2cos (problem 3.3.5)

Percentage Accurate: 51.7% → 99.6%
Time: 17.8s
Alternatives: 10
Speedup: 41.0×

Specification

?
\[\left(\left(-10000 \leq x \land x \leq 10000\right) \land 10^{-16} \cdot \left|x\right| < \varepsilon\right) \land \varepsilon < \left|x\right|\]
\[\begin{array}{l} \\ \cos \left(x + \varepsilon\right) - \cos x \end{array} \]
(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 10 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: 51.7% 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: 99.6% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \varepsilon \cdot \left(0.5 + -0.020833333333333332 \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\\ \left(\left(\sin x \cdot \cos \left(\varepsilon \cdot 0.5\right)\right) \cdot t\_0 + t\_0 \cdot \left(\cos x \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)\right) \cdot -2 \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (* eps (+ 0.5 (* -0.020833333333333332 (* eps eps))))))
   (*
    (+
     (* (* (sin x) (cos (* eps 0.5))) t_0)
     (* t_0 (* (cos x) (sin (* eps 0.5)))))
    -2.0)))
double code(double x, double eps) {
	double t_0 = eps * (0.5 + (-0.020833333333333332 * (eps * eps)));
	return (((sin(x) * cos((eps * 0.5))) * t_0) + (t_0 * (cos(x) * sin((eps * 0.5))))) * -2.0;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: t_0
    t_0 = eps * (0.5d0 + ((-0.020833333333333332d0) * (eps * eps)))
    code = (((sin(x) * cos((eps * 0.5d0))) * t_0) + (t_0 * (cos(x) * sin((eps * 0.5d0))))) * (-2.0d0)
end function
public static double code(double x, double eps) {
	double t_0 = eps * (0.5 + (-0.020833333333333332 * (eps * eps)));
	return (((Math.sin(x) * Math.cos((eps * 0.5))) * t_0) + (t_0 * (Math.cos(x) * Math.sin((eps * 0.5))))) * -2.0;
}
def code(x, eps):
	t_0 = eps * (0.5 + (-0.020833333333333332 * (eps * eps)))
	return (((math.sin(x) * math.cos((eps * 0.5))) * t_0) + (t_0 * (math.cos(x) * math.sin((eps * 0.5))))) * -2.0
function code(x, eps)
	t_0 = Float64(eps * Float64(0.5 + Float64(-0.020833333333333332 * Float64(eps * eps))))
	return Float64(Float64(Float64(Float64(sin(x) * cos(Float64(eps * 0.5))) * t_0) + Float64(t_0 * Float64(cos(x) * sin(Float64(eps * 0.5))))) * -2.0)
end
function tmp = code(x, eps)
	t_0 = eps * (0.5 + (-0.020833333333333332 * (eps * eps)));
	tmp = (((sin(x) * cos((eps * 0.5))) * t_0) + (t_0 * (cos(x) * sin((eps * 0.5))))) * -2.0;
end
code[x_, eps_] := Block[{t$95$0 = N[(eps * N[(0.5 + N[(-0.020833333333333332 * N[(eps * eps), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(N[(N[Sin[x], $MachinePrecision] * N[Cos[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * t$95$0), $MachinePrecision] + N[(t$95$0 * N[(N[Cos[x], $MachinePrecision] * N[Sin[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * -2.0), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \varepsilon \cdot \left(0.5 + -0.020833333333333332 \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\\
\left(\left(\sin x \cdot \cos \left(\varepsilon \cdot 0.5\right)\right) \cdot t\_0 + t\_0 \cdot \left(\cos x \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)\right) \cdot -2
\end{array}
\end{array}
Derivation
  1. Initial program 48.0%

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

      \[\leadsto -2 \cdot \color{blue}{\left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
    2. *-commutativeN/A

      \[\leadsto \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \cdot \color{blue}{-2} \]
    3. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right), \color{blue}{-2}\right) \]
  4. Applied egg-rr99.7%

    \[\leadsto \color{blue}{\left(\sin \left(\frac{\varepsilon + 0}{2}\right) \cdot \sin \left(\frac{\varepsilon + x \cdot 2}{2}\right)\right) \cdot -2} \]
  5. Taylor expanded in eps around 0

    \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\color{blue}{\left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot {\varepsilon}^{2}\right)\right)}, \mathsf{sin.f64}\left(\mathsf{/.f64}\left(\mathsf{+.f64}\left(\varepsilon, \mathsf{*.f64}\left(x, 2\right)\right), 2\right)\right)\right), -2\right) \]
  6. Step-by-step derivation
    1. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \left(\frac{1}{2} + \frac{-1}{48} \cdot {\varepsilon}^{2}\right)\right), \mathsf{sin.f64}\left(\mathsf{/.f64}\left(\mathsf{+.f64}\left(\varepsilon, \mathsf{*.f64}\left(x, 2\right)\right), 2\right)\right)\right), -2\right) \]
    2. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{-1}{48} \cdot {\varepsilon}^{2}\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{/.f64}\left(\mathsf{+.f64}\left(\varepsilon, \mathsf{*.f64}\left(x, 2\right)\right), 2\right)\right)\right), -2\right) \]
    3. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \left({\varepsilon}^{2}\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{/.f64}\left(\mathsf{+.f64}\left(\varepsilon, \mathsf{*.f64}\left(x, 2\right)\right), 2\right)\right)\right), -2\right) \]
    4. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{/.f64}\left(\mathsf{+.f64}\left(\varepsilon, \mathsf{*.f64}\left(x, 2\right)\right), 2\right)\right)\right), -2\right) \]
    5. *-lowering-*.f6499.7%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{/.f64}\left(\mathsf{+.f64}\left(\varepsilon, \mathsf{*.f64}\left(x, 2\right)\right), 2\right)\right)\right), -2\right) \]
  7. Simplified99.7%

    \[\leadsto \left(\color{blue}{\left(\varepsilon \cdot \left(0.5 + -0.020833333333333332 \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)} \cdot \sin \left(\frac{\varepsilon + x \cdot 2}{2}\right)\right) \cdot -2 \]
  8. Taylor expanded in eps around inf

