Migdal et al, Equation (64)

Percentage Accurate: 99.5% → 99.6%
Time: 9.0s
Alternatives: 13
Speedup: 1.9×

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: 99.5% 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?

\[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \frac{\mathsf{fma}\left(\left(a2 \cdot \cos th\right) \cdot \left(-a2\right), -\sqrt{2}, \sqrt{2} \cdot \left(\left(a1 \cdot \cos th\right) \cdot a1\right)\right)}{2} \end{array} \]
NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
(FPCore (a1 a2 th)
 :precision binary64
 (/
  (fma
   (* (* a2 (cos th)) (- a2))
   (- (sqrt 2.0))
   (* (sqrt 2.0) (* (* a1 (cos th)) a1)))
  2.0))
assert(a1 < a2 && a2 < th);
double code(double a1, double a2, double th) {
	return fma(((a2 * cos(th)) * -a2), -sqrt(2.0), (sqrt(2.0) * ((a1 * cos(th)) * a1))) / 2.0;
}
a1, a2, th = sort([a1, a2, th])
function code(a1, a2, th)
	return Float64(fma(Float64(Float64(a2 * cos(th)) * Float64(-a2)), Float64(-sqrt(2.0)), Float64(sqrt(2.0) * Float64(Float64(a1 * cos(th)) * a1))) / 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[(N[(a2 * N[Cos[th], $MachinePrecision]), $MachinePrecision] * (-a2)), $MachinePrecision] * (-N[Sqrt[2.0], $MachinePrecision]) + N[(N[Sqrt[2.0], $MachinePrecision] * N[(N[(a1 * N[Cos[th], $MachinePrecision]), $MachinePrecision] * a1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision]
\begin{array}{l}
[a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
\\
\frac{\mathsf{fma}\left(\left(a2 \cdot \cos th\right) \cdot \left(-a2\right), -\sqrt{2}, \sqrt{2} \cdot \left(\left(a1 \cdot \cos th\right) \cdot a1\right)\right)}{2}
\end{array}
Derivation
  1. Initial program 99.3%

    \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
  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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{\left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{2}\right)\right) + \left(\mathsf{neg}\left(\sqrt{2}\right)\right) \cdot \left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a1 \cdot a1\right)\right)}{\sqrt{2} \cdot \color{blue}{\sqrt{2}}} \]
    15. rem-square-sqrtN/A

      \[\leadsto \frac{\left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{2}\right)\right) + \left(\mathsf{neg}\left(\sqrt{2}\right)\right) \cdot \left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a1 \cdot a1\right)\right)}{\color{blue}{2}} \]
  4. Applied rewrites99.7%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\left(a2 \cdot \cos th\right) \cdot \left(-a2\right), -\sqrt{2}, \left(-\sqrt{2}\right) \cdot \left(\left(a1 \cdot \cos th\right) \cdot \left(-a1\right)\right)\right)}{2}} \]
  5. Final simplification99.7%

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

Alternative 2: 74.5% accurate, 0.8× speedup?

\[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \begin{array}{l} t_1 := \frac{\cos th}{\sqrt{2}}\\ \mathbf{if}\;t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right) \leq -5 \cdot 10^{-274}:\\ \;\;\;\;\left(a2 \cdot a2\right) \cdot \frac{\mathsf{fma}\left(th \cdot th, -0.5, 1\right)}{\sqrt{2}}\\ \mathbf{else}:\\ \;\;\;\;\left(0.5 \cdot \sqrt{2}\right) \cdot \mathsf{fma}\left(a1, a1, a2 \cdot a2\right)\\ \end{array} \end{array} \]
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))) -5e-274)
     (* (* a2 a2) (/ (fma (* th th) -0.5 1.0) (sqrt 2.0)))
     (* (* 0.5 (sqrt 2.0)) (fma a1 a1 (* a2 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))) <= -5e-274) {
		tmp = (a2 * a2) * (fma((th * th), -0.5, 1.0) / sqrt(2.0));
	} else {
		tmp = (0.5 * sqrt(2.0)) * fma(a1, a1, (a2 * 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))) <= -5e-274)
		tmp = Float64(Float64(a2 * a2) * Float64(fma(Float64(th * th), -0.5, 1.0) / sqrt(2.0)));
	else
		tmp = Float64(Float64(0.5 * sqrt(2.0)) * fma(a1, a1, Float64(a2 * 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], -5e-274], N[(N[(a2 * a2), $MachinePrecision] * N[(N[(N[(th * th), $MachinePrecision] * -0.5 + 1.0), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(0.5 * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[(a1 * a1 + N[(a2 * 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 -5 \cdot 10^{-274}:\\
\;\;\;\;\left(a2 \cdot a2\right) \cdot \frac{\mathsf{fma}\left(th \cdot th, -0.5, 1\right)}{\sqrt{2}}\\

