Destination given bearing on a great circle

Percentage Accurate: 99.8% → 99.7%
Time: 15.6s
Alternatives: 14
Speedup: 1.2×

Specification

?
\[\begin{array}{l} \\ \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \end{array} \]
(FPCore (lambda1 phi1 phi2 delta theta)
 :precision binary64
 (+
  lambda1
  (atan2
   (* (* (sin theta) (sin delta)) (cos phi1))
   (-
    (cos delta)
    (*
     (sin phi1)
     (sin
      (asin
       (+
        (* (sin phi1) (cos delta))
        (* (* (cos phi1) (sin delta)) (cos theta))))))))))
double code(double lambda1, double phi1, double phi2, double delta, double theta) {
	return lambda1 + atan2(((sin(theta) * sin(delta)) * cos(phi1)), (cos(delta) - (sin(phi1) * sin(asin(((sin(phi1) * cos(delta)) + ((cos(phi1) * sin(delta)) * cos(theta))))))));
}
real(8) function code(lambda1, phi1, phi2, delta, theta)
    real(8), intent (in) :: lambda1
    real(8), intent (in) :: phi1
    real(8), intent (in) :: phi2
    real(8), intent (in) :: delta
    real(8), intent (in) :: theta
    code = lambda1 + atan2(((sin(theta) * sin(delta)) * cos(phi1)), (cos(delta) - (sin(phi1) * sin(asin(((sin(phi1) * cos(delta)) + ((cos(phi1) * sin(delta)) * cos(theta))))))))
end function
public static double code(double lambda1, double phi1, double phi2, double delta, double theta) {
	return lambda1 + Math.atan2(((Math.sin(theta) * Math.sin(delta)) * Math.cos(phi1)), (Math.cos(delta) - (Math.sin(phi1) * Math.sin(Math.asin(((Math.sin(phi1) * Math.cos(delta)) + ((Math.cos(phi1) * Math.sin(delta)) * Math.cos(theta))))))));
}
def code(lambda1, phi1, phi2, delta, theta):
	return lambda1 + math.atan2(((math.sin(theta) * math.sin(delta)) * math.cos(phi1)), (math.cos(delta) - (math.sin(phi1) * math.sin(math.asin(((math.sin(phi1) * math.cos(delta)) + ((math.cos(phi1) * math.sin(delta)) * math.cos(theta))))))))
function code(lambda1, phi1, phi2, delta, theta)
	return Float64(lambda1 + atan(Float64(Float64(sin(theta) * sin(delta)) * cos(phi1)), Float64(cos(delta) - Float64(sin(phi1) * sin(asin(Float64(Float64(sin(phi1) * cos(delta)) + Float64(Float64(cos(phi1) * sin(delta)) * cos(theta)))))))))
end
function tmp = code(lambda1, phi1, phi2, delta, theta)
	tmp = lambda1 + atan2(((sin(theta) * sin(delta)) * cos(phi1)), (cos(delta) - (sin(phi1) * sin(asin(((sin(phi1) * cos(delta)) + ((cos(phi1) * sin(delta)) * cos(theta))))))));
end
code[lambda1_, phi1_, phi2_, delta_, theta_] := N[(lambda1 + N[ArcTan[N[(N[(N[Sin[theta], $MachinePrecision] * N[Sin[delta], $MachinePrecision]), $MachinePrecision] * N[Cos[phi1], $MachinePrecision]), $MachinePrecision] / N[(N[Cos[delta], $MachinePrecision] - N[(N[Sin[phi1], $MachinePrecision] * N[Sin[N[ArcSin[N[(N[(N[Sin[phi1], $MachinePrecision] * N[Cos[delta], $MachinePrecision]), $MachinePrecision] + N[(N[(N[Cos[phi1], $MachinePrecision] * N[Sin[delta], $MachinePrecision]), $MachinePrecision] * N[Cos[theta], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}
\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 14 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: 99.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \end{array} \]
(FPCore (lambda1 phi1 phi2 delta theta)
 :precision binary64
 (+
  lambda1
  (atan2
   (* (* (sin theta) (sin delta)) (cos phi1))
   (-
    (cos delta)
    (*
     (sin phi1)
     (sin
      (asin
       (+
        (* (sin phi1) (cos delta))
        (* (* (cos phi1) (sin delta)) (cos theta))))))))))
double code(double lambda1, double phi1, double phi2, double delta, double theta) {
	return lambda1 + atan2(((sin(theta) * sin(delta)) * cos(phi1)), (cos(delta) - (sin(phi1) * sin(asin(((sin(phi1) * cos(delta)) + ((cos(phi1) * sin(delta)) * cos(theta))))))));
}
real(8) function code(lambda1, phi1, phi2, delta, theta)
    real(8), intent (in) :: lambda1
    real(8), intent (in) :: phi1
    real(8), intent (in) :: phi2
    real(8), intent (in) :: delta
    real(8), intent (in) :: theta
    code = lambda1 + atan2(((sin(theta) * sin(delta)) * cos(phi1)), (cos(delta) - (sin(phi1) * sin(asin(((sin(phi1) * cos(delta)) + ((cos(phi1) * sin(delta)) * cos(theta))))))))
end function
public static double code(double lambda1, double phi1, double phi2, double delta, double theta) {
	return lambda1 + Math.atan2(((Math.sin(theta) * Math.sin(delta)) * Math.cos(phi1)), (Math.cos(delta) - (Math.sin(phi1) * Math.sin(Math.asin(((Math.sin(phi1) * Math.cos(delta)) + ((Math.cos(phi1) * Math.sin(delta)) * Math.cos(theta))))))));
}
def code(lambda1, phi1, phi2, delta, theta):
	return lambda1 + math.atan2(((math.sin(theta) * math.sin(delta)) * math.cos(phi1)), (math.cos(delta) - (math.sin(phi1) * math.sin(math.asin(((math.sin(phi1) * math.cos(delta)) + ((math.cos(phi1) * math.sin(delta)) * math.cos(theta))))))))
function code(lambda1, phi1, phi2, delta, theta)
	return Float64(lambda1 + atan(Float64(Float64(sin(theta) * sin(delta)) * cos(phi1)), Float64(cos(delta) - Float64(sin(phi1) * sin(asin(Float64(Float64(sin(phi1) * cos(delta)) + Float64(Float64(cos(phi1) * sin(delta)) * cos(theta)))))))))
end
function tmp = code(lambda1, phi1, phi2, delta, theta)
	tmp = lambda1 + atan2(((sin(theta) * sin(delta)) * cos(phi1)), (cos(delta) - (sin(phi1) * sin(asin(((sin(phi1) * cos(delta)) + ((cos(phi1) * sin(delta)) * cos(theta))))))));
end
code[lambda1_, phi1_, phi2_, delta_, theta_] := N[(lambda1 + N[ArcTan[N[(N[(N[Sin[theta], $MachinePrecision] * N[Sin[delta], $MachinePrecision]), $MachinePrecision] * N[Cos[phi1], $MachinePrecision]), $MachinePrecision] / N[(N[Cos[delta], $MachinePrecision] - N[(N[Sin[phi1], $MachinePrecision] * N[Sin[N[ArcSin[N[(N[(N[Sin[phi1], $MachinePrecision] * N[Cos[delta], $MachinePrecision]), $MachinePrecision] + N[(N[(N[Cos[phi1], $MachinePrecision] * N[Sin[delta], $MachinePrecision]), $MachinePrecision] * N[Cos[theta], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}
\end{array}

Alternative 1: 99.7% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \sin \phi_1 \cdot \cos delta\\ t_2 := \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\\ \tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\mathsf{fma}\left(\mathsf{fma}\left({t\_1}^{2}, -\sin \phi_1, {t\_2}^{2} \cdot \sin \phi_1\right), {\left(t\_1 - t\_2\right)}^{-1}, \cos delta\right)} + \lambda_1 \end{array} \end{array} \]
(FPCore (lambda1 phi1 phi2 delta theta)
 :precision binary64
 (let* ((t_1 (* (sin phi1) (cos delta)))
        (t_2 (* (* (cos phi1) (sin delta)) (cos theta))))
   (+
    (atan2
     (* (cos phi1) (* (sin delta) (sin theta)))
     (fma
      (fma (pow t_1 2.0) (- (sin phi1)) (* (pow t_2 2.0) (sin phi1)))
      (pow (- t_1 t_2) -1.0)
      (cos delta)))
    lambda1)))
double code(double lambda1, double phi1, double phi2, double delta, double theta) {
	double t_1 = sin(phi1) * cos(delta);
	double t_2 = (cos(phi1) * sin(delta)) * cos(theta);
	return atan2((cos(phi1) * (sin(delta) * sin(theta))), fma(fma(pow(t_1, 2.0), -sin(phi1), (pow(t_2, 2.0) * sin(phi1))), pow((t_1 - t_2), -1.0), cos(delta))) + lambda1;
}
function code(lambda1, phi1, phi2, delta, theta)
	t_1 = Float64(sin(phi1) * cos(delta))
	t_2 = Float64(Float64(cos(phi1) * sin(delta)) * cos(theta))
	return Float64(atan(Float64(cos(phi1) * Float64(sin(delta) * sin(theta))), fma(fma((t_1 ^ 2.0), Float64(-sin(phi1)), Float64((t_2 ^ 2.0) * sin(phi1))), (Float64(t_1 - t_2) ^ -1.0), cos(delta))) + lambda1)
end
code[lambda1_, phi1_, phi2_, delta_, theta_] := Block[{t$95$1 = N[(N[Sin[phi1], $MachinePrecision] * N[Cos[delta], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[Cos[phi1], $MachinePrecision] * N[Sin[delta], $MachinePrecision]), $MachinePrecision] * N[Cos[theta], $MachinePrecision]), $MachinePrecision]}, N[(N[ArcTan[N[(N[Cos[phi1], $MachinePrecision] * N[(N[Sin[delta], $MachinePrecision] * N[Sin[theta], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(N[Power[t$95$1, 2.0], $MachinePrecision] * (-N[Sin[phi1], $MachinePrecision]) + N[(N[Power[t$95$2, 2.0], $MachinePrecision] * N[Sin[phi1], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Power[N[(t$95$1 - t$95$2), $MachinePrecision], -1.0], $MachinePrecision] + N[Cos[delta], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + lambda1), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \sin \phi_1 \cdot \cos delta\\
t_2 := \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\\
\tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\mathsf{fma}\left(\mathsf{fma}\left({t\_1}^{2}, -\sin \phi_1, {t\_2}^{2} \cdot \sin \phi_1\right), {\left(t\_1 - t\_2\right)}^{-1}, \cos delta\right)} + \lambda_1
\end{array}
\end{array}
Derivation
  1. Initial program 99.7%

    \[\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift--.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}} \]
    2. sub-negN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta + \left(\mathsf{neg}\left(\sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)\right)}} \]
    3. +-commutativeN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\left(\mathsf{neg}\left(\sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)\right) + \cos delta}} \]
  4. Applied rewrites99.7%

