                        	if (phi2 <= 0.00066) {
                                                                                        		tmp = acos(cos((lambda1 - lambda2))) * R;
                                                                                        	} else {
                                                                                        		tmp = acos((cos(lambda2) * cos(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 (phi2 <= 0.00066d0) then
                                                                                                tmp = acos(cos((lambda1 - lambda2))) * r
                                                                                            else
                                                                                                tmp = acos((cos(lambda2) * cos(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 (phi2 <= 0.00066) {
                                                                                        		tmp = Math.acos(Math.cos((lambda1 - lambda2))) * R;
                                                                                        	} else {
                                                                                        		tmp = Math.acos((Math.cos(lambda2) * Math.cos(phi2))) * R;
                                                                                        	}
                                                                                        	return tmp;
                                                                                        }
                                                                                        
                                                                                        def code(R, lambda1, lambda2, phi1, phi2):
                                                                                        	tmp = 0
                                                                                        	if phi2 <= 0.00066:
                                                                                        		tmp = math.acos(math.cos((lambda1 - lambda2))) * R
                                                                                        	else:
                                                                                        		tmp = math.acos((math.cos(lambda2) * math.cos(phi2))) * R
                                                                                        	return tmp
                                                                                        
                                                                                        function code(R, lambda1, lambda2, phi1, phi2)
                                                                                        	tmp = 0.0
                                                                                        	if (phi2 <= 0.00066)
                                                                                        		tmp = Float64(acos(cos(Float64(lambda1 - lambda2))) * R);
                                                                                        	else
                                                                                        		tmp = Float64(acos(Float64(cos(lambda2) * cos(phi2))) * R);
                                                                                        	end
                                                                                        	return tmp
                                                                                        end
                                                                                        
                                                                                        function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
                                                                                        	tmp = 0.0;
                                                                                        	if (phi2 <= 0.00066)
                                                                                        		tmp = acos(cos((lambda1 - lambda2))) * R;
                                                                                        	else
                                                                                        		tmp = acos((cos(lambda2) * cos(phi2))) * R;
                                                                                        	end
                                                                                        	tmp_2 = tmp;
                                                                                        end
                                                                                        
                                                                                        code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[LessEqual[phi2, 0.00066], N[(N[ArcCos[N[Cos[N[(lambda1 - lambda2), $MachinePrecision]], $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], N[(N[ArcCos[N[(N[Cos[lambda2], $MachinePrecision] * N[Cos[phi2], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]]
                                                                                        
                                                                                        \begin{array}{l}
                                                                                        
                                                                                        \\
                                                                                        \begin{array}{l}
                                                                                        \mathbf{if}\;\phi_2 \leq 0.00066:\\
                                                                                        \;\;\;\;\cos^{-1} \cos \left(\lambda_1 - \lambda_2\right) \cdot R\\
                                                                                        
                                                                                        \mathbf{else}:\\
                                                                                        \;\;\;\;\cos^{-1} \left(\cos \lambda_2 \cdot \cos \phi_2\right) \cdot R\\
                                                                                        
                                                                                        
                                                                                        \end{array}
                                                                                        \end{array}
                                                                                        
                                                                                        Derivation
                                                                                        1. Split input into 2 regimes
                                                                                        2. if phi2 < 6.6e-4

                                                                                          1. Initial program 70.6%

                                                                                            \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                                                          2. Add Preprocessing
                                                                                          3. Taylor expanded in phi2 around 0

                                                                                            \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)} \cdot R \]
                                                                                          4. Step-by-step derivation
                                                                                            1. Applied rewrites50.9%

                                                                                              \[\leadsto \cos^{-1} \color{blue}{\left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right)} \cdot R \]
                                                                                            2. Taylor expanded in phi1 around 0

                                                                                              \[\leadsto \cos^{-1} \cos \left(\lambda_2 - \lambda_1\right) \cdot R \]
                                                                                            3. Step-by-step derivation
                                                                                              1. Applied rewrites30.7%

