(cos (* (atan (* (tan (* (- (+ z2 z2) -1/2) PI)) (/ z0 z1))) 2))

Percentage Accurate: 67.3% → 99.4%
Time: 6.8s
Alternatives: 6
Speedup: 1.0×

Specification

?
\[\cos \left(\tan^{-1} \left(\tan \left(\left(\left(z2 + z2\right) - -0.5\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
(FPCore (z2 z0 z1)
  :precision binary64
  (cos (* (atan (* (tan (* (- (+ z2 z2) -0.5) PI)) (/ z0 z1))) 2.0)))
double code(double z2, double z0, double z1) {
	return cos((atan((tan((((z2 + z2) - -0.5) * ((double) M_PI))) * (z0 / z1))) * 2.0));
}
public static double code(double z2, double z0, double z1) {
	return Math.cos((Math.atan((Math.tan((((z2 + z2) - -0.5) * Math.PI)) * (z0 / z1))) * 2.0));
}
def code(z2, z0, z1):
	return math.cos((math.atan((math.tan((((z2 + z2) - -0.5) * math.pi)) * (z0 / z1))) * 2.0))
function code(z2, z0, z1)
	return cos(Float64(atan(Float64(tan(Float64(Float64(Float64(z2 + z2) - -0.5) * pi)) * Float64(z0 / z1))) * 2.0))
end
function tmp = code(z2, z0, z1)
	tmp = cos((atan((tan((((z2 + z2) - -0.5) * pi)) * (z0 / z1))) * 2.0));
end
code[z2_, z0_, z1_] := N[Cos[N[(N[ArcTan[N[(N[Tan[N[(N[(N[(z2 + z2), $MachinePrecision] - -0.5), $MachinePrecision] * Pi), $MachinePrecision]], $MachinePrecision] * N[(z0 / z1), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision]
\cos \left(\tan^{-1} \left(\tan \left(\left(\left(z2 + z2\right) - -0.5\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right) \cdot 2\right)

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 6 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: 67.3% accurate, 1.0× speedup?

\[\cos \left(\tan^{-1} \left(\tan \left(\left(\left(z2 + z2\right) - -0.5\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
(FPCore (z2 z0 z1)
  :precision binary64
  (cos (* (atan (* (tan (* (- (+ z2 z2) -0.5) PI)) (/ z0 z1))) 2.0)))
double code(double z2, double z0, double z1) {
	return cos((atan((tan((((z2 + z2) - -0.5) * ((double) M_PI))) * (z0 / z1))) * 2.0));
}
public static double code(double z2, double z0, double z1) {
	return Math.cos((Math.atan((Math.tan((((z2 + z2) - -0.5) * Math.PI)) * (z0 / z1))) * 2.0));
}
def code(z2, z0, z1):
	return math.cos((math.atan((math.tan((((z2 + z2) - -0.5) * math.pi)) * (z0 / z1))) * 2.0))
function code(z2, z0, z1)
	return cos(Float64(atan(Float64(tan(Float64(Float64(Float64(z2 + z2) - -0.5) * pi)) * Float64(z0 / z1))) * 2.0))
end
function tmp = code(z2, z0, z1)
	tmp = cos((atan((tan((((z2 + z2) - -0.5) * pi)) * (z0 / z1))) * 2.0));
end
code[z2_, z0_, z1_] := N[Cos[N[(N[ArcTan[N[(N[Tan[N[(N[(N[(z2 + z2), $MachinePrecision] - -0.5), $MachinePrecision] * Pi), $MachinePrecision]], $MachinePrecision] * N[(z0 / z1), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision]
\cos \left(\tan^{-1} \left(\tan \left(\left(\left(z2 + z2\right) - -0.5\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right) \cdot 2\right)

Alternative 1: 99.4% accurate, 0.7× speedup?

