Migdal et al, Equation (64)

Percentage Accurate: 99.6% → 99.6%
Time: 6.9s
Alternatives: 9
Speedup: 1.0×

Specification

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

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

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 9 alternatives:

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

Initial Program: 99.6% accurate, 1.0× speedup?

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

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

Alternative 1: 99.6% accurate, 0.8× speedup?

\[\begin{array}{l} a2_m = \left|a2\right| \\ a1_m = \left|a1\right| \\ [a1_m, a2_m, th] = \mathsf{sort}([a1_m, a2_m, th])\\ \\ \left(a2\_m \cdot a2\_m\right) \cdot \left({4}^{-0.25} \cdot \cos th\right) + \left(a1\_m \cdot a1\_m\right) \cdot \frac{\cos th}{\sqrt{2}} \end{array} \]
a2_m = (fabs.f64 a2)
a1_m = (fabs.f64 a1)
NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
(FPCore (a1_m a2_m th)
 :precision binary64
 (+
  (* (* a2_m a2_m) (* (pow 4.0 -0.25) (cos th)))
  (* (* a1_m a1_m) (/ (cos th) (sqrt 2.0)))))
a2_m = fabs(a2);
a1_m = fabs(a1);
assert(a1_m < a2_m && a2_m < th);
double code(double a1_m, double a2_m, double th) {
	return ((a2_m * a2_m) * (pow(4.0, -0.25) * cos(th))) + ((a1_m * a1_m) * (cos(th) / sqrt(2.0)));
}
a2_m = abs(a2)
a1_m = abs(a1)
NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
real(8) function code(a1_m, a2_m, th)
    real(8), intent (in) :: a1_m
    real(8), intent (in) :: a2_m
    real(8), intent (in) :: th
    code = ((a2_m * a2_m) * ((4.0d0 ** (-0.25d0)) * cos(th))) + ((a1_m * a1_m) * (cos(th) / sqrt(2.0d0)))
end function
a2_m = Math.abs(a2);
a1_m = Math.abs(a1);
assert a1_m < a2_m && a2_m < th;
public static double code(double a1_m, double a2_m, double th) {
	return ((a2_m * a2_m) * (Math.pow(4.0, -0.25) * Math.cos(th))) + ((a1_m * a1_m) * (Math.cos(th) / Math.sqrt(2.0)));
}
a2_m = math.fabs(a2)
a1_m = math.fabs(a1)
[a1_m, a2_m, th] = sort([a1_m, a2_m, th])
def code(a1_m, a2_m, th):
	return ((a2_m * a2_m) * (math.pow(4.0, -0.25) * math.cos(th))) + ((a1_m * a1_m) * (math.cos(th) / math.sqrt(2.0)))
a2_m = abs(a2)
a1_m = abs(a1)
a1_m, a2_m, th = sort([a1_m, a2_m, th])
function code(a1_m, a2_m, th)
	return Float64(Float64(Float64(a2_m * a2_m) * Float64((4.0 ^ -0.25) * cos(th))) + Float64(Float64(a1_m * a1_m) * Float64(cos(th) / sqrt(2.0))))
end
a2_m = abs(a2);
a1_m = abs(a1);
a1_m, a2_m, th = num2cell(sort([a1_m, a2_m, th])){:}
function tmp = code(a1_m, a2_m, th)
	tmp = ((a2_m * a2_m) * ((4.0 ^ -0.25) * cos(th))) + ((a1_m * a1_m) * (cos(th) / sqrt(2.0)));
end
a2_m = N[Abs[a2], $MachinePrecision]
a1_m = N[Abs[a1], $MachinePrecision]
NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
code[a1$95$m_, a2$95$m_, th_] := N[(N[(N[(a2$95$m * a2$95$m), $MachinePrecision] * N[(N[Power[4.0, -0.25], $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(a1$95$m * a1$95$m), $MachinePrecision] * N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
a2_m = \left|a2\right|
\\
a1_m = \left|a1\right|
\\
[a1_m, a2_m, th] = \mathsf{sort}([a1_m, a2_m, th])\\
\\
\left(a2\_m \cdot a2\_m\right) \cdot \left({4}^{-0.25} \cdot \cos th\right) + \left(a1\_m \cdot a1\_m\right) \cdot \frac{\cos th}{\sqrt{2}}
\end{array}
Derivation
  1. Initial program 99.6%

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \left({\color{blue}{4}}^{\left(\frac{\mathsf{neg}\left(\frac{1}{2}\right)}{2}\right)} \cdot \cos th\right) \cdot \left(a2 \cdot a2\right) \]
    12. metadata-evalN/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \left({4}^{\left(\frac{\color{blue}{\frac{-1}{2}}}{2}\right)} \cdot \cos th\right) \cdot \left(a2 \cdot a2\right) \]
    13. metadata-eval99.5

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \left({4}^{\color{blue}{-0.25}} \cdot \cos th\right) \cdot \left(a2 \cdot a2\right) \]
  4. Applied rewrites99.5%

    \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\left({4}^{-0.25} \cdot \cos th\right)} \cdot \left(a2 \cdot a2\right) \]
  5. Final simplification99.5%

    \[\leadsto \left(a2 \cdot a2\right) \cdot \left({4}^{-0.25} \cdot \cos th\right) + \left(a1 \cdot a1\right) \cdot \frac{\cos th}{\sqrt{2}} \]
  6. Add Preprocessing

Alternative 2: 99.6% accurate, 1.0× speedup?

