Migdal et al, Equation (64)

Percentage Accurate: 99.6% → 99.6%
Time: 8.4s
Alternatives: 13
Speedup: 2.0×

Specification

?
\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{\cos th}{\sqrt{2}}\\ t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right) \end{array} \end{array} \]
(FPCore (a1 a2 th)
 :precision binary64
 (let* ((t_1 (/ (cos th) (sqrt 2.0))))
   (+ (* t_1 (* a1 a1)) (* t_1 (* a2 a2)))))
double code(double a1, double a2, double th) {
	double t_1 = cos(th) / sqrt(2.0);
	return (t_1 * (a1 * a1)) + (t_1 * (a2 * a2));
}
real(8) function code(a1, a2, th)
    real(8), intent (in) :: a1
    real(8), intent (in) :: a2
    real(8), intent (in) :: th
    real(8) :: t_1
    t_1 = cos(th) / sqrt(2.0d0)
    code = (t_1 * (a1 * a1)) + (t_1 * (a2 * a2))
end function
public static double code(double a1, double a2, double th) {
	double t_1 = Math.cos(th) / Math.sqrt(2.0);
	return (t_1 * (a1 * a1)) + (t_1 * (a2 * a2));
}
def code(a1, a2, th):
	t_1 = math.cos(th) / math.sqrt(2.0)
	return (t_1 * (a1 * a1)) + (t_1 * (a2 * a2))
function code(a1, a2, th)
	t_1 = Float64(cos(th) / sqrt(2.0))
	return Float64(Float64(t_1 * Float64(a1 * a1)) + Float64(t_1 * Float64(a2 * a2)))
end
function tmp = code(a1, a2, th)
	t_1 = cos(th) / sqrt(2.0);
	tmp = (t_1 * (a1 * a1)) + (t_1 * (a2 * a2));
end
code[a1_, a2_, th_] := Block[{t$95$1 = N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]}, N[(N[(t$95$1 * N[(a1 * a1), $MachinePrecision]), $MachinePrecision] + N[(t$95$1 * N[(a2 * a2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{\cos th}{\sqrt{2}}\\
t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right)
\end{array}
\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 13 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 99.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{\cos th}{\sqrt{2}}\\ t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right) \end{array} \end{array} \]
(FPCore (a1 a2 th)
 :precision binary64
 (let* ((t_1 (/ (cos th) (sqrt 2.0))))
   (+ (* t_1 (* a1 a1)) (* t_1 (* a2 a2)))))
double code(double a1, double a2, double th) {
	double t_1 = cos(th) / sqrt(2.0);
	return (t_1 * (a1 * a1)) + (t_1 * (a2 * a2));
}
real(8) function code(a1, a2, th)
    real(8), intent (in) :: a1
    real(8), intent (in) :: a2
    real(8), intent (in) :: th
    real(8) :: t_1
    t_1 = cos(th) / sqrt(2.0d0)
    code = (t_1 * (a1 * a1)) + (t_1 * (a2 * a2))
end function
public static double code(double a1, double a2, double th) {
	double t_1 = Math.cos(th) / Math.sqrt(2.0);
	return (t_1 * (a1 * a1)) + (t_1 * (a2 * a2));
}
def code(a1, a2, th):
	t_1 = math.cos(th) / math.sqrt(2.0)
	return (t_1 * (a1 * a1)) + (t_1 * (a2 * a2))
function code(a1, a2, th)
	t_1 = Float64(cos(th) / sqrt(2.0))
	return Float64(Float64(t_1 * Float64(a1 * a1)) + Float64(t_1 * Float64(a2 * a2)))
end
function tmp = code(a1, a2, th)
	t_1 = cos(th) / sqrt(2.0);
	tmp = (t_1 * (a1 * a1)) + (t_1 * (a2 * a2));
end
code[a1_, a2_, th_] := Block[{t$95$1 = N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]}, N[(N[(t$95$1 * N[(a1 * a1), $MachinePrecision]), $MachinePrecision] + N[(t$95$1 * N[(a2 * a2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{\cos th}{\sqrt{2}}\\
t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right)
\end{array}
\end{array}

Alternative 1: 99.6% accurate, 1.0× speedup?

\[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \mathsf{fma}\left(\frac{a2}{\sqrt{2}} \cdot \cos th, a2, \left(\frac{a1}{\sqrt{2}} \cdot a1\right) \cdot \cos th\right) \end{array} \]
NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
(FPCore (a1 a2 th)
 :precision binary64
 (fma (* (/ a2 (sqrt 2.0)) (cos th)) a2 (* (* (/ a1 (sqrt 2.0)) a1) (cos th))))
assert(a1 < a2 && a2 < th);
double code(double a1, double a2, double th) {
	return fma(((a2 / sqrt(2.0)) * cos(th)), a2, (((a1 / sqrt(2.0)) * a1) * cos(th)));
}
a1, a2, th = sort([a1, a2, th])
function code(a1, a2, th)
	return fma(Float64(Float64(a2 / sqrt(2.0)) * cos(th)), a2, Float64(Float64(Float64(a1 / sqrt(2.0)) * a1) * cos(th)))
end
NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
code[a1_, a2_, th_] := N[(N[(N[(a2 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision] * a2 + N[(N[(N[(a1 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * a1), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
[a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
\\
\mathsf{fma}\left(\frac{a2}{\sqrt{2}} \cdot \cos th, a2, \left(\frac{a1}{\sqrt{2}} \cdot a1\right) \cdot \cos th\right)
\end{array}
Derivation
  1. Initial program 99.6%

    \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-+.f64N/A

      \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
    2. +-commutativeN/A

      \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)} \]
    3. lift-*.f64N/A

      \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) \]
    4. lift-*.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \color{blue}{\left(a2 \cdot a2\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) \]
    5. associate-*r*N/A

      \[\leadsto \color{blue}{\left(\frac{\cos th}{\sqrt{2}} \cdot a2\right) \cdot a2} + \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) \]
    6. lower-fma.f64N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\cos th}{\sqrt{2}} \cdot a2, a2, \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)\right)} \]
    7. lift-/.f64N/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot a2, a2, \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)\right) \]
    8. div-invN/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\cos th \cdot \frac{1}{\sqrt{2}}\right)} \cdot a2, a2, \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)\right) \]
    9. associate-*l*N/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{\cos th \cdot \left(\frac{1}{\sqrt{2}} \cdot a2\right)}, a2, \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)\right) \]
    10. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\frac{1}{\sqrt{2}} \cdot a2\right) \cdot \cos th}, a2, \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)\right) \]
    11. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\frac{1}{\sqrt{2}} \cdot a2\right) \cdot \cos th}, a2, \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)\right) \]
    12. associate-*l/N/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{1 \cdot a2}{\sqrt{2}}} \cdot \cos th, a2, \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)\right) \]
    13. *-lft-identityN/A

      \[\leadsto \mathsf{fma}\left(\frac{\color{blue}{a2}}{\sqrt{2}} \cdot \cos th, a2, \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)\right) \]
    14. lower-/.f6499.6

      \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{a2}{\sqrt{2}}} \cdot \cos th, a2, \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)\right) \]
    15. lift-*.f64N/A

      \[\leadsto \mathsf{fma}\left(\frac{a2}{\sqrt{2}} \cdot \cos th, a2, \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)}\right) \]
    16. lift-/.f64N/A

      \[\leadsto \mathsf{fma}\left(\frac{a2}{\sqrt{2}} \cdot \cos th, a2, \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1\right)\right) \]
    17. associate-*l/N/A

      \[\leadsto \mathsf{fma}\left(\frac{a2}{\sqrt{2}} \cdot \cos th, a2, \color{blue}{\frac{\cos th \cdot \left(a1 \cdot a1\right)}{\sqrt{2}}}\right) \]
    18. associate-/l*N/A

      \[\leadsto \mathsf{fma}\left(\frac{a2}{\sqrt{2}} \cdot \cos th, a2, \color{blue}{\cos th \cdot \frac{a1 \cdot a1}{\sqrt{2}}}\right) \]
  4. Applied rewrites99.6%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{a2}{\sqrt{2}} \cdot \cos th, a2, \left(\frac{a1}{\sqrt{2}} \cdot a1\right) \cdot \cos th\right)} \]
  5. Add Preprocessing

Alternative 2: 74.6% accurate, 0.8× speedup?

\[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \begin{array}{l} t_1 := \frac{\cos th}{\sqrt{2}}\\ \mathbf{if}\;t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right) \leq -1 \cdot 10^{-119}:\\ \;\;\;\;\mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot \left(\left(\sqrt{0.5} \cdot a2\right) \cdot a2\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{a1}{\sqrt{2}}, a1, \frac{a2}{\frac{\sqrt{2}}{a2}}\right)\\ \end{array} \end{array} \]
NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
(FPCore (a1 a2 th)
 :precision binary64
 (let* ((t_1 (/ (cos th) (sqrt 2.0))))
   (if (<= (+ (* t_1 (* a1 a1)) (* t_1 (* a2 a2))) -1e-119)
     (* (fma (* th th) -0.5 1.0) (* (* (sqrt 0.5) a2) a2))
     (fma (/ a1 (sqrt 2.0)) a1 (/ a2 (/ (sqrt 2.0) a2))))))
assert(a1 < a2 && a2 < th);
double code(double a1, double a2, double th) {
	double t_1 = cos(th) / sqrt(2.0);
	double tmp;
	if (((t_1 * (a1 * a1)) + (t_1 * (a2 * a2))) <= -1e-119) {
		tmp = fma((th * th), -0.5, 1.0) * ((sqrt(0.5) * a2) * a2);
	} else {
		tmp = fma((a1 / sqrt(2.0)), a1, (a2 / (sqrt(2.0) / a2)));
	}
	return tmp;
}
a1, a2, th = sort([a1, a2, th])
function code(a1, a2, th)
	t_1 = Float64(cos(th) / sqrt(2.0))
	tmp = 0.0
	if (Float64(Float64(t_1 * Float64(a1 * a1)) + Float64(t_1 * Float64(a2 * a2))) <= -1e-119)
		tmp = Float64(fma(Float64(th * th), -0.5, 1.0) * Float64(Float64(sqrt(0.5) * a2) * a2));
	else
		tmp = fma(Float64(a1 / sqrt(2.0)), a1, Float64(a2 / Float64(sqrt(2.0) / a2)));
	end
	return tmp
end
NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
code[a1_, a2_, th_] := Block[{t$95$1 = N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(t$95$1 * N[(a1 * a1), $MachinePrecision]), $MachinePrecision] + N[(t$95$1 * N[(a2 * a2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1e-119], N[(N[(N[(th * th), $MachinePrecision] * -0.5 + 1.0), $MachinePrecision] * N[(N[(N[Sqrt[0.5], $MachinePrecision] * a2), $MachinePrecision] * a2), $MachinePrecision]), $MachinePrecision], N[(N[(a1 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * a1 + N[(a2 / N[(N[Sqrt[2.0], $MachinePrecision] / a2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
[a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
\\
\begin{array}{l}
t_1 := \frac{\cos th}{\sqrt{2}}\\
\mathbf{if}\;t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right) \leq -1 \cdot 10^{-119}:\\
\;\;\;\;\mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot \left(\left(\sqrt{0.5} \cdot a2\right) \cdot a2\right)\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\frac{a1}{\sqrt{2}}, a1, \frac{a2}{\frac{\sqrt{2}}{a2}}\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a1 a1)) (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a2 a2))) < -1.00000000000000001e-119