\[\begin{array}{l} t_0 := \cos \left(\tan^{-1} \left(\frac{\left(\left(\pi - \frac{\pi}{0}\right) \cdot \left(z2 + z2\right) - \tan \left(\pi \cdot -0.5\right)\right) \cdot z0}{z1}\right) \cdot 2\right)\\ \mathbf{if}\;z2 \leq -2.8 \cdot 10^{+21}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;z2 \leq 20000000:\\ \;\;\;\;\cos \left(\tan^{-1} \left(\frac{\sin \left(\left(-\pi\right) \cdot \left(z2 + z2\right) + \pi \cdot 0.5\right) \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \]
(FPCore (z2 z0 z1)
  :precision binary64
  (let* ((t_0
        (cos
         (*
          (atan
           (/
            (*
             (- (* (- PI (/ PI 0.0)) (+ z2 z2)) (tan (* PI -0.5)))
             z0)
            z1))
          2.0))))
  (if (<= z2 -2.8e+21)
    t_0
    (if (<= z2 20000000.0)
      (cos
       (*
        (atan
         (/
          (* (sin (+ (* (- PI) (+ z2 z2)) (* PI 0.5))) z0)
          (* (- (sin (* PI (+ z2 z2)))) z1)))
        2.0))
      t_0))))
double code(double z2, double z0, double z1) {
	double t_0 = cos((atan((((((((double) M_PI) - (((double) M_PI) / 0.0)) * (z2 + z2)) - tan((((double) M_PI) * -0.5))) * z0) / z1)) * 2.0));
	double tmp;
	if (z2 <= -2.8e+21) {
		tmp = t_0;
	} else if (z2 <= 20000000.0) {
		tmp = cos((atan(((sin(((-((double) M_PI) * (z2 + z2)) + (((double) M_PI) * 0.5))) * z0) / (-sin((((double) M_PI) * (z2 + z2))) * z1))) * 2.0));
	} else {
		tmp = t_0;
	}
	return tmp;
}
public static double code(double z2, double z0, double z1) {
	double t_0 = Math.cos((Math.atan((((((Math.PI - (Math.PI / 0.0)) * (z2 + z2)) - Math.tan((Math.PI * -0.5))) * z0) / z1)) * 2.0));
	double tmp;
	if (z2 <= -2.8e+21) {
		tmp = t_0;
	} else if (z2 <= 20000000.0) {
		tmp = Math.cos((Math.atan(((Math.sin(((-Math.PI * (z2 + z2)) + (Math.PI * 0.5))) * z0) / (-Math.sin((Math.PI * (z2 + z2))) * z1))) * 2.0));
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(z2, z0, z1):
	t_0 = math.cos((math.atan((((((math.pi - (math.pi / 0.0)) * (z2 + z2)) - math.tan((math.pi * -0.5))) * z0) / z1)) * 2.0))
	tmp = 0
	if z2 <= -2.8e+21:
		tmp = t_0
	elif z2 <= 20000000.0:
		tmp = math.cos((math.atan(((math.sin(((-math.pi * (z2 + z2)) + (math.pi * 0.5))) * z0) / (-math.sin((math.pi * (z2 + z2))) * z1))) * 2.0))
	else:
		tmp = t_0
	return tmp
function code(z2, z0, z1)
	t_0 = cos(Float64(atan(Float64(Float64(Float64(Float64(Float64(pi - Float64(pi / 0.0)) * Float64(z2 + z2)) - tan(Float64(pi * -0.5))) * z0) / z1)) * 2.0))
	tmp = 0.0
	if (z2 <= -2.8e+21)
		tmp = t_0;
	elseif (z2 <= 20000000.0)
		tmp = cos(Float64(atan(Float64(Float64(sin(Float64(Float64(Float64(-pi) * Float64(z2 + z2)) + Float64(pi * 0.5))) * z0) / Float64(Float64(-sin(Float64(pi * Float64(z2 + z2)))) * z1))) * 2.0));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(z2, z0, z1)
	t_0 = cos((atan((((((pi - (pi / 0.0)) * (z2 + z2)) - tan((pi * -0.5))) * z0) / z1)) * 2.0));
	tmp = 0.0;
	if (z2 <= -2.8e+21)
		tmp = t_0;
	elseif (z2 <= 20000000.0)
		tmp = cos((atan(((sin(((-pi * (z2 + z2)) + (pi * 0.5))) * z0) / (-sin((pi * (z2 + z2))) * z1))) * 2.0));
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[z2_, z0_, z1_] := Block[{t$95$0 = N[Cos[N[(N[ArcTan[N[(N[(N[(N[(N[(Pi - N[(Pi / 0.0), $MachinePrecision]), $MachinePrecision] * N[(z2 + z2), $MachinePrecision]), $MachinePrecision] - N[Tan[N[(Pi * -0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * z0), $MachinePrecision] / z1), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[z2, -2.8e+21], t$95$0, If[LessEqual[z2, 20000000.0], N[Cos[N[(N[ArcTan[N[(N[(N[Sin[N[(N[((-Pi) * N[(z2 + z2), $MachinePrecision]), $MachinePrecision] + N[(Pi * 0.5), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * z0), $MachinePrecision] / N[((-N[Sin[N[(Pi * N[(z2 + z2), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]) * z1), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision], t$95$0]]]
\begin{array}{l}
t_0 := \cos \left(\tan^{-1} \left(\frac{\left(\left(\pi - \frac{\pi}{0}\right) \cdot \left(z2 + z2\right) - \tan \left(\pi \cdot -0.5\right)\right) \cdot z0}{z1}\right) \cdot 2\right)\\
\mathbf{if}\;z2 \leq -2.8 \cdot 10^{+21}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;z2 \leq 20000000:\\
\;\;\;\;\cos \left(\tan^{-1} \left(\frac{\sin \left(\left(-\pi\right) \cdot \left(z2 + z2\right) + \pi \cdot 0.5\right) \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right)\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z2 < -2.8e21 or 2e7 < z2

    1. Initial program 67.3%

      \[\cos \left(\tan^{-1} \left(\tan \left(\left(\left(z2 + z2\right) - -0.5\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
    2. Taylor expanded in z2 around 0

      \[\leadsto \cos \left(\tan^{-1} \left(\color{blue}{\left(z2 \cdot \left(2 \cdot \pi - -2 \cdot \frac{\pi \cdot {\sin \left(\frac{1}{2} \cdot \pi\right)}^{2}}{{\cos \left(\frac{1}{2} \cdot \pi\right)}^{2}}\right) + \frac{\sin \left(\frac{1}{2} \cdot \pi\right)}{\cos \left(\frac{1}{2} \cdot \pi\right)}\right)} \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
    3. Step-by-step derivation
      1. lower-+.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \left(\left(z2 \cdot \left(2 \cdot \mathsf{PI}\left(\right) - -2 \cdot \frac{\mathsf{PI}\left(\right) \cdot {\sin \left(\frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)}^{2}}{{\cos \left(\frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)}^{2}}\right) + \color{blue}{\frac{\sin \left(\frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)}{\cos \left(\frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)}}\right) \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
    4. Applied rewrites78.7%

      \[\leadsto \cos \left(\tan^{-1} \left(\color{blue}{\left(z2 \cdot \left(2 \cdot \pi - -2 \cdot \frac{\pi \cdot {\sin \left(0.5 \cdot \pi\right)}^{2}}{{\cos \left(0.5 \cdot \pi\right)}^{2}}\right) + \frac{\sin \left(0.5 \cdot \pi\right)}{\cos \left(0.5 \cdot \pi\right)}\right)} \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
    5. Applied rewrites79.2%

      \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\left(\left(2 \cdot \left(\pi + \left(\tan \left(0.5 \cdot \pi\right) \cdot \tan \left(0.5 \cdot \pi\right)\right) \cdot \pi\right)\right) \cdot z2 - \tan \left(\pi \cdot -0.5\right)\right) \cdot z0}{z1}\right)} \cdot 2\right) \]
    6. Applied rewrites84.0%

      \[\leadsto \cos \left(\tan^{-1} \left(\frac{\left(\left(2 \cdot \left(\pi + \frac{\cos \pi \cdot 0.5 - 0.5}{\cos \pi \cdot -0.5 - 0.5} \cdot \pi\right)\right) \cdot z2 - \tan \left(\pi \cdot -0.5\right)\right) \cdot z0}{z1}\right) \cdot 2\right) \]
    7. Applied rewrites84.0%

      \[\leadsto \cos \left(\tan^{-1} \left(\frac{\left(\left(\pi - \frac{\pi}{0}\right) \cdot \left(z2 + z2\right) - \tan \color{blue}{\left(\pi \cdot -0.5\right)}\right) \cdot z0}{z1}\right) \cdot 2\right) \]

    if -2.8e21 < z2 < 2e7

    1. Initial program 67.3%

      \[\cos \left(\tan^{-1} \left(\tan \left(\left(\left(z2 + z2\right) - -0.5\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
    2. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\tan \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right)} \cdot 2\right) \]
      2. lift-tan.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \left(\color{blue}{\tan \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)} \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
      3. tan-quotN/A

        \[\leadsto \cos \left(\tan^{-1} \left(\color{blue}{\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}{\cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}} \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
      4. lift-/.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}{\cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)} \cdot \color{blue}{\frac{z0}{z1}}\right) \cdot 2\right) \]
      5. frac-timesN/A

        \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z0}{\cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z1}\right)} \cdot 2\right) \]
      6. *-commutativeN/A

