Migdal et al, Equation (64)

Percentage Accurate: 99.5% → 99.5%
Time: 7.3s
Alternatives: 13
Speedup: 1.9×

Specification

?
\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{\cos th}{\sqrt{2}}\\ t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right) \end{array} \end{array} \]
(FPCore (a1 a2 th)
 :precision binary64
 (let* ((t_1 (/ (cos th) (sqrt 2.0))))
   (+ (* t_1 (* a1 a1)) (* t_1 (* a2 a2)))))
double code(double a1, double a2, double th) {
	double t_1 = cos(th) / sqrt(2.0);
	return (t_1 * (a1 * a1)) + (t_1 * (a2 * a2));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

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

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

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 13 alternatives:

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

Initial Program: 99.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{\cos th}{\sqrt{2}}\\ t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right) \end{array} \end{array} \]
(FPCore (a1 a2 th)
 :precision binary64
 (let* ((t_1 (/ (cos th) (sqrt 2.0))))
   (+ (* t_1 (* a1 a1)) (* t_1 (* a2 a2)))))
double code(double a1, double a2, double th) {
	double t_1 = cos(th) / sqrt(2.0);
	return (t_1 * (a1 * a1)) + (t_1 * (a2 * a2));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(a1, a2, th)
use fmin_fmax_functions
    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, 1.0× speedup?

\[\begin{array}{l} a2_m = \left|a2\right| \\ [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\ \\ \mathsf{fma}\left(\cos th, \frac{a2\_m \cdot a2\_m}{\sqrt{2}}, \left(a1 \cdot a1\right) \cdot \frac{\cos th}{\sqrt{2}}\right) \end{array} \]
a2_m = (fabs.f64 a2)
NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
(FPCore (a1 a2_m th)
 :precision binary64
 (fma
  (cos th)
  (/ (* a2_m a2_m) (sqrt 2.0))
  (* (* a1 a1) (/ (cos th) (sqrt 2.0)))))
a2_m = fabs(a2);
assert(a1 < a2_m && a2_m < th);
double code(double a1, double a2_m, double th) {
	return fma(cos(th), ((a2_m * a2_m) / sqrt(2.0)), ((a1 * a1) * (cos(th) / sqrt(2.0))));
}
a2_m = abs(a2)
a1, a2_m, th = sort([a1, a2_m, th])
function code(a1, a2_m, th)
	return fma(cos(th), Float64(Float64(a2_m * a2_m) / sqrt(2.0)), Float64(Float64(a1 * a1) * Float64(cos(th) / sqrt(2.0))))
end
a2_m = N[Abs[a2], $MachinePrecision]
NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
code[a1_, a2$95$m_, th_] := N[(N[Cos[th], $MachinePrecision] * N[(N[(a2$95$m * a2$95$m), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] + N[(N[(a1 * a1), $MachinePrecision] * N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
a2_m = \left|a2\right|
\\
[a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\
\\
\mathsf{fma}\left(\cos th, \frac{a2\_m \cdot a2\_m}{\sqrt{2}}, \left(a1 \cdot a1\right) \cdot \frac{\cos th}{\sqrt{2}}\right)
\end{array}
Derivation
  1. Initial program 99.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

Alternative 2: 77.7% accurate, 0.8× speedup?

\[\begin{array}{l} a2_m = \left|a2\right| \\ [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\ \\ \begin{array}{l} t_1 := \mathsf{fma}\left(a2\_m, a2\_m, a1 \cdot a1\right)\\ t_2 := \frac{\cos th}{\sqrt{2}}\\ \mathbf{if}\;t\_2 \cdot \left(a1 \cdot a1\right) + t\_2 \cdot \left(a2\_m \cdot a2\_m\right) \leq -2 \cdot 10^{-113}:\\ \;\;\;\;\left(t\_1 \cdot \sqrt{2}\right) \cdot \mathsf{fma}\left(th \cdot th, -0.25, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{t\_1}{\sqrt{2}}\\ \end{array} \end{array} \]
a2_m = (fabs.f64 a2)
NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
(FPCore (a1 a2_m th)
 :precision binary64
 (let* ((t_1 (fma a2_m a2_m (* a1 a1))) (t_2 (/ (cos th) (sqrt 2.0))))
   (if (<= (+ (* t_2 (* a1 a1)) (* t_2 (* a2_m a2_m))) -2e-113)
     (* (* t_1 (sqrt 2.0)) (fma (* th th) -0.25 0.5))
     (/ t_1 (sqrt 2.0)))))
a2_m = fabs(a2);
assert(a1 < a2_m && a2_m < th);
double code(double a1, double a2_m, double th) {
	double t_1 = fma(a2_m, a2_m, (a1 * a1));
	double t_2 = cos(th) / sqrt(2.0);
	double tmp;
	if (((t_2 * (a1 * a1)) + (t_2 * (a2_m * a2_m))) <= -2e-113) {
		tmp = (t_1 * sqrt(2.0)) * fma((th * th), -0.25, 0.5);
	} else {
		tmp = t_1 / sqrt(2.0);
	}
	return tmp;
}
a2_m = abs(a2)
a1, a2_m, th = sort([a1, a2_m, th])
function code(a1, a2_m, th)
	t_1 = fma(a2_m, a2_m, Float64(a1 * a1))
	t_2 = Float64(cos(th) / sqrt(2.0))
	tmp = 0.0
	if (Float64(Float64(t_2 * Float64(a1 * a1)) + Float64(t_2 * Float64(a2_m * a2_m))) <= -2e-113)
		tmp = Float64(Float64(t_1 * sqrt(2.0)) * fma(Float64(th * th), -0.25, 0.5));
	else
		tmp = Float64(t_1 / sqrt(2.0));
	end
	return tmp
end
a2_m = N[Abs[a2], $MachinePrecision]
NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
code[a1_, a2$95$m_, th_] := Block[{t$95$1 = N[(a2$95$m * a2$95$m + N[(a1 * a1), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(t$95$2 * N[(a1 * a1), $MachinePrecision]), $MachinePrecision] + N[(t$95$2 * N[(a2$95$m * a2$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -2e-113], N[(N[(t$95$1 * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[(N[(th * th), $MachinePrecision] * -0.25 + 0.5), $MachinePrecision]), $MachinePrecision], N[(t$95$1 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}
a2_m = \left|a2\right|
\\
[a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\
\\
\begin{array}{l}
t_1 := \mathsf{fma}\left(a2\_m, a2\_m, a1 \cdot a1\right)\\
t_2 := \frac{\cos th}{\sqrt{2}}\\
\mathbf{if}\;t\_2 \cdot \left(a1 \cdot a1\right) + t\_2 \cdot \left(a2\_m \cdot a2\_m\right) \leq -2 \cdot 10^{-113}:\\
\;\;\;\;\left(t\_1 \cdot \sqrt{2}\right) \cdot \mathsf{fma}\left(th \cdot th, -0.25, 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{t\_1}{\sqrt{2}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a1 a1)) (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a2 a2))) < -1.99999999999999996e-113