    \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \color{blue}{\sin \left(\frac{1}{2} \cdot \left(\varepsilon + 2 \cdot x\right)\right)}\right), -2\right) \]
  9. Step-by-step derivation
    1. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \sin \left(\frac{1}{2} \cdot \left(\varepsilon + \left(\mathsf{neg}\left(-2\right)\right) \cdot x\right)\right)\right), -2\right) \]
    2. cancel-sign-sub-invN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \sin \left(\frac{1}{2} \cdot \left(\varepsilon - -2 \cdot x\right)\right)\right), -2\right) \]
    3. sin-lowering-sin.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\left(\frac{1}{2} \cdot \left(\varepsilon - -2 \cdot x\right)\right)\right)\right), -2\right) \]
    4. cancel-sign-sub-invN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\left(\frac{1}{2} \cdot \left(\varepsilon + \left(\mathsf{neg}\left(-2\right)\right) \cdot x\right)\right)\right)\right), -2\right) \]
    5. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\left(\frac{1}{2} \cdot \left(\varepsilon + 2 \cdot x\right)\right)\right)\right), -2\right) \]
    6. +-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\left(\frac{1}{2} \cdot \left(2 \cdot x + \varepsilon\right)\right)\right)\right), -2\right) \]
    7. distribute-lft-inN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\left(\frac{1}{2} \cdot \left(2 \cdot x\right) + \frac{1}{2} \cdot \varepsilon\right)\right)\right), -2\right) \]
    8. associate-*r*N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\left(\left(\frac{1}{2} \cdot 2\right) \cdot x + \frac{1}{2} \cdot \varepsilon\right)\right)\right), -2\right) \]
    9. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\left(1 \cdot x + \frac{1}{2} \cdot \varepsilon\right)\right)\right), -2\right) \]
    10. *-lft-identityN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\left(x + \frac{1}{2} \cdot \varepsilon\right)\right)\right), -2\right) \]
    11. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \left(\frac{1}{2} \cdot \varepsilon\right)\right)\right)\right), -2\right) \]
    12. *-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \left(\varepsilon \cdot \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    13. *-lowering-*.f6499.7%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
  10. Simplified99.7%

    \[\leadsto \left(\left(\varepsilon \cdot \left(0.5 + -0.020833333333333332 \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right) \cdot \color{blue}{\sin \left(x + \varepsilon \cdot 0.5\right)}\right) \cdot -2 \]
  11. Step-by-step derivation
    1. sin-sumN/A

      \[\leadsto \mathsf{*.f64}\left(\left(\left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right) \cdot \left(\sin x \cdot \cos \left(\varepsilon \cdot \frac{1}{2}\right) + \cos x \cdot \sin \left(\varepsilon \cdot \frac{1}{2}\right)\right)\right), -2\right) \]
    2. distribute-rgt-inN/A

      \[\leadsto \mathsf{*.f64}\left(\left(\left(\sin x \cdot \cos \left(\varepsilon \cdot \frac{1}{2}\right)\right) \cdot \left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right) + \left(\cos x \cdot \sin \left(\varepsilon \cdot \frac{1}{2}\right)\right) \cdot \left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right), -2\right) \]
    3. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(\left(\left(\sin x \cdot \cos \left(\varepsilon \cdot \frac{1}{2}\right)\right) \cdot \left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right), \left(\left(\cos x \cdot \sin \left(\varepsilon \cdot \frac{1}{2}\right)\right) \cdot \left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right)\right), -2\right) \]
    4. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\left(\sin x \cdot \cos \left(\varepsilon \cdot \frac{1}{2}\right)\right), \left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right), \left(\left(\cos x \cdot \sin \left(\varepsilon \cdot \frac{1}{2}\right)\right) \cdot \left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right)\right), -2\right) \]
    5. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\sin x, \cos \left(\varepsilon \cdot \frac{1}{2}\right)\right), \left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right), \left(\left(\cos x \cdot \sin \left(\varepsilon \cdot \frac{1}{2}\right)\right) \cdot \left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right)\right), -2\right) \]
    6. sin-lowering-sin.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \cos \left(\varepsilon \cdot \frac{1}{2}\right)\right), \left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right), \left(\left(\cos x \cdot \sin \left(\varepsilon \cdot \frac{1}{2}\right)\right) \cdot \left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right)\right), -2\right) \]
    7. cos-lowering-cos.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \mathsf{cos.f64}\left(\left(\varepsilon \cdot \frac{1}{2}\right)\right)\right), \left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right), \left(\left(\cos x \cdot \sin \left(\varepsilon \cdot \frac{1}{2}\right)\right) \cdot \left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right)\right), -2\right) \]
    8. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \mathsf{cos.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right), \left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right), \left(\left(\cos x \cdot \sin \left(\varepsilon \cdot \frac{1}{2}\right)\right) \cdot \left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right)\right), -2\right) \]
    9. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \mathsf{cos.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right), \mathsf{*.f64}\left(\varepsilon, \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right), \left(\left(\cos x \cdot \sin \left(\varepsilon \cdot \frac{1}{2}\right)\right) \cdot \left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right)\right), -2\right) \]
    10. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \mathsf{cos.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right), \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right)\right), \left(\left(\cos x \cdot \sin \left(\varepsilon \cdot \frac{1}{2}\right)\right) \cdot \left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right)\right), -2\right) \]
    11. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \mathsf{cos.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right), \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right)\right), \left(\left(\cos x \cdot \sin \left(\varepsilon \cdot \frac{1}{2}\right)\right) \cdot \left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right)\right), -2\right) \]
    12. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \mathsf{cos.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right), \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right)\right), \left(\left(\cos x \cdot \sin \left(\varepsilon \cdot \frac{1}{2}\right)\right) \cdot \left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right)\right), -2\right) \]
    13. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \mathsf{cos.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right), \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right)\right), \mathsf{*.f64}\left(\left(\cos x \cdot \sin \left(\varepsilon \cdot \frac{1}{2}\right)\right), \left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right)\right), -2\right) \]
  12. Applied egg-rr99.8%

    \[\leadsto \color{blue}{\left(\left(\sin x \cdot \cos \left(\varepsilon \cdot 0.5\right)\right) \cdot \left(\varepsilon \cdot \left(0.5 + -0.020833333333333332 \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right) + \left(\cos x \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \cdot \left(\varepsilon \cdot \left(0.5 + -0.020833333333333332 \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right)} \cdot -2 \]
  13. Final simplification99.8%

    \[\leadsto \left(\left(\sin x \cdot \cos \left(\varepsilon \cdot 0.5\right)\right) \cdot \left(\varepsilon \cdot \left(0.5 + -0.020833333333333332 \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right) + \left(\varepsilon \cdot \left(0.5 + -0.020833333333333332 \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right) \cdot \left(\cos x \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)\right) \cdot -2 \]
  14. Add Preprocessing

Alternative 2: 99.5% accurate, 1.8× speedup?

\[\begin{array}{l} \\ -2 \cdot \left(\left(\varepsilon \cdot \left(0.5 + -0.020833333333333332 \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right) \cdot \sin \left(x + \varepsilon \cdot 0.5\right)\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (*
  -2.0
  (*
   (* eps (+ 0.5 (* -0.020833333333333332 (* eps eps))))
   (sin (+ x (* eps 0.5))))))
double code(double x, double eps) {
	return -2.0 * ((eps * (0.5 + (-0.020833333333333332 * (eps * eps)))) * sin((x + (eps * 0.5))));
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = (-2.0d0) * ((eps * (0.5d0 + ((-0.020833333333333332d0) * (eps * eps)))) * sin((x + (eps * 0.5d0))))
end function
public static double code(double x, double eps) {
	return -2.0 * ((eps * (0.5 + (-0.020833333333333332 * (eps * eps)))) * Math.sin((x + (eps * 0.5))));
}
def code(x, eps):
	return -2.0 * ((eps * (0.5 + (-0.020833333333333332 * (eps * eps)))) * math.sin((x + (eps * 0.5))))
function code(x, eps)
	return Float64(-2.0 * Float64(Float64(eps * Float64(0.5 + Float64(-0.020833333333333332 * Float64(eps * eps)))) * sin(Float64(x + Float64(eps * 0.5)))))
end
function tmp = code(x, eps)
	tmp = -2.0 * ((eps * (0.5 + (-0.020833333333333332 * (eps * eps)))) * sin((x + (eps * 0.5))));
end
code[x_, eps_] := N[(-2.0 * N[(N[(eps * N[(0.5 + N[(-0.020833333333333332 * N[(eps * eps), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Sin[N[(x + N[(eps * 0.5), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
-2 \cdot \left(\left(\varepsilon \cdot \left(0.5 + -0.020833333333333332 \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right) \cdot \sin \left(x + \varepsilon \cdot 0.5\right)\right)
\end{array}
Derivation
  1. Initial program 48.0%