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z0}{\color{blue}{z1 \cdot \cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}}\right) \cdot 2\right) \]
      7. lower-/.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z0}{z1 \cdot \cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}\right)} \cdot 2\right) \]
    3. Applied rewrites76.5%

      \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\cos \left(\pi \cdot \left(z2 + z2\right)\right) \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right)} \cdot 2\right) \]
    4. Step-by-step derivation
      1. lift-cos.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\color{blue}{\cos \left(\pi \cdot \left(z2 + z2\right)\right)} \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right) \]
      2. cos-neg-revN/A

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\color{blue}{\cos \left(\mathsf{neg}\left(\pi \cdot \left(z2 + z2\right)\right)\right)} \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right) \]
      3. sin-+PI/2-revN/A

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\color{blue}{\sin \left(\left(\mathsf{neg}\left(\pi \cdot \left(z2 + z2\right)\right)\right) + \frac{\mathsf{PI}\left(\right)}{2}\right)} \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right) \]
      4. lower-sin.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\color{blue}{\sin \left(\left(\mathsf{neg}\left(\pi \cdot \left(z2 + z2\right)\right)\right) + \frac{\mathsf{PI}\left(\right)}{2}\right)} \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right) \]
      5. lower-+.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \color{blue}{\left(\left(\mathsf{neg}\left(\pi \cdot \left(z2 + z2\right)\right)\right) + \frac{\mathsf{PI}\left(\right)}{2}\right)} \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right) \]
      6. lift-*.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\left(\mathsf{neg}\left(\color{blue}{\pi \cdot \left(z2 + z2\right)}\right)\right) + \frac{\mathsf{PI}\left(\right)}{2}\right) \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right) \]
      7. distribute-lft-neg-inN/A

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\color{blue}{\left(\mathsf{neg}\left(\pi\right)\right) \cdot \left(z2 + z2\right)} + \frac{\mathsf{PI}\left(\right)}{2}\right) \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right) \]
      8. lower-*.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\color{blue}{\left(\mathsf{neg}\left(\pi\right)\right) \cdot \left(z2 + z2\right)} + \frac{\mathsf{PI}\left(\right)}{2}\right) \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right) \]
      9. lower-neg.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\color{blue}{\left(-\pi\right)} \cdot \left(z2 + z2\right) + \frac{\mathsf{PI}\left(\right)}{2}\right) \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right) \]
      10. lift-PI.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\left(-\pi\right) \cdot \left(z2 + z2\right) + \frac{\color{blue}{\pi}}{2}\right) \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right) \]
      11. mult-flipN/A

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\left(-\pi\right) \cdot \left(z2 + z2\right) + \color{blue}{\pi \cdot \frac{1}{2}}\right) \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right) \]
      12. metadata-evalN/A

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\left(-\pi\right) \cdot \left(z2 + z2\right) + \pi \cdot \color{blue}{\frac{1}{2}}\right) \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right) \]
      13. lower-*.f6476.5%

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\left(-\pi\right) \cdot \left(z2 + z2\right) + \color{blue}{\pi \cdot 0.5}\right) \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right) \]
    5. Applied rewrites76.5%

      \[\leadsto \cos \left(\tan^{-1} \left(\frac{\color{blue}{\sin \left(\left(-\pi\right) \cdot \left(z2 + z2\right) + \pi \cdot 0.5\right)} \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right) \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 2: 99.4% accurate, 0.7× speedup?

\[\begin{array}{l} t_0 := \pi \cdot \left(z2 + z2\right)\\ t_1 := \cos \left(\tan^{-1} \left(\frac{\left(\left(\pi - \frac{\pi}{0}\right) \cdot \left(z2 + z2\right) - \tan \left(\pi \cdot -0.5\right)\right) \cdot z0}{z1}\right) \cdot 2\right)\\ \mathbf{if}\;z2 \leq -2.8 \cdot 10^{+21}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;z2 \leq 20000000:\\ \;\;\;\;\cos \left(\tan^{-1} \left(\frac{\cos t\_0 \cdot z0}{\left(-\sin t\_0\right) \cdot z1}\right) \cdot 2\right)\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \]
(FPCore (z2 z0 z1)
  :precision binary64
  (let* ((t_0 (* PI (+ z2 z2)))
       (t_1
        (cos
         (*
          (atan
           (/
            (*
             (- (* (- PI (/ PI 0.0)) (+ z2 z2)) (tan (* PI -0.5)))
             z0)
            z1))
          2.0))))
  (if (<= z2 -2.8e+21)
    t_1
    (if (<= z2 20000000.0)
      (cos (* (atan (/ (* (cos t_0) z0) (* (- (sin t_0)) z1))) 2.0))
      t_1))))
double code(double z2, double z0, double z1) {
	double t_0 = ((double) M_PI) * (z2 + z2);
	double t_1 = cos((atan((((((((double) M_PI) - (((double) M_PI) / 0.0)) * (z2 + z2)) - tan((((double) M_PI) * -0.5))) * z0) / z1)) * 2.0));
	double tmp;
	if (z2 <= -2.8e+21) {
		tmp = t_1;
	} else if (z2 <= 20000000.0) {
		tmp = cos((atan(((cos(t_0) * z0) / (-sin(t_0) * z1))) * 2.0));
	} else {
		tmp = t_1;
	}
	return tmp;
}
public static double code(double z2, double z0, double z1) {
	double t_0 = Math.PI * (z2 + z2);
	double t_1 = Math.cos((Math.atan((((((Math.PI - (Math.PI / 0.0)) * (z2 + z2)) - Math.tan((Math.PI * -0.5))) * z0) / z1)) * 2.0));
	double tmp;
	if (z2 <= -2.8e+21) {
		tmp = t_1;
	} else if (z2 <= 20000000.0) {
		tmp = Math.cos((Math.atan(((Math.cos(t_0) * z0) / (-Math.sin(t_0) * z1))) * 2.0));
	} else {
		tmp = t_1;
	}
	return tmp;
}
def code(z2, z0, z1):
	t_0 = math.pi * (z2 + z2)
	t_1 = math.cos((math.atan((((((math.pi - (math.pi / 0.0)) * (z2 + z2)) - math.tan((math.pi * -0.5))) * z0) / z1)) * 2.0))
	tmp = 0
	if z2 <= -2.8e+21:
		tmp = t_1
	elif z2 <= 20000000.0:
		tmp = math.cos((math.atan(((math.cos(t_0) * z0) / (-math.sin(t_0) * z1))) * 2.0))
	else:
		tmp = t_1
	return tmp
function code(z2, z0, z1)
	t_0 = Float64(pi * Float64(z2 + z2))
	t_1 = cos(Float64(atan(Float64(Float64(Float64(Float64(Float64(pi - Float64(pi / 0.0)) * Float64(z2 + z2)) - tan(Float64(pi * -0.5))) * z0) / z1)) * 2.0))
	tmp = 0.0
	if (z2 <= -2.8e+21)
		tmp = t_1;
	elseif (z2 <= 20000000.0)
		tmp = cos(Float64(atan(Float64(Float64(cos(t_0) * z0) / Float64(Float64(-sin(t_0)) * z1))) * 2.0));
	else
		tmp = t_1;
	end
	return tmp
end
function tmp_2 = code(z2, z0, z1)
	t_0 = pi * (z2 + z2);
	t_1 = cos((atan((((((pi - (pi / 0.0)) * (z2 + z2)) - tan((pi * -0.5))) * z0) / z1)) * 2.0));
	tmp = 0.0;
	if (z2 <= -2.8e+21)
		tmp = t_1;
	elseif (z2 <= 20000000.0)
		tmp = cos((atan(((cos(t_0) * z0) / (-sin(t_0) * z1))) * 2.0));
	else
		tmp = t_1;
	end
	tmp_2 = tmp;
end
code[z2_, z0_, z1_] := Block[{t$95$0 = N[(Pi * N[(z2 + z2), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[Cos[N[(N[ArcTan[N[(N[(N[(N[(N[(Pi - N[(Pi / 0.0), $MachinePrecision]), $MachinePrecision] * N[(z2 + z2), $MachinePrecision]), $MachinePrecision] - N[Tan[N[(Pi * -0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * z0), $MachinePrecision] / z1), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[z2, -2.8e+21], t$95$1, If[LessEqual[z2, 20000000.0], N[Cos[N[(N[ArcTan[N[(N[(N[Cos[t$95$0], $MachinePrecision] * z0), $MachinePrecision] / N[((-N[Sin[t$95$0], $MachinePrecision]) * z1), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision], t$95$1]]]]
\begin{array}{l}
t_0 := \pi \cdot \left(z2 + z2\right)\\
t_1 := \cos \left(\tan^{-1} \left(\frac{\left(\left(\pi - \frac{\pi}{0}\right) \cdot \left(z2 + z2\right) - \tan \left(\pi \cdot -0.5\right)\right) \cdot z0}{z1}\right) \cdot 2\right)\\
\mathbf{if}\;z2 \leq -2.8 \cdot 10^{+21}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;z2 \leq 20000000:\\
\;\;\;\;\cos \left(\tan^{-1} \left(\frac{\cos t\_0 \cdot z0}{\left(-\sin t\_0\right) \cdot z1}\right) \cdot 2\right)\\