    1. Initial program 99.5%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \color{blue}{\frac{-1}{4} \cdot \left({th}^{2} \cdot \left(\sqrt{2} \cdot \left({a1}^{2} + {a2}^{2}\right)\right)\right) + \frac{1}{2} \cdot \left(\sqrt{2} \cdot \left({a1}^{2} + {a2}^{2}\right)\right)} \]
    10. Step-by-step derivation
      1. Applied rewrites45.4%

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

      if -1.99999999999999996e-113 < (+.f64 (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a1 a1)) (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a2 a2)))

      1. Initial program 99.6%

        \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      2. Add Preprocessing
      3. 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. Applied rewrites84.1%

          \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}}} \]
      5. Recombined 2 regimes into one program.
      6. Final simplification75.8%

        \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \leq -2 \cdot 10^{-113}:\\ \;\;\;\;\left(\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \sqrt{2}\right) \cdot \mathsf{fma}\left(th \cdot th, -0.25, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}}\\ \end{array} \]
      7. Add Preprocessing

      Alternative 3: 99.6% accurate, 1.9× speedup?

      \[\begin{array}{l} a2_m = \left|a2\right| \\ [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\ \\ \frac{\cos th \cdot \mathsf{fma}\left(a2\_m, a2\_m, a1 \cdot a1\right)}{\sqrt{2}} \end{array} \]
      a2_m = (fabs.f64 a2)
      NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
      (FPCore (a1 a2_m th)
       :precision binary64
       (/ (* (cos th) (fma a2_m a2_m (* a1 a1))) (sqrt 2.0)))
      a2_m = fabs(a2);
      assert(a1 < a2_m && a2_m < th);
      double code(double a1, double a2_m, double th) {
      	return (cos(th) * fma(a2_m, a2_m, (a1 * a1))) / sqrt(2.0);
      }
      
      a2_m = abs(a2)
      a1, a2_m, th = sort([a1, a2_m, th])
      function code(a1, a2_m, th)
      	return Float64(Float64(cos(th) * fma(a2_m, a2_m, Float64(a1 * a1))) / sqrt(2.0))
      end
      
      a2_m = N[Abs[a2], $MachinePrecision]
      NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
      code[a1_, a2$95$m_, th_] := N[(N[(N[Cos[th], $MachinePrecision] * N[(a2$95$m * a2$95$m + N[(a1 * a1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      a2_m = \left|a2\right|
      \\
      [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\
      \\
      \frac{\cos th \cdot \mathsf{fma}\left(a2\_m, a2\_m, a1 \cdot a1\right)}{\sqrt{2}}
      \end{array}
      
      Derivation
      1. Initial program 99.6%

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

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

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

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

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

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

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

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

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

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

      Alternative 4: 99.6% accurate, 1.9× speedup?

      \[\begin{array}{l} a2_m = \left|a2\right| \\ [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\ \\ \frac{\mathsf{fma}\left(a1, a1, a2\_m \cdot a2\_m\right)}{\sqrt{2}} \cdot \cos th \end{array} \]
      a2_m = (fabs.f64 a2)
      NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
      (FPCore (a1 a2_m th)
       :precision binary64
       (* (/ (fma a1 a1 (* a2_m a2_m)) (sqrt 2.0)) (cos th)))
      a2_m = fabs(a2);
      assert(a1 < a2_m && a2_m < th);
      double code(double a1, double a2_m, double th) {
      	return (fma(a1, a1, (a2_m * a2_m)) / sqrt(2.0)) * cos(th);
      }
      
      a2_m = abs(a2)
      a1, a2_m, th = sort([a1, a2_m, th])
      function code(a1, a2_m, th)
      	return Float64(Float64(fma(a1, a1, Float64(a2_m * a2_m)) / sqrt(2.0)) * cos(th))
      end
      
      a2_m = N[Abs[a2], $MachinePrecision]
      NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
      code[a1_, a2$95$m_, th_] := N[(N[(N[(a1 * a1 + N[(a2$95$m * a2$95$m), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      a2_m = \left|a2\right|
      \\
      [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\
      \\
      \frac{\mathsf{fma}\left(a1, a1, a2\_m \cdot a2\_m\right)}{\sqrt{2}} \cdot \cos th
      \end{array}
      
