Migdal et al, Equation (64)

Percentage Accurate: 99.5% → 99.5%
Time: 11.4s
Alternatives: 16
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 16 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: 99.5% accurate, 1.9× speedup?

\[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \frac{\cos th}{\sqrt{2}} \cdot \mathsf{fma}\left(a2, a2, a1\_m \cdot a1\_m\right) \end{array} \]
a1_m = (fabs.f64 a1)
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
(FPCore (a1_m a2 th)
 :precision binary64
 (* (/ (cos th) (sqrt 2.0)) (fma a2 a2 (* a1_m a1_m))))
a1_m = fabs(a1);
assert(a1_m < a2 && a2 < th);
double code(double a1_m, double a2, double th) {
	return (cos(th) / sqrt(2.0)) * fma(a2, a2, (a1_m * a1_m));
}
a1_m = abs(a1)
a1_m, a2, th = sort([a1_m, a2, th])
function code(a1_m, a2, th)
	return Float64(Float64(cos(th) / sqrt(2.0)) * fma(a2, a2, Float64(a1_m * a1_m)))
end
a1_m = N[Abs[a1], $MachinePrecision]
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
code[a1$95$m_, a2_, th_] := N[(N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[(a2 * a2 + N[(a1$95$m * a1$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
a1_m = \left|a1\right|
\\
[a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
\\
\frac{\cos th}{\sqrt{2}} \cdot \mathsf{fma}\left(a2, a2, a1\_m \cdot a1\_m\right)
\end{array}
Derivation
  1. Initial program 99.7%

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

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

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

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

      \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
    5. *-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.f6499.7

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

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

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

Alternative 2: 77.5% accurate, 0.8× speedup?

\[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \begin{array}{l} t_1 := \frac{\cos th}{\sqrt{2}}\\ \mathbf{if}\;\left(a2 \cdot a2\right) \cdot t\_1 + t\_1 \cdot \left(a1\_m \cdot a1\_m\right) \leq -5 \cdot 10^{-122}:\\ \;\;\;\;\left(\left(\left(\mathsf{fma}\left(a1\_m, a1\_m, a2 \cdot a2\right) \cdot th\right) \cdot th\right) \cdot \left(-0.5 \cdot \sqrt{2}\right)\right) \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(a2, a2, a1\_m \cdot a1\_m\right)}{\sqrt{2}}\\ \end{array} \end{array} \]
a1_m = (fabs.f64 a1)
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
(FPCore (a1_m a2 th)
 :precision binary64
 (let* ((t_1 (/ (cos th) (sqrt 2.0))))
   (if (<= (+ (* (* a2 a2) t_1) (* t_1 (* a1_m a1_m))) -5e-122)
     (* (* (* (* (fma a1_m a1_m (* a2 a2)) th) th) (* -0.5 (sqrt 2.0))) 0.5)
     (/ (fma a2 a2 (* a1_m a1_m)) (sqrt 2.0)))))
a1_m = fabs(a1);
assert(a1_m < a2 && a2 < th);
double code(double a1_m, double a2, double th) {
	double t_1 = cos(th) / sqrt(2.0);
	double tmp;
	if ((((a2 * a2) * t_1) + (t_1 * (a1_m * a1_m))) <= -5e-122) {
		tmp = (((fma(a1_m, a1_m, (a2 * a2)) * th) * th) * (-0.5 * sqrt(2.0))) * 0.5;
	} else {
		tmp = fma(a2, a2, (a1_m * a1_m)) / sqrt(2.0);
	}
	return tmp;
}
a1_m = abs(a1)
a1_m, a2, th = sort([a1_m, a2, th])
function code(a1_m, a2, th)
	t_1 = Float64(cos(th) / sqrt(2.0))
	tmp = 0.0
	if (Float64(Float64(Float64(a2 * a2) * t_1) + Float64(t_1 * Float64(a1_m * a1_m))) <= -5e-122)
		tmp = Float64(Float64(Float64(Float64(fma(a1_m, a1_m, Float64(a2 * a2)) * th) * th) * Float64(-0.5 * sqrt(2.0))) * 0.5);
	else
		tmp = Float64(fma(a2, a2, Float64(a1_m * a1_m)) / sqrt(2.0));
	end
	return tmp
end
a1_m = N[Abs[a1], $MachinePrecision]
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
code[a1$95$m_, a2_, th_] := Block[{t$95$1 = N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(N[(a2 * a2), $MachinePrecision] * t$95$1), $MachinePrecision] + N[(t$95$1 * N[(a1$95$m * a1$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -5e-122], N[(N[(N[(N[(N[(a1$95$m * a1$95$m + N[(a2 * a2), $MachinePrecision]), $MachinePrecision] * th), $MachinePrecision] * th), $MachinePrecision] * N[(-0.5 * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision], N[(N[(a2 * a2 + N[(a1$95$m * a1$95$m), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
a1_m = \left|a1\right|
\\
[a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
\\
\begin{array}{l}
t_1 := \frac{\cos th}{\sqrt{2}}\\
\mathbf{if}\;\left(a2 \cdot a2\right) \cdot t\_1 + t\_1 \cdot \left(a1\_m \cdot a1\_m\right) \leq -5 \cdot 10^{-122}:\\
\;\;\;\;\left(\left(\left(\mathsf{fma}\left(a1\_m, a1\_m, a2 \cdot a2\right) \cdot th\right) \cdot th\right) \cdot \left(-0.5 \cdot \sqrt{2}\right)\right) \cdot 0.5\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a1 a1)) (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a2 a2))) < -4.9999999999999999e-122

    1. Initial program 99.7%

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

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

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

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

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

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

        \[\leadsto \color{blue}{\left(\left(\cos th \cdot \left(a1 \cdot a1\right)\right) \cdot \sqrt{2} + \sqrt{2} \cdot \left(\cos th \cdot \left(a2 \cdot a2\right)\right)\right) \cdot \frac{1}{2}} \]
    4. Applied rewrites99.6%

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

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

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

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

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

        \[\leadsto \left(\left({a1}^{2} \cdot \sqrt{2} + {a2}^{2} \cdot \sqrt{2}\right) + \color{blue}{\left(\frac{-1}{2} \cdot {th}^{2}\right)} \cdot \left({a1}^{2} \cdot \sqrt{2} + {a2}^{2} \cdot \sqrt{2}\right)\right) \cdot \frac{1}{2} \]
      5. distribute-rgt1-inN/A