\mathbf{else}:\\
\;\;\;\;t\_1\\


\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z2 < -2.8e21 or 2e7 < z2

    1. Initial program 67.3%

      \[\cos \left(\tan^{-1} \left(\tan \left(\left(\left(z2 + z2\right) - -0.5\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
    2. Taylor expanded in z2 around 0

      \[\leadsto \cos \left(\tan^{-1} \left(\color{blue}{\left(z2 \cdot \left(2 \cdot \pi - -2 \cdot \frac{\pi \cdot {\sin \left(\frac{1}{2} \cdot \pi\right)}^{2}}{{\cos \left(\frac{1}{2} \cdot \pi\right)}^{2}}\right) + \frac{\sin \left(\frac{1}{2} \cdot \pi\right)}{\cos \left(\frac{1}{2} \cdot \pi\right)}\right)} \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
    3. Step-by-step derivation
      1. lower-+.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \left(\left(z2 \cdot \left(2 \cdot \mathsf{PI}\left(\right) - -2 \cdot \frac{\mathsf{PI}\left(\right) \cdot {\sin \left(\frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)}^{2}}{{\cos \left(\frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)}^{2}}\right) + \color{blue}{\frac{\sin \left(\frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)}{\cos \left(\frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)}}\right) \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
    4. Applied rewrites78.7%

      \[\leadsto \cos \left(\tan^{-1} \left(\color{blue}{\left(z2 \cdot \left(2 \cdot \pi - -2 \cdot \frac{\pi \cdot {\sin \left(0.5 \cdot \pi\right)}^{2}}{{\cos \left(0.5 \cdot \pi\right)}^{2}}\right) + \frac{\sin \left(0.5 \cdot \pi\right)}{\cos \left(0.5 \cdot \pi\right)}\right)} \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
    5. Applied rewrites79.2%

      \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\left(\left(2 \cdot \left(\pi + \left(\tan \left(0.5 \cdot \pi\right) \cdot \tan \left(0.5 \cdot \pi\right)\right) \cdot \pi\right)\right) \cdot z2 - \tan \left(\pi \cdot -0.5\right)\right) \cdot z0}{z1}\right)} \cdot 2\right) \]
    6. Applied rewrites84.0%

      \[\leadsto \cos \left(\tan^{-1} \left(\frac{\left(\left(2 \cdot \left(\pi + \frac{\cos \pi \cdot 0.5 - 0.5}{\cos \pi \cdot -0.5 - 0.5} \cdot \pi\right)\right) \cdot z2 - \tan \left(\pi \cdot -0.5\right)\right) \cdot z0}{z1}\right) \cdot 2\right) \]
    7. Applied rewrites84.0%

      \[\leadsto \cos \left(\tan^{-1} \left(\frac{\left(\left(\pi - \frac{\pi}{0}\right) \cdot \left(z2 + z2\right) - \tan \color{blue}{\left(\pi \cdot -0.5\right)}\right) \cdot z0}{z1}\right) \cdot 2\right) \]

    if -2.8e21 < z2 < 2e7

    1. Initial program 67.3%

      \[\cos \left(\tan^{-1} \left(\tan \left(\left(\left(z2 + z2\right) - -0.5\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
    2. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\tan \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right)} \cdot 2\right) \]
      2. lift-tan.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \left(\color{blue}{\tan \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)} \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
      3. tan-quotN/A

        \[\leadsto \cos \left(\tan^{-1} \left(\color{blue}{\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}{\cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}} \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
      4. lift-/.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}{\cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)} \cdot \color{blue}{\frac{z0}{z1}}\right) \cdot 2\right) \]
      5. frac-timesN/A

        \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z0}{\cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z1}\right)} \cdot 2\right) \]
      6. *-commutativeN/A

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z0}{\color{blue}{z1 \cdot \cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}}\right) \cdot 2\right) \]
      7. lower-/.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z0}{z1 \cdot \cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}\right)} \cdot 2\right) \]
    3. Applied rewrites76.5%

      \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\cos \left(\pi \cdot \left(z2 + z2\right)\right) \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right)} \cdot 2\right) \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 3: 99.4% accurate, 0.9× speedup?

