2cos (problem 3.3.5)

Percentage Accurate: 51.7% → 99.6%
Time: 16.6s
Alternatives: 14
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 14 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, 0.6× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(\sin x \cdot \left(-1 + \varepsilon \cdot \left(\varepsilon \cdot 0.16666666666666666\right)\right), \varepsilon, \left(\varepsilon \cdot -0.5\right) \cdot \left(\varepsilon \cdot \cos x\right)\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (fma
  (* (sin x) (+ -1.0 (* eps (* eps 0.16666666666666666))))
  eps
  (* (* eps -0.5) (* eps (cos x)))))
double code(double x, double eps) {
	return fma((sin(x) * (-1.0 + (eps * (eps * 0.16666666666666666)))), eps, ((eps * -0.5) * (eps * cos(x))));
}
function code(x, eps)
	return fma(Float64(sin(x) * Float64(-1.0 + Float64(eps * Float64(eps * 0.16666666666666666)))), eps, Float64(Float64(eps * -0.5) * Float64(eps * cos(x))))
end
code[x_, eps_] := N[(N[(N[Sin[x], $MachinePrecision] * N[(-1.0 + N[(eps * N[(eps * 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * eps + N[(N[(eps * -0.5), $MachinePrecision] * N[(eps * N[Cos[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(\sin x \cdot \left(-1 + \varepsilon \cdot \left(\varepsilon \cdot 0.16666666666666666\right)\right), \varepsilon, \left(\varepsilon \cdot -0.5\right) \cdot \left(\varepsilon \cdot \cos x\right)\right)
\end{array}
Derivation
  1. Initial program 56.3%

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

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

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \left(\varepsilon \cdot \left(\frac{-1}{2} \cdot \cos x + \frac{1}{6} \cdot \left(\varepsilon \cdot \sin x\right)\right) + \color{blue}{\left(\mathsf{neg}\left(\sin x\right)\right)}\right)\right) \]
    3. distribute-lft-inN/A

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

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

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

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

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

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

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\frac{-1}{2}, \mathsf{cos.f64}\left(x\right)\right)\right), \left(\varepsilon \cdot \left(\frac{1}{6} \cdot \left(\varepsilon \cdot \sin x\right)\right) + \left(\mathsf{neg}\left(\color{blue}{\sin x}\right)\right)\right)\right)\right) \]
    11. associate-*r*N/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\frac{-1}{2}, \mathsf{cos.f64}\left(x\right)\right)\right), \left(\varepsilon \cdot \left(\left(\frac{1}{6} \cdot \varepsilon\right) \cdot \sin x\right) + \left(\mathsf{neg}\left(\sin x\right)\right)\right)\right)\right) \]
    12. associate-*r*N/A

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\frac{-1}{2}, \mathsf{cos.f64}\left(x\right)\right)\right), \left(\left(\varepsilon \cdot \left(\frac{1}{6} \cdot \varepsilon\right)\right) \cdot \sin x + -1 \cdot \color{blue}{\sin x}\right)\right)\right) \]
  5. Simplified99.5%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\varepsilon \cdot \left(-0.5 \cdot \cos x\right) + \sin x \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot 0.16666666666666666\right) + -1\right)\right)} \]
  6. Step-by-step derivation
    1. +-commutativeN/A

      \[\leadsto \varepsilon \cdot \left(\sin x \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \frac{1}{6}\right) + -1\right) + \color{blue}{\varepsilon \cdot \left(\frac{-1}{2} \cdot \cos x\right)}\right) \]
    2. distribute-lft-inN/A

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

      \[\leadsto \left(\sin x \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \frac{1}{6}\right) + -1\right)\right) \cdot \varepsilon + \color{blue}{\varepsilon} \cdot \left(\varepsilon \cdot \left(\frac{-1}{2} \cdot \cos x\right)\right) \]
    4. fma-defineN/A

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

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

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

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

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

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

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

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

      \[\leadsto \mathsf{fma.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \mathsf{+.f64}\left(-1, \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \frac{1}{6}\right)\right)\right)\right), \varepsilon, \left(\left(\varepsilon \cdot \left(\frac{-1}{2} \cdot \cos x\right)\right) \cdot \varepsilon\right)\right) \]
    13. associate-*r*N/A

      \[\leadsto \mathsf{fma.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \mathsf{+.f64}\left(-1, \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \frac{1}{6}\right)\right)\right)\right), \varepsilon, \left(\left(\left(\varepsilon \cdot \frac{-1}{2}\right) \cdot \cos x\right) \cdot \varepsilon\right)\right) \]
    14. associate-*l*N/A

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

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

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

      \[\leadsto \mathsf{fma.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \mathsf{+.f64}\left(-1, \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \frac{1}{6}\right)\right)\right)\right), \varepsilon, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{-1}{2}\right), \mathsf{*.f64}\left(\cos x, \varepsilon\right)\right)\right) \]
    18. cos-lowering-cos.f6499.7%

      \[\leadsto \mathsf{fma.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(x\right), \mathsf{+.f64}\left(-1, \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \frac{1}{6}\right)\right)\right)\right), \varepsilon, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{-1}{2}\right), \mathsf{*.f64}\left(\mathsf{cos.f64}\left(x\right), \varepsilon\right)\right)\right) \]
  7. Applied egg-rr99.7%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\sin x \cdot \left(-1 + \varepsilon \cdot \left(\varepsilon \cdot 0.16666666666666666\right)\right), \varepsilon, \left(\varepsilon \cdot -0.5\right) \cdot \left(\cos x \cdot \varepsilon\right)\right)} \]
  8. Final simplification99.7%

    \[\leadsto \mathsf{fma}\left(\sin x \cdot \left(-1 + \varepsilon \cdot \left(\varepsilon \cdot 0.16666666666666666\right)\right), \varepsilon, \left(\varepsilon \cdot -0.5\right) \cdot \left(\varepsilon \cdot \cos x\right)\right) \]
  9. Add Preprocessing

Alternative 2: 99.7% accurate, 1.0× speedup?