    \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\mathsf{fma}\left(\left(-\sin \phi_1\right) \cdot \left({\left(\cos delta \cdot \sin \phi_1\right)}^{2} - {\left(\cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{2}\right), {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)}} \]
  5. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\color{blue}{\left(-\sin \phi_1\right) \cdot \left({\left(\cos delta \cdot \sin \phi_1\right)}^{2} - {\left(\cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{2}\right)}, {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
    2. lift--.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\left(-\sin \phi_1\right) \cdot \color{blue}{\left({\left(\cos delta \cdot \sin \phi_1\right)}^{2} - {\left(\cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{2}\right)}, {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
    3. sub-negN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\left(-\sin \phi_1\right) \cdot \color{blue}{\left({\left(\cos delta \cdot \sin \phi_1\right)}^{2} + \left(\mathsf{neg}\left({\left(\cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{2}\right)\right)\right)}, {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
    4. distribute-rgt-inN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\color{blue}{{\left(\cos delta \cdot \sin \phi_1\right)}^{2} \cdot \left(-\sin \phi_1\right) + \left(\mathsf{neg}\left({\left(\cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{2}\right)\right) \cdot \left(-\sin \phi_1\right)}, {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
    5. lower-fma.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\color{blue}{\mathsf{fma}\left({\left(\cos delta \cdot \sin \phi_1\right)}^{2}, -\sin \phi_1, \left(\mathsf{neg}\left({\left(\cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{2}\right)\right) \cdot \left(-\sin \phi_1\right)\right)}, {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
    6. lower-*.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\mathsf{fma}\left({\left(\cos delta \cdot \sin \phi_1\right)}^{2}, -\sin \phi_1, \color{blue}{\left(\mathsf{neg}\left({\left(\cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{2}\right)\right) \cdot \left(-\sin \phi_1\right)}\right), {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
  6. Applied rewrites99.8%

    \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\color{blue}{\mathsf{fma}\left({\left(\cos delta \cdot \sin \phi_1\right)}^{2}, -\sin \phi_1, \left(-{\left(\left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}^{2}\right) \cdot \left(-\sin \phi_1\right)\right)}, {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
  7. Final simplification99.8%

    \[\leadsto \tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\mathsf{fma}\left(\mathsf{fma}\left({\left(\sin \phi_1 \cdot \cos delta\right)}^{2}, -\sin \phi_1, {\left(\left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}^{2} \cdot \sin \phi_1\right), {\left(\sin \phi_1 \cdot \cos delta - \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}^{-1}, \cos delta\right)} + \lambda_1 \]
  8. Add Preprocessing

Alternative 2: 99.7% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\\ \tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\mathsf{fma}\left(-\mathsf{fma}\left({t\_1}^{2}, -\sin \phi_1, {\sin \phi_1}^{3} \cdot {\cos delta}^{2}\right), {\left(\sin \phi_1 \cdot \cos delta - t\_1\right)}^{-1}, \cos delta\right)} + \lambda_1 \end{array} \end{array} \]
(FPCore (lambda1 phi1 phi2 delta theta)
 :precision binary64
 (let* ((t_1 (* (* (cos phi1) (sin delta)) (cos theta))))
   (+
    (atan2
     (* (cos phi1) (* (sin delta) (sin theta)))
     (fma
      (-
       (fma
        (pow t_1 2.0)
        (- (sin phi1))
        (* (pow (sin phi1) 3.0) (pow (cos delta) 2.0))))
      (pow (- (* (sin phi1) (cos delta)) t_1) -1.0)
      (cos delta)))
    lambda1)))
double code(double lambda1, double phi1, double phi2, double delta, double theta) {
	double t_1 = (cos(phi1) * sin(delta)) * cos(theta);
	return atan2((cos(phi1) * (sin(delta) * sin(theta))), fma(-fma(pow(t_1, 2.0), -sin(phi1), (pow(sin(phi1), 3.0) * pow(cos(delta), 2.0))), pow(((sin(phi1) * cos(delta)) - t_1), -1.0), cos(delta))) + lambda1;
}
function code(lambda1, phi1, phi2, delta, theta)
	t_1 = Float64(Float64(cos(phi1) * sin(delta)) * cos(theta))
	return Float64(atan(Float64(cos(phi1) * Float64(sin(delta) * sin(theta))), fma(Float64(-fma((t_1 ^ 2.0), Float64(-sin(phi1)), Float64((sin(phi1) ^ 3.0) * (cos(delta) ^ 2.0)))), (Float64(Float64(sin(phi1) * cos(delta)) - t_1) ^ -1.0), cos(delta))) + lambda1)
end
code[lambda1_, phi1_, phi2_, delta_, theta_] := Block[{t$95$1 = N[(N[(N[Cos[phi1], $MachinePrecision] * N[Sin[delta], $MachinePrecision]), $MachinePrecision] * N[Cos[theta], $MachinePrecision]), $MachinePrecision]}, N[(N[ArcTan[N[(N[Cos[phi1], $MachinePrecision] * N[(N[Sin[delta], $MachinePrecision] * N[Sin[theta], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[((-N[(N[Power[t$95$1, 2.0], $MachinePrecision] * (-N[Sin[phi1], $MachinePrecision]) + N[(N[Power[N[Sin[phi1], $MachinePrecision], 3.0], $MachinePrecision] * N[Power[N[Cos[delta], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]) * N[Power[N[(N[(N[Sin[phi1], $MachinePrecision] * N[Cos[delta], $MachinePrecision]), $MachinePrecision] - t$95$1), $MachinePrecision], -1.0], $MachinePrecision] + N[Cos[delta], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + lambda1), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\\
\tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\mathsf{fma}\left(-\mathsf{fma}\left({t\_1}^{2}, -\sin \phi_1, {\sin \phi_1}^{3} \cdot {\cos delta}^{2}\right), {\left(\sin \phi_1 \cdot \cos delta - t\_1\right)}^{-1}, \cos delta\right)} + \lambda_1
\end{array}
\end{array}
Derivation
  1. Initial program 99.7%

    \[\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift--.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}} \]
    2. sub-negN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta + \left(\mathsf{neg}\left(\sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)\right)}} \]
    3. +-commutativeN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\left(\mathsf{neg}\left(\sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)\right) + \cos delta}} \]
  4. Applied rewrites99.7%

    \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\mathsf{fma}\left(\left(-\sin \phi_1\right) \cdot \left({\left(\cos delta \cdot \sin \phi_1\right)}^{2} - {\left(\cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{2}\right), {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)}} \]
  5. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\color{blue}{\left(-\sin \phi_1\right) \cdot \left({\left(\cos delta \cdot \sin \phi_1\right)}^{2} - {\left(\cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{2}\right)}, {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
    2. lift--.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\left(-\sin \phi_1\right) \cdot \color{blue}{\left({\left(\cos delta \cdot \sin \phi_1\right)}^{2} - {\left(\cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{2}\right)}, {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
    3. sub-negN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\left(-\sin \phi_1\right) \cdot \color{blue}{\left({\left(\cos delta \cdot \sin \phi_1\right)}^{2} + \left(\mathsf{neg}\left({\left(\cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{2}\right)\right)\right)}, {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
    4. distribute-rgt-inN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\color{blue}{{\left(\cos delta \cdot \sin \phi_1\right)}^{2} \cdot \left(-\sin \phi_1\right) + \left(\mathsf{neg}\left({\left(\cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{2}\right)\right) \cdot \left(-\sin \phi_1\right)}, {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
    5. lower-fma.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\color{blue}{\mathsf{fma}\left({\left(\cos delta \cdot \sin \phi_1\right)}^{2}, -\sin \phi_1, \left(\mathsf{neg}\left({\left(\cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{2}\right)\right) \cdot \left(-\sin \phi_1\right)\right)}, {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
    6. lower-*.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\mathsf{fma}\left({\left(\cos delta \cdot \sin \phi_1\right)}^{2}, -\sin \phi_1, \color{blue}{\left(\mathsf{neg}\left({\left(\cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{2}\right)\right) \cdot \left(-\sin \phi_1\right)}\right), {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
  6. Applied rewrites99.8%

    \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\color{blue}{\mathsf{fma}\left({\left(\cos delta \cdot \sin \phi_1\right)}^{2}, -\sin \phi_1, \left(-{\left(\left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}^{2}\right) \cdot \left(-\sin \phi_1\right)\right)}, {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
  7. Step-by-step derivation
    1. lift-fma.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\color{blue}{{\left(\cos delta \cdot \sin \phi_1\right)}^{2} \cdot \left(-\sin \phi_1\right) + \left(-{\left(\left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}^{2}\right) \cdot \left(-\sin \phi_1\right)}, {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
    2. +-commutativeN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\color{blue}{\left(-{\left(\left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}^{2}\right) \cdot \left(-\sin \phi_1\right) + {\left(\cos delta \cdot \sin \phi_1\right)}^{2} \cdot \left(-\sin \phi_1\right)}, {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
    3. lift-*.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\color{blue}{\left(-{\left(\left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}^{2}\right) \cdot \left(-\sin \phi_1\right)} + {\left(\cos delta \cdot \sin \phi_1\right)}^{2} \cdot \left(-\sin \phi_1\right), {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
    4. lift-neg.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\color{blue}{\left(\mathsf{neg}\left({\left(\left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}^{2}\right)\right)} \cdot \left(-\sin \phi_1\right) + {\left(\cos delta \cdot \sin \phi_1\right)}^{2} \cdot \left(-\sin \phi_1\right), {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
    5. distribute-lft-neg-outN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\color{blue}{\left(\mathsf{neg}\left({\left(\left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}^{2} \cdot \left(-\sin \phi_1\right)\right)\right)} + {\left(\cos delta \cdot \sin \phi_1\right)}^{2} \cdot \left(-\sin \phi_1\right), {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
    6. lift-neg.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\left(\mathsf{neg}\left({\left(\left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}^{2} \cdot \left(-\sin \phi_1\right)\right)\right) + {\left(\cos delta \cdot \sin \phi_1\right)}^{2} \cdot \color{blue}{\left(\mathsf{neg}\left(\sin \phi_1\right)\right)}, {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
    7. distribute-rgt-neg-outN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\left(\mathsf{neg}\left({\left(\left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}^{2} \cdot \left(-\sin \phi_1\right)\right)\right) + \color{blue}{\left(\mathsf{neg}\left({\left(\cos delta \cdot \sin \phi_1\right)}^{2} \cdot \sin \phi_1\right)\right)}, {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
    8. distribute-neg-outN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\color{blue}{\mathsf{neg}\left(\left({\left(\left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}^{2} \cdot \left(-\sin \phi_1\right) + {\left(\cos delta \cdot \sin \phi_1\right)}^{2} \cdot \sin \phi_1\right)\right)}, {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
    9. lower-neg.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\color{blue}{-\left({\left(\left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}^{2} \cdot \left(-\sin \phi_1\right) + {\left(\cos delta \cdot \sin \phi_1\right)}^{2} \cdot \sin \phi_1\right)}, {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
  8. Applied rewrites99.8%