    1. Initial program 99.7%

      \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
      2. lift-*.f64N/A

        \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      3. lift-*.f64N/A

        \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
      4. distribute-lft-outN/A

        \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
      5. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
      6. clear-numN/A

        \[\leadsto \color{blue}{\frac{1}{\frac{\sqrt{2}}{\cos th}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
      7. associate-/r/N/A

        \[\leadsto \color{blue}{\left(\frac{1}{\sqrt{2}} \cdot \cos th\right)} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
      8. associate-*l*N/A

        \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
      9. lower-*.f64N/A

        \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
      10. lift-sqrt.f64N/A

        \[\leadsto \frac{1}{\color{blue}{\sqrt{2}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
      11. pow1/2N/A

        \[\leadsto \frac{1}{\color{blue}{{2}^{\frac{1}{2}}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
      12. pow-flipN/A

        \[\leadsto \color{blue}{{2}^{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
      13. lower-pow.f64N/A

        \[\leadsto \color{blue}{{2}^{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
      14. metadata-evalN/A

        \[\leadsto {2}^{\color{blue}{\frac{-1}{2}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
      15. *-commutativeN/A

        \[\leadsto {2}^{\frac{-1}{2}} \cdot \color{blue}{\left(\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th\right)} \]
      16. lower-*.f64N/A

        \[\leadsto {2}^{\frac{-1}{2}} \cdot \color{blue}{\left(\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th\right)} \]
      17. +-commutativeN/A

        \[\leadsto {2}^{\frac{-1}{2}} \cdot \left(\color{blue}{\left(a2 \cdot a2 + a1 \cdot a1\right)} \cdot \cos th\right) \]
      18. lift-*.f64N/A

        \[\leadsto {2}^{\frac{-1}{2}} \cdot \left(\left(\color{blue}{a2 \cdot a2} + a1 \cdot a1\right) \cdot \cos th\right) \]
      19. lower-fma.f6499.7

        \[\leadsto {2}^{-0.5} \cdot \left(\color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)} \cdot \cos th\right) \]
    4. Applied rewrites99.7%

      \[\leadsto \color{blue}{{2}^{-0.5} \cdot \left(\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \cos th\right)} \]
    5. Taylor expanded in a1 around 0

      \[\leadsto \color{blue}{{a2}^{2} \cdot \left(\cos th \cdot \sqrt{\frac{1}{2}}\right)} \]
    6. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \color{blue}{\left(\cos th \cdot \sqrt{\frac{1}{2}}\right) \cdot {a2}^{2}} \]
      2. lower-*.f64N/A

        \[\leadsto \color{blue}{\left(\cos th \cdot \sqrt{\frac{1}{2}}\right) \cdot {a2}^{2}} \]
      3. *-commutativeN/A

        \[\leadsto \color{blue}{\left(\sqrt{\frac{1}{2}} \cdot \cos th\right)} \cdot {a2}^{2} \]
      4. lower-*.f64N/A

        \[\leadsto \color{blue}{\left(\sqrt{\frac{1}{2}} \cdot \cos th\right)} \cdot {a2}^{2} \]
      5. lower-sqrt.f64N/A

        \[\leadsto \left(\color{blue}{\sqrt{\frac{1}{2}}} \cdot \cos th\right) \cdot {a2}^{2} \]
      6. lower-cos.f64N/A

        \[\leadsto \left(\sqrt{\frac{1}{2}} \cdot \color{blue}{\cos th}\right) \cdot {a2}^{2} \]
      7. unpow2N/A

        \[\leadsto \left(\sqrt{\frac{1}{2}} \cdot \cos th\right) \cdot \color{blue}{\left(a2 \cdot a2\right)} \]
      8. lower-*.f6444.8

        \[\leadsto \left(\sqrt{0.5} \cdot \cos th\right) \cdot \color{blue}{\left(a2 \cdot a2\right)} \]
    7. Applied rewrites44.8%

      \[\leadsto \color{blue}{\left(\sqrt{0.5} \cdot \cos th\right) \cdot \left(a2 \cdot a2\right)} \]
    8. Taylor expanded in th around 0

      \[\leadsto \frac{-1}{2} \cdot \left({a2}^{2} \cdot \left({th}^{2} \cdot \sqrt{\frac{1}{2}}\right)\right) + \color{blue}{{a2}^{2} \cdot \sqrt{\frac{1}{2}}} \]
    9. Step-by-step derivation
      1. Applied rewrites41.0%

        \[\leadsto \mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot \color{blue}{\left(\left(\sqrt{0.5} \cdot a2\right) \cdot a2\right)} \]

      if -1.00000000000000001e-119 < (+.f64 (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a1 a1)) (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a2 a2)))

      1. Initial program 99.5%

        \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      2. Add Preprocessing
      3. Taylor expanded in th around 0

        \[\leadsto \color{blue}{\frac{{a1}^{2}}{\sqrt{2}} + \frac{{a2}^{2}}{\sqrt{2}}} \]
      4. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \color{blue}{\frac{{a2}^{2}}{\sqrt{2}} + \frac{{a1}^{2}}{\sqrt{2}}} \]
        2. unpow2N/A

          \[\leadsto \frac{\color{blue}{a2 \cdot a2}}{\sqrt{2}} + \frac{{a1}^{2}}{\sqrt{2}} \]
        3. associate-*l/N/A

          \[\leadsto \color{blue}{\frac{a2}{\sqrt{2}} \cdot a2} + \frac{{a1}^{2}}{\sqrt{2}} \]
        4. lower-fma.f64N/A

          \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{a2}{\sqrt{2}}, a2, \frac{{a1}^{2}}{\sqrt{2}}\right)} \]
        5. lower-/.f64N/A

          \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{a2}{\sqrt{2}}}, a2, \frac{{a1}^{2}}{\sqrt{2}}\right) \]
        6. lower-sqrt.f64N/A

          \[\leadsto \mathsf{fma}\left(\frac{a2}{\color{blue}{\sqrt{2}}}, a2, \frac{{a1}^{2}}{\sqrt{2}}\right) \]
        7. unpow2N/A

          \[\leadsto \mathsf{fma}\left(\frac{a2}{\sqrt{2}}, a2, \frac{\color{blue}{a1 \cdot a1}}{\sqrt{2}}\right) \]
        8. associate-*l/N/A

          \[\leadsto \mathsf{fma}\left(\frac{a2}{\sqrt{2}}, a2, \color{blue}{\frac{a1}{\sqrt{2}} \cdot a1}\right) \]
        9. lower-*.f64N/A

          \[\leadsto \mathsf{fma}\left(\frac{a2}{\sqrt{2}}, a2, \color{blue}{\frac{a1}{\sqrt{2}} \cdot a1}\right) \]
        10. lower-/.f64N/A

          \[\leadsto \mathsf{fma}\left(\frac{a2}{\sqrt{2}}, a2, \color{blue}{\frac{a1}{\sqrt{2}}} \cdot a1\right) \]
        11. lower-sqrt.f6481.9

          \[\leadsto \mathsf{fma}\left(\frac{a2}{\sqrt{2}}, a2, \frac{a1}{\color{blue}{\sqrt{2}}} \cdot a1\right) \]
      5. Applied rewrites81.9%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{a2}{\sqrt{2}}, a2, \frac{a1}{\sqrt{2}} \cdot a1\right)} \]
      6. Step-by-step derivation
        1. Applied rewrites81.9%

          \[\leadsto \mathsf{fma}\left(\frac{1}{\frac{\sqrt{2}}{a2}}, a2, \frac{a1}{\sqrt{2}} \cdot a1\right) \]
        2. Step-by-step derivation
          1. Applied rewrites81.9%

            \[\leadsto \mathsf{fma}\left(\frac{a1}{\sqrt{2}}, \color{blue}{a1}, \frac{a2}{\frac{\sqrt{2}}{a2}}\right) \]
        3. Recombined 2 regimes into one program.
        4. Add Preprocessing

        Alternative 3: 74.6% accurate, 0.8× speedup?

        \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \begin{array}{l} t_1 := \frac{\cos th}{\sqrt{2}}\\ \mathbf{if}\;t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right) \leq -1 \cdot 10^{-119}:\\ \;\;\;\;\mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot \left(\left(\sqrt{0.5} \cdot a2\right) \cdot a2\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{a2}{\sqrt{2}}, a2, \frac{a1}{\sqrt{2}} \cdot a1\right)\\ \end{array} \end{array} \]
        NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
        (FPCore (a1 a2 th)
         :precision binary64
         (let* ((t_1 (/ (cos th) (sqrt 2.0))))
           (if (<= (+ (* t_1 (* a1 a1)) (* t_1 (* a2 a2))) -1e-119)
             (* (fma (* th th) -0.5 1.0) (* (* (sqrt 0.5) a2) a2))
             (fma (/ a2 (sqrt 2.0)) a2 (* (/ a1 (sqrt 2.0)) a1)))))
        assert(a1 < a2 && a2 < th);
        double code(double a1, double a2, double th) {
        	double t_1 = cos(th) / sqrt(2.0);
        	double tmp;
        	if (((t_1 * (a1 * a1)) + (t_1 * (a2 * a2))) <= -1e-119) {
        		tmp = fma((th * th), -0.5, 1.0) * ((sqrt(0.5) * a2) * a2);
        	} else {
        		tmp = fma((a2 / sqrt(2.0)), a2, ((a1 / sqrt(2.0)) * a1));
        	}
        	return tmp;
        }
        
        a1, a2, th = sort([a1, a2, th])
        function code(a1, a2, th)
        	t_1 = Float64(cos(th) / sqrt(2.0))
        	tmp = 0.0
        	if (Float64(Float64(t_1 * Float64(a1 * a1)) + Float64(t_1 * Float64(a2 * a2))) <= -1e-119)
        		tmp = Float64(fma(Float64(th * th), -0.5, 1.0) * Float64(Float64(sqrt(0.5) * a2) * a2));
        	else
        		tmp = fma(Float64(a2 / sqrt(2.0)), a2, Float64(Float64(a1 / sqrt(2.0)) * a1));
        	end
        	return tmp
        end
        
        NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
        code[a1_, a2_, th_] := Block[{t$95$1 = N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(t$95$1 * N[(a1 * a1), $MachinePrecision]), $MachinePrecision] + N[(t$95$1 * N[(a2 * a2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1e-119], N[(N[(N[(th * th), $MachinePrecision] * -0.5 + 1.0), $MachinePrecision] * N[(N[(N[Sqrt[0.5], $MachinePrecision] * a2), $MachinePrecision] * a2), $MachinePrecision]), $MachinePrecision], N[(N[(a2 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * a2 + N[(N[(a1 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * a1), $MachinePrecision]), $MachinePrecision]]]
        
        \begin{array}{l}
        [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
        \\
        \begin{array}{l}
        t_1 := \frac{\cos th}{\sqrt{2}}\\
        \mathbf{if}\;t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right) \leq -1 \cdot 10^{-119}:\\
        \;\;\;\;\mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot \left(\left(\sqrt{0.5} \cdot a2\right) \cdot a2\right)\\
        
        \mathbf{else}:\\
        \;\;\;\;\mathsf{fma}\left(\frac{a2}{\sqrt{2}}, a2, \frac{a1}{\sqrt{2}} \cdot a1\right)\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if (+.f64 (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a1 a1)) (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a2 a2))) < -1.00000000000000001e-119

          1. Initial program 99.7%

            \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
          2. Add Preprocessing
          3. Step-by-step derivation
            1. lift-+.f64N/A

              \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
            2. lift-*.f64N/A

              \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
            3. lift-*.f64N/A

              \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
            4. distribute-lft-outN/A

              \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
            5. lift-/.f64N/A

              \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
            6. clear-numN/A

              \[\leadsto \color{blue}{\frac{1}{\frac{\sqrt{2}}{\cos th}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
            7. associate-/r/N/A

              \[\leadsto \color{blue}{\left(\frac{1}{\sqrt{2}} \cdot \cos th\right)} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
            8. associate-*l*N/A

              \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
            9. lower-*.f64N/A

              \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
            10. lift-sqrt.f64N/A

              \[\leadsto \frac{1}{\color{blue}{\sqrt{2}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
            11. pow1/2N/A

              \[\leadsto \frac{1}{\color{blue}{{2}^{\frac{1}{2}}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
            12. pow-flipN/A

              \[\leadsto \color{blue}{{2}^{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
            13. lower-pow.f64N/A

              \[\leadsto \color{blue}{{2}^{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
            14. metadata-evalN/A

              \[\leadsto {2}^{\color{blue}{\frac{-1}{2}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
            15. *-commutativeN/A

              \[\leadsto {2}^{\frac{-1}{2}} \cdot \color{blue}{\left(\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th\right)} \]
            16. lower-*.f64N/A

              \[\leadsto {2}^{\frac{-1}{2}} \cdot \color{blue}{\left(\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th\right)} \]
            17. +-commutativeN/A

              \[\leadsto {2}^{\frac{-1}{2}} \cdot \left(\color{blue}{\left(a2 \cdot a2 + a1 \cdot a1\right)} \cdot \cos th\right) \]
            18. lift-*.f64N/A

              \[\leadsto {2}^{\frac{-1}{2}} \cdot \left(\left(\color{blue}{a2 \cdot a2} + a1 \cdot a1\right) \cdot \cos th\right) \]
            19. lower-fma.f6499.7

              \[\leadsto {2}^{-0.5} \cdot \left(\color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)} \cdot \cos th\right) \]
          4. Applied rewrites99.7%

            \[\leadsto \color{blue}{{2}^{-0.5} \cdot \left(\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \cos th\right)} \]
          5. Taylor expanded in a1 around 0

            \[\leadsto \color{blue}{{a2}^{2} \cdot \left(\cos th \cdot \sqrt{\frac{1}{2}}\right)} \]
          6. Step-by-step derivation
            1. *-commutativeN/A

              \[\leadsto \color{blue}{\left(\cos th \cdot \sqrt{\frac{1}{2}}\right) \cdot {a2}^{2}} \]
            2. lower-*.f64N/A

              \[\leadsto \color{blue}{\left(\cos th \cdot \sqrt{\frac{1}{2}}\right) \cdot {a2}^{2}} \]
            3. *-commutativeN/A

              \[\leadsto \color{blue}{\left(\sqrt{\frac{1}{2}} \cdot \cos th\right)} \cdot {a2}^{2} \]
            4. lower-*.f64N/A

              \[\leadsto \color{blue}{\left(\sqrt{\frac{1}{2}} \cdot \cos th\right)} \cdot {a2}^{2} \]
            5. lower-sqrt.f64N/A

              \[\leadsto \left(\color{blue}{\sqrt{\frac{1}{2}}} \cdot \cos th\right) \cdot {a2}^{2} \]
            6. lower-cos.f64N/A

              \[\leadsto \left(\sqrt{\frac{1}{2}} \cdot \color{blue}{\cos th}\right) \cdot {a2}^{2} \]
            7. unpow2N/A

              \[\leadsto \left(\sqrt{\frac{1}{2}} \cdot \cos th\right) \cdot \color{blue}{\left(a2 \cdot a2\right)} \]
            8. lower-*.f6444.8

              \[\leadsto \left(\sqrt{0.5} \cdot \cos th\right) \cdot \color{blue}{\left(a2 \cdot a2\right)} \]
          7. Applied rewrites44.8%

            \[\leadsto \color{blue}{\left(\sqrt{0.5} \cdot \cos th\right) \cdot \left(a2 \cdot a2\right)} \]
          8. Taylor expanded in th around 0

            \[\leadsto \frac{-1}{2} \cdot \left({a2}^{2} \cdot \left({th}^{2} \cdot \sqrt{\frac{1}{2}}\right)\right) + \color{blue}{{a2}^{2} \cdot \sqrt{\frac{1}{2}}} \]
          9. Step-by-step derivation
            1. Applied rewrites41.0%

              \[\leadsto \mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot \color{blue}{\left(\left(\sqrt{0.5} \cdot a2\right) \cdot a2\right)} \]

            if -1.00000000000000001e-119 < (+.f64 (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a1 a1)) (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a2 a2)))

            1. Initial program 99.5%

              \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
            2. Add Preprocessing
            3. Taylor expanded in th around 0

              \[\leadsto \color{blue}{\frac{{a1}^{2}}{\sqrt{2}} + \frac{{a2}^{2}}{\sqrt{2}}} \]
            4. Step-by-step derivation
              1. +-commutativeN/A

                \[\leadsto \color{blue}{\frac{{a2}^{2}}{\sqrt{2}} + \frac{{a1}^{2}}{\sqrt{2}}} \]
              2. unpow2N/A

                \[\leadsto \frac{\color{blue}{a2 \cdot a2}}{\sqrt{2}} + \frac{{a1}^{2}}{\sqrt{2}} \]
              3. associate-*l/N/A

                \[\leadsto \color{blue}{\frac{a2}{\sqrt{2}} \cdot a2} + \frac{{a1}^{2}}{\sqrt{2}} \]
              4. lower-fma.f64N/A

                \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{a2}{\sqrt{2}}, a2, \frac{{a1}^{2}}{\sqrt{2}}\right)} \]
              5. lower-/.f64N/A

                \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{a2}{\sqrt{2}}}, a2, \frac{{a1}^{2}}{\sqrt{2}}\right) \]
              6. lower-sqrt.f64N/A

                \[\leadsto \mathsf{fma}\left(\frac{a2}{\color{blue}{\sqrt{2}}}, a2, \frac{{a1}^{2}}{\sqrt{2}}\right) \]
              7. unpow2N/A

                \[\leadsto \mathsf{fma}\left(\frac{a2}{\sqrt{2}}, a2, \frac{\color{blue}{a1 \cdot a1}}{\sqrt{2}}\right) \]
              8. associate-*l/N/A

                \[\leadsto \mathsf{fma}\left(\frac{a2}{\sqrt{2}}, a2, \color{blue}{\frac{a1}{\sqrt{2}} \cdot a1}\right) \]
              9. lower-*.f64N/A

                \[\leadsto \mathsf{fma}\left(\frac{a2}{\sqrt{2}}, a2, \color{blue}{\frac{a1}{\sqrt{2}} \cdot a1}\right) \]
              10. lower-/.f64N/A

                \[\leadsto \mathsf{fma}\left(\frac{a2}{\sqrt{2}}, a2, \color{blue}{\frac{a1}{\sqrt{2}}} \cdot a1\right) \]
              11. lower-sqrt.f6481.9

                \[\leadsto \mathsf{fma}\left(\frac{a2}{\sqrt{2}}, a2, \frac{a1}{\color{blue}{\sqrt{2}}} \cdot a1\right) \]
            5. Applied rewrites81.9%

              \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{a2}{\sqrt{2}}, a2, \frac{a1}{\sqrt{2}} \cdot a1\right)} \]
          10. Recombined 2 regimes into one program.
          11. Add Preprocessing

          Alternative 4: 74.6% accurate, 0.9× speedup?