\[\begin{array}{l} t_0 := \cos \left(\tan^{-1} \left(\frac{\left(\left(\pi - \frac{\pi}{0}\right) \cdot \left(z2 + z2\right) - \tan \left(\pi \cdot -0.5\right)\right) \cdot z0}{z1}\right) \cdot 2\right)\\ \mathbf{if}\;z2 \leq -2.8 \cdot 10^{+21}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;z2 \leq 20000000:\\ \;\;\;\;\cos \left(\tan^{-1} \left(\frac{z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \]
(FPCore (z2 z0 z1)
  :precision binary64
  (let* ((t_0
        (cos
         (*
          (atan
           (/
            (*
             (- (* (- PI (/ PI 0.0)) (+ z2 z2)) (tan (* PI -0.5)))
             z0)
            z1))
          2.0))))
  (if (<= z2 -2.8e+21)
    t_0
    (if (<= z2 20000000.0)
      (cos (* (atan (/ z0 (* (- (sin (* PI (+ z2 z2)))) z1))) 2.0))
      t_0))))
double code(double z2, double z0, double z1) {
	double t_0 = cos((atan((((((((double) M_PI) - (((double) M_PI) / 0.0)) * (z2 + z2)) - tan((((double) M_PI) * -0.5))) * z0) / z1)) * 2.0));
	double tmp;
	if (z2 <= -2.8e+21) {
		tmp = t_0;
	} else if (z2 <= 20000000.0) {
		tmp = cos((atan((z0 / (-sin((((double) M_PI) * (z2 + z2))) * z1))) * 2.0));
	} else {
		tmp = t_0;
	}
	return tmp;
}
public static double code(double z2, double z0, double z1) {
	double t_0 = Math.cos((Math.atan((((((Math.PI - (Math.PI / 0.0)) * (z2 + z2)) - Math.tan((Math.PI * -0.5))) * z0) / z1)) * 2.0));
	double tmp;
	if (z2 <= -2.8e+21) {
		tmp = t_0;
	} else if (z2 <= 20000000.0) {
		tmp = Math.cos((Math.atan((z0 / (-Math.sin((Math.PI * (z2 + z2))) * z1))) * 2.0));
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(z2, z0, z1):
	t_0 = math.cos((math.atan((((((math.pi - (math.pi / 0.0)) * (z2 + z2)) - math.tan((math.pi * -0.5))) * z0) / z1)) * 2.0))
	tmp = 0
	if z2 <= -2.8e+21:
		tmp = t_0
	elif z2 <= 20000000.0:
		tmp = math.cos((math.atan((z0 / (-math.sin((math.pi * (z2 + z2))) * z1))) * 2.0))
	else:
		tmp = t_0
	return tmp
function code(z2, z0, z1)
	t_0 = cos(Float64(atan(Float64(Float64(Float64(Float64(Float64(pi - Float64(pi / 0.0)) * Float64(z2 + z2)) - tan(Float64(pi * -0.5))) * z0) / z1)) * 2.0))
	tmp = 0.0
	if (z2 <= -2.8e+21)
		tmp = t_0;
	elseif (z2 <= 20000000.0)
		tmp = cos(Float64(atan(Float64(z0 / Float64(Float64(-sin(Float64(pi * Float64(z2 + z2)))) * z1))) * 2.0));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(z2, z0, z1)
	t_0 = cos((atan((((((pi - (pi / 0.0)) * (z2 + z2)) - tan((pi * -0.5))) * z0) / z1)) * 2.0));
	tmp = 0.0;
	if (z2 <= -2.8e+21)
		tmp = t_0;
	elseif (z2 <= 20000000.0)
		tmp = cos((atan((z0 / (-sin((pi * (z2 + z2))) * z1))) * 2.0));
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[z2_, z0_, z1_] := Block[{t$95$0 = N[Cos[N[(N[ArcTan[N[(N[(N[(N[(N[(Pi - N[(Pi / 0.0), $MachinePrecision]), $MachinePrecision] * N[(z2 + z2), $MachinePrecision]), $MachinePrecision] - N[Tan[N[(Pi * -0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * z0), $MachinePrecision] / z1), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[z2, -2.8e+21], t$95$0, If[LessEqual[z2, 20000000.0], N[Cos[N[(N[ArcTan[N[(z0 / N[((-N[Sin[N[(Pi * N[(z2 + z2), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]) * z1), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision], t$95$0]]]
\begin{array}{l}
t_0 := \cos \left(\tan^{-1} \left(\frac{\left(\left(\pi - \frac{\pi}{0}\right) \cdot \left(z2 + z2\right) - \tan \left(\pi \cdot -0.5\right)\right) \cdot z0}{z1}\right) \cdot 2\right)\\
\mathbf{if}\;z2 \leq -2.8 \cdot 10^{+21}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;z2 \leq 20000000:\\
\;\;\;\;\cos \left(\tan^{-1} \left(\frac{z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right)\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z2 < -2.8e21 or 2e7 < z2

    1. Initial program 67.3%

      \[\cos \left(\tan^{-1} \left(\tan \left(\left(\left(z2 + z2\right) - -0.5\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
    2. Taylor expanded in z2 around 0

      \[\leadsto \cos \left(\tan^{-1} \left(\color{blue}{\left(z2 \cdot \left(2 \cdot \pi - -2 \cdot \frac{\pi \cdot {\sin \left(\frac{1}{2} \cdot \pi\right)}^{2}}{{\cos \left(\frac{1}{2} \cdot \pi\right)}^{2}}\right) + \frac{\sin \left(\frac{1}{2} \cdot \pi\right)}{\cos \left(\frac{1}{2} \cdot \pi\right)}\right)} \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
    3. Step-by-step derivation
      1. lower-+.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \left(\left(z2 \cdot \left(2 \cdot \mathsf{PI}\left(\right) - -2 \cdot \frac{\mathsf{PI}\left(\right) \cdot {\sin \left(\frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)}^{2}}{{\cos \left(\frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)}^{2}}\right) + \color{blue}{\frac{\sin \left(\frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)}{\cos \left(\frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)}}\right) \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
    4. Applied rewrites78.7%

      \[\leadsto \cos \left(\tan^{-1} \left(\color{blue}{\left(z2 \cdot \left(2 \cdot \pi - -2 \cdot \frac{\pi \cdot {\sin \left(0.5 \cdot \pi\right)}^{2}}{{\cos \left(0.5 \cdot \pi\right)}^{2}}\right) + \frac{\sin \left(0.5 \cdot \pi\right)}{\cos \left(0.5 \cdot \pi\right)}\right)} \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
    5. Applied rewrites79.2%

