2cos (problem 3.3.5)

Percentage Accurate: 37.7% → 99.3%
Time: 18.6s
Alternatives: 15
Speedup: 2.0×

Specification

?
\[\begin{array}{l} \\ \cos \left(x + \varepsilon\right) - \cos x \end{array} \]
(FPCore (x eps) :precision binary64 (- (cos (+ x eps)) (cos x)))
double code(double x, double eps) {
	return cos((x + eps)) - cos(x);
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = cos((x + eps)) - cos(x)
end function
public static double code(double x, double eps) {
	return Math.cos((x + eps)) - Math.cos(x);
}
def code(x, eps):
	return math.cos((x + eps)) - math.cos(x)
function code(x, eps)
	return Float64(cos(Float64(x + eps)) - cos(x))
end
function tmp = code(x, eps)
	tmp = cos((x + eps)) - cos(x);
end
code[x_, eps_] := N[(N[Cos[N[(x + eps), $MachinePrecision]], $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\cos \left(x + \varepsilon\right) - \cos x
\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 15 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: 37.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \cos \left(x + \varepsilon\right) - \cos x \end{array} \]
(FPCore (x eps) :precision binary64 (- (cos (+ x eps)) (cos x)))
double code(double x, double eps) {
	return cos((x + eps)) - cos(x);
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = cos((x + eps)) - cos(x)
end function
public static double code(double x, double eps) {
	return Math.cos((x + eps)) - Math.cos(x);
}
def code(x, eps):
	return math.cos((x + eps)) - math.cos(x)
function code(x, eps)
	return Float64(cos(Float64(x + eps)) - cos(x))
end
function tmp = code(x, eps)
	tmp = cos((x + eps)) - cos(x);
end
code[x_, eps_] := N[(N[Cos[N[(x + eps), $MachinePrecision]], $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\cos \left(x + \varepsilon\right) - \cos x
\end{array}

Alternative 1: 99.3% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sin \varepsilon \cdot \sin x\\ \mathbf{if}\;\varepsilon \leq -0.0055:\\ \;\;\;\;\left(\cos x \cdot \cos \varepsilon - \cos x\right) - t_0\\ \mathbf{elif}\;\varepsilon \leq 0.0045:\\ \;\;\;\;\cos x \cdot \left(-0.5 \cdot {\varepsilon}^{2} + 0.041666666666666664 \cdot {\varepsilon}^{4}\right) - t_0\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\cos x, \cos \varepsilon, \sin \varepsilon \cdot \left(-\sin x\right)\right) - \cos x\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (* (sin eps) (sin x))))
   (if (<= eps -0.0055)
     (- (- (* (cos x) (cos eps)) (cos x)) t_0)
     (if (<= eps 0.0045)
       (-
        (*
         (cos x)
         (+ (* -0.5 (pow eps 2.0)) (* 0.041666666666666664 (pow eps 4.0))))
        t_0)
       (- (fma (cos x) (cos eps) (* (sin eps) (- (sin x)))) (cos x))))))
double code(double x, double eps) {
	double t_0 = sin(eps) * sin(x);
	double tmp;
	if (eps <= -0.0055) {
		tmp = ((cos(x) * cos(eps)) - cos(x)) - t_0;
	} else if (eps <= 0.0045) {
		tmp = (cos(x) * ((-0.5 * pow(eps, 2.0)) + (0.041666666666666664 * pow(eps, 4.0)))) - t_0;
	} else {
		tmp = fma(cos(x), cos(eps), (sin(eps) * -sin(x))) - cos(x);
	}
	return tmp;
}
function code(x, eps)
	t_0 = Float64(sin(eps) * sin(x))
	tmp = 0.0
	if (eps <= -0.0055)
		tmp = Float64(Float64(Float64(cos(x) * cos(eps)) - cos(x)) - t_0);
	elseif (eps <= 0.0045)
		tmp = Float64(Float64(cos(x) * Float64(Float64(-0.5 * (eps ^ 2.0)) + Float64(0.041666666666666664 * (eps ^ 4.0)))) - t_0);
	else
		tmp = Float64(fma(cos(x), cos(eps), Float64(sin(eps) * Float64(-sin(x)))) - cos(x));
	end
	return tmp
end
code[x_, eps_] := Block[{t$95$0 = N[(N[Sin[eps], $MachinePrecision] * N[Sin[x], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[eps, -0.0055], N[(N[(N[(N[Cos[x], $MachinePrecision] * N[Cos[eps], $MachinePrecision]), $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision] - t$95$0), $MachinePrecision], If[LessEqual[eps, 0.0045], N[(N[(N[Cos[x], $MachinePrecision] * N[(N[(-0.5 * N[Power[eps, 2.0], $MachinePrecision]), $MachinePrecision] + N[(0.041666666666666664 * N[Power[eps, 4.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - t$95$0), $MachinePrecision], N[(N[(N[Cos[x], $MachinePrecision] * N[Cos[eps], $MachinePrecision] + N[(N[Sin[eps], $MachinePrecision] * (-N[Sin[x], $MachinePrecision])), $MachinePrecision]), $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sin \varepsilon \cdot \sin x\\
\mathbf{if}\;\varepsilon \leq -0.0055:\\
\;\;\;\;\left(\cos x \cdot \cos \varepsilon - \cos x\right) - t_0\\

\mathbf{elif}\;\varepsilon \leq 0.0045:\\
\;\;\;\;\cos x \cdot \left(-0.5 \cdot {\varepsilon}^{2} + 0.041666666666666664 \cdot {\varepsilon}^{4}\right) - t_0\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\cos x, \cos \varepsilon, \sin \varepsilon \cdot \left(-\sin x\right)\right) - \cos x\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if eps < -0.0054999999999999997

    1. Initial program 62.6%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. cos-sum98.7%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \]
      2. cancel-sign-sub-inv98.7%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
      3. fma-def98.7%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    4. Applied egg-rr98.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    5. Taylor expanded in x around inf 98.7%

      \[\leadsto \color{blue}{\left(-1 \cdot \left(\sin \varepsilon \cdot \sin x\right) + \cos \varepsilon \cdot \cos x\right) - \cos x} \]
    6. Step-by-step derivation
      1. neg-mul-198.7%

        \[\leadsto \left(\color{blue}{\left(-\sin \varepsilon \cdot \sin x\right)} + \cos \varepsilon \cdot \cos x\right) - \cos x \]
      2. +-commutative98.7%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + \left(-\sin \varepsilon \cdot \sin x\right)\right)} - \cos x \]
      3. sub-neg98.7%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x - \sin \varepsilon \cdot \sin x\right)} - \cos x \]
      4. *-commutative98.7%

        \[\leadsto \left(\color{blue}{\cos x \cdot \cos \varepsilon} - \sin \varepsilon \cdot \sin x\right) - \cos x \]
      5. associate--r+98.7%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \sin x + \cos x\right)} \]
      6. +-commutative98.7%

        \[\leadsto \cos x \cdot \cos \varepsilon - \color{blue}{\left(\cos x + \sin \varepsilon \cdot \sin x\right)} \]
      7. associate--r+98.8%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \cos x\right) - \sin \varepsilon \cdot \sin x} \]
      8. *-rgt-identity98.8%

        \[\leadsto \left(\cos x \cdot \cos \varepsilon - \color{blue}{\cos x \cdot 1}\right) - \sin \varepsilon \cdot \sin x \]
      9. distribute-lft-out--98.8%

        \[\leadsto \color{blue}{\cos x \cdot \left(\cos \varepsilon - 1\right)} - \sin \varepsilon \cdot \sin x \]
      10. sub-neg98.8%

        \[\leadsto \cos x \cdot \color{blue}{\left(\cos \varepsilon + \left(-1\right)\right)} - \sin \varepsilon \cdot \sin x \]
      11. metadata-eval98.8%

        \[\leadsto \cos x \cdot \left(\cos \varepsilon + \color{blue}{-1}\right) - \sin \varepsilon \cdot \sin x \]
      12. +-commutative98.8%

        \[\leadsto \cos x \cdot \color{blue}{\left(-1 + \cos \varepsilon\right)} - \sin \varepsilon \cdot \sin x \]
      13. *-commutative98.8%

        \[\leadsto \cos x \cdot \left(-1 + \cos \varepsilon\right) - \color{blue}{\sin x \cdot \sin \varepsilon} \]
    7. Simplified98.8%

      \[\leadsto \color{blue}{\cos x \cdot \left(-1 + \cos \varepsilon\right) - \sin x \cdot \sin \varepsilon} \]
    8. Step-by-step derivation
      1. +-commutative98.8%

        \[\leadsto \cos x \cdot \color{blue}{\left(\cos \varepsilon + -1\right)} - \sin x \cdot \sin \varepsilon \]
      2. distribute-rgt-in98.8%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + -1 \cdot \cos x\right)} - \sin x \cdot \sin \varepsilon \]
      3. neg-mul-198.8%

        \[\leadsto \left(\cos \varepsilon \cdot \cos x + \color{blue}{\left(-\cos x\right)}\right) - \sin x \cdot \sin \varepsilon \]
    9. Applied egg-rr98.8%

      \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + \left(-\cos x\right)\right)} - \sin x \cdot \sin \varepsilon \]
    10. Taylor expanded in eps around inf 98.8%

      \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x - \cos x\right)} - \sin x \cdot \sin \varepsilon \]

    if -0.0054999999999999997 < eps < 0.00449999999999999966

    1. Initial program 24.9%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. cos-sum26.1%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \]
      2. cancel-sign-sub-inv26.1%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
      3. fma-def26.1%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    4. Applied egg-rr26.1%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    5. Taylor expanded in x around inf 26.1%

      \[\leadsto \color{blue}{\left(-1 \cdot \left(\sin \varepsilon \cdot \sin x\right) + \cos \varepsilon \cdot \cos x\right) - \cos x} \]
    6. Step-by-step derivation
      1. neg-mul-126.1%

        \[\leadsto \left(\color{blue}{\left(-\sin \varepsilon \cdot \sin x\right)} + \cos \varepsilon \cdot \cos x\right) - \cos x \]
      2. +-commutative26.1%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + \left(-\sin \varepsilon \cdot \sin x\right)\right)} - \cos x \]
      3. sub-neg26.1%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x - \sin \varepsilon \cdot \sin x\right)} - \cos x \]
      4. *-commutative26.1%

        \[\leadsto \left(\color{blue}{\cos x \cdot \cos \varepsilon} - \sin \varepsilon \cdot \sin x\right) - \cos x \]
      5. associate--r+26.1%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \sin x + \cos x\right)} \]
      6. +-commutative26.1%

        \[\leadsto \cos x \cdot \cos \varepsilon - \color{blue}{\left(\cos x + \sin \varepsilon \cdot \sin x\right)} \]
      7. associate--r+83.4%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \cos x\right) - \sin \varepsilon \cdot \sin x} \]
      8. *-rgt-identity83.4%

        \[\leadsto \left(\cos x \cdot \cos \varepsilon - \color{blue}{\cos x \cdot 1}\right) - \sin \varepsilon \cdot \sin x \]
      9. distribute-lft-out--83.4%

        \[\leadsto \color{blue}{\cos x \cdot \left(\cos \varepsilon - 1\right)} - \sin \varepsilon \cdot \sin x \]
      10. sub-neg83.4%

        \[\leadsto \cos x \cdot \color{blue}{\left(\cos \varepsilon + \left(-1\right)\right)} - \sin \varepsilon \cdot \sin x \]
      11. metadata-eval83.4%

        \[\leadsto \cos x \cdot \left(\cos \varepsilon + \color{blue}{-1}\right) - \sin \varepsilon \cdot \sin x \]
      12. +-commutative83.4%

        \[\leadsto \cos x \cdot \color{blue}{\left(-1 + \cos \varepsilon\right)} - \sin \varepsilon \cdot \sin x \]
      13. *-commutative83.4%

        \[\leadsto \cos x \cdot \left(-1 + \cos \varepsilon\right) - \color{blue}{\sin x \cdot \sin \varepsilon} \]
    7. Simplified83.4%

      \[\leadsto \color{blue}{\cos x \cdot \left(-1 + \cos \varepsilon\right) - \sin x \cdot \sin \varepsilon} \]
    8. Taylor expanded in eps around 0 99.8%

      \[\leadsto \cos x \cdot \color{blue}{\left(-0.5 \cdot {\varepsilon}^{2} + 0.041666666666666664 \cdot {\varepsilon}^{4}\right)} - \sin x \cdot \sin \varepsilon \]

    if 0.00449999999999999966 < eps

    1. Initial program 49.8%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. cos-sum99.1%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \]
      2. cancel-sign-sub-inv99.1%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
      3. fma-def99.1%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    4. Applied egg-rr99.1%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.0055:\\ \;\;\;\;\left(\cos x \cdot \cos \varepsilon - \cos x\right) - \sin \varepsilon \cdot \sin x\\ \mathbf{elif}\;\varepsilon \leq 0.0045:\\ \;\;\;\;\cos x \cdot \left(-0.5 \cdot {\varepsilon}^{2} + 0.041666666666666664 \cdot {\varepsilon}^{4}\right) - \sin \varepsilon \cdot \sin x\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\cos x, \cos \varepsilon, \sin \varepsilon \cdot \left(-\sin x\right)\right) - \cos x\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 99.0% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \frac{{\sin \varepsilon}^{2} \cdot \cos x}{-1 - \cos \varepsilon} - \sin \varepsilon \cdot \sin x \end{array} \]
(FPCore (x eps)
 :precision binary64
 (-
  (/ (* (pow (sin eps) 2.0) (cos x)) (- -1.0 (cos eps)))
  (* (sin eps) (sin x))))
double code(double x, double eps) {
	return ((pow(sin(eps), 2.0) * cos(x)) / (-1.0 - cos(eps))) - (sin(eps) * sin(x));
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = (((sin(eps) ** 2.0d0) * cos(x)) / ((-1.0d0) - cos(eps))) - (sin(eps) * sin(x))
end function
public static double code(double x, double eps) {
	return ((Math.pow(Math.sin(eps), 2.0) * Math.cos(x)) / (-1.0 - Math.cos(eps))) - (Math.sin(eps) * Math.sin(x));
}
def code(x, eps):
	return ((math.pow(math.sin(eps), 2.0) * math.cos(x)) / (-1.0 - math.cos(eps))) - (math.sin(eps) * math.sin(x))
function code(x, eps)
	return Float64(Float64(Float64((sin(eps) ^ 2.0) * cos(x)) / Float64(-1.0 - cos(eps))) - Float64(sin(eps) * sin(x)))
end
function tmp = code(x, eps)
	tmp = (((sin(eps) ^ 2.0) * cos(x)) / (-1.0 - cos(eps))) - (sin(eps) * sin(x));
end
code[x_, eps_] := N[(N[(N[(N[Power[N[Sin[eps], $MachinePrecision], 2.0], $MachinePrecision] * N[Cos[x], $MachinePrecision]), $MachinePrecision] / N[(-1.0 - N[Cos[eps], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(N[Sin[eps], $MachinePrecision] * N[Sin[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{{\sin \varepsilon}^{2} \cdot \cos x}{-1 - \cos \varepsilon} - \sin \varepsilon \cdot \sin x
\end{array}
Derivation
  1. Initial program 40.1%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. cos-sum63.1%

      \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \]
    2. cancel-sign-sub-inv63.1%

      \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    3. fma-def63.1%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
  4. Applied egg-rr63.1%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
  5. Taylor expanded in x around inf 63.1%

    \[\leadsto \color{blue}{\left(-1 \cdot \left(\sin \varepsilon \cdot \sin x\right) + \cos \varepsilon \cdot \cos x\right) - \cos x} \]
  6. Step-by-step derivation
    1. neg-mul-163.1%

      \[\leadsto \left(\color{blue}{\left(-\sin \varepsilon \cdot \sin x\right)} + \cos \varepsilon \cdot \cos x\right) - \cos x \]
    2. +-commutative63.1%

      \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + \left(-\sin \varepsilon \cdot \sin x\right)\right)} - \cos x \]
    3. sub-neg63.1%

      \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x - \sin \varepsilon \cdot \sin x\right)} - \cos x \]
    4. *-commutative63.1%

      \[\leadsto \left(\color{blue}{\cos x \cdot \cos \varepsilon} - \sin \varepsilon \cdot \sin x\right) - \cos x \]
    5. associate--r+63.1%

      \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \sin x + \cos x\right)} \]
    6. +-commutative63.1%

      \[\leadsto \cos x \cdot \cos \varepsilon - \color{blue}{\left(\cos x + \sin \varepsilon \cdot \sin x\right)} \]
    7. associate--r+91.3%