    \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\color{blue}{-\mathsf{fma}\left({\left(\left(\sin delta \cdot \cos \phi_1\right) \cdot \cos theta\right)}^{2}, -\sin \phi_1, {\cos delta}^{2} \cdot {\sin \phi_1}^{3}\right)}, {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)} \]
  9. Final simplification99.8%

    \[\leadsto \tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\mathsf{fma}\left(-\mathsf{fma}\left({\left(\left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}^{2}, -\sin \phi_1, {\sin \phi_1}^{3} \cdot {\cos delta}^{2}\right), {\left(\sin \phi_1 \cdot \cos delta - \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}^{-1}, \cos delta\right)} + \lambda_1 \]
  10. Add Preprocessing

Alternative 3: 99.7% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\\ t_2 := \sin \phi_1 \cdot \cos delta\\ \tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\mathsf{fma}\left(\left({t\_1}^{2} - {t\_2}^{2}\right) \cdot \sin \phi_1, {\left(t\_2 - t\_1\right)}^{-1}, \cos delta\right)} + \lambda_1 \end{array} \end{array} \]
(FPCore (lambda1 phi1 phi2 delta theta)
 :precision binary64
 (let* ((t_1 (* (* (cos phi1) (sin delta)) (cos theta)))
        (t_2 (* (sin phi1) (cos delta))))
   (+
    (atan2
     (* (cos phi1) (* (sin delta) (sin theta)))
     (fma
      (* (- (pow t_1 2.0) (pow t_2 2.0)) (sin phi1))
      (pow (- t_2 t_1) -1.0)
      (cos delta)))
    lambda1)))
double code(double lambda1, double phi1, double phi2, double delta, double theta) {
	double t_1 = (cos(phi1) * sin(delta)) * cos(theta);
	double t_2 = sin(phi1) * cos(delta);
	return atan2((cos(phi1) * (sin(delta) * sin(theta))), fma(((pow(t_1, 2.0) - pow(t_2, 2.0)) * sin(phi1)), pow((t_2 - t_1), -1.0), cos(delta))) + lambda1;
}
function code(lambda1, phi1, phi2, delta, theta)
	t_1 = Float64(Float64(cos(phi1) * sin(delta)) * cos(theta))
	t_2 = Float64(sin(phi1) * cos(delta))
	return Float64(atan(Float64(cos(phi1) * Float64(sin(delta) * sin(theta))), fma(Float64(Float64((t_1 ^ 2.0) - (t_2 ^ 2.0)) * sin(phi1)), (Float64(t_2 - t_1) ^ -1.0), cos(delta))) + lambda1)
end
code[lambda1_, phi1_, phi2_, delta_, theta_] := Block[{t$95$1 = N[(N[(N[Cos[phi1], $MachinePrecision] * N[Sin[delta], $MachinePrecision]), $MachinePrecision] * N[Cos[theta], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[Sin[phi1], $MachinePrecision] * N[Cos[delta], $MachinePrecision]), $MachinePrecision]}, N[(N[ArcTan[N[(N[Cos[phi1], $MachinePrecision] * N[(N[Sin[delta], $MachinePrecision] * N[Sin[theta], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(N[Power[t$95$1, 2.0], $MachinePrecision] - N[Power[t$95$2, 2.0], $MachinePrecision]), $MachinePrecision] * N[Sin[phi1], $MachinePrecision]), $MachinePrecision] * N[Power[N[(t$95$2 - t$95$1), $MachinePrecision], -1.0], $MachinePrecision] + N[Cos[delta], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + lambda1), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\\
t_2 := \sin \phi_1 \cdot \cos delta\\
\tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\mathsf{fma}\left(\left({t\_1}^{2} - {t\_2}^{2}\right) \cdot \sin \phi_1, {\left(t\_2 - t\_1\right)}^{-1}, \cos delta\right)} + \lambda_1
\end{array}
\end{array}
Derivation
  1. Initial program 99.7%

    \[\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift--.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}} \]
    2. sub-negN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta + \left(\mathsf{neg}\left(\sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)\right)}} \]
    3. +-commutativeN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\left(\mathsf{neg}\left(\sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)\right) + \cos delta}} \]
  4. Applied rewrites99.7%

    \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\mathsf{fma}\left(\left(-\sin \phi_1\right) \cdot \left({\left(\cos delta \cdot \sin \phi_1\right)}^{2} - {\left(\cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{2}\right), {\left(\cos delta \cdot \sin \phi_1 - \cos theta \cdot \left(\sin delta \cdot \cos \phi_1\right)\right)}^{-1}, \cos delta\right)}} \]
  5. Final simplification99.7%

    \[\leadsto \tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\mathsf{fma}\left(\left({\left(\left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}^{2} - {\left(\sin \phi_1 \cdot \cos delta\right)}^{2}\right) \cdot \sin \phi_1, {\left(\sin \phi_1 \cdot \cos delta - \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}^{-1}, \cos delta\right)} + \lambda_1 \]
  6. Add Preprocessing

Alternative 4: 99.7% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \cos \phi_1 \cdot \sin delta\\ \tan^{-1}_* \frac{t\_1 \cdot \sin theta}{\cos delta - \frac{1}{\frac{1}{\mathsf{fma}\left(\cos theta, t\_1, \sin \phi_1 \cdot \cos delta\right) \cdot \sin \phi_1}}} + \lambda_1 \end{array} \end{array} \]
(FPCore (lambda1 phi1 phi2 delta theta)
 :precision binary64
 (let* ((t_1 (* (cos phi1) (sin delta))))
   (+
    (atan2
     (* t_1 (sin theta))
     (-
      (cos delta)
      (/
       1.0
       (/
        1.0
        (* (fma (cos theta) t_1 (* (sin phi1) (cos delta))) (sin phi1))))))
    lambda1)))
double code(double lambda1, double phi1, double phi2, double delta, double theta) {
	double t_1 = cos(phi1) * sin(delta);
	return atan2((t_1 * sin(theta)), (cos(delta) - (1.0 / (1.0 / (fma(cos(theta), t_1, (sin(phi1) * cos(delta))) * sin(phi1)))))) + lambda1;
}
function code(lambda1, phi1, phi2, delta, theta)
	t_1 = Float64(cos(phi1) * sin(delta))
	return Float64(atan(Float64(t_1 * sin(theta)), Float64(cos(delta) - Float64(1.0 / Float64(1.0 / Float64(fma(cos(theta), t_1, Float64(sin(phi1) * cos(delta))) * sin(phi1)))))) + lambda1)
end
code[lambda1_, phi1_, phi2_, delta_, theta_] := Block[{t$95$1 = N[(N[Cos[phi1], $MachinePrecision] * N[Sin[delta], $MachinePrecision]), $MachinePrecision]}, N[(N[ArcTan[N[(t$95$1 * N[Sin[theta], $MachinePrecision]), $MachinePrecision] / N[(N[Cos[delta], $MachinePrecision] - N[(1.0 / N[(1.0 / N[(N[(N[Cos[theta], $MachinePrecision] * t$95$1 + N[(N[Sin[phi1], $MachinePrecision] * N[Cos[delta], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Sin[phi1], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + lambda1), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \cos \phi_1 \cdot \sin delta\\
\tan^{-1}_* \frac{t\_1 \cdot \sin theta}{\cos delta - \frac{1}{\frac{1}{\mathsf{fma}\left(\cos theta, t\_1, \sin \phi_1 \cdot \cos delta\right) \cdot \sin \phi_1}}} + \lambda_1
\end{array}
\end{array}
Derivation
  1. Initial program 99.7%

    \[\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}} \]
    2. lift-sin.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\sin \phi_1} \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
    3. lift-sin.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \color{blue}{\sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}} \]
    4. sin-multN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}{2}}} \]
    5. clear-numN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{1}{\frac{2}{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}}}} \]
    6. lower-/.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{1}{\frac{2}{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}}}} \]
    7. clear-numN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \frac{1}{\color{blue}{\frac{1}{\frac{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}{2}}}}} \]
  4. Applied rewrites99.7%

    \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{1}{\frac{1}{\mathsf{fma}\left(\cos theta, \sin delta \cdot \cos \phi_1, \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1}}}} \]
  5. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}}{\cos delta - \frac{1}{\frac{1}{\mathsf{fma}\left(\cos theta, \sin delta \cdot \cos \phi_1, \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1}}} \]
    2. lift-*.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\left(\sin theta \cdot \sin delta\right)} \cdot \cos \phi_1}{\cos delta - \frac{1}{\frac{1}{\mathsf{fma}\left(\cos theta, \sin delta \cdot \cos \phi_1, \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1}}} \]
    3. associate-*l*N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin theta \cdot \left(\sin delta \cdot \cos \phi_1\right)}}{\cos delta - \frac{1}{\frac{1}{\mathsf{fma}\left(\cos theta, \sin delta \cdot \cos \phi_1, \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1}}} \]
    4. lift-*.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\sin theta \cdot \color{blue}{\left(\sin delta \cdot \cos \phi_1\right)}}{\cos delta - \frac{1}{\frac{1}{\mathsf{fma}\left(\cos theta, \sin delta \cdot \cos \phi_1, \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1}}} \]
    5. *-commutativeN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\left(\sin delta \cdot \cos \phi_1\right) \cdot \sin theta}}{\cos delta - \frac{1}{\frac{1}{\mathsf{fma}\left(\cos theta, \sin delta \cdot \cos \phi_1, \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1}}} \]
    6. lower-*.f6499.7

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\left(\sin delta \cdot \cos \phi_1\right) \cdot \sin theta}}{\cos delta - \frac{1}{\frac{1}{\mathsf{fma}\left(\cos theta, \sin delta \cdot \cos \phi_1, \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1}}} \]
    7. lift-*.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\left(\sin delta \cdot \cos \phi_1\right)} \cdot \sin theta}{\cos delta - \frac{1}{\frac{1}{\mathsf{fma}\left(\cos theta, \sin delta \cdot \cos \phi_1, \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1}}} \]
    8. *-commutativeN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\left(\cos \phi_1 \cdot \sin delta\right)} \cdot \sin theta}{\cos delta - \frac{1}{\frac{1}{\mathsf{fma}\left(\cos theta, \sin delta \cdot \cos \phi_1, \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1}}} \]
    9. lower-*.f6499.7

