2cos (problem 3.3.5)

Percentage Accurate: 38.3% → 99.4%
Time: 17.4s
Alternatives: 17
Speedup: 1.9×

Specification

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

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

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 17 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: 38.3% 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: 99.4% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sin \left(0.5 \cdot \varepsilon\right)\\ -2 \cdot \left(t_0 \cdot \mathsf{fma}\left(\cos x, t_0, \sin x \cdot \cos \left(0.5 \cdot \varepsilon\right)\right)\right) \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (sin (* 0.5 eps))))
   (* -2.0 (* t_0 (fma (cos x) t_0 (* (sin x) (cos (* 0.5 eps))))))))
double code(double x, double eps) {
	double t_0 = sin((0.5 * eps));
	return -2.0 * (t_0 * fma(cos(x), t_0, (sin(x) * cos((0.5 * eps)))));
}
function code(x, eps)
	t_0 = sin(Float64(0.5 * eps))
	return Float64(-2.0 * Float64(t_0 * fma(cos(x), t_0, Float64(sin(x) * cos(Float64(0.5 * eps))))))
end
code[x_, eps_] := Block[{t$95$0 = N[Sin[N[(0.5 * eps), $MachinePrecision]], $MachinePrecision]}, N[(-2.0 * N[(t$95$0 * N[(N[Cos[x], $MachinePrecision] * t$95$0 + N[(N[Sin[x], $MachinePrecision] * N[Cos[N[(0.5 * eps), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sin \left(0.5 \cdot \varepsilon\right)\\
-2 \cdot \left(t_0 \cdot \mathsf{fma}\left(\cos x, t_0, \sin x \cdot \cos \left(0.5 \cdot \varepsilon\right)\right)\right)
\end{array}
\end{array}
Derivation
  1. Initial program 41.7%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  2. Step-by-step derivation
    1. diff-cos50.1%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
    2. div-inv50.1%

      \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
    3. metadata-eval50.1%

      \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
    4. div-inv50.1%

      \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
    5. +-commutative50.1%

      \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(x + \left(x + \varepsilon\right)\right)} \cdot \frac{1}{2}\right)\right) \]
    6. metadata-eval50.1%

      \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
  3. Applied egg-rr50.1%

    \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right)} \]
  4. Step-by-step derivation
    1. *-commutative50.1%

      \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(0.5 \cdot \left(\left(x + \varepsilon\right) - x\right)\right)} \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right) \]
    2. +-commutative50.1%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\color{blue}{\left(\varepsilon + x\right)} - x\right)\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right) \]
    3. associate--l+80.9%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \color{blue}{\left(\varepsilon + \left(x - x\right)\right)}\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right) \]
    4. *-commutative80.9%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \color{blue}{\left(0.5 \cdot \left(x + \left(x + \varepsilon\right)\right)\right)}\right) \]
    5. associate-+r+80.9%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right)\right) \]
    6. +-commutative80.9%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \left(0.5 \cdot \color{blue}{\left(\varepsilon + \left(x + x\right)\right)}\right)\right) \]
  5. Simplified80.9%

    \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)\right)} \]
  6. Step-by-step derivation
    1. distribute-lft-in80.9%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \color{blue}{\left(0.5 \cdot \varepsilon + 0.5 \cdot \left(x + x\right)\right)}\right) \]
    2. sin-sum99.1%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \color{blue}{\left(\sin \left(0.5 \cdot \varepsilon\right) \cdot \cos \left(0.5 \cdot \left(x + x\right)\right) + \cos \left(0.5 \cdot \varepsilon\right) \cdot \sin \left(0.5 \cdot \left(x + x\right)\right)\right)}\right) \]
  7. Applied egg-rr99.1%

    \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \color{blue}{\left(\sin \left(0.5 \cdot \varepsilon\right) \cdot \cos \left(0.5 \cdot \left(x + x\right)\right) + \cos \left(0.5 \cdot \varepsilon\right) \cdot \sin \left(0.5 \cdot \left(x + x\right)\right)\right)}\right) \]
  8. Step-by-step derivation
    1. *-commutative99.1%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \left(\color{blue}{\cos \left(0.5 \cdot \left(x + x\right)\right) \cdot \sin \left(0.5 \cdot \varepsilon\right)} + \cos \left(0.5 \cdot \varepsilon\right) \cdot \sin \left(0.5 \cdot \left(x + x\right)\right)\right)\right) \]
    2. count-299.1%

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

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \left(\cos \color{blue}{\left(\left(2 \cdot x\right) \cdot 0.5\right)} \cdot \sin \left(0.5 \cdot \varepsilon\right) + \cos \left(0.5 \cdot \varepsilon\right) \cdot \sin \left(0.5 \cdot \left(x + x\right)\right)\right)\right) \]
    4. count-299.1%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \left(\cos \left(\color{blue}{\left(x + x\right)} \cdot 0.5\right) \cdot \sin \left(0.5 \cdot \varepsilon\right) + \cos \left(0.5 \cdot \varepsilon\right) \cdot \sin \left(0.5 \cdot \left(x + x\right)\right)\right)\right) \]
    5. count-299.1%

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

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \left(\cos \left(\left(x + x\right) \cdot 0.5\right) \cdot \sin \left(0.5 \cdot \varepsilon\right) + \cos \left(0.5 \cdot \varepsilon\right) \cdot \sin \color{blue}{\left(\left(2 \cdot x\right) \cdot 0.5\right)}\right)\right) \]
    7. count-299.1%

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

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

    \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \color{blue}{\mathsf{fma}\left(\cos x, \sin \left(0.5 \cdot \varepsilon\right), \sin x \cdot \cos \left(0.5 \cdot \varepsilon\right)\right)}\right) \]
  10. Taylor expanded in eps around inf 99.5%

    \[\leadsto -2 \cdot \color{blue}{\left(\left(\cos x \cdot \sin \left(0.5 \cdot \varepsilon\right) + \sin x \cdot \cos \left(0.5 \cdot \varepsilon\right)\right) \cdot \sin \left(0.5 \cdot \varepsilon\right)\right)} \]
  11. Step-by-step derivation
    1. fma-def99.6%

      \[\leadsto -2 \cdot \left(\color{blue}{\mathsf{fma}\left(\cos x, \sin \left(0.5 \cdot \varepsilon\right), \sin x \cdot \cos \left(0.5 \cdot \varepsilon\right)\right)} \cdot \sin \left(0.5 \cdot \varepsilon\right)\right) \]
    2. *-commutative99.6%

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

    \[\leadsto -2 \cdot \color{blue}{\left(\sin \left(0.5 \cdot \varepsilon\right) \cdot \mathsf{fma}\left(\cos x, \sin \left(0.5 \cdot \varepsilon\right), \sin x \cdot \cos \left(0.5 \cdot \varepsilon\right)\right)\right)} \]
  13. Final simplification99.6%

    \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \varepsilon\right) \cdot \mathsf{fma}\left(\cos x, \sin \left(0.5 \cdot \varepsilon\right), \sin x \cdot \cos \left(0.5 \cdot \varepsilon\right)\right)\right) \]

Alternative 2: 99.4% accurate, 0.4× speedup?