      \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \cos x\right) - \sin \varepsilon \cdot \sin x} \]
    8. *-rgt-identity91.3%

      \[\leadsto \left(\cos x \cdot \cos \varepsilon - \color{blue}{\cos x \cdot 1}\right) - \sin \varepsilon \cdot \sin x \]
    9. distribute-lft-out--91.3%

      \[\leadsto \color{blue}{\cos x \cdot \left(\cos \varepsilon - 1\right)} - \sin \varepsilon \cdot \sin x \]
    10. sub-neg91.3%

      \[\leadsto \cos x \cdot \color{blue}{\left(\cos \varepsilon + \left(-1\right)\right)} - \sin \varepsilon \cdot \sin x \]
    11. metadata-eval91.3%

      \[\leadsto \cos x \cdot \left(\cos \varepsilon + \color{blue}{-1}\right) - \sin \varepsilon \cdot \sin x \]
    12. +-commutative91.3%

      \[\leadsto \cos x \cdot \color{blue}{\left(-1 + \cos \varepsilon\right)} - \sin \varepsilon \cdot \sin x \]
    13. *-commutative91.3%

      \[\leadsto \cos x \cdot \left(-1 + \cos \varepsilon\right) - \color{blue}{\sin x \cdot \sin \varepsilon} \]
  7. Simplified91.3%

    \[\leadsto \color{blue}{\cos x \cdot \left(-1 + \cos \varepsilon\right) - \sin x \cdot \sin \varepsilon} \]
  8. Step-by-step derivation
    1. *-commutative91.3%

      \[\leadsto \color{blue}{\left(-1 + \cos \varepsilon\right) \cdot \cos x} - \sin x \cdot \sin \varepsilon \]
    2. flip-+90.8%

      \[\leadsto \color{blue}{\frac{-1 \cdot -1 - \cos \varepsilon \cdot \cos \varepsilon}{-1 - \cos \varepsilon}} \cdot \cos x - \sin x \cdot \sin \varepsilon \]
    3. associate-*l/90.8%

      \[\leadsto \color{blue}{\frac{\left(-1 \cdot -1 - \cos \varepsilon \cdot \cos \varepsilon\right) \cdot \cos x}{-1 - \cos \varepsilon}} - \sin x \cdot \sin \varepsilon \]
    4. metadata-eval90.8%

      \[\leadsto \frac{\left(\color{blue}{1} - \cos \varepsilon \cdot \cos \varepsilon\right) \cdot \cos x}{-1 - \cos \varepsilon} - \sin x \cdot \sin \varepsilon \]
    5. 1-sub-cos98.8%

      \[\leadsto \frac{\color{blue}{\left(\sin \varepsilon \cdot \sin \varepsilon\right)} \cdot \cos x}{-1 - \cos \varepsilon} - \sin x \cdot \sin \varepsilon \]
    6. pow298.8%

      \[\leadsto \frac{\color{blue}{{\sin \varepsilon}^{2}} \cdot \cos x}{-1 - \cos \varepsilon} - \sin x \cdot \sin \varepsilon \]
  9. Applied egg-rr98.8%

    \[\leadsto \color{blue}{\frac{{\sin \varepsilon}^{2} \cdot \cos x}{-1 - \cos \varepsilon}} - \sin x \cdot \sin \varepsilon \]
  10. Final simplification98.8%

    \[\leadsto \frac{{\sin \varepsilon}^{2} \cdot \cos x}{-1 - \cos \varepsilon} - \sin \varepsilon \cdot \sin x \]
  11. Add Preprocessing

Alternative 3: 99.3% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos x \cdot \cos \varepsilon\\ t_1 := \sin \varepsilon \cdot \sin x\\ \mathbf{if}\;\varepsilon \leq -0.0055:\\ \;\;\;\;\left(t_0 - \cos x\right) - t_1\\ \mathbf{elif}\;\varepsilon \leq 0.0052:\\ \;\;\;\;\cos x \cdot \left(-0.5 \cdot {\varepsilon}^{2} + 0.041666666666666664 \cdot {\varepsilon}^{4}\right) - t_1\\ \mathbf{else}:\\ \;\;\;\;t_0 - \left(\cos x + t_1\right)\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (* (cos x) (cos eps))) (t_1 (* (sin eps) (sin x))))
   (if (<= eps -0.0055)
     (- (- t_0 (cos x)) t_1)
     (if (<= eps 0.0052)
       (-
        (*
         (cos x)
         (+ (* -0.5 (pow eps 2.0)) (* 0.041666666666666664 (pow eps 4.0))))
        t_1)
       (- t_0 (+ (cos x) t_1))))))
double code(double x, double eps) {
	double t_0 = cos(x) * cos(eps);
	double t_1 = sin(eps) * sin(x);
	double tmp;
	if (eps <= -0.0055) {
		tmp = (t_0 - cos(x)) - t_1;
	} else if (eps <= 0.0052) {
		tmp = (cos(x) * ((-0.5 * pow(eps, 2.0)) + (0.041666666666666664 * pow(eps, 4.0)))) - t_1;
	} else {
		tmp = t_0 - (cos(x) + t_1);
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = cos(x) * cos(eps)
    t_1 = sin(eps) * sin(x)
    if (eps <= (-0.0055d0)) then
        tmp = (t_0 - cos(x)) - t_1
    else if (eps <= 0.0052d0) then
        tmp = (cos(x) * (((-0.5d0) * (eps ** 2.0d0)) + (0.041666666666666664d0 * (eps ** 4.0d0)))) - t_1
    else
        tmp = t_0 - (cos(x) + t_1)
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double t_0 = Math.cos(x) * Math.cos(eps);
	double t_1 = Math.sin(eps) * Math.sin(x);
	double tmp;
	if (eps <= -0.0055) {
		tmp = (t_0 - Math.cos(x)) - t_1;
	} else if (eps <= 0.0052) {
		tmp = (Math.cos(x) * ((-0.5 * Math.pow(eps, 2.0)) + (0.041666666666666664 * Math.pow(eps, 4.0)))) - t_1;
	} else {
		tmp = t_0 - (Math.cos(x) + t_1);
	}
	return tmp;
}
def code(x, eps):
	t_0 = math.cos(x) * math.cos(eps)
	t_1 = math.sin(eps) * math.sin(x)
	tmp = 0
	if eps <= -0.0055:
		tmp = (t_0 - math.cos(x)) - t_1
	elif eps <= 0.0052:
		tmp = (math.cos(x) * ((-0.5 * math.pow(eps, 2.0)) + (0.041666666666666664 * math.pow(eps, 4.0)))) - t_1
	else:
		tmp = t_0 - (math.cos(x) + t_1)
	return tmp
function code(x, eps)
	t_0 = Float64(cos(x) * cos(eps))
	t_1 = Float64(sin(eps) * sin(x))
	tmp = 0.0
	if (eps <= -0.0055)
		tmp = Float64(Float64(t_0 - cos(x)) - t_1);
	elseif (eps <= 0.0052)
		tmp = Float64(Float64(cos(x) * Float64(Float64(-0.5 * (eps ^ 2.0)) + Float64(0.041666666666666664 * (eps ^ 4.0)))) - t_1);
	else
		tmp = Float64(t_0 - Float64(cos(x) + t_1));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	t_0 = cos(x) * cos(eps);
	t_1 = sin(eps) * sin(x);
	tmp = 0.0;
	if (eps <= -0.0055)
		tmp = (t_0 - cos(x)) - t_1;
	elseif (eps <= 0.0052)
		tmp = (cos(x) * ((-0.5 * (eps ^ 2.0)) + (0.041666666666666664 * (eps ^ 4.0)))) - t_1;
	else
		tmp = t_0 - (cos(x) + t_1);
	end
	tmp_2 = tmp;
end
code[x_, eps_] := Block[{t$95$0 = N[(N[Cos[x], $MachinePrecision] * N[Cos[eps], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[Sin[eps], $MachinePrecision] * N[Sin[x], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[eps, -0.0055], N[(N[(t$95$0 - N[Cos[x], $MachinePrecision]), $MachinePrecision] - t$95$1), $MachinePrecision], If[LessEqual[eps, 0.0052], N[(N[(N[Cos[x], $MachinePrecision] * N[(N[(-0.5 * N[Power[eps, 2.0], $MachinePrecision]), $MachinePrecision] + N[(0.041666666666666664 * N[Power[eps, 4.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - t$95$1), $MachinePrecision], N[(t$95$0 - N[(N[Cos[x], $MachinePrecision] + t$95$1), $MachinePrecision]), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos x \cdot \cos \varepsilon\\
t_1 := \sin \varepsilon \cdot \sin x\\
\mathbf{if}\;\varepsilon \leq -0.0055:\\
\;\;\;\;\left(t_0 - \cos x\right) - t_1\\

\mathbf{elif}\;\varepsilon \leq 0.0052:\\
\;\;\;\;\cos x \cdot \left(-0.5 \cdot {\varepsilon}^{2} + 0.041666666666666664 \cdot {\varepsilon}^{4}\right) - t_1\\

\mathbf{else}:\\
\;\;\;\;t_0 - \left(\cos x + t_1\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if eps < -0.0054999999999999997

    1. Initial program 62.6%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. cos-sum98.7%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \]
      2. cancel-sign-sub-inv98.7%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
      3. fma-def98.7%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    4. Applied egg-rr98.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    5. Taylor expanded in x around inf 98.7%

      \[\leadsto \color{blue}{\left(-1 \cdot \left(\sin \varepsilon \cdot \sin x\right) + \cos \varepsilon \cdot \cos x\right) - \cos x} \]
    6. Step-by-step derivation
      1. neg-mul-198.7%

        \[\leadsto \left(\color{blue}{\left(-\sin \varepsilon \cdot \sin x\right)} + \cos \varepsilon \cdot \cos x\right) - \cos x \]
      2. +-commutative98.7%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + \left(-\sin \varepsilon \cdot \sin x\right)\right)} - \cos x \]
      3. sub-neg98.7%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x - \sin \varepsilon \cdot \sin x\right)} - \cos x \]
      4. *-commutative98.7%

        \[\leadsto \left(\color{blue}{\cos x \cdot \cos \varepsilon} - \sin \varepsilon \cdot \sin x\right) - \cos x \]
      5. associate--r+98.7%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \sin x + \cos x\right)} \]
      6. +-commutative98.7%

        \[\leadsto \cos x \cdot \cos \varepsilon - \color{blue}{\left(\cos x + \sin \varepsilon \cdot \sin x\right)} \]
      7. associate--r+98.8%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \cos x\right) - \sin \varepsilon \cdot \sin x} \]
      8. *-rgt-identity98.8%

        \[\leadsto \left(\cos x \cdot \cos \varepsilon - \color{blue}{\cos x \cdot 1}\right) - \sin \varepsilon \cdot \sin x \]
      9. distribute-lft-out--98.8%

        \[\leadsto \color{blue}{\cos x \cdot \left(\cos \varepsilon - 1\right)} - \sin \varepsilon \cdot \sin x \]
      10. sub-neg98.8%

        \[\leadsto \cos x \cdot \color{blue}{\left(\cos \varepsilon + \left(-1\right)\right)} - \sin \varepsilon \cdot \sin x \]
      11. metadata-eval98.8%

        \[\leadsto \cos x \cdot \left(\cos \varepsilon + \color{blue}{-1}\right) - \sin \varepsilon \cdot \sin x \]
      12. +-commutative98.8%

        \[\leadsto \cos x \cdot \color{blue}{\left(-1 + \cos \varepsilon\right)} - \sin \varepsilon \cdot \sin x \]
      13. *-commutative98.8%

        \[\leadsto \cos x \cdot \left(-1 + \cos \varepsilon\right) - \color{blue}{\sin x \cdot \sin \varepsilon} \]
    7. Simplified98.8%

      \[\leadsto \color{blue}{\cos x \cdot \left(-1 + \cos \varepsilon\right) - \sin x \cdot \sin \varepsilon} \]
    8. Step-by-step derivation
      1. +-commutative98.8%

        \[\leadsto \cos x \cdot \color{blue}{\left(\cos \varepsilon + -1\right)} - \sin x \cdot \sin \varepsilon \]
      2. distribute-rgt-in98.8%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + -1 \cdot \cos x\right)} - \sin x \cdot \sin \varepsilon \]
      3. neg-mul-198.8%

        \[\leadsto \left(\cos \varepsilon \cdot \cos x + \color{blue}{\left(-\cos x\right)}\right) - \sin x \cdot \sin \varepsilon \]
    9. Applied egg-rr98.8%

      \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + \left(-\cos x\right)\right)} - \sin x \cdot \sin \varepsilon \]
    10. Taylor expanded in eps around inf 98.8%

      \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x - \cos x\right)} - \sin x \cdot \sin \varepsilon \]

    if -0.0054999999999999997 < eps < 0.0051999999999999998

    1. Initial program 24.9%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. cos-sum26.1%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \]
      2. cancel-sign-sub-inv26.1%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
      3. fma-def26.1%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    4. Applied egg-rr26.1%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    5. Taylor expanded in x around inf 26.1%

      \[\leadsto \color{blue}{\left(-1 \cdot \left(\sin \varepsilon \cdot \sin x\right) + \cos \varepsilon \cdot \cos x\right) - \cos x} \]
    6. Step-by-step derivation
      1. neg-mul-126.1%

        \[\leadsto \left(\color{blue}{\left(-\sin \varepsilon \cdot \sin x\right)} + \cos \varepsilon \cdot \cos x\right) - \cos x \]
      2. +-commutative26.1%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + \left(-\sin \varepsilon \cdot \sin x\right)\right)} - \cos x \]
      3. sub-neg26.1%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x - \sin \varepsilon \cdot \sin x\right)} - \cos x \]
      4. *-commutative26.1%

        \[\leadsto \left(\color{blue}{\cos x \cdot \cos \varepsilon} - \sin \varepsilon \cdot \sin x\right) - \cos x \]
      5. associate--r+26.1%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \sin x + \cos x\right)} \]
      6. +-commutative26.1%

        \[\leadsto \cos x \cdot \cos \varepsilon - \color{blue}{\left(\cos x + \sin \varepsilon \cdot \sin x\right)} \]
      7. associate--r+83.4%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \cos x\right) - \sin \varepsilon \cdot \sin x} \]
      8. *-rgt-identity83.4%

        \[\leadsto \left(\cos x \cdot \cos \varepsilon - \color{blue}{\cos x \cdot 1}\right) - \sin \varepsilon \cdot \sin x \]
      9. distribute-lft-out--83.4%

        \[\leadsto \color{blue}{\cos x \cdot \left(\cos \varepsilon - 1\right)} - \sin \varepsilon \cdot \sin x \]
      10. sub-neg83.4%

        \[\leadsto \cos x \cdot \color{blue}{\left(\cos \varepsilon + \left(-1\right)\right)} - \sin \varepsilon \cdot \sin x \]
      11. metadata-eval83.4%

        \[\leadsto \cos x \cdot \left(\cos \varepsilon + \color{blue}{-1}\right) - \sin \varepsilon \cdot \sin x \]
      12. +-commutative83.4%

        \[\leadsto \cos x \cdot \color{blue}{\left(-1 + \cos \varepsilon\right)} - \sin \varepsilon \cdot \sin x \]
      13. *-commutative83.4%

        \[\leadsto \cos x \cdot \left(-1 + \cos \varepsilon\right) - \color{blue}{\sin x \cdot \sin \varepsilon} \]
    7. Simplified83.4%

      \[\leadsto \color{blue}{\cos x \cdot \left(-1 + \cos \varepsilon\right) - \sin x \cdot \sin \varepsilon} \]
    8. Taylor expanded in eps around 0 99.8%

      \[\leadsto \cos x \cdot \color{blue}{\left(-0.5 \cdot {\varepsilon}^{2} + 0.041666666666666664 \cdot {\varepsilon}^{4}\right)} - \sin x \cdot \sin \varepsilon \]

    if 0.0051999999999999998 < eps

    1. Initial program 49.8%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. add-log-exp49.8%

        \[\leadsto \color{blue}{\log \left(e^{\cos \left(x + \varepsilon\right) - \cos x}\right)} \]
    4. Applied egg-rr49.8%

      \[\leadsto \color{blue}{\log \left(e^{\cos \left(x + \varepsilon\right) - \cos x}\right)} \]
    5. Step-by-step derivation
      1. rem-log-exp49.8%