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

\\
\left(\sin \left(\varepsilon \cdot 0.5\right) \cdot \sin \left(x + \varepsilon \cdot 0.5\right)\right) \cdot -2
\end{array}
Derivation
  1. Initial program 56.3%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  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-rr99.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \left(\varepsilon \cdot \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    17. *-lowering-*.f6499.6%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
  7. Simplified99.6%

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

Alternative 3: 99.6% accurate, 1.6× speedup?

\[\begin{array}{l} \\ -2 \cdot \left(\sin \left(x + \varepsilon \cdot 0.5\right) \cdot \left(\varepsilon \cdot \left(0.5 + \varepsilon \cdot \left(\varepsilon \cdot \left(-0.020833333333333332 + \left(\varepsilon \cdot \varepsilon\right) \cdot \left(0.00026041666666666666 + \left(\varepsilon \cdot \varepsilon\right) \cdot -1.5500992063492063 \cdot 10^{-6}\right)\right)\right)\right)\right)\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (*
  -2.0
  (*
   (sin (+ x (* eps 0.5)))
   (*
    eps
    (+
     0.5
     (*
      eps
      (*
       eps
       (+
        -0.020833333333333332
        (*
         (* eps eps)
         (+
          0.00026041666666666666
          (* (* eps eps) -1.5500992063492063e-6)))))))))))
double code(double x, double eps) {
	return -2.0 * (sin((x + (eps * 0.5))) * (eps * (0.5 + (eps * (eps * (-0.020833333333333332 + ((eps * eps) * (0.00026041666666666666 + ((eps * eps) * -1.5500992063492063e-6)))))))));
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = (-2.0d0) * (sin((x + (eps * 0.5d0))) * (eps * (0.5d0 + (eps * (eps * ((-0.020833333333333332d0) + ((eps * eps) * (0.00026041666666666666d0 + ((eps * eps) * (-1.5500992063492063d-6))))))))))
end function
public static double code(double x, double eps) {
	return -2.0 * (Math.sin((x + (eps * 0.5))) * (eps * (0.5 + (eps * (eps * (-0.020833333333333332 + ((eps * eps) * (0.00026041666666666666 + ((eps * eps) * -1.5500992063492063e-6)))))))));
}
def code(x, eps):
	return -2.0 * (math.sin((x + (eps * 0.5))) * (eps * (0.5 + (eps * (eps * (-0.020833333333333332 + ((eps * eps) * (0.00026041666666666666 + ((eps * eps) * -1.5500992063492063e-6)))))))))
function code(x, eps)
	return Float64(-2.0 * Float64(sin(Float64(x + Float64(eps * 0.5))) * Float64(eps * Float64(0.5 + Float64(eps * Float64(eps * Float64(-0.020833333333333332 + Float64(Float64(eps * eps) * Float64(0.00026041666666666666 + Float64(Float64(eps * eps) * -1.5500992063492063e-6))))))))))
end
function tmp = code(x, eps)
	tmp = -2.0 * (sin((x + (eps * 0.5))) * (eps * (0.5 + (eps * (eps * (-0.020833333333333332 + ((eps * eps) * (0.00026041666666666666 + ((eps * eps) * -1.5500992063492063e-6)))))))));
end
code[x_, eps_] := N[(-2.0 * N[(N[Sin[N[(x + N[(eps * 0.5), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[(eps * N[(0.5 + N[(eps * N[(eps * N[(-0.020833333333333332 + N[(N[(eps * eps), $MachinePrecision] * N[(0.00026041666666666666 + N[(N[(eps * eps), $MachinePrecision] * -1.5500992063492063e-6), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
-2 \cdot \left(\sin \left(x + \varepsilon \cdot 0.5\right) \cdot \left(\varepsilon \cdot \left(0.5 + \varepsilon \cdot \left(\varepsilon \cdot \left(-0.020833333333333332 + \left(\varepsilon \cdot \varepsilon\right) \cdot \left(0.00026041666666666666 + \left(\varepsilon \cdot \varepsilon\right) \cdot -1.5500992063492063 \cdot 10^{-6}\right)\right)\right)\right)\right)\right)
\end{array}
Derivation
  1. Initial program 56.3%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  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-rr99.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \left(\varepsilon \cdot \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    17. *-lowering-*.f6499.6%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
  7. Simplified99.6%

    \[\leadsto \color{blue}{\left(\sin \left(\varepsilon \cdot 0.5\right) \cdot \sin \left(x + \varepsilon \cdot 0.5\right)\right)} \cdot -2 \]
  8. Taylor expanded in eps around 0