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\left(\cos \phi_1 \cdot \sin delta\right)} \cdot \sin theta}{\cos delta - \frac{1}{\frac{1}{\mathsf{fma}\left(\cos theta, \sin delta \cdot \cos \phi_1, \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1}}} \]
  6. Applied rewrites99.7%

    \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\left(\cos \phi_1 \cdot \sin delta\right) \cdot \sin theta}}{\cos delta - \frac{1}{\frac{1}{\mathsf{fma}\left(\cos theta, \sin delta \cdot \cos \phi_1, \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1}}} \]
  7. Final simplification99.7%

    \[\leadsto \tan^{-1}_* \frac{\left(\cos \phi_1 \cdot \sin delta\right) \cdot \sin theta}{\cos delta - \frac{1}{\frac{1}{\mathsf{fma}\left(\cos theta, \cos \phi_1 \cdot \sin delta, \sin \phi_1 \cdot \cos delta\right) \cdot \sin \phi_1}}} + \lambda_1 \]
  8. Add Preprocessing

Alternative 5: 99.8% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(\tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\mathsf{fma}\left(\mathsf{fma}\left(\cos delta, \sin \phi_1, \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right), -\sin \phi_1, \cos delta\right)}, 1, \lambda_1\right) \end{array} \]
(FPCore (lambda1 phi1 phi2 delta theta)
 :precision binary64
 (fma
  (atan2
   (* (cos phi1) (* (sin delta) (sin theta)))
   (fma
    (fma (cos delta) (sin phi1) (* (* (cos phi1) (sin delta)) (cos theta)))
    (- (sin phi1))
    (cos delta)))
  1.0
  lambda1))
double code(double lambda1, double phi1, double phi2, double delta, double theta) {
	return fma(atan2((cos(phi1) * (sin(delta) * sin(theta))), fma(fma(cos(delta), sin(phi1), ((cos(phi1) * sin(delta)) * cos(theta))), -sin(phi1), cos(delta))), 1.0, lambda1);
}
function code(lambda1, phi1, phi2, delta, theta)
	return fma(atan(Float64(cos(phi1) * Float64(sin(delta) * sin(theta))), fma(fma(cos(delta), sin(phi1), Float64(Float64(cos(phi1) * sin(delta)) * cos(theta))), Float64(-sin(phi1)), cos(delta))), 1.0, lambda1)
end
code[lambda1_, phi1_, phi2_, delta_, theta_] := N[(N[ArcTan[N[(N[Cos[phi1], $MachinePrecision] * N[(N[Sin[delta], $MachinePrecision] * N[Sin[theta], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(N[Cos[delta], $MachinePrecision] * N[Sin[phi1], $MachinePrecision] + N[(N[(N[Cos[phi1], $MachinePrecision] * N[Sin[delta], $MachinePrecision]), $MachinePrecision] * N[Cos[theta], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * (-N[Sin[phi1], $MachinePrecision]) + N[Cos[delta], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 1.0 + lambda1), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(\tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\mathsf{fma}\left(\mathsf{fma}\left(\cos delta, \sin \phi_1, \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right), -\sin \phi_1, \cos delta\right)}, 1, \lambda_1\right)
\end{array}
Derivation
  1. Initial program 99.7%

    \[\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}} \]
    2. lift-sin.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\sin \phi_1} \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
    3. lift-sin.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \color{blue}{\sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}} \]
    4. sin-multN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}{2}}} \]
    5. clear-numN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{1}{\frac{2}{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}}}} \]
    6. lower-/.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{1}{\frac{2}{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}}}} \]
    7. clear-numN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \frac{1}{\color{blue}{\frac{1}{\frac{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}{2}}}}} \]
  4. Applied rewrites99.7%

    \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{1}{\frac{1}{\mathsf{fma}\left(\cos theta, \sin delta \cdot \cos \phi_1, \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1}}}} \]
  5. Taylor expanded in lambda1 around inf

    \[\leadsto \color{blue}{\lambda_1 \cdot \left(1 + \frac{\tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\cos delta - \sin \phi_1 \cdot \left(\cos delta \cdot \sin \phi_1 + \cos \phi_1 \cdot \left(\cos theta \cdot \sin delta\right)\right)}}{\lambda_1}\right)} \]
  6. Step-by-step derivation
    1. +-commutativeN/A

      \[\leadsto \lambda_1 \cdot \color{blue}{\left(\frac{\tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\cos delta - \sin \phi_1 \cdot \left(\cos delta \cdot \sin \phi_1 + \cos \phi_1 \cdot \left(\cos theta \cdot \sin delta\right)\right)}}{\lambda_1} + 1\right)} \]
    2. distribute-rgt-inN/A

      \[\leadsto \color{blue}{\frac{\tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\cos delta - \sin \phi_1 \cdot \left(\cos delta \cdot \sin \phi_1 + \cos \phi_1 \cdot \left(\cos theta \cdot \sin delta\right)\right)}}{\lambda_1} \cdot \lambda_1 + 1 \cdot \lambda_1} \]
    3. *-lft-identityN/A

      \[\leadsto \frac{\tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\cos delta - \sin \phi_1 \cdot \left(\cos delta \cdot \sin \phi_1 + \cos \phi_1 \cdot \left(\cos theta \cdot \sin delta\right)\right)}}{\lambda_1} \cdot \lambda_1 + \color{blue}{\lambda_1} \]
    4. lower-fma.f64N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\cos delta - \sin \phi_1 \cdot \left(\cos delta \cdot \sin \phi_1 + \cos \phi_1 \cdot \left(\cos theta \cdot \sin delta\right)\right)}}{\lambda_1}, \lambda_1, \lambda_1\right)} \]
  7. Applied rewrites99.7%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \mathsf{fma}\left(\cos theta \cdot \sin delta, \cos \phi_1, \sin \phi_1 \cdot \cos delta\right) \cdot \sin \phi_1}}{\lambda_1}, \lambda_1, \lambda_1\right)} \]
  8. Applied rewrites99.7%

    \[\leadsto \mathsf{fma}\left(\tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\mathsf{fma}\left(\mathsf{fma}\left(\cos delta, \sin \phi_1, \cos theta \cdot \left(\cos \phi_1 \cdot \sin delta\right)\right), -\sin \phi_1, \cos delta\right)}, \color{blue}{1}, \lambda_1\right) \]
  9. Final simplification99.7%

    \[\leadsto \mathsf{fma}\left(\tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\mathsf{fma}\left(\mathsf{fma}\left(\cos delta, \sin \phi_1, \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right), -\sin \phi_1, \cos delta\right)}, 1, \lambda_1\right) \]
  10. Add Preprocessing

Alternative 6: 99.8% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\mathsf{fma}\left(\mathsf{fma}\left(\cos theta, \cos \phi_1 \cdot \sin delta, \sin \phi_1 \cdot \cos delta\right), -\sin \phi_1, \cos delta\right)} + \lambda_1 \end{array} \]
(FPCore (lambda1 phi1 phi2 delta theta)
 :precision binary64
 (+
  (atan2
   (* (cos phi1) (* (sin delta) (sin theta)))
   (fma
    (fma (cos theta) (* (cos phi1) (sin delta)) (* (sin phi1) (cos delta)))
    (- (sin phi1))
    (cos delta)))
  lambda1))
double code(double lambda1, double phi1, double phi2, double delta, double theta) {
	return atan2((cos(phi1) * (sin(delta) * sin(theta))), fma(fma(cos(theta), (cos(phi1) * sin(delta)), (sin(phi1) * cos(delta))), -sin(phi1), cos(delta))) + lambda1;
}
function code(lambda1, phi1, phi2, delta, theta)
	return Float64(atan(Float64(cos(phi1) * Float64(sin(delta) * sin(theta))), fma(fma(cos(theta), Float64(cos(phi1) * sin(delta)), Float64(sin(phi1) * cos(delta))), Float64(-sin(phi1)), cos(delta))) + lambda1)
end
code[lambda1_, phi1_, phi2_, delta_, theta_] := N[(N[ArcTan[N[(N[Cos[phi1], $MachinePrecision] * N[(N[Sin[delta], $MachinePrecision] * N[Sin[theta], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(N[Cos[theta], $MachinePrecision] * N[(N[Cos[phi1], $MachinePrecision] * N[Sin[delta], $MachinePrecision]), $MachinePrecision] + N[(N[Sin[phi1], $MachinePrecision] * N[Cos[delta], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * (-N[Sin[phi1], $MachinePrecision]) + N[Cos[delta], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + lambda1), $MachinePrecision]
\begin{array}{l}

\\
\tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\mathsf{fma}\left(\mathsf{fma}\left(\cos theta, \cos \phi_1 \cdot \sin delta, \sin \phi_1 \cdot \cos delta\right), -\sin \phi_1, \cos delta\right)} + \lambda_1
\end{array}
Derivation
  1. Initial program 99.7%

    \[\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift--.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}} \]
    2. sub-negN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta + \left(\mathsf{neg}\left(\sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)\right)}} \]
    3. +-commutativeN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\left(\mathsf{neg}\left(\sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)\right) + \cos delta}} \]
  4. Applied rewrites99.7%

    \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\cos theta, \sin delta \cdot \cos \phi_1, \cos delta \cdot \sin \phi_1\right), -\sin \phi_1, \cos delta\right)}} \]
  5. Final simplification99.7%

    \[\leadsto \tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\mathsf{fma}\left(\mathsf{fma}\left(\cos theta, \cos \phi_1 \cdot \sin delta, \sin \phi_1 \cdot \cos delta\right), -\sin \phi_1, \cos delta\right)} + \lambda_1 \]
  6. Add Preprocessing

Alternative 7: 99.8% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\cos delta - \mathsf{fma}\left(\cos theta \cdot \sin delta, \cos \phi_1, \sin \phi_1 \cdot \cos delta\right) \cdot \sin \phi_1} + \lambda_1 \end{array} \]
(FPCore (lambda1 phi1 phi2 delta theta)
 :precision binary64
 (+
  (atan2
   (* (cos phi1) (* (sin delta) (sin theta)))
   (-
    (cos delta)
    (*
     (fma (* (cos theta) (sin delta)) (cos phi1) (* (sin phi1) (cos delta)))
     (sin phi1))))
  lambda1))
double code(double lambda1, double phi1, double phi2, double delta, double theta) {
	return atan2((cos(phi1) * (sin(delta) * sin(theta))), (cos(delta) - (fma((cos(theta) * sin(delta)), cos(phi1), (sin(phi1) * cos(delta))) * sin(phi1)))) + lambda1;
}
function code(lambda1, phi1, phi2, delta, theta)
	return Float64(atan(Float64(cos(phi1) * Float64(sin(delta) * sin(theta))), Float64(cos(delta) - Float64(fma(Float64(cos(theta) * sin(delta)), cos(phi1), Float64(sin(phi1) * cos(delta))) * sin(phi1)))) + lambda1)
end
code[lambda1_, phi1_, phi2_, delta_, theta_] := N[(N[ArcTan[N[(N[Cos[phi1], $MachinePrecision] * N[(N[Sin[delta], $MachinePrecision] * N[Sin[theta], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[Cos[delta], $MachinePrecision] - N[(N[(N[(N[Cos[theta], $MachinePrecision] * N[Sin[delta], $MachinePrecision]), $MachinePrecision] * N[Cos[phi1], $MachinePrecision] + N[(N[Sin[phi1], $MachinePrecision] * N[Cos[delta], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Sin[phi1], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + lambda1), $MachinePrecision]
\begin{array}{l}