        \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) - \cos x} \]
      2. cos-sum99.1%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \]
      3. associate--l-99.1%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin x \cdot \sin \varepsilon + \cos x\right)} \]
      4. add-sqr-sqrt48.2%

        \[\leadsto \cos x \cdot \cos \varepsilon - \left(\color{blue}{\left(\sqrt{\sin x} \cdot \sqrt{\sin x}\right)} \cdot \sin \varepsilon + \cos x\right) \]
      5. sqrt-unprod75.4%

        \[\leadsto \cos x \cdot \cos \varepsilon - \left(\color{blue}{\sqrt{\sin x \cdot \sin x}} \cdot \sin \varepsilon + \cos x\right) \]
      6. sqr-neg75.4%

        \[\leadsto \cos x \cdot \cos \varepsilon - \left(\sqrt{\color{blue}{\left(-\sin x\right) \cdot \left(-\sin x\right)}} \cdot \sin \varepsilon + \cos x\right) \]
      7. sqrt-unprod27.2%

        \[\leadsto \cos x \cdot \cos \varepsilon - \left(\color{blue}{\left(\sqrt{-\sin x} \cdot \sqrt{-\sin x}\right)} \cdot \sin \varepsilon + \cos x\right) \]
      8. add-sqr-sqrt51.6%

        \[\leadsto \cos x \cdot \cos \varepsilon - \left(\color{blue}{\left(-\sin x\right)} \cdot \sin \varepsilon + \cos x\right) \]
      9. *-commutative51.6%

        \[\leadsto \cos x \cdot \cos \varepsilon - \left(\color{blue}{\sin \varepsilon \cdot \left(-\sin x\right)} + \cos x\right) \]
      10. add-sqr-sqrt27.2%

        \[\leadsto \cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \color{blue}{\left(\sqrt{-\sin x} \cdot \sqrt{-\sin x}\right)} + \cos x\right) \]
      11. sqrt-unprod75.4%

        \[\leadsto \cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \color{blue}{\sqrt{\left(-\sin x\right) \cdot \left(-\sin x\right)}} + \cos x\right) \]
      12. sqr-neg75.4%

        \[\leadsto \cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \sqrt{\color{blue}{\sin x \cdot \sin x}} + \cos x\right) \]
      13. sqrt-unprod48.2%

        \[\leadsto \cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \color{blue}{\left(\sqrt{\sin x} \cdot \sqrt{\sin x}\right)} + \cos x\right) \]
      14. add-sqr-sqrt99.1%

        \[\leadsto \cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \color{blue}{\sin x} + \cos x\right) \]
    6. Applied egg-rr99.1%

      \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \sin x + \cos x\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.0055:\\ \;\;\;\;\left(\cos x \cdot \cos \varepsilon - \cos x\right) - \sin \varepsilon \cdot \sin x\\ \mathbf{elif}\;\varepsilon \leq 0.0052:\\ \;\;\;\;\cos x \cdot \left(-0.5 \cdot {\varepsilon}^{2} + 0.041666666666666664 \cdot {\varepsilon}^{4}\right) - \sin \varepsilon \cdot \sin x\\ \mathbf{else}:\\ \;\;\;\;\cos x \cdot \cos \varepsilon - \left(\cos x + \sin \varepsilon \cdot \sin x\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 99.1% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -6.4 \cdot 10^{-15}:\\ \;\;\;\;\mathsf{fma}\left(-1 + \cos \varepsilon, \cos x, \sin \varepsilon \cdot \left(-\sin x\right)\right)\\ \mathbf{elif}\;x \leq 4.8 \cdot 10^{-33}:\\ \;\;\;\;\left(\sin \left(\left(\varepsilon + \left(x - x\right)\right) \cdot 0.5\right) \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)\right) \cdot -2\\ \mathbf{else}:\\ \;\;\;\;\left(\cos x \cdot \cos \varepsilon - \cos x\right) - \sin \varepsilon \cdot \sin x\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (<= x -6.4e-15)
   (fma (+ -1.0 (cos eps)) (cos x) (* (sin eps) (- (sin x))))
   (if (<= x 4.8e-33)
     (* (* (sin (* (+ eps (- x x)) 0.5)) (sin (* 0.5 (+ eps (+ x x))))) -2.0)
     (- (- (* (cos x) (cos eps)) (cos x)) (* (sin eps) (sin x))))))
double code(double x, double eps) {
	double tmp;
	if (x <= -6.4e-15) {
		tmp = fma((-1.0 + cos(eps)), cos(x), (sin(eps) * -sin(x)));
	} else if (x <= 4.8e-33) {
		tmp = (sin(((eps + (x - x)) * 0.5)) * sin((0.5 * (eps + (x + x))))) * -2.0;
	} else {
		tmp = ((cos(x) * cos(eps)) - cos(x)) - (sin(eps) * sin(x));
	}
	return tmp;
}
function code(x, eps)
	tmp = 0.0
	if (x <= -6.4e-15)
		tmp = fma(Float64(-1.0 + cos(eps)), cos(x), Float64(sin(eps) * Float64(-sin(x))));
	elseif (x <= 4.8e-33)
		tmp = Float64(Float64(sin(Float64(Float64(eps + Float64(x - x)) * 0.5)) * sin(Float64(0.5 * Float64(eps + Float64(x + x))))) * -2.0);
	else
		tmp = Float64(Float64(Float64(cos(x) * cos(eps)) - cos(x)) - Float64(sin(eps) * sin(x)));
	end
	return tmp
end
code[x_, eps_] := If[LessEqual[x, -6.4e-15], N[(N[(-1.0 + N[Cos[eps], $MachinePrecision]), $MachinePrecision] * N[Cos[x], $MachinePrecision] + N[(N[Sin[eps], $MachinePrecision] * (-N[Sin[x], $MachinePrecision])), $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 4.8e-33], N[(N[(N[Sin[N[(N[(eps + N[(x - x), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision]], $MachinePrecision] * N[Sin[N[(0.5 * N[(eps + N[(x + x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * -2.0), $MachinePrecision], N[(N[(N[(N[Cos[x], $MachinePrecision] * N[Cos[eps], $MachinePrecision]), $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision] - N[(N[Sin[eps], $MachinePrecision] * N[Sin[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -6.4 \cdot 10^{-15}:\\
\;\;\;\;\mathsf{fma}\left(-1 + \cos \varepsilon, \cos x, \sin \varepsilon \cdot \left(-\sin x\right)\right)\\

\mathbf{elif}\;x \leq 4.8 \cdot 10^{-33}:\\
\;\;\;\;\left(\sin \left(\left(\varepsilon + \left(x - x\right)\right) \cdot 0.5\right) \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)\right) \cdot -2\\

\mathbf{else}:\\
\;\;\;\;\left(\cos x \cdot \cos \varepsilon - \cos x\right) - \sin \varepsilon \cdot \sin x\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -6.3999999999999999e-15

    1. Initial program 9.2%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. cos-sum50.7%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \]
      2. cancel-sign-sub-inv50.7%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
      3. fma-def50.7%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    4. Applied egg-rr50.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    5. Taylor expanded in x around inf 50.7%

      \[\leadsto \color{blue}{\left(-1 \cdot \left(\sin \varepsilon \cdot \sin x\right) + \cos \varepsilon \cdot \cos x\right) - \cos x} \]
    6. Step-by-step derivation
      1. neg-mul-150.7%

        \[\leadsto \left(\color{blue}{\left(-\sin \varepsilon \cdot \sin x\right)} + \cos \varepsilon \cdot \cos x\right) - \cos x \]
      2. +-commutative50.7%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + \left(-\sin \varepsilon \cdot \sin x\right)\right)} - \cos x \]
      3. sub-neg50.7%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x - \sin \varepsilon \cdot \sin x\right)} - \cos x \]
      4. *-commutative50.7%

        \[\leadsto \left(\color{blue}{\cos x \cdot \cos \varepsilon} - \sin \varepsilon \cdot \sin x\right) - \cos x \]
      5. associate--r+50.6%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \sin x + \cos x\right)} \]
      6. +-commutative50.6%

        \[\leadsto \cos x \cdot \cos \varepsilon - \color{blue}{\left(\cos x + \sin \varepsilon \cdot \sin x\right)} \]
      7. associate--r+99.5%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \cos x\right) - \sin \varepsilon \cdot \sin x} \]
      8. *-rgt-identity99.5%

        \[\leadsto \left(\cos x \cdot \cos \varepsilon - \color{blue}{\cos x \cdot 1}\right) - \sin \varepsilon \cdot \sin x \]
      9. distribute-lft-out--99.5%

        \[\leadsto \color{blue}{\cos x \cdot \left(\cos \varepsilon - 1\right)} - \sin \varepsilon \cdot \sin x \]
      10. sub-neg99.5%

        \[\leadsto \cos x \cdot \color{blue}{\left(\cos \varepsilon + \left(-1\right)\right)} - \sin \varepsilon \cdot \sin x \]
      11. metadata-eval99.5%

        \[\leadsto \cos x \cdot \left(\cos \varepsilon + \color{blue}{-1}\right) - \sin \varepsilon \cdot \sin x \]
      12. +-commutative99.5%

        \[\leadsto \cos x \cdot \color{blue}{\left(-1 + \cos \varepsilon\right)} - \sin \varepsilon \cdot \sin x \]
      13. *-commutative99.5%

        \[\leadsto \cos x \cdot \left(-1 + \cos \varepsilon\right) - \color{blue}{\sin x \cdot \sin \varepsilon} \]
    7. Simplified99.5%

      \[\leadsto \color{blue}{\cos x \cdot \left(-1 + \cos \varepsilon\right) - \sin x \cdot \sin \varepsilon} \]
    8. Step-by-step derivation
      1. *-commutative99.5%

        \[\leadsto \color{blue}{\left(-1 + \cos \varepsilon\right) \cdot \cos x} - \sin x \cdot \sin \varepsilon \]
      2. fma-neg99.5%

        \[\leadsto \color{blue}{\mathsf{fma}\left(-1 + \cos \varepsilon, \cos x, -\sin x \cdot \sin \varepsilon\right)} \]
      3. distribute-rgt-neg-in99.5%

        \[\leadsto \mathsf{fma}\left(-1 + \cos \varepsilon, \cos x, \color{blue}{\sin x \cdot \left(-\sin \varepsilon\right)}\right) \]
    9. Applied egg-rr99.5%

      \[\leadsto \color{blue}{\mathsf{fma}\left(-1 + \cos \varepsilon, \cos x, \sin x \cdot \left(-\sin \varepsilon\right)\right)} \]

    if -6.3999999999999999e-15 < x < 4.8e-33

    1. Initial program 77.0%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. cos-sum77.0%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \]
      2. cancel-sign-sub-inv77.0%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
      3. fma-def77.0%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    4. Applied egg-rr77.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    5. Taylor expanded in x around inf 77.0%

      \[\leadsto \color{blue}{\left(-1 \cdot \left(\sin \varepsilon \cdot \sin x\right) + \cos \varepsilon \cdot \cos x\right) - \cos x} \]
    6. Step-by-step derivation
      1. neg-mul-177.0%

        \[\leadsto \left(\color{blue}{\left(-\sin \varepsilon \cdot \sin x\right)} + \cos \varepsilon \cdot \cos x\right) - \cos x \]
      2. +-commutative77.0%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + \left(-\sin \varepsilon \cdot \sin x\right)\right)} - \cos x \]
      3. sub-neg77.0%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x - \sin \varepsilon \cdot \sin x\right)} - \cos x \]
      4. *-commutative77.0%

        \[\leadsto \left(\color{blue}{\cos x \cdot \cos \varepsilon} - \sin \varepsilon \cdot \sin x\right) - \cos x \]
      5. associate--r+77.0%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \sin x + \cos x\right)} \]
      6. +-commutative77.0%

        \[\leadsto \cos x \cdot \cos \varepsilon - \color{blue}{\left(\cos x + \sin \varepsilon \cdot \sin x\right)} \]
      7. associate--r+81.7%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \cos x\right) - \sin \varepsilon \cdot \sin x} \]
      8. *-rgt-identity81.7%

        \[\leadsto \left(\cos x \cdot \cos \varepsilon - \color{blue}{\cos x \cdot 1}\right) - \sin \varepsilon \cdot \sin x \]
      9. distribute-lft-out--81.7%

        \[\leadsto \color{blue}{\cos x \cdot \left(\cos \varepsilon - 1\right)} - \sin \varepsilon \cdot \sin x \]
      10. sub-neg81.7%

        \[\leadsto \cos x \cdot \color{blue}{\left(\cos \varepsilon + \left(-1\right)\right)} - \sin \varepsilon \cdot \sin x \]
      11. metadata-eval81.7%

        \[\leadsto \cos x \cdot \left(\cos \varepsilon + \color{blue}{-1}\right) - \sin \varepsilon \cdot \sin x \]
      12. +-commutative81.7%

        \[\leadsto \cos x \cdot \color{blue}{\left(-1 + \cos \varepsilon\right)} - \sin \varepsilon \cdot \sin x \]
      13. *-commutative81.7%

        \[\leadsto \cos x \cdot \left(-1 + \cos \varepsilon\right) - \color{blue}{\sin x \cdot \sin \varepsilon} \]
    7. Simplified81.7%

      \[\leadsto \color{blue}{\cos x \cdot \left(-1 + \cos \varepsilon\right) - \sin x \cdot \sin \varepsilon} \]
    8. Step-by-step derivation
      1. distribute-lft-in81.7%

        \[\leadsto \color{blue}{\left(\cos x \cdot -1 + \cos x \cdot \cos \varepsilon\right)} - \sin x \cdot \sin \varepsilon \]
      2. associate--l+77.0%

        \[\leadsto \color{blue}{\cos x \cdot -1 + \left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} \]
      3. *-commutative77.0%

        \[\leadsto \color{blue}{-1 \cdot \cos x} + \left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right) \]
      4. neg-mul-177.0%

        \[\leadsto \color{blue}{\left(-\cos x\right)} + \left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right) \]
      5. cos-sum77.0%

        \[\leadsto \left(-\cos x\right) + \color{blue}{\cos \left(x + \varepsilon\right)} \]
      6. +-commutative77.0%

        \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) + \left(-\cos x\right)} \]
      7. sub-neg77.0%

        \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) - \cos x} \]
      8. diff-cos94.9%

        \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      9. *-commutative94.9%

        \[\leadsto \color{blue}{\left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \cdot -2} \]
    9. Applied egg-rr99.6%

      \[\leadsto \color{blue}{\left(\sin \left(\left(\varepsilon + \left(x - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right) \cdot -2} \]

    if 4.8e-33 < x

    1. Initial program 11.0%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. cos-sum53.0%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \]
      2. cancel-sign-sub-inv53.0%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
      3. fma-def53.0%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    4. Applied egg-rr53.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    5. Taylor expanded in x around inf 53.0%

      \[\leadsto \color{blue}{\left(-1 \cdot \left(\sin \varepsilon \cdot \sin x\right) + \cos \varepsilon \cdot \cos x\right) - \cos x} \]
    6. Step-by-step derivation
      1. neg-mul-153.0%

        \[\leadsto \left(\color{blue}{\left(-\sin \varepsilon \cdot \sin x\right)} + \cos \varepsilon \cdot \cos x\right) - \cos x \]
      2. +-commutative53.0%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + \left(-\sin \varepsilon \cdot \sin x\right)\right)} - \cos x \]
      3. sub-neg53.0%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x - \sin \varepsilon \cdot \sin x\right)} - \cos x \]
      4. *-commutative53.0%

        \[\leadsto \left(\color{blue}{\cos x \cdot \cos \varepsilon} - \sin \varepsilon \cdot \sin x\right) - \cos x \]
      5. associate--r+53.0%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \sin x + \cos x\right)} \]
      6. +-commutative53.0%

        \[\leadsto \cos x \cdot \cos \varepsilon - \color{blue}{\left(\cos x + \sin \varepsilon \cdot \sin x\right)} \]
      7. associate--r+98.8%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \cos x\right) - \sin \varepsilon \cdot \sin x} \]
      8. *-rgt-identity98.8%

        \[\leadsto \left(\cos x \cdot \cos \varepsilon - \color{blue}{\cos x \cdot 1}\right) - \sin \varepsilon \cdot \sin x \]
      9. distribute-lft-out--98.7%

        \[\leadsto \color{blue}{\cos x \cdot \left(\cos \varepsilon - 1\right)} - \sin \varepsilon \cdot \sin x \]
      10. sub-neg98.7%

        \[\leadsto \cos x \cdot \color{blue}{\left(\cos \varepsilon + \left(-1\right)\right)} - \sin \varepsilon \cdot \sin x \]
      11. metadata-eval98.7%

        \[\leadsto \cos x \cdot \left(\cos \varepsilon + \color{blue}{-1}\right) - \sin \varepsilon \cdot \sin x \]
      12. +-commutative98.7%

        \[\leadsto \cos x \cdot \color{blue}{\left(-1 + \cos \varepsilon\right)} - \sin \varepsilon \cdot \sin x \]
      13. *-commutative98.7%

        \[\leadsto \cos x \cdot \left(-1 + \cos \varepsilon\right) - \color{blue}{\sin x \cdot \sin \varepsilon} \]
    7. Simplified98.7%

      \[\leadsto \color{blue}{\cos x \cdot \left(-1 + \cos \varepsilon\right) - \sin x \cdot \sin \varepsilon} \]
    8. Step-by-step derivation
      1. +-commutative98.7%

        \[\leadsto \cos x \cdot \color{blue}{\left(\cos \varepsilon + -1\right)} - \sin x \cdot \sin \varepsilon \]
      2. distribute-rgt-in98.8%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + -1 \cdot \cos x\right)} - \sin x \cdot \sin \varepsilon \]
      3. neg-mul-198.8%

        \[\leadsto \left(\cos \varepsilon \cdot \cos x + \color{blue}{\left(-\cos x\right)}\right) - \sin x \cdot \sin \varepsilon \]
    9. Applied egg-rr98.8%