      Derivation
      1. Initial program 99.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}} \cdot \cos th} \]
        14. lower-*.f6499.7

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

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

      Alternative 5: 99.6% accurate, 1.9× speedup?

      \[\begin{array}{l} a2_m = \left|a2\right| \\ [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\ \\ \left(\left(\mathsf{fma}\left(a2\_m, a2\_m, a1 \cdot a1\right) \cdot 0.5\right) \cdot \sqrt{2}\right) \cdot \cos th \end{array} \]
      a2_m = (fabs.f64 a2)
      NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
      (FPCore (a1 a2_m th)
       :precision binary64
       (* (* (* (fma a2_m a2_m (* a1 a1)) 0.5) (sqrt 2.0)) (cos th)))
      a2_m = fabs(a2);
      assert(a1 < a2_m && a2_m < th);
      double code(double a1, double a2_m, double th) {
      	return ((fma(a2_m, a2_m, (a1 * a1)) * 0.5) * sqrt(2.0)) * cos(th);
      }
      
      a2_m = abs(a2)
      a1, a2_m, th = sort([a1, a2_m, th])
      function code(a1, a2_m, th)
      	return Float64(Float64(Float64(fma(a2_m, a2_m, Float64(a1 * a1)) * 0.5) * sqrt(2.0)) * cos(th))
      end
      
      a2_m = N[Abs[a2], $MachinePrecision]
      NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
      code[a1_, a2$95$m_, th_] := N[(N[(N[(N[(a2$95$m * a2$95$m + N[(a1 * a1), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision] * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      a2_m = \left|a2\right|
      \\
      [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\
      \\
      \left(\left(\mathsf{fma}\left(a2\_m, a2\_m, a1 \cdot a1\right) \cdot 0.5\right) \cdot \sqrt{2}\right) \cdot \cos th
      \end{array}
      
      Derivation
      1. Initial program 99.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}} \cdot \cos th} \]
        14. lower-*.f6499.7

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \color{blue}{\left(\frac{1}{2} \cdot \left({a1}^{2} \cdot \sqrt{2}\right) + \frac{1}{2} \cdot \left({a2}^{2} \cdot \sqrt{2}\right)\right)} \cdot \cos th \]
      10. Step-by-step derivation
        1. Applied rewrites99.6%

          \[\leadsto \color{blue}{\left(\left(\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot 0.5\right) \cdot \sqrt{2}\right)} \cdot \cos th \]
        2. Final simplification99.6%

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

        Alternative 6: 78.7% accurate, 2.0× speedup?

        \[\begin{array}{l} a2_m = \left|a2\right| \\ [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\ \\ \frac{\cos th \cdot \left(a2\_m \cdot a2\_m\right)}{\sqrt{2}} \end{array} \]
        a2_m = (fabs.f64 a2)
        NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
        (FPCore (a1 a2_m th)
         :precision binary64
         (/ (* (cos th) (* a2_m a2_m)) (sqrt 2.0)))
        a2_m = fabs(a2);
        assert(a1 < a2_m && a2_m < th);
        double code(double a1, double a2_m, double th) {
        	return (cos(th) * (a2_m * a2_m)) / sqrt(2.0);
        }
        
        a2_m =     private
        NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
        module fmin_fmax_functions
            implicit none
            private
            public fmax
            public fmin
        
            interface fmax
                module procedure fmax88
                module procedure fmax44
                module procedure fmax84
                module procedure fmax48
            end interface
            interface fmin
                module procedure fmin88
                module procedure fmin44
                module procedure fmin84
                module procedure fmin48
            end interface
        contains
            real(8) function fmax88(x, y) result (res)
                real(8), intent (in) :: x
                real(8), intent (in) :: y
                res = merge(y, merge(x, max(x, y), y /= y), x /= x)
            end function
            real(4) function fmax44(x, y) result (res)
                real(4), intent (in) :: x
                real(4), intent (in) :: y
                res = merge(y, merge(x, max(x, y), y /= y), x /= x)
            end function
            real(8) function fmax84(x, y) result(res)
                real(8), intent (in) :: x
                real(4), intent (in) :: y
                res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
            end function
            real(8) function fmax48(x, y) result(res)
                real(4), intent (in) :: x
                real(8), intent (in) :: y
                res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
            end function
            real(8) function fmin88(x, y) result (res)
                real(8), intent (in) :: x
                real(8), intent (in) :: y
                res = merge(y, merge(x, min(x, y), y /= y), x /= x)
            end function
            real(4) function fmin44(x, y) result (res)
                real(4), intent (in) :: x
                real(4), intent (in) :: y
                res = merge(y, merge(x, min(x, y), y /= y), x /= x)
            end function
            real(8) function fmin84(x, y) result(res)
                real(8), intent (in) :: x
                real(4), intent (in) :: y
                res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
            end function
            real(8) function fmin48(x, y) result(res)
                real(4), intent (in) :: x
                real(8), intent (in) :: y
                res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
            end function
        end module
        