\\
\tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\cos delta - \mathsf{fma}\left(\cos theta \cdot \sin delta, \cos \phi_1, \sin \phi_1 \cdot \cos delta\right) \cdot \sin \phi_1} + \lambda_1
\end{array}
Derivation
  1. Initial program 99.7%

    \[\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
  2. Add Preprocessing
  3. Taylor expanded in theta around inf

    \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\sin \phi_1 \cdot \left(\cos delta \cdot \sin \phi_1 + \cos \phi_1 \cdot \left(\cos theta \cdot \sin delta\right)\right)}} \]
  4. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\left(\cos delta \cdot \sin \phi_1 + \cos \phi_1 \cdot \left(\cos theta \cdot \sin delta\right)\right) \cdot \sin \phi_1}} \]
    2. lower-*.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\left(\cos delta \cdot \sin \phi_1 + \cos \phi_1 \cdot \left(\cos theta \cdot \sin delta\right)\right) \cdot \sin \phi_1}} \]
    3. +-commutativeN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\left(\cos \phi_1 \cdot \left(\cos theta \cdot \sin delta\right) + \cos delta \cdot \sin \phi_1\right)} \cdot \sin \phi_1} \]
    4. *-commutativeN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \left(\color{blue}{\left(\cos theta \cdot \sin delta\right) \cdot \cos \phi_1} + \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1} \]
    5. lower-fma.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\mathsf{fma}\left(\cos theta \cdot \sin delta, \cos \phi_1, \cos delta \cdot \sin \phi_1\right)} \cdot \sin \phi_1} \]
    6. lower-*.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \mathsf{fma}\left(\color{blue}{\cos theta \cdot \sin delta}, \cos \phi_1, \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1} \]
    7. lower-cos.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \mathsf{fma}\left(\color{blue}{\cos theta} \cdot \sin delta, \cos \phi_1, \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1} \]
    8. lower-sin.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \mathsf{fma}\left(\cos theta \cdot \color{blue}{\sin delta}, \cos \phi_1, \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1} \]
    9. lower-cos.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \mathsf{fma}\left(\cos theta \cdot \sin delta, \color{blue}{\cos \phi_1}, \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1} \]
    10. *-commutativeN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \mathsf{fma}\left(\cos theta \cdot \sin delta, \cos \phi_1, \color{blue}{\sin \phi_1 \cdot \cos delta}\right) \cdot \sin \phi_1} \]
    11. lower-*.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \mathsf{fma}\left(\cos theta \cdot \sin delta, \cos \phi_1, \color{blue}{\sin \phi_1 \cdot \cos delta}\right) \cdot \sin \phi_1} \]
    12. lower-sin.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \mathsf{fma}\left(\cos theta \cdot \sin delta, \cos \phi_1, \color{blue}{\sin \phi_1} \cdot \cos delta\right) \cdot \sin \phi_1} \]
    13. lower-cos.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \mathsf{fma}\left(\cos theta \cdot \sin delta, \cos \phi_1, \sin \phi_1 \cdot \color{blue}{\cos delta}\right) \cdot \sin \phi_1} \]
    14. lower-sin.f6499.7

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \mathsf{fma}\left(\cos theta \cdot \sin delta, \cos \phi_1, \sin \phi_1 \cdot \cos delta\right) \cdot \color{blue}{\sin \phi_1}} \]
  5. Applied rewrites99.7%

    \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\mathsf{fma}\left(\cos theta \cdot \sin delta, \cos \phi_1, \sin \phi_1 \cdot \cos delta\right) \cdot \sin \phi_1}} \]
  6. Final simplification99.7%

    \[\leadsto \tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\cos delta - \mathsf{fma}\left(\cos theta \cdot \sin delta, \cos \phi_1, \sin \phi_1 \cdot \cos delta\right) \cdot \sin \phi_1} + \lambda_1 \]
  7. Add Preprocessing

Alternative 8: 94.8% accurate, 1.3× speedup?

\[\begin{array}{l} \\ \tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\cos delta - \mathsf{fma}\left(\sin \phi_1, \cos delta, \cos \phi_1 \cdot \sin delta\right) \cdot \sin \phi_1} + \lambda_1 \end{array} \]
(FPCore (lambda1 phi1 phi2 delta theta)
 :precision binary64
 (+
  (atan2
   (* (cos phi1) (* (sin delta) (sin theta)))
   (-
    (cos delta)
    (* (fma (sin phi1) (cos delta) (* (cos phi1) (sin delta))) (sin phi1))))
  lambda1))
double code(double lambda1, double phi1, double phi2, double delta, double theta) {
	return atan2((cos(phi1) * (sin(delta) * sin(theta))), (cos(delta) - (fma(sin(phi1), cos(delta), (cos(phi1) * sin(delta))) * sin(phi1)))) + lambda1;
}
function code(lambda1, phi1, phi2, delta, theta)
	return Float64(atan(Float64(cos(phi1) * Float64(sin(delta) * sin(theta))), Float64(cos(delta) - Float64(fma(sin(phi1), cos(delta), Float64(cos(phi1) * sin(delta))) * sin(phi1)))) + lambda1)
end
code[lambda1_, phi1_, phi2_, delta_, theta_] := N[(N[ArcTan[N[(N[Cos[phi1], $MachinePrecision] * N[(N[Sin[delta], $MachinePrecision] * N[Sin[theta], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[Cos[delta], $MachinePrecision] - N[(N[(N[Sin[phi1], $MachinePrecision] * N[Cos[delta], $MachinePrecision] + N[(N[Cos[phi1], $MachinePrecision] * N[Sin[delta], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Sin[phi1], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + lambda1), $MachinePrecision]
\begin{array}{l}

\\
\tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\cos delta - \mathsf{fma}\left(\sin \phi_1, \cos delta, \cos \phi_1 \cdot \sin delta\right) \cdot \sin \phi_1} + \lambda_1
\end{array}
Derivation
  1. Initial program 99.7%

    \[\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
  2. Add Preprocessing
  3. Taylor expanded in theta around 0

    \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\sin \phi_1 \cdot \left(\cos delta \cdot \sin \phi_1 + \cos \phi_1 \cdot \sin delta\right)}} \]
  4. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\left(\cos delta \cdot \sin \phi_1 + \cos \phi_1 \cdot \sin delta\right) \cdot \sin \phi_1}} \]
    2. lower-*.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\left(\cos delta \cdot \sin \phi_1 + \cos \phi_1 \cdot \sin delta\right) \cdot \sin \phi_1}} \]
    3. *-commutativeN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \left(\color{blue}{\sin \phi_1 \cdot \cos delta} + \cos \phi_1 \cdot \sin delta\right) \cdot \sin \phi_1} \]
    4. lower-fma.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\mathsf{fma}\left(\sin \phi_1, \cos delta, \cos \phi_1 \cdot \sin delta\right)} \cdot \sin \phi_1} \]
    5. lower-sin.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \mathsf{fma}\left(\color{blue}{\sin \phi_1}, \cos delta, \cos \phi_1 \cdot \sin delta\right) \cdot \sin \phi_1} \]
    6. lower-cos.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \mathsf{fma}\left(\sin \phi_1, \color{blue}{\cos delta}, \cos \phi_1 \cdot \sin delta\right) \cdot \sin \phi_1} \]
    7. *-commutativeN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \mathsf{fma}\left(\sin \phi_1, \cos delta, \color{blue}{\sin delta \cdot \cos \phi_1}\right) \cdot \sin \phi_1} \]
    8. lower-*.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \mathsf{fma}\left(\sin \phi_1, \cos delta, \color{blue}{\sin delta \cdot \cos \phi_1}\right) \cdot \sin \phi_1} \]
    9. lower-sin.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \mathsf{fma}\left(\sin \phi_1, \cos delta, \color{blue}{\sin delta} \cdot \cos \phi_1\right) \cdot \sin \phi_1} \]
    10. lower-cos.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \mathsf{fma}\left(\sin \phi_1, \cos delta, \sin delta \cdot \color{blue}{\cos \phi_1}\right) \cdot \sin \phi_1} \]
    11. lower-sin.f6495.4

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \mathsf{fma}\left(\sin \phi_1, \cos delta, \sin delta \cdot \cos \phi_1\right) \cdot \color{blue}{\sin \phi_1}} \]
  5. Applied rewrites95.4%

    \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\mathsf{fma}\left(\sin \phi_1, \cos delta, \sin delta \cdot \cos \phi_1\right) \cdot \sin \phi_1}} \]
  6. Final simplification95.4%

    \[\leadsto \tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\cos delta - \mathsf{fma}\left(\sin \phi_1, \cos delta, \cos \phi_1 \cdot \sin delta\right) \cdot \sin \phi_1} + \lambda_1 \]
  7. Add Preprocessing

Alternative 9: 92.3% accurate, 2.1× speedup?