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

\\
\begin{array}{l}
t_0 := \sin \left(0.5 \cdot \varepsilon\right)\\
-2 \cdot \left(t_0 \cdot \left(\sin x \cdot \cos \left(0.5 \cdot \varepsilon\right) + t_0 \cdot \cos x\right)\right)
\end{array}
\end{array}
Derivation
  1. Initial program 41.7%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  2. Step-by-step derivation
    1. diff-cos50.1%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
    2. div-inv50.1%

      \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
    3. metadata-eval50.1%

      \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
    4. div-inv50.1%

      \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
    5. +-commutative50.1%

      \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(x + \left(x + \varepsilon\right)\right)} \cdot \frac{1}{2}\right)\right) \]
    6. metadata-eval50.1%

      \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
  3. Applied egg-rr50.1%

    \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right)} \]
  4. Step-by-step derivation
    1. *-commutative50.1%

      \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(0.5 \cdot \left(\left(x + \varepsilon\right) - x\right)\right)} \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right) \]
    2. +-commutative50.1%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\color{blue}{\left(\varepsilon + x\right)} - x\right)\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right) \]
    3. associate--l+80.9%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \color{blue}{\left(\varepsilon + \left(x - x\right)\right)}\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right) \]
    4. *-commutative80.9%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \color{blue}{\left(0.5 \cdot \left(x + \left(x + \varepsilon\right)\right)\right)}\right) \]
    5. associate-+r+80.9%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right)\right) \]
    6. +-commutative80.9%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \left(0.5 \cdot \color{blue}{\left(\varepsilon + \left(x + x\right)\right)}\right)\right) \]
  5. Simplified80.9%

    \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)\right)} \]
  6. Step-by-step derivation
    1. distribute-lft-in80.9%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \color{blue}{\left(0.5 \cdot \varepsilon + 0.5 \cdot \left(x + x\right)\right)}\right) \]
    2. sin-sum99.1%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \color{blue}{\left(\sin \left(0.5 \cdot \varepsilon\right) \cdot \cos \left(0.5 \cdot \left(x + x\right)\right) + \cos \left(0.5 \cdot \varepsilon\right) \cdot \sin \left(0.5 \cdot \left(x + x\right)\right)\right)}\right) \]
  7. Applied egg-rr99.1%

    \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \color{blue}{\left(\sin \left(0.5 \cdot \varepsilon\right) \cdot \cos \left(0.5 \cdot \left(x + x\right)\right) + \cos \left(0.5 \cdot \varepsilon\right) \cdot \sin \left(0.5 \cdot \left(x + x\right)\right)\right)}\right) \]
  8. Step-by-step derivation
    1. *-commutative99.1%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \left(\color{blue}{\cos \left(0.5 \cdot \left(x + x\right)\right) \cdot \sin \left(0.5 \cdot \varepsilon\right)} + \cos \left(0.5 \cdot \varepsilon\right) \cdot \sin \left(0.5 \cdot \left(x + x\right)\right)\right)\right) \]
    2. count-299.1%

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

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \left(\cos \color{blue}{\left(\left(2 \cdot x\right) \cdot 0.5\right)} \cdot \sin \left(0.5 \cdot \varepsilon\right) + \cos \left(0.5 \cdot \varepsilon\right) \cdot \sin \left(0.5 \cdot \left(x + x\right)\right)\right)\right) \]
    4. count-299.1%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \left(\cos \left(\color{blue}{\left(x + x\right)} \cdot 0.5\right) \cdot \sin \left(0.5 \cdot \varepsilon\right) + \cos \left(0.5 \cdot \varepsilon\right) \cdot \sin \left(0.5 \cdot \left(x + x\right)\right)\right)\right) \]
    5. count-299.1%

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

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \left(\cos \left(\left(x + x\right) \cdot 0.5\right) \cdot \sin \left(0.5 \cdot \varepsilon\right) + \cos \left(0.5 \cdot \varepsilon\right) \cdot \sin \color{blue}{\left(\left(2 \cdot x\right) \cdot 0.5\right)}\right)\right) \]
    7. count-299.1%

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

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

    \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \color{blue}{\mathsf{fma}\left(\cos x, \sin \left(0.5 \cdot \varepsilon\right), \sin x \cdot \cos \left(0.5 \cdot \varepsilon\right)\right)}\right) \]
  10. Taylor expanded in eps around inf 99.5%

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

    \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \varepsilon\right) \cdot \left(\sin x \cdot \cos \left(0.5 \cdot \varepsilon\right) + \sin \left(0.5 \cdot \varepsilon\right) \cdot \cos x\right)\right) \]

Alternative 3: 99.1% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.000165 \lor \neg \left(\varepsilon \leq 0.00016\right):\\ \;\;\;\;\cos x \cdot \cos \varepsilon - \left(\cos x + \sin x \cdot \sin \varepsilon\right)\\ \mathbf{else}:\\ \;\;\;\;-0.5 \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right) + \sin x \cdot \left(0.16666666666666666 \cdot {\varepsilon}^{3} - \varepsilon\right)\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (or (<= eps -0.000165) (not (<= eps 0.00016)))
   (- (* (cos x) (cos eps)) (+ (cos x) (* (sin x) (sin eps))))
   (+
    (* -0.5 (* eps (* eps (cos x))))
    (* (sin x) (- (* 0.16666666666666666 (pow eps 3.0)) eps)))))
double code(double x, double eps) {
	double tmp;
	if ((eps <= -0.000165) || !(eps <= 0.00016)) {
		tmp = (cos(x) * cos(eps)) - (cos(x) + (sin(x) * sin(eps)));
	} else {
		tmp = (-0.5 * (eps * (eps * cos(x)))) + (sin(x) * ((0.16666666666666666 * pow(eps, 3.0)) - eps));
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if ((eps <= (-0.000165d0)) .or. (.not. (eps <= 0.00016d0))) then
        tmp = (cos(x) * cos(eps)) - (cos(x) + (sin(x) * sin(eps)))
    else
        tmp = ((-0.5d0) * (eps * (eps * cos(x)))) + (sin(x) * ((0.16666666666666666d0 * (eps ** 3.0d0)) - eps))
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if ((eps <= -0.000165) || !(eps <= 0.00016)) {
		tmp = (Math.cos(x) * Math.cos(eps)) - (Math.cos(x) + (Math.sin(x) * Math.sin(eps)));
	} else {
		tmp = (-0.5 * (eps * (eps * Math.cos(x)))) + (Math.sin(x) * ((0.16666666666666666 * Math.pow(eps, 3.0)) - eps));
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if (eps <= -0.000165) or not (eps <= 0.00016):
		tmp = (math.cos(x) * math.cos(eps)) - (math.cos(x) + (math.sin(x) * math.sin(eps)))
	else:
		tmp = (-0.5 * (eps * (eps * math.cos(x)))) + (math.sin(x) * ((0.16666666666666666 * math.pow(eps, 3.0)) - eps))
	return tmp
function code(x, eps)
	tmp = 0.0
	if ((eps <= -0.000165) || !(eps <= 0.00016))
		tmp = Float64(Float64(cos(x) * cos(eps)) - Float64(cos(x) + Float64(sin(x) * sin(eps))));
	else
		tmp = Float64(Float64(-0.5 * Float64(eps * Float64(eps * cos(x)))) + Float64(sin(x) * Float64(Float64(0.16666666666666666 * (eps ^ 3.0)) - eps)));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if ((eps <= -0.000165) || ~((eps <= 0.00016)))
		tmp = (cos(x) * cos(eps)) - (cos(x) + (sin(x) * sin(eps)));
	else
		tmp = (-0.5 * (eps * (eps * cos(x)))) + (sin(x) * ((0.16666666666666666 * (eps ^ 3.0)) - eps));
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[Or[LessEqual[eps, -0.000165], N[Not[LessEqual[eps, 0.00016]], $MachinePrecision]], N[(N[(N[Cos[x], $MachinePrecision] * N[Cos[eps], $MachinePrecision]), $MachinePrecision] - N[(N[Cos[x], $MachinePrecision] + N[(N[Sin[x], $MachinePrecision] * N[Sin[eps], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(-0.5 * N[(eps * N[(eps * N[Cos[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[Sin[x], $MachinePrecision] * N[(N[(0.16666666666666666 * N[Power[eps, 3.0], $MachinePrecision]), $MachinePrecision] - eps), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\varepsilon \leq -0.000165 \lor \neg \left(\varepsilon \leq 0.00016\right):\\
\;\;\;\;\cos x \cdot \cos \varepsilon - \left(\cos x + \sin x \cdot \sin \varepsilon\right)\\