      \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\left(\left(2 \cdot \left(\pi + \left(\tan \left(0.5 \cdot \pi\right) \cdot \tan \left(0.5 \cdot \pi\right)\right) \cdot \pi\right)\right) \cdot z2 - \tan \left(\pi \cdot -0.5\right)\right) \cdot z0}{z1}\right)} \cdot 2\right) \]
    6. Applied rewrites84.0%

      \[\leadsto \cos \left(\tan^{-1} \left(\frac{\left(\left(2 \cdot \left(\pi + \frac{\cos \pi \cdot 0.5 - 0.5}{\cos \pi \cdot -0.5 - 0.5} \cdot \pi\right)\right) \cdot z2 - \tan \left(\pi \cdot -0.5\right)\right) \cdot z0}{z1}\right) \cdot 2\right) \]
    7. Applied rewrites84.0%

      \[\leadsto \cos \left(\tan^{-1} \left(\frac{\left(\left(\pi - \frac{\pi}{0}\right) \cdot \left(z2 + z2\right) - \tan \color{blue}{\left(\pi \cdot -0.5\right)}\right) \cdot z0}{z1}\right) \cdot 2\right) \]

    if -2.8e21 < z2 < 2e7

    1. Initial program 67.3%

      \[\cos \left(\tan^{-1} \left(\tan \left(\left(\left(z2 + z2\right) - -0.5\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
    2. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\tan \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right)} \cdot 2\right) \]
      2. lift-tan.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \left(\color{blue}{\tan \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)} \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
      3. tan-quotN/A

        \[\leadsto \cos \left(\tan^{-1} \left(\color{blue}{\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}{\cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}} \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
      4. lift-/.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}{\cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)} \cdot \color{blue}{\frac{z0}{z1}}\right) \cdot 2\right) \]
      5. frac-timesN/A

        \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z0}{\cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z1}\right)} \cdot 2\right) \]
      6. *-commutativeN/A

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z0}{\color{blue}{z1 \cdot \cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}}\right) \cdot 2\right) \]
      7. lower-/.f64N/A

        \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z0}{z1 \cdot \cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}\right)} \cdot 2\right) \]
    3. Applied rewrites76.5%

      \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\cos \left(\pi \cdot \left(z2 + z2\right)\right) \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right)} \cdot 2\right) \]
    4. Taylor expanded in z2 around 0

      \[\leadsto \cos \left(\tan^{-1} \left(\frac{\color{blue}{z0}}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right) \]
    5. Step-by-step derivation
      1. Applied rewrites76.5%

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\color{blue}{z0}}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right) \]
    6. Recombined 2 regimes into one program.
    7. Add Preprocessing

    Alternative 4: 77.7% accurate, 0.7× speedup?

    \[\begin{array}{l} \mathbf{if}\;\tan \left(\left(\left(z2 + z2\right) - -0.5\right) \cdot \pi\right) \leq 100:\\ \;\;\;\;\cos \left(\tan^{-1} \left(\tan \left(0.5 \cdot \pi\right) \cdot \frac{z0}{z1}\right) \cdot 2\right)\\ \mathbf{else}:\\ \;\;\;\;\cos \left(\tan^{-1} \left(-0.5 \cdot \frac{z0}{z1 \cdot \left(z2 \cdot \pi\right)}\right) \cdot 2\right)\\ \end{array} \]
    (FPCore (z2 z0 z1)
      :precision binary64
      (if (<= (tan (* (- (+ z2 z2) -0.5) PI)) 100.0)
      (cos (* (atan (* (tan (* 0.5 PI)) (/ z0 z1))) 2.0))
      (cos (* (atan (* -0.5 (/ z0 (* z1 (* z2 PI))))) 2.0))))
    double code(double z2, double z0, double z1) {
    	double tmp;
    	if (tan((((z2 + z2) - -0.5) * ((double) M_PI))) <= 100.0) {
    		tmp = cos((atan((tan((0.5 * ((double) M_PI))) * (z0 / z1))) * 2.0));
    	} else {
    		tmp = cos((atan((-0.5 * (z0 / (z1 * (z2 * ((double) M_PI)))))) * 2.0));
    	}
    	return tmp;
    }
    
    public static double code(double z2, double z0, double z1) {
    	double tmp;
    	if (Math.tan((((z2 + z2) - -0.5) * Math.PI)) <= 100.0) {
    		tmp = Math.cos((Math.atan((Math.tan((0.5 * Math.PI)) * (z0 / z1))) * 2.0));
    	} else {
    		tmp = Math.cos((Math.atan((-0.5 * (z0 / (z1 * (z2 * Math.PI))))) * 2.0));
    	}
    	return tmp;
    }
    
    def code(z2, z0, z1):
    	tmp = 0
    	if math.tan((((z2 + z2) - -0.5) * math.pi)) <= 100.0:
    		tmp = math.cos((math.atan((math.tan((0.5 * math.pi)) * (z0 / z1))) * 2.0))
    	else:
    		tmp = math.cos((math.atan((-0.5 * (z0 / (z1 * (z2 * math.pi))))) * 2.0))
    	return tmp
    
    function code(z2, z0, z1)
    	tmp = 0.0
    	if (tan(Float64(Float64(Float64(z2 + z2) - -0.5) * pi)) <= 100.0)
    		tmp = cos(Float64(atan(Float64(tan(Float64(0.5 * pi)) * Float64(z0 / z1))) * 2.0));
    	else
    		tmp = cos(Float64(atan(Float64(-0.5 * Float64(z0 / Float64(z1 * Float64(z2 * pi))))) * 2.0));
    	end
    	return tmp
    end
    
    function tmp_2 = code(z2, z0, z1)
    	tmp = 0.0;
    	if (tan((((z2 + z2) - -0.5) * pi)) <= 100.0)
    		tmp = cos((atan((tan((0.5 * pi)) * (z0 / z1))) * 2.0));
    	else
    		tmp = cos((atan((-0.5 * (z0 / (z1 * (z2 * pi))))) * 2.0));
    	end
    	tmp_2 = tmp;
    end
    
    code[z2_, z0_, z1_] := If[LessEqual[N[Tan[N[(N[(N[(z2 + z2), $MachinePrecision] - -0.5), $MachinePrecision] * Pi), $MachinePrecision]], $MachinePrecision], 100.0], N[Cos[N[(N[ArcTan[N[(N[Tan[N[(0.5 * Pi), $MachinePrecision]], $MachinePrecision] * N[(z0 / z1), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision], N[Cos[N[(N[ArcTan[N[(-0.5 * N[(z0 / N[(z1 * N[(z2 * Pi), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision]]
    
    \begin{array}{l}
    \mathbf{if}\;\tan \left(\left(\left(z2 + z2\right) - -0.5\right) \cdot \pi\right) \leq 100:\\
    \;\;\;\;\cos \left(\tan^{-1} \left(\tan \left(0.5 \cdot \pi\right) \cdot \frac{z0}{z1}\right) \cdot 2\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\cos \left(\tan^{-1} \left(-0.5 \cdot \frac{z0}{z1 \cdot \left(z2 \cdot \pi\right)}\right) \cdot 2\right)\\
    