                                                                                                \[\leadsto \cos^{-1} \cos \left(\lambda_1 - \lambda_2\right) \cdot R \]

                                                                                              if 6.6e-4 < phi2

                                                                                              1. Initial program 82.6%

                                                                                                \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                                                              2. Add Preprocessing
                                                                                              3. Taylor expanded in lambda1 around 0

                                                                                                \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \left(\cos \phi_2 \cdot \cos \left(\mathsf{neg}\left(\lambda_2\right)\right)\right) + \sin \phi_1 \cdot \sin \phi_2\right)} \cdot R \]
                                                                                              4. Step-by-step derivation
                                                                                                1. Applied rewrites64.5%

                                                                                                  \[\leadsto \cos^{-1} \color{blue}{\left(\mathsf{fma}\left(\cos \lambda_2 \cdot \cos \phi_2, \cos \phi_1, \sin \phi_2 \cdot \sin \phi_1\right)\right)} \cdot R \]
                                                                                                2. Taylor expanded in phi1 around 0

                                                                                                  \[\leadsto \cos^{-1} \left(\cos \lambda_2 \cdot \color{blue}{\cos \phi_2}\right) \cdot R \]
                                                                                                3. Step-by-step derivation
                                                                                                  1. Applied rewrites35.2%

                                                                                                    \[\leadsto \cos^{-1} \left(\cos \lambda_2 \cdot \color{blue}{\cos \phi_2}\right) \cdot R \]
                                                                                                4. Recombined 2 regimes into one program.
                                                                                                5. Add Preprocessing

                                                                                                Alternative 18: 26.6% accurate, 2.9× speedup?

                                                                                                \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\lambda_1 \leq -1.42 \cdot 10^{-6} \lor \neg \left(\lambda_1 \leq 1.65 \cdot 10^{-10}\right):\\ \;\;\;\;\cos^{-1} \cos \lambda_1 \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \cos \lambda_2 \cdot R\\ \end{array} \end{array} \]
                                                                                                (FPCore (R lambda1 lambda2 phi1 phi2)
                                                                                                 :precision binary64
                                                                                                 (if (or (<= lambda1 -1.42e-6) (not (<= lambda1 1.65e-10)))
                                                                                                   (* (acos (cos lambda1)) R)
                                                                                                   (* (acos (cos lambda2)) R)))
                                                                                                double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                                                                                                	double tmp;
                                                                                                	if ((lambda1 <= -1.42e-6) || !(lambda1 <= 1.65e-10)) {
                                                                                                		tmp = acos(cos(lambda1)) * R;
                                                                                                	} else {
                                                                                                		tmp = acos(cos(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 ((lambda1 <= (-1.42d-6)) .or. (.not. (lambda1 <= 1.65d-10))) then
                                                                                                        tmp = acos(cos(lambda1)) * r
                                                                                                    else
                                                                                                        tmp = acos(cos(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 ((lambda1 <= -1.42e-6) || !(lambda1 <= 1.65e-10)) {
                                                                                                		tmp = Math.acos(Math.cos(lambda1)) * R;
                                                                                                	} else {
                                                                                                		tmp = Math.acos(Math.cos(lambda2)) * R;
                                                                                                	}
                                                                                                	return tmp;
                                                                                                }
                                                                                                
                                                                                                def code(R, lambda1, lambda2, phi1, phi2):
                                                                                                	tmp = 0
                                                                                                	if (lambda1 <= -1.42e-6) or not (lambda1 <= 1.65e-10):
                                                                                                		tmp = math.acos(math.cos(lambda1)) * R
                                                                                                	else:
                                                                                                		tmp = math.acos(math.cos(lambda2)) * R
                                                                                                	return tmp
                                                                                                
