2-ancestry mixing, negative discriminant

Percentage Accurate: 98.5% → 100.0%
Time: 3.3s
Alternatives: 3
Speedup: 1.1×

Specification

?
\[\begin{array}{l} \\ 2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \end{array} \]
(FPCore (g h)
 :precision binary64
 (* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))
double code(double g, double h) {
	return 2.0 * cos((((2.0 * ((double) M_PI)) / 3.0) + (acos((-g / h)) / 3.0)));
}
public static double code(double g, double h) {
	return 2.0 * Math.cos((((2.0 * Math.PI) / 3.0) + (Math.acos((-g / h)) / 3.0)));
}
def code(g, h):
	return 2.0 * math.cos((((2.0 * math.pi) / 3.0) + (math.acos((-g / h)) / 3.0)))
function code(g, h)
	return Float64(2.0 * cos(Float64(Float64(Float64(2.0 * pi) / 3.0) + Float64(acos(Float64(Float64(-g) / h)) / 3.0))))
end
function tmp = code(g, h)
	tmp = 2.0 * cos((((2.0 * pi) / 3.0) + (acos((-g / h)) / 3.0)));
end
code[g_, h_] := N[(2.0 * N[Cos[N[(N[(N[(2.0 * Pi), $MachinePrecision] / 3.0), $MachinePrecision] + N[(N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision] / 3.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\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 3 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: 98.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ 2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \end{array} \]
(FPCore (g h)
 :precision binary64
 (* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))
double code(double g, double h) {
	return 2.0 * cos((((2.0 * ((double) M_PI)) / 3.0) + (acos((-g / h)) / 3.0)));
}
public static double code(double g, double h) {
	return 2.0 * Math.cos((((2.0 * Math.PI) / 3.0) + (Math.acos((-g / h)) / 3.0)));
}
def code(g, h):
	return 2.0 * math.cos((((2.0 * math.pi) / 3.0) + (math.acos((-g / h)) / 3.0)))
function code(g, h)
	return Float64(2.0 * cos(Float64(Float64(Float64(2.0 * pi) / 3.0) + Float64(acos(Float64(Float64(-g) / h)) / 3.0))))
end
function tmp = code(g, h)
	tmp = 2.0 * cos((((2.0 * pi) / 3.0) + (acos((-g / h)) / 3.0)));
end
code[g_, h_] := N[(2.0 * N[Cos[N[(N[(N[(2.0 * Pi), $MachinePrecision] / 3.0), $MachinePrecision] + N[(N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision] / 3.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)
\end{array}

Alternative 1: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ 2 \cdot \sin \left(\frac{\left(\left(\pi + \cos^{-1} \left(\frac{-g}{h}\right)\right) + \pi\right) \cdot 2 - 3 \cdot \pi}{-6}\right) \end{array} \]
(FPCore (g h)
 :precision binary64
 (*
  2.0
  (sin (/ (- (* (+ (+ PI (acos (/ (- g) h))) PI) 2.0) (* 3.0 PI)) -6.0))))
double code(double g, double h) {
	return 2.0 * sin((((((((double) M_PI) + acos((-g / h))) + ((double) M_PI)) * 2.0) - (3.0 * ((double) M_PI))) / -6.0));
}
public static double code(double g, double h) {
	return 2.0 * Math.sin((((((Math.PI + Math.acos((-g / h))) + Math.PI) * 2.0) - (3.0 * Math.PI)) / -6.0));
}
def code(g, h):
	return 2.0 * math.sin((((((math.pi + math.acos((-g / h))) + math.pi) * 2.0) - (3.0 * math.pi)) / -6.0))
function code(g, h)
	return Float64(2.0 * sin(Float64(Float64(Float64(Float64(Float64(pi + acos(Float64(Float64(-g) / h))) + pi) * 2.0) - Float64(3.0 * pi)) / -6.0)))
end
function tmp = code(g, h)
	tmp = 2.0 * sin((((((pi + acos((-g / h))) + pi) * 2.0) - (3.0 * pi)) / -6.0));
end
code[g_, h_] := N[(2.0 * N[Sin[N[(N[(N[(N[(N[(Pi + N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] + Pi), $MachinePrecision] * 2.0), $MachinePrecision] - N[(3.0 * Pi), $MachinePrecision]), $MachinePrecision] / -6.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
2 \cdot \sin \left(\frac{\left(\left(\pi + \cos^{-1} \left(\frac{-g}{h}\right)\right) + \pi\right) \cdot 2 - 3 \cdot \pi}{-6}\right)
\end{array}
Derivation
  1. Initial program 98.5%