\mathbf{else}:\\
\;\;\;\;-0.5 \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right) + \sin x \cdot \left(0.16666666666666666 \cdot {\varepsilon}^{3} - \varepsilon\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if eps < -1.65e-4 or 1.60000000000000013e-4 < eps

    1. Initial program 58.2%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Step-by-step derivation
      1. sub-neg58.2%

        \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) + \left(-\cos x\right)} \]
      2. cos-sum98.5%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} + \left(-\cos x\right) \]
      3. associate-+l-98.4%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)} \]
      4. fma-neg98.5%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, -\left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)\right)} \]
    3. Applied egg-rr98.5%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, -\left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)\right)} \]
    4. Step-by-step derivation
      1. fma-neg98.4%

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

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

        \[\leadsto \cos \varepsilon \cdot \cos x - \left(\color{blue}{\sin \varepsilon \cdot \sin x} - \left(-\cos x\right)\right) \]
      4. fma-neg98.5%

        \[\leadsto \cos \varepsilon \cdot \cos x - \color{blue}{\mathsf{fma}\left(\sin \varepsilon, \sin x, -\left(-\cos x\right)\right)} \]
      5. remove-double-neg98.5%

        \[\leadsto \cos \varepsilon \cdot \cos x - \mathsf{fma}\left(\sin \varepsilon, \sin x, \color{blue}{\cos x}\right) \]
    5. Simplified98.5%

      \[\leadsto \color{blue}{\cos \varepsilon \cdot \cos x - \mathsf{fma}\left(\sin \varepsilon, \sin x, \cos x\right)} \]
    6. Taylor expanded in eps around inf 98.4%

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

    if -1.65e-4 < eps < 1.60000000000000013e-4

    1. Initial program 26.9%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Taylor expanded in eps around 0 99.8%

      \[\leadsto \color{blue}{0.16666666666666666 \cdot \left({\varepsilon}^{3} \cdot \sin x\right) + \left(-0.5 \cdot \left({\varepsilon}^{2} \cdot \cos x\right) + -1 \cdot \left(\varepsilon \cdot \sin x\right)\right)} \]
    3. Step-by-step derivation
      1. +-commutative99.8%

        \[\leadsto \color{blue}{\left(-0.5 \cdot \left({\varepsilon}^{2} \cdot \cos x\right) + -1 \cdot \left(\varepsilon \cdot \sin x\right)\right) + 0.16666666666666666 \cdot \left({\varepsilon}^{3} \cdot \sin x\right)} \]
      2. associate-+l+99.8%

        \[\leadsto \color{blue}{-0.5 \cdot \left({\varepsilon}^{2} \cdot \cos x\right) + \left(-1 \cdot \left(\varepsilon \cdot \sin x\right) + 0.16666666666666666 \cdot \left({\varepsilon}^{3} \cdot \sin x\right)\right)} \]
      3. unpow299.8%

        \[\leadsto -0.5 \cdot \left(\color{blue}{\left(\varepsilon \cdot \varepsilon\right)} \cdot \cos x\right) + \left(-1 \cdot \left(\varepsilon \cdot \sin x\right) + 0.16666666666666666 \cdot \left({\varepsilon}^{3} \cdot \sin x\right)\right) \]
      4. associate-*l*99.8%

        \[\leadsto -0.5 \cdot \color{blue}{\left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right)} + \left(-1 \cdot \left(\varepsilon \cdot \sin x\right) + 0.16666666666666666 \cdot \left({\varepsilon}^{3} \cdot \sin x\right)\right) \]
      5. associate-*r*99.8%

        \[\leadsto -0.5 \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right) + \left(\color{blue}{\left(-1 \cdot \varepsilon\right) \cdot \sin x} + 0.16666666666666666 \cdot \left({\varepsilon}^{3} \cdot \sin x\right)\right) \]
      6. associate-*r*99.8%

        \[\leadsto -0.5 \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right) + \left(\left(-1 \cdot \varepsilon\right) \cdot \sin x + \color{blue}{\left(0.16666666666666666 \cdot {\varepsilon}^{3}\right) \cdot \sin x}\right) \]
      7. distribute-rgt-out99.8%

        \[\leadsto -0.5 \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right) + \color{blue}{\sin x \cdot \left(-1 \cdot \varepsilon + 0.16666666666666666 \cdot {\varepsilon}^{3}\right)} \]
      8. mul-1-neg99.8%

        \[\leadsto -0.5 \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right) + \sin x \cdot \left(\color{blue}{\left(-\varepsilon\right)} + 0.16666666666666666 \cdot {\varepsilon}^{3}\right) \]
    4. Simplified99.8%

      \[\leadsto \color{blue}{-0.5 \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right) + \sin x \cdot \left(\left(-\varepsilon\right) + 0.16666666666666666 \cdot {\varepsilon}^{3}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.000165 \lor \neg \left(\varepsilon \leq 0.00016\right):\\ \;\;\;\;\cos x \cdot \cos \varepsilon - \left(\cos x + \sin x \cdot \sin \varepsilon\right)\\ \mathbf{else}:\\ \;\;\;\;-0.5 \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right) + \sin x \cdot \left(0.16666666666666666 \cdot {\varepsilon}^{3} - \varepsilon\right)\\ \end{array} \]