    \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\color{blue}{\left(\varepsilon \cdot \left(\frac{1}{2} + {\varepsilon}^{2} \cdot \left({\varepsilon}^{2} \cdot \left(\frac{1}{3840} + \frac{-1}{645120} \cdot {\varepsilon}^{2}\right) - \frac{1}{48}\right)\right)\right)}, \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
  9. Step-by-step derivation
    1. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \left(\frac{1}{2} + {\varepsilon}^{2} \cdot \left({\varepsilon}^{2} \cdot \left(\frac{1}{3840} + \frac{-1}{645120} \cdot {\varepsilon}^{2}\right) - \frac{1}{48}\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    2. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \left({\varepsilon}^{2} \cdot \left({\varepsilon}^{2} \cdot \left(\frac{1}{3840} + \frac{-1}{645120} \cdot {\varepsilon}^{2}\right) - \frac{1}{48}\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    3. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \left(\left(\varepsilon \cdot \varepsilon\right) \cdot \left({\varepsilon}^{2} \cdot \left(\frac{1}{3840} + \frac{-1}{645120} \cdot {\varepsilon}^{2}\right) - \frac{1}{48}\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    4. associate-*l*N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \left(\varepsilon \cdot \left(\varepsilon \cdot \left({\varepsilon}^{2} \cdot \left(\frac{1}{3840} + \frac{-1}{645120} \cdot {\varepsilon}^{2}\right) - \frac{1}{48}\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    5. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\varepsilon, \left(\varepsilon \cdot \left({\varepsilon}^{2} \cdot \left(\frac{1}{3840} + \frac{-1}{645120} \cdot {\varepsilon}^{2}\right) - \frac{1}{48}\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    6. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \left({\varepsilon}^{2} \cdot \left(\frac{1}{3840} + \frac{-1}{645120} \cdot {\varepsilon}^{2}\right) - \frac{1}{48}\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    7. sub-negN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \left({\varepsilon}^{2} \cdot \left(\frac{1}{3840} + \frac{-1}{645120} \cdot {\varepsilon}^{2}\right) + \left(\mathsf{neg}\left(\frac{1}{48}\right)\right)\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    8. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \left({\varepsilon}^{2} \cdot \left(\frac{1}{3840} + \frac{-1}{645120} \cdot {\varepsilon}^{2}\right) + \frac{-1}{48}\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    9. +-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \left(\frac{-1}{48} + {\varepsilon}^{2} \cdot \left(\frac{1}{3840} + \frac{-1}{645120} \cdot {\varepsilon}^{2}\right)\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    10. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{48}, \left({\varepsilon}^{2} \cdot \left(\frac{1}{3840} + \frac{-1}{645120} \cdot {\varepsilon}^{2}\right)\right)\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    11. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\left({\varepsilon}^{2}\right), \left(\frac{1}{3840} + \frac{-1}{645120} \cdot {\varepsilon}^{2}\right)\right)\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    12. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\left(\varepsilon \cdot \varepsilon\right), \left(\frac{1}{3840} + \frac{-1}{645120} \cdot {\varepsilon}^{2}\right)\right)\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    13. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \varepsilon\right), \left(\frac{1}{3840} + \frac{-1}{645120} \cdot {\varepsilon}^{2}\right)\right)\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    14. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \varepsilon\right), \mathsf{+.f64}\left(\frac{1}{3840}, \left(\frac{-1}{645120} \cdot {\varepsilon}^{2}\right)\right)\right)\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    15. *-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \varepsilon\right), \mathsf{+.f64}\left(\frac{1}{3840}, \left({\varepsilon}^{2} \cdot \frac{-1}{645120}\right)\right)\right)\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    16. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \varepsilon\right), \mathsf{+.f64}\left(\frac{1}{3840}, \mathsf{*.f64}\left(\left({\varepsilon}^{2}\right), \frac{-1}{645120}\right)\right)\right)\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    17. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \varepsilon\right), \mathsf{+.f64}\left(\frac{1}{3840}, \mathsf{*.f64}\left(\left(\varepsilon \cdot \varepsilon\right), \frac{-1}{645120}\right)\right)\right)\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    18. *-lowering-*.f6499.5%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \varepsilon\right), \mathsf{+.f64}\left(\frac{1}{3840}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \varepsilon\right), \frac{-1}{645120}\right)\right)\right)\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
  10. Simplified99.5%

    \[\leadsto \left(\color{blue}{\left(\varepsilon \cdot \left(0.5 + \varepsilon \cdot \left(\varepsilon \cdot \left(-0.020833333333333332 + \left(\varepsilon \cdot \varepsilon\right) \cdot \left(0.00026041666666666666 + \left(\varepsilon \cdot \varepsilon\right) \cdot -1.5500992063492063 \cdot 10^{-6}\right)\right)\right)\right)\right)} \cdot \sin \left(x + \varepsilon \cdot 0.5\right)\right) \cdot -2 \]
  11. Final simplification99.5%

    \[\leadsto -2 \cdot \left(\sin \left(x + \varepsilon \cdot 0.5\right) \cdot \left(\varepsilon \cdot \left(0.5 + \varepsilon \cdot \left(\varepsilon \cdot \left(-0.020833333333333332 + \left(\varepsilon \cdot \varepsilon\right) \cdot \left(0.00026041666666666666 + \left(\varepsilon \cdot \varepsilon\right) \cdot -1.5500992063492063 \cdot 10^{-6}\right)\right)\right)\right)\right)\right) \]
  12. Add Preprocessing

Alternative 4: 99.6% accurate, 1.7× speedup?

\[\begin{array}{l} \\ -2 \cdot \left(\sin \left(x + \varepsilon \cdot 0.5\right) \cdot \left(\varepsilon \cdot \left(0.5 + \left(\varepsilon \cdot \varepsilon\right) \cdot \left(-0.020833333333333332 + \left(\varepsilon \cdot \varepsilon\right) \cdot 0.00026041666666666666\right)\right)\right)\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (*
  -2.0
  (*
   (sin (+ x (* eps 0.5)))
   (*
    eps
    (+
     0.5
     (*
      (* eps eps)
      (+ -0.020833333333333332 (* (* eps eps) 0.00026041666666666666))))))))
double code(double x, double eps) {
	return -2.0 * (sin((x + (eps * 0.5))) * (eps * (0.5 + ((eps * eps) * (-0.020833333333333332 + ((eps * eps) * 0.00026041666666666666))))));
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = (-2.0d0) * (sin((x + (eps * 0.5d0))) * (eps * (0.5d0 + ((eps * eps) * ((-0.020833333333333332d0) + ((eps * eps) * 0.00026041666666666666d0))))))
end function
public static double code(double x, double eps) {
	return -2.0 * (Math.sin((x + (eps * 0.5))) * (eps * (0.5 + ((eps * eps) * (-0.020833333333333332 + ((eps * eps) * 0.00026041666666666666))))));
}
def code(x, eps):
	return -2.0 * (math.sin((x + (eps * 0.5))) * (eps * (0.5 + ((eps * eps) * (-0.020833333333333332 + ((eps * eps) * 0.00026041666666666666))))))
function code(x, eps)
	return Float64(-2.0 * Float64(sin(Float64(x + Float64(eps * 0.5))) * Float64(eps * Float64(0.5 + Float64(Float64(eps * eps) * Float64(-0.020833333333333332 + Float64(Float64(eps * eps) * 0.00026041666666666666)))))))
end
function tmp = code(x, eps)
	tmp = -2.0 * (sin((x + (eps * 0.5))) * (eps * (0.5 + ((eps * eps) * (-0.020833333333333332 + ((eps * eps) * 0.00026041666666666666))))));
end
code[x_, eps_] := N[(-2.0 * N[(N[Sin[N[(x + N[(eps * 0.5), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[(eps * N[(0.5 + N[(N[(eps * eps), $MachinePrecision] * N[(-0.020833333333333332 + N[(N[(eps * eps), $MachinePrecision] * 0.00026041666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
-2 \cdot \left(\sin \left(x + \varepsilon \cdot 0.5\right) \cdot \left(\varepsilon \cdot \left(0.5 + \left(\varepsilon \cdot \varepsilon\right) \cdot \left(-0.020833333333333332 + \left(\varepsilon \cdot \varepsilon\right) \cdot 0.00026041666666666666\right)\right)\right)\right)
\end{array}
Derivation
  1. Initial program 56.3%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  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-rr99.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \left(\varepsilon \cdot \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    17. *-lowering-*.f6499.6%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
  7. Simplified99.6%

    \[\leadsto \color{blue}{\left(\sin \left(\varepsilon \cdot 0.5\right) \cdot \sin \left(x + \varepsilon \cdot 0.5\right)\right)} \cdot -2 \]
  8. Taylor expanded in eps around 0