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

      \[\leadsto -2 \cdot \color{blue}{\left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
    2. *-commutativeN/A

      \[\leadsto \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \cdot \color{blue}{-2} \]
    3. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right), \color{blue}{-2}\right) \]
  4. Applied egg-rr99.7%

    \[\leadsto \color{blue}{\left(\sin \left(\frac{\varepsilon + 0}{2}\right) \cdot \sin \left(\frac{\varepsilon + x \cdot 2}{2}\right)\right) \cdot -2} \]
  5. Taylor expanded in eps around 0

    \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\color{blue}{\left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot {\varepsilon}^{2}\right)\right)}, \mathsf{sin.f64}\left(\mathsf{/.f64}\left(\mathsf{+.f64}\left(\varepsilon, \mathsf{*.f64}\left(x, 2\right)\right), 2\right)\right)\right), -2\right) \]
  6. Step-by-step derivation
    1. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \left(\frac{1}{2} + \frac{-1}{48} \cdot {\varepsilon}^{2}\right)\right), \mathsf{sin.f64}\left(\mathsf{/.f64}\left(\mathsf{+.f64}\left(\varepsilon, \mathsf{*.f64}\left(x, 2\right)\right), 2\right)\right)\right), -2\right) \]
    2. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{-1}{48} \cdot {\varepsilon}^{2}\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{/.f64}\left(\mathsf{+.f64}\left(\varepsilon, \mathsf{*.f64}\left(x, 2\right)\right), 2\right)\right)\right), -2\right) \]
    3. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \left({\varepsilon}^{2}\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{/.f64}\left(\mathsf{+.f64}\left(\varepsilon, \mathsf{*.f64}\left(x, 2\right)\right), 2\right)\right)\right), -2\right) \]
    4. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{/.f64}\left(\mathsf{+.f64}\left(\varepsilon, \mathsf{*.f64}\left(x, 2\right)\right), 2\right)\right)\right), -2\right) \]
    5. *-lowering-*.f6499.7%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{/.f64}\left(\mathsf{+.f64}\left(\varepsilon, \mathsf{*.f64}\left(x, 2\right)\right), 2\right)\right)\right), -2\right) \]
  7. Simplified99.7%

    \[\leadsto \left(\color{blue}{\left(\varepsilon \cdot \left(0.5 + -0.020833333333333332 \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)} \cdot \sin \left(\frac{\varepsilon + x \cdot 2}{2}\right)\right) \cdot -2 \]
  8. Taylor expanded in eps around inf

    \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \color{blue}{\sin \left(\frac{1}{2} \cdot \left(\varepsilon + 2 \cdot x\right)\right)}\right), -2\right) \]
  9. Step-by-step derivation
    1. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \sin \left(\frac{1}{2} \cdot \left(\varepsilon + \left(\mathsf{neg}\left(-2\right)\right) \cdot x\right)\right)\right), -2\right) \]
    2. cancel-sign-sub-invN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \sin \left(\frac{1}{2} \cdot \left(\varepsilon - -2 \cdot x\right)\right)\right), -2\right) \]
    3. sin-lowering-sin.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\left(\frac{1}{2} \cdot \left(\varepsilon - -2 \cdot x\right)\right)\right)\right), -2\right) \]
    4. cancel-sign-sub-invN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\left(\frac{1}{2} \cdot \left(\varepsilon + \left(\mathsf{neg}\left(-2\right)\right) \cdot x\right)\right)\right)\right), -2\right) \]
    5. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\left(\frac{1}{2} \cdot \left(\varepsilon + 2 \cdot x\right)\right)\right)\right), -2\right) \]
    6. +-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\left(\frac{1}{2} \cdot \left(2 \cdot x + \varepsilon\right)\right)\right)\right), -2\right) \]
    7. distribute-lft-inN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\left(\frac{1}{2} \cdot \left(2 \cdot x\right) + \frac{1}{2} \cdot \varepsilon\right)\right)\right), -2\right) \]
    8. associate-*r*N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\left(\left(\frac{1}{2} \cdot 2\right) \cdot x + \frac{1}{2} \cdot \varepsilon\right)\right)\right), -2\right) \]
    9. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\left(1 \cdot x + \frac{1}{2} \cdot \varepsilon\right)\right)\right), -2\right) \]
    10. *-lft-identityN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\left(x + \frac{1}{2} \cdot \varepsilon\right)\right)\right), -2\right) \]
    11. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \left(\frac{1}{2} \cdot \varepsilon\right)\right)\right)\right), -2\right) \]
    12. *-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \left(\varepsilon \cdot \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    13. *-lowering-*.f6499.7%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
  10. Simplified99.7%

    \[\leadsto \left(\left(\varepsilon \cdot \left(0.5 + -0.020833333333333332 \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right) \cdot \color{blue}{\sin \left(x + \varepsilon \cdot 0.5\right)}\right) \cdot -2 \]
  11. Final simplification99.7%

    \[\leadsto -2 \cdot \left(\left(\varepsilon \cdot \left(0.5 + -0.020833333333333332 \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right) \cdot \sin \left(x + \varepsilon \cdot 0.5\right)\right) \]
  12. Add Preprocessing

Alternative 3: 99.3% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \sin \left(x + \varepsilon \cdot 0.5\right) \cdot \left(0 - \varepsilon\right) \end{array} \]
(FPCore (x eps) :precision binary64 (* (sin (+ x (* eps 0.5))) (- 0.0 eps)))
double code(double x, double eps) {
	return sin((x + (eps * 0.5))) * (0.0 - eps);
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = sin((x + (eps * 0.5d0))) * (0.0d0 - eps)
end function
public static double code(double x, double eps) {
	return Math.sin((x + (eps * 0.5))) * (0.0 - eps);
}
def code(x, eps):
	return math.sin((x + (eps * 0.5))) * (0.0 - eps)
function code(x, eps)
	return Float64(sin(Float64(x + Float64(eps * 0.5))) * Float64(0.0 - eps))
end
function tmp = code(x, eps)
	tmp = sin((x + (eps * 0.5))) * (0.0 - eps);
end
code[x_, eps_] := N[(N[Sin[N[(x + N[(eps * 0.5), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[(0.0 - eps), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\sin \left(x + \varepsilon \cdot 0.5\right) \cdot \left(0 - \varepsilon\right)
\end{array}
Derivation
  1. Initial program 48.0%