Alternative 4: 99.1% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos x \cdot \cos \varepsilon\\ t_1 := \sin x \cdot \sin \varepsilon\\ \mathbf{if}\;\varepsilon \leq -0.000155:\\ \;\;\;\;\left(t_0 - t_1\right) - \cos x\\ \mathbf{elif}\;\varepsilon \leq 0.000165:\\ \;\;\;\;-0.5 \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right) + \sin x \cdot \left(0.16666666666666666 \cdot {\varepsilon}^{3} - \varepsilon\right)\\ \mathbf{else}:\\ \;\;\;\;t_0 - \left(\cos x + t_1\right)\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (* (cos x) (cos eps))) (t_1 (* (sin x) (sin eps))))
   (if (<= eps -0.000155)
     (- (- t_0 t_1) (cos x))
     (if (<= eps 0.000165)
       (+
        (* -0.5 (* eps (* eps (cos x))))
        (* (sin x) (- (* 0.16666666666666666 (pow eps 3.0)) eps)))
       (- t_0 (+ (cos x) t_1))))))
double code(double x, double eps) {
	double t_0 = cos(x) * cos(eps);
	double t_1 = sin(x) * sin(eps);
	double tmp;
	if (eps <= -0.000155) {
		tmp = (t_0 - t_1) - cos(x);
	} else if (eps <= 0.000165) {
		tmp = (-0.5 * (eps * (eps * cos(x)))) + (sin(x) * ((0.16666666666666666 * pow(eps, 3.0)) - eps));
	} else {
		tmp = t_0 - (cos(x) + t_1);
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = cos(x) * cos(eps)
    t_1 = sin(x) * sin(eps)
    if (eps <= (-0.000155d0)) then
        tmp = (t_0 - t_1) - cos(x)
    else if (eps <= 0.000165d0) then
        tmp = ((-0.5d0) * (eps * (eps * cos(x)))) + (sin(x) * ((0.16666666666666666d0 * (eps ** 3.0d0)) - eps))
    else
        tmp = t_0 - (cos(x) + t_1)
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double t_0 = Math.cos(x) * Math.cos(eps);
	double t_1 = Math.sin(x) * Math.sin(eps);
	double tmp;
	if (eps <= -0.000155) {
		tmp = (t_0 - t_1) - Math.cos(x);
	} else if (eps <= 0.000165) {
		tmp = (-0.5 * (eps * (eps * Math.cos(x)))) + (Math.sin(x) * ((0.16666666666666666 * Math.pow(eps, 3.0)) - eps));
	} else {
		tmp = t_0 - (Math.cos(x) + t_1);
	}
	return tmp;
}
def code(x, eps):
	t_0 = math.cos(x) * math.cos(eps)
	t_1 = math.sin(x) * math.sin(eps)
	tmp = 0
	if eps <= -0.000155:
		tmp = (t_0 - t_1) - math.cos(x)
	elif eps <= 0.000165:
		tmp = (-0.5 * (eps * (eps * math.cos(x)))) + (math.sin(x) * ((0.16666666666666666 * math.pow(eps, 3.0)) - eps))
	else:
		tmp = t_0 - (math.cos(x) + t_1)
	return tmp
function code(x, eps)
	t_0 = Float64(cos(x) * cos(eps))
	t_1 = Float64(sin(x) * sin(eps))
	tmp = 0.0
	if (eps <= -0.000155)
		tmp = Float64(Float64(t_0 - t_1) - cos(x));
	elseif (eps <= 0.000165)
		tmp = Float64(Float64(-0.5 * Float64(eps * Float64(eps * cos(x)))) + Float64(sin(x) * Float64(Float64(0.16666666666666666 * (eps ^ 3.0)) - eps)));
	else
		tmp = Float64(t_0 - Float64(cos(x) + t_1));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	t_0 = cos(x) * cos(eps);
	t_1 = sin(x) * sin(eps);
	tmp = 0.0;
	if (eps <= -0.000155)
		tmp = (t_0 - t_1) - cos(x);
	elseif (eps <= 0.000165)
		tmp = (-0.5 * (eps * (eps * cos(x)))) + (sin(x) * ((0.16666666666666666 * (eps ^ 3.0)) - eps));
	else
		tmp = t_0 - (cos(x) + t_1);
	end
	tmp_2 = tmp;
end
code[x_, eps_] := Block[{t$95$0 = N[(N[Cos[x], $MachinePrecision] * N[Cos[eps], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[Sin[x], $MachinePrecision] * N[Sin[eps], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[eps, -0.000155], N[(N[(t$95$0 - t$95$1), $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision], If[LessEqual[eps, 0.000165], N[(N[(-0.5 * N[(eps * N[(eps * N[Cos[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[Sin[x], $MachinePrecision] * N[(N[(0.16666666666666666 * N[Power[eps, 3.0], $MachinePrecision]), $MachinePrecision] - eps), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(t$95$0 - N[(N[Cos[x], $MachinePrecision] + t$95$1), $MachinePrecision]), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos x \cdot \cos \varepsilon\\
t_1 := \sin x \cdot \sin \varepsilon\\
\mathbf{if}\;\varepsilon \leq -0.000155:\\
\;\;\;\;\left(t_0 - t_1\right) - \cos x\\

\mathbf{elif}\;\varepsilon \leq 0.000165:\\
\;\;\;\;-0.5 \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right) + \sin x \cdot \left(0.16666666666666666 \cdot {\varepsilon}^{3} - \varepsilon\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if eps < -1.55e-4

    1. Initial program 57.2%

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

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \]
    3. Applied egg-rr98.1%

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

    if -1.55e-4 < eps < 1.65e-4

    1. Initial program 26.9%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Taylor expanded in eps around 0 99.8%

      \[\leadsto \color{blue}{0.16666666666666666 \cdot \left({\varepsilon}^{3} \cdot \sin x\right) + \left(-0.5 \cdot \left({\varepsilon}^{2} \cdot \cos x\right) + -1 \cdot \left(\varepsilon \cdot \sin x\right)\right)} \]
    3. Step-by-step derivation
      1. +-commutative99.8%

        \[\leadsto \color{blue}{\left(-0.5 \cdot \left({\varepsilon}^{2} \cdot \cos x\right) + -1 \cdot \left(\varepsilon \cdot \sin x\right)\right) + 0.16666666666666666 \cdot \left({\varepsilon}^{3} \cdot \sin x\right)} \]
      2. associate-+l+99.8%

        \[\leadsto \color{blue}{-0.5 \cdot \left({\varepsilon}^{2} \cdot \cos x\right) + \left(-1 \cdot \left(\varepsilon \cdot \sin x\right) + 0.16666666666666666 \cdot \left({\varepsilon}^{3} \cdot \sin x\right)\right)} \]
      3. unpow299.8%

        \[\leadsto -0.5 \cdot \left(\color{blue}{\left(\varepsilon \cdot \varepsilon\right)} \cdot \cos x\right) + \left(-1 \cdot \left(\varepsilon \cdot \sin x\right) + 0.16666666666666666 \cdot \left({\varepsilon}^{3} \cdot \sin x\right)\right) \]
      4. associate-*l*99.8%

        \[\leadsto -0.5 \cdot \color{blue}{\left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right)} + \left(-1 \cdot \left(\varepsilon \cdot \sin x\right) + 0.16666666666666666 \cdot \left({\varepsilon}^{3} \cdot \sin x\right)\right) \]
      5. associate-*r*99.8%

