2-ancestry mixing, negative discriminant

Percentage Accurate: 98.5% → 100.0%
Time: 11.9s
Alternatives: 4
Speedup: 0.5×

Specification

?
\[\begin{array}{l} \\ 2 \cdot \cos \left(\frac{2 \cdot \mathsf{PI}\left(\right)}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \end{array} \]
(FPCore (g h)
 :precision binary64
 (* 2.0 (cos (+ (/ (* 2.0 (PI)) 3.0) (/ (acos (/ (- g) h)) 3.0)))))
\begin{array}{l}

\\
2 \cdot \cos \left(\frac{2 \cdot \mathsf{PI}\left(\right)}{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 4 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?

\[\begin{array}{l} \\ 2 \cdot \cos \left(\frac{2 \cdot \mathsf{PI}\left(\right)}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \end{array} \]
(FPCore (g h)
 :precision binary64
 (* 2.0 (cos (+ (/ (* 2.0 (PI)) 3.0) (/ (acos (/ (- g) h)) 3.0)))))
\begin{array}{l}

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

Alternative 1: 100.0% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos^{-1} \left(-\frac{g}{h}\right)\\ t_1 := 0.3333333333333333 \cdot t\_0\\ \sin t\_1 \cdot \left(-\sqrt{3}\right) - \cos \left(\sqrt{0.3333333333333333 \cdot t\_1} \cdot \sqrt{t\_0}\right) \end{array} \end{array} \]
(FPCore (g h)
 :precision binary64
 (let* ((t_0 (acos (- (/ g h)))) (t_1 (* 0.3333333333333333 t_0)))
   (-
    (* (sin t_1) (- (sqrt 3.0)))
    (cos (* (sqrt (* 0.3333333333333333 t_1)) (sqrt t_0))))))
double code(double g, double h) {
	double t_0 = acos(-(g / h));
	double t_1 = 0.3333333333333333 * t_0;
	return (sin(t_1) * -sqrt(3.0)) - cos((sqrt((0.3333333333333333 * t_1)) * sqrt(t_0)));
}
real(8) function code(g, h)
    real(8), intent (in) :: g
    real(8), intent (in) :: h
    real(8) :: t_0
    real(8) :: t_1
    t_0 = acos(-(g / h))
    t_1 = 0.3333333333333333d0 * t_0
    code = (sin(t_1) * -sqrt(3.0d0)) - cos((sqrt((0.3333333333333333d0 * t_1)) * sqrt(t_0)))
end function
public static double code(double g, double h) {
	double t_0 = Math.acos(-(g / h));
	double t_1 = 0.3333333333333333 * t_0;
	return (Math.sin(t_1) * -Math.sqrt(3.0)) - Math.cos((Math.sqrt((0.3333333333333333 * t_1)) * Math.sqrt(t_0)));
}
def code(g, h):
	t_0 = math.acos(-(g / h))
	t_1 = 0.3333333333333333 * t_0
	return (math.sin(t_1) * -math.sqrt(3.0)) - math.cos((math.sqrt((0.3333333333333333 * t_1)) * math.sqrt(t_0)))
function code(g, h)
	t_0 = acos(Float64(-Float64(g / h)))
	t_1 = Float64(0.3333333333333333 * t_0)
	return Float64(Float64(sin(t_1) * Float64(-sqrt(3.0))) - cos(Float64(sqrt(Float64(0.3333333333333333 * t_1)) * sqrt(t_0))))
end
function tmp = code(g, h)
	t_0 = acos(-(g / h));
	t_1 = 0.3333333333333333 * t_0;
	tmp = (sin(t_1) * -sqrt(3.0)) - cos((sqrt((0.3333333333333333 * t_1)) * sqrt(t_0)));
end
code[g_, h_] := Block[{t$95$0 = N[ArcCos[(-N[(g / h), $MachinePrecision])], $MachinePrecision]}, Block[{t$95$1 = N[(0.3333333333333333 * t$95$0), $MachinePrecision]}, N[(N[(N[Sin[t$95$1], $MachinePrecision] * (-N[Sqrt[3.0], $MachinePrecision])), $MachinePrecision] - N[Cos[N[(N[Sqrt[N[(0.3333333333333333 * t$95$1), $MachinePrecision]], $MachinePrecision] * N[Sqrt[t$95$0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos^{-1} \left(-\frac{g}{h}\right)\\
t_1 := 0.3333333333333333 \cdot t\_0\\
\sin t\_1 \cdot \left(-\sqrt{3}\right) - \cos \left(\sqrt{0.3333333333333333 \cdot t\_1} \cdot \sqrt{t\_0}\right)
\end{array}
\end{array}
Derivation
  1. Initial program 98.5%