\mathbf{else}:\\
\;\;\;\;\left(0.5 \cdot \sqrt{2}\right) \cdot \mathsf{fma}\left(a1, a1, a2 \cdot 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))) < -5e-274

    1. Initial program 98.3%

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

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

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

        \[\leadsto \left(\color{blue}{a2 \cdot a2} + a1 \cdot a1\right) \cdot \frac{\cos th}{\sqrt{2}} \]
      9. lower-fma.f6498.3

        \[\leadsto \color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)} \cdot \frac{\cos th}{\sqrt{2}} \]
    4. Applied rewrites98.3%

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

      \[\leadsto \color{blue}{{a2}^{2}} \cdot \frac{\cos th}{\sqrt{2}} \]
    6. Step-by-step derivation
      1. unpow2N/A

        \[\leadsto \color{blue}{\left(a2 \cdot a2\right)} \cdot \frac{\cos th}{\sqrt{2}} \]
      2. lower-*.f6447.1

        \[\leadsto \color{blue}{\left(a2 \cdot a2\right)} \cdot \frac{\cos th}{\sqrt{2}} \]
    7. Applied rewrites47.1%

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

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

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

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

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

        \[\leadsto \left(a2 \cdot a2\right) \cdot \frac{\mathsf{fma}\left(\color{blue}{th \cdot th}, \frac{-1}{2}, 1\right)}{\sqrt{2}} \]
      5. lower-*.f6434.3

        \[\leadsto \left(a2 \cdot a2\right) \cdot \frac{\mathsf{fma}\left(\color{blue}{th \cdot th}, -0.5, 1\right)}{\sqrt{2}} \]
    10. Applied rewrites34.3%

      \[\leadsto \left(a2 \cdot a2\right) \cdot \frac{\color{blue}{\mathsf{fma}\left(th \cdot th, -0.5, 1\right)}}{\sqrt{2}} \]

    if -5e-274 < (+.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 99.6%

      \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{2}\right)\right) + \left(\mathsf{neg}\left(\sqrt{2}\right)\right) \cdot \left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a1 \cdot a1\right)\right)}{\sqrt{2} \cdot \color{blue}{\sqrt{2}}} \]
      15. rem-square-sqrtN/A

        \[\leadsto \frac{\left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{2}\right)\right) + \left(\mathsf{neg}\left(\sqrt{2}\right)\right) \cdot \left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a1 \cdot a1\right)\right)}{\color{blue}{2}} \]
    4. Applied rewrites99.7%

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(\frac{1}{2} \cdot \sqrt{2}\right) \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \]
      9. lower-*.f6484.2

        \[\leadsto \left(0.5 \cdot \sqrt{2}\right) \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \]
    7. Applied rewrites84.2%

      \[\leadsto \color{blue}{\left(0.5 \cdot \sqrt{2}\right) \cdot \mathsf{fma}\left(a1, a1, a2 \cdot a2\right)} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 3: 77.4% accurate, 0.8× speedup?