        real(8) function code(a1, a2_m, th)
        use fmin_fmax_functions
            real(8), intent (in) :: a1
            real(8), intent (in) :: a2_m
            real(8), intent (in) :: th
            code = (cos(th) * (a2_m * a2_m)) / sqrt(2.0d0)
        end function
        
        a2_m = Math.abs(a2);
        assert a1 < a2_m && a2_m < th;
        public static double code(double a1, double a2_m, double th) {
        	return (Math.cos(th) * (a2_m * a2_m)) / Math.sqrt(2.0);
        }
        
        a2_m = math.fabs(a2)
        [a1, a2_m, th] = sort([a1, a2_m, th])
        def code(a1, a2_m, th):
        	return (math.cos(th) * (a2_m * a2_m)) / math.sqrt(2.0)
        
        a2_m = abs(a2)
        a1, a2_m, th = sort([a1, a2_m, th])
        function code(a1, a2_m, th)
        	return Float64(Float64(cos(th) * Float64(a2_m * a2_m)) / sqrt(2.0))
        end
        
        a2_m = abs(a2);
        a1, a2_m, th = num2cell(sort([a1, a2_m, th])){:}
        function tmp = code(a1, a2_m, th)
        	tmp = (cos(th) * (a2_m * a2_m)) / sqrt(2.0);
        end
        
        a2_m = N[Abs[a2], $MachinePrecision]
        NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
        code[a1_, a2$95$m_, th_] := N[(N[(N[Cos[th], $MachinePrecision] * N[(a2$95$m * a2$95$m), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
        
        \begin{array}{l}
        a2_m = \left|a2\right|
        \\
        [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\
        \\
        \frac{\cos th \cdot \left(a2\_m \cdot a2\_m\right)}{\sqrt{2}}
        \end{array}
        
        Derivation
        1. Initial program 99.6%

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \frac{\cos th \cdot \color{blue}{{a2}^{2}}}{\sqrt{2}} \]
        6. Step-by-step derivation
          1. Applied rewrites58.6%

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

          Alternative 7: 78.7% accurate, 2.0× speedup?

          \[\begin{array}{l} a2_m = \left|a2\right| \\ [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\ \\ \frac{a2\_m \cdot a2\_m}{\sqrt{2}} \cdot \cos th \end{array} \]
          a2_m = (fabs.f64 a2)
          NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
          (FPCore (a1 a2_m th)
           :precision binary64
           (* (/ (* a2_m a2_m) (sqrt 2.0)) (cos th)))
          a2_m = fabs(a2);
          assert(a1 < a2_m && a2_m < th);
          double code(double a1, double a2_m, double th) {
          	return ((a2_m * a2_m) / sqrt(2.0)) * cos(th);
          }
          
          a2_m =     private
          NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
          module fmin_fmax_functions
              implicit none
              private
              public fmax
              public fmin
          
              interface fmax
                  module procedure fmax88
                  module procedure fmax44
                  module procedure fmax84
                  module procedure fmax48
              end interface
              interface fmin
                  module procedure fmin88
                  module procedure fmin44
                  module procedure fmin84
                  module procedure fmin48
              end interface
          contains
              real(8) function fmax88(x, y) result (res)
                  real(8), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
              end function
              real(4) function fmax44(x, y) result (res)
                  real(4), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
              end function
              real(8) function fmax84(x, y) result(res)
                  real(8), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
              end function
              real(8) function fmax48(x, y) result(res)
                  real(4), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
              end function
              real(8) function fmin88(x, y) result (res)
                  real(8), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
              end function
              real(4) function fmin44(x, y) result (res)
                  real(4), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
              end function
              real(8) function fmin84(x, y) result(res)
                  real(8), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
              end function
              real(8) function fmin48(x, y) result(res)
                  real(4), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
              end function
          end module
          
          real(8) function code(a1, a2_m, th)
          use fmin_fmax_functions
              real(8), intent (in) :: a1
              real(8), intent (in) :: a2_m
              real(8), intent (in) :: th
              code = ((a2_m * a2_m) / sqrt(2.0d0)) * cos(th)
          end function
          
          a2_m = Math.abs(a2);
          assert a1 < a2_m && a2_m < th;
          public static double code(double a1, double a2_m, double th) {
          	return ((a2_m * a2_m) / Math.sqrt(2.0)) * Math.cos(th);
          }
          
          a2_m = math.fabs(a2)
          [a1, a2_m, th] = sort([a1, a2_m, th])
          def code(a1, a2_m, th):
          	return ((a2_m * a2_m) / math.sqrt(2.0)) * math.cos(th)
          
          a2_m = abs(a2)
          a1, a2_m, th = sort([a1, a2_m, th])
          function code(a1, a2_m, th)
          	return Float64(Float64(Float64(a2_m * a2_m) / sqrt(2.0)) * cos(th))
          end
          
          a2_m = abs(a2);
          a1, a2_m, th = num2cell(sort([a1, a2_m, th])){:}
          function tmp = code(a1, a2_m, th)
          	tmp = ((a2_m * a2_m) / sqrt(2.0)) * cos(th);
          end
          
          a2_m = N[Abs[a2], $MachinePrecision]
          NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
          code[a1_, a2$95$m_, th_] := N[(N[(N[(a2$95$m * a2$95$m), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision]
          
          \begin{array}{l}
          a2_m = \left|a2\right|
          \\
          [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\
          \\
          \frac{a2\_m \cdot a2\_m}{\sqrt{2}} \cdot \cos th
          \end{array}
          