    \[2 \cdot \cos \left(\frac{2 \cdot \mathsf{PI}\left(\right)}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
  2. Add Preprocessing
  3. Applied rewrites98.4%

    \[\leadsto 2 \cdot \color{blue}{\mathsf{fma}\left(0.25 - \frac{\sqrt{3}}{2} \cdot \frac{\sqrt{3}}{2}, \cos \left(\cos^{-1} \left(\frac{g}{-h}\right) \cdot 0.3333333333333333\right), \sin \left(\cos^{-1} \left(\frac{g}{-h}\right) \cdot 0.3333333333333333\right) \cdot \left(-2 \cdot \left(\frac{\sqrt{3}}{2} \cdot 0.5\right)\right)\right)} \]
  4. Applied rewrites99.9%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\sin \left(\cos^{-1} \left(-\frac{g}{h}\right) \cdot 0.3333333333333333\right) \cdot \left(\sqrt{3} \cdot -0.5\right), 2, \cos \left(\cos^{-1} \left(-\frac{g}{h}\right) \cdot 0.3333333333333333\right) \cdot -1\right)} \]
  5. Applied rewrites99.9%

    \[\leadsto \color{blue}{\sin \left(0.3333333333333333 \cdot \cos^{-1} \left(-\frac{g}{h}\right)\right) \cdot \left(-\sqrt{3}\right) - \cos \left(0.3333333333333333 \cdot \cos^{-1} \left(-\frac{g}{h}\right)\right)} \]
  6. Step-by-step derivation
    1. lift-/.f64N/A

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

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

      \[\leadsto \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{3}\right)\right) - \cos \left(\frac{1}{3} \cdot \color{blue}{\cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right)}\right) \]
    4. lift-*.f6499.9

      \[\leadsto \sin \left(0.3333333333333333 \cdot \cos^{-1} \left(-\frac{g}{h}\right)\right) \cdot \left(-\sqrt{3}\right) - \cos \color{blue}{\left(0.3333333333333333 \cdot \cos^{-1} \left(-\frac{g}{h}\right)\right)} \]
    5. rem-square-sqrtN/A

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

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

      \[\leadsto \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{3}\right)\right) - \cos \left(\sqrt{\frac{1}{3} \cdot \cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right)} \cdot \sqrt{\color{blue}{\frac{1}{3} \cdot \cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right)}}\right) \]
    8. sqrt-prodN/A

      \[\leadsto \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{3}\right)\right) - \cos \left(\sqrt{\frac{1}{3} \cdot \cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right)} \cdot \color{blue}{\left(\sqrt{\frac{1}{3}} \cdot \sqrt{\cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right)}\right)}\right) \]
    9. associate-*r*N/A

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

      \[\leadsto \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{3}\right)\right) - \cos \color{blue}{\left(\left(\sqrt{\frac{1}{3} \cdot \cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right)} \cdot \sqrt{\frac{1}{3}}\right) \cdot \sqrt{\cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right)}\right)} \]
  7. Applied rewrites100.0%

    \[\leadsto \sin \left(0.3333333333333333 \cdot \cos^{-1} \left(-\frac{g}{h}\right)\right) \cdot \left(-\sqrt{3}\right) - \cos \color{blue}{\left(\sqrt{\left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot 0.3333333333333333} \cdot \sqrt{\cos^{-1} \left(\frac{-g}{h}\right)}\right)} \]
  8. Final simplification100.0%

    \[\leadsto \sin \left(0.3333333333333333 \cdot \cos^{-1} \left(-\frac{g}{h}\right)\right) \cdot \left(-\sqrt{3}\right) - \cos \left(\sqrt{0.3333333333333333 \cdot \left(0.3333333333333333 \cdot \cos^{-1} \left(-\frac{g}{h}\right)\right)} \cdot \sqrt{\cos^{-1} \left(-\frac{g}{h}\right)}\right) \]
  9. Add Preprocessing