    \[2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-cos.f64N/A

      \[\leadsto 2 \cdot \color{blue}{\cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)} \]
    2. cos-neg-revN/A

      \[\leadsto 2 \cdot \color{blue}{\cos \left(\mathsf{neg}\left(\left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)\right)\right)} \]
    3. sin-+PI/2-revN/A

      \[\leadsto 2 \cdot \color{blue}{\sin \left(\left(\mathsf{neg}\left(\left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)\right)\right) + \frac{\mathsf{PI}\left(\right)}{2}\right)} \]
    4. lower-sin.f64N/A

      \[\leadsto 2 \cdot \color{blue}{\sin \left(\left(\mathsf{neg}\left(\left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)\right)\right) + \frac{\mathsf{PI}\left(\right)}{2}\right)} \]
    5. lower-+.f64N/A

      \[\leadsto 2 \cdot \sin \color{blue}{\left(\left(\mathsf{neg}\left(\left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)\right)\right) + \frac{\mathsf{PI}\left(\right)}{2}\right)} \]
  4. Applied rewrites98.5%

    \[\leadsto 2 \cdot \color{blue}{\sin \left(\frac{\cos^{-1} \left(\frac{-g}{h}\right) + \pi \cdot 2}{-3} + \frac{\pi}{2}\right)} \]
  5. Step-by-step derivation
    1. lift-+.f64N/A

      \[\leadsto 2 \cdot \sin \color{blue}{\left(\frac{\cos^{-1} \left(\frac{-g}{h}\right) + \pi \cdot 2}{-3} + \frac{\pi}{2}\right)} \]
    2. lift-/.f64N/A

      \[\leadsto 2 \cdot \sin \left(\color{blue}{\frac{\cos^{-1} \left(\frac{-g}{h}\right) + \pi \cdot 2}{-3}} + \frac{\pi}{2}\right) \]
    3. lift-PI.f64N/A

      \[\leadsto 2 \cdot \sin \left(\frac{\cos^{-1} \left(\frac{-g}{h}\right) + \pi \cdot 2}{-3} + \frac{\color{blue}{\mathsf{PI}\left(\right)}}{2}\right) \]
    4. lift-/.f64N/A

      \[\leadsto 2 \cdot \sin \left(\frac{\cos^{-1} \left(\frac{-g}{h}\right) + \pi \cdot 2}{-3} + \color{blue}{\frac{\mathsf{PI}\left(\right)}{2}}\right) \]
    5. frac-addN/A

      \[\leadsto 2 \cdot \sin \color{blue}{\left(\frac{\left(\cos^{-1} \left(\frac{-g}{h}\right) + \pi \cdot 2\right) \cdot 2 + -3 \cdot \mathsf{PI}\left(\right)}{-3 \cdot 2}\right)} \]
    6. lower-/.f64N/A

      \[\leadsto 2 \cdot \sin \color{blue}{\left(\frac{\left(\cos^{-1} \left(\frac{-g}{h}\right) + \pi \cdot 2\right) \cdot 2 + -3 \cdot \mathsf{PI}\left(\right)}{-3 \cdot 2}\right)} \]
  6. Applied rewrites100.0%

    \[\leadsto 2 \cdot \sin \color{blue}{\left(\frac{\left(\cos^{-1} \left(\frac{-g}{h}\right) - -2 \cdot \pi\right) \cdot 2 - 3 \cdot \pi}{-6}\right)} \]
  7. Step-by-step derivation
    1. lift--.f64N/A

      \[\leadsto 2 \cdot \sin \left(\frac{\color{blue}{\left(\cos^{-1} \left(\frac{-g}{h}\right) - -2 \cdot \pi\right)} \cdot 2 - 3 \cdot \pi}{-6}\right) \]
    2. lift-PI.f64N/A

      \[\leadsto 2 \cdot \sin \left(\frac{\left(\cos^{-1} \left(\frac{-g}{h}\right) - -2 \cdot \color{blue}{\mathsf{PI}\left(\right)}\right) \cdot 2 - 3 \cdot \pi}{-6}\right) \]
    3. lift-*.f64N/A