    \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\color{blue}{\left(\varepsilon \cdot \left(\frac{1}{2} + {\varepsilon}^{2} \cdot \left(\frac{1}{3840} \cdot {\varepsilon}^{2} - \frac{1}{48}\right)\right)\right)}, \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
  9. Step-by-step derivation
    1. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \left(\frac{1}{2} + {\varepsilon}^{2} \cdot \left(\frac{1}{3840} \cdot {\varepsilon}^{2} - \frac{1}{48}\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    2. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \left({\varepsilon}^{2} \cdot \left(\frac{1}{3840} \cdot {\varepsilon}^{2} - \frac{1}{48}\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    3. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left({\varepsilon}^{2}\right), \left(\frac{1}{3840} \cdot {\varepsilon}^{2} - \frac{1}{48}\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    4. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left(\varepsilon \cdot \varepsilon\right), \left(\frac{1}{3840} \cdot {\varepsilon}^{2} - \frac{1}{48}\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    5. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \varepsilon\right), \left(\frac{1}{3840} \cdot {\varepsilon}^{2} - \frac{1}{48}\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    6. sub-negN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \varepsilon\right), \left(\frac{1}{3840} \cdot {\varepsilon}^{2} + \left(\mathsf{neg}\left(\frac{1}{48}\right)\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    7. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \varepsilon\right), \left(\frac{1}{3840} \cdot {\varepsilon}^{2} + \frac{-1}{48}\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    8. +-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \varepsilon\right), \left(\frac{-1}{48} + \frac{1}{3840} \cdot {\varepsilon}^{2}\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    9. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \varepsilon\right), \mathsf{+.f64}\left(\frac{-1}{48}, \left(\frac{1}{3840} \cdot {\varepsilon}^{2}\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    10. *-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \varepsilon\right), \mathsf{+.f64}\left(\frac{-1}{48}, \left({\varepsilon}^{2} \cdot \frac{1}{3840}\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    11. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \varepsilon\right), \mathsf{+.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\left({\varepsilon}^{2}\right), \frac{1}{3840}\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    12. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \varepsilon\right), \mathsf{+.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\left(\varepsilon \cdot \varepsilon\right), \frac{1}{3840}\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    13. *-lowering-*.f6499.5%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \varepsilon\right), \mathsf{+.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \varepsilon\right), \frac{1}{3840}\right)\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
  10. Simplified99.5%

    \[\leadsto \left(\color{blue}{\left(\varepsilon \cdot \left(0.5 + \left(\varepsilon \cdot \varepsilon\right) \cdot \left(-0.020833333333333332 + \left(\varepsilon \cdot \varepsilon\right) \cdot 0.00026041666666666666\right)\right)\right)} \cdot \sin \left(x + \varepsilon \cdot 0.5\right)\right) \cdot -2 \]
  11. Final simplification99.5%

    \[\leadsto -2 \cdot \left(\sin \left(x + \varepsilon \cdot 0.5\right) \cdot \left(\varepsilon \cdot \left(0.5 + \left(\varepsilon \cdot \varepsilon\right) \cdot \left(-0.020833333333333332 + \left(\varepsilon \cdot \varepsilon\right) \cdot 0.00026041666666666666\right)\right)\right)\right) \]
  12. Add Preprocessing

Alternative 5: 99.5% accurate, 1.8× speedup?

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

\\
-2 \cdot \left(\sin \left(x + \varepsilon \cdot 0.5\right) \cdot \left(\varepsilon \cdot \left(0.5 + -0.020833333333333332 \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right)
\end{array}
Derivation
  1. Initial program 56.3%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  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-rr99.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \left(\varepsilon \cdot \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    17. *-lowering-*.f6499.6%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
  7. Simplified99.6%

    \[\leadsto \color{blue}{\left(\sin \left(\varepsilon \cdot 0.5\right) \cdot \sin \left(x + \varepsilon \cdot 0.5\right)\right)} \cdot -2 \]
  8. Taylor expanded in eps around 0

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

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

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

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

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \left(\varepsilon \cdot \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    5. *-lowering-*.f6499.4%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\frac{-1}{48}, \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right)\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
  10. Simplified99.4%

    \[\leadsto \left(\color{blue}{\left(\varepsilon \cdot \left(0.5 + -0.020833333333333332 \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right)} \cdot \sin \left(x + \varepsilon \cdot 0.5\right)\right) \cdot -2 \]
  11. Final simplification99.4%

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

Alternative 6: 99.3% accurate, 1.8× speedup?

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

\\
-2 \cdot \left(\left(\varepsilon \cdot 0.5\right) \cdot \sin \left(x + \varepsilon \cdot 0.5\right)\right)
\end{array}
Derivation
  1. Initial program 56.3%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  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-rr99.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \left(\varepsilon \cdot \frac{1}{2}\right)\right)\right)\right), -2\right) \]
    17. *-lowering-*.f6499.6%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{sin.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right), \mathsf{sin.f64}\left(\mathsf{+.f64}\left(x, \mathsf{*.f64}\left(\varepsilon, \frac{1}{2}\right)\right)\right)\right), -2\right) \]
  7. Simplified99.6%

    \[\leadsto \color{blue}{\left(\sin \left(\varepsilon \cdot 0.5\right) \cdot \sin \left(x + \varepsilon \cdot 0.5\right)\right)} \cdot -2 \]
  8. Taylor expanded in eps around 0

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

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

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

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

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

Alternative 7: 98.8% accurate, 1.9× speedup?