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

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

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

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

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

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

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

        \[\leadsto \left(\mathsf{fma}\left(\color{blue}{th \cdot th}, \frac{-1}{2}, 1\right) \cdot \left({a1}^{2} \cdot \sqrt{2} + {a2}^{2} \cdot \sqrt{2}\right)\right) \cdot \frac{1}{2} \]
    7. Applied rewrites43.7%

      \[\leadsto \color{blue}{\left(\mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot \left(\mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \cdot \sqrt{2}\right)\right)} \cdot 0.5 \]
    8. Taylor expanded in th around inf

      \[\leadsto \left(\frac{-1}{2} \cdot \color{blue}{\left({th}^{2} \cdot \left(\sqrt{2} \cdot \left({a1}^{2} + {a2}^{2}\right)\right)\right)}\right) \cdot \frac{1}{2} \]
    9. Step-by-step derivation
      1. Applied rewrites43.7%

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

      if -4.9999999999999999e-122 < (+.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 99.7%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
      6. Step-by-step derivation
        1. lower-sqrt.f6482.4

          \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
      7. Applied rewrites82.4%

        \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
    10. Recombined 2 regimes into one program.
    11. Final simplification75.6%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\left(a2 \cdot a2\right) \cdot \frac{\cos th}{\sqrt{2}} + \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) \leq -5 \cdot 10^{-122}:\\ \;\;\;\;\left(\left(\left(\mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \cdot th\right) \cdot th\right) \cdot \left(-0.5 \cdot \sqrt{2}\right)\right) \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}}\\ \end{array} \]
    12. Add Preprocessing

    Alternative 3: 76.1% accurate, 0.8× speedup?

    \[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \begin{array}{l} t_1 := \frac{\cos th}{\sqrt{2}}\\ \mathbf{if}\;\left(a2 \cdot a2\right) \cdot t\_1 + t\_1 \cdot \left(a1\_m \cdot a1\_m\right) \leq -5 \cdot 10^{-122}:\\ \;\;\;\;\left(\left(\mathsf{fma}\left(-0.5, th \cdot th, 1\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \sqrt{2}\right) \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(a2, a2, a1\_m \cdot a1\_m\right)}{\sqrt{2}}\\ \end{array} \end{array} \]
    a1_m = (fabs.f64 a1)
    NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
    (FPCore (a1_m a2 th)
     :precision binary64
     (let* ((t_1 (/ (cos th) (sqrt 2.0))))
       (if (<= (+ (* (* a2 a2) t_1) (* t_1 (* a1_m a1_m))) -5e-122)
         (* (* (* (fma -0.5 (* th th) 1.0) (* a2 a2)) (sqrt 2.0)) 0.5)
         (/ (fma a2 a2 (* a1_m a1_m)) (sqrt 2.0)))))
    a1_m = fabs(a1);
    assert(a1_m < a2 && a2 < th);
    double code(double a1_m, double a2, double th) {
    	double t_1 = cos(th) / sqrt(2.0);
    	double tmp;
    	if ((((a2 * a2) * t_1) + (t_1 * (a1_m * a1_m))) <= -5e-122) {
    		tmp = ((fma(-0.5, (th * th), 1.0) * (a2 * a2)) * sqrt(2.0)) * 0.5;
    	} else {
    		tmp = fma(a2, a2, (a1_m * a1_m)) / sqrt(2.0);
    	}
    	return tmp;
    }
    
    a1_m = abs(a1)
    a1_m, a2, th = sort([a1_m, a2, th])
    function code(a1_m, a2, th)
    	t_1 = Float64(cos(th) / sqrt(2.0))
    	tmp = 0.0
    	if (Float64(Float64(Float64(a2 * a2) * t_1) + Float64(t_1 * Float64(a1_m * a1_m))) <= -5e-122)
    		tmp = Float64(Float64(Float64(fma(-0.5, Float64(th * th), 1.0) * Float64(a2 * a2)) * sqrt(2.0)) * 0.5);
    	else
    		tmp = Float64(fma(a2, a2, Float64(a1_m * a1_m)) / sqrt(2.0));
    	end
    	return tmp
    end
    
    a1_m = N[Abs[a1], $MachinePrecision]
    NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
    code[a1$95$m_, a2_, th_] := Block[{t$95$1 = N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(N[(a2 * a2), $MachinePrecision] * t$95$1), $MachinePrecision] + N[(t$95$1 * N[(a1$95$m * a1$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -5e-122], N[(N[(N[(N[(-0.5 * N[(th * th), $MachinePrecision] + 1.0), $MachinePrecision] * N[(a2 * a2), $MachinePrecision]), $MachinePrecision] * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision], N[(N[(a2 * a2 + N[(a1$95$m * a1$95$m), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]]]
    
    \begin{array}{l}
    a1_m = \left|a1\right|
    \\
    [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
    \\
    \begin{array}{l}
    t_1 := \frac{\cos th}{\sqrt{2}}\\
    \mathbf{if}\;\left(a2 \cdot a2\right) \cdot t\_1 + t\_1 \cdot \left(a1\_m \cdot a1\_m\right) \leq -5 \cdot 10^{-122}:\\
    \;\;\;\;\left(\left(\mathsf{fma}\left(-0.5, th \cdot th, 1\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \sqrt{2}\right) \cdot 0.5\\
    
    \mathbf{else}:\\
    \;\;\;\;\frac{\mathsf{fma}\left(a2, a2, a1\_m \cdot a1\_m\right)}{\sqrt{2}}\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (+.f64 (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a1 a1)) (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a2 a2))) < -4.9999999999999999e-122

      1. Initial program 99.7%

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

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

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

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

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

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

          \[\leadsto \color{blue}{\left(\left(\cos th \cdot \left(a1 \cdot a1\right)\right) \cdot \sqrt{2} + \sqrt{2} \cdot \left(\cos th \cdot \left(a2 \cdot a2\right)\right)\right) \cdot \frac{1}{2}} \]
      4. Applied rewrites99.6%

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

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

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

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

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

          \[\leadsto \left(\left({a1}^{2} \cdot \sqrt{2} + {a2}^{2} \cdot \sqrt{2}\right) + \color{blue}{\left(\frac{-1}{2} \cdot {th}^{2}\right)} \cdot \left({a1}^{2} \cdot \sqrt{2} + {a2}^{2} \cdot \sqrt{2}\right)\right) \cdot \frac{1}{2} \]
        5. distribute-rgt1-inN/A

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

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

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

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

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

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

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

          \[\leadsto \left(\mathsf{fma}\left(\color{blue}{th \cdot th}, \frac{-1}{2}, 1\right) \cdot \left({a1}^{2} \cdot \sqrt{2} + {a2}^{2} \cdot \sqrt{2}\right)\right) \cdot \frac{1}{2} \]
      7. Applied rewrites43.7%

        \[\leadsto \color{blue}{\left(\mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot \left(\mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \cdot \sqrt{2}\right)\right)} \cdot 0.5 \]
      8. Taylor expanded in a1 around 0

        \[\leadsto \left(\mathsf{fma}\left(th \cdot th, \frac{-1}{2}, 1\right) \cdot \left({a2}^{2} \cdot \sqrt{\color{blue}{2}}\right)\right) \cdot \frac{1}{2} \]
      9. Step-by-step derivation
        1. Applied rewrites34.1%

          \[\leadsto \left(\mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot \left(\left(a2 \cdot a2\right) \cdot \sqrt{\color{blue}{2}}\right)\right) \cdot 0.5 \]
        2. Step-by-step derivation
          1. Applied rewrites34.1%