          Derivation
          1. Initial program 99.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}} \cdot \cos th} \]
            14. lower-*.f6499.7

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

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

            \[\leadsto \frac{\color{blue}{{a2}^{2}}}{\sqrt{2}} \cdot \cos th \]
          8. Step-by-step derivation
            1. Applied rewrites58.6%

              \[\leadsto \frac{\color{blue}{a2 \cdot a2}}{\sqrt{2}} \cdot \cos th \]
            2. Final simplification58.6%

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

            Alternative 8: 78.7% accurate, 2.0× speedup?

            \[\begin{array}{l} a2_m = \left|a2\right| \\ [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\ \\ \left(\left(a2\_m \cdot a2\_m\right) \cdot 0.5\right) \cdot \left(\sqrt{2} \cdot \cos th\right) \end{array} \]
            a2_m = (fabs.f64 a2)
            NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
            (FPCore (a1 a2_m th)
             :precision binary64
             (* (* (* a2_m a2_m) 0.5) (* (sqrt 2.0) (cos th))))
            a2_m = fabs(a2);
            assert(a1 < a2_m && a2_m < th);
            double code(double a1, double a2_m, double th) {
            	return ((a2_m * a2_m) * 0.5) * (sqrt(2.0) * cos(th));
            }
            
            a2_m =     private
            NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
            module fmin_fmax_functions
                implicit none
                private
                public fmax
                public fmin
            
                interface fmax
                    module procedure fmax88
                    module procedure fmax44
                    module procedure fmax84
                    module procedure fmax48
                end interface
                interface fmin
                    module procedure fmin88
                    module procedure fmin44
                    module procedure fmin84
                    module procedure fmin48
                end interface
            contains
                real(8) function fmax88(x, y) result (res)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                end function
                real(4) function fmax44(x, y) result (res)
                    real(4), intent (in) :: x
                    real(4), intent (in) :: y
                    res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                end function
                real(8) function fmax84(x, y) result(res)
                    real(8), intent (in) :: x
                    real(4), intent (in) :: y
                    res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                end function
                real(8) function fmax48(x, y) result(res)
                    real(4), intent (in) :: x
                    real(8), intent (in) :: y
                    res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                end function
                real(8) function fmin88(x, y) result (res)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                end function
                real(4) function fmin44(x, y) result (res)
                    real(4), intent (in) :: x
                    real(4), intent (in) :: y
                    res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                end function
                real(8) function fmin84(x, y) result(res)
                    real(8), intent (in) :: x
                    real(4), intent (in) :: y
                    res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                end function
                real(8) function fmin48(x, y) result(res)
                    real(4), intent (in) :: x
                    real(8), intent (in) :: y
                    res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                end function
            end module
            
            real(8) function code(a1, a2_m, th)
            use fmin_fmax_functions
                real(8), intent (in) :: a1
                real(8), intent (in) :: a2_m
                real(8), intent (in) :: th
                code = ((a2_m * a2_m) * 0.5d0) * (sqrt(2.0d0) * cos(th))
            end function
            
            a2_m = Math.abs(a2);
            assert a1 < a2_m && a2_m < th;
            public static double code(double a1, double a2_m, double th) {
            	return ((a2_m * a2_m) * 0.5) * (Math.sqrt(2.0) * Math.cos(th));
            }
            
            a2_m = math.fabs(a2)
            [a1, a2_m, th] = sort([a1, a2_m, th])
            def code(a1, a2_m, th):
            	return ((a2_m * a2_m) * 0.5) * (math.sqrt(2.0) * math.cos(th))
            
            a2_m = abs(a2)
            a1, a2_m, th = sort([a1, a2_m, th])
            function code(a1, a2_m, th)
            	return Float64(Float64(Float64(a2_m * a2_m) * 0.5) * Float64(sqrt(2.0) * cos(th)))
            end
            
            a2_m = abs(a2);
            a1, a2_m, th = num2cell(sort([a1, a2_m, th])){:}
            function tmp = code(a1, a2_m, th)
            	tmp = ((a2_m * a2_m) * 0.5) * (sqrt(2.0) * cos(th));
            end
            
            a2_m = N[Abs[a2], $MachinePrecision]
            NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
            code[a1_, a2$95$m_, th_] := N[(N[(N[(a2$95$m * a2$95$m), $MachinePrecision] * 0.5), $MachinePrecision] * N[(N[Sqrt[2.0], $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
            
            \begin{array}{l}
            a2_m = \left|a2\right|
            \\
            [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\
            \\
            \left(\left(a2\_m \cdot a2\_m\right) \cdot 0.5\right) \cdot \left(\sqrt{2} \cdot \cos th\right)
            \end{array}
            
            Derivation
            1. Initial program 99.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}} \cdot \cos th} \]
              14. lower-*.f6499.7

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \color{blue}{\frac{1}{2} \cdot \left({a2}^{2} \cdot \left(\cos th \cdot \sqrt{2}\right)\right)} \]
            10. Step-by-step derivation
              1. Applied rewrites58.6%

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

              Alternative 9: 65.8% accurate, 8.1× speedup?