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

\\
\varepsilon \cdot \left(\varepsilon \cdot -0.5 - \sin x\right)
\end{array}
Derivation
  1. Initial program 56.3%

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

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

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

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

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

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

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

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

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\frac{-1}{2}, \mathsf{cos.f64}\left(x\right)\right)\right), \sin x\right)\right) \]
    9. sin-lowering-sin.f6499.2%

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

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\varepsilon \cdot \left(-0.5 \cdot \cos x\right) - \sin x\right)} \]
  6. Taylor expanded in x around 0

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\left(\varepsilon \cdot \frac{-1}{2}\right), \mathsf{sin.f64}\left(\color{blue}{x}\right)\right)\right) \]
    2. *-lowering-*.f6498.2%

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{-1}{2}\right), \mathsf{sin.f64}\left(\color{blue}{x}\right)\right)\right) \]
  8. Simplified98.2%

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

Alternative 8: 98.2% accurate, 6.2× speedup?

\[\begin{array}{l} \\ \varepsilon \cdot \left(\varepsilon \cdot \left(-0.5 + 0.25 \cdot \left(x \cdot x\right)\right) + x \cdot \left(-1 - \left(x \cdot x\right) \cdot \left(-0.16666666666666666 + \left(x \cdot x\right) \cdot \left(0.008333333333333333 + x \cdot \left(x \cdot -0.0001984126984126984\right)\right)\right)\right)\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (*
  eps
  (+
   (* eps (+ -0.5 (* 0.25 (* x x))))
   (*
    x
    (-
     -1.0
     (*
      (* x x)
      (+
       -0.16666666666666666
       (*
        (* x x)
        (+ 0.008333333333333333 (* x (* x -0.0001984126984126984)))))))))))
double code(double x, double eps) {
	return eps * ((eps * (-0.5 + (0.25 * (x * x)))) + (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 * ((eps * ((-0.5d0) + (0.25d0 * (x * x)))) + (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 * ((eps * (-0.5 + (0.25 * (x * x)))) + (x * (-1.0 - ((x * x) * (-0.16666666666666666 + ((x * x) * (0.008333333333333333 + (x * (x * -0.0001984126984126984)))))))));
}
def code(x, eps):
	return eps * ((eps * (-0.5 + (0.25 * (x * x)))) + (x * (-1.0 - ((x * x) * (-0.16666666666666666 + ((x * x) * (0.008333333333333333 + (x * (x * -0.0001984126984126984)))))))))
function code(x, eps)
	return Float64(eps * Float64(Float64(eps * Float64(-0.5 + Float64(0.25 * Float64(x * x)))) + Float64(x * Float64(-1.0 - Float64(Float64(x * x) * Float64(-0.16666666666666666 + Float64(Float64(x * x) * Float64(0.008333333333333333 + Float64(x * Float64(x * -0.0001984126984126984))))))))))
end
function tmp = code(x, eps)
	tmp = eps * ((eps * (-0.5 + (0.25 * (x * x)))) + (x * (-1.0 - ((x * x) * (-0.16666666666666666 + ((x * x) * (0.008333333333333333 + (x * (x * -0.0001984126984126984)))))))));
end
code[x_, eps_] := N[(eps * N[(N[(eps * N[(-0.5 + N[(0.25 * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(x * N[(-1.0 - N[(N[(x * x), $MachinePrecision] * N[(-0.16666666666666666 + N[(N[(x * x), $MachinePrecision] * N[(0.008333333333333333 + N[(x * N[(x * -0.0001984126984126984), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\varepsilon \cdot \left(\varepsilon \cdot \left(-0.5 + 0.25 \cdot \left(x \cdot x\right)\right) + x \cdot \left(-1 - \left(x \cdot x\right) \cdot \left(-0.16666666666666666 + \left(x \cdot x\right) \cdot \left(0.008333333333333333 + x \cdot \left(x \cdot -0.0001984126984126984\right)\right)\right)\right)\right)
\end{array}
Derivation
  1. Initial program 56.3%

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

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

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

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

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

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

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

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

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\frac{-1}{2}, \mathsf{cos.f64}\left(x\right)\right)\right), \sin x\right)\right) \]
    9. sin-lowering-sin.f6499.2%

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

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\varepsilon \cdot \left(-0.5 \cdot \cos x\right) - \sin x\right)} \]
  6. Taylor expanded in x around 0

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

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\left(\frac{-1}{2} \cdot \varepsilon + \left(\frac{1}{4} \cdot {x}^{2}\right) \cdot \varepsilon\right), \mathsf{sin.f64}\left(x\right)\right)\right) \]
    3. distribute-rgt-outN/A

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\left(\varepsilon \cdot \left(\frac{1}{4} \cdot {x}^{2} + \frac{-1}{2}\right)\right), \mathsf{sin.f64}\left(x\right)\right)\right) \]
    5. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\left(\varepsilon \cdot \left(\frac{1}{4} \cdot {x}^{2} + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)\right)\right), \mathsf{sin.f64}\left(x\right)\right)\right) \]
    6. sub-negN/A

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \left(\frac{1}{4} \cdot {x}^{2} - \frac{1}{2}\right)\right), \mathsf{sin.f64}\left(\color{blue}{x}\right)\right)\right) \]
    8. sub-negN/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \left(\frac{1}{4} \cdot {x}^{2} + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)\right)\right), \mathsf{sin.f64}\left(x\right)\right)\right) \]
    9. metadata-evalN/A

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

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

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

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\frac{1}{4}, \left(x \cdot x\right)\right)\right)\right), \mathsf{sin.f64}\left(x\right)\right)\right) \]
    14. *-lowering-*.f6497.8%

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\frac{1}{4}, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{sin.f64}\left(x\right)\right)\right) \]
  8. Simplified97.8%

    \[\leadsto \varepsilon \cdot \left(\color{blue}{\varepsilon \cdot \left(-0.5 + 0.25 \cdot \left(x \cdot x\right)\right)} - \sin x\right) \]
  9. Taylor expanded in x around 0