\[\begin{array}{l} a2_m = \left|a2\right| \\ a1_m = \left|a1\right| \\ [a1_m, a2_m, th] = \mathsf{sort}([a1_m, a2_m, th])\\ \\ \left(\frac{a2\_m}{\sqrt{2}} \cdot \cos th\right) \cdot a2\_m + \left(a1\_m \cdot a1\_m\right) \cdot \frac{\cos th}{\sqrt{2}} \end{array} \]
a2_m = (fabs.f64 a2)
a1_m = (fabs.f64 a1)
NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
(FPCore (a1_m a2_m th)
 :precision binary64
 (+
  (* (* (/ a2_m (sqrt 2.0)) (cos th)) a2_m)
  (* (* a1_m a1_m) (/ (cos th) (sqrt 2.0)))))
a2_m = fabs(a2);
a1_m = fabs(a1);
assert(a1_m < a2_m && a2_m < th);
double code(double a1_m, double a2_m, double th) {
	return (((a2_m / sqrt(2.0)) * cos(th)) * a2_m) + ((a1_m * a1_m) * (cos(th) / sqrt(2.0)));
}
a2_m = abs(a2)
a1_m = abs(a1)
NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
real(8) function code(a1_m, a2_m, th)
    real(8), intent (in) :: a1_m
    real(8), intent (in) :: a2_m
    real(8), intent (in) :: th
    code = (((a2_m / sqrt(2.0d0)) * cos(th)) * a2_m) + ((a1_m * a1_m) * (cos(th) / sqrt(2.0d0)))
end function
a2_m = Math.abs(a2);
a1_m = Math.abs(a1);
assert a1_m < a2_m && a2_m < th;
public static double code(double a1_m, double a2_m, double th) {
	return (((a2_m / Math.sqrt(2.0)) * Math.cos(th)) * a2_m) + ((a1_m * a1_m) * (Math.cos(th) / Math.sqrt(2.0)));
}
a2_m = math.fabs(a2)
a1_m = math.fabs(a1)
[a1_m, a2_m, th] = sort([a1_m, a2_m, th])
def code(a1_m, a2_m, th):
	return (((a2_m / math.sqrt(2.0)) * math.cos(th)) * a2_m) + ((a1_m * a1_m) * (math.cos(th) / math.sqrt(2.0)))
a2_m = abs(a2)
a1_m = abs(a1)
a1_m, a2_m, th = sort([a1_m, a2_m, th])
function code(a1_m, a2_m, th)
	return Float64(Float64(Float64(Float64(a2_m / sqrt(2.0)) * cos(th)) * a2_m) + Float64(Float64(a1_m * a1_m) * Float64(cos(th) / sqrt(2.0))))
end
a2_m = abs(a2);
a1_m = abs(a1);
a1_m, a2_m, th = num2cell(sort([a1_m, a2_m, th])){:}
function tmp = code(a1_m, a2_m, th)
	tmp = (((a2_m / sqrt(2.0)) * cos(th)) * a2_m) + ((a1_m * a1_m) * (cos(th) / sqrt(2.0)));
end
a2_m = N[Abs[a2], $MachinePrecision]
a1_m = N[Abs[a1], $MachinePrecision]
NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
code[a1$95$m_, a2$95$m_, th_] := N[(N[(N[(N[(a2$95$m / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision] * a2$95$m), $MachinePrecision] + N[(N[(a1$95$m * a1$95$m), $MachinePrecision] * N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
a2_m = \left|a2\right|
\\
a1_m = \left|a1\right|
\\
[a1_m, a2_m, th] = \mathsf{sort}([a1_m, a2_m, th])\\
\\
\left(\frac{a2\_m}{\sqrt{2}} \cdot \cos th\right) \cdot a2\_m + \left(a1\_m \cdot a1\_m\right) \cdot \frac{\cos th}{\sqrt{2}}
\end{array}
Derivation
  1. Initial program 99.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\left(\frac{a2}{\sqrt{2}} \cdot \cos th\right) \cdot a2} \]
  5. Final simplification99.6%

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

Alternative 3: 99.6% accurate, 1.0× speedup?

\[\begin{array}{l} a2_m = \left|a2\right| \\ a1_m = \left|a1\right| \\ [a1_m, a2_m, th] = \mathsf{sort}([a1_m, a2_m, th])\\ \\ \left(\frac{a2\_m}{\sqrt{2}} \cdot a2\_m\right) \cdot \cos th + \left(a1\_m \cdot a1\_m\right) \cdot \frac{\cos th}{\sqrt{2}} \end{array} \]
a2_m = (fabs.f64 a2)
a1_m = (fabs.f64 a1)
NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
(FPCore (a1_m a2_m th)
 :precision binary64
 (+
  (* (* (/ a2_m (sqrt 2.0)) a2_m) (cos th))
  (* (* a1_m a1_m) (/ (cos th) (sqrt 2.0)))))
a2_m = fabs(a2);
a1_m = fabs(a1);
assert(a1_m < a2_m && a2_m < th);
double code(double a1_m, double a2_m, double th) {
	return (((a2_m / sqrt(2.0)) * a2_m) * cos(th)) + ((a1_m * a1_m) * (cos(th) / sqrt(2.0)));
}
a2_m = abs(a2)
a1_m = abs(a1)
NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
real(8) function code(a1_m, a2_m, th)
    real(8), intent (in) :: a1_m
    real(8), intent (in) :: a2_m
    real(8), intent (in) :: th
    code = (((a2_m / sqrt(2.0d0)) * a2_m) * cos(th)) + ((a1_m * a1_m) * (cos(th) / sqrt(2.0d0)))
end function
a2_m = Math.abs(a2);
a1_m = Math.abs(a1);
assert a1_m < a2_m && a2_m < th;
public static double code(double a1_m, double a2_m, double th) {
	return (((a2_m / Math.sqrt(2.0)) * a2_m) * Math.cos(th)) + ((a1_m * a1_m) * (Math.cos(th) / Math.sqrt(2.0)));
}
a2_m = math.fabs(a2)
a1_m = math.fabs(a1)
[a1_m, a2_m, th] = sort([a1_m, a2_m, th])
def code(a1_m, a2_m, th):
	return (((a2_m / math.sqrt(2.0)) * a2_m) * math.cos(th)) + ((a1_m * a1_m) * (math.cos(th) / math.sqrt(2.0)))
a2_m = abs(a2)
a1_m = abs(a1)
a1_m, a2_m, th = sort([a1_m, a2_m, th])
function code(a1_m, a2_m, th)
	return Float64(Float64(Float64(Float64(a2_m / sqrt(2.0)) * a2_m) * cos(th)) + Float64(Float64(a1_m * a1_m) * Float64(cos(th) / sqrt(2.0))))
end
a2_m = abs(a2);
a1_m = abs(a1);
a1_m, a2_m, th = num2cell(sort([a1_m, a2_m, th])){:}
function tmp = code(a1_m, a2_m, th)
	tmp = (((a2_m / sqrt(2.0)) * a2_m) * cos(th)) + ((a1_m * a1_m) * (cos(th) / sqrt(2.0)));
end
a2_m = N[Abs[a2], $MachinePrecision]
a1_m = N[Abs[a1], $MachinePrecision]
NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
code[a1$95$m_, a2$95$m_, th_] := N[(N[(N[(N[(a2$95$m / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * a2$95$m), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision] + N[(N[(a1$95$m * a1$95$m), $MachinePrecision] * N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
a2_m = \left|a2\right|
\\
a1_m = \left|a1\right|
\\
[a1_m, a2_m, th] = \mathsf{sort}([a1_m, a2_m, th])\\
\\
\left(\frac{a2\_m}{\sqrt{2}} \cdot a2\_m\right) \cdot \cos th + \left(a1\_m \cdot a1\_m\right) \cdot \frac{\cos th}{\sqrt{2}}
\end{array}
Derivation
  1. Initial program 99.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \left(\color{blue}{\frac{-1 \cdot a2}{\mathsf{neg}\left(\sqrt{2}\right)}} \cdot a2\right) \cdot \cos th \]
    15. neg-mul-1N/A

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

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

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

    \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\left(\frac{a2}{\sqrt{2}} \cdot a2\right) \cdot \cos th} \]
  5. Final simplification99.6%

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

Alternative 4: 78.1% accurate, 1.6× speedup?