      \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + \left(-\cos x\right)\right)} - \sin x \cdot \sin \varepsilon \]
    10. Taylor expanded in eps around inf 98.8%

      \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x - \cos x\right)} - \sin x \cdot \sin \varepsilon \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -6.4 \cdot 10^{-15}:\\ \;\;\;\;\mathsf{fma}\left(-1 + \cos \varepsilon, \cos x, \sin \varepsilon \cdot \left(-\sin x\right)\right)\\ \mathbf{elif}\;x \leq 4.8 \cdot 10^{-33}:\\ \;\;\;\;\left(\sin \left(\left(\varepsilon + \left(x - x\right)\right) \cdot 0.5\right) \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)\right) \cdot -2\\ \mathbf{else}:\\ \;\;\;\;\left(\cos x \cdot \cos \varepsilon - \cos x\right) - \sin \varepsilon \cdot \sin x\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 99.1% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := -1 + \cos \varepsilon\\ \mathbf{if}\;x \leq -2.05 \cdot 10^{-14}:\\ \;\;\;\;\mathsf{fma}\left(t_0, \cos x, \sin \varepsilon \cdot \left(-\sin x\right)\right)\\ \mathbf{elif}\;x \leq 1.6 \cdot 10^{-34}:\\ \;\;\;\;\left(\sin \left(\left(\varepsilon + \left(x - x\right)\right) \cdot 0.5\right) \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)\right) \cdot -2\\ \mathbf{else}:\\ \;\;\;\;\cos x \cdot t_0 - \sin \varepsilon \cdot \sin x\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (+ -1.0 (cos eps))))
   (if (<= x -2.05e-14)
     (fma t_0 (cos x) (* (sin eps) (- (sin x))))
     (if (<= x 1.6e-34)
       (* (* (sin (* (+ eps (- x x)) 0.5)) (sin (* 0.5 (+ eps (+ x x))))) -2.0)
       (- (* (cos x) t_0) (* (sin eps) (sin x)))))))
double code(double x, double eps) {
	double t_0 = -1.0 + cos(eps);
	double tmp;
	if (x <= -2.05e-14) {
		tmp = fma(t_0, cos(x), (sin(eps) * -sin(x)));
	} else if (x <= 1.6e-34) {
		tmp = (sin(((eps + (x - x)) * 0.5)) * sin((0.5 * (eps + (x + x))))) * -2.0;
	} else {
		tmp = (cos(x) * t_0) - (sin(eps) * sin(x));
	}
	return tmp;
}
function code(x, eps)
	t_0 = Float64(-1.0 + cos(eps))
	tmp = 0.0
	if (x <= -2.05e-14)
		tmp = fma(t_0, cos(x), Float64(sin(eps) * Float64(-sin(x))));
	elseif (x <= 1.6e-34)
		tmp = Float64(Float64(sin(Float64(Float64(eps + Float64(x - x)) * 0.5)) * sin(Float64(0.5 * Float64(eps + Float64(x + x))))) * -2.0);
	else
		tmp = Float64(Float64(cos(x) * t_0) - Float64(sin(eps) * sin(x)));
	end
	return tmp
end
code[x_, eps_] := Block[{t$95$0 = N[(-1.0 + N[Cos[eps], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[x, -2.05e-14], N[(t$95$0 * N[Cos[x], $MachinePrecision] + N[(N[Sin[eps], $MachinePrecision] * (-N[Sin[x], $MachinePrecision])), $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 1.6e-34], N[(N[(N[Sin[N[(N[(eps + N[(x - x), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision]], $MachinePrecision] * N[Sin[N[(0.5 * N[(eps + N[(x + x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * -2.0), $MachinePrecision], N[(N[(N[Cos[x], $MachinePrecision] * t$95$0), $MachinePrecision] - N[(N[Sin[eps], $MachinePrecision] * N[Sin[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := -1 + \cos \varepsilon\\
\mathbf{if}\;x \leq -2.05 \cdot 10^{-14}:\\
\;\;\;\;\mathsf{fma}\left(t_0, \cos x, \sin \varepsilon \cdot \left(-\sin x\right)\right)\\

\mathbf{elif}\;x \leq 1.6 \cdot 10^{-34}:\\
\;\;\;\;\left(\sin \left(\left(\varepsilon + \left(x - x\right)\right) \cdot 0.5\right) \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)\right) \cdot -2\\

\mathbf{else}:\\
\;\;\;\;\cos x \cdot t_0 - \sin \varepsilon \cdot \sin x\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -2.0500000000000001e-14

    1. Initial program 9.2%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. cos-sum50.7%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \]
      2. cancel-sign-sub-inv50.7%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
      3. fma-def50.7%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    4. Applied egg-rr50.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    5. Taylor expanded in x around inf 50.7%

      \[\leadsto \color{blue}{\left(-1 \cdot \left(\sin \varepsilon \cdot \sin x\right) + \cos \varepsilon \cdot \cos x\right) - \cos x} \]
    6. Step-by-step derivation
      1. neg-mul-150.7%

        \[\leadsto \left(\color{blue}{\left(-\sin \varepsilon \cdot \sin x\right)} + \cos \varepsilon \cdot \cos x\right) - \cos x \]
      2. +-commutative50.7%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + \left(-\sin \varepsilon \cdot \sin x\right)\right)} - \cos x \]
      3. sub-neg50.7%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x - \sin \varepsilon \cdot \sin x\right)} - \cos x \]
      4. *-commutative50.7%

        \[\leadsto \left(\color{blue}{\cos x \cdot \cos \varepsilon} - \sin \varepsilon \cdot \sin x\right) - \cos x \]
      5. associate--r+50.6%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \sin x + \cos x\right)} \]
      6. +-commutative50.6%

        \[\leadsto \cos x \cdot \cos \varepsilon - \color{blue}{\left(\cos x + \sin \varepsilon \cdot \sin x\right)} \]
      7. associate--r+99.5%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \cos x\right) - \sin \varepsilon \cdot \sin x} \]
      8. *-rgt-identity99.5%

        \[\leadsto \left(\cos x \cdot \cos \varepsilon - \color{blue}{\cos x \cdot 1}\right) - \sin \varepsilon \cdot \sin x \]
      9. distribute-lft-out--99.5%

        \[\leadsto \color{blue}{\cos x \cdot \left(\cos \varepsilon - 1\right)} - \sin \varepsilon \cdot \sin x \]
      10. sub-neg99.5%

        \[\leadsto \cos x \cdot \color{blue}{\left(\cos \varepsilon + \left(-1\right)\right)} - \sin \varepsilon \cdot \sin x \]
      11. metadata-eval99.5%

        \[\leadsto \cos x \cdot \left(\cos \varepsilon + \color{blue}{-1}\right) - \sin \varepsilon \cdot \sin x \]
      12. +-commutative99.5%

        \[\leadsto \cos x \cdot \color{blue}{\left(-1 + \cos \varepsilon\right)} - \sin \varepsilon \cdot \sin x \]
      13. *-commutative99.5%

        \[\leadsto \cos x \cdot \left(-1 + \cos \varepsilon\right) - \color{blue}{\sin x \cdot \sin \varepsilon} \]
    7. Simplified99.5%

      \[\leadsto \color{blue}{\cos x \cdot \left(-1 + \cos \varepsilon\right) - \sin x \cdot \sin \varepsilon} \]
    8. Step-by-step derivation
      1. *-commutative99.5%

        \[\leadsto \color{blue}{\left(-1 + \cos \varepsilon\right) \cdot \cos x} - \sin x \cdot \sin \varepsilon \]
      2. fma-neg99.5%

        \[\leadsto \color{blue}{\mathsf{fma}\left(-1 + \cos \varepsilon, \cos x, -\sin x \cdot \sin \varepsilon\right)} \]
      3. distribute-rgt-neg-in99.5%

        \[\leadsto \mathsf{fma}\left(-1 + \cos \varepsilon, \cos x, \color{blue}{\sin x \cdot \left(-\sin \varepsilon\right)}\right) \]
    9. Applied egg-rr99.5%

      \[\leadsto \color{blue}{\mathsf{fma}\left(-1 + \cos \varepsilon, \cos x, \sin x \cdot \left(-\sin \varepsilon\right)\right)} \]

    if -2.0500000000000001e-14 < x < 1.60000000000000001e-34

    1. Initial program 77.0%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. cos-sum77.0%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \]
      2. cancel-sign-sub-inv77.0%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
      3. fma-def77.0%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    4. Applied egg-rr77.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    5. Taylor expanded in x around inf 77.0%

      \[\leadsto \color{blue}{\left(-1 \cdot \left(\sin \varepsilon \cdot \sin x\right) + \cos \varepsilon \cdot \cos x\right) - \cos x} \]
    6. Step-by-step derivation
      1. neg-mul-177.0%

        \[\leadsto \left(\color{blue}{\left(-\sin \varepsilon \cdot \sin x\right)} + \cos \varepsilon \cdot \cos x\right) - \cos x \]
      2. +-commutative77.0%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + \left(-\sin \varepsilon \cdot \sin x\right)\right)} - \cos x \]
      3. sub-neg77.0%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x - \sin \varepsilon \cdot \sin x\right)} - \cos x \]
      4. *-commutative77.0%

        \[\leadsto \left(\color{blue}{\cos x \cdot \cos \varepsilon} - \sin \varepsilon \cdot \sin x\right) - \cos x \]
      5. associate--r+77.0%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \sin x + \cos x\right)} \]
      6. +-commutative77.0%

        \[\leadsto \cos x \cdot \cos \varepsilon - \color{blue}{\left(\cos x + \sin \varepsilon \cdot \sin x\right)} \]
      7. associate--r+81.7%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \cos x\right) - \sin \varepsilon \cdot \sin x} \]
      8. *-rgt-identity81.7%

        \[\leadsto \left(\cos x \cdot \cos \varepsilon - \color{blue}{\cos x \cdot 1}\right) - \sin \varepsilon \cdot \sin x \]
      9. distribute-lft-out--81.7%

        \[\leadsto \color{blue}{\cos x \cdot \left(\cos \varepsilon - 1\right)} - \sin \varepsilon \cdot \sin x \]
      10. sub-neg81.7%

        \[\leadsto \cos x \cdot \color{blue}{\left(\cos \varepsilon + \left(-1\right)\right)} - \sin \varepsilon \cdot \sin x \]
      11. metadata-eval81.7%

        \[\leadsto \cos x \cdot \left(\cos \varepsilon + \color{blue}{-1}\right) - \sin \varepsilon \cdot \sin x \]
      12. +-commutative81.7%

        \[\leadsto \cos x \cdot \color{blue}{\left(-1 + \cos \varepsilon\right)} - \sin \varepsilon \cdot \sin x \]
      13. *-commutative81.7%

        \[\leadsto \cos x \cdot \left(-1 + \cos \varepsilon\right) - \color{blue}{\sin x \cdot \sin \varepsilon} \]
    7. Simplified81.7%

      \[\leadsto \color{blue}{\cos x \cdot \left(-1 + \cos \varepsilon\right) - \sin x \cdot \sin \varepsilon} \]
    8. Step-by-step derivation
      1. distribute-lft-in81.7%

        \[\leadsto \color{blue}{\left(\cos x \cdot -1 + \cos x \cdot \cos \varepsilon\right)} - \sin x \cdot \sin \varepsilon \]
      2. associate--l+77.0%

        \[\leadsto \color{blue}{\cos x \cdot -1 + \left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} \]
      3. *-commutative77.0%

        \[\leadsto \color{blue}{-1 \cdot \cos x} + \left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right) \]
      4. neg-mul-177.0%

        \[\leadsto \color{blue}{\left(-\cos x\right)} + \left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right) \]
      5. cos-sum77.0%

        \[\leadsto \left(-\cos x\right) + \color{blue}{\cos \left(x + \varepsilon\right)} \]
      6. +-commutative77.0%

        \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) + \left(-\cos x\right)} \]
      7. sub-neg77.0%

        \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) - \cos x} \]
      8. diff-cos94.9%

        \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      9. *-commutative94.9%

        \[\leadsto \color{blue}{\left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \cdot -2} \]
    9. Applied egg-rr99.6%

      \[\leadsto \color{blue}{\left(\sin \left(\left(\varepsilon + \left(x - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right) \cdot -2} \]

    if 1.60000000000000001e-34 < x

    1. Initial program 11.0%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. cos-sum53.0%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \]
      2. cancel-sign-sub-inv53.0%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
      3. fma-def53.0%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    4. Applied egg-rr53.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    5. Taylor expanded in x around inf 53.0%

      \[\leadsto \color{blue}{\left(-1 \cdot \left(\sin \varepsilon \cdot \sin x\right) + \cos \varepsilon \cdot \cos x\right) - \cos x} \]
    6. Step-by-step derivation
      1. neg-mul-153.0%

        \[\leadsto \left(\color{blue}{\left(-\sin \varepsilon \cdot \sin x\right)} + \cos \varepsilon \cdot \cos x\right) - \cos x \]
      2. +-commutative53.0%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + \left(-\sin \varepsilon \cdot \sin x\right)\right)} - \cos x \]
      3. sub-neg53.0%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x - \sin \varepsilon \cdot \sin x\right)} - \cos x \]
      4. *-commutative53.0%

        \[\leadsto \left(\color{blue}{\cos x \cdot \cos \varepsilon} - \sin \varepsilon \cdot \sin x\right) - \cos x \]
      5. associate--r+53.0%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \sin x + \cos x\right)} \]
      6. +-commutative53.0%

        \[\leadsto \cos x \cdot \cos \varepsilon - \color{blue}{\left(\cos x + \sin \varepsilon \cdot \sin x\right)} \]
      7. associate--r+98.8%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \cos x\right) - \sin \varepsilon \cdot \sin x} \]
      8. *-rgt-identity98.8%

        \[\leadsto \left(\cos x \cdot \cos \varepsilon - \color{blue}{\cos x \cdot 1}\right) - \sin \varepsilon \cdot \sin x \]
      9. distribute-lft-out--98.7%

        \[\leadsto \color{blue}{\cos x \cdot \left(\cos \varepsilon - 1\right)} - \sin \varepsilon \cdot \sin x \]
      10. sub-neg98.7%

        \[\leadsto \cos x \cdot \color{blue}{\left(\cos \varepsilon + \left(-1\right)\right)} - \sin \varepsilon \cdot \sin x \]
      11. metadata-eval98.7%

        \[\leadsto \cos x \cdot \left(\cos \varepsilon + \color{blue}{-1}\right) - \sin \varepsilon \cdot \sin x \]
      12. +-commutative98.7%

        \[\leadsto \cos x \cdot \color{blue}{\left(-1 + \cos \varepsilon\right)} - \sin \varepsilon \cdot \sin x \]
      13. *-commutative98.7%

        \[\leadsto \cos x \cdot \left(-1 + \cos \varepsilon\right) - \color{blue}{\sin x \cdot \sin \varepsilon} \]
    7. Simplified98.7%