\[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \begin{array}{l} t_1 := \frac{\cos th}{\sqrt{2}}\\ t_2 := \mathsf{fma}\left(a1, a1, a2 \cdot a2\right)\\ \mathbf{if}\;t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right) \leq -5 \cdot 10^{-274}:\\ \;\;\;\;\left(\sqrt{2} \cdot \mathsf{fma}\left(-0.25, th \cdot th, 0.5\right)\right) \cdot t\_2\\ \mathbf{else}:\\ \;\;\;\;\left(0.5 \cdot \sqrt{2}\right) \cdot t\_2\\ \end{array} \end{array} \]
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))) (t_2 (fma a1 a1 (* a2 a2))))
   (if (<= (+ (* t_1 (* a1 a1)) (* t_1 (* a2 a2))) -5e-274)
     (* (* (sqrt 2.0) (fma -0.25 (* th th) 0.5)) t_2)
     (* (* 0.5 (sqrt 2.0)) t_2))))
assert(a1 < a2 && a2 < th);
double code(double a1, double a2, double th) {
	double t_1 = cos(th) / sqrt(2.0);
	double t_2 = fma(a1, a1, (a2 * a2));
	double tmp;
	if (((t_1 * (a1 * a1)) + (t_1 * (a2 * a2))) <= -5e-274) {
		tmp = (sqrt(2.0) * fma(-0.25, (th * th), 0.5)) * t_2;
	} else {
		tmp = (0.5 * sqrt(2.0)) * t_2;
	}
	return tmp;
}
a1, a2, th = sort([a1, a2, th])
function code(a1, a2, th)
	t_1 = Float64(cos(th) / sqrt(2.0))
	t_2 = fma(a1, a1, Float64(a2 * a2))
	tmp = 0.0
	if (Float64(Float64(t_1 * Float64(a1 * a1)) + Float64(t_1 * Float64(a2 * a2))) <= -5e-274)
		tmp = Float64(Float64(sqrt(2.0) * fma(-0.25, Float64(th * th), 0.5)) * t_2);
	else
		tmp = Float64(Float64(0.5 * sqrt(2.0)) * t_2);
	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]}, Block[{t$95$2 = N[(a1 * a1 + N[(a2 * a2), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(t$95$1 * N[(a1 * a1), $MachinePrecision]), $MachinePrecision] + N[(t$95$1 * N[(a2 * a2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -5e-274], N[(N[(N[Sqrt[2.0], $MachinePrecision] * N[(-0.25 * N[(th * th), $MachinePrecision] + 0.5), $MachinePrecision]), $MachinePrecision] * t$95$2), $MachinePrecision], N[(N[(0.5 * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * t$95$2), $MachinePrecision]]]]
\begin{array}{l}
[a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
\\
\begin{array}{l}
t_1 := \frac{\cos th}{\sqrt{2}}\\
t_2 := \mathsf{fma}\left(a1, a1, a2 \cdot a2\right)\\
\mathbf{if}\;t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right) \leq -5 \cdot 10^{-274}:\\
\;\;\;\;\left(\sqrt{2} \cdot \mathsf{fma}\left(-0.25, th \cdot th, 0.5\right)\right) \cdot t\_2\\

\mathbf{else}:\\
\;\;\;\;\left(0.5 \cdot \sqrt{2}\right) \cdot t\_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))) < -5e-274

    1. Initial program 98.3%

      \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{2}\right)\right) + \left(\mathsf{neg}\left(\sqrt{2}\right)\right) \cdot \left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a1 \cdot a1\right)\right)}{\sqrt{2} \cdot \color{blue}{\sqrt{2}}} \]
      15. rem-square-sqrtN/A

        \[\leadsto \frac{\left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{2}\right)\right) + \left(\mathsf{neg}\left(\sqrt{2}\right)\right) \cdot \left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a1 \cdot a1\right)\right)}{\color{blue}{2}} \]
    4. Applied rewrites99.7%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(\left(\frac{1}{2} \cdot \sqrt{2}\right) \cdot \cos th\right) \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \]
      14. lower-*.f6498.2

        \[\leadsto \left(\left(0.5 \cdot \sqrt{2}\right) \cdot \cos th\right) \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \]
    7. Applied rewrites98.2%

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

      \[\leadsto \left(\frac{-1}{4} \cdot \left({th}^{2} \cdot \sqrt{2}\right) + \frac{1}{2} \cdot \sqrt{2}\right) \cdot \mathsf{fma}\left(\color{blue}{a1}, a1, a2 \cdot a2\right) \]
    9. Step-by-step derivation
      1. Applied rewrites58.5%

        \[\leadsto \left(\sqrt{2} \cdot \mathsf{fma}\left(-0.25, th \cdot th, 0.5\right)\right) \cdot \mathsf{fma}\left(\color{blue}{a1}, a1, a2 \cdot a2\right) \]

      if -5e-274 < (+.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 99.6%

        \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \frac{\left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{2}\right)\right) + \left(\mathsf{neg}\left(\sqrt{2}\right)\right) \cdot \left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a1 \cdot a1\right)\right)}{\sqrt{2} \cdot \color{blue}{\sqrt{2}}} \]
        15. rem-square-sqrtN/A

          \[\leadsto \frac{\left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{2}\right)\right) + \left(\mathsf{neg}\left(\sqrt{2}\right)\right) \cdot \left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a1 \cdot a1\right)\right)}{\color{blue}{2}} \]
      4. Applied rewrites99.7%

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

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

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

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

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

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

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

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

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

          \[\leadsto \left(\frac{1}{2} \cdot \sqrt{2}\right) \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \]
        9. lower-*.f6484.2

          \[\leadsto \left(0.5 \cdot \sqrt{2}\right) \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \]
      7. Applied rewrites84.2%

        \[\leadsto \color{blue}{\left(0.5 \cdot \sqrt{2}\right) \cdot \mathsf{fma}\left(a1, a1, a2 \cdot a2\right)} \]
    10. Recombined 2 regimes into one program.
    11. Add Preprocessing

    Alternative 4: 99.6% accurate, 1.0× speedup?