      \[\leadsto 2 \cdot \sin \left(\frac{\left(\cos^{-1} \left(\frac{-g}{h}\right) - \color{blue}{-2 \cdot \mathsf{PI}\left(\right)}\right) \cdot 2 - 3 \cdot \pi}{-6}\right) \]
    4. fp-cancel-sub-sign-invN/A

      \[\leadsto 2 \cdot \sin \left(\frac{\color{blue}{\left(\cos^{-1} \left(\frac{-g}{h}\right) + \left(\mathsf{neg}\left(-2\right)\right) \cdot \mathsf{PI}\left(\right)\right)} \cdot 2 - 3 \cdot \pi}{-6}\right) \]
    5. metadata-evalN/A

      \[\leadsto 2 \cdot \sin \left(\frac{\left(\cos^{-1} \left(\frac{-g}{h}\right) + \color{blue}{2} \cdot \mathsf{PI}\left(\right)\right) \cdot 2 - 3 \cdot \pi}{-6}\right) \]
    6. count-2-revN/A

      \[\leadsto 2 \cdot \sin \left(\frac{\left(\cos^{-1} \left(\frac{-g}{h}\right) + \color{blue}{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right)}\right) \cdot 2 - 3 \cdot \pi}{-6}\right) \]
    7. associate-+l+N/A

      \[\leadsto 2 \cdot \sin \left(\frac{\color{blue}{\left(\left(\cos^{-1} \left(\frac{-g}{h}\right) + \mathsf{PI}\left(\right)\right) + \mathsf{PI}\left(\right)\right)} \cdot 2 - 3 \cdot \pi}{-6}\right) \]
    8. lift-+.f64N/A

      \[\leadsto 2 \cdot \sin \left(\frac{\left(\color{blue}{\left(\cos^{-1} \left(\frac{-g}{h}\right) + \mathsf{PI}\left(\right)\right)} + \mathsf{PI}\left(\right)\right) \cdot 2 - 3 \cdot \pi}{-6}\right) \]
    9. lift-PI.f64N/A

      \[\leadsto 2 \cdot \sin \left(\frac{\left(\left(\cos^{-1} \left(\frac{-g}{h}\right) + \color{blue}{\pi}\right) + \mathsf{PI}\left(\right)\right) \cdot 2 - 3 \cdot \pi}{-6}\right) \]
    10. lift-+.f64N/A

      \[\leadsto 2 \cdot \sin \left(\frac{\color{blue}{\left(\left(\cos^{-1} \left(\frac{-g}{h}\right) + \pi\right) + \mathsf{PI}\left(\right)\right)} \cdot 2 - 3 \cdot \pi}{-6}\right) \]
    11. lift-PI.f64100.0

      \[\leadsto 2 \cdot \sin \left(\frac{\left(\left(\cos^{-1} \left(\frac{-g}{h}\right) + \pi\right) + \color{blue}{\pi}\right) \cdot 2 - 3 \cdot \pi}{-6}\right) \]
    12. lift-PI.f64N/A

      \[\leadsto 2 \cdot \sin \left(\frac{\left(\left(\cos^{-1} \left(\frac{-g}{h}\right) + \color{blue}{\mathsf{PI}\left(\right)}\right) + \pi\right) \cdot 2 - 3 \cdot \pi}{-6}\right) \]
    13. lift-+.f64N/A

      \[\leadsto 2 \cdot \sin \left(\frac{\left(\color{blue}{\left(\cos^{-1} \left(\frac{-g}{h}\right) + \mathsf{PI}\left(\right)\right)} + \pi\right) \cdot 2 - 3 \cdot \pi}{-6}\right) \]
    14. +-commutativeN/A

      \[\leadsto 2 \cdot \sin \left(\frac{\left(\color{blue}{\left(\mathsf{PI}\left(\right) + \cos^{-1} \left(\frac{-g}{h}\right)\right)} + \pi\right) \cdot 2 - 3 \cdot \pi}{-6}\right) \]
    15. lower-+.f64N/A

      \[\leadsto 2 \cdot \sin \left(\frac{\left(\color{blue}{\left(\mathsf{PI}\left(\right) + \cos^{-1} \left(\frac{-g}{h}\right)\right)} + \pi\right) \cdot 2 - 3 \cdot \pi}{-6}\right) \]
    16. lift-PI.f64100.0

      \[\leadsto 2 \cdot \sin \left(\frac{\left(\left(\color{blue}{\pi} + \cos^{-1} \left(\frac{-g}{h}\right)\right) + \pi\right) \cdot 2 - 3 \cdot \pi}{-6}\right) \]
  8. Applied rewrites100.0%

    \[\leadsto 2 \cdot \sin \left(\frac{\color{blue}{\left(\left(\pi + \cos^{-1} \left(\frac{-g}{h}\right)\right) + \pi\right)} \cdot 2 - 3 \cdot \pi}{-6}\right) \]
  9. Add Preprocessing