                                                                                                function code(R, lambda1, lambda2, phi1, phi2)
                                                                                                	tmp = 0.0
                                                                                                	if ((lambda1 <= -1.42e-6) || !(lambda1 <= 1.65e-10))
                                                                                                		tmp = Float64(acos(cos(lambda1)) * R);
                                                                                                	else
                                                                                                		tmp = Float64(acos(cos(lambda2)) * R);
                                                                                                	end
                                                                                                	return tmp
                                                                                                end
                                                                                                
                                                                                                function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
                                                                                                	tmp = 0.0;
                                                                                                	if ((lambda1 <= -1.42e-6) || ~((lambda1 <= 1.65e-10)))
                                                                                                		tmp = acos(cos(lambda1)) * R;
                                                                                                	else
                                                                                                		tmp = acos(cos(lambda2)) * R;
                                                                                                	end
                                                                                                	tmp_2 = tmp;
                                                                                                end
                                                                                                
                                                                                                code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[Or[LessEqual[lambda1, -1.42e-6], N[Not[LessEqual[lambda1, 1.65e-10]], $MachinePrecision]], N[(N[ArcCos[N[Cos[lambda1], $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision], N[(N[ArcCos[N[Cos[lambda2], $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]]
                                                                                                
                                                                                                \begin{array}{l}
                                                                                                
                                                                                                \\
                                                                                                \begin{array}{l}
                                                                                                \mathbf{if}\;\lambda_1 \leq -1.42 \cdot 10^{-6} \lor \neg \left(\lambda_1 \leq 1.65 \cdot 10^{-10}\right):\\
                                                                                                \;\;\;\;\cos^{-1} \cos \lambda_1 \cdot R\\
                                                                                                
                                                                                                \mathbf{else}:\\
                                                                                                \;\;\;\;\cos^{-1} \cos \lambda_2 \cdot R\\
                                                                                                
                                                                                                
                                                                                                \end{array}
                                                                                                \end{array}
                                                                                                
                                                                                                Derivation
                                                                                                1. Split input into 2 regimes
                                                                                                2. if lambda1 < -1.42e-6 or 1.65e-10 < lambda1

                                                                                                  1. Initial program 63.0%

                                                                                                    \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                                                                  2. Add Preprocessing
                                                                                                  3. Taylor expanded in phi2 around 0

                                                                                                    \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)} \cdot R \]
                                                                                                  4. Step-by-step derivation
                                                                                                    1. Applied rewrites38.9%

                                                                                                      \[\leadsto \cos^{-1} \color{blue}{\left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right)} \cdot R \]
                                                                                                    2. Taylor expanded in phi1 around 0

                                                                                                      \[\leadsto \cos^{-1} \cos \left(\lambda_2 - \lambda_1\right) \cdot R \]
                                                                                                    3. Step-by-step derivation
                                                                                                      1. Applied rewrites30.8%

                                                                                                        \[\leadsto \cos^{-1} \cos \left(\lambda_1 - \lambda_2\right) \cdot R \]
                                                                                                      2. Taylor expanded in lambda2 around 0

                                                                                                        \[\leadsto \cos^{-1} \cos \lambda_1 \cdot R \]
                                                                                                      3. Step-by-step derivation
                                                                                                        1. Applied rewrites30.9%

                                                                                                          \[\leadsto \cos^{-1} \cos \lambda_1 \cdot R \]

                                                                                                        if -1.42e-6 < lambda1 < 1.65e-10

                                                                                                        1. Initial program 86.8%

                                                                                                          \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                                                                        2. Add Preprocessing
                                                                                                        3. Taylor expanded in phi2 around 0

                                                                                                          \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)} \cdot R \]
                                                                                                        4. Step-by-step derivation
                                                                                                          1. Applied rewrites48.1%

                                                                                                            \[\leadsto \cos^{-1} \color{blue}{\left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right)} \cdot R \]
                                                                                                          2. Taylor expanded in phi1 around 0

                                                                                                            \[\leadsto \cos^{-1} \cos \left(\lambda_2 - \lambda_1\right) \cdot R \]
                                                                                                          3. Step-by-step derivation
                                                                                                            1. Applied rewrites22.1%