\[\begin{array}{l} a2_m = \left|a2\right| \\ a1_m = \left|a1\right| \\ [a1_m, a2_m, th] = \mathsf{sort}([a1_m, a2_m, th])\\ \\ \begin{array}{l} t_1 := \frac{a1\_m}{\sqrt{2}} \cdot a1\_m\\ \mathbf{if}\;\cos th \leq -0.005:\\ \;\;\;\;\left(-a2\_m\right) \cdot \frac{a2\_m}{\sqrt{2}} + t\_1\\ \mathbf{else}:\\ \;\;\;\;\sqrt{\frac{a2\_m \cdot a2\_m}{2}} \cdot a2\_m + t\_1\\ \end{array} \end{array} \]
a2_m = (fabs.f64 a2)
a1_m = (fabs.f64 a1)
NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
(FPCore (a1_m a2_m th)
 :precision binary64
 (let* ((t_1 (* (/ a1_m (sqrt 2.0)) a1_m)))
   (if (<= (cos th) -0.005)
     (+ (* (- a2_m) (/ a2_m (sqrt 2.0))) t_1)
     (+ (* (sqrt (/ (* a2_m a2_m) 2.0)) a2_m) t_1))))
a2_m = fabs(a2);
a1_m = fabs(a1);
assert(a1_m < a2_m && a2_m < th);
double code(double a1_m, double a2_m, double th) {
	double t_1 = (a1_m / sqrt(2.0)) * a1_m;
	double tmp;
	if (cos(th) <= -0.005) {
		tmp = (-a2_m * (a2_m / sqrt(2.0))) + t_1;
	} else {
		tmp = (sqrt(((a2_m * a2_m) / 2.0)) * a2_m) + t_1;
	}
	return tmp;
}
a2_m = abs(a2)
a1_m = abs(a1)
NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
real(8) function code(a1_m, a2_m, th)
    real(8), intent (in) :: a1_m
    real(8), intent (in) :: a2_m
    real(8), intent (in) :: th
    real(8) :: t_1
    real(8) :: tmp
    t_1 = (a1_m / sqrt(2.0d0)) * a1_m
    if (cos(th) <= (-0.005d0)) then
        tmp = (-a2_m * (a2_m / sqrt(2.0d0))) + t_1
    else
        tmp = (sqrt(((a2_m * a2_m) / 2.0d0)) * a2_m) + t_1
    end if
    code = tmp
end function
a2_m = Math.abs(a2);
a1_m = Math.abs(a1);
assert a1_m < a2_m && a2_m < th;
public static double code(double a1_m, double a2_m, double th) {
	double t_1 = (a1_m / Math.sqrt(2.0)) * a1_m;
	double tmp;
	if (Math.cos(th) <= -0.005) {
		tmp = (-a2_m * (a2_m / Math.sqrt(2.0))) + t_1;
	} else {
		tmp = (Math.sqrt(((a2_m * a2_m) / 2.0)) * a2_m) + t_1;
	}
	return tmp;
}
a2_m = math.fabs(a2)
a1_m = math.fabs(a1)
[a1_m, a2_m, th] = sort([a1_m, a2_m, th])
def code(a1_m, a2_m, th):
	t_1 = (a1_m / math.sqrt(2.0)) * a1_m
	tmp = 0
	if math.cos(th) <= -0.005:
		tmp = (-a2_m * (a2_m / math.sqrt(2.0))) + t_1
	else:
		tmp = (math.sqrt(((a2_m * a2_m) / 2.0)) * a2_m) + t_1
	return tmp
a2_m = abs(a2)
a1_m = abs(a1)
a1_m, a2_m, th = sort([a1_m, a2_m, th])
function code(a1_m, a2_m, th)
	t_1 = Float64(Float64(a1_m / sqrt(2.0)) * a1_m)
	tmp = 0.0
	if (cos(th) <= -0.005)
		tmp = Float64(Float64(Float64(-a2_m) * Float64(a2_m / sqrt(2.0))) + t_1);
	else
		tmp = Float64(Float64(sqrt(Float64(Float64(a2_m * a2_m) / 2.0)) * a2_m) + t_1);
	end
	return tmp
end
a2_m = abs(a2);
a1_m = abs(a1);
a1_m, a2_m, th = num2cell(sort([a1_m, a2_m, th])){:}
function tmp_2 = code(a1_m, a2_m, th)
	t_1 = (a1_m / sqrt(2.0)) * a1_m;
	tmp = 0.0;
	if (cos(th) <= -0.005)
		tmp = (-a2_m * (a2_m / sqrt(2.0))) + t_1;
	else
		tmp = (sqrt(((a2_m * a2_m) / 2.0)) * a2_m) + t_1;
	end
	tmp_2 = tmp;
end
a2_m = N[Abs[a2], $MachinePrecision]
a1_m = N[Abs[a1], $MachinePrecision]
NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
code[a1$95$m_, a2$95$m_, th_] := Block[{t$95$1 = N[(N[(a1$95$m / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * a1$95$m), $MachinePrecision]}, If[LessEqual[N[Cos[th], $MachinePrecision], -0.005], N[(N[((-a2$95$m) * N[(a2$95$m / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision], N[(N[(N[Sqrt[N[(N[(a2$95$m * a2$95$m), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision] * a2$95$m), $MachinePrecision] + t$95$1), $MachinePrecision]]]
\begin{array}{l}
a2_m = \left|a2\right|
\\
a1_m = \left|a1\right|
\\
[a1_m, a2_m, th] = \mathsf{sort}([a1_m, a2_m, th])\\
\\
\begin{array}{l}
t_1 := \frac{a1\_m}{\sqrt{2}} \cdot a1\_m\\
\mathbf{if}\;\cos th \leq -0.005:\\
\;\;\;\;\left(-a2\_m\right) \cdot \frac{a2\_m}{\sqrt{2}} + t\_1\\

\mathbf{else}:\\
\;\;\;\;\sqrt{\frac{a2\_m \cdot a2\_m}{2}} \cdot a2\_m + t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (cos.f64 th) < -0.0050000000000000001

    1. Initial program 99.6%

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

      \[\leadsto \color{blue}{\frac{{a1}^{2}}{\sqrt{2}}} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    4. Step-by-step derivation
      1. unpow2N/A

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

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

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

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

        \[\leadsto \color{blue}{\frac{a1}{\sqrt{2}}} \cdot a1 + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      6. lower-sqrt.f6455.6

        \[\leadsto \frac{a1}{\color{blue}{\sqrt{2}}} \cdot a1 + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    5. Applied rewrites55.6%

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

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

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

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

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

        \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + a2 \cdot \color{blue}{\frac{a2}{\sqrt{2}}} \]
      5. lower-sqrt.f648.7

        \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + a2 \cdot \frac{a2}{\color{blue}{\sqrt{2}}} \]
    8. Applied rewrites8.7%