          \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \begin{array}{l} t_1 := \frac{\cos th}{\sqrt{2}}\\ \mathbf{if}\;t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right) \leq -1 \cdot 10^{-119}:\\ \;\;\;\;\mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot \left(\left(\sqrt{0.5} \cdot a2\right) \cdot a2\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}}\\ \end{array} \end{array} \]
          NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
          (FPCore (a1 a2 th)
           :precision binary64
           (let* ((t_1 (/ (cos th) (sqrt 2.0))))
             (if (<= (+ (* t_1 (* a1 a1)) (* t_1 (* a2 a2))) -1e-119)
               (* (fma (* th th) -0.5 1.0) (* (* (sqrt 0.5) a2) a2))
               (/ (fma a2 a2 (* a1 a1)) (sqrt 2.0)))))
          assert(a1 < a2 && a2 < th);
          double code(double a1, double a2, double th) {
          	double t_1 = cos(th) / sqrt(2.0);
          	double tmp;
          	if (((t_1 * (a1 * a1)) + (t_1 * (a2 * a2))) <= -1e-119) {
          		tmp = fma((th * th), -0.5, 1.0) * ((sqrt(0.5) * a2) * a2);
          	} else {
          		tmp = fma(a2, a2, (a1 * a1)) / sqrt(2.0);
          	}
          	return tmp;
          }
          
          a1, a2, th = sort([a1, a2, th])
          function code(a1, a2, th)
          	t_1 = Float64(cos(th) / sqrt(2.0))
          	tmp = 0.0
          	if (Float64(Float64(t_1 * Float64(a1 * a1)) + Float64(t_1 * Float64(a2 * a2))) <= -1e-119)
          		tmp = Float64(fma(Float64(th * th), -0.5, 1.0) * Float64(Float64(sqrt(0.5) * a2) * a2));
          	else
          		tmp = Float64(fma(a2, a2, Float64(a1 * a1)) / sqrt(2.0));
          	end
          	return tmp
          end
          
          NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
          code[a1_, a2_, th_] := Block[{t$95$1 = N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(t$95$1 * N[(a1 * a1), $MachinePrecision]), $MachinePrecision] + N[(t$95$1 * N[(a2 * a2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1e-119], N[(N[(N[(th * th), $MachinePrecision] * -0.5 + 1.0), $MachinePrecision] * N[(N[(N[Sqrt[0.5], $MachinePrecision] * a2), $MachinePrecision] * a2), $MachinePrecision]), $MachinePrecision], N[(N[(a2 * a2 + N[(a1 * a1), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]]]
          
          \begin{array}{l}
          [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
          \\
          \begin{array}{l}
          t_1 := \frac{\cos th}{\sqrt{2}}\\
          \mathbf{if}\;t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right) \leq -1 \cdot 10^{-119}:\\
          \;\;\;\;\mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot \left(\left(\sqrt{0.5} \cdot a2\right) \cdot a2\right)\\
          
          \mathbf{else}:\\
          \;\;\;\;\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}}\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if (+.f64 (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a1 a1)) (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a2 a2))) < -1.00000000000000001e-119

            1. Initial program 99.7%

              \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
            2. Add Preprocessing
            3. Step-by-step derivation
              1. lift-+.f64N/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
              2. lift-*.f64N/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
              3. lift-*.f64N/A

                \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
              4. distribute-lft-outN/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
              5. lift-/.f64N/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
              6. clear-numN/A

                \[\leadsto \color{blue}{\frac{1}{\frac{\sqrt{2}}{\cos th}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
              7. associate-/r/N/A

                \[\leadsto \color{blue}{\left(\frac{1}{\sqrt{2}} \cdot \cos th\right)} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
              8. associate-*l*N/A

                \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
              9. lower-*.f64N/A

                \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
              10. lift-sqrt.f64N/A

                \[\leadsto \frac{1}{\color{blue}{\sqrt{2}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              11. pow1/2N/A

                \[\leadsto \frac{1}{\color{blue}{{2}^{\frac{1}{2}}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              12. pow-flipN/A

                \[\leadsto \color{blue}{{2}^{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              13. lower-pow.f64N/A

                \[\leadsto \color{blue}{{2}^{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              14. metadata-evalN/A

                \[\leadsto {2}^{\color{blue}{\frac{-1}{2}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              15. *-commutativeN/A

                \[\leadsto {2}^{\frac{-1}{2}} \cdot \color{blue}{\left(\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th\right)} \]
              16. lower-*.f64N/A

                \[\leadsto {2}^{\frac{-1}{2}} \cdot \color{blue}{\left(\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th\right)} \]
              17. +-commutativeN/A

                \[\leadsto {2}^{\frac{-1}{2}} \cdot \left(\color{blue}{\left(a2 \cdot a2 + a1 \cdot a1\right)} \cdot \cos th\right) \]
              18. lift-*.f64N/A

                \[\leadsto {2}^{\frac{-1}{2}} \cdot \left(\left(\color{blue}{a2 \cdot a2} + a1 \cdot a1\right) \cdot \cos th\right) \]
              19. lower-fma.f6499.7

                \[\leadsto {2}^{-0.5} \cdot \left(\color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)} \cdot \cos th\right) \]
            4. Applied rewrites99.7%

              \[\leadsto \color{blue}{{2}^{-0.5} \cdot \left(\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \cos th\right)} \]
            5. Taylor expanded in a1 around 0

              \[\leadsto \color{blue}{{a2}^{2} \cdot \left(\cos th \cdot \sqrt{\frac{1}{2}}\right)} \]
            6. Step-by-step derivation
              1. *-commutativeN/A

                \[\leadsto \color{blue}{\left(\cos th \cdot \sqrt{\frac{1}{2}}\right) \cdot {a2}^{2}} \]
              2. lower-*.f64N/A

                \[\leadsto \color{blue}{\left(\cos th \cdot \sqrt{\frac{1}{2}}\right) \cdot {a2}^{2}} \]
              3. *-commutativeN/A

                \[\leadsto \color{blue}{\left(\sqrt{\frac{1}{2}} \cdot \cos th\right)} \cdot {a2}^{2} \]
              4. lower-*.f64N/A

                \[\leadsto \color{blue}{\left(\sqrt{\frac{1}{2}} \cdot \cos th\right)} \cdot {a2}^{2} \]
              5. lower-sqrt.f64N/A

                \[\leadsto \left(\color{blue}{\sqrt{\frac{1}{2}}} \cdot \cos th\right) \cdot {a2}^{2} \]
              6. lower-cos.f64N/A

                \[\leadsto \left(\sqrt{\frac{1}{2}} \cdot \color{blue}{\cos th}\right) \cdot {a2}^{2} \]
              7. unpow2N/A

                \[\leadsto \left(\sqrt{\frac{1}{2}} \cdot \cos th\right) \cdot \color{blue}{\left(a2 \cdot a2\right)} \]
              8. lower-*.f6444.8

                \[\leadsto \left(\sqrt{0.5} \cdot \cos th\right) \cdot \color{blue}{\left(a2 \cdot a2\right)} \]
            7. Applied rewrites44.8%

              \[\leadsto \color{blue}{\left(\sqrt{0.5} \cdot \cos th\right) \cdot \left(a2 \cdot a2\right)} \]
            8. Taylor expanded in th around 0

              \[\leadsto \frac{-1}{2} \cdot \left({a2}^{2} \cdot \left({th}^{2} \cdot \sqrt{\frac{1}{2}}\right)\right) + \color{blue}{{a2}^{2} \cdot \sqrt{\frac{1}{2}}} \]
            9. Step-by-step derivation
              1. Applied rewrites41.0%

                \[\leadsto \mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot \color{blue}{\left(\left(\sqrt{0.5} \cdot a2\right) \cdot a2\right)} \]

              if -1.00000000000000001e-119 < (+.f64 (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a1 a1)) (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a2 a2)))

              1. Initial program 99.5%

                \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
              2. Add Preprocessing
              3. Step-by-step derivation
                1. lift-+.f64N/A

                  \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
                2. lift-*.f64N/A

                  \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
                3. lift-*.f64N/A

                  \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
                4. distribute-lft-outN/A

                  \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
                5. *-commutativeN/A

                  \[\leadsto \color{blue}{\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \frac{\cos th}{\sqrt{2}}} \]
                6. lift-/.f64N/A

                  \[\leadsto \left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \color{blue}{\frac{\cos th}{\sqrt{2}}} \]
                7. clear-numN/A

                  \[\leadsto \left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \color{blue}{\frac{1}{\frac{\sqrt{2}}{\cos th}}} \]
                8. un-div-invN/A

                  \[\leadsto \color{blue}{\frac{a1 \cdot a1 + a2 \cdot a2}{\frac{\sqrt{2}}{\cos th}}} \]
                9. lower-/.f64N/A

                  \[\leadsto \color{blue}{\frac{a1 \cdot a1 + a2 \cdot a2}{\frac{\sqrt{2}}{\cos th}}} \]
                10. +-commutativeN/A

                  \[\leadsto \frac{\color{blue}{a2 \cdot a2 + a1 \cdot a1}}{\frac{\sqrt{2}}{\cos th}} \]
                11. lift-*.f64N/A

                  \[\leadsto \frac{\color{blue}{a2 \cdot a2} + a1 \cdot a1}{\frac{\sqrt{2}}{\cos th}} \]
                12. lower-fma.f64N/A

                  \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}}{\frac{\sqrt{2}}{\cos th}} \]
                13. lower-/.f6499.6

                  \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\frac{\sqrt{2}}{\cos th}}} \]
              4. Applied rewrites99.6%

                \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\frac{\sqrt{2}}{\cos th}}} \]
              5. Taylor expanded in th around 0

                \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
              6. Step-by-step derivation
                1. lower-sqrt.f6481.9

                  \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
              7. Applied rewrites81.9%

                \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
            10. Recombined 2 regimes into one program.
            11. Add Preprocessing

            Alternative 5: 99.6% accurate, 1.9× speedup?

            \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \cos th}{\sqrt{2}} \end{array} \]
            NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
            (FPCore (a1 a2 th)
             :precision binary64
             (/ (* (fma a2 a2 (* a1 a1)) (cos th)) (sqrt 2.0)))
            assert(a1 < a2 && a2 < th);
            double code(double a1, double a2, double th) {
            	return (fma(a2, a2, (a1 * a1)) * cos(th)) / sqrt(2.0);
            }
            
            a1, a2, th = sort([a1, a2, th])
            function code(a1, a2, th)
            	return Float64(Float64(fma(a2, a2, Float64(a1 * a1)) * cos(th)) / sqrt(2.0))
            end
            
            NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
            code[a1_, a2_, th_] := N[(N[(N[(a2 * a2 + N[(a1 * a1), $MachinePrecision]), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
            
            \begin{array}{l}
            [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
            \\
            \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \cos th}{\sqrt{2}}
            \end{array}
            
            Derivation
            1. Initial program 99.6%

              \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
            2. Add Preprocessing
            3. Step-by-step derivation
              1. lift-+.f64N/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
              2. lift-*.f64N/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
              3. lift-*.f64N/A

                \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
              4. distribute-lft-outN/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
              5. lift-/.f64N/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
              6. associate-*l/N/A

                \[\leadsto \color{blue}{\frac{\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)}{\sqrt{2}}} \]
              7. lower-/.f64N/A

                \[\leadsto \color{blue}{\frac{\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)}{\sqrt{2}}} \]
              8. *-commutativeN/A

                \[\leadsto \frac{\color{blue}{\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th}}{\sqrt{2}} \]
              9. lower-*.f64N/A

                \[\leadsto \frac{\color{blue}{\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th}}{\sqrt{2}} \]
              10. +-commutativeN/A

                \[\leadsto \frac{\color{blue}{\left(a2 \cdot a2 + a1 \cdot a1\right)} \cdot \cos th}{\sqrt{2}} \]
              11. lift-*.f64N/A

                \[\leadsto \frac{\left(\color{blue}{a2 \cdot a2} + a1 \cdot a1\right) \cdot \cos th}{\sqrt{2}} \]
              12. lower-fma.f6499.6

                \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)} \cdot \cos th}{\sqrt{2}} \]
            4. Applied rewrites99.6%

              \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \cos th}{\sqrt{2}}} \]
            5. Add Preprocessing

            Alternative 6: 99.6% accurate, 1.9× speedup?