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

          if -4.9999999999999999e-122 < (+.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 99.7%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
          6. Step-by-step derivation
            1. lower-sqrt.f6482.4

              \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
          7. Applied rewrites82.4%

            \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
        3. Recombined 2 regimes into one program.
        4. Final simplification73.9%

          \[\leadsto \begin{array}{l} \mathbf{if}\;\left(a2 \cdot a2\right) \cdot \frac{\cos th}{\sqrt{2}} + \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) \leq -5 \cdot 10^{-122}:\\ \;\;\;\;\left(\left(\mathsf{fma}\left(-0.5, th \cdot th, 1\right) \cdot \left(a2 \cdot a2\right)\right) \cdot \sqrt{2}\right) \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}}\\ \end{array} \]
        5. Add Preprocessing

        Alternative 4: 76.1% accurate, 0.9× speedup?

        \[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \begin{array}{l} t_1 := \frac{\cos th}{\sqrt{2}}\\ \mathbf{if}\;\left(a2 \cdot a2\right) \cdot t\_1 + t\_1 \cdot \left(a1\_m \cdot a1\_m\right) \leq -5 \cdot 10^{-122}:\\ \;\;\;\;\left(\left(\left(a2 \cdot a2\right) \cdot \sqrt{2}\right) \cdot \left(\left(th \cdot th\right) \cdot -0.5\right)\right) \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(a2, a2, a1\_m \cdot a1\_m\right)}{\sqrt{2}}\\ \end{array} \end{array} \]
        a1_m = (fabs.f64 a1)
        NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
        (FPCore (a1_m a2 th)
         :precision binary64
         (let* ((t_1 (/ (cos th) (sqrt 2.0))))
           (if (<= (+ (* (* a2 a2) t_1) (* t_1 (* a1_m a1_m))) -5e-122)
             (* (* (* (* a2 a2) (sqrt 2.0)) (* (* th th) -0.5)) 0.5)
             (/ (fma a2 a2 (* a1_m a1_m)) (sqrt 2.0)))))
        a1_m = fabs(a1);
        assert(a1_m < a2 && a2 < th);
        double code(double a1_m, double a2, double th) {
        	double t_1 = cos(th) / sqrt(2.0);
        	double tmp;
        	if ((((a2 * a2) * t_1) + (t_1 * (a1_m * a1_m))) <= -5e-122) {
        		tmp = (((a2 * a2) * sqrt(2.0)) * ((th * th) * -0.5)) * 0.5;
        	} else {
        		tmp = fma(a2, a2, (a1_m * a1_m)) / sqrt(2.0);
        	}
        	return tmp;
        }
        
        a1_m = abs(a1)
        a1_m, a2, th = sort([a1_m, a2, th])
        function code(a1_m, a2, th)
        	t_1 = Float64(cos(th) / sqrt(2.0))
        	tmp = 0.0
        	if (Float64(Float64(Float64(a2 * a2) * t_1) + Float64(t_1 * Float64(a1_m * a1_m))) <= -5e-122)
        		tmp = Float64(Float64(Float64(Float64(a2 * a2) * sqrt(2.0)) * Float64(Float64(th * th) * -0.5)) * 0.5);
        	else
        		tmp = Float64(fma(a2, a2, Float64(a1_m * a1_m)) / sqrt(2.0));
        	end
        	return tmp
        end
        
        a1_m = N[Abs[a1], $MachinePrecision]
        NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
        code[a1$95$m_, a2_, th_] := Block[{t$95$1 = N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(N[(a2 * a2), $MachinePrecision] * t$95$1), $MachinePrecision] + N[(t$95$1 * N[(a1$95$m * a1$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -5e-122], N[(N[(N[(N[(a2 * a2), $MachinePrecision] * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[(N[(th * th), $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision], N[(N[(a2 * a2 + N[(a1$95$m * a1$95$m), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]]]
        
        \begin{array}{l}
        a1_m = \left|a1\right|
        \\
        [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
        \\
        \begin{array}{l}
        t_1 := \frac{\cos th}{\sqrt{2}}\\
        \mathbf{if}\;\left(a2 \cdot a2\right) \cdot t\_1 + t\_1 \cdot \left(a1\_m \cdot a1\_m\right) \leq -5 \cdot 10^{-122}:\\
        \;\;\;\;\left(\left(\left(a2 \cdot a2\right) \cdot \sqrt{2}\right) \cdot \left(\left(th \cdot th\right) \cdot -0.5\right)\right) \cdot 0.5\\
        
        \mathbf{else}:\\
        \;\;\;\;\frac{\mathsf{fma}\left(a2, a2, a1\_m \cdot a1\_m\right)}{\sqrt{2}}\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if (+.f64 (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a1 a1)) (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a2 a2))) < -4.9999999999999999e-122

          1. Initial program 99.7%

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

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

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

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

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

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

              \[\leadsto \color{blue}{\left(\left(\cos th \cdot \left(a1 \cdot a1\right)\right) \cdot \sqrt{2} + \sqrt{2} \cdot \left(\cos th \cdot \left(a2 \cdot a2\right)\right)\right) \cdot \frac{1}{2}} \]
          4. Applied rewrites99.6%

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

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

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

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

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

              \[\leadsto \left(\left({a1}^{2} \cdot \sqrt{2} + {a2}^{2} \cdot \sqrt{2}\right) + \color{blue}{\left(\frac{-1}{2} \cdot {th}^{2}\right)} \cdot \left({a1}^{2} \cdot \sqrt{2} + {a2}^{2} \cdot \sqrt{2}\right)\right) \cdot \frac{1}{2} \]
            5. distribute-rgt1-inN/A