      \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \color{blue}{a2 \cdot \frac{a2}{\sqrt{2}}} \]
    9. Step-by-step derivation
      1. Applied rewrites31.0%

        \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + a2 \cdot \frac{a2}{\color{blue}{-\sqrt{2}}} \]

      if -0.0050000000000000001 < (cos.f64 th)

      1. Initial program 99.6%

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

        \[\leadsto \color{blue}{\frac{{a1}^{2}}{\sqrt{2}}} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      4. Step-by-step derivation
        1. unpow2N/A

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

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

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

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

          \[\leadsto \color{blue}{\frac{a1}{\sqrt{2}}} \cdot a1 + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
        6. lower-sqrt.f6491.6

          \[\leadsto \frac{a1}{\color{blue}{\sqrt{2}}} \cdot a1 + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      5. Applied rewrites91.6%

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

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

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

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

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

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + a2 \cdot \color{blue}{\frac{a2}{\sqrt{2}}} \]
        5. lower-sqrt.f6483.3

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + a2 \cdot \frac{a2}{\color{blue}{\sqrt{2}}} \]
      8. Applied rewrites83.3%

        \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \color{blue}{a2 \cdot \frac{a2}{\sqrt{2}}} \]
      9. Step-by-step derivation
        1. Applied rewrites58.4%

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + a2 \cdot \sqrt{\frac{a2 \cdot a2}{2}} \]
      10. Recombined 2 regimes into one program.
      11. Final simplification51.5%

        \[\leadsto \begin{array}{l} \mathbf{if}\;\cos th \leq -0.005:\\ \;\;\;\;\left(-a2\right) \cdot \frac{a2}{\sqrt{2}} + \frac{a1}{\sqrt{2}} \cdot a1\\ \mathbf{else}:\\ \;\;\;\;\sqrt{\frac{a2 \cdot a2}{2}} \cdot a2 + \frac{a1}{\sqrt{2}} \cdot a1\\ \end{array} \]
      12. Add Preprocessing

      Alternative 5: 97.7% accurate, 1.6× speedup?

      \[\begin{array}{l} a2_m = \left|a2\right| \\ a1_m = \left|a1\right| \\ [a1_m, a2_m, th] = \mathsf{sort}([a1_m, a2_m, th])\\ \\ \sqrt{\frac{a2\_m \cdot a2\_m}{2}} \cdot \left(a2\_m \cdot \cos th\right) + \frac{a1\_m}{\sqrt{2}} \cdot a1\_m \end{array} \]
      a2_m = (fabs.f64 a2)
      a1_m = (fabs.f64 a1)
      NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
      (FPCore (a1_m a2_m th)
       :precision binary64
       (+
        (* (sqrt (/ (* a2_m a2_m) 2.0)) (* a2_m (cos th)))
        (* (/ a1_m (sqrt 2.0)) a1_m)))
      a2_m = fabs(a2);
      a1_m = fabs(a1);
      assert(a1_m < a2_m && a2_m < th);
      double code(double a1_m, double a2_m, double th) {
      	return (sqrt(((a2_m * a2_m) / 2.0)) * (a2_m * cos(th))) + ((a1_m / sqrt(2.0)) * a1_m);
      }
      
      a2_m = abs(a2)
      a1_m = abs(a1)
      NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
      real(8) function code(a1_m, a2_m, th)
          real(8), intent (in) :: a1_m
          real(8), intent (in) :: a2_m
          real(8), intent (in) :: th
          code = (sqrt(((a2_m * a2_m) / 2.0d0)) * (a2_m * cos(th))) + ((a1_m / sqrt(2.0d0)) * a1_m)
      end function
      
      a2_m = Math.abs(a2);
      a1_m = Math.abs(a1);
      assert a1_m < a2_m && a2_m < th;
      public static double code(double a1_m, double a2_m, double th) {
      	return (Math.sqrt(((a2_m * a2_m) / 2.0)) * (a2_m * Math.cos(th))) + ((a1_m / Math.sqrt(2.0)) * a1_m);
      }
      
      a2_m = math.fabs(a2)
      a1_m = math.fabs(a1)
      [a1_m, a2_m, th] = sort([a1_m, a2_m, th])
      def code(a1_m, a2_m, th):
      	return (math.sqrt(((a2_m * a2_m) / 2.0)) * (a2_m * math.cos(th))) + ((a1_m / math.sqrt(2.0)) * a1_m)
      
      a2_m = abs(a2)
      a1_m = abs(a1)
      a1_m, a2_m, th = sort([a1_m, a2_m, th])
      function code(a1_m, a2_m, th)
      	return Float64(Float64(sqrt(Float64(Float64(a2_m * a2_m) / 2.0)) * Float64(a2_m * cos(th))) + Float64(Float64(a1_m / sqrt(2.0)) * a1_m))
      end
      
      a2_m = abs(a2);
      a1_m = abs(a1);
      a1_m, a2_m, th = num2cell(sort([a1_m, a2_m, th])){:}
      function tmp = code(a1_m, a2_m, th)
      	tmp = (sqrt(((a2_m * a2_m) / 2.0)) * (a2_m * cos(th))) + ((a1_m / sqrt(2.0)) * a1_m);
      end
      
      a2_m = N[Abs[a2], $MachinePrecision]
      a1_m = N[Abs[a1], $MachinePrecision]
      NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
      code[a1$95$m_, a2$95$m_, th_] := N[(N[(N[Sqrt[N[(N[(a2$95$m * a2$95$m), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision] * N[(a2$95$m * N[Cos[th], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(a1$95$m / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * a1$95$m), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      a2_m = \left|a2\right|
      \\
      a1_m = \left|a1\right|
      \\
      [a1_m, a2_m, th] = \mathsf{sort}([a1_m, a2_m, th])\\
      \\
      \sqrt{\frac{a2\_m \cdot a2\_m}{2}} \cdot \left(a2\_m \cdot \cos th\right) + \frac{a1\_m}{\sqrt{2}} \cdot a1\_m
      \end{array}
      
      Derivation
      1. Initial program 99.6%

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

        \[\leadsto \color{blue}{\frac{{a1}^{2}}{\sqrt{2}}} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      4. Step-by-step derivation
        1. unpow2N/A

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

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

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

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

          \[\leadsto \color{blue}{\frac{a1}{\sqrt{2}}} \cdot a1 + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
        6. lower-sqrt.f6482.5

          \[\leadsto \frac{a1}{\color{blue}{\sqrt{2}}} \cdot a1 + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      5. Applied rewrites82.5%

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

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

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

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

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

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

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \frac{a2 \cdot a2}{\frac{1}{\color{blue}{\frac{\cos th}{\sqrt{2}}}}} \]
        7. frac-2negN/A

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

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

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

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

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

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

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

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

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

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \frac{-a2}{\frac{\color{blue}{-1}}{\mathsf{neg}\left(\left(\mathsf{neg}\left(\cos th\right)\right)\right)}} \cdot \frac{a2}{\sqrt{2}} \]
        17. remove-double-negN/A