            \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}} \cdot \cos th \end{array} \]
            NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
            (FPCore (a1 a2 th)
             :precision binary64
             (* (/ (fma a2 a2 (* a1 a1)) (sqrt 2.0)) (cos th)))
            assert(a1 < a2 && a2 < th);
            double code(double a1, double a2, double th) {
            	return (fma(a2, a2, (a1 * a1)) / sqrt(2.0)) * cos(th);
            }
            
            a1, a2, th = sort([a1, a2, th])
            function code(a1, a2, th)
            	return Float64(Float64(fma(a2, a2, Float64(a1 * a1)) / sqrt(2.0)) * cos(th))
            end
            
            NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
            code[a1_, a2_, th_] := N[(N[(N[(a2 * a2 + N[(a1 * a1), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision]
            
            \begin{array}{l}
            [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
            \\
            \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}} \cdot \cos th
            \end{array}
            
            Derivation
            1. Initial program 99.6%

              \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
            2. Add Preprocessing
            3. Step-by-step derivation
              1. lift-+.f64N/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
              2. lift-*.f64N/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
              3. lift-*.f64N/A

                \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
              4. distribute-lft-outN/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
              5. lift-/.f64N/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
              6. div-invN/A

                \[\leadsto \color{blue}{\left(\cos th \cdot \frac{1}{\sqrt{2}}\right)} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
              7. associate-*l*N/A

                \[\leadsto \color{blue}{\cos th \cdot \left(\frac{1}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
              8. *-commutativeN/A

                \[\leadsto \color{blue}{\left(\frac{1}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \cdot \cos th} \]
              9. lower-*.f64N/A

                \[\leadsto \color{blue}{\left(\frac{1}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \cdot \cos th} \]
              10. associate-*l/N/A

                \[\leadsto \color{blue}{\frac{1 \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)}{\sqrt{2}}} \cdot \cos th \]
              11. *-lft-identityN/A

                \[\leadsto \frac{\color{blue}{a1 \cdot a1 + a2 \cdot a2}}{\sqrt{2}} \cdot \cos th \]
              12. lower-/.f64N/A

                \[\leadsto \color{blue}{\frac{a1 \cdot a1 + a2 \cdot a2}{\sqrt{2}}} \cdot \cos th \]
              13. +-commutativeN/A

                \[\leadsto \frac{\color{blue}{a2 \cdot a2 + a1 \cdot a1}}{\sqrt{2}} \cdot \cos th \]
              14. lift-*.f64N/A

                \[\leadsto \frac{\color{blue}{a2 \cdot a2} + a1 \cdot a1}{\sqrt{2}} \cdot \cos th \]
              15. lower-fma.f6499.6

                \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}}{\sqrt{2}} \cdot \cos th \]
            4. Applied rewrites99.6%

              \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}} \cdot \cos th} \]
            5. Add Preprocessing

            Alternative 7: 99.6% accurate, 2.0× speedup?

            \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \left(\mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \cdot \cos th\right) \cdot \sqrt{0.5} \end{array} \]
            NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
            (FPCore (a1 a2 th)
             :precision binary64
             (* (* (fma a1 a1 (* a2 a2)) (cos th)) (sqrt 0.5)))
            assert(a1 < a2 && a2 < th);
            double code(double a1, double a2, double th) {
            	return (fma(a1, a1, (a2 * a2)) * cos(th)) * sqrt(0.5);
            }
            
            a1, a2, th = sort([a1, a2, th])
            function code(a1, a2, th)
            	return Float64(Float64(fma(a1, a1, Float64(a2 * a2)) * cos(th)) * sqrt(0.5))
            end
            
            NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
            code[a1_, a2_, th_] := N[(N[(N[(a1 * a1 + N[(a2 * a2), $MachinePrecision]), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision] * N[Sqrt[0.5], $MachinePrecision]), $MachinePrecision]
            
            \begin{array}{l}
            [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
            \\
            \left(\mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \cdot \cos th\right) \cdot \sqrt{0.5}
            \end{array}
            
            Derivation
            1. Initial program 99.6%

              \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
            2. Add Preprocessing
            3. Step-by-step derivation
              1. lift-+.f64N/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
              2. lift-*.f64N/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
              3. lift-*.f64N/A

                \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
              4. distribute-lft-outN/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
              5. lift-/.f64N/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
              6. clear-numN/A

                \[\leadsto \color{blue}{\frac{1}{\frac{\sqrt{2}}{\cos th}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
              7. associate-/r/N/A

                \[\leadsto \color{blue}{\left(\frac{1}{\sqrt{2}} \cdot \cos th\right)} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
              8. associate-*l*N/A

                \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
              9. lower-*.f64N/A

                \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
              10. lift-sqrt.f64N/A

                \[\leadsto \frac{1}{\color{blue}{\sqrt{2}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              11. pow1/2N/A

                \[\leadsto \frac{1}{\color{blue}{{2}^{\frac{1}{2}}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              12. pow-flipN/A

                \[\leadsto \color{blue}{{2}^{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              13. lower-pow.f64N/A

                \[\leadsto \color{blue}{{2}^{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              14. metadata-evalN/A

                \[\leadsto {2}^{\color{blue}{\frac{-1}{2}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              15. *-commutativeN/A

                \[\leadsto {2}^{\frac{-1}{2}} \cdot \color{blue}{\left(\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th\right)} \]
              16. lower-*.f64N/A

                \[\leadsto {2}^{\frac{-1}{2}} \cdot \color{blue}{\left(\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th\right)} \]
              17. +-commutativeN/A

                \[\leadsto {2}^{\frac{-1}{2}} \cdot \left(\color{blue}{\left(a2 \cdot a2 + a1 \cdot a1\right)} \cdot \cos th\right) \]
              18. lift-*.f64N/A

                \[\leadsto {2}^{\frac{-1}{2}} \cdot \left(\left(\color{blue}{a2 \cdot a2} + a1 \cdot a1\right) \cdot \cos th\right) \]
              19. lower-fma.f6499.6

                \[\leadsto {2}^{-0.5} \cdot \left(\color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)} \cdot \cos th\right) \]
            4. Applied rewrites99.6%

              \[\leadsto \color{blue}{{2}^{-0.5} \cdot \left(\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \cos th\right)} \]
            5. Taylor expanded in a1 around 0

              \[\leadsto \color{blue}{{a1}^{2} \cdot \left(\cos th \cdot \sqrt{\frac{1}{2}}\right) + {a2}^{2} \cdot \left(\cos th \cdot \sqrt{\frac{1}{2}}\right)} \]
            6. Step-by-step derivation
              1. distribute-rgt-outN/A

                \[\leadsto \color{blue}{\left(\cos th \cdot \sqrt{\frac{1}{2}}\right) \cdot \left({a1}^{2} + {a2}^{2}\right)} \]
              2. associate-*r*N/A

                \[\leadsto \color{blue}{\cos th \cdot \left(\sqrt{\frac{1}{2}} \cdot \left({a1}^{2} + {a2}^{2}\right)\right)} \]
              3. *-commutativeN/A

                \[\leadsto \cos th \cdot \color{blue}{\left(\left({a1}^{2} + {a2}^{2}\right) \cdot \sqrt{\frac{1}{2}}\right)} \]
              4. associate-*r*N/A

                \[\leadsto \color{blue}{\left(\cos th \cdot \left({a1}^{2} + {a2}^{2}\right)\right) \cdot \sqrt{\frac{1}{2}}} \]
              5. lower-*.f64N/A

                \[\leadsto \color{blue}{\left(\cos th \cdot \left({a1}^{2} + {a2}^{2}\right)\right) \cdot \sqrt{\frac{1}{2}}} \]
              6. *-commutativeN/A

                \[\leadsto \color{blue}{\left(\left({a1}^{2} + {a2}^{2}\right) \cdot \cos th\right)} \cdot \sqrt{\frac{1}{2}} \]
              7. lower-*.f64N/A

                \[\leadsto \color{blue}{\left(\left({a1}^{2} + {a2}^{2}\right) \cdot \cos th\right)} \cdot \sqrt{\frac{1}{2}} \]
              8. unpow2N/A

                \[\leadsto \left(\left(\color{blue}{a1 \cdot a1} + {a2}^{2}\right) \cdot \cos th\right) \cdot \sqrt{\frac{1}{2}} \]
              9. lower-fma.f64N/A

                \[\leadsto \left(\color{blue}{\mathsf{fma}\left(a1, a1, {a2}^{2}\right)} \cdot \cos th\right) \cdot \sqrt{\frac{1}{2}} \]
              10. unpow2N/A

                \[\leadsto \left(\mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \cdot \cos th\right) \cdot \sqrt{\frac{1}{2}} \]
              11. lower-*.f64N/A

                \[\leadsto \left(\mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \cdot \cos th\right) \cdot \sqrt{\frac{1}{2}} \]
              12. lower-cos.f64N/A

                \[\leadsto \left(\mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \cdot \color{blue}{\cos th}\right) \cdot \sqrt{\frac{1}{2}} \]
              13. lower-sqrt.f6499.6

                \[\leadsto \left(\mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \cdot \cos th\right) \cdot \color{blue}{\sqrt{0.5}} \]
            7. Applied rewrites99.6%

              \[\leadsto \color{blue}{\left(\mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \cdot \cos th\right) \cdot \sqrt{0.5}} \]
            8. Add Preprocessing

            Alternative 8: 57.4% accurate, 2.1× speedup?