      \[\leadsto \color{blue}{\cos x \cdot \left(-1 + \cos \varepsilon\right) - \sin x \cdot \sin \varepsilon} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -2.05 \cdot 10^{-14}:\\ \;\;\;\;\mathsf{fma}\left(-1 + \cos \varepsilon, \cos x, \sin \varepsilon \cdot \left(-\sin x\right)\right)\\ \mathbf{elif}\;x \leq 1.6 \cdot 10^{-34}:\\ \;\;\;\;\left(\sin \left(\left(\varepsilon + \left(x - x\right)\right) \cdot 0.5\right) \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)\right) \cdot -2\\ \mathbf{else}:\\ \;\;\;\;\cos x \cdot \left(-1 + \cos \varepsilon\right) - \sin \varepsilon \cdot \sin x\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 99.1% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.25 \cdot 10^{-16} \lor \neg \left(x \leq 1.6 \cdot 10^{-31}\right):\\ \;\;\;\;\cos x \cdot \left(-1 + \cos \varepsilon\right) - \sin \varepsilon \cdot \sin x\\ \mathbf{else}:\\ \;\;\;\;\left(\sin \left(\left(\varepsilon + \left(x - x\right)\right) \cdot 0.5\right) \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)\right) \cdot -2\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (or (<= x -1.25e-16) (not (<= x 1.6e-31)))
   (- (* (cos x) (+ -1.0 (cos eps))) (* (sin eps) (sin x)))
   (* (* (sin (* (+ eps (- x x)) 0.5)) (sin (* 0.5 (+ eps (+ x x))))) -2.0)))
double code(double x, double eps) {
	double tmp;
	if ((x <= -1.25e-16) || !(x <= 1.6e-31)) {
		tmp = (cos(x) * (-1.0 + cos(eps))) - (sin(eps) * sin(x));
	} else {
		tmp = (sin(((eps + (x - x)) * 0.5)) * sin((0.5 * (eps + (x + x))))) * -2.0;
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if ((x <= (-1.25d-16)) .or. (.not. (x <= 1.6d-31))) then
        tmp = (cos(x) * ((-1.0d0) + cos(eps))) - (sin(eps) * sin(x))
    else
        tmp = (sin(((eps + (x - x)) * 0.5d0)) * sin((0.5d0 * (eps + (x + x))))) * (-2.0d0)
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if ((x <= -1.25e-16) || !(x <= 1.6e-31)) {
		tmp = (Math.cos(x) * (-1.0 + Math.cos(eps))) - (Math.sin(eps) * Math.sin(x));
	} else {
		tmp = (Math.sin(((eps + (x - x)) * 0.5)) * Math.sin((0.5 * (eps + (x + x))))) * -2.0;
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if (x <= -1.25e-16) or not (x <= 1.6e-31):
		tmp = (math.cos(x) * (-1.0 + math.cos(eps))) - (math.sin(eps) * math.sin(x))
	else:
		tmp = (math.sin(((eps + (x - x)) * 0.5)) * math.sin((0.5 * (eps + (x + x))))) * -2.0
	return tmp
function code(x, eps)
	tmp = 0.0
	if ((x <= -1.25e-16) || !(x <= 1.6e-31))
		tmp = Float64(Float64(cos(x) * Float64(-1.0 + cos(eps))) - Float64(sin(eps) * sin(x)));
	else
		tmp = Float64(Float64(sin(Float64(Float64(eps + Float64(x - x)) * 0.5)) * sin(Float64(0.5 * Float64(eps + Float64(x + x))))) * -2.0);
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if ((x <= -1.25e-16) || ~((x <= 1.6e-31)))
		tmp = (cos(x) * (-1.0 + cos(eps))) - (sin(eps) * sin(x));
	else
		tmp = (sin(((eps + (x - x)) * 0.5)) * sin((0.5 * (eps + (x + x))))) * -2.0;
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[Or[LessEqual[x, -1.25e-16], N[Not[LessEqual[x, 1.6e-31]], $MachinePrecision]], N[(N[(N[Cos[x], $MachinePrecision] * N[(-1.0 + N[Cos[eps], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(N[Sin[eps], $MachinePrecision] * N[Sin[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[Sin[N[(N[(eps + N[(x - x), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision]], $MachinePrecision] * N[Sin[N[(0.5 * N[(eps + N[(x + x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * -2.0), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.25 \cdot 10^{-16} \lor \neg \left(x \leq 1.6 \cdot 10^{-31}\right):\\
\;\;\;\;\cos x \cdot \left(-1 + \cos \varepsilon\right) - \sin \varepsilon \cdot \sin x\\

\mathbf{else}:\\
\;\;\;\;\left(\sin \left(\left(\varepsilon + \left(x - x\right)\right) \cdot 0.5\right) \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)\right) \cdot -2\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.2500000000000001e-16 or 1.60000000000000009e-31 < x

    1. Initial program 10.1%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. cos-sum51.8%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \]
      2. cancel-sign-sub-inv51.8%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
      3. fma-def51.8%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    4. Applied egg-rr51.8%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    5. Taylor expanded in x around inf 51.8%

      \[\leadsto \color{blue}{\left(-1 \cdot \left(\sin \varepsilon \cdot \sin x\right) + \cos \varepsilon \cdot \cos x\right) - \cos x} \]
    6. Step-by-step derivation
      1. neg-mul-151.8%

        \[\leadsto \left(\color{blue}{\left(-\sin \varepsilon \cdot \sin x\right)} + \cos \varepsilon \cdot \cos x\right) - \cos x \]
      2. +-commutative51.8%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + \left(-\sin \varepsilon \cdot \sin x\right)\right)} - \cos x \]
      3. sub-neg51.8%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x - \sin \varepsilon \cdot \sin x\right)} - \cos x \]
      4. *-commutative51.8%

        \[\leadsto \left(\color{blue}{\cos x \cdot \cos \varepsilon} - \sin \varepsilon \cdot \sin x\right) - \cos x \]
      5. associate--r+51.8%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \sin x + \cos x\right)} \]
      6. +-commutative51.8%

        \[\leadsto \cos x \cdot \cos \varepsilon - \color{blue}{\left(\cos x + \sin \varepsilon \cdot \sin x\right)} \]
      7. associate--r+99.2%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \cos x\right) - \sin \varepsilon \cdot \sin x} \]
      8. *-rgt-identity99.2%

        \[\leadsto \left(\cos x \cdot \cos \varepsilon - \color{blue}{\cos x \cdot 1}\right) - \sin \varepsilon \cdot \sin x \]
      9. distribute-lft-out--99.1%

        \[\leadsto \color{blue}{\cos x \cdot \left(\cos \varepsilon - 1\right)} - \sin \varepsilon \cdot \sin x \]
      10. sub-neg99.1%

        \[\leadsto \cos x \cdot \color{blue}{\left(\cos \varepsilon + \left(-1\right)\right)} - \sin \varepsilon \cdot \sin x \]
      11. metadata-eval99.1%

        \[\leadsto \cos x \cdot \left(\cos \varepsilon + \color{blue}{-1}\right) - \sin \varepsilon \cdot \sin x \]
      12. +-commutative99.1%

        \[\leadsto \cos x \cdot \color{blue}{\left(-1 + \cos \varepsilon\right)} - \sin \varepsilon \cdot \sin x \]
      13. *-commutative99.1%

        \[\leadsto \cos x \cdot \left(-1 + \cos \varepsilon\right) - \color{blue}{\sin x \cdot \sin \varepsilon} \]
    7. Simplified99.1%

      \[\leadsto \color{blue}{\cos x \cdot \left(-1 + \cos \varepsilon\right) - \sin x \cdot \sin \varepsilon} \]

    if -1.2500000000000001e-16 < x < 1.60000000000000009e-31

    1. Initial program 77.0%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. cos-sum77.0%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \]
      2. cancel-sign-sub-inv77.0%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
      3. fma-def77.0%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    4. Applied egg-rr77.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    5. Taylor expanded in x around inf 77.0%

      \[\leadsto \color{blue}{\left(-1 \cdot \left(\sin \varepsilon \cdot \sin x\right) + \cos \varepsilon \cdot \cos x\right) - \cos x} \]
    6. Step-by-step derivation
      1. neg-mul-177.0%

        \[\leadsto \left(\color{blue}{\left(-\sin \varepsilon \cdot \sin x\right)} + \cos \varepsilon \cdot \cos x\right) - \cos x \]
      2. +-commutative77.0%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + \left(-\sin \varepsilon \cdot \sin x\right)\right)} - \cos x \]
      3. sub-neg77.0%

        \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x - \sin \varepsilon \cdot \sin x\right)} - \cos x \]
      4. *-commutative77.0%

        \[\leadsto \left(\color{blue}{\cos x \cdot \cos \varepsilon} - \sin \varepsilon \cdot \sin x\right) - \cos x \]
      5. associate--r+77.0%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \sin x + \cos x\right)} \]
      6. +-commutative77.0%

        \[\leadsto \cos x \cdot \cos \varepsilon - \color{blue}{\left(\cos x + \sin \varepsilon \cdot \sin x\right)} \]
      7. associate--r+81.7%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \cos x\right) - \sin \varepsilon \cdot \sin x} \]
      8. *-rgt-identity81.7%

        \[\leadsto \left(\cos x \cdot \cos \varepsilon - \color{blue}{\cos x \cdot 1}\right) - \sin \varepsilon \cdot \sin x \]
      9. distribute-lft-out--81.7%

        \[\leadsto \color{blue}{\cos x \cdot \left(\cos \varepsilon - 1\right)} - \sin \varepsilon \cdot \sin x \]
      10. sub-neg81.7%

        \[\leadsto \cos x \cdot \color{blue}{\left(\cos \varepsilon + \left(-1\right)\right)} - \sin \varepsilon \cdot \sin x \]
      11. metadata-eval81.7%

        \[\leadsto \cos x \cdot \left(\cos \varepsilon + \color{blue}{-1}\right) - \sin \varepsilon \cdot \sin x \]
      12. +-commutative81.7%

        \[\leadsto \cos x \cdot \color{blue}{\left(-1 + \cos \varepsilon\right)} - \sin \varepsilon \cdot \sin x \]
      13. *-commutative81.7%

        \[\leadsto \cos x \cdot \left(-1 + \cos \varepsilon\right) - \color{blue}{\sin x \cdot \sin \varepsilon} \]
    7. Simplified81.7%

      \[\leadsto \color{blue}{\cos x \cdot \left(-1 + \cos \varepsilon\right) - \sin x \cdot \sin \varepsilon} \]
    8. Step-by-step derivation
      1. distribute-lft-in81.7%

        \[\leadsto \color{blue}{\left(\cos x \cdot -1 + \cos x \cdot \cos \varepsilon\right)} - \sin x \cdot \sin \varepsilon \]
      2. associate--l+77.0%

        \[\leadsto \color{blue}{\cos x \cdot -1 + \left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} \]
      3. *-commutative77.0%

        \[\leadsto \color{blue}{-1 \cdot \cos x} + \left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right) \]
      4. neg-mul-177.0%

        \[\leadsto \color{blue}{\left(-\cos x\right)} + \left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right) \]
      5. cos-sum77.0%

        \[\leadsto \left(-\cos x\right) + \color{blue}{\cos \left(x + \varepsilon\right)} \]
      6. +-commutative77.0%

        \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) + \left(-\cos x\right)} \]
      7. sub-neg77.0%

        \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) - \cos x} \]
      8. diff-cos94.9%

        \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      9. *-commutative94.9%

        \[\leadsto \color{blue}{\left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \cdot -2} \]
    9. Applied egg-rr99.6%

      \[\leadsto \color{blue}{\left(\sin \left(\left(\varepsilon + \left(x - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right) \cdot -2} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.25 \cdot 10^{-16} \lor \neg \left(x \leq 1.6 \cdot 10^{-31}\right):\\ \;\;\;\;\cos x \cdot \left(-1 + \cos \varepsilon\right) - \sin \varepsilon \cdot \sin x\\ \mathbf{else}:\\ \;\;\;\;\left(\sin \left(\left(\varepsilon + \left(x - x\right)\right) \cdot 0.5\right) \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)\right) \cdot -2\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 71.5% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sin \left(\varepsilon \cdot 0.5\right)\\ t_1 := \sin x \cdot \left(-2 \cdot t_0\right)\\ \mathbf{if}\;x \leq -5.2 \cdot 10^{-18}:\\ \;\;\;\;t_1\\ \mathbf{elif}\;x \leq 1.76 \cdot 10^{-124}:\\ \;\;\;\;-2 \cdot {t_0}^{2}\\ \mathbf{elif}\;x \leq 0.0028:\\ \;\;\;\;\left(-1 + \cos \varepsilon\right) - \sin \varepsilon \cdot x\\ \mathbf{else}:\\ \;\;\;\;t_1\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (sin (* eps 0.5))) (t_1 (* (sin x) (* -2.0 t_0))))
   (if (<= x -5.2e-18)
     t_1
     (if (<= x 1.76e-124)
       (* -2.0 (pow t_0 2.0))
       (if (<= x 0.0028) (- (+ -1.0 (cos eps)) (* (sin eps) x)) t_1)))))
double code(double x, double eps) {
	double t_0 = sin((eps * 0.5));
	double t_1 = sin(x) * (-2.0 * t_0);
	double tmp;
	if (x <= -5.2e-18) {
		tmp = t_1;
	} else if (x <= 1.76e-124) {
		tmp = -2.0 * pow(t_0, 2.0);
	} else if (x <= 0.0028) {
		tmp = (-1.0 + cos(eps)) - (sin(eps) * x);
	} else {
		tmp = t_1;
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = sin((eps * 0.5d0))
    t_1 = sin(x) * ((-2.0d0) * t_0)
    if (x <= (-5.2d-18)) then
        tmp = t_1
    else if (x <= 1.76d-124) then
        tmp = (-2.0d0) * (t_0 ** 2.0d0)
    else if (x <= 0.0028d0) then
        tmp = ((-1.0d0) + cos(eps)) - (sin(eps) * x)
    else
        tmp = t_1
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double t_0 = Math.sin((eps * 0.5));
	double t_1 = Math.sin(x) * (-2.0 * t_0);
	double tmp;
	if (x <= -5.2e-18) {
		tmp = t_1;
	} else if (x <= 1.76e-124) {
		tmp = -2.0 * Math.pow(t_0, 2.0);
	} else if (x <= 0.0028) {
		tmp = (-1.0 + Math.cos(eps)) - (Math.sin(eps) * x);
	} else {
		tmp = t_1;
	}
	return tmp;
}
def code(x, eps):
	t_0 = math.sin((eps * 0.5))
	t_1 = math.sin(x) * (-2.0 * t_0)
	tmp = 0
	if x <= -5.2e-18:
		tmp = t_1
	elif x <= 1.76e-124:
		tmp = -2.0 * math.pow(t_0, 2.0)
	elif x <= 0.0028:
		tmp = (-1.0 + math.cos(eps)) - (math.sin(eps) * x)
	else:
		tmp = t_1
	return tmp
function code(x, eps)
	t_0 = sin(Float64(eps * 0.5))
	t_1 = Float64(sin(x) * Float64(-2.0 * t_0))
	tmp = 0.0
	if (x <= -5.2e-18)
		tmp = t_1;
	elseif (x <= 1.76e-124)
		tmp = Float64(-2.0 * (t_0 ^ 2.0));
	elseif (x <= 0.0028)
		tmp = Float64(Float64(-1.0 + cos(eps)) - Float64(sin(eps) * x));
	else
		tmp = t_1;
	end
	return tmp
end
function tmp_2 = code(x, eps)
	t_0 = sin((eps * 0.5));
	t_1 = sin(x) * (-2.0 * t_0);
	tmp = 0.0;
	if (x <= -5.2e-18)
		tmp = t_1;
	elseif (x <= 1.76e-124)
		tmp = -2.0 * (t_0 ^ 2.0);
	elseif (x <= 0.0028)
		tmp = (-1.0 + cos(eps)) - (sin(eps) * x);
	else
		tmp = t_1;
	end
	tmp_2 = tmp;
end
code[x_, eps_] := Block[{t$95$0 = N[Sin[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[Sin[x], $MachinePrecision] * N[(-2.0 * t$95$0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[x, -5.2e-18], t$95$1, If[LessEqual[x, 1.76e-124], N[(-2.0 * N[Power[t$95$0, 2.0], $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 0.0028], N[(N[(-1.0 + N[Cos[eps], $MachinePrecision]), $MachinePrecision] - N[(N[Sin[eps], $MachinePrecision] * x), $MachinePrecision]), $MachinePrecision], t$95$1]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sin \left(\varepsilon \cdot 0.5\right)\\
t_1 := \sin x \cdot \left(-2 \cdot t_0\right)\\
\mathbf{if}\;x \leq -5.2 \cdot 10^{-18}:\\
\;\;\;\;t_1\\

\mathbf{elif}\;x \leq 1.76 \cdot 10^{-124}:\\
\;\;\;\;-2 \cdot {t_0}^{2}\\

\mathbf{elif}\;x \leq 0.0028:\\
\;\;\;\;\left(-1 + \cos \varepsilon\right) - \sin \varepsilon \cdot x\\

\mathbf{else}:\\
\;\;\;\;t_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -5.2000000000000001e-18 or 0.00279999999999999997 < x