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \frac{-a2}{\frac{-1}{\color{blue}{\cos th}}} \cdot \frac{a2}{\sqrt{2}} \]
        18. lower-/.f64N/A

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \frac{-a2}{\color{blue}{\frac{-1}{\cos th}}} \cdot \frac{a2}{\sqrt{2}} \]
        19. lower-/.f6482.5

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \frac{-a2}{\frac{-1}{\cos th}} \cdot \color{blue}{\frac{a2}{\sqrt{2}}} \]
      7. Applied rewrites82.5%

        \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \color{blue}{\frac{-a2}{\frac{-1}{\cos th}} \cdot \frac{a2}{\sqrt{2}}} \]
      8. Step-by-step derivation
        1. lift-/.f64N/A

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \frac{-a2}{\frac{-1}{\cos th}} \cdot \color{blue}{\frac{a2}{\sqrt{2}}} \]
        2. unpow1N/A

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \frac{-a2}{\frac{-1}{\cos th}} \cdot \frac{\color{blue}{{a2}^{1}}}{\sqrt{2}} \]
        3. metadata-evalN/A

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \frac{-a2}{\frac{-1}{\cos th}} \cdot \frac{{a2}^{\color{blue}{\left(\frac{2}{2}\right)}}}{\sqrt{2}} \]
        4. sqrt-pow1N/A

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \frac{-a2}{\frac{-1}{\cos th}} \cdot \frac{\color{blue}{\sqrt{{a2}^{2}}}}{\sqrt{2}} \]
        5. pow2N/A

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

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \frac{-a2}{\frac{-1}{\cos th}} \cdot \frac{\sqrt{a2 \cdot a2}}{\color{blue}{\sqrt{2}}} \]
        7. sqrt-undivN/A

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

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

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \frac{-a2}{\frac{-1}{\cos th}} \cdot \sqrt{\color{blue}{\frac{a2 \cdot a2}{2}}} \]
        10. lower-*.f6456.5

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \frac{-a2}{\frac{-1}{\cos th}} \cdot \sqrt{\frac{\color{blue}{a2 \cdot a2}}{2}} \]
      9. Applied rewrites56.5%

        \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \frac{-a2}{\frac{-1}{\cos th}} \cdot \color{blue}{\sqrt{\frac{a2 \cdot a2}{2}}} \]
      10. Taylor expanded in a2 around 0

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

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

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \color{blue}{\left(\cos th \cdot a2\right)} \cdot \sqrt{\frac{a2 \cdot a2}{2}} \]
        3. lower-cos.f6456.5

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \left(\color{blue}{\cos th} \cdot a2\right) \cdot \sqrt{\frac{a2 \cdot a2}{2}} \]
      12. Applied rewrites56.5%

        \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \color{blue}{\left(\cos th \cdot a2\right)} \cdot \sqrt{\frac{a2 \cdot a2}{2}} \]
      13. Final simplification56.5%

        \[\leadsto \sqrt{\frac{a2 \cdot a2}{2}} \cdot \left(a2 \cdot \cos th\right) + \frac{a1}{\sqrt{2}} \cdot a1 \]
      14. Add Preprocessing

      Alternative 6: 78.1% accurate, 1.6× speedup?

      \[\begin{array}{l} a2_m = \left|a2\right| \\ a1_m = \left|a1\right| \\ [a1_m, a2_m, th] = \mathsf{sort}([a1_m, a2_m, th])\\ \\ \begin{array}{l} t_1 := \frac{a2\_m}{\sqrt{2}}\\ t_2 := \frac{a1\_m}{\sqrt{2}} \cdot a1\_m\\ \mathbf{if}\;\cos th \leq -5 \cdot 10^{-310}:\\ \;\;\;\;\left(-a2\_m\right) \cdot t\_1 + t\_2\\ \mathbf{else}:\\ \;\;\;\;t\_1 \cdot a2\_m + t\_2\\ \end{array} \end{array} \]
      a2_m = (fabs.f64 a2)
      a1_m = (fabs.f64 a1)
      NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
      (FPCore (a1_m a2_m th)
       :precision binary64
       (let* ((t_1 (/ a2_m (sqrt 2.0))) (t_2 (* (/ a1_m (sqrt 2.0)) a1_m)))
         (if (<= (cos th) -5e-310) (+ (* (- a2_m) t_1) t_2) (+ (* t_1 a2_m) t_2))))
      a2_m = fabs(a2);
      a1_m = fabs(a1);
      assert(a1_m < a2_m && a2_m < th);
      double code(double a1_m, double a2_m, double th) {
      	double t_1 = a2_m / sqrt(2.0);
      	double t_2 = (a1_m / sqrt(2.0)) * a1_m;
      	double tmp;
      	if (cos(th) <= -5e-310) {
      		tmp = (-a2_m * t_1) + t_2;
      	} else {
      		tmp = (t_1 * a2_m) + t_2;
      	}
      	return tmp;
      }
      
      a2_m = abs(a2)
      a1_m = abs(a1)
      NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
      real(8) function code(a1_m, a2_m, th)
          real(8), intent (in) :: a1_m
          real(8), intent (in) :: a2_m
          real(8), intent (in) :: th
          real(8) :: t_1
          real(8) :: t_2
          real(8) :: tmp
          t_1 = a2_m / sqrt(2.0d0)
          t_2 = (a1_m / sqrt(2.0d0)) * a1_m
          if (cos(th) <= (-5d-310)) then
              tmp = (-a2_m * t_1) + t_2
          else
              tmp = (t_1 * a2_m) + t_2
          end if
          code = tmp
      end function
      
      a2_m = Math.abs(a2);
      a1_m = Math.abs(a1);
      assert a1_m < a2_m && a2_m < th;
      public static double code(double a1_m, double a2_m, double th) {
      	double t_1 = a2_m / Math.sqrt(2.0);
      	double t_2 = (a1_m / Math.sqrt(2.0)) * a1_m;
      	double tmp;
      	if (Math.cos(th) <= -5e-310) {
      		tmp = (-a2_m * t_1) + t_2;
      	} else {
      		tmp = (t_1 * a2_m) + t_2;
      	}
      	return tmp;
      }
      
      a2_m = math.fabs(a2)
      a1_m = math.fabs(a1)
      [a1_m, a2_m, th] = sort([a1_m, a2_m, th])
      def code(a1_m, a2_m, th):
      	t_1 = a2_m / math.sqrt(2.0)
      	t_2 = (a1_m / math.sqrt(2.0)) * a1_m
      	tmp = 0
      	if math.cos(th) <= -5e-310:
      		tmp = (-a2_m * t_1) + t_2
      	else:
      		tmp = (t_1 * a2_m) + t_2
      	return tmp
      