Alternative 2: 100.0% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \sin \left(\pi \cdot -0.16666666666666666 - 0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot 2 \end{array} \]
(FPCore (g h)
 :precision binary64
 (*
  (sin
   (- (* PI -0.16666666666666666) (* 0.3333333333333333 (acos (/ (- g) h)))))
  2.0))
double code(double g, double h) {
	return sin(((((double) M_PI) * -0.16666666666666666) - (0.3333333333333333 * acos((-g / h))))) * 2.0;
}
public static double code(double g, double h) {
	return Math.sin(((Math.PI * -0.16666666666666666) - (0.3333333333333333 * Math.acos((-g / h))))) * 2.0;
}
def code(g, h):
	return math.sin(((math.pi * -0.16666666666666666) - (0.3333333333333333 * math.acos((-g / h))))) * 2.0
function code(g, h)
	return Float64(sin(Float64(Float64(pi * -0.16666666666666666) - Float64(0.3333333333333333 * acos(Float64(Float64(-g) / h))))) * 2.0)
end
function tmp = code(g, h)
	tmp = sin(((pi * -0.16666666666666666) - (0.3333333333333333 * acos((-g / h))))) * 2.0;
end
code[g_, h_] := N[(N[Sin[N[(N[(Pi * -0.16666666666666666), $MachinePrecision] - N[(0.3333333333333333 * N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]
\begin{array}{l}

\\
\sin \left(\pi \cdot -0.16666666666666666 - 0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot 2
\end{array}
Derivation
  1. Initial program 98.5%

    \[2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-cos.f64N/A

      \[\leadsto 2 \cdot \color{blue}{\cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)} \]
    2. cos-neg-revN/A

      \[\leadsto 2 \cdot \color{blue}{\cos \left(\mathsf{neg}\left(\left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)\right)\right)} \]
    3. sin-+PI/2-revN/A

      \[\leadsto 2 \cdot \color{blue}{\sin \left(\left(\mathsf{neg}\left(\left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)\right)\right) + \frac{\mathsf{PI}\left(\right)}{2}\right)} \]
    4. lower-sin.f64N/A

      \[\leadsto 2 \cdot \color{blue}{\sin \left(\left(\mathsf{neg}\left(\left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)\right)\right) + \frac{\mathsf{PI}\left(\right)}{2}\right)} \]
    5. lower-+.f64N/A

      \[\leadsto 2 \cdot \sin \color{blue}{\left(\left(\mathsf{neg}\left(\left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)\right)\right) + \frac{\mathsf{PI}\left(\right)}{2}\right)} \]
  4. Applied rewrites98.5%

    \[\leadsto 2 \cdot \color{blue}{\sin \left(\frac{\cos^{-1} \left(\frac{-g}{h}\right) + \pi \cdot 2}{-3} + \frac{\pi}{2}\right)} \]
  5. Taylor expanded in g around 0

    \[\leadsto 2 \cdot \sin \color{blue}{\left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(-1 \cdot \frac{g}{h}\right) + 2 \cdot \mathsf{PI}\left(\right)\right) + \frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)} \]
  6. Step-by-step derivation
    1. fp-cancel-sign-sub-invN/A

      \[\leadsto 2 \cdot \sin \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(-1 \cdot \frac{g}{h}\right) + 2 \cdot \mathsf{PI}\left(\right)\right) - \color{blue}{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot \mathsf{PI}\left(\right)}\right) \]
    2. distribute-rgt-inN/A

      \[\leadsto 2 \cdot \sin \left(\left(\cos^{-1} \left(-1 \cdot \frac{g}{h}\right) \cdot \frac{-1}{3} + \left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot \frac{-1}{3}\right) - \color{blue}{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)} \cdot \mathsf{PI}\left(\right)\right) \]
    3. mul-1-negN/A