    1. Initial program 9.1%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. diff-cos7.5%

        \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      2. div-inv7.5%

        \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      3. associate--l+7.5%

        \[\leadsto -2 \cdot \left(\sin \left(\color{blue}{\left(x + \left(\varepsilon - x\right)\right)} \cdot \frac{1}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      4. metadata-eval7.5%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      5. div-inv7.5%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
      6. +-commutative7.5%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\color{blue}{\left(\varepsilon + x\right)} + x\right) \cdot \frac{1}{2}\right)\right) \]
      7. associate-+l+7.6%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(\varepsilon + \left(x + x\right)\right)} \cdot \frac{1}{2}\right)\right) \]
      8. metadata-eval7.6%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
    4. Applied egg-rr7.6%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right)} \]
    5. Step-by-step derivation
      1. associate-*r*7.6%

        \[\leadsto \color{blue}{\left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)} \]
      2. *-commutative7.6%

        \[\leadsto \color{blue}{\sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right)} \]
      3. *-commutative7.6%

        \[\leadsto \sin \color{blue}{\left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)} \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      4. +-commutative7.6%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      5. count-27.6%

        \[\leadsto \sin \left(0.5 \cdot \left(\color{blue}{2 \cdot x} + \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      6. fma-def7.6%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\mathsf{fma}\left(2, x, \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      7. sub-neg7.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(\varepsilon + \left(-x\right)\right)}\right) \cdot 0.5\right)\right) \]
      8. mul-1-neg7.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon + \color{blue}{-1 \cdot x}\right)\right) \cdot 0.5\right)\right) \]
      9. +-commutative7.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(-1 \cdot x + \varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      10. associate-+r+57.3%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(\left(x + -1 \cdot x\right) + \varepsilon\right)} \cdot 0.5\right)\right) \]
      11. mul-1-neg57.3%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\left(x + \color{blue}{\left(-x\right)}\right) + \varepsilon\right) \cdot 0.5\right)\right) \]
      12. sub-neg57.3%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{\left(x - x\right)} + \varepsilon\right) \cdot 0.5\right)\right) \]
      13. +-inverses57.3%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{0} + \varepsilon\right) \cdot 0.5\right)\right) \]
      14. remove-double-neg57.3%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \color{blue}{\left(-\left(-\varepsilon\right)\right)}\right) \cdot 0.5\right)\right) \]
      15. mul-1-neg57.3%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \left(-\color{blue}{-1 \cdot \varepsilon}\right)\right) \cdot 0.5\right)\right) \]
      16. sub-neg57.3%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(0 - -1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      17. neg-sub057.3%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(--1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      18. mul-1-neg57.3%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(-\color{blue}{\left(-\varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      19. remove-double-neg57.3%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\varepsilon} \cdot 0.5\right)\right) \]
    6. Simplified57.3%

      \[\leadsto \color{blue}{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)} \]
    7. Taylor expanded in eps around 0 56.5%

      \[\leadsto \color{blue}{\sin x} \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]

    if -5.2000000000000001e-18 < x < 1.75999999999999996e-124

    1. Initial program 79.3%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. diff-cos99.2%

        \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      2. div-inv99.2%

        \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      3. associate--l+99.2%

        \[\leadsto -2 \cdot \left(\sin \left(\color{blue}{\left(x + \left(\varepsilon - x\right)\right)} \cdot \frac{1}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      4. metadata-eval99.2%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      5. div-inv99.2%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
      6. +-commutative99.2%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\color{blue}{\left(\varepsilon + x\right)} + x\right) \cdot \frac{1}{2}\right)\right) \]
      7. associate-+l+99.2%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(\varepsilon + \left(x + x\right)\right)} \cdot \frac{1}{2}\right)\right) \]
      8. metadata-eval99.2%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
    4. Applied egg-rr99.2%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right)} \]
    5. Step-by-step derivation
      1. associate-*r*99.2%

        \[\leadsto \color{blue}{\left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)} \]
      2. *-commutative99.2%

        \[\leadsto \color{blue}{\sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right)} \]
      3. *-commutative99.2%

        \[\leadsto \sin \color{blue}{\left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)} \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      4. +-commutative99.2%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      5. count-299.2%

        \[\leadsto \sin \left(0.5 \cdot \left(\color{blue}{2 \cdot x} + \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      6. fma-def99.2%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\mathsf{fma}\left(2, x, \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      7. sub-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(\varepsilon + \left(-x\right)\right)}\right) \cdot 0.5\right)\right) \]
      8. mul-1-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon + \color{blue}{-1 \cdot x}\right)\right) \cdot 0.5\right)\right) \]
      9. +-commutative99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(-1 \cdot x + \varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      10. associate-+r+99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(\left(x + -1 \cdot x\right) + \varepsilon\right)} \cdot 0.5\right)\right) \]
      11. mul-1-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\left(x + \color{blue}{\left(-x\right)}\right) + \varepsilon\right) \cdot 0.5\right)\right) \]
      12. sub-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{\left(x - x\right)} + \varepsilon\right) \cdot 0.5\right)\right) \]
      13. +-inverses99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{0} + \varepsilon\right) \cdot 0.5\right)\right) \]
      14. remove-double-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \color{blue}{\left(-\left(-\varepsilon\right)\right)}\right) \cdot 0.5\right)\right) \]
      15. mul-1-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \left(-\color{blue}{-1 \cdot \varepsilon}\right)\right) \cdot 0.5\right)\right) \]
      16. sub-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(0 - -1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      17. neg-sub099.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(--1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      18. mul-1-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(-\color{blue}{\left(-\varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      19. remove-double-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\varepsilon} \cdot 0.5\right)\right) \]
    6. Simplified99.6%

      \[\leadsto \color{blue}{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)} \]
    7. Taylor expanded in x around 0 98.5%

      \[\leadsto \color{blue}{-2 \cdot {\sin \left(0.5 \cdot \varepsilon\right)}^{2}} \]

    if 1.75999999999999996e-124 < x < 0.00279999999999999997

    1. Initial program 59.2%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 62.1%

      \[\leadsto \color{blue}{\left(\cos \varepsilon + \left(-1 \cdot \left(x \cdot \sin \varepsilon\right) + {x}^{2} \cdot \left(0.5 + -0.5 \cdot \cos \varepsilon\right)\right)\right) - 1} \]
    4. Step-by-step derivation
      1. sub-neg62.1%

        \[\leadsto \color{blue}{\left(\cos \varepsilon + \left(-1 \cdot \left(x \cdot \sin \varepsilon\right) + {x}^{2} \cdot \left(0.5 + -0.5 \cdot \cos \varepsilon\right)\right)\right) + \left(-1\right)} \]
      2. metadata-eval62.1%

        \[\leadsto \left(\cos \varepsilon + \left(-1 \cdot \left(x \cdot \sin \varepsilon\right) + {x}^{2} \cdot \left(0.5 + -0.5 \cdot \cos \varepsilon\right)\right)\right) + \color{blue}{-1} \]
      3. +-commutative62.1%

        \[\leadsto \color{blue}{-1 + \left(\cos \varepsilon + \left(-1 \cdot \left(x \cdot \sin \varepsilon\right) + {x}^{2} \cdot \left(0.5 + -0.5 \cdot \cos \varepsilon\right)\right)\right)} \]
      4. associate-+r+91.2%

        \[\leadsto \color{blue}{\left(-1 + \cos \varepsilon\right) + \left(-1 \cdot \left(x \cdot \sin \varepsilon\right) + {x}^{2} \cdot \left(0.5 + -0.5 \cdot \cos \varepsilon\right)\right)} \]
      5. +-commutative91.2%

        \[\leadsto \color{blue}{\left(\cos \varepsilon + -1\right)} + \left(-1 \cdot \left(x \cdot \sin \varepsilon\right) + {x}^{2} \cdot \left(0.5 + -0.5 \cdot \cos \varepsilon\right)\right) \]
      6. +-commutative91.2%

        \[\leadsto \left(\cos \varepsilon + -1\right) + \color{blue}{\left({x}^{2} \cdot \left(0.5 + -0.5 \cdot \cos \varepsilon\right) + -1 \cdot \left(x \cdot \sin \varepsilon\right)\right)} \]
      7. mul-1-neg91.2%

        \[\leadsto \left(\cos \varepsilon + -1\right) + \left({x}^{2} \cdot \left(0.5 + -0.5 \cdot \cos \varepsilon\right) + \color{blue}{\left(-x \cdot \sin \varepsilon\right)}\right) \]
      8. unsub-neg91.2%

        \[\leadsto \left(\cos \varepsilon + -1\right) + \color{blue}{\left({x}^{2} \cdot \left(0.5 + -0.5 \cdot \cos \varepsilon\right) - x \cdot \sin \varepsilon\right)} \]
      9. unpow291.2%

        \[\leadsto \left(\cos \varepsilon + -1\right) + \left(\color{blue}{\left(x \cdot x\right)} \cdot \left(0.5 + -0.5 \cdot \cos \varepsilon\right) - x \cdot \sin \varepsilon\right) \]
      10. associate-*l*91.2%

        \[\leadsto \left(\cos \varepsilon + -1\right) + \left(\color{blue}{x \cdot \left(x \cdot \left(0.5 + -0.5 \cdot \cos \varepsilon\right)\right)} - x \cdot \sin \varepsilon\right) \]
      11. distribute-lft-out--91.2%

        \[\leadsto \left(\cos \varepsilon + -1\right) + \color{blue}{x \cdot \left(x \cdot \left(0.5 + -0.5 \cdot \cos \varepsilon\right) - \sin \varepsilon\right)} \]
      12. +-commutative91.2%

        \[\leadsto \left(\cos \varepsilon + -1\right) + x \cdot \left(x \cdot \color{blue}{\left(-0.5 \cdot \cos \varepsilon + 0.5\right)} - \sin \varepsilon\right) \]
      13. *-commutative91.2%

        \[\leadsto \left(\cos \varepsilon + -1\right) + x \cdot \left(x \cdot \left(\color{blue}{\cos \varepsilon \cdot -0.5} + 0.5\right) - \sin \varepsilon\right) \]
      14. fma-def91.2%

        \[\leadsto \left(\cos \varepsilon + -1\right) + x \cdot \left(x \cdot \color{blue}{\mathsf{fma}\left(\cos \varepsilon, -0.5, 0.5\right)} - \sin \varepsilon\right) \]
    5. Simplified91.2%

      \[\leadsto \color{blue}{\left(\cos \varepsilon + -1\right) + x \cdot \left(x \cdot \mathsf{fma}\left(\cos \varepsilon, -0.5, 0.5\right) - \sin \varepsilon\right)} \]
    6. Taylor expanded in x around 0 90.1%

      \[\leadsto \left(\cos \varepsilon + -1\right) + \color{blue}{-1 \cdot \left(x \cdot \sin \varepsilon\right)} \]
    7. Step-by-step derivation
      1. mul-1-neg90.1%

        \[\leadsto \left(\cos \varepsilon + -1\right) + \color{blue}{\left(-x \cdot \sin \varepsilon\right)} \]
      2. distribute-rgt-neg-out90.1%

        \[\leadsto \left(\cos \varepsilon + -1\right) + \color{blue}{x \cdot \left(-\sin \varepsilon\right)} \]
    8. Simplified90.1%

      \[\leadsto \left(\cos \varepsilon + -1\right) + \color{blue}{x \cdot \left(-\sin \varepsilon\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification75.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -5.2 \cdot 10^{-18}:\\ \;\;\;\;\sin x \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)\\ \mathbf{elif}\;x \leq 1.76 \cdot 10^{-124}:\\ \;\;\;\;-2 \cdot {\sin \left(\varepsilon \cdot 0.5\right)}^{2}\\ \mathbf{elif}\;x \leq 0.0028:\\ \;\;\;\;\left(-1 + \cos \varepsilon\right) - \sin \varepsilon \cdot x\\ \mathbf{else}:\\ \;\;\;\;\sin x \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 8: 67.6% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos \varepsilon - \cos x\\ \mathbf{if}\;\varepsilon \leq -2.9 \cdot 10^{-5}:\\ \;\;\;\;t_0\\ \mathbf{elif}\;\varepsilon \leq 4.6 \cdot 10^{-17}:\\ \;\;\;\;\sin x \cdot \left(-\varepsilon\right)\\ \mathbf{elif}\;\varepsilon \leq 0.00014:\\ \;\;\;\;-0.5 \cdot {\varepsilon}^{2}\\ \mathbf{else}:\\ \;\;\;\;t_0\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (- (cos eps) (cos x))))
   (if (<= eps -2.9e-5)
     t_0
     (if (<= eps 4.6e-17)
       (* (sin x) (- eps))
       (if (<= eps 0.00014) (* -0.5 (pow eps 2.0)) t_0)))))
double code(double x, double eps) {
	double t_0 = cos(eps) - cos(x);
	double tmp;
	if (eps <= -2.9e-5) {
		tmp = t_0;
	} else if (eps <= 4.6e-17) {
		tmp = sin(x) * -eps;
	} else if (eps <= 0.00014) {
		tmp = -0.5 * pow(eps, 2.0);
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: t_0
    real(8) :: tmp
    t_0 = cos(eps) - cos(x)
    if (eps <= (-2.9d-5)) then
        tmp = t_0
    else if (eps <= 4.6d-17) then
        tmp = sin(x) * -eps
    else if (eps <= 0.00014d0) then
        tmp = (-0.5d0) * (eps ** 2.0d0)
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double t_0 = Math.cos(eps) - Math.cos(x);
	double tmp;
	if (eps <= -2.9e-5) {
		tmp = t_0;
	} else if (eps <= 4.6e-17) {
		tmp = Math.sin(x) * -eps;
	} else if (eps <= 0.00014) {
		tmp = -0.5 * Math.pow(eps, 2.0);
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x, eps):
	t_0 = math.cos(eps) - math.cos(x)
	tmp = 0
	if eps <= -2.9e-5:
		tmp = t_0
	elif eps <= 4.6e-17:
		tmp = math.sin(x) * -eps
	elif eps <= 0.00014:
		tmp = -0.5 * math.pow(eps, 2.0)
	else:
		tmp = t_0
	return tmp
function code(x, eps)
	t_0 = Float64(cos(eps) - cos(x))
	tmp = 0.0
	if (eps <= -2.9e-5)
		tmp = t_0;
	elseif (eps <= 4.6e-17)
		tmp = Float64(sin(x) * Float64(-eps));
	elseif (eps <= 0.00014)
		tmp = Float64(-0.5 * (eps ^ 2.0));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x, eps)
	t_0 = cos(eps) - cos(x);
	tmp = 0.0;
	if (eps <= -2.9e-5)
		tmp = t_0;
	elseif (eps <= 4.6e-17)
		tmp = sin(x) * -eps;
	elseif (eps <= 0.00014)
		tmp = -0.5 * (eps ^ 2.0);
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_, eps_] := Block[{t$95$0 = N[(N[Cos[eps], $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[eps, -2.9e-5], t$95$0, If[LessEqual[eps, 4.6e-17], N[(N[Sin[x], $MachinePrecision] * (-eps)), $MachinePrecision], If[LessEqual[eps, 0.00014], N[(-0.5 * N[Power[eps, 2.0], $MachinePrecision]), $MachinePrecision], t$95$0]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos \varepsilon - \cos x\\
\mathbf{if}\;\varepsilon \leq -2.9 \cdot 10^{-5}:\\
\;\;\;\;t_0\\

\mathbf{elif}\;\varepsilon \leq 4.6 \cdot 10^{-17}:\\
\;\;\;\;\sin x \cdot \left(-\varepsilon\right)\\

\mathbf{elif}\;\varepsilon \leq 0.00014:\\
\;\;\;\;-0.5 \cdot {\varepsilon}^{2}\\

\mathbf{else}:\\
\;\;\;\;t_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if eps < -2.9e-5 or 1.3999999999999999e-4 < eps

    1. Initial program 54.5%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 56.9%

      \[\leadsto \color{blue}{\cos \varepsilon} - \cos x \]

    if -2.9e-5 < eps < 4.60000000000000018e-17

    1. Initial program 25.7%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in eps around 0 86.6%

      \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)} \]
    4. Step-by-step derivation
      1. mul-1-neg86.6%

        \[\leadsto \color{blue}{-\varepsilon \cdot \sin x} \]
      2. *-commutative86.6%

        \[\leadsto -\color{blue}{\sin x \cdot \varepsilon} \]
      3. distribute-rgt-neg-in86.6%

        \[\leadsto \color{blue}{\sin x \cdot \left(-\varepsilon\right)} \]
    5. Simplified86.6%

      \[\leadsto \color{blue}{\sin x \cdot \left(-\varepsilon\right)} \]

    if 4.60000000000000018e-17 < eps < 1.3999999999999999e-4

    1. Initial program 13.0%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 13.0%

      \[\leadsto \color{blue}{\cos \varepsilon - 1} \]
    4. Taylor expanded in eps around 0 97.5%

      \[\leadsto \color{blue}{-0.5 \cdot {\varepsilon}^{2}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification71.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -2.9 \cdot 10^{-5}:\\ \;\;\;\;\cos \varepsilon - \cos x\\ \mathbf{elif}\;\varepsilon \leq 4.6 \cdot 10^{-17}:\\ \;\;\;\;\sin x \cdot \left(-\varepsilon\right)\\ \mathbf{elif}\;\varepsilon \leq 0.00014:\\ \;\;\;\;-0.5 \cdot {\varepsilon}^{2}\\ \mathbf{else}:\\ \;\;\;\;\cos \varepsilon - \cos x\\ \end{array} \]
  5. Add Preprocessing