    \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \frac{\mathsf{fma}\left(a2 \cdot \cos th, a2 \cdot \sqrt{2}, \left(a1 \cdot \cos th\right) \cdot \left(a1 \cdot \sqrt{2}\right)\right)}{2} \end{array} \]
    NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
    (FPCore (a1 a2 th)
     :precision binary64
     (/
      (fma (* a2 (cos th)) (* a2 (sqrt 2.0)) (* (* a1 (cos th)) (* a1 (sqrt 2.0))))
      2.0))
    assert(a1 < a2 && a2 < th);
    double code(double a1, double a2, double th) {
    	return fma((a2 * cos(th)), (a2 * sqrt(2.0)), ((a1 * cos(th)) * (a1 * sqrt(2.0)))) / 2.0;
    }
    
    a1, a2, th = sort([a1, a2, th])
    function code(a1, a2, th)
    	return Float64(fma(Float64(a2 * cos(th)), Float64(a2 * sqrt(2.0)), Float64(Float64(a1 * cos(th)) * Float64(a1 * sqrt(2.0)))) / 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 * N[Cos[th], $MachinePrecision]), $MachinePrecision] * N[(a2 * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] + N[(N[(a1 * N[Cos[th], $MachinePrecision]), $MachinePrecision] * N[(a1 * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision]
    
    \begin{array}{l}
    [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
    \\
    \frac{\mathsf{fma}\left(a2 \cdot \cos th, a2 \cdot \sqrt{2}, \left(a1 \cdot \cos th\right) \cdot \left(a1 \cdot \sqrt{2}\right)\right)}{2}
    \end{array}
    
    Derivation
    1. Initial program 99.3%

      \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    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

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

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

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

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

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

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

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

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

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

        \[\leadsto \color{blue}{\frac{\left(\cos th \cdot \left(a1 \cdot a1\right)\right) \cdot \sqrt{2} + \sqrt{2} \cdot \left(\cos th \cdot \left(a2 \cdot a2\right)\right)}{2}} \]
    4. Applied rewrites99.7%

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

    Alternative 5: 99.6% accurate, 1.1× speedup?

    \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \frac{\mathsf{fma}\left(\cos th \cdot a2, a2, \left(a1 \cdot \cos th\right) \cdot a1\right)}{\sqrt{2}} \end{array} \]
    NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
    (FPCore (a1 a2 th)
     :precision binary64
     (/ (fma (* (cos th) a2) a2 (* (* a1 (cos th)) a1)) (sqrt 2.0)))
    assert(a1 < a2 && a2 < th);
    double code(double a1, double a2, double th) {
    	return fma((cos(th) * a2), a2, ((a1 * cos(th)) * a1)) / sqrt(2.0);
    }
    
    a1, a2, th = sort([a1, a2, th])
    function code(a1, a2, th)
    	return Float64(fma(Float64(cos(th) * a2), a2, Float64(Float64(a1 * cos(th)) * 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[(N[(N[Cos[th], $MachinePrecision] * a2), $MachinePrecision] * a2 + N[(N[(a1 * N[Cos[th], $MachinePrecision]), $MachinePrecision] * a1), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
    \\
    \frac{\mathsf{fma}\left(\cos th \cdot a2, a2, \left(a1 \cdot \cos th\right) \cdot a1\right)}{\sqrt{2}}
    \end{array}
    
    Derivation
    1. Initial program 99.3%

      \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{2}\right)\right) + \left(\mathsf{neg}\left(\sqrt{2}\right)\right) \cdot \left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a1 \cdot a1\right)\right)}{\sqrt{2} \cdot \color{blue}{\sqrt{2}}} \]
      15. rem-square-sqrtN/A

        \[\leadsto \frac{\left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{2}\right)\right) + \left(\mathsf{neg}\left(\sqrt{2}\right)\right) \cdot \left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a1 \cdot a1\right)\right)}{\color{blue}{2}} \]
    4. Applied rewrites99.7%

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

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

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

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

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

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

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

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

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

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

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

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

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

    Alternative 6: 99.6% accurate, 1.9× speedup?