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

      \[\leadsto -2 \cdot \color{blue}{\left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
    2. *-commutativeN/A

      \[\leadsto \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \cdot \color{blue}{-2} \]
    3. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right), \color{blue}{-2}\right) \]
  4. Applied egg-rr99.7%

    \[\leadsto \color{blue}{\left(\sin \left(\frac{\varepsilon + 0}{2}\right) \cdot \sin \left(\frac{\varepsilon + x \cdot 2}{2}\right)\right) \cdot -2} \]
  5. Taylor expanded in eps around 0

    \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\color{blue}{\left(\frac{1}{2} \cdot \varepsilon\right)}, \mathsf{sin.f64}\left(\mathsf{/.f64}\left(\mathsf{+.f64}\left(\varepsilon, \mathsf{*.f64}\left(x, 2\right)\right), 2\right)\right)\right), -2\right) \]
  6. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\left(\varepsilon \cdot \frac{1}{2}\right), \mathsf{sin.f64}\left(\mathsf{/.f64}\left(\mathsf{+.f64}\left(\varepsilon, \mathsf{*.f64}\left(x, 2\right)\right), 2\right)\right)\right), -2\right) \]
    2. *-lowering-*.f6499.7%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right), \mathsf{sin.f64}\left(\mathsf{/.f64}\left(\mathsf{+.f64}\left(\varepsilon, \mathsf{*.f64}\left(x, 2\right)\right), 2\right)\right)\right), -2\right) \]
  7. Simplified99.7%

    \[\leadsto \left(\color{blue}{\left(\varepsilon \cdot 0.5\right)} \cdot \sin \left(\frac{\varepsilon + x \cdot 2}{2}\right)\right) \cdot -2 \]
  8. Taylor expanded in eps around inf

    \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot \sin \left(\frac{1}{2} \cdot \left(\varepsilon + 2 \cdot x\right)\right)\right)} \]
  9. Step-by-step derivation
    1. mul-1-negN/A

      \[\leadsto \mathsf{neg}\left(\varepsilon \cdot \sin \left(\frac{1}{2} \cdot \left(\varepsilon + 2 \cdot x\right)\right)\right) \]
    2. *-commutativeN/A

      \[\leadsto \mathsf{neg}\left(\sin \left(\frac{1}{2} \cdot \left(\varepsilon + 2 \cdot x\right)\right) \cdot \varepsilon\right) \]
    3. metadata-evalN/A

      \[\leadsto \mathsf{neg}\left(\sin \left(\frac{1}{2} \cdot \left(\varepsilon + \left(\mathsf{neg}\left(-2\right)\right) \cdot x\right)\right) \cdot \varepsilon\right) \]
    4. cancel-sign-sub-invN/A

      \[\leadsto \mathsf{neg}\left(\sin \left(\frac{1}{2} \cdot \left(\varepsilon - -2 \cdot x\right)\right) \cdot \varepsilon\right) \]
    5. distribute-rgt-neg-inN/A

      \[\leadsto \sin \left(\frac{1}{2} \cdot \left(\varepsilon - -2 \cdot x\right)\right) \cdot \color{blue}{\left(\mathsf{neg}\left(\varepsilon\right)\right)} \]
    6. cancel-sign-sub-invN/A

      \[\leadsto \sin \left(\frac{1}{2} \cdot \left(\varepsilon + \left(\mathsf{neg}\left(-2\right)\right) \cdot x\right)\right) \cdot \left(\mathsf{neg}\left(\varepsilon\right)\right) \]
    7. metadata-evalN/A

      \[\leadsto \sin \left(\frac{1}{2} \cdot \left(\varepsilon + 2 \cdot x\right)\right) \cdot \left(\mathsf{neg}\left(\varepsilon\right)\right) \]
    8. +-commutativeN/A

      \[\leadsto \sin \left(\frac{1}{2} \cdot \left(2 \cdot x + \varepsilon\right)\right) \cdot \left(\mathsf{neg}\left(\varepsilon\right)\right) \]
    9. distribute-rgt-inN/A

      \[\leadsto \sin \left(\left(2 \cdot x\right) \cdot \frac{1}{2} + \varepsilon \cdot \frac{1}{2}\right) \cdot \left(\mathsf{neg}\left(\varepsilon\right)\right) \]
    10. *-commutativeN/A

      \[\leadsto \sin \left(\left(x \cdot 2\right) \cdot \frac{1}{2} + \varepsilon \cdot \frac{1}{2}\right) \cdot \left(\mathsf{neg}\left(\varepsilon\right)\right) \]
    11. associate-*l*N/A

      \[\leadsto \sin \left(x \cdot \left(2 \cdot \frac{1}{2}\right) + \varepsilon \cdot \frac{1}{2}\right) \cdot \left(\mathsf{neg}\left(\varepsilon\right)\right) \]
    12. metadata-evalN/A

      \[\leadsto \sin \left(x \cdot 1 + \varepsilon \cdot \frac{1}{2}\right) \cdot \left(\mathsf{neg}\left(\varepsilon\right)\right) \]
    13. *-rgt-identityN/A

      \[\leadsto \sin \left(x + \varepsilon \cdot \frac{1}{2}\right) \cdot \left(\mathsf{neg}\left(\varepsilon\right)\right) \]
    14. *-commutativeN/A

      \[\leadsto \sin \left(x + \frac{1}{2} \cdot \varepsilon\right) \cdot \left(\mathsf{neg}\left(\varepsilon\right)\right) \]
    15. mul-1-negN/A

      \[\leadsto \sin \left(x + \frac{1}{2} \cdot \varepsilon\right) \cdot \left(-1 \cdot \color{blue}{\varepsilon}\right) \]
    16. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\sin \left(x + \frac{1}{2} \cdot \varepsilon\right), \color{blue}{\left(-1 \cdot \varepsilon\right)}\right) \]
  10. Simplified99.7%

    \[\leadsto \color{blue}{\sin \left(x + \varepsilon \cdot 0.5\right) \cdot \left(0 - \varepsilon\right)} \]
  11. Add Preprocessing

Alternative 4: 79.2% accurate, 2.0× speedup?

\[\begin{array}{l} \\ 0 - \sin x \cdot \varepsilon \end{array} \]
(FPCore (x eps) :precision binary64 (- 0.0 (* (sin x) eps)))
double code(double x, double eps) {
	return 0.0 - (sin(x) * eps);
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = 0.0d0 - (sin(x) * eps)
end function
public static double code(double x, double eps) {
	return 0.0 - (Math.sin(x) * eps);
}
def code(x, eps):
	return 0.0 - (math.sin(x) * eps)
function code(x, eps)
	return Float64(0.0 - Float64(sin(x) * eps))
end
function tmp = code(x, eps)
	tmp = 0.0 - (sin(x) * eps);
end
code[x_, eps_] := N[(0.0 - N[(N[Sin[x], $MachinePrecision] * eps), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0 - \sin x \cdot \varepsilon
\end{array}
Derivation
  1. Initial program 48.0%