\[\begin{array}{l} \\ \tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\cos delta - \left(0.5 - \cos \left(\phi_1 + \phi_1\right) \cdot 0.5\right)} + \lambda_1 \end{array} \]
(FPCore (lambda1 phi1 phi2 delta theta)
 :precision binary64
 (+
  (atan2
   (* (cos phi1) (* (sin delta) (sin theta)))
   (- (cos delta) (- 0.5 (* (cos (+ phi1 phi1)) 0.5))))
  lambda1))
double code(double lambda1, double phi1, double phi2, double delta, double theta) {
	return atan2((cos(phi1) * (sin(delta) * sin(theta))), (cos(delta) - (0.5 - (cos((phi1 + phi1)) * 0.5)))) + lambda1;
}
real(8) function code(lambda1, phi1, phi2, delta, theta)
    real(8), intent (in) :: lambda1
    real(8), intent (in) :: phi1
    real(8), intent (in) :: phi2
    real(8), intent (in) :: delta
    real(8), intent (in) :: theta
    code = atan2((cos(phi1) * (sin(delta) * sin(theta))), (cos(delta) - (0.5d0 - (cos((phi1 + phi1)) * 0.5d0)))) + lambda1
end function
public static double code(double lambda1, double phi1, double phi2, double delta, double theta) {
	return Math.atan2((Math.cos(phi1) * (Math.sin(delta) * Math.sin(theta))), (Math.cos(delta) - (0.5 - (Math.cos((phi1 + phi1)) * 0.5)))) + lambda1;
}
def code(lambda1, phi1, phi2, delta, theta):
	return math.atan2((math.cos(phi1) * (math.sin(delta) * math.sin(theta))), (math.cos(delta) - (0.5 - (math.cos((phi1 + phi1)) * 0.5)))) + lambda1
function code(lambda1, phi1, phi2, delta, theta)
	return Float64(atan(Float64(cos(phi1) * Float64(sin(delta) * sin(theta))), Float64(cos(delta) - Float64(0.5 - Float64(cos(Float64(phi1 + phi1)) * 0.5)))) + lambda1)
end
function tmp = code(lambda1, phi1, phi2, delta, theta)
	tmp = atan2((cos(phi1) * (sin(delta) * sin(theta))), (cos(delta) - (0.5 - (cos((phi1 + phi1)) * 0.5)))) + lambda1;
end
code[lambda1_, phi1_, phi2_, delta_, theta_] := N[(N[ArcTan[N[(N[Cos[phi1], $MachinePrecision] * N[(N[Sin[delta], $MachinePrecision] * N[Sin[theta], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[Cos[delta], $MachinePrecision] - N[(0.5 - N[(N[Cos[N[(phi1 + phi1), $MachinePrecision]], $MachinePrecision] * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + lambda1), $MachinePrecision]
\begin{array}{l}

\\
\tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\cos delta - \left(0.5 - \cos \left(\phi_1 + \phi_1\right) \cdot 0.5\right)} + \lambda_1
\end{array}
Derivation
  1. Initial program 99.7%

    \[\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}} \]
    2. lift-sin.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\sin \phi_1} \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
    3. lift-sin.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \color{blue}{\sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}} \]
    4. sin-multN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}{2}}} \]
    5. clear-numN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{1}{\frac{2}{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}}}} \]
    6. lower-/.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{1}{\frac{2}{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}}}} \]
    7. clear-numN/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \frac{1}{\color{blue}{\frac{1}{\frac{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}{2}}}}} \]
  4. Applied rewrites99.7%

    \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{1}{\frac{1}{\mathsf{fma}\left(\cos theta, \sin delta \cdot \cos \phi_1, \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1}}}} \]
  5. Taylor expanded in delta around 0

    \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{{\sin \phi_1}^{2}}} \]
  6. Step-by-step derivation
    1. lower-pow.f64N/A

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{{\sin \phi_1}^{2}}} \]
    2. lower-sin.f6493.5

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - {\color{blue}{\sin \phi_1}}^{2}} \]
  7. Applied rewrites93.5%

    \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{{\sin \phi_1}^{2}}} \]
  8. Step-by-step derivation
    1. Applied rewrites93.5%

      \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \left(0.5 - \color{blue}{0.5 \cdot \cos \left(\phi_1 + \phi_1\right)}\right)} \]
    2. Final simplification93.5%

      \[\leadsto \tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\cos delta - \left(0.5 - \cos \left(\phi_1 + \phi_1\right) \cdot 0.5\right)} + \lambda_1 \]
    3. Add Preprocessing

    Alternative 10: 91.1% accurate, 2.1× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_1 := \cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)\\ \mathbf{if}\;delta \leq -3.8 \cdot 10^{+18}:\\ \;\;\;\;\tan^{-1}_* \frac{t\_1}{\cos delta - \phi_1 \cdot \phi_1} + \lambda_1\\ \mathbf{elif}\;delta \leq 0.031:\\ \;\;\;\;\tan^{-1}_* \frac{t\_1}{{\cos \phi_1}^{2}} + \lambda_1\\ \mathbf{else}:\\ \;\;\;\;\tan^{-1}_* \frac{t\_1}{\cos delta} + \lambda_1\\ \end{array} \end{array} \]
    (FPCore (lambda1 phi1 phi2 delta theta)
     :precision binary64
     (let* ((t_1 (* (cos phi1) (* (sin delta) (sin theta)))))
       (if (<= delta -3.8e+18)
         (+ (atan2 t_1 (- (cos delta) (* phi1 phi1))) lambda1)
         (if (<= delta 0.031)
           (+ (atan2 t_1 (pow (cos phi1) 2.0)) lambda1)
           (+ (atan2 t_1 (cos delta)) lambda1)))))
    double code(double lambda1, double phi1, double phi2, double delta, double theta) {
    	double t_1 = cos(phi1) * (sin(delta) * sin(theta));
    	double tmp;
    	if (delta <= -3.8e+18) {
    		tmp = atan2(t_1, (cos(delta) - (phi1 * phi1))) + lambda1;
    	} else if (delta <= 0.031) {
    		tmp = atan2(t_1, pow(cos(phi1), 2.0)) + lambda1;
    	} else {
    		tmp = atan2(t_1, cos(delta)) + lambda1;
    	}
    	return tmp;
    }
    
    real(8) function code(lambda1, phi1, phi2, delta, theta)
        real(8), intent (in) :: lambda1
        real(8), intent (in) :: phi1
        real(8), intent (in) :: phi2
        real(8), intent (in) :: delta
        real(8), intent (in) :: theta
        real(8) :: t_1
        real(8) :: tmp
        t_1 = cos(phi1) * (sin(delta) * sin(theta))
        if (delta <= (-3.8d+18)) then
            tmp = atan2(t_1, (cos(delta) - (phi1 * phi1))) + lambda1
        else if (delta <= 0.031d0) then
            tmp = atan2(t_1, (cos(phi1) ** 2.0d0)) + lambda1
        else
            tmp = atan2(t_1, cos(delta)) + lambda1
        end if
        code = tmp
    end function
    
    public static double code(double lambda1, double phi1, double phi2, double delta, double theta) {
    	double t_1 = Math.cos(phi1) * (Math.sin(delta) * Math.sin(theta));
    	double tmp;
    	if (delta <= -3.8e+18) {
    		tmp = Math.atan2(t_1, (Math.cos(delta) - (phi1 * phi1))) + lambda1;
    	} else if (delta <= 0.031) {
    		tmp = Math.atan2(t_1, Math.pow(Math.cos(phi1), 2.0)) + lambda1;
    	} else {
    		tmp = Math.atan2(t_1, Math.cos(delta)) + lambda1;
    	}
    	return tmp;
    }
    
    def code(lambda1, phi1, phi2, delta, theta):
    	t_1 = math.cos(phi1) * (math.sin(delta) * math.sin(theta))
    	tmp = 0
    	if delta <= -3.8e+18:
    		tmp = math.atan2(t_1, (math.cos(delta) - (phi1 * phi1))) + lambda1
    	elif delta <= 0.031:
    		tmp = math.atan2(t_1, math.pow(math.cos(phi1), 2.0)) + lambda1
    	else:
    		tmp = math.atan2(t_1, math.cos(delta)) + lambda1
    	return tmp
    
    function code(lambda1, phi1, phi2, delta, theta)
    	t_1 = Float64(cos(phi1) * Float64(sin(delta) * sin(theta)))
    	tmp = 0.0
    	if (delta <= -3.8e+18)
    		tmp = Float64(atan(t_1, Float64(cos(delta) - Float64(phi1 * phi1))) + lambda1);
    	elseif (delta <= 0.031)
    		tmp = Float64(atan(t_1, (cos(phi1) ^ 2.0)) + lambda1);
    	else
    		tmp = Float64(atan(t_1, cos(delta)) + lambda1);
    	end
    	return tmp
    end
    
    function tmp_2 = code(lambda1, phi1, phi2, delta, theta)
    	t_1 = cos(phi1) * (sin(delta) * sin(theta));
    	tmp = 0.0;
    	if (delta <= -3.8e+18)
    		tmp = atan2(t_1, (cos(delta) - (phi1 * phi1))) + lambda1;
    	elseif (delta <= 0.031)
    		tmp = atan2(t_1, (cos(phi1) ^ 2.0)) + lambda1;
    	else
    		tmp = atan2(t_1, cos(delta)) + lambda1;
    	end
    	tmp_2 = tmp;
    end
    
    code[lambda1_, phi1_, phi2_, delta_, theta_] := Block[{t$95$1 = N[(N[Cos[phi1], $MachinePrecision] * N[(N[Sin[delta], $MachinePrecision] * N[Sin[theta], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[delta, -3.8e+18], N[(N[ArcTan[t$95$1 / N[(N[Cos[delta], $MachinePrecision] - N[(phi1 * phi1), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + lambda1), $MachinePrecision], If[LessEqual[delta, 0.031], N[(N[ArcTan[t$95$1 / N[Power[N[Cos[phi1], $MachinePrecision], 2.0], $MachinePrecision]], $MachinePrecision] + lambda1), $MachinePrecision], N[(N[ArcTan[t$95$1 / N[Cos[delta], $MachinePrecision]], $MachinePrecision] + lambda1), $MachinePrecision]]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_1 := \cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)\\
    \mathbf{if}\;delta \leq -3.8 \cdot 10^{+18}:\\
    \;\;\;\;\tan^{-1}_* \frac{t\_1}{\cos delta - \phi_1 \cdot \phi_1} + \lambda_1\\
    
    \mathbf{elif}\;delta \leq 0.031:\\
    \;\;\;\;\tan^{-1}_* \frac{t\_1}{{\cos \phi_1}^{2}} + \lambda_1\\
    
    \mathbf{else}:\\
    \;\;\;\;\tan^{-1}_* \frac{t\_1}{\cos delta} + \lambda_1\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if delta < -3.8e18

      1. Initial program 99.8%

        \[\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift-*.f64N/A

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}} \]
        2. lift-sin.f64N/A

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\sin \phi_1} \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
        3. lift-sin.f64N/A

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \color{blue}{\sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}} \]
        4. sin-multN/A

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}{2}}} \]
        5. clear-numN/A

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{1}{\frac{2}{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}}}} \]
        6. lower-/.f64N/A

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{1}{\frac{2}{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}}}} \]
        7. clear-numN/A

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \frac{1}{\color{blue}{\frac{1}{\frac{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}{2}}}}} \]
      4. Applied rewrites99.8%

        \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{1}{\frac{1}{\mathsf{fma}\left(\cos theta, \sin delta \cdot \cos \phi_1, \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1}}}} \]
      5. Taylor expanded in delta around 0

        \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{{\sin \phi_1}^{2}}} \]
      6. Step-by-step derivation
        1. lower-pow.f64N/A

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{{\sin \phi_1}^{2}}} \]
        2. lower-sin.f6489.1

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - {\color{blue}{\sin \phi_1}}^{2}} \]
      7. Applied rewrites89.1%