    \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \left(\mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \cdot \left(\sqrt{2} \cdot 0.5\right)\right) \cdot \cos th \end{array} \]
    NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
    (FPCore (a1 a2 th)
     :precision binary64
     (* (* (fma a1 a1 (* a2 a2)) (* (sqrt 2.0) 0.5)) (cos th)))
    assert(a1 < a2 && a2 < th);
    double code(double a1, double a2, double th) {
    	return (fma(a1, a1, (a2 * a2)) * (sqrt(2.0) * 0.5)) * cos(th);
    }
    
    a1, a2, th = sort([a1, a2, th])
    function code(a1, a2, th)
    	return Float64(Float64(fma(a1, a1, Float64(a2 * a2)) * Float64(sqrt(2.0) * 0.5)) * 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[(a1 * a1 + N[(a2 * a2), $MachinePrecision]), $MachinePrecision] * N[(N[Sqrt[2.0], $MachinePrecision] * 0.5), $MachinePrecision]), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
    \\
    \left(\mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \cdot \left(\sqrt{2} \cdot 0.5\right)\right) \cdot \cos th
    \end{array}
    
    Derivation
    1. Initial program 99.3%

      \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{2}\right)\right) + \left(\mathsf{neg}\left(\sqrt{2}\right)\right) \cdot \left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a1 \cdot a1\right)\right)}{\sqrt{2} \cdot \color{blue}{\sqrt{2}}} \]
      15. rem-square-sqrtN/A

        \[\leadsto \frac{\left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{2}\right)\right) + \left(\mathsf{neg}\left(\sqrt{2}\right)\right) \cdot \left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a1 \cdot a1\right)\right)}{\color{blue}{2}} \]
    4. Applied rewrites99.7%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(\left(\frac{1}{2} \cdot \sqrt{2}\right) \cdot \cos th\right) \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \]
      14. lower-*.f6499.3

        \[\leadsto \left(\left(0.5 \cdot \sqrt{2}\right) \cdot \cos th\right) \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \]
    7. Applied rewrites99.3%

      \[\leadsto \color{blue}{\left(\left(0.5 \cdot \sqrt{2}\right) \cdot \cos th\right) \cdot \mathsf{fma}\left(a1, a1, a2 \cdot a2\right)} \]
    8. Step-by-step derivation
      1. Applied rewrites99.3%

        \[\leadsto \left(\mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \cdot \left(\sqrt{2} \cdot 0.5\right)\right) \cdot \color{blue}{\cos th} \]
      2. Add Preprocessing

      Alternative 7: 99.6% accurate, 1.9× speedup?

      \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \left(\left(0.5 \cdot \sqrt{2}\right) \cdot \cos th\right) \cdot \mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \end{array} \]
      NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
      (FPCore (a1 a2 th)
       :precision binary64
       (* (* (* 0.5 (sqrt 2.0)) (cos th)) (fma a1 a1 (* a2 a2))))
      assert(a1 < a2 && a2 < th);
      double code(double a1, double a2, double th) {
      	return ((0.5 * sqrt(2.0)) * cos(th)) * fma(a1, a1, (a2 * a2));
      }
      
      a1, a2, th = sort([a1, a2, th])
      function code(a1, a2, th)
      	return Float64(Float64(Float64(0.5 * sqrt(2.0)) * cos(th)) * 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[(N[(0.5 * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision] * N[(a1 * a1 + N[(a2 * a2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
      \\
      \left(\left(0.5 \cdot \sqrt{2}\right) \cdot \cos th\right) \cdot \mathsf{fma}\left(a1, a1, a2 \cdot a2\right)
      \end{array}
      
      Derivation
      1. Initial program 99.3%

        \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \frac{\left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{2}\right)\right) + \left(\mathsf{neg}\left(\sqrt{2}\right)\right) \cdot \left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a1 \cdot a1\right)\right)}{\sqrt{2} \cdot \color{blue}{\sqrt{2}}} \]
        15. rem-square-sqrtN/A

          \[\leadsto \frac{\left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{2}\right)\right) + \left(\mathsf{neg}\left(\sqrt{2}\right)\right) \cdot \left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a1 \cdot a1\right)\right)}{\color{blue}{2}} \]
      4. Applied rewrites99.7%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \left(\left(\frac{1}{2} \cdot \sqrt{2}\right) \cdot \cos th\right) \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \]
        14. lower-*.f6499.3

          \[\leadsto \left(\left(0.5 \cdot \sqrt{2}\right) \cdot \cos th\right) \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \]
      7. Applied rewrites99.3%

        \[\leadsto \color{blue}{\left(\left(0.5 \cdot \sqrt{2}\right) \cdot \cos th\right) \cdot \mathsf{fma}\left(a1, a1, a2 \cdot a2\right)} \]
      8. Add Preprocessing

      Alternative 8: 57.2% accurate, 2.0× speedup?