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

    \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)} \]
  4. Step-by-step derivation
    1. associate-*r*N/A

      \[\leadsto \left(-1 \cdot \varepsilon\right) \cdot \color{blue}{\sin x} \]
    2. *-commutativeN/A

      \[\leadsto \sin x \cdot \color{blue}{\left(-1 \cdot \varepsilon\right)} \]
    3. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\sin x, \color{blue}{\left(-1 \cdot \varepsilon\right)}\right) \]
    4. sin-lowering-sin.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \left(\color{blue}{-1} \cdot \varepsilon\right)\right) \]
    5. mul-1-negN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \left(\mathsf{neg}\left(\varepsilon\right)\right)\right) \]
    6. neg-sub0N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \left(0 - \color{blue}{\varepsilon}\right)\right) \]
    7. --lowering--.f6477.8%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \mathsf{\_.f64}\left(0, \color{blue}{\varepsilon}\right)\right) \]
  5. Simplified77.8%

    \[\leadsto \color{blue}{\sin x \cdot \left(0 - \varepsilon\right)} \]
  6. Step-by-step derivation
    1. sub0-negN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \left(\mathsf{neg}\left(\varepsilon\right)\right)\right) \]
    2. neg-lowering-neg.f6477.8%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \mathsf{neg.f64}\left(\varepsilon\right)\right) \]
  7. Applied egg-rr77.8%

    \[\leadsto \sin x \cdot \color{blue}{\left(-\varepsilon\right)} \]
  8. Final simplification77.8%

    \[\leadsto 0 - \sin x \cdot \varepsilon \]
  9. Add Preprocessing

Alternative 5: 78.6% accurate, 8.9× speedup?

\[\begin{array}{l} \\ \varepsilon \cdot \left(x \cdot \left(-1 - x \cdot \left(x \cdot \left(-0.16666666666666666 + \left(x \cdot x\right) \cdot \left(0.008333333333333333 + \left(x \cdot x\right) \cdot -0.0001984126984126984\right)\right)\right)\right)\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (*
  eps
  (*
   x
   (-
    -1.0
    (*
     x
     (*
      x
      (+
       -0.16666666666666666
       (*
        (* x x)
        (+ 0.008333333333333333 (* (* x x) -0.0001984126984126984))))))))))
double code(double x, double eps) {
	return eps * (x * (-1.0 - (x * (x * (-0.16666666666666666 + ((x * x) * (0.008333333333333333 + ((x * x) * -0.0001984126984126984))))))));
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = eps * (x * ((-1.0d0) - (x * (x * ((-0.16666666666666666d0) + ((x * x) * (0.008333333333333333d0 + ((x * x) * (-0.0001984126984126984d0)))))))))
end function
public static double code(double x, double eps) {
	return eps * (x * (-1.0 - (x * (x * (-0.16666666666666666 + ((x * x) * (0.008333333333333333 + ((x * x) * -0.0001984126984126984))))))));
}
def code(x, eps):
	return eps * (x * (-1.0 - (x * (x * (-0.16666666666666666 + ((x * x) * (0.008333333333333333 + ((x * x) * -0.0001984126984126984))))))))
function code(x, eps)
	return Float64(eps * Float64(x * Float64(-1.0 - Float64(x * Float64(x * Float64(-0.16666666666666666 + Float64(Float64(x * x) * Float64(0.008333333333333333 + Float64(Float64(x * x) * -0.0001984126984126984)))))))))
end
function tmp = code(x, eps)
	tmp = eps * (x * (-1.0 - (x * (x * (-0.16666666666666666 + ((x * x) * (0.008333333333333333 + ((x * x) * -0.0001984126984126984))))))));
end
code[x_, eps_] := N[(eps * N[(x * N[(-1.0 - N[(x * N[(x * N[(-0.16666666666666666 + N[(N[(x * x), $MachinePrecision] * N[(0.008333333333333333 + N[(N[(x * x), $MachinePrecision] * -0.0001984126984126984), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\varepsilon \cdot \left(x \cdot \left(-1 - x \cdot \left(x \cdot \left(-0.16666666666666666 + \left(x \cdot x\right) \cdot \left(0.008333333333333333 + \left(x \cdot x\right) \cdot -0.0001984126984126984\right)\right)\right)\right)\right)
\end{array}
Derivation
  1. Initial program 48.0%

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

    \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)} \]
  4. Step-by-step derivation
    1. associate-*r*N/A

      \[\leadsto \left(-1 \cdot \varepsilon\right) \cdot \color{blue}{\sin x} \]
    2. *-commutativeN/A

      \[\leadsto \sin x \cdot \color{blue}{\left(-1 \cdot \varepsilon\right)} \]
    3. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\sin x, \color{blue}{\left(-1 \cdot \varepsilon\right)}\right) \]
    4. sin-lowering-sin.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \left(\color{blue}{-1} \cdot \varepsilon\right)\right) \]
    5. mul-1-negN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \left(\mathsf{neg}\left(\varepsilon\right)\right)\right) \]
    6. neg-sub0N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \left(0 - \color{blue}{\varepsilon}\right)\right) \]
    7. --lowering--.f6477.8%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \mathsf{\_.f64}\left(0, \color{blue}{\varepsilon}\right)\right) \]
  5. Simplified77.8%

    \[\leadsto \color{blue}{\sin x \cdot \left(0 - \varepsilon\right)} \]
  6. Taylor expanded in x around 0