    \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\frac{1}{4}, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \color{blue}{\left(x \cdot \left(1 + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right)\right)}\right)\right) \]
  10. Step-by-step derivation
    1. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\frac{1}{4}, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{*.f64}\left(x, \color{blue}{\left(1 + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right)}\right)\right)\right) \]
    2. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\frac{1}{4}, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \color{blue}{\left({x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right)}\right)\right)\right)\right) \]
    3. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\frac{1}{4}, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right) - \frac{1}{6}\right)}\right)\right)\right)\right)\right) \]
    4. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\frac{1}{4}, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\left(x \cdot x\right), \left(\color{blue}{{x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right)} - \frac{1}{6}\right)\right)\right)\right)\right)\right) \]
    5. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\frac{1}{4}, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\color{blue}{{x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right)} - \frac{1}{6}\right)\right)\right)\right)\right)\right) \]
    6. sub-negN/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\frac{1}{4}, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right) + \color{blue}{\left(\mathsf{neg}\left(\frac{1}{6}\right)\right)}\right)\right)\right)\right)\right)\right) \]
    7. metadata-evalN/A

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\frac{1}{4}, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\frac{-1}{6} + \color{blue}{{x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right)\right) \]
    9. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\frac{1}{4}, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{-1}{6}, \color{blue}{\left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right)\right)}\right)\right)\right)\right)\right)\right) \]
    10. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\frac{1}{4}, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{-1}{6}, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right)\right)\right) \]
    11. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\frac{1}{4}, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{-1}{6}, \mathsf{*.f64}\left(\left(x \cdot x\right), \left(\color{blue}{\frac{1}{120}} + \frac{-1}{5040} \cdot {x}^{2}\right)\right)\right)\right)\right)\right)\right)\right) \]
    12. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\frac{1}{4}, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{-1}{6}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\color{blue}{\frac{1}{120}} + \frac{-1}{5040} \cdot {x}^{2}\right)\right)\right)\right)\right)\right)\right)\right) \]
    13. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\frac{1}{4}, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{-1}{6}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{120}, \color{blue}{\left(\frac{-1}{5040} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right)\right)\right)\right) \]
    14. *-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\frac{1}{4}, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{-1}{6}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{120}, \left({x}^{2} \cdot \color{blue}{\frac{-1}{5040}}\right)\right)\right)\right)\right)\right)\right)\right)\right) \]
    15. unpow2N/A

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\frac{1}{4}, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{-1}{6}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{120}, \left(x \cdot \color{blue}{\left(x \cdot \frac{-1}{5040}\right)}\right)\right)\right)\right)\right)\right)\right)\right)\right) \]
    17. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\frac{1}{4}, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{-1}{6}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{120}, \mathsf{*.f64}\left(x, \color{blue}{\left(x \cdot \frac{-1}{5040}\right)}\right)\right)\right)\right)\right)\right)\right)\right)\right) \]
    18. *-lowering-*.f6496.9%

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\frac{1}{4}, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{-1}{6}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{120}, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{\frac{-1}{5040}}\right)\right)\right)\right)\right)\right)\right)\right)\right)\right) \]
  11. Simplified96.9%

    \[\leadsto \varepsilon \cdot \left(\varepsilon \cdot \left(-0.5 + 0.25 \cdot \left(x \cdot x\right)\right) - \color{blue}{x \cdot \left(1 + \left(x \cdot x\right) \cdot \left(-0.16666666666666666 + \left(x \cdot x\right) \cdot \left(0.008333333333333333 + x \cdot \left(x \cdot -0.0001984126984126984\right)\right)\right)\right)}\right) \]
  12. Final simplification96.9%

    \[\leadsto \varepsilon \cdot \left(\varepsilon \cdot \left(-0.5 + 0.25 \cdot \left(x \cdot x\right)\right) + x \cdot \left(-1 - \left(x \cdot x\right) \cdot \left(-0.16666666666666666 + \left(x \cdot x\right) \cdot \left(0.008333333333333333 + x \cdot \left(x \cdot -0.0001984126984126984\right)\right)\right)\right)\right) \]
  13. Add Preprocessing

Alternative 9: 98.0% accurate, 10.8× speedup?

\[\begin{array}{l} \\ \varepsilon \cdot \left(\varepsilon \cdot -0.5 + x \cdot \left(-1 + x \cdot \left(x \cdot 0.16666666666666666 + \varepsilon \cdot 0.25\right)\right)\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (*
  eps
  (+
   (* eps -0.5)
   (* x (+ -1.0 (* x (+ (* x 0.16666666666666666) (* eps 0.25))))))))
double code(double x, double eps) {
	return eps * ((eps * -0.5) + (x * (-1.0 + (x * ((x * 0.16666666666666666) + (eps * 0.25))))));
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = eps * ((eps * (-0.5d0)) + (x * ((-1.0d0) + (x * ((x * 0.16666666666666666d0) + (eps * 0.25d0))))))
end function
public static double code(double x, double eps) {
	return eps * ((eps * -0.5) + (x * (-1.0 + (x * ((x * 0.16666666666666666) + (eps * 0.25))))));
}
def code(x, eps):
	return eps * ((eps * -0.5) + (x * (-1.0 + (x * ((x * 0.16666666666666666) + (eps * 0.25))))))
function code(x, eps)
	return Float64(eps * Float64(Float64(eps * -0.5) + Float64(x * Float64(-1.0 + Float64(x * Float64(Float64(x * 0.16666666666666666) + Float64(eps * 0.25)))))))
end
function tmp = code(x, eps)
	tmp = eps * ((eps * -0.5) + (x * (-1.0 + (x * ((x * 0.16666666666666666) + (eps * 0.25))))));
end
code[x_, eps_] := N[(eps * N[(N[(eps * -0.5), $MachinePrecision] + N[(x * N[(-1.0 + N[(x * N[(N[(x * 0.16666666666666666), $MachinePrecision] + N[(eps * 0.25), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\varepsilon \cdot \left(\varepsilon \cdot -0.5 + x \cdot \left(-1 + x \cdot \left(x \cdot 0.16666666666666666 + \varepsilon \cdot 0.25\right)\right)\right)
\end{array}
Derivation
  1. Initial program 56.3%

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

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

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

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

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

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

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

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

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\frac{-1}{2}, \mathsf{cos.f64}\left(x\right)\right)\right), \sin x\right)\right) \]
    9. sin-lowering-sin.f6499.2%