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

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

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

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

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

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

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

              \[\leadsto \left(\mathsf{fma}\left(\color{blue}{th \cdot th}, \frac{-1}{2}, 1\right) \cdot \left({a1}^{2} \cdot \sqrt{2} + {a2}^{2} \cdot \sqrt{2}\right)\right) \cdot \frac{1}{2} \]
          7. Applied rewrites43.7%

            \[\leadsto \color{blue}{\left(\mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot \left(\mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \cdot \sqrt{2}\right)\right)} \cdot 0.5 \]
          8. Taylor expanded in a1 around 0

            \[\leadsto \left(\mathsf{fma}\left(th \cdot th, \frac{-1}{2}, 1\right) \cdot \left({a2}^{2} \cdot \sqrt{\color{blue}{2}}\right)\right) \cdot \frac{1}{2} \]
          9. Step-by-step derivation
            1. Applied rewrites34.1%

              \[\leadsto \left(\mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot \left(\left(a2 \cdot a2\right) \cdot \sqrt{\color{blue}{2}}\right)\right) \cdot 0.5 \]
            2. Taylor expanded in th around inf

              \[\leadsto \left(\left(\frac{-1}{2} \cdot {th}^{2}\right) \cdot \left(\color{blue}{\left(a2 \cdot a2\right)} \cdot \sqrt{2}\right)\right) \cdot \frac{1}{2} \]
            3. Step-by-step derivation
              1. Applied rewrites34.1%

                \[\leadsto \left(\left(\left(th \cdot th\right) \cdot -0.5\right) \cdot \left(\color{blue}{\left(a2 \cdot a2\right)} \cdot \sqrt{2}\right)\right) \cdot 0.5 \]

              if -4.9999999999999999e-122 < (+.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 99.7%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
              6. Step-by-step derivation
                1. lower-sqrt.f6482.4

                  \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
              7. Applied rewrites82.4%

                \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
            4. Recombined 2 regimes into one program.
            5. Final simplification73.9%

              \[\leadsto \begin{array}{l} \mathbf{if}\;\left(a2 \cdot a2\right) \cdot \frac{\cos th}{\sqrt{2}} + \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) \leq -5 \cdot 10^{-122}:\\ \;\;\;\;\left(\left(\left(a2 \cdot a2\right) \cdot \sqrt{2}\right) \cdot \left(\left(th \cdot th\right) \cdot -0.5\right)\right) \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}}\\ \end{array} \]
            6. Add Preprocessing

            Alternative 5: 99.6% accurate, 1.9× speedup?

            \[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \frac{\mathsf{fma}\left(a2, a2, a1\_m \cdot a1\_m\right)}{\sqrt{2}} \cdot \cos th \end{array} \]
            a1_m = (fabs.f64 a1)
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            (FPCore (a1_m a2 th)
             :precision binary64
             (* (/ (fma a2 a2 (* a1_m a1_m)) (sqrt 2.0)) (cos th)))
            a1_m = fabs(a1);
            assert(a1_m < a2 && a2 < th);
            double code(double a1_m, double a2, double th) {
            	return (fma(a2, a2, (a1_m * a1_m)) / sqrt(2.0)) * cos(th);
            }
            
            a1_m = abs(a1)
            a1_m, a2, th = sort([a1_m, a2, th])
            function code(a1_m, a2, th)
            	return Float64(Float64(fma(a2, a2, Float64(a1_m * a1_m)) / sqrt(2.0)) * cos(th))
            end
            
            a1_m = N[Abs[a1], $MachinePrecision]
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            code[a1$95$m_, a2_, th_] := N[(N[(N[(a2 * a2 + N[(a1$95$m * a1$95$m), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision]
            
            \begin{array}{l}
            a1_m = \left|a1\right|
            \\
            [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
            \\
            \frac{\mathsf{fma}\left(a2, a2, a1\_m \cdot a1\_m\right)}{\sqrt{2}} \cdot \cos th
            \end{array}
            
            Derivation
            1. Initial program 99.7%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

            Alternative 6: 99.6% accurate, 1.9× speedup?

            \[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ 0.5 \cdot \left(\left(\cos th \cdot \mathsf{fma}\left(a2, a2, a1\_m \cdot a1\_m\right)\right) \cdot \sqrt{2}\right) \end{array} \]
            a1_m = (fabs.f64 a1)
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            (FPCore (a1_m a2 th)
             :precision binary64
             (* 0.5 (* (* (cos th) (fma a2 a2 (* a1_m a1_m))) (sqrt 2.0))))
            a1_m = fabs(a1);
            assert(a1_m < a2 && a2 < th);
            double code(double a1_m, double a2, double th) {
            	return 0.5 * ((cos(th) * fma(a2, a2, (a1_m * a1_m))) * sqrt(2.0));
            }
            
            a1_m = abs(a1)
            a1_m, a2, th = sort([a1_m, a2, th])
            function code(a1_m, a2, th)
            	return Float64(0.5 * Float64(Float64(cos(th) * fma(a2, a2, Float64(a1_m * a1_m))) * sqrt(2.0)))
            end
            
            a1_m = N[Abs[a1], $MachinePrecision]
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            code[a1$95$m_, a2_, th_] := N[(0.5 * N[(N[(N[Cos[th], $MachinePrecision] * N[(a2 * a2 + N[(a1$95$m * a1$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
            
            \begin{array}{l}
            a1_m = \left|a1\right|
            \\
            [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
            \\
            0.5 \cdot \left(\left(\cos th \cdot \mathsf{fma}\left(a2, a2, a1\_m \cdot a1\_m\right)\right) \cdot \sqrt{2}\right)
            \end{array}
            
            Derivation
            1. Initial program 99.7%

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

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

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

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

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

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

                \[\leadsto \color{blue}{\left(\left(\cos th \cdot \left(a1 \cdot a1\right)\right) \cdot \sqrt{2} + \sqrt{2} \cdot \left(\cos th \cdot \left(a2 \cdot a2\right)\right)\right) \cdot \frac{1}{2}} \]
            4. Applied rewrites99.6%

              \[\leadsto \color{blue}{\mathsf{fma}\left(a2 \cdot \cos th, a2 \cdot \sqrt{2}, \left(a1 \cdot \cos th\right) \cdot \left(a1 \cdot \sqrt{2}\right)\right) \cdot 0.5} \]
            5. Step-by-step derivation
              1. lift-fma.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                \[\leadsto \left(\sqrt{2} \cdot \color{blue}{\left(\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \cos th\right)}\right) \cdot \frac{1}{2} \]
            6. Applied rewrites99.5%

              \[\leadsto \color{blue}{\left(\sqrt{2} \cdot \left(\cos th \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right)\right)} \cdot 0.5 \]
            7. Final simplification99.5%

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

            Alternative 7: 99.6% accurate, 1.9× speedup?