            \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \left(\sqrt{0.5} \cdot \cos th\right) \cdot \left(a2 \cdot a2\right) \end{array} \]
            NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
            (FPCore (a1 a2 th) :precision binary64 (* (* (sqrt 0.5) (cos th)) (* a2 a2)))
            assert(a1 < a2 && a2 < th);
            double code(double a1, double a2, double th) {
            	return (sqrt(0.5) * cos(th)) * (a2 * a2);
            }
            
            NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
            real(8) function code(a1, a2, th)
                real(8), intent (in) :: a1
                real(8), intent (in) :: a2
                real(8), intent (in) :: th
                code = (sqrt(0.5d0) * cos(th)) * (a2 * a2)
            end function
            
            assert a1 < a2 && a2 < th;
            public static double code(double a1, double a2, double th) {
            	return (Math.sqrt(0.5) * Math.cos(th)) * (a2 * a2);
            }
            
            [a1, a2, th] = sort([a1, a2, th])
            def code(a1, a2, th):
            	return (math.sqrt(0.5) * math.cos(th)) * (a2 * a2)
            
            a1, a2, th = sort([a1, a2, th])
            function code(a1, a2, th)
            	return Float64(Float64(sqrt(0.5) * cos(th)) * Float64(a2 * a2))
            end
            
            a1, a2, th = num2cell(sort([a1, a2, th])){:}
            function tmp = code(a1, a2, th)
            	tmp = (sqrt(0.5) * cos(th)) * (a2 * a2);
            end
            
            NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
            code[a1_, a2_, th_] := N[(N[(N[Sqrt[0.5], $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision] * N[(a2 * a2), $MachinePrecision]), $MachinePrecision]
            
            \begin{array}{l}
            [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
            \\
            \left(\sqrt{0.5} \cdot \cos th\right) \cdot \left(a2 \cdot a2\right)
            \end{array}
            
            Derivation
            1. Initial program 99.6%

              \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
            2. Add Preprocessing
            3. Step-by-step derivation
              1. lift-+.f64N/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
              2. lift-*.f64N/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
              3. lift-*.f64N/A

                \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
              4. distribute-lft-outN/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
              5. lift-/.f64N/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
              6. clear-numN/A

                \[\leadsto \color{blue}{\frac{1}{\frac{\sqrt{2}}{\cos th}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
              7. associate-/r/N/A

                \[\leadsto \color{blue}{\left(\frac{1}{\sqrt{2}} \cdot \cos th\right)} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
              8. associate-*l*N/A

                \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
              9. lower-*.f64N/A

                \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
              10. lift-sqrt.f64N/A

                \[\leadsto \frac{1}{\color{blue}{\sqrt{2}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              11. pow1/2N/A

                \[\leadsto \frac{1}{\color{blue}{{2}^{\frac{1}{2}}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              12. pow-flipN/A

                \[\leadsto \color{blue}{{2}^{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              13. lower-pow.f64N/A

                \[\leadsto \color{blue}{{2}^{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              14. metadata-evalN/A

                \[\leadsto {2}^{\color{blue}{\frac{-1}{2}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              15. *-commutativeN/A

                \[\leadsto {2}^{\frac{-1}{2}} \cdot \color{blue}{\left(\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th\right)} \]
              16. lower-*.f64N/A

                \[\leadsto {2}^{\frac{-1}{2}} \cdot \color{blue}{\left(\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th\right)} \]
              17. +-commutativeN/A

                \[\leadsto {2}^{\frac{-1}{2}} \cdot \left(\color{blue}{\left(a2 \cdot a2 + a1 \cdot a1\right)} \cdot \cos th\right) \]
              18. lift-*.f64N/A

                \[\leadsto {2}^{\frac{-1}{2}} \cdot \left(\left(\color{blue}{a2 \cdot a2} + a1 \cdot a1\right) \cdot \cos th\right) \]
              19. lower-fma.f6499.6

                \[\leadsto {2}^{-0.5} \cdot \left(\color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)} \cdot \cos th\right) \]
            4. Applied rewrites99.6%

              \[\leadsto \color{blue}{{2}^{-0.5} \cdot \left(\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \cos th\right)} \]
            5. Taylor expanded in a1 around 0

              \[\leadsto \color{blue}{{a2}^{2} \cdot \left(\cos th \cdot \sqrt{\frac{1}{2}}\right)} \]
            6. Step-by-step derivation
              1. *-commutativeN/A

                \[\leadsto \color{blue}{\left(\cos th \cdot \sqrt{\frac{1}{2}}\right) \cdot {a2}^{2}} \]
              2. lower-*.f64N/A

                \[\leadsto \color{blue}{\left(\cos th \cdot \sqrt{\frac{1}{2}}\right) \cdot {a2}^{2}} \]
              3. *-commutativeN/A

                \[\leadsto \color{blue}{\left(\sqrt{\frac{1}{2}} \cdot \cos th\right)} \cdot {a2}^{2} \]
              4. lower-*.f64N/A

                \[\leadsto \color{blue}{\left(\sqrt{\frac{1}{2}} \cdot \cos th\right)} \cdot {a2}^{2} \]
              5. lower-sqrt.f64N/A

                \[\leadsto \left(\color{blue}{\sqrt{\frac{1}{2}}} \cdot \cos th\right) \cdot {a2}^{2} \]
              6. lower-cos.f64N/A

                \[\leadsto \left(\sqrt{\frac{1}{2}} \cdot \color{blue}{\cos th}\right) \cdot {a2}^{2} \]
              7. unpow2N/A

                \[\leadsto \left(\sqrt{\frac{1}{2}} \cdot \cos th\right) \cdot \color{blue}{\left(a2 \cdot a2\right)} \]
              8. lower-*.f6453.8

                \[\leadsto \left(\sqrt{0.5} \cdot \cos th\right) \cdot \color{blue}{\left(a2 \cdot a2\right)} \]
            7. Applied rewrites53.8%

              \[\leadsto \color{blue}{\left(\sqrt{0.5} \cdot \cos th\right) \cdot \left(a2 \cdot a2\right)} \]
            8. Add Preprocessing

            Alternative 9: 57.4% accurate, 2.1× speedup?

            \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \left(\left(a2 \cdot a2\right) \cdot \cos th\right) \cdot \sqrt{0.5} \end{array} \]
            NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
            (FPCore (a1 a2 th) :precision binary64 (* (* (* a2 a2) (cos th)) (sqrt 0.5)))
            assert(a1 < a2 && a2 < th);
            double code(double a1, double a2, double th) {
            	return ((a2 * a2) * cos(th)) * sqrt(0.5);
            }
            
            NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
            real(8) function code(a1, a2, th)
                real(8), intent (in) :: a1
                real(8), intent (in) :: a2
                real(8), intent (in) :: th
                code = ((a2 * a2) * cos(th)) * sqrt(0.5d0)
            end function
            
            assert a1 < a2 && a2 < th;
            public static double code(double a1, double a2, double th) {
            	return ((a2 * a2) * Math.cos(th)) * Math.sqrt(0.5);
            }
            
            [a1, a2, th] = sort([a1, a2, th])
            def code(a1, a2, th):
            	return ((a2 * a2) * math.cos(th)) * math.sqrt(0.5)
            
            a1, a2, th = sort([a1, a2, th])
            function code(a1, a2, th)
            	return Float64(Float64(Float64(a2 * a2) * cos(th)) * sqrt(0.5))
            end
            
            a1, a2, th = num2cell(sort([a1, a2, th])){:}
            function tmp = code(a1, a2, th)
            	tmp = ((a2 * a2) * cos(th)) * sqrt(0.5);
            end
            
            NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
            code[a1_, a2_, th_] := N[(N[(N[(a2 * a2), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision] * N[Sqrt[0.5], $MachinePrecision]), $MachinePrecision]
            
            \begin{array}{l}
            [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
            \\
            \left(\left(a2 \cdot a2\right) \cdot \cos th\right) \cdot \sqrt{0.5}
            \end{array}
            
            Derivation
            1. Initial program 99.6%

              \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
            2. Add Preprocessing
            3. Step-by-step derivation
              1. lift-+.f64N/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
              2. lift-*.f64N/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
              3. lift-*.f64N/A

                \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
              4. distribute-lft-outN/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
              5. lift-/.f64N/A

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
              6. clear-numN/A

                \[\leadsto \color{blue}{\frac{1}{\frac{\sqrt{2}}{\cos th}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
              7. associate-/r/N/A

                \[\leadsto \color{blue}{\left(\frac{1}{\sqrt{2}} \cdot \cos th\right)} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
              8. associate-*l*N/A

                \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
              9. lower-*.f64N/A

                \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
              10. lift-sqrt.f64N/A

                \[\leadsto \frac{1}{\color{blue}{\sqrt{2}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              11. pow1/2N/A

                \[\leadsto \frac{1}{\color{blue}{{2}^{\frac{1}{2}}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              12. pow-flipN/A

                \[\leadsto \color{blue}{{2}^{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              13. lower-pow.f64N/A

                \[\leadsto \color{blue}{{2}^{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              14. metadata-evalN/A

                \[\leadsto {2}^{\color{blue}{\frac{-1}{2}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
              15. *-commutativeN/A

                \[\leadsto {2}^{\frac{-1}{2}} \cdot \color{blue}{\left(\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th\right)} \]
              16. lower-*.f64N/A

                \[\leadsto {2}^{\frac{-1}{2}} \cdot \color{blue}{\left(\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th\right)} \]
              17. +-commutativeN/A

                \[\leadsto {2}^{\frac{-1}{2}} \cdot \left(\color{blue}{\left(a2 \cdot a2 + a1 \cdot a1\right)} \cdot \cos th\right) \]
              18. lift-*.f64N/A

                \[\leadsto {2}^{\frac{-1}{2}} \cdot \left(\left(\color{blue}{a2 \cdot a2} + a1 \cdot a1\right) \cdot \cos th\right) \]
              19. lower-fma.f6499.6

                \[\leadsto {2}^{-0.5} \cdot \left(\color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)} \cdot \cos th\right) \]
            4. Applied rewrites99.6%

              \[\leadsto \color{blue}{{2}^{-0.5} \cdot \left(\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \cos th\right)} \]
            5. Taylor expanded in a1 around 0

              \[\leadsto \color{blue}{{a1}^{2} \cdot \left(\cos th \cdot \sqrt{\frac{1}{2}}\right) + {a2}^{2} \cdot \left(\cos th \cdot \sqrt{\frac{1}{2}}\right)} \]
            6. Step-by-step derivation
              1. distribute-rgt-outN/A

                \[\leadsto \color{blue}{\left(\cos th \cdot \sqrt{\frac{1}{2}}\right) \cdot \left({a1}^{2} + {a2}^{2}\right)} \]
              2. associate-*r*N/A

                \[\leadsto \color{blue}{\cos th \cdot \left(\sqrt{\frac{1}{2}} \cdot \left({a1}^{2} + {a2}^{2}\right)\right)} \]
              3. *-commutativeN/A

                \[\leadsto \cos th \cdot \color{blue}{\left(\left({a1}^{2} + {a2}^{2}\right) \cdot \sqrt{\frac{1}{2}}\right)} \]
              4. associate-*r*N/A

                \[\leadsto \color{blue}{\left(\cos th \cdot \left({a1}^{2} + {a2}^{2}\right)\right) \cdot \sqrt{\frac{1}{2}}} \]
              5. lower-*.f64N/A

                \[\leadsto \color{blue}{\left(\cos th \cdot \left({a1}^{2} + {a2}^{2}\right)\right) \cdot \sqrt{\frac{1}{2}}} \]
              6. *-commutativeN/A

                \[\leadsto \color{blue}{\left(\left({a1}^{2} + {a2}^{2}\right) \cdot \cos th\right)} \cdot \sqrt{\frac{1}{2}} \]
              7. lower-*.f64N/A