              \[\begin{array}{l} a2_m = \left|a2\right| \\ [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\ \\ \frac{\mathsf{fma}\left(a2\_m, a2\_m, a1 \cdot a1\right)}{\sqrt{2}} \end{array} \]
              a2_m = (fabs.f64 a2)
              NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
              (FPCore (a1 a2_m th)
               :precision binary64
               (/ (fma a2_m a2_m (* a1 a1)) (sqrt 2.0)))
              a2_m = fabs(a2);
              assert(a1 < a2_m && a2_m < th);
              double code(double a1, double a2_m, double th) {
              	return fma(a2_m, a2_m, (a1 * a1)) / sqrt(2.0);
              }
              
              a2_m = abs(a2)
              a1, a2_m, th = sort([a1, a2_m, th])
              function code(a1, a2_m, th)
              	return Float64(fma(a2_m, a2_m, Float64(a1 * a1)) / sqrt(2.0))
              end
              
              a2_m = N[Abs[a2], $MachinePrecision]
              NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
              code[a1_, a2$95$m_, th_] := N[(N[(a2$95$m * a2$95$m + N[(a1 * a1), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
              
              \begin{array}{l}
              a2_m = \left|a2\right|
              \\
              [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\
              \\
              \frac{\mathsf{fma}\left(a2\_m, a2\_m, a1 \cdot a1\right)}{\sqrt{2}}
              \end{array}
              
              Derivation
              1. Initial program 99.6%

                \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
              2. Add Preprocessing
              3. 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. Applied rewrites66.2%

                  \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}}} \]
                2. Final simplification66.2%

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

                Alternative 10: 65.8% accurate, 8.3× speedup?

                \[\begin{array}{l} a2_m = \left|a2\right| \\ [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\ \\ \left(\mathsf{fma}\left(a2\_m, a2\_m, a1 \cdot a1\right) \cdot 0.5\right) \cdot \sqrt{2} \end{array} \]
                a2_m = (fabs.f64 a2)
                NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
                (FPCore (a1 a2_m th)
                 :precision binary64
                 (* (* (fma a2_m a2_m (* a1 a1)) 0.5) (sqrt 2.0)))
                a2_m = fabs(a2);
                assert(a1 < a2_m && a2_m < th);
                double code(double a1, double a2_m, double th) {
                	return (fma(a2_m, a2_m, (a1 * a1)) * 0.5) * sqrt(2.0);
                }
                
                a2_m = abs(a2)
                a1, a2_m, th = sort([a1, a2_m, th])
                function code(a1, a2_m, th)
                	return Float64(Float64(fma(a2_m, a2_m, Float64(a1 * a1)) * 0.5) * sqrt(2.0))
                end
                
                a2_m = N[Abs[a2], $MachinePrecision]
                NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
                code[a1_, a2$95$m_, th_] := N[(N[(N[(a2$95$m * a2$95$m + N[(a1 * a1), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision] * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
                
                \begin{array}{l}
                a2_m = \left|a2\right|
                \\
                [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\
                \\
                \left(\mathsf{fma}\left(a2\_m, a2\_m, a1 \cdot a1\right) \cdot 0.5\right) \cdot \sqrt{2}
                \end{array}
                
                Derivation
                1. Initial program 99.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}} \cdot \cos th} \]
                  14. lower-*.f6499.7

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                  \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(\sqrt{2} \cdot \left({a1}^{2} + {a2}^{2}\right)\right)} \]
                10. Step-by-step derivation
                  1. Applied rewrites66.1%

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

                  Alternative 11: 52.7% accurate, 9.9× speedup?

                  \[\begin{array}{l} a2_m = \left|a2\right| \\ [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\ \\ \frac{a2\_m \cdot a2\_m}{\sqrt{2}} \end{array} \]
                  a2_m = (fabs.f64 a2)
                  NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
                  (FPCore (a1 a2_m th) :precision binary64 (/ (* a2_m a2_m) (sqrt 2.0)))
                  a2_m = fabs(a2);
                  assert(a1 < a2_m && a2_m < th);
                  double code(double a1, double a2_m, double th) {
                  	return (a2_m * a2_m) / sqrt(2.0);
                  }
                  
                  a2_m =     private
                  NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
                  module fmin_fmax_functions
                      implicit none
                      private
                      public fmax
                      public fmin
                  
                      interface fmax
                          module procedure fmax88
                          module procedure fmax44
                          module procedure fmax84
                          module procedure fmax48
                      end interface
                      interface fmin
                          module procedure fmin88
                          module procedure fmin44
                          module procedure fmin84
                          module procedure fmin48
                      end interface
                  contains
                      real(8) function fmax88(x, y) result (res)
                          real(8), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                      end function
                      real(4) function fmax44(x, y) result (res)
                          real(4), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                      end function
                      real(8) function fmax84(x, y) result(res)
                          real(8), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                      end function
                      real(8) function fmax48(x, y) result(res)
                          real(4), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                      end function
                      real(8) function fmin88(x, y) result (res)
                          real(8), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                      end function
                      real(4) function fmin44(x, y) result (res)
                          real(4), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                      end function
                      real(8) function fmin84(x, y) result(res)
                          real(8), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                      end function
                      real(8) function fmin48(x, y) result(res)
                          real(4), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                      end function
                  end module
                  