            \[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \left(\mathsf{fma}\left(a1\_m, a1\_m, a2 \cdot a2\right) \cdot \left(\sqrt{2} \cdot \cos th\right)\right) \cdot 0.5 \end{array} \]
            a1_m = (fabs.f64 a1)
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            (FPCore (a1_m a2 th)
             :precision binary64
             (* (* (fma a1_m a1_m (* a2 a2)) (* (sqrt 2.0) (cos th))) 0.5))
            a1_m = fabs(a1);
            assert(a1_m < a2 && a2 < th);
            double code(double a1_m, double a2, double th) {
            	return (fma(a1_m, a1_m, (a2 * a2)) * (sqrt(2.0) * cos(th))) * 0.5;
            }
            
            a1_m = abs(a1)
            a1_m, a2, th = sort([a1_m, a2, th])
            function code(a1_m, a2, th)
            	return Float64(Float64(fma(a1_m, a1_m, Float64(a2 * a2)) * Float64(sqrt(2.0) * cos(th))) * 0.5)
            end
            
            a1_m = N[Abs[a1], $MachinePrecision]
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            code[a1$95$m_, a2_, th_] := N[(N[(N[(a1$95$m * a1$95$m + N[(a2 * a2), $MachinePrecision]), $MachinePrecision] * N[(N[Sqrt[2.0], $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision]
            
            \begin{array}{l}
            a1_m = \left|a1\right|
            \\
            [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
            \\
            \left(\mathsf{fma}\left(a1\_m, a1\_m, a2 \cdot a2\right) \cdot \left(\sqrt{2} \cdot \cos th\right)\right) \cdot 0.5
            \end{array}
            
            Derivation
            1. Initial program 99.7%

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

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

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

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

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

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

                \[\leadsto \color{blue}{\left(\left(\cos th \cdot \left(a1 \cdot a1\right)\right) \cdot \sqrt{2} + \sqrt{2} \cdot \left(\cos th \cdot \left(a2 \cdot a2\right)\right)\right) \cdot \frac{1}{2}} \]
            4. Applied rewrites99.6%

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

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

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

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

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

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

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

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

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

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

                \[\leadsto \left(\left(\sqrt{2} \cdot \cos th\right) \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right)\right) \cdot \frac{1}{2} \]
              10. lower-*.f6499.5

                \[\leadsto \left(\left(\sqrt{2} \cdot \cos th\right) \cdot \mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right)\right) \cdot 0.5 \]
            7. Applied rewrites99.5%

              \[\leadsto \color{blue}{\left(\left(\sqrt{2} \cdot \cos th\right) \cdot \mathsf{fma}\left(a1, a1, a2 \cdot a2\right)\right)} \cdot 0.5 \]
            8. Final simplification99.5%

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

            Alternative 8: 77.7% accurate, 2.0× speedup?

            \[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \left(a2 \cdot a2\right) \cdot \frac{\cos th}{\sqrt{2}} \end{array} \]
            a1_m = (fabs.f64 a1)
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            (FPCore (a1_m a2 th) :precision binary64 (* (* a2 a2) (/ (cos th) (sqrt 2.0))))
            a1_m = fabs(a1);
            assert(a1_m < a2 && a2 < th);
            double code(double a1_m, double a2, double th) {
            	return (a2 * a2) * (cos(th) / sqrt(2.0));
            }
            
            a1_m = abs(a1)
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            real(8) function code(a1_m, a2, th)
                real(8), intent (in) :: a1_m
                real(8), intent (in) :: a2
                real(8), intent (in) :: th
                code = (a2 * a2) * (cos(th) / sqrt(2.0d0))
            end function
            
            a1_m = Math.abs(a1);
            assert a1_m < a2 && a2 < th;
            public static double code(double a1_m, double a2, double th) {
            	return (a2 * a2) * (Math.cos(th) / Math.sqrt(2.0));
            }
            
            a1_m = math.fabs(a1)
            [a1_m, a2, th] = sort([a1_m, a2, th])
            def code(a1_m, a2, th):
            	return (a2 * a2) * (math.cos(th) / math.sqrt(2.0))
            
            a1_m = abs(a1)
            a1_m, a2, th = sort([a1_m, a2, th])
            function code(a1_m, a2, th)
            	return Float64(Float64(a2 * a2) * Float64(cos(th) / sqrt(2.0)))
            end
            
            a1_m = abs(a1);
            a1_m, a2, th = num2cell(sort([a1_m, a2, th])){:}
            function tmp = code(a1_m, a2, th)
            	tmp = (a2 * a2) * (cos(th) / sqrt(2.0));
            end
            
            a1_m = N[Abs[a1], $MachinePrecision]
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            code[a1$95$m_, a2_, th_] := N[(N[(a2 * a2), $MachinePrecision] * N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
            
            \begin{array}{l}
            a1_m = \left|a1\right|
            \\
            [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
            \\
            \left(a2 \cdot a2\right) \cdot \frac{\cos th}{\sqrt{2}}
            \end{array}
            
            Derivation
            1. Initial program 99.7%

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

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

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

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

                \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
              5. *-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.f6499.7

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

              \[\leadsto \color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \frac{\cos th}{\sqrt{2}}} \]
            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-*.f6458.3

                \[\leadsto \color{blue}{\left(a2 \cdot a2\right)} \cdot \frac{\cos th}{\sqrt{2}} \]
            7. Applied rewrites58.3%

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

            Alternative 9: 77.8% accurate, 2.0× speedup?

            \[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \frac{a2}{\sqrt{2}} \cdot \left(\cos th \cdot a2\right) \end{array} \]
            a1_m = (fabs.f64 a1)
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            (FPCore (a1_m a2 th) :precision binary64 (* (/ a2 (sqrt 2.0)) (* (cos th) a2)))
            a1_m = fabs(a1);
            assert(a1_m < a2 && a2 < th);
            double code(double a1_m, double a2, double th) {
            	return (a2 / sqrt(2.0)) * (cos(th) * a2);
            }
            
            a1_m = abs(a1)
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            real(8) function code(a1_m, a2, th)
                real(8), intent (in) :: a1_m
                real(8), intent (in) :: a2
                real(8), intent (in) :: th
                code = (a2 / sqrt(2.0d0)) * (cos(th) * a2)
            end function
            
            a1_m = Math.abs(a1);
            assert a1_m < a2 && a2 < th;
            public static double code(double a1_m, double a2, double th) {
            	return (a2 / Math.sqrt(2.0)) * (Math.cos(th) * a2);
            }
            
            a1_m = math.fabs(a1)
            [a1_m, a2, th] = sort([a1_m, a2, th])
            def code(a1_m, a2, th):
            	return (a2 / math.sqrt(2.0)) * (math.cos(th) * a2)
            
            a1_m = abs(a1)
            a1_m, a2, th = sort([a1_m, a2, th])
            function code(a1_m, a2, th)
            	return Float64(Float64(a2 / sqrt(2.0)) * Float64(cos(th) * a2))
            end
            
            a1_m = abs(a1);
            a1_m, a2, th = num2cell(sort([a1_m, a2, th])){:}
            function tmp = code(a1_m, a2, th)
            	tmp = (a2 / sqrt(2.0)) * (cos(th) * a2);
            end
            
            a1_m = N[Abs[a1], $MachinePrecision]
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            code[a1$95$m_, a2_, th_] := N[(N[(a2 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[(N[Cos[th], $MachinePrecision] * a2), $MachinePrecision]), $MachinePrecision]
            
            \begin{array}{l}
            a1_m = \left|a1\right|
            \\
            [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
            \\
            \frac{a2}{\sqrt{2}} \cdot \left(\cos th \cdot a2\right)
            \end{array}
            