                                                                                                              \[\leadsto \cos^{-1} \cos \left(\lambda_1 - \lambda_2\right) \cdot R \]
                                                                                                            2. Taylor expanded in lambda1 around 0

                                                                                                              \[\leadsto \cos^{-1} \cos \left(\mathsf{neg}\left(\lambda_2\right)\right) \cdot R \]
                                                                                                            3. Step-by-step derivation
                                                                                                              1. Applied rewrites22.1%

                                                                                                                \[\leadsto \cos^{-1} \cos \lambda_2 \cdot R \]
                                                                                                            4. Recombined 2 regimes into one program.
                                                                                                            5. Final simplification27.0%

                                                                                                              \[\leadsto \begin{array}{l} \mathbf{if}\;\lambda_1 \leq -1.42 \cdot 10^{-6} \lor \neg \left(\lambda_1 \leq 1.65 \cdot 10^{-10}\right):\\ \;\;\;\;\cos^{-1} \cos \lambda_1 \cdot R\\ \mathbf{else}:\\ \;\;\;\;\cos^{-1} \cos \lambda_2 \cdot R\\ \end{array} \]
                                                                                                            6. Add Preprocessing

                                                                                                            Alternative 19: 26.7% accurate, 3.0× speedup?

                                                                                                            \[\begin{array}{l} \\ \cos^{-1} \cos \left(\lambda_1 - \lambda_2\right) \cdot R \end{array} \]
                                                                                                            (FPCore (R lambda1 lambda2 phi1 phi2)
                                                                                                             :precision binary64
                                                                                                             (* (acos (cos (- lambda1 lambda2))) R))
                                                                                                            double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                                                                                                            	return acos(cos((lambda1 - lambda2))) * 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 = acos(cos((lambda1 - lambda2))) * r
                                                                                                            end function
                                                                                                            
                                                                                                            public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                                                                                                            	return Math.acos(Math.cos((lambda1 - lambda2))) * R;
                                                                                                            }
                                                                                                            
                                                                                                            def code(R, lambda1, lambda2, phi1, phi2):
                                                                                                            	return math.acos(math.cos((lambda1 - lambda2))) * R
                                                                                                            
                                                                                                            function code(R, lambda1, lambda2, phi1, phi2)
                                                                                                            	return Float64(acos(cos(Float64(lambda1 - lambda2))) * R)
                                                                                                            end
                                                                                                            
                                                                                                            function tmp = code(R, lambda1, lambda2, phi1, phi2)
                                                                                                            	tmp = acos(cos((lambda1 - lambda2))) * R;
                                                                                                            end
                                                                                                            
                                                                                                            code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(N[ArcCos[N[Cos[N[(lambda1 - lambda2), $MachinePrecision]], $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]
                                                                                                            
                                                                                                            \begin{array}{l}
                                                                                                            
                                                                                                            \\
                                                                                                            \cos^{-1} \cos \left(\lambda_1 - \lambda_2\right) \cdot R
                                                                                                            \end{array}
                                                                                                            
                                                                                                            Derivation
                                                                                                            1. Initial program 73.6%

                                                                                                              \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                                                                            2. Add Preprocessing
                                                                                                            3. Taylor expanded in phi2 around 0

                                                                                                              \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)} \cdot R \]
                                                                                                            4. Step-by-step derivation
                                                                                                              1. Applied rewrites43.0%

                                                                                                                \[\leadsto \cos^{-1} \color{blue}{\left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right)} \cdot R \]
                                                                                                              2. Taylor expanded in phi1 around 0

                                                                                                                \[\leadsto \cos^{-1} \cos \left(\lambda_2 - \lambda_1\right) \cdot R \]
                                                                                                              3. Step-by-step derivation
                                                                                                                1. Applied rewrites27.0%

                                                                                                                  \[\leadsto \cos^{-1} \cos \left(\lambda_1 - \lambda_2\right) \cdot R \]
                                                                                                                2. Add Preprocessing

                                                                                                                Alternative 20: 17.7% accurate, 3.0× speedup?