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

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\varepsilon \cdot \left(-0.5 \cdot \cos x\right) - \sin x\right)} \]
  6. Taylor expanded in x around 0

    \[\leadsto \mathsf{*.f64}\left(\varepsilon, \color{blue}{\left(\frac{-1}{2} \cdot \varepsilon + x \cdot \left(x \cdot \left(\frac{1}{6} \cdot x + \frac{1}{4} \cdot \varepsilon\right) - 1\right)\right)}\right) \]
  7. Step-by-step derivation
    1. +-lowering-+.f64N/A

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\left(\varepsilon \cdot \frac{-1}{2}\right), \left(\color{blue}{x} \cdot \left(x \cdot \left(\frac{1}{6} \cdot x + \frac{1}{4} \cdot \varepsilon\right) - 1\right)\right)\right)\right) \]
    3. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{-1}{2}\right), \left(\color{blue}{x} \cdot \left(x \cdot \left(\frac{1}{6} \cdot x + \frac{1}{4} \cdot \varepsilon\right) - 1\right)\right)\right)\right) \]
    4. *-lowering-*.f64N/A

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

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{-1}{2}\right), \mathsf{*.f64}\left(x, \left(x \cdot \left(\frac{1}{6} \cdot x + \frac{1}{4} \cdot \varepsilon\right) + -1\right)\right)\right)\right) \]
    7. +-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{-1}{2}\right), \mathsf{*.f64}\left(x, \left(-1 + \color{blue}{x \cdot \left(\frac{1}{6} \cdot x + \frac{1}{4} \cdot \varepsilon\right)}\right)\right)\right)\right) \]
    8. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{-1}{2}\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(-1, \color{blue}{\left(x \cdot \left(\frac{1}{6} \cdot x + \frac{1}{4} \cdot \varepsilon\right)\right)}\right)\right)\right)\right) \]
    9. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{-1}{2}\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(-1, \mathsf{*.f64}\left(x, \color{blue}{\left(\frac{1}{6} \cdot x + \frac{1}{4} \cdot \varepsilon\right)}\right)\right)\right)\right)\right) \]
    10. +-lowering-+.f64N/A

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{-1}{2}\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(-1, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\left(x \cdot \frac{1}{6}\right), \left(\color{blue}{\frac{1}{4}} \cdot \varepsilon\right)\right)\right)\right)\right)\right)\right) \]
    12. *-lowering-*.f64N/A

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{-1}{2}\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(-1, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{1}{6}\right), \left(\varepsilon \cdot \color{blue}{\frac{1}{4}}\right)\right)\right)\right)\right)\right)\right) \]
    14. *-lowering-*.f6496.7%

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{+.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{-1}{2}\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(-1, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{1}{6}\right), \mathsf{*.f64}\left(\varepsilon, \color{blue}{\frac{1}{4}}\right)\right)\right)\right)\right)\right)\right) \]
  8. Simplified96.7%

    \[\leadsto \varepsilon \cdot \color{blue}{\left(\varepsilon \cdot -0.5 + x \cdot \left(-1 + x \cdot \left(x \cdot 0.16666666666666666 + \varepsilon \cdot 0.25\right)\right)\right)} \]
  9. Add Preprocessing

Alternative 10: 97.5% accurate, 18.6× speedup?

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

\\
x \cdot \left(\frac{\varepsilon \cdot \left(\varepsilon \cdot -0.5\right)}{x} - \varepsilon\right)
\end{array}
Derivation
  1. Initial program 56.3%

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

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

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

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

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

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

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

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

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\frac{-1}{2}, \mathsf{cos.f64}\left(x\right)\right)\right), \sin x\right)\right) \]
    9. sin-lowering-sin.f6499.2%

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

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\varepsilon \cdot \left(-0.5 \cdot \cos x\right) - \sin x\right)} \]
  6. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \left(\varepsilon \cdot \left(\frac{-1}{2} \cdot \cos x\right) - \sin x\right) \cdot \color{blue}{\varepsilon} \]
    2. --rgt-identityN/A

      \[\leadsto \left(\varepsilon \cdot \left(\frac{-1}{2} \cdot \cos x\right) - \sin x\right) \cdot \left(\varepsilon - \color{blue}{0}\right) \]
    3. flip--N/A

      \[\leadsto \left(\varepsilon \cdot \left(\frac{-1}{2} \cdot \cos x\right) - \sin x\right) \cdot \frac{\varepsilon \cdot \varepsilon - 0 \cdot 0}{\color{blue}{\varepsilon + 0}} \]
    4. metadata-evalN/A

      \[\leadsto \left(\varepsilon \cdot \left(\frac{-1}{2} \cdot \cos x\right) - \sin x\right) \cdot \frac{\varepsilon \cdot \varepsilon - 0}{\varepsilon + 0} \]
    5. --rgt-identityN/A

      \[\leadsto \left(\varepsilon \cdot \left(\frac{-1}{2} \cdot \cos x\right) - \sin x\right) \cdot \frac{\varepsilon \cdot \varepsilon}{\color{blue}{\varepsilon} + 0} \]
    6. +-rgt-identityN/A

      \[\leadsto \left(\varepsilon \cdot \left(\frac{-1}{2} \cdot \cos x\right) - \sin x\right) \cdot \frac{\varepsilon \cdot \varepsilon}{\varepsilon} \]
    7. associate-*r/N/A

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

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

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

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

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(\mathsf{\_.f64}\left(\left(\left(\frac{-1}{2} \cdot \cos x\right) \cdot \varepsilon\right), \sin x\right), \left(\varepsilon \cdot \varepsilon\right)\right), \varepsilon\right) \]
    12. associate-*l*N/A

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

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

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

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

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{*.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\mathsf{cos.f64}\left(x\right), \varepsilon\right)\right), \mathsf{sin.f64}\left(x\right)\right), \left(\varepsilon \cdot \varepsilon\right)\right), \varepsilon\right) \]
    17. *-lowering-*.f6484.2%