    \[\leadsto \mathsf{*.f64}\left(\color{blue}{\left(x \cdot \left(1 + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right)\right)}, \mathsf{\_.f64}\left(0, \varepsilon\right)\right) \]
  7. Step-by-step derivation
    1. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \left(1 + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right)\right), \mathsf{\_.f64}\left(\color{blue}{0}, \varepsilon\right)\right) \]
    2. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \left({x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right)\right)\right), \mathsf{\_.f64}\left(0, \varepsilon\right)\right) \]
    3. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \left(\left(x \cdot x\right) \cdot \left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right)\right)\right), \mathsf{\_.f64}\left(0, \varepsilon\right)\right) \]
    4. associate-*l*N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \left(x \cdot \left(x \cdot \left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right)\right)\right)\right), \mathsf{\_.f64}\left(0, \varepsilon\right)\right) \]
    5. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \left(x \cdot \left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right)\right)\right)\right), \mathsf{\_.f64}\left(0, \varepsilon\right)\right) \]
    6. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right)\right)\right)\right), \mathsf{\_.f64}\left(0, \varepsilon\right)\right) \]
    7. sub-negN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right) + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right)\right)\right)\right)\right)\right), \mathsf{\_.f64}\left(0, \varepsilon\right)\right) \]
    8. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right) + \frac{-1}{6}\right)\right)\right)\right)\right), \mathsf{\_.f64}\left(0, \varepsilon\right)\right) \]
    9. +-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \left(\frac{-1}{6} + {x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right)\right)\right)\right)\right)\right), \mathsf{\_.f64}\left(0, \varepsilon\right)\right) \]
    10. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-1}{6}, \left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right)\right)\right)\right)\right)\right)\right), \mathsf{\_.f64}\left(0, \varepsilon\right)\right) \]
    11. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-1}{6}, \mathsf{*.f64}\left(\left({x}^{2}\right), \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right)\right)\right)\right)\right)\right)\right), \mathsf{\_.f64}\left(0, \varepsilon\right)\right) \]
    12. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-1}{6}, \mathsf{*.f64}\left(\left(x \cdot x\right), \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right)\right)\right)\right)\right)\right)\right), \mathsf{\_.f64}\left(0, \varepsilon\right)\right) \]
    13. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-1}{6}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right)\right)\right)\right)\right)\right)\right), \mathsf{\_.f64}\left(0, \varepsilon\right)\right) \]
    14. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-1}{6}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{120}, \left(\frac{-1}{5040} \cdot {x}^{2}\right)\right)\right)\right)\right)\right)\right)\right), \mathsf{\_.f64}\left(0, \varepsilon\right)\right) \]
    15. *-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-1}{6}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{120}, \left({x}^{2} \cdot \frac{-1}{5040}\right)\right)\right)\right)\right)\right)\right)\right), \mathsf{\_.f64}\left(0, \varepsilon\right)\right) \]
    16. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-1}{6}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{120}, \mathsf{*.f64}\left(\left({x}^{2}\right), \frac{-1}{5040}\right)\right)\right)\right)\right)\right)\right)\right), \mathsf{\_.f64}\left(0, \varepsilon\right)\right) \]
    17. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-1}{6}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{120}, \mathsf{*.f64}\left(\left(x \cdot x\right), \frac{-1}{5040}\right)\right)\right)\right)\right)\right)\right)\right), \mathsf{\_.f64}\left(0, \varepsilon\right)\right) \]
    18. *-lowering-*.f6477.4%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-1}{6}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{120}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \frac{-1}{5040}\right)\right)\right)\right)\right)\right)\right)\right), \mathsf{\_.f64}\left(0, \varepsilon\right)\right) \]
  8. Simplified77.4%

    \[\leadsto \color{blue}{\left(x \cdot \left(1 + x \cdot \left(x \cdot \left(-0.16666666666666666 + \left(x \cdot x\right) \cdot \left(0.008333333333333333 + \left(x \cdot x\right) \cdot -0.0001984126984126984\right)\right)\right)\right)\right)} \cdot \left(0 - \varepsilon\right) \]
  9. Final simplification77.4%

    \[\leadsto \varepsilon \cdot \left(x \cdot \left(-1 - x \cdot \left(x \cdot \left(-0.16666666666666666 + \left(x \cdot x\right) \cdot \left(0.008333333333333333 + \left(x \cdot x\right) \cdot -0.0001984126984126984\right)\right)\right)\right)\right) \]
  10. Add Preprocessing

Alternative 6: 78.5% accurate, 18.6× speedup?

\[\begin{array}{l} \\ x \cdot \left(\varepsilon \cdot \left(-1 + \left(x \cdot x\right) \cdot 0.16666666666666666\right)\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (* x (* eps (+ -1.0 (* (* x x) 0.16666666666666666)))))
double code(double x, double eps) {
	return x * (eps * (-1.0 + ((x * x) * 0.16666666666666666)));
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = x * (eps * ((-1.0d0) + ((x * x) * 0.16666666666666666d0)))
end function
public static double code(double x, double eps) {
	return x * (eps * (-1.0 + ((x * x) * 0.16666666666666666)));
}
def code(x, eps):
	return x * (eps * (-1.0 + ((x * x) * 0.16666666666666666)))
function code(x, eps)
	return Float64(x * Float64(eps * Float64(-1.0 + Float64(Float64(x * x) * 0.16666666666666666))))
end
function tmp = code(x, eps)
	tmp = x * (eps * (-1.0 + ((x * x) * 0.16666666666666666)));
end
code[x_, eps_] := N[(x * N[(eps * N[(-1.0 + N[(N[(x * x), $MachinePrecision] * 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x \cdot \left(\varepsilon \cdot \left(-1 + \left(x \cdot x\right) \cdot 0.16666666666666666\right)\right)
\end{array}
Derivation
  1. Initial program 48.0%

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

    \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)} \]
  4. Step-by-step derivation
    1. associate-*r*N/A

      \[\leadsto \left(-1 \cdot \varepsilon\right) \cdot \color{blue}{\sin x} \]
    2. *-commutativeN/A

      \[\leadsto \sin x \cdot \color{blue}{\left(-1 \cdot \varepsilon\right)} \]
    3. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\sin x, \color{blue}{\left(-1 \cdot \varepsilon\right)}\right) \]
    4. sin-lowering-sin.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \left(\color{blue}{-1} \cdot \varepsilon\right)\right) \]
    5. mul-1-negN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \left(\mathsf{neg}\left(\varepsilon\right)\right)\right) \]
    6. neg-sub0N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \left(0 - \color{blue}{\varepsilon}\right)\right) \]
    7. --lowering--.f6477.8%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \mathsf{\_.f64}\left(0, \color{blue}{\varepsilon}\right)\right) \]
  5. Simplified77.8%

    \[\leadsto \color{blue}{\sin x \cdot \left(0 - \varepsilon\right)} \]
  6. Taylor expanded in x around 0

    \[\leadsto \color{blue}{x \cdot \left(-1 \cdot \varepsilon + \frac{1}{6} \cdot \left(\varepsilon \cdot {x}^{2}\right)\right)} \]
  7. Step-by-step derivation
    1. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(x, \color{blue}{\left(-1 \cdot \varepsilon + \frac{1}{6} \cdot \left(\varepsilon \cdot {x}^{2}\right)\right)}\right) \]
    2. *-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\varepsilon \cdot -1 + \color{blue}{\frac{1}{6}} \cdot \left(\varepsilon \cdot {x}^{2}\right)\right)\right) \]
    3. *-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\varepsilon \cdot -1 + \left(\varepsilon \cdot {x}^{2}\right) \cdot \color{blue}{\frac{1}{6}}\right)\right) \]
    4. associate-*l*N/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\varepsilon \cdot -1 + \varepsilon \cdot \color{blue}{\left({x}^{2} \cdot \frac{1}{6}\right)}\right)\right) \]
    5. distribute-lft-outN/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\varepsilon \cdot \color{blue}{\left(-1 + {x}^{2} \cdot \frac{1}{6}\right)}\right)\right) \]
    6. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \color{blue}{\left(-1 + {x}^{2} \cdot \frac{1}{6}\right)}\right)\right) \]
    7. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(-1, \color{blue}{\left({x}^{2} \cdot \frac{1}{6}\right)}\right)\right)\right) \]
    8. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(-1, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\frac{1}{6}}\right)\right)\right)\right) \]
    9. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(-1, \mathsf{*.f64}\left(\left(x \cdot x\right), \frac{1}{6}\right)\right)\right)\right) \]
    10. *-lowering-*.f6477.4%

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(-1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \frac{1}{6}\right)\right)\right)\right) \]
  8. Simplified77.4%

    \[\leadsto \color{blue}{x \cdot \left(\varepsilon \cdot \left(-1 + \left(x \cdot x\right) \cdot 0.16666666666666666\right)\right)} \]
  9. Add Preprocessing