      a2_m = abs(a2)
      a1_m = abs(a1)
      a1_m, a2_m, th = sort([a1_m, a2_m, th])
      function code(a1_m, a2_m, th)
      	t_1 = Float64(a2_m / sqrt(2.0))
      	t_2 = Float64(Float64(a1_m / sqrt(2.0)) * a1_m)
      	tmp = 0.0
      	if (cos(th) <= -5e-310)
      		tmp = Float64(Float64(Float64(-a2_m) * t_1) + t_2);
      	else
      		tmp = Float64(Float64(t_1 * a2_m) + t_2);
      	end
      	return tmp
      end
      
      a2_m = abs(a2);
      a1_m = abs(a1);
      a1_m, a2_m, th = num2cell(sort([a1_m, a2_m, th])){:}
      function tmp_2 = code(a1_m, a2_m, th)
      	t_1 = a2_m / sqrt(2.0);
      	t_2 = (a1_m / sqrt(2.0)) * a1_m;
      	tmp = 0.0;
      	if (cos(th) <= -5e-310)
      		tmp = (-a2_m * t_1) + t_2;
      	else
      		tmp = (t_1 * a2_m) + t_2;
      	end
      	tmp_2 = tmp;
      end
      
      a2_m = N[Abs[a2], $MachinePrecision]
      a1_m = N[Abs[a1], $MachinePrecision]
      NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
      code[a1$95$m_, a2$95$m_, th_] := Block[{t$95$1 = N[(a2$95$m / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(a1$95$m / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * a1$95$m), $MachinePrecision]}, If[LessEqual[N[Cos[th], $MachinePrecision], -5e-310], N[(N[((-a2$95$m) * t$95$1), $MachinePrecision] + t$95$2), $MachinePrecision], N[(N[(t$95$1 * a2$95$m), $MachinePrecision] + t$95$2), $MachinePrecision]]]]
      
      \begin{array}{l}
      a2_m = \left|a2\right|
      \\
      a1_m = \left|a1\right|
      \\
      [a1_m, a2_m, th] = \mathsf{sort}([a1_m, a2_m, th])\\
      \\
      \begin{array}{l}
      t_1 := \frac{a2\_m}{\sqrt{2}}\\
      t_2 := \frac{a1\_m}{\sqrt{2}} \cdot a1\_m\\
      \mathbf{if}\;\cos th \leq -5 \cdot 10^{-310}:\\
      \;\;\;\;\left(-a2\_m\right) \cdot t\_1 + t\_2\\
      
      \mathbf{else}:\\
      \;\;\;\;t\_1 \cdot a2\_m + t\_2\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (cos.f64 th) < -4.999999999999985e-310

        1. Initial program 99.6%

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

          \[\leadsto \color{blue}{\frac{{a1}^{2}}{\sqrt{2}}} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
        4. Step-by-step derivation
          1. unpow2N/A

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

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

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

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

            \[\leadsto \color{blue}{\frac{a1}{\sqrt{2}}} \cdot a1 + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
          6. lower-sqrt.f6455.6

            \[\leadsto \frac{a1}{\color{blue}{\sqrt{2}}} \cdot a1 + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
        5. Applied rewrites55.6%

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

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

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

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

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

            \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + a2 \cdot \color{blue}{\frac{a2}{\sqrt{2}}} \]
          5. lower-sqrt.f648.7

            \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + a2 \cdot \frac{a2}{\color{blue}{\sqrt{2}}} \]
        8. Applied rewrites8.7%

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \color{blue}{a2 \cdot \frac{a2}{\sqrt{2}}} \]
        9. Step-by-step derivation
          1. Applied rewrites31.0%

            \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + a2 \cdot \frac{a2}{\color{blue}{-\sqrt{2}}} \]

          if -4.999999999999985e-310 < (cos.f64 th)

          1. Initial program 99.6%

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

            \[\leadsto \color{blue}{\frac{{a1}^{2}}{\sqrt{2}}} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
          4. Step-by-step derivation
            1. unpow2N/A

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

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

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

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

              \[\leadsto \color{blue}{\frac{a1}{\sqrt{2}}} \cdot a1 + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
            6. lower-sqrt.f6491.6

              \[\leadsto \frac{a1}{\color{blue}{\sqrt{2}}} \cdot a1 + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
          5. Applied rewrites91.6%

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

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

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

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

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

              \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + a2 \cdot \color{blue}{\frac{a2}{\sqrt{2}}} \]
            5. lower-sqrt.f6483.3

              \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + a2 \cdot \frac{a2}{\color{blue}{\sqrt{2}}} \]
          8. Applied rewrites83.3%

            \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \color{blue}{a2 \cdot \frac{a2}{\sqrt{2}}} \]
        10. Recombined 2 regimes into one program.
        11. Final simplification70.1%

          \[\leadsto \begin{array}{l} \mathbf{if}\;\cos th \leq -5 \cdot 10^{-310}:\\ \;\;\;\;\left(-a2\right) \cdot \frac{a2}{\sqrt{2}} + \frac{a1}{\sqrt{2}} \cdot a1\\ \mathbf{else}:\\ \;\;\;\;\frac{a2}{\sqrt{2}} \cdot a2 + \frac{a1}{\sqrt{2}} \cdot a1\\ \end{array} \]
        12. Add Preprocessing

        Alternative 7: 97.6% accurate, 1.7× speedup?

        \[\begin{array}{l} a2_m = \left|a2\right| \\ a1_m = \left|a1\right| \\ [a1_m, a2_m, th] = \mathsf{sort}([a1_m, a2_m, th])\\ \\ \left(\frac{a2\_m}{\sqrt{2}} \cdot \cos th\right) \cdot a2\_m + \frac{a1\_m}{\sqrt{2}} \cdot a1\_m \end{array} \]
        a2_m = (fabs.f64 a2)
        a1_m = (fabs.f64 a1)
        NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
        (FPCore (a1_m a2_m th)
         :precision binary64
         (+ (* (* (/ a2_m (sqrt 2.0)) (cos th)) a2_m) (* (/ a1_m (sqrt 2.0)) a1_m)))
        a2_m = fabs(a2);
        a1_m = fabs(a1);
        assert(a1_m < a2_m && a2_m < th);
        double code(double a1_m, double a2_m, double th) {
        	return (((a2_m / sqrt(2.0)) * cos(th)) * a2_m) + ((a1_m / sqrt(2.0)) * a1_m);
        }
        
        a2_m = abs(a2)
        a1_m = abs(a1)
        NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
        real(8) function code(a1_m, a2_m, th)
            real(8), intent (in) :: a1_m
            real(8), intent (in) :: a2_m
            real(8), intent (in) :: th
            code = (((a2_m / sqrt(2.0d0)) * cos(th)) * a2_m) + ((a1_m / sqrt(2.0d0)) * a1_m)
        end function
        