        \[\leadsto -0.5 \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right) + \left(\color{blue}{\left(-1 \cdot \varepsilon\right) \cdot \sin x} + 0.16666666666666666 \cdot \left({\varepsilon}^{3} \cdot \sin x\right)\right) \]
      6. associate-*r*99.8%

        \[\leadsto -0.5 \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right) + \left(\left(-1 \cdot \varepsilon\right) \cdot \sin x + \color{blue}{\left(0.16666666666666666 \cdot {\varepsilon}^{3}\right) \cdot \sin x}\right) \]
      7. distribute-rgt-out99.8%

        \[\leadsto -0.5 \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right) + \color{blue}{\sin x \cdot \left(-1 \cdot \varepsilon + 0.16666666666666666 \cdot {\varepsilon}^{3}\right)} \]
      8. mul-1-neg99.8%

        \[\leadsto -0.5 \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right) + \sin x \cdot \left(\color{blue}{\left(-\varepsilon\right)} + 0.16666666666666666 \cdot {\varepsilon}^{3}\right) \]
    4. Simplified99.8%

      \[\leadsto \color{blue}{-0.5 \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right) + \sin x \cdot \left(\left(-\varepsilon\right) + 0.16666666666666666 \cdot {\varepsilon}^{3}\right)} \]

    if 1.65e-4 < eps

    1. Initial program 59.3%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Step-by-step derivation
      1. sub-neg59.3%

        \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) + \left(-\cos x\right)} \]
      2. cos-sum98.9%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} + \left(-\cos x\right) \]
      3. associate-+l-98.9%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)} \]
      4. fma-neg99.0%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, -\left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)\right)} \]
    3. Applied egg-rr99.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, -\left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)\right)} \]
    4. Step-by-step derivation
      1. fma-neg98.9%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)} \]
      2. *-commutative98.9%

        \[\leadsto \color{blue}{\cos \varepsilon \cdot \cos x} - \left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right) \]
      3. *-commutative98.9%

        \[\leadsto \cos \varepsilon \cdot \cos x - \left(\color{blue}{\sin \varepsilon \cdot \sin x} - \left(-\cos x\right)\right) \]
      4. fma-neg98.9%

        \[\leadsto \cos \varepsilon \cdot \cos x - \color{blue}{\mathsf{fma}\left(\sin \varepsilon, \sin x, -\left(-\cos x\right)\right)} \]
      5. remove-double-neg98.9%

        \[\leadsto \cos \varepsilon \cdot \cos x - \mathsf{fma}\left(\sin \varepsilon, \sin x, \color{blue}{\cos x}\right) \]
    5. Simplified98.9%

      \[\leadsto \color{blue}{\cos \varepsilon \cdot \cos x - \mathsf{fma}\left(\sin \varepsilon, \sin x, \cos x\right)} \]
    6. Taylor expanded in eps around inf 98.9%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.000155:\\ \;\;\;\;\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right) - \cos x\\ \mathbf{elif}\;\varepsilon \leq 0.000165:\\ \;\;\;\;-0.5 \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right) + \sin x \cdot \left(0.16666666666666666 \cdot {\varepsilon}^{3} - \varepsilon\right)\\ \mathbf{else}:\\ \;\;\;\;\cos x \cdot \cos \varepsilon - \left(\cos x + \sin x \cdot \sin \varepsilon\right)\\ \end{array} \]

Alternative 5: 75.2% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\cos \left(\varepsilon + x\right) - \cos x \leq -2 \cdot 10^{-13}:\\ \;\;\;\;\frac{\sin \varepsilon}{-1} \cdot \tan \left(\frac{\varepsilon}{2}\right)\\ \mathbf{else}:\\ \;\;\;\;-0.5 \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right) - \varepsilon \cdot \sin x\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (<= (- (cos (+ eps x)) (cos x)) -2e-13)
   (* (/ (sin eps) -1.0) (tan (/ eps 2.0)))
   (- (* -0.5 (* eps (* eps (cos x)))) (* eps (sin x)))))
double code(double x, double eps) {
	double tmp;
	if ((cos((eps + x)) - cos(x)) <= -2e-13) {
		tmp = (sin(eps) / -1.0) * tan((eps / 2.0));
	} else {
		tmp = (-0.5 * (eps * (eps * cos(x)))) - (eps * sin(x));
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if ((cos((eps + x)) - cos(x)) <= (-2d-13)) then
        tmp = (sin(eps) / (-1.0d0)) * tan((eps / 2.0d0))
    else
        tmp = ((-0.5d0) * (eps * (eps * cos(x)))) - (eps * sin(x))
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if ((Math.cos((eps + x)) - Math.cos(x)) <= -2e-13) {
		tmp = (Math.sin(eps) / -1.0) * Math.tan((eps / 2.0));
	} else {
		tmp = (-0.5 * (eps * (eps * Math.cos(x)))) - (eps * Math.sin(x));
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if (math.cos((eps + x)) - math.cos(x)) <= -2e-13:
		tmp = (math.sin(eps) / -1.0) * math.tan((eps / 2.0))
	else:
		tmp = (-0.5 * (eps * (eps * math.cos(x)))) - (eps * math.sin(x))
	return tmp
function code(x, eps)
	tmp = 0.0
	if (Float64(cos(Float64(eps + x)) - cos(x)) <= -2e-13)
		tmp = Float64(Float64(sin(eps) / -1.0) * tan(Float64(eps / 2.0)));
	else
		tmp = Float64(Float64(-0.5 * Float64(eps * Float64(eps * cos(x)))) - Float64(eps * sin(x)));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if ((cos((eps + x)) - cos(x)) <= -2e-13)
		tmp = (sin(eps) / -1.0) * tan((eps / 2.0));
	else
		tmp = (-0.5 * (eps * (eps * cos(x)))) - (eps * sin(x));
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[LessEqual[N[(N[Cos[N[(eps + x), $MachinePrecision]], $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision], -2e-13], N[(N[(N[Sin[eps], $MachinePrecision] / -1.0), $MachinePrecision] * N[Tan[N[(eps / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(N[(-0.5 * N[(eps * N[(eps * N[Cos[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(eps * N[Sin[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\cos \left(\varepsilon + x\right) - \cos x \leq -2 \cdot 10^{-13}:\\
\;\;\;\;\frac{\sin \varepsilon}{-1} \cdot \tan \left(\frac{\varepsilon}{2}\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (cos.f64 (+.f64 x eps)) (cos.f64 x)) < -2.0000000000000001e-13