Alternative 7: 53.8% accurate, 20.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -7 \cdot 10^{-142}:\\ \;\;\;\;x \cdot \left(x \cdot 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\varepsilon \cdot \left(\varepsilon \cdot -0.5\right)\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (<= x -7e-142) (* x (* x 0.5)) (* eps (* eps -0.5))))
double code(double x, double eps) {
	double tmp;
	if (x <= -7e-142) {
		tmp = x * (x * 0.5);
	} else {
		tmp = eps * (eps * -0.5);
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if (x <= (-7d-142)) then
        tmp = x * (x * 0.5d0)
    else
        tmp = eps * (eps * (-0.5d0))
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if (x <= -7e-142) {
		tmp = x * (x * 0.5);
	} else {
		tmp = eps * (eps * -0.5);
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if x <= -7e-142:
		tmp = x * (x * 0.5)
	else:
		tmp = eps * (eps * -0.5)
	return tmp
function code(x, eps)
	tmp = 0.0
	if (x <= -7e-142)
		tmp = Float64(x * Float64(x * 0.5));
	else
		tmp = Float64(eps * Float64(eps * -0.5));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if (x <= -7e-142)
		tmp = x * (x * 0.5);
	else
		tmp = eps * (eps * -0.5);
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[LessEqual[x, -7e-142], N[(x * N[(x * 0.5), $MachinePrecision]), $MachinePrecision], N[(eps * N[(eps * -0.5), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -7 \cdot 10^{-142}:\\
\;\;\;\;x \cdot \left(x \cdot 0.5\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -7.00000000000000029e-142

    1. Initial program 6.7%

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

      \[\leadsto \mathsf{\_.f64}\left(\mathsf{cos.f64}\left(\mathsf{+.f64}\left(x, \varepsilon\right)\right), \color{blue}{\left(1 + \frac{-1}{2} \cdot {x}^{2}\right)}\right) \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cos.f64}\left(\mathsf{+.f64}\left(x, \varepsilon\right)\right), \mathsf{+.f64}\left(1, \color{blue}{\left(\frac{-1}{2} \cdot {x}^{2}\right)}\right)\right) \]
      2. unpow2N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cos.f64}\left(\mathsf{+.f64}\left(x, \varepsilon\right)\right), \mathsf{+.f64}\left(1, \left(\frac{-1}{2} \cdot \left(x \cdot \color{blue}{x}\right)\right)\right)\right) \]
      3. associate-*r*N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cos.f64}\left(\mathsf{+.f64}\left(x, \varepsilon\right)\right), \mathsf{+.f64}\left(1, \left(\left(\frac{-1}{2} \cdot x\right) \cdot \color{blue}{x}\right)\right)\right) \]
      4. *-commutativeN/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cos.f64}\left(\mathsf{+.f64}\left(x, \varepsilon\right)\right), \mathsf{+.f64}\left(1, \left(x \cdot \color{blue}{\left(\frac{-1}{2} \cdot x\right)}\right)\right)\right) \]
      5. *-lowering-*.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cos.f64}\left(\mathsf{+.f64}\left(x, \varepsilon\right)\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \color{blue}{\left(\frac{-1}{2} \cdot x\right)}\right)\right)\right) \]
      6. *-commutativeN/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cos.f64}\left(\mathsf{+.f64}\left(x, \varepsilon\right)\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \left(x \cdot \color{blue}{\frac{-1}{2}}\right)\right)\right)\right) \]
      7. *-lowering-*.f645.7%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cos.f64}\left(\mathsf{+.f64}\left(x, \varepsilon\right)\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{\frac{-1}{2}}\right)\right)\right)\right) \]
    5. Simplified5.7%

      \[\leadsto \cos \left(x + \varepsilon\right) - \color{blue}{\left(1 + x \cdot \left(x \cdot -0.5\right)\right)} \]
    6. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{1}{2} \cdot {x}^{2}} \]
    7. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto {x}^{2} \cdot \color{blue}{\frac{1}{2}} \]
      2. unpow2N/A

        \[\leadsto \left(x \cdot x\right) \cdot \frac{1}{2} \]
      3. associate-*l*N/A

        \[\leadsto x \cdot \color{blue}{\left(x \cdot \frac{1}{2}\right)} \]
      4. *-lowering-*.f64N/A

        \[\leadsto \mathsf{*.f64}\left(x, \color{blue}{\left(x \cdot \frac{1}{2}\right)}\right) \]
      5. *-lowering-*.f6412.4%

        \[\leadsto \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{\frac{1}{2}}\right)\right) \]
    8. Simplified12.4%

      \[\leadsto \color{blue}{x \cdot \left(x \cdot 0.5\right)} \]

    if -7.00000000000000029e-142 < x

    1. Initial program 63.5%

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

      \[\leadsto \color{blue}{\cos \varepsilon - 1} \]
    4. Step-by-step derivation
      1. sub-negN/A

        \[\leadsto \cos \varepsilon + \color{blue}{\left(\mathsf{neg}\left(1\right)\right)} \]
      2. metadata-evalN/A

        \[\leadsto \cos \varepsilon + -1 \]
      3. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\cos \varepsilon, \color{blue}{-1}\right) \]
      4. cos-lowering-cos.f6463.2%

        \[\leadsto \mathsf{+.f64}\left(\mathsf{cos.f64}\left(\varepsilon\right), -1\right) \]
    5. Simplified63.2%

      \[\leadsto \color{blue}{\cos \varepsilon + -1} \]
    6. Taylor expanded in eps around 0

      \[\leadsto \color{blue}{\frac{-1}{2} \cdot {\varepsilon}^{2}} \]
    7. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto {\varepsilon}^{2} \cdot \color{blue}{\frac{-1}{2}} \]
      2. unpow2N/A

        \[\leadsto \left(\varepsilon \cdot \varepsilon\right) \cdot \frac{-1}{2} \]
      3. associate-*l*N/A

        \[\leadsto \varepsilon \cdot \color{blue}{\left(\varepsilon \cdot \frac{-1}{2}\right)} \]
      4. *-commutativeN/A

        \[\leadsto \varepsilon \cdot \left(\frac{-1}{2} \cdot \color{blue}{\varepsilon}\right) \]
      5. *-lowering-*.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\varepsilon, \color{blue}{\left(\frac{-1}{2} \cdot \varepsilon\right)}\right) \]
      6. *-commutativeN/A

        \[\leadsto \mathsf{*.f64}\left(\varepsilon, \left(\varepsilon \cdot \color{blue}{\frac{-1}{2}}\right)\right) \]
      7. *-lowering-*.f6465.5%

        \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \color{blue}{\frac{-1}{2}}\right)\right) \]
    8. Simplified65.5%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(\varepsilon \cdot -0.5\right)} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 8: 78.3% accurate, 41.0× speedup?