        \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{{\sin \phi_1}^{2}}} \]
      8. Taylor expanded in phi1 around 0

        \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - {\phi_1}^{\color{blue}{2}}} \]
      9. Step-by-step derivation
        1. Applied rewrites88.7%

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \phi_1 \cdot \color{blue}{\phi_1}} \]

        if -3.8e18 < delta < 0.031

        1. Initial program 99.8%

          \[\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
        2. Add Preprocessing
        3. Step-by-step derivation
          1. lift-*.f64N/A

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}} \]
          2. lift-sin.f64N/A

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\sin \phi_1} \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
          3. lift-sin.f64N/A

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \color{blue}{\sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)}} \]
          4. sin-multN/A

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}{2}}} \]
          5. clear-numN/A

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{1}{\frac{2}{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}}}} \]
          6. lower-/.f64N/A

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{1}{\frac{2}{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}}}} \]
          7. clear-numN/A

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \frac{1}{\color{blue}{\frac{1}{\frac{\cos \left(\phi_1 - \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right) - \cos \left(\phi_1 + \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}{2}}}}} \]
        4. Applied rewrites99.8%

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \color{blue}{\frac{1}{\frac{1}{\mathsf{fma}\left(\cos theta, \sin delta \cdot \cos \phi_1, \cos delta \cdot \sin \phi_1\right) \cdot \sin \phi_1}}}} \]
        5. Taylor expanded in delta around 0

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{1 - {\sin \phi_1}^{2}}} \]
        6. Step-by-step derivation
          1. unpow2N/A

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{1 - \color{blue}{\sin \phi_1 \cdot \sin \phi_1}} \]
          2. 1-sub-sinN/A

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos \phi_1 \cdot \cos \phi_1}} \]
          3. unpow2N/A

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{{\cos \phi_1}^{2}}} \]
          4. lower-pow.f64N/A

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{{\cos \phi_1}^{2}}} \]
          5. lower-cos.f6499.1

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{{\color{blue}{\cos \phi_1}}^{2}} \]
        7. Applied rewrites99.1%

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{{\cos \phi_1}^{2}}} \]

        if 0.031 < delta

        1. Initial program 99.5%

          \[\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
        2. Add Preprocessing
        3. Taylor expanded in phi1 around 0

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta}} \]
        4. Step-by-step derivation
          1. lower-cos.f6485.1

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta}} \]
        5. Applied rewrites85.1%

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta}} \]
      10. Recombined 3 regimes into one program.
      11. Final simplification93.8%

        \[\leadsto \begin{array}{l} \mathbf{if}\;delta \leq -3.8 \cdot 10^{+18}:\\ \;\;\;\;\tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\cos delta - \phi_1 \cdot \phi_1} + \lambda_1\\ \mathbf{elif}\;delta \leq 0.031:\\ \;\;\;\;\tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{{\cos \phi_1}^{2}} + \lambda_1\\ \mathbf{else}:\\ \;\;\;\;\tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\cos delta} + \lambda_1\\ \end{array} \]
      12. Add Preprocessing

      Alternative 11: 88.7% accurate, 2.6× speedup?

      \[\begin{array}{l} \\ \tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\cos delta} + \lambda_1 \end{array} \]
      (FPCore (lambda1 phi1 phi2 delta theta)
       :precision binary64
       (+ (atan2 (* (cos phi1) (* (sin delta) (sin theta))) (cos delta)) lambda1))
      double code(double lambda1, double phi1, double phi2, double delta, double theta) {
      	return atan2((cos(phi1) * (sin(delta) * sin(theta))), cos(delta)) + lambda1;
      }
      
      real(8) function code(lambda1, phi1, phi2, delta, theta)
          real(8), intent (in) :: lambda1
          real(8), intent (in) :: phi1
          real(8), intent (in) :: phi2
          real(8), intent (in) :: delta
          real(8), intent (in) :: theta
          code = atan2((cos(phi1) * (sin(delta) * sin(theta))), cos(delta)) + lambda1
      end function
      
      public static double code(double lambda1, double phi1, double phi2, double delta, double theta) {
      	return Math.atan2((Math.cos(phi1) * (Math.sin(delta) * Math.sin(theta))), Math.cos(delta)) + lambda1;
      }
      
      def code(lambda1, phi1, phi2, delta, theta):
      	return math.atan2((math.cos(phi1) * (math.sin(delta) * math.sin(theta))), math.cos(delta)) + lambda1
      
      function code(lambda1, phi1, phi2, delta, theta)
      	return Float64(atan(Float64(cos(phi1) * Float64(sin(delta) * sin(theta))), cos(delta)) + lambda1)
      end
      
      function tmp = code(lambda1, phi1, phi2, delta, theta)
      	tmp = atan2((cos(phi1) * (sin(delta) * sin(theta))), cos(delta)) + lambda1;
      end
      
      code[lambda1_, phi1_, phi2_, delta_, theta_] := N[(N[ArcTan[N[(N[Cos[phi1], $MachinePrecision] * N[(N[Sin[delta], $MachinePrecision] * N[Sin[theta], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Cos[delta], $MachinePrecision]], $MachinePrecision] + lambda1), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\cos delta} + \lambda_1
      \end{array}
      
      Derivation
      1. Initial program 99.7%

        \[\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
      2. Add Preprocessing
      3. Taylor expanded in phi1 around 0

        \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta}} \]
      4. Step-by-step derivation
        1. lower-cos.f6490.5

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta}} \]
      5. Applied rewrites90.5%

        \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta}} \]
      6. Final simplification90.5%

        \[\leadsto \tan^{-1}_* \frac{\cos \phi_1 \cdot \left(\sin delta \cdot \sin theta\right)}{\cos delta} + \lambda_1 \]
      7. Add Preprocessing

      Alternative 12: 86.2% accurate, 3.3× speedup?

      \[\begin{array}{l} \\ \tan^{-1}_* \frac{\sin delta \cdot \sin theta}{\cos delta} + \lambda_1 \end{array} \]
      (FPCore (lambda1 phi1 phi2 delta theta)
       :precision binary64
       (+ (atan2 (* (sin delta) (sin theta)) (cos delta)) lambda1))
      double code(double lambda1, double phi1, double phi2, double delta, double theta) {
      	return atan2((sin(delta) * sin(theta)), cos(delta)) + lambda1;
      }
      
      real(8) function code(lambda1, phi1, phi2, delta, theta)
          real(8), intent (in) :: lambda1
          real(8), intent (in) :: phi1
          real(8), intent (in) :: phi2
          real(8), intent (in) :: delta
          real(8), intent (in) :: theta
          code = atan2((sin(delta) * sin(theta)), cos(delta)) + lambda1
      end function
      
      public static double code(double lambda1, double phi1, double phi2, double delta, double theta) {
      	return Math.atan2((Math.sin(delta) * Math.sin(theta)), Math.cos(delta)) + lambda1;
      }
      
      def code(lambda1, phi1, phi2, delta, theta):
      	return math.atan2((math.sin(delta) * math.sin(theta)), math.cos(delta)) + lambda1
      
      function code(lambda1, phi1, phi2, delta, theta)
      	return Float64(atan(Float64(sin(delta) * sin(theta)), cos(delta)) + lambda1)
      end
      
      function tmp = code(lambda1, phi1, phi2, delta, theta)
      	tmp = atan2((sin(delta) * sin(theta)), cos(delta)) + lambda1;
      end
      
      code[lambda1_, phi1_, phi2_, delta_, theta_] := N[(N[ArcTan[N[(N[Sin[delta], $MachinePrecision] * N[Sin[theta], $MachinePrecision]), $MachinePrecision] / N[Cos[delta], $MachinePrecision]], $MachinePrecision] + lambda1), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \tan^{-1}_* \frac{\sin delta \cdot \sin theta}{\cos delta} + \lambda_1
      \end{array}
      
      Derivation
      1. Initial program 99.7%

        \[\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
      2. Add Preprocessing
      3. Taylor expanded in phi1 around 0

        \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta}} \]
      4. Step-by-step derivation
        1. lower-cos.f6490.5

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta}} \]
      5. Applied rewrites90.5%

        \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta}} \]
      6. Taylor expanded in phi1 around 0

        \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin delta \cdot \sin theta}}{\cos delta} \]
      7. Step-by-step derivation
        1. *-commutativeN/A

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin theta \cdot \sin delta}}{\cos delta} \]
        2. lower-*.f64N/A

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin theta \cdot \sin delta}}{\cos delta} \]
        3. lower-sin.f64N/A

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin theta} \cdot \sin delta}{\cos delta} \]
        4. lower-sin.f6488.6

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\sin theta \cdot \color{blue}{\sin delta}}{\cos delta} \]
      8. Applied rewrites88.6%

        \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin theta \cdot \sin delta}}{\cos delta} \]
      9. Final simplification88.6%

        \[\leadsto \tan^{-1}_* \frac{\sin delta \cdot \sin theta}{\cos delta} + \lambda_1 \]
      10. Add Preprocessing

      Alternative 13: 79.5% accurate, 4.2× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} t_1 := \tan^{-1}_* \frac{\sin delta \cdot theta}{\cos delta} + \lambda_1\\ \mathbf{if}\;delta \leq -2.55 \cdot 10^{+14}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;delta \leq 2.9 \cdot 10^{+110}:\\ \;\;\;\;\tan^{-1}_* \frac{delta \cdot \sin theta}{\cos delta} + \lambda_1\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
      (FPCore (lambda1 phi1 phi2 delta theta)
       :precision binary64
       (let* ((t_1 (+ (atan2 (* (sin delta) theta) (cos delta)) lambda1)))
         (if (<= delta -2.55e+14)
           t_1
           (if (<= delta 2.9e+110)
             (+ (atan2 (* delta (sin theta)) (cos delta)) lambda1)
             t_1))))
      double code(double lambda1, double phi1, double phi2, double delta, double theta) {
      	double t_1 = atan2((sin(delta) * theta), cos(delta)) + lambda1;
      	double tmp;
      	if (delta <= -2.55e+14) {
      		tmp = t_1;
      	} else if (delta <= 2.9e+110) {
      		tmp = atan2((delta * sin(theta)), cos(delta)) + lambda1;
      	} else {
      		tmp = t_1;
      	}
      	return tmp;
      }
      
      real(8) function code(lambda1, phi1, phi2, delta, theta)
          real(8), intent (in) :: lambda1
          real(8), intent (in) :: phi1
          real(8), intent (in) :: phi2
          real(8), intent (in) :: delta
          real(8), intent (in) :: theta
          real(8) :: t_1
          real(8) :: tmp
          t_1 = atan2((sin(delta) * theta), cos(delta)) + lambda1
          if (delta <= (-2.55d+14)) then
              tmp = t_1
          else if (delta <= 2.9d+110) then
              tmp = atan2((delta * sin(theta)), cos(delta)) + lambda1
          else
              tmp = t_1
          end if
          code = tmp
      end function
      