            Derivation
            1. Initial program 99.7%

              \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
            2. Add Preprocessing
            3. 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. Final simplification58.2%

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

            Alternative 10: 77.8% accurate, 2.0× speedup?

            \[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \left(\left(\left(\sqrt{2} \cdot a2\right) \cdot a2\right) \cdot \cos th\right) \cdot 0.5 \end{array} \]
            a1_m = (fabs.f64 a1)
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            (FPCore (a1_m a2 th)
             :precision binary64
             (* (* (* (* (sqrt 2.0) a2) a2) (cos th)) 0.5))
            a1_m = fabs(a1);
            assert(a1_m < a2 && a2 < th);
            double code(double a1_m, double a2, double th) {
            	return (((sqrt(2.0) * a2) * a2) * cos(th)) * 0.5;
            }
            
            a1_m = abs(a1)
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            real(8) function code(a1_m, a2, th)
                real(8), intent (in) :: a1_m
                real(8), intent (in) :: a2
                real(8), intent (in) :: th
                code = (((sqrt(2.0d0) * a2) * a2) * cos(th)) * 0.5d0
            end function
            
            a1_m = Math.abs(a1);
            assert a1_m < a2 && a2 < th;
            public static double code(double a1_m, double a2, double th) {
            	return (((Math.sqrt(2.0) * a2) * a2) * Math.cos(th)) * 0.5;
            }
            
            a1_m = math.fabs(a1)
            [a1_m, a2, th] = sort([a1_m, a2, th])
            def code(a1_m, a2, th):
            	return (((math.sqrt(2.0) * a2) * a2) * math.cos(th)) * 0.5
            
            a1_m = abs(a1)
            a1_m, a2, th = sort([a1_m, a2, th])
            function code(a1_m, a2, th)
            	return Float64(Float64(Float64(Float64(sqrt(2.0) * a2) * a2) * cos(th)) * 0.5)
            end
            
            a1_m = abs(a1);
            a1_m, a2, th = num2cell(sort([a1_m, a2, th])){:}
            function tmp = code(a1_m, a2, th)
            	tmp = (((sqrt(2.0) * a2) * a2) * cos(th)) * 0.5;
            end
            
            a1_m = N[Abs[a1], $MachinePrecision]
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            code[a1$95$m_, a2_, th_] := N[(N[(N[(N[(N[Sqrt[2.0], $MachinePrecision] * a2), $MachinePrecision] * a2), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision]
            
            \begin{array}{l}
            a1_m = \left|a1\right|
            \\
            [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
            \\
            \left(\left(\left(\sqrt{2} \cdot a2\right) \cdot a2\right) \cdot \cos th\right) \cdot 0.5
            \end{array}
            
            Derivation
            1. Initial program 99.7%

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

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

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

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

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

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

                \[\leadsto \color{blue}{\left(\left(\cos th \cdot \left(a1 \cdot a1\right)\right) \cdot \sqrt{2} + \sqrt{2} \cdot \left(\cos th \cdot \left(a2 \cdot a2\right)\right)\right) \cdot \frac{1}{2}} \]
            4. Applied rewrites99.6%

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

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

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

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

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

                \[\leadsto \left(\left({a1}^{2} \cdot \sqrt{2} + {a2}^{2} \cdot \sqrt{2}\right) + \color{blue}{\left(\frac{-1}{2} \cdot {th}^{2}\right)} \cdot \left({a1}^{2} \cdot \sqrt{2} + {a2}^{2} \cdot \sqrt{2}\right)\right) \cdot \frac{1}{2} \]
              5. distribute-rgt1-inN/A

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

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

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

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

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

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

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

                \[\leadsto \left(\mathsf{fma}\left(\color{blue}{th \cdot th}, \frac{-1}{2}, 1\right) \cdot \left({a1}^{2} \cdot \sqrt{2} + {a2}^{2} \cdot \sqrt{2}\right)\right) \cdot \frac{1}{2} \]
            7. Applied rewrites59.7%

              \[\leadsto \color{blue}{\left(\mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot \left(\mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \cdot \sqrt{2}\right)\right)} \cdot 0.5 \]
            8. Taylor expanded in a1 around 0

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

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

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

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

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

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

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

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

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

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

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

                \[\leadsto \left(\left(\left(\color{blue}{\sqrt{2}} \cdot a2\right) \cdot a2\right) \cdot \cos th\right) \cdot \frac{1}{2} \]
              12. lower-cos.f6458.2

                \[\leadsto \left(\left(\left(\sqrt{2} \cdot a2\right) \cdot a2\right) \cdot \color{blue}{\cos th}\right) \cdot 0.5 \]
            10. Applied rewrites58.2%

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

            Alternative 11: 77.8% accurate, 2.0× speedup?

            \[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \left(\left(a2 \cdot a2\right) \cdot \left(\sqrt{2} \cdot \cos th\right)\right) \cdot 0.5 \end{array} \]
            a1_m = (fabs.f64 a1)
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            (FPCore (a1_m a2 th)
             :precision binary64
             (* (* (* a2 a2) (* (sqrt 2.0) (cos th))) 0.5))
            a1_m = fabs(a1);
            assert(a1_m < a2 && a2 < th);
            double code(double a1_m, double a2, double th) {
            	return ((a2 * a2) * (sqrt(2.0) * cos(th))) * 0.5;
            }
            
            a1_m = abs(a1)
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            real(8) function code(a1_m, a2, th)
                real(8), intent (in) :: a1_m
                real(8), intent (in) :: a2
                real(8), intent (in) :: th
                code = ((a2 * a2) * (sqrt(2.0d0) * cos(th))) * 0.5d0
            end function
            
            a1_m = Math.abs(a1);
            assert a1_m < a2 && a2 < th;
            public static double code(double a1_m, double a2, double th) {
            	return ((a2 * a2) * (Math.sqrt(2.0) * Math.cos(th))) * 0.5;
            }
            
            a1_m = math.fabs(a1)
            [a1_m, a2, th] = sort([a1_m, a2, th])
            def code(a1_m, a2, th):
            	return ((a2 * a2) * (math.sqrt(2.0) * math.cos(th))) * 0.5
            
            a1_m = abs(a1)
            a1_m, a2, th = sort([a1_m, a2, th])
            function code(a1_m, a2, th)
            	return Float64(Float64(Float64(a2 * a2) * Float64(sqrt(2.0) * cos(th))) * 0.5)
            end
            
            a1_m = abs(a1);
            a1_m, a2, th = num2cell(sort([a1_m, a2, th])){:}
            function tmp = code(a1_m, a2, th)
            	tmp = ((a2 * a2) * (sqrt(2.0) * cos(th))) * 0.5;
            end
            
            a1_m = N[Abs[a1], $MachinePrecision]
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            code[a1$95$m_, a2_, th_] := N[(N[(N[(a2 * a2), $MachinePrecision] * N[(N[Sqrt[2.0], $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision]
            
            \begin{array}{l}
            a1_m = \left|a1\right|
            \\
            [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
            \\
            \left(\left(a2 \cdot a2\right) \cdot \left(\sqrt{2} \cdot \cos th\right)\right) \cdot 0.5
            \end{array}
            