Alternative 9: 69.5% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sin \left(\varepsilon \cdot 0.5\right)\\ \mathbf{if}\;x \leq -3 \cdot 10^{-20} \lor \neg \left(x \leq 6 \cdot 10^{-31}\right):\\ \;\;\;\;\sin x \cdot \left(-2 \cdot t_0\right)\\ \mathbf{else}:\\ \;\;\;\;-2 \cdot {t_0}^{2}\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (sin (* eps 0.5))))
   (if (or (<= x -3e-20) (not (<= x 6e-31)))
     (* (sin x) (* -2.0 t_0))
     (* -2.0 (pow t_0 2.0)))))
double code(double x, double eps) {
	double t_0 = sin((eps * 0.5));
	double tmp;
	if ((x <= -3e-20) || !(x <= 6e-31)) {
		tmp = sin(x) * (-2.0 * t_0);
	} else {
		tmp = -2.0 * pow(t_0, 2.0);
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: t_0
    real(8) :: tmp
    t_0 = sin((eps * 0.5d0))
    if ((x <= (-3d-20)) .or. (.not. (x <= 6d-31))) then
        tmp = sin(x) * ((-2.0d0) * t_0)
    else
        tmp = (-2.0d0) * (t_0 ** 2.0d0)
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double t_0 = Math.sin((eps * 0.5));
	double tmp;
	if ((x <= -3e-20) || !(x <= 6e-31)) {
		tmp = Math.sin(x) * (-2.0 * t_0);
	} else {
		tmp = -2.0 * Math.pow(t_0, 2.0);
	}
	return tmp;
}
def code(x, eps):
	t_0 = math.sin((eps * 0.5))
	tmp = 0
	if (x <= -3e-20) or not (x <= 6e-31):
		tmp = math.sin(x) * (-2.0 * t_0)
	else:
		tmp = -2.0 * math.pow(t_0, 2.0)
	return tmp
function code(x, eps)
	t_0 = sin(Float64(eps * 0.5))
	tmp = 0.0
	if ((x <= -3e-20) || !(x <= 6e-31))
		tmp = Float64(sin(x) * Float64(-2.0 * t_0));
	else
		tmp = Float64(-2.0 * (t_0 ^ 2.0));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	t_0 = sin((eps * 0.5));
	tmp = 0.0;
	if ((x <= -3e-20) || ~((x <= 6e-31)))
		tmp = sin(x) * (-2.0 * t_0);
	else
		tmp = -2.0 * (t_0 ^ 2.0);
	end
	tmp_2 = tmp;
end
code[x_, eps_] := Block[{t$95$0 = N[Sin[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision]}, If[Or[LessEqual[x, -3e-20], N[Not[LessEqual[x, 6e-31]], $MachinePrecision]], N[(N[Sin[x], $MachinePrecision] * N[(-2.0 * t$95$0), $MachinePrecision]), $MachinePrecision], N[(-2.0 * N[Power[t$95$0, 2.0], $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sin \left(\varepsilon \cdot 0.5\right)\\
\mathbf{if}\;x \leq -3 \cdot 10^{-20} \lor \neg \left(x \leq 6 \cdot 10^{-31}\right):\\
\;\;\;\;\sin x \cdot \left(-2 \cdot t_0\right)\\

\mathbf{else}:\\
\;\;\;\;-2 \cdot {t_0}^{2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -3.00000000000000029e-20 or 5.99999999999999962e-31 < x

    1. Initial program 10.1%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. diff-cos8.6%

        \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      2. div-inv8.6%

        \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      3. associate--l+8.6%

        \[\leadsto -2 \cdot \left(\sin \left(\color{blue}{\left(x + \left(\varepsilon - x\right)\right)} \cdot \frac{1}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      4. metadata-eval8.6%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      5. div-inv8.6%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
      6. +-commutative8.6%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\color{blue}{\left(\varepsilon + x\right)} + x\right) \cdot \frac{1}{2}\right)\right) \]
      7. associate-+l+8.7%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(\varepsilon + \left(x + x\right)\right)} \cdot \frac{1}{2}\right)\right) \]
      8. metadata-eval8.7%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
    4. Applied egg-rr8.7%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right)} \]
    5. Step-by-step derivation
      1. associate-*r*8.7%

        \[\leadsto \color{blue}{\left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)} \]
      2. *-commutative8.7%

        \[\leadsto \color{blue}{\sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right)} \]
      3. *-commutative8.7%

        \[\leadsto \sin \color{blue}{\left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)} \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      4. +-commutative8.7%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      5. count-28.7%

        \[\leadsto \sin \left(0.5 \cdot \left(\color{blue}{2 \cdot x} + \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      6. fma-def8.7%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\mathsf{fma}\left(2, x, \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      7. sub-neg8.7%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(\varepsilon + \left(-x\right)\right)}\right) \cdot 0.5\right)\right) \]
      8. mul-1-neg8.7%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon + \color{blue}{-1 \cdot x}\right)\right) \cdot 0.5\right)\right) \]
      9. +-commutative8.7%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(-1 \cdot x + \varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      10. associate-+r+58.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(\left(x + -1 \cdot x\right) + \varepsilon\right)} \cdot 0.5\right)\right) \]
      11. mul-1-neg58.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\left(x + \color{blue}{\left(-x\right)}\right) + \varepsilon\right) \cdot 0.5\right)\right) \]
      12. sub-neg58.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{\left(x - x\right)} + \varepsilon\right) \cdot 0.5\right)\right) \]
      13. +-inverses58.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{0} + \varepsilon\right) \cdot 0.5\right)\right) \]
      14. remove-double-neg58.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \color{blue}{\left(-\left(-\varepsilon\right)\right)}\right) \cdot 0.5\right)\right) \]
      15. mul-1-neg58.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \left(-\color{blue}{-1 \cdot \varepsilon}\right)\right) \cdot 0.5\right)\right) \]
      16. sub-neg58.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(0 - -1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      17. neg-sub058.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(--1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      18. mul-1-neg58.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(-\color{blue}{\left(-\varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      19. remove-double-neg58.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\varepsilon} \cdot 0.5\right)\right) \]
    6. Simplified58.5%

      \[\leadsto \color{blue}{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)} \]
    7. Taylor expanded in eps around 0 56.7%

      \[\leadsto \color{blue}{\sin x} \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]

    if -3.00000000000000029e-20 < x < 5.99999999999999962e-31

    1. Initial program 77.6%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. diff-cos95.7%

        \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      2. div-inv95.7%

        \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      3. associate--l+95.7%

        \[\leadsto -2 \cdot \left(\sin \left(\color{blue}{\left(x + \left(\varepsilon - x\right)\right)} \cdot \frac{1}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      4. metadata-eval95.7%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      5. div-inv95.7%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
      6. +-commutative95.7%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\color{blue}{\left(\varepsilon + x\right)} + x\right) \cdot \frac{1}{2}\right)\right) \]
      7. associate-+l+95.7%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(\varepsilon + \left(x + x\right)\right)} \cdot \frac{1}{2}\right)\right) \]
      8. metadata-eval95.7%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
    4. Applied egg-rr95.7%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right)} \]
    5. Step-by-step derivation
      1. associate-*r*95.7%

        \[\leadsto \color{blue}{\left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)} \]
      2. *-commutative95.7%

        \[\leadsto \color{blue}{\sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right)} \]
      3. *-commutative95.7%

        \[\leadsto \sin \color{blue}{\left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)} \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      4. +-commutative95.7%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      5. count-295.7%

        \[\leadsto \sin \left(0.5 \cdot \left(\color{blue}{2 \cdot x} + \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      6. fma-def95.7%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\mathsf{fma}\left(2, x, \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      7. sub-neg95.7%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(\varepsilon + \left(-x\right)\right)}\right) \cdot 0.5\right)\right) \]
      8. mul-1-neg95.7%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon + \color{blue}{-1 \cdot x}\right)\right) \cdot 0.5\right)\right) \]
      9. +-commutative95.7%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(-1 \cdot x + \varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      10. associate-+r+99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(\left(x + -1 \cdot x\right) + \varepsilon\right)} \cdot 0.5\right)\right) \]
      11. mul-1-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\left(x + \color{blue}{\left(-x\right)}\right) + \varepsilon\right) \cdot 0.5\right)\right) \]
      12. sub-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{\left(x - x\right)} + \varepsilon\right) \cdot 0.5\right)\right) \]
      13. +-inverses99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{0} + \varepsilon\right) \cdot 0.5\right)\right) \]
      14. remove-double-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \color{blue}{\left(-\left(-\varepsilon\right)\right)}\right) \cdot 0.5\right)\right) \]
      15. mul-1-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \left(-\color{blue}{-1 \cdot \varepsilon}\right)\right) \cdot 0.5\right)\right) \]
      16. sub-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(0 - -1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      17. neg-sub099.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(--1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      18. mul-1-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(-\color{blue}{\left(-\varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      19. remove-double-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\varepsilon} \cdot 0.5\right)\right) \]
    6. Simplified99.6%

      \[\leadsto \color{blue}{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)} \]
    7. Taylor expanded in x around 0 95.2%

      \[\leadsto \color{blue}{-2 \cdot {\sin \left(0.5 \cdot \varepsilon\right)}^{2}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification73.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -3 \cdot 10^{-20} \lor \neg \left(x \leq 6 \cdot 10^{-31}\right):\\ \;\;\;\;\sin x \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)\\ \mathbf{else}:\\ \;\;\;\;-2 \cdot {\sin \left(\varepsilon \cdot 0.5\right)}^{2}\\ \end{array} \]
  5. Add Preprocessing

Alternative 10: 75.5% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \left(\sin \left(\left(\varepsilon + \left(x - x\right)\right) \cdot 0.5\right) \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)\right) \cdot -2 \end{array} \]
(FPCore (x eps)
 :precision binary64
 (* (* (sin (* (+ eps (- x x)) 0.5)) (sin (* 0.5 (+ eps (+ x x))))) -2.0))
double code(double x, double eps) {
	return (sin(((eps + (x - x)) * 0.5)) * sin((0.5 * (eps + (x + x))))) * -2.0;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = (sin(((eps + (x - x)) * 0.5d0)) * sin((0.5d0 * (eps + (x + x))))) * (-2.0d0)
end function
public static double code(double x, double eps) {
	return (Math.sin(((eps + (x - x)) * 0.5)) * Math.sin((0.5 * (eps + (x + x))))) * -2.0;
}
def code(x, eps):
	return (math.sin(((eps + (x - x)) * 0.5)) * math.sin((0.5 * (eps + (x + x))))) * -2.0
function code(x, eps)
	return Float64(Float64(sin(Float64(Float64(eps + Float64(x - x)) * 0.5)) * sin(Float64(0.5 * Float64(eps + Float64(x + x))))) * -2.0)
end
function tmp = code(x, eps)
	tmp = (sin(((eps + (x - x)) * 0.5)) * sin((0.5 * (eps + (x + x))))) * -2.0;
end
code[x_, eps_] := N[(N[(N[Sin[N[(N[(eps + N[(x - x), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision]], $MachinePrecision] * N[Sin[N[(0.5 * N[(eps + N[(x + x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * -2.0), $MachinePrecision]
\begin{array}{l}

\\
\left(\sin \left(\left(\varepsilon + \left(x - x\right)\right) \cdot 0.5\right) \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)\right) \cdot -2
\end{array}
Derivation
  1. Initial program 40.1%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. cos-sum63.1%

      \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \]
    2. cancel-sign-sub-inv63.1%

      \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    3. fma-def63.1%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
  4. Applied egg-rr63.1%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
  5. Taylor expanded in x around inf 63.1%

    \[\leadsto \color{blue}{\left(-1 \cdot \left(\sin \varepsilon \cdot \sin x\right) + \cos \varepsilon \cdot \cos x\right) - \cos x} \]
  6. Step-by-step derivation
    1. neg-mul-163.1%

      \[\leadsto \left(\color{blue}{\left(-\sin \varepsilon \cdot \sin x\right)} + \cos \varepsilon \cdot \cos x\right) - \cos x \]
    2. +-commutative63.1%

      \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x + \left(-\sin \varepsilon \cdot \sin x\right)\right)} - \cos x \]
    3. sub-neg63.1%

      \[\leadsto \color{blue}{\left(\cos \varepsilon \cdot \cos x - \sin \varepsilon \cdot \sin x\right)} - \cos x \]
    4. *-commutative63.1%

      \[\leadsto \left(\color{blue}{\cos x \cdot \cos \varepsilon} - \sin \varepsilon \cdot \sin x\right) - \cos x \]
    5. associate--r+63.1%

      \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin \varepsilon \cdot \sin x + \cos x\right)} \]
    6. +-commutative63.1%

      \[\leadsto \cos x \cdot \cos \varepsilon - \color{blue}{\left(\cos x + \sin \varepsilon \cdot \sin x\right)} \]
    7. associate--r+91.3%

      \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \cos x\right) - \sin \varepsilon \cdot \sin x} \]
    8. *-rgt-identity91.3%

      \[\leadsto \left(\cos x \cdot \cos \varepsilon - \color{blue}{\cos x \cdot 1}\right) - \sin \varepsilon \cdot \sin x \]
    9. distribute-lft-out--91.3%

      \[\leadsto \color{blue}{\cos x \cdot \left(\cos \varepsilon - 1\right)} - \sin \varepsilon \cdot \sin x \]
    10. sub-neg91.3%

      \[\leadsto \cos x \cdot \color{blue}{\left(\cos \varepsilon + \left(-1\right)\right)} - \sin \varepsilon \cdot \sin x \]
    11. metadata-eval91.3%

      \[\leadsto \cos x \cdot \left(\cos \varepsilon + \color{blue}{-1}\right) - \sin \varepsilon \cdot \sin x \]
    12. +-commutative91.3%

      \[\leadsto \cos x \cdot \color{blue}{\left(-1 + \cos \varepsilon\right)} - \sin \varepsilon \cdot \sin x \]
    13. *-commutative91.3%

      \[\leadsto \cos x \cdot \left(-1 + \cos \varepsilon\right) - \color{blue}{\sin x \cdot \sin \varepsilon} \]
  7. Simplified91.3%

    \[\leadsto \color{blue}{\cos x \cdot \left(-1 + \cos \varepsilon\right) - \sin x \cdot \sin \varepsilon} \]
  8. Step-by-step derivation
    1. distribute-lft-in91.3%

      \[\leadsto \color{blue}{\left(\cos x \cdot -1 + \cos x \cdot \cos \varepsilon\right)} - \sin x \cdot \sin \varepsilon \]
    2. associate--l+63.1%

      \[\leadsto \color{blue}{\cos x \cdot -1 + \left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} \]
    3. *-commutative63.1%

      \[\leadsto \color{blue}{-1 \cdot \cos x} + \left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right) \]
    4. neg-mul-163.1%

      \[\leadsto \color{blue}{\left(-\cos x\right)} + \left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right) \]
    5. cos-sum40.1%

      \[\leadsto \left(-\cos x\right) + \color{blue}{\cos \left(x + \varepsilon\right)} \]
    6. +-commutative40.1%

      \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) + \left(-\cos x\right)} \]
    7. sub-neg40.1%

      \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) - \cos x} \]
    8. diff-cos47.4%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
    9. *-commutative47.4%

      \[\leadsto \color{blue}{\left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \cdot -2} \]
  9. Applied egg-rr76.8%

    \[\leadsto \color{blue}{\left(\sin \left(\left(\varepsilon + \left(x - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right) \cdot -2} \]
  10. Final simplification76.8%

    \[\leadsto \left(\sin \left(\left(\varepsilon + \left(x - x\right)\right) \cdot 0.5\right) \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)\right) \cdot -2 \]
  11. Add Preprocessing