      \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \left(\cos th \cdot a2\right) \cdot \frac{a2}{\sqrt{2}} \end{array} \]
      NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
      (FPCore (a1 a2 th) :precision binary64 (* (* (cos th) a2) (/ a2 (sqrt 2.0))))
      assert(a1 < a2 && a2 < th);
      double code(double a1, double a2, double th) {
      	return (cos(th) * a2) * (a2 / sqrt(2.0));
      }
      
      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 = (cos(th) * a2) * (a2 / sqrt(2.0d0))
      end function
      
      assert a1 < a2 && a2 < th;
      public static double code(double a1, double a2, double th) {
      	return (Math.cos(th) * a2) * (a2 / Math.sqrt(2.0));
      }
      
      [a1, a2, th] = sort([a1, a2, th])
      def code(a1, a2, th):
      	return (math.cos(th) * a2) * (a2 / math.sqrt(2.0))
      
      a1, a2, th = sort([a1, a2, th])
      function code(a1, a2, th)
      	return Float64(Float64(cos(th) * a2) * Float64(a2 / sqrt(2.0)))
      end
      
      a1, a2, th = num2cell(sort([a1, a2, th])){:}
      function tmp = code(a1, a2, th)
      	tmp = (cos(th) * a2) * (a2 / 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[Cos[th], $MachinePrecision] * a2), $MachinePrecision] * N[(a2 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
      \\
      \left(\cos th \cdot a2\right) \cdot \frac{a2}{\sqrt{2}}
      \end{array}
      
      Derivation
      1. Initial program 99.3%

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

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

          \[\leadsto \frac{\color{blue}{\cos th \cdot {a2}^{2}}}{\sqrt{2}} \]
        2. unpow2N/A

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

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

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

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

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

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

          \[\leadsto \left(\cos th \cdot a2\right) \cdot \color{blue}{\frac{a2}{\sqrt{2}}} \]
        9. lower-sqrt.f6458.2

          \[\leadsto \left(\cos th \cdot a2\right) \cdot \frac{a2}{\color{blue}{\sqrt{2}}} \]
      5. Applied rewrites58.2%

        \[\leadsto \color{blue}{\left(\cos th \cdot a2\right) \cdot \frac{a2}{\sqrt{2}}} \]
      6. Add Preprocessing

      Alternative 9: 57.2% accurate, 2.0× speedup?

      \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \left(0.5 \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\sqrt{2} \cdot \cos th\right) \end{array} \]
      NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
      (FPCore (a1 a2 th)
       :precision binary64
       (* (* 0.5 (* a2 a2)) (* (sqrt 2.0) (cos th))))
      assert(a1 < a2 && a2 < th);
      double code(double a1, double a2, double th) {
      	return (0.5 * (a2 * a2)) * (sqrt(2.0) * cos(th));
      }
      
      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 = (0.5d0 * (a2 * a2)) * (sqrt(2.0d0) * cos(th))
      end function
      
      assert a1 < a2 && a2 < th;
      public static double code(double a1, double a2, double th) {
      	return (0.5 * (a2 * a2)) * (Math.sqrt(2.0) * Math.cos(th));
      }
      
      [a1, a2, th] = sort([a1, a2, th])
      def code(a1, a2, th):
      	return (0.5 * (a2 * a2)) * (math.sqrt(2.0) * math.cos(th))
      
      a1, a2, th = sort([a1, a2, th])
      function code(a1, a2, th)
      	return Float64(Float64(0.5 * Float64(a2 * a2)) * Float64(sqrt(2.0) * cos(th)))
      end
      
      a1, a2, th = num2cell(sort([a1, a2, th])){:}
      function tmp = code(a1, a2, th)
      	tmp = (0.5 * (a2 * a2)) * (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[(0.5 * N[(a2 * a2), $MachinePrecision]), $MachinePrecision] * N[(N[Sqrt[2.0], $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
      \\
      \left(0.5 \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\sqrt{2} \cdot \cos th\right)
      \end{array}
      
      Derivation
      1. Initial program 99.3%

        \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \frac{\left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{2}\right)\right) + \left(\mathsf{neg}\left(\sqrt{2}\right)\right) \cdot \left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a1 \cdot a1\right)\right)}{\sqrt{2} \cdot \color{blue}{\sqrt{2}}} \]
        15. rem-square-sqrtN/A

          \[\leadsto \frac{\left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{2}\right)\right) + \left(\mathsf{neg}\left(\sqrt{2}\right)\right) \cdot \left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a1 \cdot a1\right)\right)}{\color{blue}{2}} \]
      4. Applied rewrites99.7%

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

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

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

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

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

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

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

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

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

          \[\leadsto \left(\frac{1}{2} \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\color{blue}{\sqrt{2}} \cdot \cos th\right) \]
        9. lower-cos.f6457.9

          \[\leadsto \left(0.5 \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\sqrt{2} \cdot \color{blue}{\cos th}\right) \]
      7. Applied rewrites57.9%

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

      Alternative 10: 65.9% accurate, 8.3× speedup?