                \[\leadsto \color{blue}{\left(\left({a1}^{2} + {a2}^{2}\right) \cdot \cos th\right)} \cdot \sqrt{\frac{1}{2}} \]
              8. unpow2N/A

                \[\leadsto \left(\left(\color{blue}{a1 \cdot a1} + {a2}^{2}\right) \cdot \cos th\right) \cdot \sqrt{\frac{1}{2}} \]
              9. lower-fma.f64N/A

                \[\leadsto \left(\color{blue}{\mathsf{fma}\left(a1, a1, {a2}^{2}\right)} \cdot \cos th\right) \cdot \sqrt{\frac{1}{2}} \]
              10. unpow2N/A

                \[\leadsto \left(\mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \cdot \cos th\right) \cdot \sqrt{\frac{1}{2}} \]
              11. lower-*.f64N/A

                \[\leadsto \left(\mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \cdot \cos th\right) \cdot \sqrt{\frac{1}{2}} \]
              12. lower-cos.f64N/A

                \[\leadsto \left(\mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \cdot \color{blue}{\cos th}\right) \cdot \sqrt{\frac{1}{2}} \]
              13. lower-sqrt.f6499.6

                \[\leadsto \left(\mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \cdot \cos th\right) \cdot \color{blue}{\sqrt{0.5}} \]
            7. Applied rewrites99.6%

              \[\leadsto \color{blue}{\left(\mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \cdot \cos th\right) \cdot \sqrt{0.5}} \]
            8. Taylor expanded in a1 around 0

              \[\leadsto \left({a2}^{2} \cdot \cos th\right) \cdot \sqrt{\frac{1}{2}} \]
            9. Step-by-step derivation
              1. Applied rewrites53.7%

                \[\leadsto \left(\left(a2 \cdot a2\right) \cdot \cos th\right) \cdot \sqrt{0.5} \]
              2. Add Preprocessing

              Alternative 10: 66.2% accurate, 8.1× speedup?

              \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}} \end{array} \]
              NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
              (FPCore (a1 a2 th) :precision binary64 (/ (fma a2 a2 (* a1 a1)) (sqrt 2.0)))
              assert(a1 < a2 && a2 < th);
              double code(double a1, double a2, double th) {
              	return fma(a2, a2, (a1 * a1)) / sqrt(2.0);
              }
              
              a1, a2, th = sort([a1, a2, th])
              function code(a1, a2, th)
              	return Float64(fma(a2, a2, Float64(a1 * a1)) / sqrt(2.0))
              end
              
              NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
              code[a1_, a2_, th_] := N[(N[(a2 * a2 + N[(a1 * a1), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
              
              \begin{array}{l}
              [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
              \\
              \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}}
              \end{array}
              
              Derivation
              1. Initial program 99.6%

                \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
              2. Add Preprocessing
              3. Step-by-step derivation
                1. lift-+.f64N/A

                  \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
                2. lift-*.f64N/A

                  \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
                3. lift-*.f64N/A

                  \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
                4. distribute-lft-outN/A

                  \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
                5. *-commutativeN/A

                  \[\leadsto \color{blue}{\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \frac{\cos th}{\sqrt{2}}} \]
                6. lift-/.f64N/A

                  \[\leadsto \left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \color{blue}{\frac{\cos th}{\sqrt{2}}} \]
                7. clear-numN/A

                  \[\leadsto \left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \color{blue}{\frac{1}{\frac{\sqrt{2}}{\cos th}}} \]
                8. un-div-invN/A

                  \[\leadsto \color{blue}{\frac{a1 \cdot a1 + a2 \cdot a2}{\frac{\sqrt{2}}{\cos th}}} \]
                9. lower-/.f64N/A

                  \[\leadsto \color{blue}{\frac{a1 \cdot a1 + a2 \cdot a2}{\frac{\sqrt{2}}{\cos th}}} \]
                10. +-commutativeN/A

                  \[\leadsto \frac{\color{blue}{a2 \cdot a2 + a1 \cdot a1}}{\frac{\sqrt{2}}{\cos th}} \]
                11. lift-*.f64N/A

                  \[\leadsto \frac{\color{blue}{a2 \cdot a2} + a1 \cdot a1}{\frac{\sqrt{2}}{\cos th}} \]
                12. lower-fma.f64N/A

                  \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}}{\frac{\sqrt{2}}{\cos th}} \]
                13. lower-/.f6499.6

                  \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\frac{\sqrt{2}}{\cos th}}} \]
              4. Applied rewrites99.6%

                \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\frac{\sqrt{2}}{\cos th}}} \]
              5. Taylor expanded in th around 0

                \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
              6. Step-by-step derivation
                1. lower-sqrt.f6466.4

                  \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
              7. Applied rewrites66.4%

                \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
              8. Add Preprocessing

              Alternative 11: 66.2% accurate, 9.9× speedup?

              \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \sqrt{0.5} \cdot \mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \end{array} \]
              NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
              (FPCore (a1 a2 th) :precision binary64 (* (sqrt 0.5) (fma a1 a1 (* a2 a2))))
              assert(a1 < a2 && a2 < th);
              double code(double a1, double a2, double th) {
              	return sqrt(0.5) * fma(a1, a1, (a2 * a2));
              }
              
              a1, a2, th = sort([a1, a2, th])
              function code(a1, a2, th)
              	return Float64(sqrt(0.5) * fma(a1, a1, Float64(a2 * a2)))
              end
              
              NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
              code[a1_, a2_, th_] := N[(N[Sqrt[0.5], $MachinePrecision] * N[(a1 * a1 + N[(a2 * a2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
              
              \begin{array}{l}
              [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
              \\
              \sqrt{0.5} \cdot \mathsf{fma}\left(a1, a1, a2 \cdot a2\right)
              \end{array}
              
              Derivation
              1. Initial program 99.6%

                \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
              2. Add Preprocessing
              3. Step-by-step derivation
                1. lift-+.f64N/A

                  \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
                2. lift-*.f64N/A

                  \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
                3. lift-*.f64N/A

                  \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
                4. distribute-lft-outN/A

                  \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
                5. lift-/.f64N/A

                  \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
                6. clear-numN/A

                  \[\leadsto \color{blue}{\frac{1}{\frac{\sqrt{2}}{\cos th}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
                7. associate-/r/N/A

                  \[\leadsto \color{blue}{\left(\frac{1}{\sqrt{2}} \cdot \cos th\right)} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
                8. associate-*l*N/A

                  \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
                9. lower-*.f64N/A

                  \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
                10. lift-sqrt.f64N/A

                  \[\leadsto \frac{1}{\color{blue}{\sqrt{2}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
                11. pow1/2N/A

                  \[\leadsto \frac{1}{\color{blue}{{2}^{\frac{1}{2}}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
                12. pow-flipN/A

                  \[\leadsto \color{blue}{{2}^{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
                13. lower-pow.f64N/A

                  \[\leadsto \color{blue}{{2}^{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
                14. metadata-evalN/A

                  \[\leadsto {2}^{\color{blue}{\frac{-1}{2}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
                15. *-commutativeN/A

                  \[\leadsto {2}^{\frac{-1}{2}} \cdot \color{blue}{\left(\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th\right)} \]
                16. lower-*.f64N/A

                  \[\leadsto {2}^{\frac{-1}{2}} \cdot \color{blue}{\left(\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th\right)} \]
                17. +-commutativeN/A

                  \[\leadsto {2}^{\frac{-1}{2}} \cdot \left(\color{blue}{\left(a2 \cdot a2 + a1 \cdot a1\right)} \cdot \cos th\right) \]
                18. lift-*.f64N/A

                  \[\leadsto {2}^{\frac{-1}{2}} \cdot \left(\left(\color{blue}{a2 \cdot a2} + a1 \cdot a1\right) \cdot \cos th\right) \]
                19. lower-fma.f6499.6

                  \[\leadsto {2}^{-0.5} \cdot \left(\color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)} \cdot \cos th\right) \]
              4. Applied rewrites99.6%

                \[\leadsto \color{blue}{{2}^{-0.5} \cdot \left(\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \cos th\right)} \]
              5. Taylor expanded in th around 0

                \[\leadsto \color{blue}{\sqrt{\frac{1}{2}} \cdot \left({a1}^{2} + {a2}^{2}\right)} \]
              6. Step-by-step derivation
                1. lower-*.f64N/A

                  \[\leadsto \color{blue}{\sqrt{\frac{1}{2}} \cdot \left({a1}^{2} + {a2}^{2}\right)} \]
                2. lower-sqrt.f64N/A

                  \[\leadsto \color{blue}{\sqrt{\frac{1}{2}}} \cdot \left({a1}^{2} + {a2}^{2}\right) \]
                3. unpow2N/A

                  \[\leadsto \sqrt{\frac{1}{2}} \cdot \left(\color{blue}{a1 \cdot a1} + {a2}^{2}\right) \]
                4. lower-fma.f64N/A

                  \[\leadsto \sqrt{\frac{1}{2}} \cdot \color{blue}{\mathsf{fma}\left(a1, a1, {a2}^{2}\right)} \]
                5. unpow2N/A

                  \[\leadsto \sqrt{\frac{1}{2}} \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \]
                6. lower-*.f6466.3

                  \[\leadsto \sqrt{0.5} \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \]
              7. Applied rewrites66.3%

                \[\leadsto \color{blue}{\sqrt{0.5} \cdot \mathsf{fma}\left(a1, a1, a2 \cdot a2\right)} \]
              8. Add Preprocessing

              Alternative 12: 39.5% accurate, 12.7× speedup?