            Derivation
            1. Initial program 99.7%

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

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

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

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

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

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

                \[\leadsto \color{blue}{\left(\left(\cos th \cdot \left(a1 \cdot a1\right)\right) \cdot \sqrt{2} + \sqrt{2} \cdot \left(\cos th \cdot \left(a2 \cdot a2\right)\right)\right) \cdot \frac{1}{2}} \]
            4. Applied rewrites99.6%

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

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

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

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

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

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

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

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

                \[\leadsto \left(\left(\sqrt{2} \cdot \cos th\right) \cdot \color{blue}{\left(a2 \cdot a2\right)}\right) \cdot \frac{1}{2} \]
              8. lower-*.f6458.2

                \[\leadsto \left(\left(\sqrt{2} \cdot \cos th\right) \cdot \color{blue}{\left(a2 \cdot a2\right)}\right) \cdot 0.5 \]
            7. Applied rewrites58.2%

              \[\leadsto \color{blue}{\left(\left(\sqrt{2} \cdot \cos th\right) \cdot \left(a2 \cdot a2\right)\right)} \cdot 0.5 \]
            8. Final simplification58.2%

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

            Alternative 12: 65.7% accurate, 8.1× speedup?

            \[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \frac{\mathsf{fma}\left(a2, a2, a1\_m \cdot a1\_m\right)}{\sqrt{2}} \end{array} \]
            a1_m = (fabs.f64 a1)
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            (FPCore (a1_m a2 th)
             :precision binary64
             (/ (fma a2 a2 (* a1_m a1_m)) (sqrt 2.0)))
            a1_m = fabs(a1);
            assert(a1_m < a2 && a2 < th);
            double code(double a1_m, double a2, double th) {
            	return fma(a2, a2, (a1_m * a1_m)) / sqrt(2.0);
            }
            
            a1_m = abs(a1)
            a1_m, a2, th = sort([a1_m, a2, th])
            function code(a1_m, a2, th)
            	return Float64(fma(a2, a2, Float64(a1_m * a1_m)) / sqrt(2.0))
            end
            
            a1_m = N[Abs[a1], $MachinePrecision]
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            code[a1$95$m_, a2_, th_] := N[(N[(a2 * a2 + N[(a1$95$m * a1$95$m), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
            
            \begin{array}{l}
            a1_m = \left|a1\right|
            \\
            [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
            \\
            \frac{\mathsf{fma}\left(a2, a2, a1\_m \cdot a1\_m\right)}{\sqrt{2}}
            \end{array}
            
            Derivation
            1. Initial program 99.7%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
            6. Step-by-step derivation
              1. lower-sqrt.f6468.0

                \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
            7. Applied rewrites68.0%

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

            Alternative 13: 65.7% accurate, 8.1× speedup?

            \[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \frac{\mathsf{fma}\left(a1\_m, a1\_m, a2 \cdot a2\right)}{\sqrt{2}} \end{array} \]
            a1_m = (fabs.f64 a1)
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            (FPCore (a1_m a2 th)
             :precision binary64
             (/ (fma a1_m a1_m (* a2 a2)) (sqrt 2.0)))
            a1_m = fabs(a1);
            assert(a1_m < a2 && a2 < th);
            double code(double a1_m, double a2, double th) {
            	return fma(a1_m, a1_m, (a2 * a2)) / sqrt(2.0);
            }
            
            a1_m = abs(a1)
            a1_m, a2, th = sort([a1_m, a2, th])
            function code(a1_m, a2, th)
            	return Float64(fma(a1_m, a1_m, Float64(a2 * a2)) / sqrt(2.0))
            end
            
            a1_m = N[Abs[a1], $MachinePrecision]
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            code[a1$95$m_, a2_, th_] := N[(N[(a1$95$m * a1$95$m + N[(a2 * a2), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
            
            \begin{array}{l}
            a1_m = \left|a1\right|
            \\
            [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
            \\
            \frac{\mathsf{fma}\left(a1\_m, a1\_m, a2 \cdot a2\right)}{\sqrt{2}}
            \end{array}
            
            Derivation
            1. Initial program 99.7%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \frac{\color{blue}{{a1}^{2} + {a2}^{2}}}{\sqrt{2}} \]
            6. Step-by-step derivation
              1. unpow2N/A

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

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

                \[\leadsto \frac{\mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right)}{\sqrt{2}} \]
              4. lower-*.f6468.1

                \[\leadsto \frac{\mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right)}{\sqrt{2}} \]
            7. Applied rewrites68.1%

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

            Alternative 14: 65.8% accurate, 8.3× speedup?

            \[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \left(\mathsf{fma}\left(a1\_m, a1\_m, a2 \cdot a2\right) \cdot \sqrt{2}\right) \cdot 0.5 \end{array} \]
            a1_m = (fabs.f64 a1)
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            (FPCore (a1_m a2 th)
             :precision binary64
             (* (* (fma a1_m a1_m (* a2 a2)) (sqrt 2.0)) 0.5))
            a1_m = fabs(a1);
            assert(a1_m < a2 && a2 < th);
            double code(double a1_m, double a2, double th) {
            	return (fma(a1_m, a1_m, (a2 * a2)) * sqrt(2.0)) * 0.5;
            }
            
            a1_m = abs(a1)
            a1_m, a2, th = sort([a1_m, a2, th])
            function code(a1_m, a2, th)
            	return Float64(Float64(fma(a1_m, a1_m, Float64(a2 * a2)) * sqrt(2.0)) * 0.5)
            end
            
            a1_m = N[Abs[a1], $MachinePrecision]
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            code[a1$95$m_, a2_, th_] := N[(N[(N[(a1$95$m * a1$95$m + N[(a2 * a2), $MachinePrecision]), $MachinePrecision] * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision]
            
            \begin{array}{l}
            a1_m = \left|a1\right|
            \\
            [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
            \\
            \left(\mathsf{fma}\left(a1\_m, a1\_m, a2 \cdot a2\right) \cdot \sqrt{2}\right) \cdot 0.5
            \end{array}
            
            Derivation
            1. Initial program 99.7%

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

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

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

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

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

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

                \[\leadsto \color{blue}{\left(\left(\cos th \cdot \left(a1 \cdot a1\right)\right) \cdot \sqrt{2} + \sqrt{2} \cdot \left(\cos th \cdot \left(a2 \cdot a2\right)\right)\right) \cdot \frac{1}{2}} \]
            4. Applied rewrites99.6%