      \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \left(0.5 \cdot \sqrt{2}\right) \cdot \mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \end{array} \]
      NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
      (FPCore (a1 a2 th)
       :precision binary64
       (* (* 0.5 (sqrt 2.0)) (fma a1 a1 (* a2 a2))))
      assert(a1 < a2 && a2 < th);
      double code(double a1, double a2, double th) {
      	return (0.5 * sqrt(2.0)) * fma(a1, a1, (a2 * a2));
      }
      
      a1, a2, th = sort([a1, a2, th])
      function code(a1, a2, th)
      	return Float64(Float64(0.5 * sqrt(2.0)) * 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[(0.5 * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[(a1 * a1 + N[(a2 * a2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
      \\
      \left(0.5 \cdot \sqrt{2}\right) \cdot \mathsf{fma}\left(a1, a1, a2 \cdot a2\right)
      \end{array}
      
      Derivation
      1. Initial program 99.3%

        \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \frac{\left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{2}\right)\right) + \left(\mathsf{neg}\left(\sqrt{2}\right)\right) \cdot \left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a1 \cdot a1\right)\right)}{\sqrt{2} \cdot \color{blue}{\sqrt{2}}} \]
        15. rem-square-sqrtN/A

          \[\leadsto \frac{\left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \left(\mathsf{neg}\left(\sqrt{2}\right)\right) + \left(\mathsf{neg}\left(\sqrt{2}\right)\right) \cdot \left(\left(\mathsf{neg}\left(\cos th\right)\right) \cdot \left(a1 \cdot a1\right)\right)}{\color{blue}{2}} \]
      4. Applied rewrites99.7%

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

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

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

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

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

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

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

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

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

          \[\leadsto \left(\frac{1}{2} \cdot \sqrt{2}\right) \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \]
        9. lower-*.f6464.3

          \[\leadsto \left(0.5 \cdot \sqrt{2}\right) \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \]
      7. Applied rewrites64.3%

        \[\leadsto \color{blue}{\left(0.5 \cdot \sqrt{2}\right) \cdot \mathsf{fma}\left(a1, a1, a2 \cdot a2\right)} \]
      8. Add Preprocessing

      Alternative 11: 39.6% accurate, 9.9× speedup?

      \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ \frac{a2 \cdot a2}{\sqrt{2}} \end{array} \]
      NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
      (FPCore (a1 a2 th) :precision binary64 (/ (* a2 a2) (sqrt 2.0)))
      assert(a1 < a2 && a2 < th);
      double code(double a1, double a2, double th) {
      	return (a2 * a2) / sqrt(2.0);
      }
      
      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) / sqrt(2.0d0)
      end function
      
      assert a1 < a2 && a2 < th;
      public static double code(double a1, double a2, double th) {
      	return (a2 * a2) / Math.sqrt(2.0);
      }
      
      [a1, a2, th] = sort([a1, a2, th])
      def code(a1, a2, th):
      	return (a2 * a2) / math.sqrt(2.0)
      
      a1, a2, th = sort([a1, a2, th])
      function code(a1, a2, th)
      	return Float64(Float64(a2 * a2) / sqrt(2.0))
      end
      
      a1, a2, th = num2cell(sort([a1, a2, th])){:}
      function tmp = code(a1, a2, th)
      	tmp = (a2 * a2) / 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), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
      \\
      \frac{a2 \cdot a2}{\sqrt{2}}
      \end{array}
      
      Derivation
      1. Initial program 99.3%

        \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      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. div-add-revN/A

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

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

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

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

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

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

          \[\leadsto \frac{\mathsf{fma}\left(a2, a2, \color{blue}{a1 \cdot a1}\right)}{\sqrt{2}} \]
        8. lower-sqrt.f6464.3

          \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
      5. Applied rewrites64.3%

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

        \[\leadsto \frac{{a2}^{2}}{\sqrt{\color{blue}{2}}} \]
      7. Step-by-step derivation
        1. Applied rewrites41.9%

          \[\leadsto \frac{a2 \cdot a2}{\sqrt{\color{blue}{2}}} \]
        2. Add Preprocessing

        Alternative 12: 39.6% accurate, 9.9× speedup?