              \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \left(\sqrt{0.5} \cdot a2\right) \cdot a2 \end{array} \]
              NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
              (FPCore (a1 a2 th) :precision binary64 (* (* (sqrt 0.5) a2) a2))
              assert(a1 < a2 && a2 < th);
              double code(double a1, double a2, double th) {
              	return (sqrt(0.5) * a2) * a2;
              }
              
              NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
              real(8) function code(a1, a2, th)
                  real(8), intent (in) :: a1
                  real(8), intent (in) :: a2
                  real(8), intent (in) :: th
                  code = (sqrt(0.5d0) * a2) * a2
              end function
              
              assert a1 < a2 && a2 < th;
              public static double code(double a1, double a2, double th) {
              	return (Math.sqrt(0.5) * a2) * a2;
              }
              
              [a1, a2, th] = sort([a1, a2, th])
              def code(a1, a2, th):
              	return (math.sqrt(0.5) * a2) * a2
              
              a1, a2, th = sort([a1, a2, th])
              function code(a1, a2, th)
              	return Float64(Float64(sqrt(0.5) * a2) * a2)
              end
              
              a1, a2, th = num2cell(sort([a1, a2, th])){:}
              function tmp = code(a1, a2, th)
              	tmp = (sqrt(0.5) * a2) * a2;
              end
              
              NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
              code[a1_, a2_, th_] := N[(N[(N[Sqrt[0.5], $MachinePrecision] * a2), $MachinePrecision] * a2), $MachinePrecision]
              
              \begin{array}{l}
              [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
              \\
              \left(\sqrt{0.5} \cdot a2\right) \cdot a2
              \end{array}
              
              Derivation
              1. Initial program 99.6%

                \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
              2. Add Preprocessing
              3. Step-by-step derivation
                1. lift-+.f64N/A

                  \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
                2. lift-*.f64N/A

                  \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
                3. lift-*.f64N/A

                  \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
                4. distribute-lft-outN/A

                  \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
                5. lift-/.f64N/A

                  \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
                6. clear-numN/A

                  \[\leadsto \color{blue}{\frac{1}{\frac{\sqrt{2}}{\cos th}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
                7. associate-/r/N/A

                  \[\leadsto \color{blue}{\left(\frac{1}{\sqrt{2}} \cdot \cos th\right)} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
                8. associate-*l*N/A

                  \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
                9. lower-*.f64N/A

                  \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
                10. lift-sqrt.f64N/A

                  \[\leadsto \frac{1}{\color{blue}{\sqrt{2}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
                11. pow1/2N/A

                  \[\leadsto \frac{1}{\color{blue}{{2}^{\frac{1}{2}}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
                12. pow-flipN/A

                  \[\leadsto \color{blue}{{2}^{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
                13. lower-pow.f64N/A

                  \[\leadsto \color{blue}{{2}^{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
                14. metadata-evalN/A

                  \[\leadsto {2}^{\color{blue}{\frac{-1}{2}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
                15. *-commutativeN/A

                  \[\leadsto {2}^{\frac{-1}{2}} \cdot \color{blue}{\left(\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th\right)} \]
                16. lower-*.f64N/A

                  \[\leadsto {2}^{\frac{-1}{2}} \cdot \color{blue}{\left(\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th\right)} \]
                17. +-commutativeN/A

                  \[\leadsto {2}^{\frac{-1}{2}} \cdot \left(\color{blue}{\left(a2 \cdot a2 + a1 \cdot a1\right)} \cdot \cos th\right) \]
                18. lift-*.f64N/A

                  \[\leadsto {2}^{\frac{-1}{2}} \cdot \left(\left(\color{blue}{a2 \cdot a2} + a1 \cdot a1\right) \cdot \cos th\right) \]
                19. lower-fma.f6499.6

                  \[\leadsto {2}^{-0.5} \cdot \left(\color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)} \cdot \cos th\right) \]
              4. Applied rewrites99.6%

                \[\leadsto \color{blue}{{2}^{-0.5} \cdot \left(\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \cos th\right)} \]
              5. Taylor expanded in th around 0

                \[\leadsto \color{blue}{\sqrt{\frac{1}{2}} \cdot \left({a1}^{2} + {a2}^{2}\right)} \]
              6. Step-by-step derivation
                1. lower-*.f64N/A

                  \[\leadsto \color{blue}{\sqrt{\frac{1}{2}} \cdot \left({a1}^{2} + {a2}^{2}\right)} \]
                2. lower-sqrt.f64N/A

                  \[\leadsto \color{blue}{\sqrt{\frac{1}{2}}} \cdot \left({a1}^{2} + {a2}^{2}\right) \]
                3. unpow2N/A

                  \[\leadsto \sqrt{\frac{1}{2}} \cdot \left(\color{blue}{a1 \cdot a1} + {a2}^{2}\right) \]
                4. lower-fma.f64N/A

                  \[\leadsto \sqrt{\frac{1}{2}} \cdot \color{blue}{\mathsf{fma}\left(a1, a1, {a2}^{2}\right)} \]
                5. unpow2N/A

                  \[\leadsto \sqrt{\frac{1}{2}} \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \]
                6. lower-*.f6466.3

                  \[\leadsto \sqrt{0.5} \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \]
              7. Applied rewrites66.3%

                \[\leadsto \color{blue}{\sqrt{0.5} \cdot \mathsf{fma}\left(a1, a1, a2 \cdot a2\right)} \]
              8. Taylor expanded in a1 around 0

                \[\leadsto {a2}^{2} \cdot \color{blue}{\sqrt{\frac{1}{2}}} \]
              9. Step-by-step derivation
                1. Applied rewrites38.3%

                  \[\leadsto \left(\sqrt{0.5} \cdot a2\right) \cdot \color{blue}{a2} \]
                2. Add Preprocessing

                Alternative 13: 39.8% accurate, 12.7× speedup?

                \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \left(\sqrt{0.5} \cdot a1\right) \cdot a1 \end{array} \]
                NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
                (FPCore (a1 a2 th) :precision binary64 (* (* (sqrt 0.5) a1) a1))
                assert(a1 < a2 && a2 < th);
                double code(double a1, double a2, double th) {
                	return (sqrt(0.5) * a1) * a1;
                }
                
                NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
                real(8) function code(a1, a2, th)
                    real(8), intent (in) :: a1
                    real(8), intent (in) :: a2
                    real(8), intent (in) :: th
                    code = (sqrt(0.5d0) * a1) * a1
                end function
                
                assert a1 < a2 && a2 < th;
                public static double code(double a1, double a2, double th) {
                	return (Math.sqrt(0.5) * a1) * a1;
                }
                
                [a1, a2, th] = sort([a1, a2, th])
                def code(a1, a2, th):
                	return (math.sqrt(0.5) * a1) * a1
                
                a1, a2, th = sort([a1, a2, th])
                function code(a1, a2, th)
                	return Float64(Float64(sqrt(0.5) * a1) * a1)
                end
                
                a1, a2, th = num2cell(sort([a1, a2, th])){:}
                function tmp = code(a1, a2, th)
                	tmp = (sqrt(0.5) * a1) * a1;
                end
                
                NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
                code[a1_, a2_, th_] := N[(N[(N[Sqrt[0.5], $MachinePrecision] * a1), $MachinePrecision] * a1), $MachinePrecision]
                
                \begin{array}{l}
                [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
                \\
                \left(\sqrt{0.5} \cdot a1\right) \cdot a1
                \end{array}
                
                Derivation
                1. Initial program 99.6%

                  \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
                2. Add Preprocessing
                3. Step-by-step derivation
                  1. lift-+.f64N/A

                    \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
                  2. lift-*.f64N/A

                    \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
                  3. lift-*.f64N/A

                    \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
                  4. distribute-lft-outN/A

                    \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
                  5. lift-/.f64N/A

                    \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
                  6. clear-numN/A

                    \[\leadsto \color{blue}{\frac{1}{\frac{\sqrt{2}}{\cos th}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
                  7. associate-/r/N/A

                    \[\leadsto \color{blue}{\left(\frac{1}{\sqrt{2}} \cdot \cos th\right)} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
                  8. associate-*l*N/A

                    \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
                  9. lower-*.f64N/A

                    \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
                  10. lift-sqrt.f64N/A

                    \[\leadsto \frac{1}{\color{blue}{\sqrt{2}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
                  11. pow1/2N/A

                    \[\leadsto \frac{1}{\color{blue}{{2}^{\frac{1}{2}}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
                  12. pow-flipN/A

                    \[\leadsto \color{blue}{{2}^{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
                  13. lower-pow.f64N/A

                    \[\leadsto \color{blue}{{2}^{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
                  14. metadata-evalN/A

                    \[\leadsto {2}^{\color{blue}{\frac{-1}{2}}} \cdot \left(\cos th \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \]
                  15. *-commutativeN/A

                    \[\leadsto {2}^{\frac{-1}{2}} \cdot \color{blue}{\left(\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th\right)} \]
                  16. lower-*.f64N/A

                    \[\leadsto {2}^{\frac{-1}{2}} \cdot \color{blue}{\left(\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \cos th\right)} \]
                  17. +-commutativeN/A

                    \[\leadsto {2}^{\frac{-1}{2}} \cdot \left(\color{blue}{\left(a2 \cdot a2 + a1 \cdot a1\right)} \cdot \cos th\right) \]
                  18. lift-*.f64N/A

                    \[\leadsto {2}^{\frac{-1}{2}} \cdot \left(\left(\color{blue}{a2 \cdot a2} + a1 \cdot a1\right) \cdot \cos th\right) \]
                  19. lower-fma.f6499.6

                    \[\leadsto {2}^{-0.5} \cdot \left(\color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)} \cdot \cos th\right) \]
                4. Applied rewrites99.6%

                  \[\leadsto \color{blue}{{2}^{-0.5} \cdot \left(\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \cos th\right)} \]
                5. Taylor expanded in th around 0

                  \[\leadsto \color{blue}{\sqrt{\frac{1}{2}} \cdot \left({a1}^{2} + {a2}^{2}\right)} \]
                6. Step-by-step derivation
                  1. lower-*.f64N/A

                    \[\leadsto \color{blue}{\sqrt{\frac{1}{2}} \cdot \left({a1}^{2} + {a2}^{2}\right)} \]
                  2. lower-sqrt.f64N/A

                    \[\leadsto \color{blue}{\sqrt{\frac{1}{2}}} \cdot \left({a1}^{2} + {a2}^{2}\right) \]
                  3. unpow2N/A

                    \[\leadsto \sqrt{\frac{1}{2}} \cdot \left(\color{blue}{a1 \cdot a1} + {a2}^{2}\right) \]
                  4. lower-fma.f64N/A

                    \[\leadsto \sqrt{\frac{1}{2}} \cdot \color{blue}{\mathsf{fma}\left(a1, a1, {a2}^{2}\right)} \]
                  5. unpow2N/A

                    \[\leadsto \sqrt{\frac{1}{2}} \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \]
                  6. lower-*.f6466.3

                    \[\leadsto \sqrt{0.5} \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \]
                7. Applied rewrites66.3%

                  \[\leadsto \color{blue}{\sqrt{0.5} \cdot \mathsf{fma}\left(a1, a1, a2 \cdot a2\right)} \]
                8. Taylor expanded in a1 around inf

                  \[\leadsto {a1}^{2} \cdot \color{blue}{\sqrt{\frac{1}{2}}} \]
                9. Step-by-step derivation
                  1. Applied rewrites40.2%

                    \[\leadsto \left(\sqrt{0.5} \cdot a1\right) \cdot \color{blue}{a1} \]
                  2. Add Preprocessing

                  Reproduce

                  ?
                  herbie shell --seed 2024299 
                  (FPCore (a1 a2 th)
                    :name "Migdal et al, Equation (64)"
                    :precision binary64
                    (+ (* (/ (cos th) (sqrt 2.0)) (* a1 a1)) (* (/ (cos th) (sqrt 2.0)) (* a2 a2))))