    1. Initial program 84.7%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Taylor expanded in x around 0 84.8%

      \[\leadsto \color{blue}{\cos \varepsilon - 1} \]
    3. Step-by-step derivation
      1. add-log-exp84.4%

        \[\leadsto \color{blue}{\log \left(e^{\cos \varepsilon - 1}\right)} \]
      2. sub-neg84.4%

        \[\leadsto \log \left(e^{\color{blue}{\cos \varepsilon + \left(-1\right)}}\right) \]
      3. metadata-eval84.4%

        \[\leadsto \log \left(e^{\cos \varepsilon + \color{blue}{-1}}\right) \]
    4. Applied egg-rr84.4%

      \[\leadsto \color{blue}{\log \left(e^{\cos \varepsilon + -1}\right)} \]
    5. Step-by-step derivation
      1. add-log-exp84.8%

        \[\leadsto \color{blue}{\cos \varepsilon + -1} \]
      2. flip-+84.4%

        \[\leadsto \color{blue}{\frac{\cos \varepsilon \cdot \cos \varepsilon - -1 \cdot -1}{\cos \varepsilon - -1}} \]
      3. frac-2neg84.4%

        \[\leadsto \color{blue}{\frac{-\left(\cos \varepsilon \cdot \cos \varepsilon - -1 \cdot -1\right)}{-\left(\cos \varepsilon - -1\right)}} \]
      4. metadata-eval84.4%

        \[\leadsto \frac{-\left(\cos \varepsilon \cdot \cos \varepsilon - \color{blue}{1}\right)}{-\left(\cos \varepsilon - -1\right)} \]
      5. sub-1-cos85.8%

        \[\leadsto \frac{-\color{blue}{\left(-\sin \varepsilon \cdot \sin \varepsilon\right)}}{-\left(\cos \varepsilon - -1\right)} \]
      6. pow285.8%

        \[\leadsto \frac{-\left(-\color{blue}{{\sin \varepsilon}^{2}}\right)}{-\left(\cos \varepsilon - -1\right)} \]
    6. Applied egg-rr85.8%

      \[\leadsto \color{blue}{\frac{-\left(-{\sin \varepsilon}^{2}\right)}{-\left(\cos \varepsilon - -1\right)}} \]
    7. Step-by-step derivation
      1. remove-double-neg85.8%

        \[\leadsto \frac{\color{blue}{{\sin \varepsilon}^{2}}}{-\left(\cos \varepsilon - -1\right)} \]
      2. unpow285.8%

        \[\leadsto \frac{\color{blue}{\sin \varepsilon \cdot \sin \varepsilon}}{-\left(\cos \varepsilon - -1\right)} \]
      3. neg-mul-185.8%

        \[\leadsto \frac{\sin \varepsilon \cdot \sin \varepsilon}{\color{blue}{-1 \cdot \left(\cos \varepsilon - -1\right)}} \]
      4. times-frac85.8%

        \[\leadsto \color{blue}{\frac{\sin \varepsilon}{-1} \cdot \frac{\sin \varepsilon}{\cos \varepsilon - -1}} \]
      5. sub-neg85.8%

        \[\leadsto \frac{\sin \varepsilon}{-1} \cdot \frac{\sin \varepsilon}{\color{blue}{\cos \varepsilon + \left(--1\right)}} \]
      6. metadata-eval85.8%

        \[\leadsto \frac{\sin \varepsilon}{-1} \cdot \frac{\sin \varepsilon}{\cos \varepsilon + \color{blue}{1}} \]
      7. +-commutative85.8%

        \[\leadsto \frac{\sin \varepsilon}{-1} \cdot \frac{\sin \varepsilon}{\color{blue}{1 + \cos \varepsilon}} \]
      8. hang-0p-tan86.5%

        \[\leadsto \frac{\sin \varepsilon}{-1} \cdot \color{blue}{\tan \left(\frac{\varepsilon}{2}\right)} \]
    8. Simplified86.5%

      \[\leadsto \color{blue}{\frac{\sin \varepsilon}{-1} \cdot \tan \left(\frac{\varepsilon}{2}\right)} \]

    if -2.0000000000000001e-13 < (-.f64 (cos.f64 (+.f64 x eps)) (cos.f64 x))

    1. Initial program 22.2%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Taylor expanded in eps around 0 77.1%

      \[\leadsto \color{blue}{-0.5 \cdot \left({\varepsilon}^{2} \cdot \cos x\right) + -1 \cdot \left(\varepsilon \cdot \sin x\right)} \]
    3. Step-by-step derivation
      1. mul-1-neg77.1%

        \[\leadsto -0.5 \cdot \left({\varepsilon}^{2} \cdot \cos x\right) + \color{blue}{\left(-\varepsilon \cdot \sin x\right)} \]
      2. unsub-neg77.1%

        \[\leadsto \color{blue}{-0.5 \cdot \left({\varepsilon}^{2} \cdot \cos x\right) - \varepsilon \cdot \sin x} \]
      3. unpow277.1%

        \[\leadsto -0.5 \cdot \left(\color{blue}{\left(\varepsilon \cdot \varepsilon\right)} \cdot \cos x\right) - \varepsilon \cdot \sin x \]
      4. associate-*l*77.1%

        \[\leadsto -0.5 \cdot \color{blue}{\left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right)} - \varepsilon \cdot \sin x \]
    4. Simplified77.1%

      \[\leadsto \color{blue}{-0.5 \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right) - \varepsilon \cdot \sin x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification80.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\cos \left(\varepsilon + x\right) - \cos x \leq -2 \cdot 10^{-13}:\\ \;\;\;\;\frac{\sin \varepsilon}{-1} \cdot \tan \left(\frac{\varepsilon}{2}\right)\\ \mathbf{else}:\\ \;\;\;\;-0.5 \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot \cos x\right)\right) - \varepsilon \cdot \sin x\\ \end{array} \]

Alternative 6: 66.5% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\cos \left(\varepsilon + x\right) - \cos x \leq -2 \cdot 10^{-13}:\\ \;\;\;\;\cos x \cdot \cos \varepsilon + -1\\ \mathbf{else}:\\ \;\;\;\;\mathsf{expm1}\left(\sin x \cdot \left(-\varepsilon\right)\right)\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (<= (- (cos (+ eps x)) (cos x)) -2e-13)
   (+ (* (cos x) (cos eps)) -1.0)
   (expm1 (* (sin x) (- eps)))))
double code(double x, double eps) {
	double tmp;
	if ((cos((eps + x)) - cos(x)) <= -2e-13) {
		tmp = (cos(x) * cos(eps)) + -1.0;
	} else {
		tmp = expm1((sin(x) * -eps));
	}
	return tmp;
}
public static double code(double x, double eps) {
	double tmp;
	if ((Math.cos((eps + x)) - Math.cos(x)) <= -2e-13) {
		tmp = (Math.cos(x) * Math.cos(eps)) + -1.0;
	} else {
		tmp = Math.expm1((Math.sin(x) * -eps));
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if (math.cos((eps + x)) - math.cos(x)) <= -2e-13:
		tmp = (math.cos(x) * math.cos(eps)) + -1.0
	else:
		tmp = math.expm1((math.sin(x) * -eps))
	return tmp
function code(x, eps)
	tmp = 0.0
	if (Float64(cos(Float64(eps + x)) - cos(x)) <= -2e-13)
		tmp = Float64(Float64(cos(x) * cos(eps)) + -1.0);
	else
		tmp = expm1(Float64(sin(x) * Float64(-eps)));
	end
	return tmp
end
code[x_, eps_] := If[LessEqual[N[(N[Cos[N[(eps + x), $MachinePrecision]], $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision], -2e-13], N[(N[(N[Cos[x], $MachinePrecision] * N[Cos[eps], $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision], N[(Exp[N[(N[Sin[x], $MachinePrecision] * (-eps)), $MachinePrecision]] - 1), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\cos \left(\varepsilon + x\right) - \cos x \leq -2 \cdot 10^{-13}:\\
\;\;\;\;\cos x \cdot \cos \varepsilon + -1\\