    
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (tan.f64 (*.f64 (-.f64 (+.f64 z2 z2) #s(literal -1/2 binary64)) (PI.f64))) < 100

      1. Initial program 67.3%

        \[\cos \left(\tan^{-1} \left(\tan \left(\left(\left(z2 + z2\right) - -0.5\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
      2. Taylor expanded in z2 around 0

        \[\leadsto \cos \left(\tan^{-1} \left(\tan \left(\color{blue}{\frac{1}{2}} \cdot \pi\right) \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
      3. Step-by-step derivation
        1. Applied rewrites68.6%

          \[\leadsto \cos \left(\tan^{-1} \left(\tan \left(\color{blue}{0.5} \cdot \pi\right) \cdot \frac{z0}{z1}\right) \cdot 2\right) \]

        if 100 < (tan.f64 (*.f64 (-.f64 (+.f64 z2 z2) #s(literal -1/2 binary64)) (PI.f64)))

        1. Initial program 67.3%

          \[\cos \left(\tan^{-1} \left(\tan \left(\left(\left(z2 + z2\right) - -0.5\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
        2. Step-by-step derivation
          1. lift-*.f64N/A

            \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\tan \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right)} \cdot 2\right) \]
          2. lift-tan.f64N/A

            \[\leadsto \cos \left(\tan^{-1} \left(\color{blue}{\tan \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)} \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
          3. tan-quotN/A

            \[\leadsto \cos \left(\tan^{-1} \left(\color{blue}{\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}{\cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}} \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
          4. lift-/.f64N/A

            \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}{\cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)} \cdot \color{blue}{\frac{z0}{z1}}\right) \cdot 2\right) \]
          5. frac-timesN/A

            \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z0}{\cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z1}\right)} \cdot 2\right) \]
          6. *-commutativeN/A

            \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z0}{\color{blue}{z1 \cdot \cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}}\right) \cdot 2\right) \]
          7. lower-/.f64N/A

            \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z0}{z1 \cdot \cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}\right)} \cdot 2\right) \]
        3. Applied rewrites76.5%

          \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\cos \left(\pi \cdot \left(z2 + z2\right)\right) \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right)} \cdot 2\right) \]
        4. Taylor expanded in z2 around 0

          \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{-1}{2} \cdot \frac{z0}{z1 \cdot \left(z2 \cdot \pi\right)}\right)} \cdot 2\right) \]
        5. Step-by-step derivation
          1. lower-*.f64N/A

            \[\leadsto \cos \left(\tan^{-1} \left(\frac{-1}{2} \cdot \color{blue}{\frac{z0}{z1 \cdot \left(z2 \cdot \mathsf{PI}\left(\right)\right)}}\right) \cdot 2\right) \]
          2. lower-/.f64N/A

            \[\leadsto \cos \left(\tan^{-1} \left(\frac{-1}{2} \cdot \frac{z0}{\color{blue}{z1 \cdot \left(z2 \cdot \mathsf{PI}\left(\right)\right)}}\right) \cdot 2\right) \]
          3. lower-*.f64N/A

            \[\leadsto \cos \left(\tan^{-1} \left(\frac{-1}{2} \cdot \frac{z0}{z1 \cdot \color{blue}{\left(z2 \cdot \mathsf{PI}\left(\right)\right)}}\right) \cdot 2\right) \]
          4. lower-*.f64N/A

            \[\leadsto \cos \left(\tan^{-1} \left(\frac{-1}{2} \cdot \frac{z0}{z1 \cdot \left(z2 \cdot \color{blue}{\mathsf{PI}\left(\right)}\right)}\right) \cdot 2\right) \]
          5. lower-PI.f6466.2%

            \[\leadsto \cos \left(\tan^{-1} \left(-0.5 \cdot \frac{z0}{z1 \cdot \left(z2 \cdot \pi\right)}\right) \cdot 2\right) \]
        6. Applied rewrites66.2%

          \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(-0.5 \cdot \frac{z0}{z1 \cdot \left(z2 \cdot \pi\right)}\right)} \cdot 2\right) \]
      4. Recombined 2 regimes into one program.
      5. Add Preprocessing

      Alternative 5: 76.5% accurate, 1.0× speedup?

      \[\cos \left(\tan^{-1} \left(\frac{z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right) \]
      (FPCore (z2 z0 z1)
        :precision binary64
        (cos (* (atan (/ z0 (* (- (sin (* PI (+ z2 z2)))) z1))) 2.0)))
      double code(double z2, double z0, double z1) {
      	return cos((atan((z0 / (-sin((((double) M_PI) * (z2 + z2))) * z1))) * 2.0));
      }
      
      public static double code(double z2, double z0, double z1) {
      	return Math.cos((Math.atan((z0 / (-Math.sin((Math.PI * (z2 + z2))) * z1))) * 2.0));
      }
      
      def code(z2, z0, z1):
      	return math.cos((math.atan((z0 / (-math.sin((math.pi * (z2 + z2))) * z1))) * 2.0))
      
      function code(z2, z0, z1)
      	return cos(Float64(atan(Float64(z0 / Float64(Float64(-sin(Float64(pi * Float64(z2 + z2)))) * z1))) * 2.0))
      end
      
      function tmp = code(z2, z0, z1)
      	tmp = cos((atan((z0 / (-sin((pi * (z2 + z2))) * z1))) * 2.0));
      end
      
      code[z2_, z0_, z1_] := N[Cos[N[(N[ArcTan[N[(z0 / N[((-N[Sin[N[(Pi * N[(z2 + z2), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]) * z1), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision]
      
      \cos \left(\tan^{-1} \left(\frac{z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right)
      
      Derivation
      1. Initial program 67.3%

        \[\cos \left(\tan^{-1} \left(\tan \left(\left(\left(z2 + z2\right) - -0.5\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
      2. Step-by-step derivation
        1. lift-*.f64N/A

          \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\tan \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right)} \cdot 2\right) \]
        2. lift-tan.f64N/A

          \[\leadsto \cos \left(\tan^{-1} \left(\color{blue}{\tan \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)} \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
        3. tan-quotN/A

          \[\leadsto \cos \left(\tan^{-1} \left(\color{blue}{\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}{\cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}} \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
        4. lift-/.f64N/A