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{*.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(\mathsf{cos.f64}\left(x\right), \varepsilon\right)\right), \mathsf{sin.f64}\left(x\right)\right), \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right), \varepsilon\right) \]
  7. Applied egg-rr84.2%

    \[\leadsto \color{blue}{\frac{\left(-0.5 \cdot \left(\cos x \cdot \varepsilon\right) - \sin x\right) \cdot \left(\varepsilon \cdot \varepsilon\right)}{\varepsilon}} \]
  8. Taylor expanded in x around 0

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

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

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(\left(\frac{-1}{2} \cdot \varepsilon + \left(\mathsf{neg}\left(x\right)\right)\right), \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right), \varepsilon\right) \]
    3. unsub-negN/A

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

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(\mathsf{\_.f64}\left(\left(\frac{-1}{2} \cdot \varepsilon\right), x\right), \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right), \varepsilon\right) \]
    5. *-lowering-*.f6481.1%

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(\mathsf{\_.f64}\left(\mathsf{*.f64}\left(\frac{-1}{2}, \varepsilon\right), x\right), \mathsf{*.f64}\left(\varepsilon, \varepsilon\right)\right), \varepsilon\right) \]
  10. Simplified81.1%

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

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

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

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

      \[\leadsto \mathsf{*.f64}\left(x, \left(\frac{-1}{2} \cdot \frac{{\varepsilon}^{2}}{x} + \left(\mathsf{neg}\left(\varepsilon\right)\right)\right)\right) \]
    4. unsub-negN/A

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

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

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

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

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

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

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

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

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\varepsilon, \left(\varepsilon \cdot \frac{-1}{2}\right)\right), x\right), \varepsilon\right)\right) \]
    13. *-lowering-*.f6496.1%

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \frac{-1}{2}\right)\right), x\right), \varepsilon\right)\right) \]
  13. Simplified96.1%

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

Alternative 11: 97.5% accurate, 29.3× speedup?

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

\\
\varepsilon \cdot \left(\varepsilon \cdot -0.5 - x\right)
\end{array}
Derivation
  1. Initial program 56.3%

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

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

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

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

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

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

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

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

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\frac{-1}{2}, \mathsf{cos.f64}\left(x\right)\right)\right), \sin x\right)\right) \]
    9. sin-lowering-sin.f6499.2%

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

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\varepsilon \cdot \left(-0.5 \cdot \cos x\right) - \sin x\right)} \]
  6. Taylor expanded in x around 0

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

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

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

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

      \[\leadsto \left(-1 \cdot x\right) \cdot \varepsilon + \frac{-1}{2} \cdot {\varepsilon}^{2} \]
    5. unpow2N/A

      \[\leadsto \left(-1 \cdot x\right) \cdot \varepsilon + \frac{-1}{2} \cdot \left(\varepsilon \cdot \color{blue}{\varepsilon}\right) \]
    6. associate-*r*N/A

      \[\leadsto \left(-1 \cdot x\right) \cdot \varepsilon + \left(\frac{-1}{2} \cdot \varepsilon\right) \cdot \color{blue}{\varepsilon} \]
    7. distribute-rgt-outN/A

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

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

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \left(\frac{-1}{2} \cdot \varepsilon + \left(\mathsf{neg}\left(x\right)\right)\right)\right) \]
    11. unsub-negN/A

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

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\left(\varepsilon \cdot \frac{-1}{2}\right), x\right)\right) \]
    14. *-lowering-*.f6496.1%

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \frac{-1}{2}\right), x\right)\right) \]
  8. Simplified96.1%

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

Alternative 12: 78.2% 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 56.3%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  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. mul-1-negN/A

      \[\leadsto \mathsf{neg}\left(\varepsilon \cdot \sin x\right) \]
    2. neg-sub0N/A

      \[\leadsto 0 - \color{blue}{\varepsilon \cdot \sin x} \]
    3. --lowering--.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(0, \color{blue}{\left(\varepsilon \cdot \sin x\right)}\right) \]
    4. *-lowering-*.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(0, \mathsf{*.f64}\left(\varepsilon, \color{blue}{\sin x}\right)\right) \]
    5. sin-lowering-sin.f6480.9%

      \[\leadsto \mathsf{\_.f64}\left(0, \mathsf{*.f64}\left(\varepsilon, \mathsf{sin.f64}\left(x\right)\right)\right) \]
  5. Simplified80.9%

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

    \[\leadsto \mathsf{\_.f64}\left(0, \color{blue}{\left(\varepsilon \cdot x\right)}\right) \]
  7. Step-by-step derivation
    1. *-lowering-*.f6479.2%

      \[\leadsto \mathsf{\_.f64}\left(0, \mathsf{*.f64}\left(\varepsilon, \color{blue}{x}\right)\right) \]
  8. Simplified79.2%

    \[\leadsto 0 - \color{blue}{\varepsilon \cdot x} \]
  9. Final simplification79.2%

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

Alternative 13: 51.7% 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 56.3%

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

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

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

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

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

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

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

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

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\frac{-1}{2}, \mathsf{cos.f64}\left(x\right)\right)\right), \sin x\right)\right) \]
    9. sin-lowering-sin.f6499.2%

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

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\varepsilon \cdot \left(-0.5 \cdot \cos x\right) - \sin x\right)} \]
  6. Taylor expanded in x around 0

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

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \left(\varepsilon \cdot \color{blue}{\frac{-1}{2}}\right)\right) \]
    2. *-lowering-*.f6455.2%

      \[\leadsto \mathsf{*.f64}\left(\varepsilon, \mathsf{*.f64}\left(\varepsilon, \color{blue}{\frac{-1}{2}}\right)\right) \]
  8. Simplified55.2%

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

Alternative 14: 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 56.3%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  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.f6454.1%

      \[\leadsto \mathsf{+.f64}\left(\mathsf{cos.f64}\left(\varepsilon\right), -1\right) \]
  5. Simplified54.1%

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

    \[\leadsto \mathsf{+.f64}\left(\color{blue}{1}, -1\right) \]
  7. Step-by-step derivation
    1. Simplified54.1%

      \[\leadsto \color{blue}{1} + -1 \]
    2. Step-by-step derivation
      1. metadata-eval54.1%

        \[\leadsto 0 \]
    3. Applied egg-rr54.1%

      \[\leadsto \color{blue}{0} \]
    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 2024155 
    (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)))