                                                                                                                \[\begin{array}{l} \\ \cos^{-1} \cos \lambda_1 \cdot R \end{array} \]
                                                                                                                (FPCore (R lambda1 lambda2 phi1 phi2)
                                                                                                                 :precision binary64
                                                                                                                 (* (acos (cos lambda1)) R))
                                                                                                                double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                                                                                                                	return acos(cos(lambda1)) * 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 = acos(cos(lambda1)) * r
                                                                                                                end function
                                                                                                                
                                                                                                                public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
                                                                                                                	return Math.acos(Math.cos(lambda1)) * R;
                                                                                                                }
                                                                                                                
                                                                                                                def code(R, lambda1, lambda2, phi1, phi2):
                                                                                                                	return math.acos(math.cos(lambda1)) * R
                                                                                                                
                                                                                                                function code(R, lambda1, lambda2, phi1, phi2)
                                                                                                                	return Float64(acos(cos(lambda1)) * R)
                                                                                                                end
                                                                                                                
                                                                                                                function tmp = code(R, lambda1, lambda2, phi1, phi2)
                                                                                                                	tmp = acos(cos(lambda1)) * R;
                                                                                                                end
                                                                                                                
                                                                                                                code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(N[ArcCos[N[Cos[lambda1], $MachinePrecision]], $MachinePrecision] * R), $MachinePrecision]
                                                                                                                
                                                                                                                \begin{array}{l}
                                                                                                                
                                                                                                                \\
                                                                                                                \cos^{-1} \cos \lambda_1 \cdot R
                                                                                                                \end{array}
                                                                                                                
                                                                                                                Derivation
                                                                                                                1. Initial program 73.6%

                                                                                                                  \[\cos^{-1} \left(\sin \phi_1 \cdot \sin \phi_2 + \left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)\right) \cdot R \]
                                                                                                                2. Add Preprocessing
                                                                                                                3. Taylor expanded in phi2 around 0

                                                                                                                  \[\leadsto \cos^{-1} \color{blue}{\left(\cos \phi_1 \cdot \cos \left(\lambda_1 - \lambda_2\right)\right)} \cdot R \]
                                                                                                                4. Step-by-step derivation
                                                                                                                  1. Applied rewrites43.0%

                                                                                                                    \[\leadsto \cos^{-1} \color{blue}{\left(\cos \left(\lambda_2 - \lambda_1\right) \cdot \cos \phi_1\right)} \cdot R \]
                                                                                                                  2. Taylor expanded in phi1 around 0

                                                                                                                    \[\leadsto \cos^{-1} \cos \left(\lambda_2 - \lambda_1\right) \cdot R \]
                                                                                                                  3. Step-by-step derivation
                                                                                                                    1. Applied rewrites27.0%

                                                                                                                      \[\leadsto \cos^{-1} \cos \left(\lambda_1 - \lambda_2\right) \cdot R \]
                                                                                                                    2. Taylor expanded in lambda2 around 0

                                                                                                                      \[\leadsto \cos^{-1} \cos \lambda_1 \cdot R \]
                                                                                                                    3. Step-by-step derivation
                                                                                                                      1. Applied rewrites19.0%

                                                                                                                        \[\leadsto \cos^{-1} \cos \lambda_1 \cdot R \]
                                                                                                                      2. Add Preprocessing

                                                                                                                      Reproduce

                                                                                                                      ?
                                                                                                                      herbie shell --seed 2025021 
                                                                                                                      (FPCore (R lambda1 lambda2 phi1 phi2)
                                                                                                                        :name "Spherical law of cosines"
                                                                                                                        :precision binary64
                                                                                                                        (* (acos (+ (* (sin phi1) (sin phi2)) (* (* (cos phi1) (cos phi2)) (cos (- lambda1 lambda2))))) R))