        a2_m = Math.abs(a2);
        a1_m = Math.abs(a1);
        assert a1_m < a2_m && a2_m < th;
        public static double code(double a1_m, double a2_m, double th) {
        	return (((a2_m / Math.sqrt(2.0)) * Math.cos(th)) * a2_m) + ((a1_m / Math.sqrt(2.0)) * a1_m);
        }
        
        a2_m = math.fabs(a2)
        a1_m = math.fabs(a1)
        [a1_m, a2_m, th] = sort([a1_m, a2_m, th])
        def code(a1_m, a2_m, th):
        	return (((a2_m / math.sqrt(2.0)) * math.cos(th)) * a2_m) + ((a1_m / math.sqrt(2.0)) * a1_m)
        
        a2_m = abs(a2)
        a1_m = abs(a1)
        a1_m, a2_m, th = sort([a1_m, a2_m, th])
        function code(a1_m, a2_m, th)
        	return Float64(Float64(Float64(Float64(a2_m / sqrt(2.0)) * cos(th)) * a2_m) + Float64(Float64(a1_m / sqrt(2.0)) * a1_m))
        end
        
        a2_m = abs(a2);
        a1_m = abs(a1);
        a1_m, a2_m, th = num2cell(sort([a1_m, a2_m, th])){:}
        function tmp = code(a1_m, a2_m, th)
        	tmp = (((a2_m / sqrt(2.0)) * cos(th)) * a2_m) + ((a1_m / sqrt(2.0)) * a1_m);
        end
        
        a2_m = N[Abs[a2], $MachinePrecision]
        a1_m = N[Abs[a1], $MachinePrecision]
        NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
        code[a1$95$m_, a2$95$m_, th_] := N[(N[(N[(N[(a2$95$m / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision] * a2$95$m), $MachinePrecision] + N[(N[(a1$95$m / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * a1$95$m), $MachinePrecision]), $MachinePrecision]
        
        \begin{array}{l}
        a2_m = \left|a2\right|
        \\
        a1_m = \left|a1\right|
        \\
        [a1_m, a2_m, th] = \mathsf{sort}([a1_m, a2_m, th])\\
        \\
        \left(\frac{a2\_m}{\sqrt{2}} \cdot \cos th\right) \cdot a2\_m + \frac{a1\_m}{\sqrt{2}} \cdot a1\_m
        \end{array}
        
        Derivation
        1. Initial program 99.6%

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

          \[\leadsto \color{blue}{\frac{{a1}^{2}}{\sqrt{2}}} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
        4. Step-by-step derivation
          1. unpow2N/A

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

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

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

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

            \[\leadsto \color{blue}{\frac{a1}{\sqrt{2}}} \cdot a1 + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
          6. lower-sqrt.f6482.5

            \[\leadsto \frac{a1}{\color{blue}{\sqrt{2}}} \cdot a1 + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
        5. Applied rewrites82.5%

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

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

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

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \color{blue}{\left(\cos th \cdot \frac{a2}{\sqrt{2}}\right)} \cdot a2 \]
          14. lower-/.f6482.5

            \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \left(\cos th \cdot \color{blue}{\frac{a2}{\sqrt{2}}}\right) \cdot a2 \]
        7. Applied rewrites82.5%

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \color{blue}{\left(\cos th \cdot \frac{a2}{\sqrt{2}}\right) \cdot a2} \]
        8. Final simplification82.5%

          \[\leadsto \left(\frac{a2}{\sqrt{2}} \cdot \cos th\right) \cdot a2 + \frac{a1}{\sqrt{2}} \cdot a1 \]
        9. Add Preprocessing

        Alternative 8: 97.6% accurate, 1.7× speedup?

        \[\begin{array}{l} a2_m = \left|a2\right| \\ a1_m = \left|a1\right| \\ [a1_m, a2_m, th] = \mathsf{sort}([a1_m, a2_m, th])\\ \\ \left(\frac{a2\_m}{\sqrt{2}} \cdot a2\_m\right) \cdot \cos th + \frac{a1\_m}{\sqrt{2}} \cdot a1\_m \end{array} \]
        a2_m = (fabs.f64 a2)
        a1_m = (fabs.f64 a1)
        NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
        (FPCore (a1_m a2_m th)
         :precision binary64
         (+ (* (* (/ a2_m (sqrt 2.0)) a2_m) (cos th)) (* (/ a1_m (sqrt 2.0)) a1_m)))
        a2_m = fabs(a2);
        a1_m = fabs(a1);
        assert(a1_m < a2_m && a2_m < th);
        double code(double a1_m, double a2_m, double th) {
        	return (((a2_m / sqrt(2.0)) * a2_m) * cos(th)) + ((a1_m / sqrt(2.0)) * a1_m);
        }
        
        a2_m = abs(a2)
        a1_m = abs(a1)
        NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
        real(8) function code(a1_m, a2_m, th)
            real(8), intent (in) :: a1_m
            real(8), intent (in) :: a2_m
            real(8), intent (in) :: th
            code = (((a2_m / sqrt(2.0d0)) * a2_m) * cos(th)) + ((a1_m / sqrt(2.0d0)) * a1_m)
        end function
        
        a2_m = Math.abs(a2);
        a1_m = Math.abs(a1);
        assert a1_m < a2_m && a2_m < th;
        public static double code(double a1_m, double a2_m, double th) {
        	return (((a2_m / Math.sqrt(2.0)) * a2_m) * Math.cos(th)) + ((a1_m / Math.sqrt(2.0)) * a1_m);
        }
        
        a2_m = math.fabs(a2)
        a1_m = math.fabs(a1)
        [a1_m, a2_m, th] = sort([a1_m, a2_m, th])
        def code(a1_m, a2_m, th):
        	return (((a2_m / math.sqrt(2.0)) * a2_m) * math.cos(th)) + ((a1_m / math.sqrt(2.0)) * a1_m)
        
        a2_m = abs(a2)
        a1_m = abs(a1)
        a1_m, a2_m, th = sort([a1_m, a2_m, th])
        function code(a1_m, a2_m, th)
        	return Float64(Float64(Float64(Float64(a2_m / sqrt(2.0)) * a2_m) * cos(th)) + Float64(Float64(a1_m / sqrt(2.0)) * a1_m))
        end
        
        a2_m = abs(a2);
        a1_m = abs(a1);
        a1_m, a2_m, th = num2cell(sort([a1_m, a2_m, th])){:}
        function tmp = code(a1_m, a2_m, th)
        	tmp = (((a2_m / sqrt(2.0)) * a2_m) * cos(th)) + ((a1_m / sqrt(2.0)) * a1_m);
        end
        
        a2_m = N[Abs[a2], $MachinePrecision]
        a1_m = N[Abs[a1], $MachinePrecision]
        NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
        code[a1$95$m_, a2$95$m_, th_] := N[(N[(N[(N[(a2$95$m / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * a2$95$m), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision] + N[(N[(a1$95$m / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * a1$95$m), $MachinePrecision]), $MachinePrecision]
        
        \begin{array}{l}
        a2_m = \left|a2\right|
        \\
        a1_m = \left|a1\right|
        \\
        [a1_m, a2_m, th] = \mathsf{sort}([a1_m, a2_m, th])\\
        \\
        \left(\frac{a2\_m}{\sqrt{2}} \cdot a2\_m\right) \cdot \cos th + \frac{a1\_m}{\sqrt{2}} \cdot a1\_m
        \end{array}
        