      \[\leadsto 2 \cdot \sin \left(\left(\cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right) \cdot \frac{-1}{3} + \left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot \frac{-1}{3}\right) - \left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot \mathsf{PI}\left(\right)\right) \]
    4. distribute-frac-negN/A

      \[\leadsto 2 \cdot \sin \left(\left(\cos^{-1} \left(\frac{\mathsf{neg}\left(g\right)}{h}\right) \cdot \frac{-1}{3} + \left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot \frac{-1}{3}\right) - \left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot \mathsf{PI}\left(\right)\right) \]
    5. lower-acos.f64N/A

      \[\leadsto 2 \cdot \sin \left(\left(\cos^{-1} \left(\frac{\mathsf{neg}\left(g\right)}{h}\right) \cdot \frac{-1}{3} + \left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot \frac{-1}{3}\right) - \left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot \mathsf{PI}\left(\right)\right) \]
    6. lift-/.f64N/A

      \[\leadsto 2 \cdot \sin \left(\left(\cos^{-1} \left(\frac{\mathsf{neg}\left(g\right)}{h}\right) \cdot \frac{-1}{3} + \left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot \frac{-1}{3}\right) - \left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot \mathsf{PI}\left(\right)\right) \]
    7. lift-neg.f64N/A

      \[\leadsto 2 \cdot \sin \left(\left(\cos^{-1} \left(\frac{-g}{h}\right) \cdot \frac{-1}{3} + \left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot \frac{-1}{3}\right) - \left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot \mathsf{PI}\left(\right)\right) \]
    8. *-commutativeN/A

      \[\leadsto 2 \cdot \sin \left(\left(\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right) + \left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot \frac{-1}{3}\right) - \left(\mathsf{neg}\left(\color{blue}{\frac{1}{2}}\right)\right) \cdot \mathsf{PI}\left(\right)\right) \]
    9. lift-*.f64N/A

      \[\leadsto 2 \cdot \sin \left(\left(\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right) + \left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot \frac{-1}{3}\right) - \left(\mathsf{neg}\left(\color{blue}{\frac{1}{2}}\right)\right) \cdot \mathsf{PI}\left(\right)\right) \]
    10. associate--l+N/A

      \[\leadsto 2 \cdot \sin \left(\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right) + \color{blue}{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot \frac{-1}{3} - \left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot \mathsf{PI}\left(\right)\right)}\right) \]
    11. lower-+.f64N/A

      \[\leadsto 2 \cdot \sin \left(\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right) + \color{blue}{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot \frac{-1}{3} - \left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot \mathsf{PI}\left(\right)\right)}\right) \]
  7. Applied rewrites98.5%

    \[\leadsto 2 \cdot \sin \color{blue}{\left(-0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right) + \left(\pi \cdot -0.6666666666666666 - -0.5 \cdot \pi\right)\right)} \]
  8. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{2 \cdot \sin \left(\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right) + \left(\pi \cdot \frac{-2}{3} - \frac{-1}{2} \cdot \pi\right)\right)} \]
    2. *-commutativeN/A

      \[\leadsto \color{blue}{\sin \left(\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right) + \left(\pi \cdot \frac{-2}{3} - \frac{-1}{2} \cdot \pi\right)\right) \cdot 2} \]
    3. lower-*.f6498.5

      \[\leadsto \color{blue}{\sin \left(-0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right) + \left(\pi \cdot -0.6666666666666666 - -0.5 \cdot \pi\right)\right) \cdot 2} \]
  9. Applied rewrites99.9%

    \[\leadsto \color{blue}{\sin \left(\pi \cdot -0.16666666666666666 - 0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot 2} \]
  10. Add Preprocessing

Alternative 3: 98.4% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \cos \left(-0.3333333333333333 \cdot \left(\left(\pi + \cos^{-1} \left(\frac{-g}{h}\right)\right) + \pi\right)\right) \cdot 2 \end{array} \]
(FPCore (g h)
 :precision binary64
 (* (cos (* -0.3333333333333333 (+ (+ PI (acos (/ (- g) h))) PI))) 2.0))
double code(double g, double h) {
	return cos((-0.3333333333333333 * ((((double) M_PI) + acos((-g / h))) + ((double) M_PI)))) * 2.0;
}
public static double code(double g, double h) {
	return Math.cos((-0.3333333333333333 * ((Math.PI + Math.acos((-g / h))) + Math.PI))) * 2.0;
}
def code(g, h):
	return math.cos((-0.3333333333333333 * ((math.pi + math.acos((-g / h))) + math.pi))) * 2.0
function code(g, h)
	return Float64(cos(Float64(-0.3333333333333333 * Float64(Float64(pi + acos(Float64(Float64(-g) / h))) + pi))) * 2.0)
end
function tmp = code(g, h)
	tmp = cos((-0.3333333333333333 * ((pi + acos((-g / h))) + pi))) * 2.0;
end
code[g_, h_] := N[(N[Cos[N[(-0.3333333333333333 * N[(N[(Pi + N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] + Pi), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]
\begin{array}{l}