Alternative 2: 100.0% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 0.3333333333333333 \cdot \cos^{-1} \left(-\frac{g}{h}\right)\\ \sin t\_0 \cdot \left(-\sqrt{3}\right) - \cos t\_0 \end{array} \end{array} \]
(FPCore (g h)
 :precision binary64
 (let* ((t_0 (* 0.3333333333333333 (acos (- (/ g h))))))
   (- (* (sin t_0) (- (sqrt 3.0))) (cos t_0))))
double code(double g, double h) {
	double t_0 = 0.3333333333333333 * acos(-(g / h));
	return (sin(t_0) * -sqrt(3.0)) - cos(t_0);
}
real(8) function code(g, h)
    real(8), intent (in) :: g
    real(8), intent (in) :: h
    real(8) :: t_0
    t_0 = 0.3333333333333333d0 * acos(-(g / h))
    code = (sin(t_0) * -sqrt(3.0d0)) - cos(t_0)
end function
public static double code(double g, double h) {
	double t_0 = 0.3333333333333333 * Math.acos(-(g / h));
	return (Math.sin(t_0) * -Math.sqrt(3.0)) - Math.cos(t_0);
}
def code(g, h):
	t_0 = 0.3333333333333333 * math.acos(-(g / h))
	return (math.sin(t_0) * -math.sqrt(3.0)) - math.cos(t_0)
function code(g, h)
	t_0 = Float64(0.3333333333333333 * acos(Float64(-Float64(g / h))))
	return Float64(Float64(sin(t_0) * Float64(-sqrt(3.0))) - cos(t_0))
end
function tmp = code(g, h)
	t_0 = 0.3333333333333333 * acos(-(g / h));
	tmp = (sin(t_0) * -sqrt(3.0)) - cos(t_0);
end
code[g_, h_] := Block[{t$95$0 = N[(0.3333333333333333 * N[ArcCos[(-N[(g / h), $MachinePrecision])], $MachinePrecision]), $MachinePrecision]}, N[(N[(N[Sin[t$95$0], $MachinePrecision] * (-N[Sqrt[3.0], $MachinePrecision])), $MachinePrecision] - N[Cos[t$95$0], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := 0.3333333333333333 \cdot \cos^{-1} \left(-\frac{g}{h}\right)\\
\sin t\_0 \cdot \left(-\sqrt{3}\right) - \cos t\_0
\end{array}
\end{array}
Derivation
  1. Initial program 98.5%

    \[2 \cdot \cos \left(\frac{2 \cdot \mathsf{PI}\left(\right)}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
  2. Add Preprocessing
  3. Applied rewrites98.4%

    \[\leadsto 2 \cdot \color{blue}{\mathsf{fma}\left(0.25 - \frac{\sqrt{3}}{2} \cdot \frac{\sqrt{3}}{2}, \cos \left(\cos^{-1} \left(\frac{g}{-h}\right) \cdot 0.3333333333333333\right), \sin \left(\cos^{-1} \left(\frac{g}{-h}\right) \cdot 0.3333333333333333\right) \cdot \left(-2 \cdot \left(\frac{\sqrt{3}}{2} \cdot 0.5\right)\right)\right)} \]
  4. Applied rewrites99.9%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\sin \left(\cos^{-1} \left(-\frac{g}{h}\right) \cdot 0.3333333333333333\right) \cdot \left(\sqrt{3} \cdot -0.5\right), 2, \cos \left(\cos^{-1} \left(-\frac{g}{h}\right) \cdot 0.3333333333333333\right) \cdot -1\right)} \]
  5. Applied rewrites99.9%

    \[\leadsto \color{blue}{\sin \left(0.3333333333333333 \cdot \cos^{-1} \left(-\frac{g}{h}\right)\right) \cdot \left(-\sqrt{3}\right) - \cos \left(0.3333333333333333 \cdot \cos^{-1} \left(-\frac{g}{h}\right)\right)} \]
  6. Add Preprocessing