Alternative 11: 67.5% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.85 \cdot 10^{-17} \lor \neg \left(x \leq 4 \cdot 10^{-41}\right):\\ \;\;\;\;\sin x \cdot \left(-\varepsilon\right)\\ \mathbf{else}:\\ \;\;\;\;-2 \cdot {\sin \left(\varepsilon \cdot 0.5\right)}^{2}\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (or (<= x -1.85e-17) (not (<= x 4e-41)))
   (* (sin x) (- eps))
   (* -2.0 (pow (sin (* eps 0.5)) 2.0))))
double code(double x, double eps) {
	double tmp;
	if ((x <= -1.85e-17) || !(x <= 4e-41)) {
		tmp = sin(x) * -eps;
	} else {
		tmp = -2.0 * pow(sin((eps * 0.5)), 2.0);
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if ((x <= (-1.85d-17)) .or. (.not. (x <= 4d-41))) then
        tmp = sin(x) * -eps
    else
        tmp = (-2.0d0) * (sin((eps * 0.5d0)) ** 2.0d0)
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if ((x <= -1.85e-17) || !(x <= 4e-41)) {
		tmp = Math.sin(x) * -eps;
	} else {
		tmp = -2.0 * Math.pow(Math.sin((eps * 0.5)), 2.0);
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if (x <= -1.85e-17) or not (x <= 4e-41):
		tmp = math.sin(x) * -eps
	else:
		tmp = -2.0 * math.pow(math.sin((eps * 0.5)), 2.0)
	return tmp
function code(x, eps)
	tmp = 0.0
	if ((x <= -1.85e-17) || !(x <= 4e-41))
		tmp = Float64(sin(x) * Float64(-eps));
	else
		tmp = Float64(-2.0 * (sin(Float64(eps * 0.5)) ^ 2.0));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if ((x <= -1.85e-17) || ~((x <= 4e-41)))
		tmp = sin(x) * -eps;
	else
		tmp = -2.0 * (sin((eps * 0.5)) ^ 2.0);
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[Or[LessEqual[x, -1.85e-17], N[Not[LessEqual[x, 4e-41]], $MachinePrecision]], N[(N[Sin[x], $MachinePrecision] * (-eps)), $MachinePrecision], N[(-2.0 * N[Power[N[Sin[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.85 \cdot 10^{-17} \lor \neg \left(x \leq 4 \cdot 10^{-41}\right):\\
\;\;\;\;\sin x \cdot \left(-\varepsilon\right)\\

\mathbf{else}:\\
\;\;\;\;-2 \cdot {\sin \left(\varepsilon \cdot 0.5\right)}^{2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.8499999999999999e-17 or 4.00000000000000002e-41 < x

    1. Initial program 10.1%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in eps around 0 52.7%

      \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)} \]
    4. Step-by-step derivation
      1. mul-1-neg52.7%

        \[\leadsto \color{blue}{-\varepsilon \cdot \sin x} \]
      2. *-commutative52.7%

        \[\leadsto -\color{blue}{\sin x \cdot \varepsilon} \]
      3. distribute-rgt-neg-in52.7%

        \[\leadsto \color{blue}{\sin x \cdot \left(-\varepsilon\right)} \]
    5. Simplified52.7%

      \[\leadsto \color{blue}{\sin x \cdot \left(-\varepsilon\right)} \]

    if -1.8499999999999999e-17 < x < 4.00000000000000002e-41

    1. Initial program 77.6%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. diff-cos95.7%

        \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      2. div-inv95.7%

        \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      3. associate--l+95.7%

        \[\leadsto -2 \cdot \left(\sin \left(\color{blue}{\left(x + \left(\varepsilon - x\right)\right)} \cdot \frac{1}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      4. metadata-eval95.7%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      5. div-inv95.7%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
      6. +-commutative95.7%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\color{blue}{\left(\varepsilon + x\right)} + x\right) \cdot \frac{1}{2}\right)\right) \]
      7. associate-+l+95.7%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(\varepsilon + \left(x + x\right)\right)} \cdot \frac{1}{2}\right)\right) \]
      8. metadata-eval95.7%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
    4. Applied egg-rr95.7%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right)} \]
    5. Step-by-step derivation
      1. associate-*r*95.7%

        \[\leadsto \color{blue}{\left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)} \]
      2. *-commutative95.7%

        \[\leadsto \color{blue}{\sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right)} \]
      3. *-commutative95.7%

        \[\leadsto \sin \color{blue}{\left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)} \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      4. +-commutative95.7%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      5. count-295.7%

        \[\leadsto \sin \left(0.5 \cdot \left(\color{blue}{2 \cdot x} + \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      6. fma-def95.7%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\mathsf{fma}\left(2, x, \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      7. sub-neg95.7%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(\varepsilon + \left(-x\right)\right)}\right) \cdot 0.5\right)\right) \]
      8. mul-1-neg95.7%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon + \color{blue}{-1 \cdot x}\right)\right) \cdot 0.5\right)\right) \]
      9. +-commutative95.7%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(-1 \cdot x + \varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      10. associate-+r+99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(\left(x + -1 \cdot x\right) + \varepsilon\right)} \cdot 0.5\right)\right) \]
      11. mul-1-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\left(x + \color{blue}{\left(-x\right)}\right) + \varepsilon\right) \cdot 0.5\right)\right) \]
      12. sub-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{\left(x - x\right)} + \varepsilon\right) \cdot 0.5\right)\right) \]
      13. +-inverses99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{0} + \varepsilon\right) \cdot 0.5\right)\right) \]
      14. remove-double-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \color{blue}{\left(-\left(-\varepsilon\right)\right)}\right) \cdot 0.5\right)\right) \]
      15. mul-1-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \left(-\color{blue}{-1 \cdot \varepsilon}\right)\right) \cdot 0.5\right)\right) \]
      16. sub-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(0 - -1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      17. neg-sub099.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(--1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      18. mul-1-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(-\color{blue}{\left(-\varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      19. remove-double-neg99.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\varepsilon} \cdot 0.5\right)\right) \]
    6. Simplified99.6%

      \[\leadsto \color{blue}{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)} \]
    7. Taylor expanded in x around 0 95.2%

      \[\leadsto \color{blue}{-2 \cdot {\sin \left(0.5 \cdot \varepsilon\right)}^{2}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification71.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.85 \cdot 10^{-17} \lor \neg \left(x \leq 4 \cdot 10^{-41}\right):\\ \;\;\;\;\sin x \cdot \left(-\varepsilon\right)\\ \mathbf{else}:\\ \;\;\;\;-2 \cdot {\sin \left(\varepsilon \cdot 0.5\right)}^{2}\\ \end{array} \]
  5. Add Preprocessing

Alternative 12: 66.9% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := -1 + \cos \varepsilon\\ \mathbf{if}\;\varepsilon \leq -0.00078:\\ \;\;\;\;t_0\\ \mathbf{elif}\;\varepsilon \leq 3.6 \cdot 10^{-18}:\\ \;\;\;\;\sin x \cdot \left(-\varepsilon\right)\\ \mathbf{elif}\;\varepsilon \leq 0.000135:\\ \;\;\;\;-0.5 \cdot {\varepsilon}^{2}\\ \mathbf{else}:\\ \;\;\;\;t_0\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (+ -1.0 (cos eps))))
   (if (<= eps -0.00078)
     t_0
     (if (<= eps 3.6e-18)
       (* (sin x) (- eps))
       (if (<= eps 0.000135) (* -0.5 (pow eps 2.0)) t_0)))))
double code(double x, double eps) {
	double t_0 = -1.0 + cos(eps);
	double tmp;
	if (eps <= -0.00078) {
		tmp = t_0;
	} else if (eps <= 3.6e-18) {
		tmp = sin(x) * -eps;
	} else if (eps <= 0.000135) {
		tmp = -0.5 * pow(eps, 2.0);
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (-1.0d0) + cos(eps)
    if (eps <= (-0.00078d0)) then
        tmp = t_0
    else if (eps <= 3.6d-18) then
        tmp = sin(x) * -eps
    else if (eps <= 0.000135d0) then
        tmp = (-0.5d0) * (eps ** 2.0d0)
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double t_0 = -1.0 + Math.cos(eps);
	double tmp;
	if (eps <= -0.00078) {
		tmp = t_0;
	} else if (eps <= 3.6e-18) {
		tmp = Math.sin(x) * -eps;
	} else if (eps <= 0.000135) {
		tmp = -0.5 * Math.pow(eps, 2.0);
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x, eps):
	t_0 = -1.0 + math.cos(eps)
	tmp = 0
	if eps <= -0.00078:
		tmp = t_0
	elif eps <= 3.6e-18:
		tmp = math.sin(x) * -eps
	elif eps <= 0.000135:
		tmp = -0.5 * math.pow(eps, 2.0)
	else:
		tmp = t_0
	return tmp
function code(x, eps)
	t_0 = Float64(-1.0 + cos(eps))
	tmp = 0.0
	if (eps <= -0.00078)
		tmp = t_0;
	elseif (eps <= 3.6e-18)
		tmp = Float64(sin(x) * Float64(-eps));
	elseif (eps <= 0.000135)
		tmp = Float64(-0.5 * (eps ^ 2.0));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x, eps)
	t_0 = -1.0 + cos(eps);
	tmp = 0.0;
	if (eps <= -0.00078)
		tmp = t_0;
	elseif (eps <= 3.6e-18)
		tmp = sin(x) * -eps;
	elseif (eps <= 0.000135)
		tmp = -0.5 * (eps ^ 2.0);
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_, eps_] := Block[{t$95$0 = N[(-1.0 + N[Cos[eps], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[eps, -0.00078], t$95$0, If[LessEqual[eps, 3.6e-18], N[(N[Sin[x], $MachinePrecision] * (-eps)), $MachinePrecision], If[LessEqual[eps, 0.000135], N[(-0.5 * N[Power[eps, 2.0], $MachinePrecision]), $MachinePrecision], t$95$0]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := -1 + \cos \varepsilon\\
\mathbf{if}\;\varepsilon \leq -0.00078:\\
\;\;\;\;t_0\\

\mathbf{elif}\;\varepsilon \leq 3.6 \cdot 10^{-18}:\\
\;\;\;\;\sin x \cdot \left(-\varepsilon\right)\\

\mathbf{elif}\;\varepsilon \leq 0.000135:\\
\;\;\;\;-0.5 \cdot {\varepsilon}^{2}\\

\mathbf{else}:\\
\;\;\;\;t_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if eps < -7.79999999999999986e-4 or 1.35000000000000002e-4 < eps

    1. Initial program 54.5%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 54.6%

      \[\leadsto \color{blue}{\cos \varepsilon - 1} \]

    if -7.79999999999999986e-4 < eps < 3.6000000000000001e-18

    1. Initial program 25.7%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in eps around 0 86.6%

      \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)} \]
    4. Step-by-step derivation
      1. mul-1-neg86.6%

        \[\leadsto \color{blue}{-\varepsilon \cdot \sin x} \]
      2. *-commutative86.6%

        \[\leadsto -\color{blue}{\sin x \cdot \varepsilon} \]
      3. distribute-rgt-neg-in86.6%

        \[\leadsto \color{blue}{\sin x \cdot \left(-\varepsilon\right)} \]
    5. Simplified86.6%

      \[\leadsto \color{blue}{\sin x \cdot \left(-\varepsilon\right)} \]

    if 3.6000000000000001e-18 < eps < 1.35000000000000002e-4

    1. Initial program 13.0%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 13.0%

      \[\leadsto \color{blue}{\cos \varepsilon - 1} \]
    4. Taylor expanded in eps around 0 97.5%

      \[\leadsto \color{blue}{-0.5 \cdot {\varepsilon}^{2}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification70.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.00078:\\ \;\;\;\;-1 + \cos \varepsilon\\ \mathbf{elif}\;\varepsilon \leq 3.6 \cdot 10^{-18}:\\ \;\;\;\;\sin x \cdot \left(-\varepsilon\right)\\ \mathbf{elif}\;\varepsilon \leq 0.000135:\\ \;\;\;\;-0.5 \cdot {\varepsilon}^{2}\\ \mathbf{else}:\\ \;\;\;\;-1 + \cos \varepsilon\\ \end{array} \]
  5. Add Preprocessing

Alternative 13: 46.2% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.00012 \lor \neg \left(\varepsilon \leq 0.000135\right):\\ \;\;\;\;-1 + \cos \varepsilon\\ \mathbf{else}:\\ \;\;\;\;-0.5 \cdot {\varepsilon}^{2}\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (or (<= eps -0.00012) (not (<= eps 0.000135)))
   (+ -1.0 (cos eps))
   (* -0.5 (pow eps 2.0))))
double code(double x, double eps) {
	double tmp;
	if ((eps <= -0.00012) || !(eps <= 0.000135)) {
		tmp = -1.0 + cos(eps);
	} else {
		tmp = -0.5 * pow(eps, 2.0);
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if ((eps <= (-0.00012d0)) .or. (.not. (eps <= 0.000135d0))) then
        tmp = (-1.0d0) + cos(eps)
    else
        tmp = (-0.5d0) * (eps ** 2.0d0)
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if ((eps <= -0.00012) || !(eps <= 0.000135)) {
		tmp = -1.0 + Math.cos(eps);
	} else {
		tmp = -0.5 * Math.pow(eps, 2.0);
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if (eps <= -0.00012) or not (eps <= 0.000135):
		tmp = -1.0 + math.cos(eps)
	else:
		tmp = -0.5 * math.pow(eps, 2.0)
	return tmp
function code(x, eps)
	tmp = 0.0
	if ((eps <= -0.00012) || !(eps <= 0.000135))
		tmp = Float64(-1.0 + cos(eps));
	else
		tmp = Float64(-0.5 * (eps ^ 2.0));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if ((eps <= -0.00012) || ~((eps <= 0.000135)))
		tmp = -1.0 + cos(eps);
	else
		tmp = -0.5 * (eps ^ 2.0);
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[Or[LessEqual[eps, -0.00012], N[Not[LessEqual[eps, 0.000135]], $MachinePrecision]], N[(-1.0 + N[Cos[eps], $MachinePrecision]), $MachinePrecision], N[(-0.5 * N[Power[eps, 2.0], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\varepsilon \leq -0.00012 \lor \neg \left(\varepsilon \leq 0.000135\right):\\
\;\;\;\;-1 + \cos \varepsilon\\

\mathbf{else}:\\
\;\;\;\;-0.5 \cdot {\varepsilon}^{2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if eps < -1.20000000000000003e-4 or 1.35000000000000002e-4 < eps

    1. Initial program 54.5%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 54.6%

      \[\leadsto \color{blue}{\cos \varepsilon - 1} \]

    if -1.20000000000000003e-4 < eps < 1.35000000000000002e-4

    1. Initial program 25.0%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 25.1%

      \[\leadsto \color{blue}{\cos \varepsilon - 1} \]
    4. Taylor expanded in eps around 0 41.1%

      \[\leadsto \color{blue}{-0.5 \cdot {\varepsilon}^{2}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification48.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.00012 \lor \neg \left(\varepsilon \leq 0.000135\right):\\ \;\;\;\;-1 + \cos \varepsilon\\ \mathbf{else}:\\ \;\;\;\;-0.5 \cdot {\varepsilon}^{2}\\ \end{array} \]
  5. Add Preprocessing

Alternative 14: 38.1% accurate, 2.0× speedup?

\[\begin{array}{l} \\ -1 + \cos \varepsilon \end{array} \]
(FPCore (x eps) :precision binary64 (+ -1.0 (cos eps)))
double code(double x, double eps) {
	return -1.0 + cos(eps);
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = (-1.0d0) + cos(eps)
end function
public static double code(double x, double eps) {
	return -1.0 + Math.cos(eps);
}
def code(x, eps):
	return -1.0 + math.cos(eps)
function code(x, eps)
	return Float64(-1.0 + cos(eps))
end
function tmp = code(x, eps)
	tmp = -1.0 + cos(eps);
end
code[x_, eps_] := N[(-1.0 + N[Cos[eps], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
-1 + \cos \varepsilon
\end{array}
Derivation
  1. Initial program 40.1%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0 40.2%

    \[\leadsto \color{blue}{\cos \varepsilon - 1} \]
  4. Final simplification40.2%

    \[\leadsto -1 + \cos \varepsilon \]
  5. Add Preprocessing

Alternative 15: 12.5% accurate, 205.0× speedup?

\[\begin{array}{l} \\ 0 \end{array} \]
(FPCore (x eps) :precision binary64 0.0)
double code(double x, double eps) {
	return 0.0;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = 0.0d0
end function
public static double code(double x, double eps) {
	return 0.0;
}
def code(x, eps):
	return 0.0
function code(x, eps)
	return 0.0
end
function tmp = code(x, eps)
	tmp = 0.0;
end
code[x_, eps_] := 0.0
\begin{array}{l}

\\
0
\end{array}
Derivation
  1. Initial program 40.1%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0 40.2%

    \[\leadsto \color{blue}{\cos \varepsilon - 1} \]
  4. Taylor expanded in eps around 0 13.6%

    \[\leadsto \color{blue}{1} - 1 \]
  5. Final simplification13.6%

    \[\leadsto 0 \]
  6. Add Preprocessing

Reproduce

?
herbie shell --seed 2024018 
(FPCore (x eps)
  :name "2cos (problem 3.3.5)"
  :precision binary64
  (- (cos (+ x eps)) (cos x)))