\\
\cos \left(-0.3333333333333333 \cdot \left(\left(\pi + \cos^{-1} \left(\frac{-g}{h}\right)\right) + \pi\right)\right) \cdot 2
\end{array}
Derivation
  1. Initial program 98.5%

    \[2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)} \]
    2. *-commutativeN/A

      \[\leadsto \color{blue}{\cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \cdot 2} \]
    3. lower-*.f6498.5

      \[\leadsto \color{blue}{\cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \cdot 2} \]
  4. Applied rewrites98.5%

    \[\leadsto \color{blue}{\cos \left(\frac{\cos^{-1} \left(\frac{-g}{h}\right) + \pi \cdot 2}{-3}\right) \cdot 2} \]
  5. Taylor expanded in g around 0

    \[\leadsto \cos \color{blue}{\left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(-1 \cdot \frac{g}{h}\right) + 2 \cdot \mathsf{PI}\left(\right)\right)\right)} \cdot 2 \]
  6. Step-by-step derivation
    1. mul-1-negN/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right) + 2 \cdot \mathsf{PI}\left(\right)\right)\right) \cdot 2 \]
    2. distribute-frac-negN/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{\mathsf{neg}\left(g\right)}{h}\right) + 2 \cdot \mathsf{PI}\left(\right)\right)\right) \cdot 2 \]
    3. lower-acos.f64N/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{\mathsf{neg}\left(g\right)}{h}\right) + \color{blue}{2} \cdot \mathsf{PI}\left(\right)\right)\right) \cdot 2 \]
    4. lift-/.f64N/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{\mathsf{neg}\left(g\right)}{h}\right) + 2 \cdot \mathsf{PI}\left(\right)\right)\right) \cdot 2 \]
    5. lift-neg.f64N/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{-g}{h}\right) + 2 \cdot \mathsf{PI}\left(\right)\right)\right) \cdot 2 \]
    6. lower-+.f64N/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{-g}{h}\right) + \color{blue}{2 \cdot \mathsf{PI}\left(\right)}\right)\right) \cdot 2 \]
    7. *-commutativeN/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{-g}{h}\right) + \mathsf{PI}\left(\right) \cdot \color{blue}{2}\right)\right) \cdot 2 \]
    8. lift-*.f64N/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{-g}{h}\right) + \mathsf{PI}\left(\right) \cdot \color{blue}{2}\right)\right) \cdot 2 \]
    9. lift-PI.f64N/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{-g}{h}\right) + \pi \cdot 2\right)\right) \cdot 2 \]
    10. lower-*.f6498.5

      \[\leadsto \cos \left(-0.3333333333333333 \cdot \color{blue}{\left(\cos^{-1} \left(\frac{-g}{h}\right) + \pi \cdot 2\right)}\right) \cdot 2 \]
    11. lift-+.f64N/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{-g}{h}\right) + \color{blue}{\pi \cdot 2}\right)\right) \cdot 2 \]
    12. lift-PI.f64N/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{-g}{h}\right) + \mathsf{PI}\left(\right) \cdot 2\right)\right) \cdot 2 \]
    13. lift-*.f64N/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{-g}{h}\right) + \mathsf{PI}\left(\right) \cdot \color{blue}{2}\right)\right) \cdot 2 \]
    14. fp-cancel-sign-sub-invN/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{-g}{h}\right) - \color{blue}{\left(\mathsf{neg}\left(\mathsf{PI}\left(\right)\right)\right) \cdot 2}\right)\right) \cdot 2 \]
    15. distribute-lft-neg-inN/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{-g}{h}\right) - \left(\mathsf{neg}\left(\mathsf{PI}\left(\right) \cdot 2\right)\right)\right)\right) \cdot 2 \]
    16. *-commutativeN/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{-g}{h}\right) - \left(\mathsf{neg}\left(2 \cdot \mathsf{PI}\left(\right)\right)\right)\right)\right) \cdot 2 \]
  7. Applied rewrites98.5%