\mathbf{else}:\\
\;\;\;\;\mathsf{expm1}\left(\sin x \cdot \left(-\varepsilon\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (cos.f64 (+.f64 x eps)) (cos.f64 x)) < -2.0000000000000001e-13

    1. Initial program 84.7%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Step-by-step derivation
      1. sub-neg84.7%

        \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) + \left(-\cos x\right)} \]
      2. cos-sum97.9%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} + \left(-\cos x\right) \]
      3. associate-+l-97.9%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)} \]
      4. fma-neg97.9%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, -\left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)\right)} \]
    3. Applied egg-rr97.9%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, -\left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)\right)} \]
    4. Step-by-step derivation
      1. fma-neg97.9%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)} \]
      2. *-commutative97.9%

        \[\leadsto \color{blue}{\cos \varepsilon \cdot \cos x} - \left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right) \]
      3. *-commutative97.9%

        \[\leadsto \cos \varepsilon \cdot \cos x - \left(\color{blue}{\sin \varepsilon \cdot \sin x} - \left(-\cos x\right)\right) \]
      4. fma-neg97.9%

        \[\leadsto \cos \varepsilon \cdot \cos x - \color{blue}{\mathsf{fma}\left(\sin \varepsilon, \sin x, -\left(-\cos x\right)\right)} \]
      5. remove-double-neg97.9%

        \[\leadsto \cos \varepsilon \cdot \cos x - \mathsf{fma}\left(\sin \varepsilon, \sin x, \color{blue}{\cos x}\right) \]
    5. Simplified97.9%

      \[\leadsto \color{blue}{\cos \varepsilon \cdot \cos x - \mathsf{fma}\left(\sin \varepsilon, \sin x, \cos x\right)} \]
    6. Taylor expanded in x around 0 84.9%

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

    if -2.0000000000000001e-13 < (-.f64 (cos.f64 (+.f64 x eps)) (cos.f64 x))

    1. Initial program 22.2%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Step-by-step derivation
      1. expm1-log1p-u22.2%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\cos \left(x + \varepsilon\right) - \cos x\right)\right)} \]
    3. Applied egg-rr22.2%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\cos \left(x + \varepsilon\right) - \cos x\right)\right)} \]
    4. Taylor expanded in eps around 0 65.0%

      \[\leadsto \mathsf{expm1}\left(\color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)}\right) \]
    5. Step-by-step derivation
      1. mul-1-neg65.0%

        \[\leadsto \mathsf{expm1}\left(\color{blue}{-\varepsilon \cdot \sin x}\right) \]
      2. *-commutative65.0%

        \[\leadsto \mathsf{expm1}\left(-\color{blue}{\sin x \cdot \varepsilon}\right) \]
      3. distribute-rgt-neg-in65.0%

        \[\leadsto \mathsf{expm1}\left(\color{blue}{\sin x \cdot \left(-\varepsilon\right)}\right) \]
    6. Simplified65.0%

      \[\leadsto \mathsf{expm1}\left(\color{blue}{\sin x \cdot \left(-\varepsilon\right)}\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification71.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\cos \left(\varepsilon + x\right) - \cos x \leq -2 \cdot 10^{-13}:\\ \;\;\;\;\cos x \cdot \cos \varepsilon + -1\\ \mathbf{else}:\\ \;\;\;\;\mathsf{expm1}\left(\sin x \cdot \left(-\varepsilon\right)\right)\\ \end{array} \]

Alternative 7: 66.5% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\cos \left(\varepsilon + x\right) - \cos x \leq -2 \cdot 10^{-13}:\\ \;\;\;\;\cos \varepsilon + -1\\ \mathbf{else}:\\ \;\;\;\;\mathsf{expm1}\left(\sin x \cdot \left(-\varepsilon\right)\right)\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (<= (- (cos (+ eps x)) (cos x)) -2e-13)
   (+ (cos eps) -1.0)
   (expm1 (* (sin x) (- eps)))))
double code(double x, double eps) {
	double tmp;
	if ((cos((eps + x)) - cos(x)) <= -2e-13) {
		tmp = cos(eps) + -1.0;
	} else {
		tmp = expm1((sin(x) * -eps));
	}
	return tmp;
}
public static double code(double x, double eps) {
	double tmp;
	if ((Math.cos((eps + x)) - Math.cos(x)) <= -2e-13) {
		tmp = Math.cos(eps) + -1.0;
	} else {
		tmp = Math.expm1((Math.sin(x) * -eps));
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if (math.cos((eps + x)) - math.cos(x)) <= -2e-13:
		tmp = math.cos(eps) + -1.0
	else:
		tmp = math.expm1((math.sin(x) * -eps))
	return tmp
function code(x, eps)
	tmp = 0.0
	if (Float64(cos(Float64(eps + x)) - cos(x)) <= -2e-13)
		tmp = Float64(cos(eps) + -1.0);
	else
		tmp = expm1(Float64(sin(x) * Float64(-eps)));
	end
	return tmp
end
code[x_, eps_] := If[LessEqual[N[(N[Cos[N[(eps + x), $MachinePrecision]], $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision], -2e-13], N[(N[Cos[eps], $MachinePrecision] + -1.0), $MachinePrecision], N[(Exp[N[(N[Sin[x], $MachinePrecision] * (-eps)), $MachinePrecision]] - 1), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\cos \left(\varepsilon + x\right) - \cos x \leq -2 \cdot 10^{-13}:\\
\;\;\;\;\cos \varepsilon + -1\\

\mathbf{else}:\\
\;\;\;\;\mathsf{expm1}\left(\sin x \cdot \left(-\varepsilon\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (cos.f64 (+.f64 x eps)) (cos.f64 x)) < -2.0000000000000001e-13

    1. Initial program 84.7%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Taylor expanded in x around 0 84.8%

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

    if -2.0000000000000001e-13 < (-.f64 (cos.f64 (+.f64 x eps)) (cos.f64 x))

    1. Initial program 22.2%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Step-by-step derivation
      1. expm1-log1p-u22.2%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\cos \left(x + \varepsilon\right) - \cos x\right)\right)} \]
    3. Applied egg-rr22.2%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\cos \left(x + \varepsilon\right) - \cos x\right)\right)} \]
    4. Taylor expanded in eps around 0 65.0%

      \[\leadsto \mathsf{expm1}\left(\color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)}\right) \]
    5. Step-by-step derivation
      1. mul-1-neg65.0%

        \[\leadsto \mathsf{expm1}\left(\color{blue}{-\varepsilon \cdot \sin x}\right) \]
      2. *-commutative65.0%

        \[\leadsto \mathsf{expm1}\left(-\color{blue}{\sin x \cdot \varepsilon}\right) \]
      3. distribute-rgt-neg-in65.0%

        \[\leadsto \mathsf{expm1}\left(\color{blue}{\sin x \cdot \left(-\varepsilon\right)}\right) \]
    6. Simplified65.0%

      \[\leadsto \mathsf{expm1}\left(\color{blue}{\sin x \cdot \left(-\varepsilon\right)}\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification71.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\cos \left(\varepsilon + x\right) - \cos x \leq -2 \cdot 10^{-13}:\\ \;\;\;\;\cos \varepsilon + -1\\ \mathbf{else}:\\ \;\;\;\;\mathsf{expm1}\left(\sin x \cdot \left(-\varepsilon\right)\right)\\ \end{array} \]