          \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}{\cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)} \cdot \color{blue}{\frac{z0}{z1}}\right) \cdot 2\right) \]
        5. frac-timesN/A

          \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z0}{\cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z1}\right)} \cdot 2\right) \]
        6. *-commutativeN/A

          \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z0}{\color{blue}{z1 \cdot \cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}}\right) \cdot 2\right) \]
        7. lower-/.f64N/A

          \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z0}{z1 \cdot \cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}\right)} \cdot 2\right) \]
      3. Applied rewrites76.5%

        \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\cos \left(\pi \cdot \left(z2 + z2\right)\right) \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right)} \cdot 2\right) \]
      4. Taylor expanded in z2 around 0

        \[\leadsto \cos \left(\tan^{-1} \left(\frac{\color{blue}{z0}}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right) \]
      5. Step-by-step derivation
        1. Applied rewrites76.5%

          \[\leadsto \cos \left(\tan^{-1} \left(\frac{\color{blue}{z0}}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right) \cdot 2\right) \]
        2. Add Preprocessing

        Alternative 6: 66.2% accurate, 1.4× speedup?

        \[\cos \left(\tan^{-1} \left(-0.5 \cdot \frac{z0}{z1 \cdot \left(z2 \cdot \pi\right)}\right) \cdot 2\right) \]
        (FPCore (z2 z0 z1)
          :precision binary64
          (cos (* (atan (* -0.5 (/ z0 (* z1 (* z2 PI))))) 2.0)))
        double code(double z2, double z0, double z1) {
        	return cos((atan((-0.5 * (z0 / (z1 * (z2 * ((double) M_PI)))))) * 2.0));
        }
        
        public static double code(double z2, double z0, double z1) {
        	return Math.cos((Math.atan((-0.5 * (z0 / (z1 * (z2 * Math.PI))))) * 2.0));
        }
        
        def code(z2, z0, z1):
        	return math.cos((math.atan((-0.5 * (z0 / (z1 * (z2 * math.pi))))) * 2.0))
        
        function code(z2, z0, z1)
        	return cos(Float64(atan(Float64(-0.5 * Float64(z0 / Float64(z1 * Float64(z2 * pi))))) * 2.0))
        end
        
        function tmp = code(z2, z0, z1)
        	tmp = cos((atan((-0.5 * (z0 / (z1 * (z2 * pi))))) * 2.0));
        end
        
        code[z2_, z0_, z1_] := N[Cos[N[(N[ArcTan[N[(-0.5 * N[(z0 / N[(z1 * N[(z2 * Pi), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision]
        
        \cos \left(\tan^{-1} \left(-0.5 \cdot \frac{z0}{z1 \cdot \left(z2 \cdot \pi\right)}\right) \cdot 2\right)
        
        Derivation
        1. Initial program 67.3%

          \[\cos \left(\tan^{-1} \left(\tan \left(\left(\left(z2 + z2\right) - -0.5\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
        2. Step-by-step derivation
          1. lift-*.f64N/A

            \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\tan \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot \frac{z0}{z1}\right)} \cdot 2\right) \]
          2. lift-tan.f64N/A

            \[\leadsto \cos \left(\tan^{-1} \left(\color{blue}{\tan \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)} \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
          3. tan-quotN/A

            \[\leadsto \cos \left(\tan^{-1} \left(\color{blue}{\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}{\cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}} \cdot \frac{z0}{z1}\right) \cdot 2\right) \]
          4. lift-/.f64N/A

            \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}{\cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)} \cdot \color{blue}{\frac{z0}{z1}}\right) \cdot 2\right) \]
          5. frac-timesN/A

            \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z0}{\cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z1}\right)} \cdot 2\right) \]
          6. *-commutativeN/A

            \[\leadsto \cos \left(\tan^{-1} \left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z0}{\color{blue}{z1 \cdot \cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}}\right) \cdot 2\right) \]
          7. lower-/.f64N/A

            \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\sin \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right) \cdot z0}{z1 \cdot \cos \left(\left(\left(z2 + z2\right) - \frac{-1}{2}\right) \cdot \pi\right)}\right)} \cdot 2\right) \]
        3. Applied rewrites76.5%

          \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{\cos \left(\pi \cdot \left(z2 + z2\right)\right) \cdot z0}{\left(-\sin \left(\pi \cdot \left(z2 + z2\right)\right)\right) \cdot z1}\right)} \cdot 2\right) \]
        4. Taylor expanded in z2 around 0

          \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(\frac{-1}{2} \cdot \frac{z0}{z1 \cdot \left(z2 \cdot \pi\right)}\right)} \cdot 2\right) \]
        5. Step-by-step derivation
          1. lower-*.f64N/A

            \[\leadsto \cos \left(\tan^{-1} \left(\frac{-1}{2} \cdot \color{blue}{\frac{z0}{z1 \cdot \left(z2 \cdot \mathsf{PI}\left(\right)\right)}}\right) \cdot 2\right) \]
          2. lower-/.f64N/A

            \[\leadsto \cos \left(\tan^{-1} \left(\frac{-1}{2} \cdot \frac{z0}{\color{blue}{z1 \cdot \left(z2 \cdot \mathsf{PI}\left(\right)\right)}}\right) \cdot 2\right) \]
          3. lower-*.f64N/A

            \[\leadsto \cos \left(\tan^{-1} \left(\frac{-1}{2} \cdot \frac{z0}{z1 \cdot \color{blue}{\left(z2 \cdot \mathsf{PI}\left(\right)\right)}}\right) \cdot 2\right) \]
          4. lower-*.f64N/A

            \[\leadsto \cos \left(\tan^{-1} \left(\frac{-1}{2} \cdot \frac{z0}{z1 \cdot \left(z2 \cdot \color{blue}{\mathsf{PI}\left(\right)}\right)}\right) \cdot 2\right) \]
          5. lower-PI.f6466.2%

            \[\leadsto \cos \left(\tan^{-1} \left(-0.5 \cdot \frac{z0}{z1 \cdot \left(z2 \cdot \pi\right)}\right) \cdot 2\right) \]
        6. Applied rewrites66.2%

          \[\leadsto \cos \left(\tan^{-1} \color{blue}{\left(-0.5 \cdot \frac{z0}{z1 \cdot \left(z2 \cdot \pi\right)}\right)} \cdot 2\right) \]
        7. Add Preprocessing

        Reproduce

        ?
        herbie shell --seed 2025250 
        (FPCore (z2 z0 z1)
          :name "(cos (* (atan (* (tan (* (- (+ z2 z2) -1/2) PI)) (/ z0 z1))) 2))"
          :precision binary64
          (cos (* (atan (* (tan (* (- (+ z2 z2) -0.5) PI)) (/ z0 z1))) 2.0)))