    \[\leadsto \cos \color{blue}{\left(-0.3333333333333333 \cdot \left(\cos^{-1} \left(\frac{-g}{h}\right) - -2 \cdot \pi\right)\right)} \cdot 2 \]
  8. Step-by-step derivation
    1. lift--.f64N/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{-g}{h}\right) - \color{blue}{-2 \cdot \pi}\right)\right) \cdot 2 \]
    2. lift-PI.f64N/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{-g}{h}\right) - -2 \cdot \mathsf{PI}\left(\right)\right)\right) \cdot 2 \]
    3. lift-*.f64N/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{-g}{h}\right) - -2 \cdot \color{blue}{\mathsf{PI}\left(\right)}\right)\right) \cdot 2 \]
    4. fp-cancel-sub-sign-invN/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{-g}{h}\right) + \color{blue}{\left(\mathsf{neg}\left(-2\right)\right) \cdot \mathsf{PI}\left(\right)}\right)\right) \cdot 2 \]
    5. metadata-evalN/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{-g}{h}\right) + 2 \cdot \mathsf{PI}\left(\right)\right)\right) \cdot 2 \]
    6. count-2-revN/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(\frac{-g}{h}\right) + \left(\mathsf{PI}\left(\right) + \color{blue}{\mathsf{PI}\left(\right)}\right)\right)\right) \cdot 2 \]
    7. associate-+l+N/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\left(\cos^{-1} \left(\frac{-g}{h}\right) + \mathsf{PI}\left(\right)\right) + \color{blue}{\mathsf{PI}\left(\right)}\right)\right) \cdot 2 \]
    8. lift-+.f64N/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\left(\cos^{-1} \left(\frac{-g}{h}\right) + \mathsf{PI}\left(\right)\right) + \mathsf{PI}\left(\right)\right)\right) \cdot 2 \]
    9. lift-PI.f64N/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\left(\cos^{-1} \left(\frac{-g}{h}\right) + \pi\right) + \mathsf{PI}\left(\right)\right)\right) \cdot 2 \]
    10. lift-+.f64N/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\left(\cos^{-1} \left(\frac{-g}{h}\right) + \pi\right) + \color{blue}{\mathsf{PI}\left(\right)}\right)\right) \cdot 2 \]
    11. lift-PI.f6498.5

      \[\leadsto \cos \left(-0.3333333333333333 \cdot \left(\left(\cos^{-1} \left(\frac{-g}{h}\right) + \pi\right) + \pi\right)\right) \cdot 2 \]
    12. lift-PI.f64N/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\left(\cos^{-1} \left(\frac{-g}{h}\right) + \mathsf{PI}\left(\right)\right) + \pi\right)\right) \cdot 2 \]
    13. lift-+.f64N/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\left(\cos^{-1} \left(\frac{-g}{h}\right) + \mathsf{PI}\left(\right)\right) + \pi\right)\right) \cdot 2 \]
    14. +-commutativeN/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\left(\mathsf{PI}\left(\right) + \cos^{-1} \left(\frac{-g}{h}\right)\right) + \pi\right)\right) \cdot 2 \]
    15. lower-+.f64N/A

      \[\leadsto \cos \left(\frac{-1}{3} \cdot \left(\left(\mathsf{PI}\left(\right) + \cos^{-1} \left(\frac{-g}{h}\right)\right) + \pi\right)\right) \cdot 2 \]
    16. lift-PI.f6498.5

      \[\leadsto \cos \left(-0.3333333333333333 \cdot \left(\left(\pi + \cos^{-1} \left(\frac{-g}{h}\right)\right) + \pi\right)\right) \cdot 2 \]
  9. Applied rewrites98.5%

    \[\leadsto \cos \left(-0.3333333333333333 \cdot \left(\left(\pi + \cos^{-1} \left(\frac{-g}{h}\right)\right) + \color{blue}{\pi}\right)\right) \cdot 2 \]
  10. Add Preprocessing

Reproduce

?
herbie shell --seed 2025058 
(FPCore (g h)
  :name "2-ancestry mixing, negative discriminant"
  :precision binary64
  (* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))