Alternative 3: 100.0% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 0.3333333333333333 \cdot \cos^{-1} \left(-\frac{g}{h}\right)\\ -\mathsf{fma}\left(\sin t\_0, \sqrt{3}, \cos t\_0\right) \end{array} \end{array} \]
(FPCore (g h)
 :precision binary64
 (let* ((t_0 (* 0.3333333333333333 (acos (- (/ g h))))))
   (- (fma (sin t_0) (sqrt 3.0) (cos t_0)))))
double code(double g, double h) {
	double t_0 = 0.3333333333333333 * acos(-(g / h));
	return -fma(sin(t_0), sqrt(3.0), cos(t_0));
}
function code(g, h)
	t_0 = Float64(0.3333333333333333 * acos(Float64(-Float64(g / h))))
	return Float64(-fma(sin(t_0), sqrt(3.0), cos(t_0)))
end
code[g_, h_] := Block[{t$95$0 = N[(0.3333333333333333 * N[ArcCos[(-N[(g / h), $MachinePrecision])], $MachinePrecision]), $MachinePrecision]}, (-N[(N[Sin[t$95$0], $MachinePrecision] * N[Sqrt[3.0], $MachinePrecision] + N[Cos[t$95$0], $MachinePrecision]), $MachinePrecision])]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := 0.3333333333333333 \cdot \cos^{-1} \left(-\frac{g}{h}\right)\\
-\mathsf{fma}\left(\sin t\_0, \sqrt{3}, \cos t\_0\right)
\end{array}
\end{array}
Derivation
  1. Initial program 98.5%

    \[2 \cdot \cos \left(\frac{2 \cdot \mathsf{PI}\left(\right)}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
  2. Add Preprocessing
  3. Applied rewrites98.4%

    \[\leadsto 2 \cdot \color{blue}{\mathsf{fma}\left(0.25 - \frac{\sqrt{3}}{2} \cdot \frac{\sqrt{3}}{2}, \cos \left(\cos^{-1} \left(\frac{g}{-h}\right) \cdot 0.3333333333333333\right), \sin \left(\cos^{-1} \left(\frac{g}{-h}\right) \cdot 0.3333333333333333\right) \cdot \left(-2 \cdot \left(\frac{\sqrt{3}}{2} \cdot 0.5\right)\right)\right)} \]
  4. Taylor expanded in g around 0

    \[\leadsto \color{blue}{2 \cdot \left(\frac{-1}{2} \cdot \left(\sin \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right) \cdot \sqrt{3}\right) + \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right) \cdot \left(\frac{1}{4} - \frac{1}{4} \cdot {\left(\sqrt{3}\right)}^{2}\right)\right)} \]
  5. Applied rewrites99.9%

    \[\leadsto \color{blue}{-\mathsf{fma}\left(\sin \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\right), \sqrt{3}, \cos \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\right)\right)} \]
  6. Final simplification99.9%

    \[\leadsto -\mathsf{fma}\left(\sin \left(0.3333333333333333 \cdot \cos^{-1} \left(-\frac{g}{h}\right)\right), \sqrt{3}, \cos \left(0.3333333333333333 \cdot \cos^{-1} \left(-\frac{g}{h}\right)\right)\right) \]
  7. Add Preprocessing

Alternative 4: 98.5% accurate, 1.1× speedup?

\[\begin{array}{l} \\ 2 \cdot \cos \left(0.3333333333333333 \cdot \mathsf{fma}\left(2, \mathsf{PI}\left(\right), \cos^{-1} \left(-\frac{g}{h}\right)\right)\right) \end{array} \]
(FPCore (g h)
 :precision binary64
 (* 2.0 (cos (* 0.3333333333333333 (fma 2.0 (PI) (acos (- (/ g h))))))))
\begin{array}{l}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto 2 \cdot \cos \left(0.3333333333333333 \cdot \color{blue}{\mathsf{fma}\left(2, \mathsf{PI}\left(\right), \cos^{-1} \left(\frac{-g}{h}\right)\right)}\right) \]
    17. lift-/.f64N/A

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

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

    \[\leadsto 2 \cdot \cos \color{blue}{\left(0.3333333333333333 \cdot \mathsf{fma}\left(2, \mathsf{PI}\left(\right), \cos^{-1} \left(\frac{g}{-h}\right)\right)\right)} \]
  5. Final simplification98.5%

    \[\leadsto 2 \cdot \cos \left(0.3333333333333333 \cdot \mathsf{fma}\left(2, \mathsf{PI}\left(\right), \cos^{-1} \left(-\frac{g}{h}\right)\right)\right) \]
  6. Add Preprocessing

Reproduce

?
herbie shell --seed 2024216 
(FPCore (g h)
  :name "2-ancestry mixing, negative discriminant"
  :precision binary64
  (* 2.0 (cos (+ (/ (* 2.0 (PI)) 3.0) (/ (acos (/ (- g) h)) 3.0)))))