      public static double code(double lambda1, double phi1, double phi2, double delta, double theta) {
      	double t_1 = Math.atan2((Math.sin(delta) * theta), Math.cos(delta)) + lambda1;
      	double tmp;
      	if (delta <= -2.55e+14) {
      		tmp = t_1;
      	} else if (delta <= 2.9e+110) {
      		tmp = Math.atan2((delta * Math.sin(theta)), Math.cos(delta)) + lambda1;
      	} else {
      		tmp = t_1;
      	}
      	return tmp;
      }
      
      def code(lambda1, phi1, phi2, delta, theta):
      	t_1 = math.atan2((math.sin(delta) * theta), math.cos(delta)) + lambda1
      	tmp = 0
      	if delta <= -2.55e+14:
      		tmp = t_1
      	elif delta <= 2.9e+110:
      		tmp = math.atan2((delta * math.sin(theta)), math.cos(delta)) + lambda1
      	else:
      		tmp = t_1
      	return tmp
      
      function code(lambda1, phi1, phi2, delta, theta)
      	t_1 = Float64(atan(Float64(sin(delta) * theta), cos(delta)) + lambda1)
      	tmp = 0.0
      	if (delta <= -2.55e+14)
      		tmp = t_1;
      	elseif (delta <= 2.9e+110)
      		tmp = Float64(atan(Float64(delta * sin(theta)), cos(delta)) + lambda1);
      	else
      		tmp = t_1;
      	end
      	return tmp
      end
      
      function tmp_2 = code(lambda1, phi1, phi2, delta, theta)
      	t_1 = atan2((sin(delta) * theta), cos(delta)) + lambda1;
      	tmp = 0.0;
      	if (delta <= -2.55e+14)
      		tmp = t_1;
      	elseif (delta <= 2.9e+110)
      		tmp = atan2((delta * sin(theta)), cos(delta)) + lambda1;
      	else
      		tmp = t_1;
      	end
      	tmp_2 = tmp;
      end
      
      code[lambda1_, phi1_, phi2_, delta_, theta_] := Block[{t$95$1 = N[(N[ArcTan[N[(N[Sin[delta], $MachinePrecision] * theta), $MachinePrecision] / N[Cos[delta], $MachinePrecision]], $MachinePrecision] + lambda1), $MachinePrecision]}, If[LessEqual[delta, -2.55e+14], t$95$1, If[LessEqual[delta, 2.9e+110], N[(N[ArcTan[N[(delta * N[Sin[theta], $MachinePrecision]), $MachinePrecision] / N[Cos[delta], $MachinePrecision]], $MachinePrecision] + lambda1), $MachinePrecision], t$95$1]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      t_1 := \tan^{-1}_* \frac{\sin delta \cdot theta}{\cos delta} + \lambda_1\\
      \mathbf{if}\;delta \leq -2.55 \cdot 10^{+14}:\\
      \;\;\;\;t\_1\\
      
      \mathbf{elif}\;delta \leq 2.9 \cdot 10^{+110}:\\
      \;\;\;\;\tan^{-1}_* \frac{delta \cdot \sin theta}{\cos delta} + \lambda_1\\
      
      \mathbf{else}:\\
      \;\;\;\;t\_1\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if delta < -2.55e14 or 2.9e110 < delta

        1. Initial program 99.8%

          \[\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
        2. Add Preprocessing
        3. Taylor expanded in phi1 around 0

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta}} \]
        4. Step-by-step derivation
          1. lower-cos.f6487.5

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta}} \]
        5. Applied rewrites87.5%

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta}} \]
        6. Taylor expanded in phi1 around 0

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin delta \cdot \sin theta}}{\cos delta} \]
        7. Step-by-step derivation
          1. *-commutativeN/A

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin theta \cdot \sin delta}}{\cos delta} \]
          2. lower-*.f64N/A

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin theta \cdot \sin delta}}{\cos delta} \]
          3. lower-sin.f64N/A

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin theta} \cdot \sin delta}{\cos delta} \]
          4. lower-sin.f6484.7

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\sin theta \cdot \color{blue}{\sin delta}}{\cos delta} \]
        8. Applied rewrites84.7%

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin theta \cdot \sin delta}}{\cos delta} \]
        9. Taylor expanded in theta around 0

          \[\leadsto \lambda_1 + \tan^{-1}_* \frac{theta \cdot \color{blue}{\sin delta}}{\cos delta} \]
        10. Step-by-step derivation
          1. Applied rewrites70.4%

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{theta \cdot \color{blue}{\sin delta}}{\cos delta} \]

          if -2.55e14 < delta < 2.9e110

          1. Initial program 99.7%

            \[\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
          2. Add Preprocessing
          3. Taylor expanded in phi1 around 0

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta}} \]
          4. Step-by-step derivation
            1. lower-cos.f6492.4

              \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta}} \]
          5. Applied rewrites92.4%

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta}} \]
          6. Taylor expanded in phi1 around 0

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin delta \cdot \sin theta}}{\cos delta} \]
          7. Step-by-step derivation
            1. *-commutativeN/A

              \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin theta \cdot \sin delta}}{\cos delta} \]
            2. lower-*.f64N/A

              \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin theta \cdot \sin delta}}{\cos delta} \]
            3. lower-sin.f64N/A

              \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin theta} \cdot \sin delta}{\cos delta} \]
            4. lower-sin.f6491.0

              \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\sin theta \cdot \color{blue}{\sin delta}}{\cos delta} \]
          8. Applied rewrites91.0%

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin theta \cdot \sin delta}}{\cos delta} \]
          9. Taylor expanded in delta around 0

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{delta \cdot \color{blue}{\sin theta}}{\cos delta} \]
          10. Step-by-step derivation
            1. Applied rewrites88.4%

              \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\sin theta \cdot \color{blue}{delta}}{\cos delta} \]
          11. Recombined 2 regimes into one program.
          12. Final simplification81.5%

            \[\leadsto \begin{array}{l} \mathbf{if}\;delta \leq -2.55 \cdot 10^{+14}:\\ \;\;\;\;\tan^{-1}_* \frac{\sin delta \cdot theta}{\cos delta} + \lambda_1\\ \mathbf{elif}\;delta \leq 2.9 \cdot 10^{+110}:\\ \;\;\;\;\tan^{-1}_* \frac{delta \cdot \sin theta}{\cos delta} + \lambda_1\\ \mathbf{else}:\\ \;\;\;\;\tan^{-1}_* \frac{\sin delta \cdot theta}{\cos delta} + \lambda_1\\ \end{array} \]
          13. Add Preprocessing

          Alternative 14: 72.8% accurate, 4.3× speedup?

          \[\begin{array}{l} \\ \tan^{-1}_* \frac{\sin delta \cdot theta}{\cos delta} + \lambda_1 \end{array} \]
          (FPCore (lambda1 phi1 phi2 delta theta)
           :precision binary64
           (+ (atan2 (* (sin delta) theta) (cos delta)) lambda1))
          double code(double lambda1, double phi1, double phi2, double delta, double theta) {
          	return atan2((sin(delta) * theta), cos(delta)) + lambda1;
          }
          
          real(8) function code(lambda1, phi1, phi2, delta, theta)
              real(8), intent (in) :: lambda1
              real(8), intent (in) :: phi1
              real(8), intent (in) :: phi2
              real(8), intent (in) :: delta
              real(8), intent (in) :: theta
              code = atan2((sin(delta) * theta), cos(delta)) + lambda1
          end function
          
          public static double code(double lambda1, double phi1, double phi2, double delta, double theta) {
          	return Math.atan2((Math.sin(delta) * theta), Math.cos(delta)) + lambda1;
          }
          
          def code(lambda1, phi1, phi2, delta, theta):
          	return math.atan2((math.sin(delta) * theta), math.cos(delta)) + lambda1
          
          function code(lambda1, phi1, phi2, delta, theta)
          	return Float64(atan(Float64(sin(delta) * theta), cos(delta)) + lambda1)
          end
          
          function tmp = code(lambda1, phi1, phi2, delta, theta)
          	tmp = atan2((sin(delta) * theta), cos(delta)) + lambda1;
          end
          
          code[lambda1_, phi1_, phi2_, delta_, theta_] := N[(N[ArcTan[N[(N[Sin[delta], $MachinePrecision] * theta), $MachinePrecision] / N[Cos[delta], $MachinePrecision]], $MachinePrecision] + lambda1), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \tan^{-1}_* \frac{\sin delta \cdot theta}{\cos delta} + \lambda_1
          \end{array}
          
          Derivation
          1. Initial program 99.7%

            \[\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)} \]
          2. Add Preprocessing
          3. Taylor expanded in phi1 around 0

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta}} \]
          4. Step-by-step derivation
            1. lower-cos.f6490.5

              \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta}} \]
          5. Applied rewrites90.5%

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\color{blue}{\cos delta}} \]
          6. Taylor expanded in phi1 around 0

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin delta \cdot \sin theta}}{\cos delta} \]
          7. Step-by-step derivation
            1. *-commutativeN/A

              \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin theta \cdot \sin delta}}{\cos delta} \]
            2. lower-*.f64N/A

              \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin theta \cdot \sin delta}}{\cos delta} \]
            3. lower-sin.f64N/A

              \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin theta} \cdot \sin delta}{\cos delta} \]
            4. lower-sin.f6488.6

              \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\sin theta \cdot \color{blue}{\sin delta}}{\cos delta} \]
          8. Applied rewrites88.6%

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{\color{blue}{\sin theta \cdot \sin delta}}{\cos delta} \]
          9. Taylor expanded in theta around 0

            \[\leadsto \lambda_1 + \tan^{-1}_* \frac{theta \cdot \color{blue}{\sin delta}}{\cos delta} \]
          10. Step-by-step derivation
            1. Applied rewrites71.9%

              \[\leadsto \lambda_1 + \tan^{-1}_* \frac{theta \cdot \color{blue}{\sin delta}}{\cos delta} \]
            2. Final simplification71.9%

              \[\leadsto \tan^{-1}_* \frac{\sin delta \cdot theta}{\cos delta} + \lambda_1 \]
            3. Add Preprocessing

            Reproduce

            ?
            herbie shell --seed 2024278 
            (FPCore (lambda1 phi1 phi2 delta theta)
              :name "Destination given bearing on a great circle"
              :precision binary64
              (+ lambda1 (atan2 (* (* (sin theta) (sin delta)) (cos phi1)) (- (cos delta) (* (sin phi1) (sin (asin (+ (* (sin phi1) (cos delta)) (* (* (cos phi1) (sin delta)) (cos theta))))))))))