        Derivation
        1. Initial program 99.6%

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

          \[\leadsto \color{blue}{\frac{{a1}^{2}}{\sqrt{2}}} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
        4. Step-by-step derivation
          1. unpow2N/A

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

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

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

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

            \[\leadsto \color{blue}{\frac{a1}{\sqrt{2}}} \cdot a1 + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
          6. lower-sqrt.f6482.5

            \[\leadsto \frac{a1}{\color{blue}{\sqrt{2}}} \cdot a1 + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
        5. Applied rewrites82.5%

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

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

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

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

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

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

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

            \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \frac{a2 \cdot a2}{\color{blue}{\frac{\sqrt{2}}{\cos th}}} \]
          8. associate-/r/N/A

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

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

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

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

            \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \color{blue}{\left(a2 \cdot \frac{a2}{\sqrt{2}}\right)} \cdot \cos th \]
          13. lower-/.f6482.5

            \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \left(a2 \cdot \color{blue}{\frac{a2}{\sqrt{2}}}\right) \cdot \cos th \]
        7. Applied rewrites82.5%

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \color{blue}{\left(a2 \cdot \frac{a2}{\sqrt{2}}\right) \cdot \cos th} \]
        8. Final simplification82.5%

          \[\leadsto \left(\frac{a2}{\sqrt{2}} \cdot a2\right) \cdot \cos th + \frac{a1}{\sqrt{2}} \cdot a1 \]
        9. Add Preprocessing

        Alternative 9: 66.4% accurate, 4.8× speedup?

        \[\begin{array}{l} a2_m = \left|a2\right| \\ a1_m = \left|a1\right| \\ [a1_m, a2_m, th] = \mathsf{sort}([a1_m, a2_m, th])\\ \\ \frac{a2\_m}{\sqrt{2}} \cdot a2\_m + \frac{a1\_m}{\sqrt{2}} \cdot a1\_m \end{array} \]
        a2_m = (fabs.f64 a2)
        a1_m = (fabs.f64 a1)
        NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
        (FPCore (a1_m a2_m th)
         :precision binary64
         (+ (* (/ a2_m (sqrt 2.0)) a2_m) (* (/ a1_m (sqrt 2.0)) a1_m)))
        a2_m = fabs(a2);
        a1_m = fabs(a1);
        assert(a1_m < a2_m && a2_m < th);
        double code(double a1_m, double a2_m, double th) {
        	return ((a2_m / sqrt(2.0)) * a2_m) + ((a1_m / sqrt(2.0)) * a1_m);
        }
        
        a2_m = abs(a2)
        a1_m = abs(a1)
        NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
        real(8) function code(a1_m, a2_m, th)
            real(8), intent (in) :: a1_m
            real(8), intent (in) :: a2_m
            real(8), intent (in) :: th
            code = ((a2_m / sqrt(2.0d0)) * a2_m) + ((a1_m / sqrt(2.0d0)) * a1_m)
        end function
        
        a2_m = Math.abs(a2);
        a1_m = Math.abs(a1);
        assert a1_m < a2_m && a2_m < th;
        public static double code(double a1_m, double a2_m, double th) {
        	return ((a2_m / Math.sqrt(2.0)) * a2_m) + ((a1_m / Math.sqrt(2.0)) * a1_m);
        }
        
        a2_m = math.fabs(a2)
        a1_m = math.fabs(a1)
        [a1_m, a2_m, th] = sort([a1_m, a2_m, th])
        def code(a1_m, a2_m, th):
        	return ((a2_m / math.sqrt(2.0)) * a2_m) + ((a1_m / math.sqrt(2.0)) * a1_m)
        
        a2_m = abs(a2)
        a1_m = abs(a1)
        a1_m, a2_m, th = sort([a1_m, a2_m, th])
        function code(a1_m, a2_m, th)
        	return Float64(Float64(Float64(a2_m / sqrt(2.0)) * a2_m) + Float64(Float64(a1_m / sqrt(2.0)) * a1_m))
        end
        
        a2_m = abs(a2);
        a1_m = abs(a1);
        a1_m, a2_m, th = num2cell(sort([a1_m, a2_m, th])){:}
        function tmp = code(a1_m, a2_m, th)
        	tmp = ((a2_m / sqrt(2.0)) * a2_m) + ((a1_m / sqrt(2.0)) * a1_m);
        end
        
        a2_m = N[Abs[a2], $MachinePrecision]
        a1_m = N[Abs[a1], $MachinePrecision]
        NOTE: a1_m, a2_m, and th should be sorted in increasing order before calling this function.
        code[a1$95$m_, a2$95$m_, th_] := N[(N[(N[(a2$95$m / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * a2$95$m), $MachinePrecision] + N[(N[(a1$95$m / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * a1$95$m), $MachinePrecision]), $MachinePrecision]
        
        \begin{array}{l}
        a2_m = \left|a2\right|
        \\
        a1_m = \left|a1\right|
        \\
        [a1_m, a2_m, th] = \mathsf{sort}([a1_m, a2_m, th])\\
        \\
        \frac{a2\_m}{\sqrt{2}} \cdot a2\_m + \frac{a1\_m}{\sqrt{2}} \cdot a1\_m
        \end{array}
        
        Derivation
        1. Initial program 99.6%

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

          \[\leadsto \color{blue}{\frac{{a1}^{2}}{\sqrt{2}}} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
        4. Step-by-step derivation
          1. unpow2N/A

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

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

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

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

            \[\leadsto \color{blue}{\frac{a1}{\sqrt{2}}} \cdot a1 + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
          6. lower-sqrt.f6482.5

            \[\leadsto \frac{a1}{\color{blue}{\sqrt{2}}} \cdot a1 + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
        5. Applied rewrites82.5%

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

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

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

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

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

            \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + a2 \cdot \color{blue}{\frac{a2}{\sqrt{2}}} \]
          5. lower-sqrt.f6464.4

            \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + a2 \cdot \frac{a2}{\color{blue}{\sqrt{2}}} \]
        8. Applied rewrites64.4%

          \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 + \color{blue}{a2 \cdot \frac{a2}{\sqrt{2}}} \]
        9. Final simplification64.4%

          \[\leadsto \frac{a2}{\sqrt{2}} \cdot a2 + \frac{a1}{\sqrt{2}} \cdot a1 \]
        10. Add Preprocessing

        Reproduce

        ?
        herbie shell --seed 2024312 
        (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))))