\[\begin{array}{l} \\ 0 - x \cdot \varepsilon \end{array} \]
(FPCore (x eps) :precision binary64 (- 0.0 (* x eps)))
double code(double x, double eps) {
	return 0.0 - (x * eps);
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = 0.0d0 - (x * eps)
end function
public static double code(double x, double eps) {
	return 0.0 - (x * eps);
}
def code(x, eps):
	return 0.0 - (x * eps)
function code(x, eps)
	return Float64(0.0 - Float64(x * eps))
end
function tmp = code(x, eps)
	tmp = 0.0 - (x * eps);
end
code[x_, eps_] := N[(0.0 - N[(x * eps), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0 - x \cdot \varepsilon
\end{array}
Derivation
  1. Initial program 48.0%

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

    \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)} \]
  4. Step-by-step derivation
    1. associate-*r*N/A

      \[\leadsto \left(-1 \cdot \varepsilon\right) \cdot \color{blue}{\sin x} \]
    2. *-commutativeN/A

      \[\leadsto \sin x \cdot \color{blue}{\left(-1 \cdot \varepsilon\right)} \]
    3. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\sin x, \color{blue}{\left(-1 \cdot \varepsilon\right)}\right) \]
    4. sin-lowering-sin.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \left(\color{blue}{-1} \cdot \varepsilon\right)\right) \]
    5. mul-1-negN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \left(\mathsf{neg}\left(\varepsilon\right)\right)\right) \]
    6. neg-sub0N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \left(0 - \color{blue}{\varepsilon}\right)\right) \]
    7. --lowering--.f6477.8%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \mathsf{\_.f64}\left(0, \color{blue}{\varepsilon}\right)\right) \]
  5. Simplified77.8%

    \[\leadsto \color{blue}{\sin x \cdot \left(0 - \varepsilon\right)} \]
  6. Taylor expanded in x around 0

    \[\leadsto \mathsf{*.f64}\left(\color{blue}{x}, \mathsf{\_.f64}\left(0, \varepsilon\right)\right) \]
  7. Step-by-step derivation
    1. Simplified77.1%

      \[\leadsto \color{blue}{x} \cdot \left(0 - \varepsilon\right) \]
    2. Final simplification77.1%

      \[\leadsto 0 - x \cdot \varepsilon \]
    3. Add Preprocessing

    Alternative 9: 51.6% accurate, 41.0× speedup?

    \[\begin{array}{l} \\ \varepsilon \cdot \left(\varepsilon \cdot -0.5\right) \end{array} \]
    (FPCore (x eps) :precision binary64 (* eps (* eps -0.5)))
    double code(double x, double eps) {
    	return eps * (eps * -0.5);
    }
    
    real(8) function code(x, eps)
        real(8), intent (in) :: x
        real(8), intent (in) :: eps
        code = eps * (eps * (-0.5d0))
    end function
    
    public static double code(double x, double eps) {
    	return eps * (eps * -0.5);
    }
    
    def code(x, eps):
    	return eps * (eps * -0.5)
    
    function code(x, eps)
    	return Float64(eps * Float64(eps * -0.5))
    end
    
    function tmp = code(x, eps)
    	tmp = eps * (eps * -0.5);
    end
    
    code[x_, eps_] := N[(eps * N[(eps * -0.5), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \varepsilon \cdot \left(\varepsilon \cdot -0.5\right)
    \end{array}
    
    Derivation
    1. Initial program 48.0%

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

      \[\leadsto \color{blue}{\cos \varepsilon - 1} \]
    4. Step-by-step derivation
      1. sub-negN/A

        \[\leadsto \cos \varepsilon + \color{blue}{\left(\mathsf{neg}\left(1\right)\right)} \]
      2. metadata-evalN/A

        \[\leadsto \cos \varepsilon + -1 \]
      3. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\cos \varepsilon, \color{blue}{-1}\right) \]
      4. cos-lowering-cos.f6447.2%

        \[\leadsto \mathsf{+.f64}\left(\mathsf{cos.f64}\left(\varepsilon\right), -1\right) \]
    5. Simplified47.2%

      \[\leadsto \color{blue}{\cos \varepsilon + -1} \]
    6. Taylor expanded in eps around 0

      \[\leadsto \color{blue}{\frac{-1}{2} \cdot {\varepsilon}^{2}} \]
    7. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto {\varepsilon}^{2} \cdot \color{blue}{\frac{-1}{2}} \]
      2. unpow2N/A

        \[\leadsto \left(\varepsilon \cdot \varepsilon\right) \cdot \frac{-1}{2} \]
      3. associate-*l*N/A

        \[\leadsto \varepsilon \cdot \color{blue}{\left(\varepsilon \cdot \frac{-1}{2}\right)} \]
      4. *-commutativeN/A

        \[\leadsto \varepsilon \cdot \left(\frac{-1}{2} \cdot \color{blue}{\varepsilon}\right) \]
      5. *-lowering-*.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\varepsilon, \color{blue}{\left(\frac{-1}{2} \cdot \varepsilon\right)}\right) \]
      6. *-commutativeN/A

        \[\leadsto \mathsf{*.f64}\left(\varepsilon, \left(\varepsilon \cdot \color{blue}{\frac{-1}{2}}\right)\right) \]
      7. *-lowering-*.f6448.5%

        \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \color{blue}{\frac{-1}{2}}\right)\right) \]
    8. Simplified48.5%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(\varepsilon \cdot -0.5\right)} \]
    9. Add Preprocessing

    Alternative 10: 50.3% 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 48.0%

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

      \[\leadsto \color{blue}{\cos \varepsilon - 1} \]
    4. Step-by-step derivation
      1. sub-negN/A

        \[\leadsto \cos \varepsilon + \color{blue}{\left(\mathsf{neg}\left(1\right)\right)} \]
      2. metadata-evalN/A

        \[\leadsto \cos \varepsilon + -1 \]
      3. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\cos \varepsilon, \color{blue}{-1}\right) \]
      4. cos-lowering-cos.f6447.2%

        \[\leadsto \mathsf{+.f64}\left(\mathsf{cos.f64}\left(\varepsilon\right), -1\right) \]
    5. Simplified47.2%

      \[\leadsto \color{blue}{\cos \varepsilon + -1} \]
    6. Taylor expanded in eps around 0

      \[\leadsto \mathsf{+.f64}\left(\color{blue}{1}, -1\right) \]
    7. Step-by-step derivation
      1. Simplified47.2%

        \[\leadsto \color{blue}{1} + -1 \]
      2. Step-by-step derivation
        1. metadata-eval47.2%

          \[\leadsto 0 \]
      3. Applied egg-rr47.2%

        \[\leadsto \color{blue}{0} \]
      4. Add Preprocessing

      Developer Target 1: 99.7% accurate, 1.0× speedup?

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

      Reproduce

      ?
      herbie shell --seed 2024149 
      (FPCore (x eps)
        :name "2cos (problem 3.3.5)"
        :precision binary64
        :pre (and (and (and (<= -10000.0 x) (<= x 10000.0)) (< (* 1e-16 (fabs x)) eps)) (< eps (fabs x)))
      
        :alt
        (! :herbie-platform default (* -2 (sin (+ x (/ eps 2))) (sin (/ eps 2))))
      
        (- (cos (+ x eps)) (cos x)))