                  real(8) function code(a1, a2_m, th)
                  use fmin_fmax_functions
                      real(8), intent (in) :: a1
                      real(8), intent (in) :: a2_m
                      real(8), intent (in) :: th
                      code = (a2_m * a2_m) / sqrt(2.0d0)
                  end function
                  
                  a2_m = Math.abs(a2);
                  assert a1 < a2_m && a2_m < th;
                  public static double code(double a1, double a2_m, double th) {
                  	return (a2_m * a2_m) / Math.sqrt(2.0);
                  }
                  
                  a2_m = math.fabs(a2)
                  [a1, a2_m, th] = sort([a1, a2_m, th])
                  def code(a1, a2_m, th):
                  	return (a2_m * a2_m) / math.sqrt(2.0)
                  
                  a2_m = abs(a2)
                  a1, a2_m, th = sort([a1, a2_m, th])
                  function code(a1, a2_m, th)
                  	return Float64(Float64(a2_m * a2_m) / sqrt(2.0))
                  end
                  
                  a2_m = abs(a2);
                  a1, a2_m, th = num2cell(sort([a1, a2_m, th])){:}
                  function tmp = code(a1, a2_m, th)
                  	tmp = (a2_m * a2_m) / sqrt(2.0);
                  end
                  
                  a2_m = N[Abs[a2], $MachinePrecision]
                  NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
                  code[a1_, a2$95$m_, th_] := N[(N[(a2$95$m * a2$95$m), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
                  
                  \begin{array}{l}
                  a2_m = \left|a2\right|
                  \\
                  [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\
                  \\
                  \frac{a2\_m \cdot a2\_m}{\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. 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. Applied rewrites66.2%

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

                      \[\leadsto \frac{{a2}^{2}}{\sqrt{\color{blue}{2}}} \]
                    3. Step-by-step derivation
                      1. Applied rewrites39.5%

                        \[\leadsto \frac{a2 \cdot a2}{\sqrt{\color{blue}{2}}} \]
                      2. Final simplification39.5%

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

                      Alternative 12: 52.7% accurate, 9.9× speedup?

                      \[\begin{array}{l} a2_m = \left|a2\right| \\ [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\ \\ a2\_m \cdot \frac{a2\_m}{\sqrt{2}} \end{array} \]
                      a2_m = (fabs.f64 a2)
                      NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
                      (FPCore (a1 a2_m th) :precision binary64 (* a2_m (/ a2_m (sqrt 2.0))))
                      a2_m = fabs(a2);
                      assert(a1 < a2_m && a2_m < th);
                      double code(double a1, double a2_m, double th) {
                      	return a2_m * (a2_m / sqrt(2.0));
                      }
                      
                      a2_m =     private
                      NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
                      module fmin_fmax_functions
                          implicit none
                          private
                          public fmax
                          public fmin
                      
                          interface fmax
                              module procedure fmax88
                              module procedure fmax44
                              module procedure fmax84
                              module procedure fmax48
                          end interface
                          interface fmin
                              module procedure fmin88
                              module procedure fmin44
                              module procedure fmin84
                              module procedure fmin48
                          end interface
                      contains
                          real(8) function fmax88(x, y) result (res)
                              real(8), intent (in) :: x
                              real(8), intent (in) :: y
                              res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                          end function
                          real(4) function fmax44(x, y) result (res)
                              real(4), intent (in) :: x
                              real(4), intent (in) :: y
                              res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                          end function
                          real(8) function fmax84(x, y) result(res)
                              real(8), intent (in) :: x
                              real(4), intent (in) :: y
                              res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                          end function
                          real(8) function fmax48(x, y) result(res)
                              real(4), intent (in) :: x
                              real(8), intent (in) :: y
                              res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                          end function
                          real(8) function fmin88(x, y) result (res)
                              real(8), intent (in) :: x
                              real(8), intent (in) :: y
                              res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                          end function
                          real(4) function fmin44(x, y) result (res)
                              real(4), intent (in) :: x
                              real(4), intent (in) :: y
                              res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                          end function
                          real(8) function fmin84(x, y) result(res)
                              real(8), intent (in) :: x
                              real(4), intent (in) :: y
                              res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                          end function
                          real(8) function fmin48(x, y) result(res)
                              real(4), intent (in) :: x
                              real(8), intent (in) :: y
                              res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                          end function
                      end module
                      
                      real(8) function code(a1, a2_m, th)
                      use fmin_fmax_functions
                          real(8), intent (in) :: a1
                          real(8), intent (in) :: a2_m
                          real(8), intent (in) :: th
                          code = a2_m * (a2_m / sqrt(2.0d0))
                      end function
                      
                      a2_m = Math.abs(a2);
                      assert a1 < a2_m && a2_m < th;
                      public static double code(double a1, double a2_m, double th) {
                      	return a2_m * (a2_m / Math.sqrt(2.0));
                      }
                      
                      a2_m = math.fabs(a2)
                      [a1, a2_m, th] = sort([a1, a2_m, th])
                      def code(a1, a2_m, th):
                      	return a2_m * (a2_m / math.sqrt(2.0))
                      
                      a2_m = abs(a2)
                      a1, a2_m, th = sort([a1, a2_m, th])
                      function code(a1, a2_m, th)
                      	return Float64(a2_m * Float64(a2_m / sqrt(2.0)))
                      end
                      
                      a2_m = abs(a2);
                      a1, a2_m, th = num2cell(sort([a1, a2_m, th])){:}
                      function tmp = code(a1, a2_m, th)
                      	tmp = a2_m * (a2_m / sqrt(2.0));
                      end
                      
                      a2_m = N[Abs[a2], $MachinePrecision]
                      NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
                      code[a1_, a2$95$m_, th_] := N[(a2$95$m * N[(a2$95$m / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
                      