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

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

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

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

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

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

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

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

                \[\leadsto \left(\mathsf{fma}\left(a1, a1, \color{blue}{a2 \cdot a2}\right) \cdot \sqrt{2}\right) \cdot \frac{1}{2} \]
              8. lower-sqrt.f6468.0

                \[\leadsto \left(\mathsf{fma}\left(a1, a1, a2 \cdot a2\right) \cdot \color{blue}{\sqrt{2}}\right) \cdot 0.5 \]
            7. Applied rewrites68.0%

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

            Alternative 15: 52.5% accurate, 9.9× speedup?

            \[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \frac{a2}{\sqrt{2}} \cdot a2 \end{array} \]
            a1_m = (fabs.f64 a1)
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            (FPCore (a1_m a2 th) :precision binary64 (* (/ a2 (sqrt 2.0)) a2))
            a1_m = fabs(a1);
            assert(a1_m < a2 && a2 < th);
            double code(double a1_m, double a2, double th) {
            	return (a2 / sqrt(2.0)) * a2;
            }
            
            a1_m = abs(a1)
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            real(8) function code(a1_m, a2, th)
                real(8), intent (in) :: a1_m
                real(8), intent (in) :: a2
                real(8), intent (in) :: th
                code = (a2 / sqrt(2.0d0)) * a2
            end function
            
            a1_m = Math.abs(a1);
            assert a1_m < a2 && a2 < th;
            public static double code(double a1_m, double a2, double th) {
            	return (a2 / Math.sqrt(2.0)) * a2;
            }
            
            a1_m = math.fabs(a1)
            [a1_m, a2, th] = sort([a1_m, a2, th])
            def code(a1_m, a2, th):
            	return (a2 / math.sqrt(2.0)) * a2
            
            a1_m = abs(a1)
            a1_m, a2, th = sort([a1_m, a2, th])
            function code(a1_m, a2, th)
            	return Float64(Float64(a2 / sqrt(2.0)) * a2)
            end
            
            a1_m = abs(a1);
            a1_m, a2, th = num2cell(sort([a1_m, a2, th])){:}
            function tmp = code(a1_m, a2, th)
            	tmp = (a2 / sqrt(2.0)) * a2;
            end
            
            a1_m = N[Abs[a1], $MachinePrecision]
            NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
            code[a1$95$m_, a2_, th_] := N[(N[(a2 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * a2), $MachinePrecision]
            
            \begin{array}{l}
            a1_m = \left|a1\right|
            \\
            [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
            \\
            \frac{a2}{\sqrt{2}} \cdot a2
            \end{array}
            
            Derivation
            1. Initial program 99.7%

              \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
            2. Add Preprocessing
            3. 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. unpow2N/A

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

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

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

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

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

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

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

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

                \[\leadsto \mathsf{fma}\left(\frac{a1}{\sqrt{2}}, a1, \color{blue}{\frac{a2}{\sqrt{2}}} \cdot a2\right) \]
              10. lower-sqrt.f6468.0

                \[\leadsto \mathsf{fma}\left(\frac{a1}{\sqrt{2}}, a1, \frac{a2}{\color{blue}{\sqrt{2}}} \cdot a2\right) \]
            5. Applied rewrites68.0%

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

              \[\leadsto \frac{{a2}^{2}}{\color{blue}{\sqrt{2}}} \]
            7. Step-by-step derivation
              1. Applied rewrites40.6%

                \[\leadsto a2 \cdot \color{blue}{\frac{a2}{\sqrt{2}}} \]
              2. Final simplification40.6%

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

              Alternative 16: 26.5% accurate, 9.9× speedup?

              \[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \frac{a1\_m}{\sqrt{2}} \cdot a1\_m \end{array} \]
              a1_m = (fabs.f64 a1)
              NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
              (FPCore (a1_m a2 th) :precision binary64 (* (/ a1_m (sqrt 2.0)) a1_m))
              a1_m = fabs(a1);
              assert(a1_m < a2 && a2 < th);
              double code(double a1_m, double a2, double th) {
              	return (a1_m / sqrt(2.0)) * a1_m;
              }
              
              a1_m = abs(a1)
              NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
              real(8) function code(a1_m, a2, th)
                  real(8), intent (in) :: a1_m
                  real(8), intent (in) :: a2
                  real(8), intent (in) :: th
                  code = (a1_m / sqrt(2.0d0)) * a1_m
              end function
              
              a1_m = Math.abs(a1);
              assert a1_m < a2 && a2 < th;
              public static double code(double a1_m, double a2, double th) {
              	return (a1_m / Math.sqrt(2.0)) * a1_m;
              }
              
              a1_m = math.fabs(a1)
              [a1_m, a2, th] = sort([a1_m, a2, th])
              def code(a1_m, a2, th):
              	return (a1_m / math.sqrt(2.0)) * a1_m
              
              a1_m = abs(a1)
              a1_m, a2, th = sort([a1_m, a2, th])
              function code(a1_m, a2, th)
              	return Float64(Float64(a1_m / sqrt(2.0)) * a1_m)
              end
              
              a1_m = abs(a1);
              a1_m, a2, th = num2cell(sort([a1_m, a2, th])){:}
              function tmp = code(a1_m, a2, th)
              	tmp = (a1_m / sqrt(2.0)) * a1_m;
              end
              
              a1_m = N[Abs[a1], $MachinePrecision]
              NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
              code[a1$95$m_, a2_, th_] := N[(N[(a1$95$m / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * a1$95$m), $MachinePrecision]
              
              \begin{array}{l}
              a1_m = \left|a1\right|
              \\
              [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
              \\
              \frac{a1\_m}{\sqrt{2}} \cdot a1\_m
              \end{array}
              
              Derivation
              1. Initial program 99.7%

                \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
              2. Add Preprocessing
              3. 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. unpow2N/A

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

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

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

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

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

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

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

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

                  \[\leadsto \mathsf{fma}\left(\frac{a1}{\sqrt{2}}, a1, \color{blue}{\frac{a2}{\sqrt{2}}} \cdot a2\right) \]
                10. lower-sqrt.f6468.0

                  \[\leadsto \mathsf{fma}\left(\frac{a1}{\sqrt{2}}, a1, \frac{a2}{\color{blue}{\sqrt{2}}} \cdot a2\right) \]
              5. Applied rewrites68.0%

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

                \[\leadsto \frac{{a1}^{2}}{\color{blue}{\sqrt{2}}} \]
              7. Step-by-step derivation
                1. Applied rewrites41.7%

                  \[\leadsto a1 \cdot \color{blue}{\frac{a1}{\sqrt{2}}} \]
                2. Final simplification41.7%

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

                Reproduce

                ?
                herbie shell --seed 2024237 
                (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))))