        \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ a2 \cdot \frac{a2}{\sqrt{2}} \end{array} \]
        NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
        (FPCore (a1 a2 th) :precision binary64 (* a2 (/ a2 (sqrt 2.0))))
        assert(a1 < a2 && a2 < th);
        double code(double a1, double a2, double th) {
        	return a2 * (a2 / sqrt(2.0));
        }
        
        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 / sqrt(2.0d0))
        end function
        
        assert a1 < a2 && a2 < th;
        public static double code(double a1, double a2, double th) {
        	return a2 * (a2 / Math.sqrt(2.0));
        }
        
        [a1, a2, th] = sort([a1, a2, th])
        def code(a1, a2, th):
        	return a2 * (a2 / math.sqrt(2.0))
        
        a1, a2, th = sort([a1, a2, th])
        function code(a1, a2, th)
        	return Float64(a2 * Float64(a2 / sqrt(2.0)))
        end
        
        a1, a2, th = num2cell(sort([a1, a2, th])){:}
        function tmp = code(a1, a2, th)
        	tmp = a2 * (a2 / sqrt(2.0));
        end
        
        NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
        code[a1_, a2_, th_] := N[(a2 * N[(a2 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
        
        \begin{array}{l}
        [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
        \\
        a2 \cdot \frac{a2}{\sqrt{2}}
        \end{array}
        
        Derivation
        1. Initial program 99.3%

          \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
        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. div-add-revN/A

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

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

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

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

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

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

            \[\leadsto \frac{\mathsf{fma}\left(a2, a2, \color{blue}{a1 \cdot a1}\right)}{\sqrt{2}} \]
          8. lower-sqrt.f6464.3

            \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
        5. Applied rewrites64.3%

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

          \[\leadsto \frac{{a2}^{2}}{\color{blue}{\sqrt{2}}} \]
        7. Step-by-step derivation
          1. Applied rewrites41.9%

            \[\leadsto a2 \cdot \color{blue}{\frac{a2}{\sqrt{2}}} \]
          2. Add Preprocessing

          Alternative 13: 39.4% accurate, 9.9× speedup?

          \[\begin{array}{l} [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\ \\ a1 \cdot \frac{a1}{\sqrt{2}} \end{array} \]
          NOTE: a1, a2, and th should be sorted in increasing order before calling this function.
          (FPCore (a1 a2 th) :precision binary64 (* a1 (/ a1 (sqrt 2.0))))
          assert(a1 < a2 && a2 < th);
          double code(double a1, double a2, double th) {
          	return a1 * (a1 / sqrt(2.0));
          }
          
          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 = a1 * (a1 / sqrt(2.0d0))
          end function
          
          assert a1 < a2 && a2 < th;
          public static double code(double a1, double a2, double th) {
          	return a1 * (a1 / Math.sqrt(2.0));
          }
          
          [a1, a2, th] = sort([a1, a2, th])
          def code(a1, a2, th):
          	return a1 * (a1 / math.sqrt(2.0))
          
          a1, a2, th = sort([a1, a2, th])
          function code(a1, a2, th)
          	return Float64(a1 * Float64(a1 / sqrt(2.0)))
          end
          
          a1, a2, th = num2cell(sort([a1, a2, th])){:}
          function tmp = code(a1, a2, th)
          	tmp = 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[(a1 * N[(a1 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
          
          \begin{array}{l}
          [a1, a2, th] = \mathsf{sort}([a1, a2, th])\\
          \\
          a1 \cdot \frac{a1}{\sqrt{2}}
          \end{array}
          
          Derivation
          1. Initial program 99.3%

            \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
          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. div-add-revN/A

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

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

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

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

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

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

              \[\leadsto \frac{\mathsf{fma}\left(a2, a2, \color{blue}{a1 \cdot a1}\right)}{\sqrt{2}} \]
            8. lower-sqrt.f6464.3

              \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
          5. Applied rewrites64.3%

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

            \[\leadsto \frac{{a1}^{2}}{\color{blue}{\sqrt{2}}} \]
          7. Step-by-step derivation
            1. Applied rewrites39.4%

              \[\leadsto a1 \cdot \color{blue}{\frac{a1}{\sqrt{2}}} \]
            2. Add Preprocessing

            Reproduce

            ?
            herbie shell --seed 2024332 
            (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))))