                      \begin{array}{l}
                      a2_m = \left|a2\right|
                      \\
                      [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\
                      \\
                      a2\_m \cdot \frac{a2\_m}{\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. 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. Applied rewrites66.2%

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

                          \[\leadsto \frac{{a2}^{2}}{\color{blue}{\sqrt{2}}} \]
                        3. Step-by-step derivation
                          1. Applied rewrites39.6%

                            \[\leadsto a2 \cdot \color{blue}{\frac{a2}{\sqrt{2}}} \]
                          2. Final simplification39.6%

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

                          Alternative 13: 26.2% accurate, 9.9× speedup?

                          \[\begin{array}{l} a2_m = \left|a2\right| \\ [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\ \\ a1 \cdot \frac{a1}{\sqrt{2}} \end{array} \]
                          a2_m = (fabs.f64 a2)
                          NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
                          (FPCore (a1 a2_m th) :precision binary64 (* a1 (/ a1 (sqrt 2.0))))
                          a2_m = fabs(a2);
                          assert(a1 < a2_m && a2_m < th);
                          double code(double a1, double a2_m, double th) {
                          	return a1 * (a1 / sqrt(2.0));
                          }
                          
                          a2_m =     private
                          NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
                          module fmin_fmax_functions
                              implicit none
                              private
                              public fmax
                              public fmin
                          
                              interface fmax
                                  module procedure fmax88
                                  module procedure fmax44
                                  module procedure fmax84
                                  module procedure fmax48
                              end interface
                              interface fmin
                                  module procedure fmin88
                                  module procedure fmin44
                                  module procedure fmin84
                                  module procedure fmin48
                              end interface
                          contains
                              real(8) function fmax88(x, y) result (res)
                                  real(8), intent (in) :: x
                                  real(8), intent (in) :: y
                                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                              end function
                              real(4) function fmax44(x, y) result (res)
                                  real(4), intent (in) :: x
                                  real(4), intent (in) :: y
                                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                              end function
                              real(8) function fmax84(x, y) result(res)
                                  real(8), intent (in) :: x
                                  real(4), intent (in) :: y
                                  res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                              end function
                              real(8) function fmax48(x, y) result(res)
                                  real(4), intent (in) :: x
                                  real(8), intent (in) :: y
                                  res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                              end function
                              real(8) function fmin88(x, y) result (res)
                                  real(8), intent (in) :: x
                                  real(8), intent (in) :: y
                                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                              end function
                              real(4) function fmin44(x, y) result (res)
                                  real(4), intent (in) :: x
                                  real(4), intent (in) :: y
                                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                              end function
                              real(8) function fmin84(x, y) result(res)
                                  real(8), intent (in) :: x
                                  real(4), intent (in) :: y
                                  res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                              end function
                              real(8) function fmin48(x, y) result(res)
                                  real(4), intent (in) :: x
                                  real(8), intent (in) :: y
                                  res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                              end function
                          end module
                          
                          real(8) function code(a1, a2_m, th)
                          use fmin_fmax_functions
                              real(8), intent (in) :: a1
                              real(8), intent (in) :: a2_m
                              real(8), intent (in) :: th
                              code = a1 * (a1 / sqrt(2.0d0))
                          end function
                          
                          a2_m = Math.abs(a2);
                          assert a1 < a2_m && a2_m < th;
                          public static double code(double a1, double a2_m, double th) {
                          	return a1 * (a1 / Math.sqrt(2.0));
                          }
                          
                          a2_m = math.fabs(a2)
                          [a1, a2_m, th] = sort([a1, a2_m, th])
                          def code(a1, a2_m, th):
                          	return a1 * (a1 / math.sqrt(2.0))
                          
                          a2_m = abs(a2)
                          a1, a2_m, th = sort([a1, a2_m, th])
                          function code(a1, a2_m, th)
                          	return Float64(a1 * Float64(a1 / sqrt(2.0)))
                          end
                          
                          a2_m = abs(a2);
                          a1, a2_m, th = num2cell(sort([a1, a2_m, th])){:}
                          function tmp = code(a1, a2_m, th)
                          	tmp = a1 * (a1 / sqrt(2.0));
                          end
                          
                          a2_m = N[Abs[a2], $MachinePrecision]
                          NOTE: a1, a2_m, and th should be sorted in increasing order before calling this function.
                          code[a1_, a2$95$m_, th_] := N[(a1 * N[(a1 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
                          
                          \begin{array}{l}
                          a2_m = \left|a2\right|
                          \\
                          [a1, a2_m, th] = \mathsf{sort}([a1, a2_m, th])\\
                          \\
                          a1 \cdot \frac{a1}{\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. 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. Applied rewrites66.2%

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

                              \[\leadsto \frac{{a1}^{2}}{\color{blue}{\sqrt{2}}} \]
                            3. Step-by-step derivation
                              1. Applied rewrites38.7%

                                \[\leadsto a1 \cdot \color{blue}{\frac{a1}{\sqrt{2}}} \]
                              2. Final simplification38.7%

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

                              Reproduce

                              ?
                              herbie shell --seed 2025019 
                              (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))))