Alternative 8: 69.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -0.27 \lor \neg \left(x \leq 1.35 \cdot 10^{-69}\right):\\ \;\;\;\;-2 \cdot \left(\sin x \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\sin \varepsilon}{-1} \cdot \tan \left(\frac{\varepsilon}{2}\right)\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (or (<= x -0.27) (not (<= x 1.35e-69)))
   (* -2.0 (* (sin x) (sin (* 0.5 (+ eps (- x x))))))
   (* (/ (sin eps) -1.0) (tan (/ eps 2.0)))))
double code(double x, double eps) {
	double tmp;
	if ((x <= -0.27) || !(x <= 1.35e-69)) {
		tmp = -2.0 * (sin(x) * sin((0.5 * (eps + (x - x)))));
	} else {
		tmp = (sin(eps) / -1.0) * tan((eps / 2.0));
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if ((x <= (-0.27d0)) .or. (.not. (x <= 1.35d-69))) then
        tmp = (-2.0d0) * (sin(x) * sin((0.5d0 * (eps + (x - x)))))
    else
        tmp = (sin(eps) / (-1.0d0)) * tan((eps / 2.0d0))
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if ((x <= -0.27) || !(x <= 1.35e-69)) {
		tmp = -2.0 * (Math.sin(x) * Math.sin((0.5 * (eps + (x - x)))));
	} else {
		tmp = (Math.sin(eps) / -1.0) * Math.tan((eps / 2.0));
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if (x <= -0.27) or not (x <= 1.35e-69):
		tmp = -2.0 * (math.sin(x) * math.sin((0.5 * (eps + (x - x)))))
	else:
		tmp = (math.sin(eps) / -1.0) * math.tan((eps / 2.0))
	return tmp
function code(x, eps)
	tmp = 0.0
	if ((x <= -0.27) || !(x <= 1.35e-69))
		tmp = Float64(-2.0 * Float64(sin(x) * sin(Float64(0.5 * Float64(eps + Float64(x - x))))));
	else
		tmp = Float64(Float64(sin(eps) / -1.0) * tan(Float64(eps / 2.0)));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if ((x <= -0.27) || ~((x <= 1.35e-69)))
		tmp = -2.0 * (sin(x) * sin((0.5 * (eps + (x - x)))));
	else
		tmp = (sin(eps) / -1.0) * tan((eps / 2.0));
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[Or[LessEqual[x, -0.27], N[Not[LessEqual[x, 1.35e-69]], $MachinePrecision]], N[(-2.0 * N[(N[Sin[x], $MachinePrecision] * N[Sin[N[(0.5 * N[(eps + N[(x - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[Sin[eps], $MachinePrecision] / -1.0), $MachinePrecision] * N[Tan[N[(eps / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -0.27 \lor \neg \left(x \leq 1.35 \cdot 10^{-69}\right):\\
\;\;\;\;-2 \cdot \left(\sin x \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right)\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{\sin \varepsilon}{-1} \cdot \tan \left(\frac{\varepsilon}{2}\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -0.27000000000000002 or 1.3499999999999999e-69 < x

    1. Initial program 11.3%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Step-by-step derivation
      1. diff-cos11.2%

        \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      2. div-inv11.2%

        \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      3. metadata-eval11.2%

        \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      4. div-inv11.2%

        \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
      5. +-commutative11.2%

        \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(x + \left(x + \varepsilon\right)\right)} \cdot \frac{1}{2}\right)\right) \]
      6. metadata-eval11.2%

        \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
    3. Applied egg-rr11.2%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right)} \]
    4. Step-by-step derivation
      1. *-commutative11.2%

        \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(0.5 \cdot \left(\left(x + \varepsilon\right) - x\right)\right)} \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right) \]
      2. +-commutative11.2%

        \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\color{blue}{\left(\varepsilon + x\right)} - x\right)\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right) \]
      3. associate--l+64.7%

        \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \color{blue}{\left(\varepsilon + \left(x - x\right)\right)}\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right) \]
      4. *-commutative64.7%

        \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \color{blue}{\left(0.5 \cdot \left(x + \left(x + \varepsilon\right)\right)\right)}\right) \]
      5. associate-+r+64.7%

        \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right)\right) \]
      6. +-commutative64.7%

        \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \left(0.5 \cdot \color{blue}{\left(\varepsilon + \left(x + x\right)\right)}\right)\right) \]
    5. Simplified64.7%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)\right)} \]
    6. Taylor expanded in eps around 0 60.3%

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

    if -0.27000000000000002 < x < 1.3499999999999999e-69

    1. Initial program 75.6%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Taylor expanded in x around 0 75.6%

      \[\leadsto \color{blue}{\cos \varepsilon - 1} \]
    3. Step-by-step derivation
      1. add-log-exp75.4%

        \[\leadsto \color{blue}{\log \left(e^{\cos \varepsilon - 1}\right)} \]
      2. sub-neg75.4%

        \[\leadsto \log \left(e^{\color{blue}{\cos \varepsilon + \left(-1\right)}}\right) \]
      3. metadata-eval75.4%

        \[\leadsto \log \left(e^{\cos \varepsilon + \color{blue}{-1}}\right) \]
    4. Applied egg-rr75.4%

      \[\leadsto \color{blue}{\log \left(e^{\cos \varepsilon + -1}\right)} \]
    5. Step-by-step derivation
      1. add-log-exp75.6%

        \[\leadsto \color{blue}{\cos \varepsilon + -1} \]
      2. flip-+75.3%

        \[\leadsto \color{blue}{\frac{\cos \varepsilon \cdot \cos \varepsilon - -1 \cdot -1}{\cos \varepsilon - -1}} \]
      3. frac-2neg75.3%

        \[\leadsto \color{blue}{\frac{-\left(\cos \varepsilon \cdot \cos \varepsilon - -1 \cdot -1\right)}{-\left(\cos \varepsilon - -1\right)}} \]
      4. metadata-eval75.3%

        \[\leadsto \frac{-\left(\cos \varepsilon \cdot \cos \varepsilon - \color{blue}{1}\right)}{-\left(\cos \varepsilon - -1\right)} \]
      5. sub-1-cos92.9%

        \[\leadsto \frac{-\color{blue}{\left(-\sin \varepsilon \cdot \sin \varepsilon\right)}}{-\left(\cos \varepsilon - -1\right)} \]
      6. pow292.9%

        \[\leadsto \frac{-\left(-\color{blue}{{\sin \varepsilon}^{2}}\right)}{-\left(\cos \varepsilon - -1\right)} \]
    6. Applied egg-rr92.9%

      \[\leadsto \color{blue}{\frac{-\left(-{\sin \varepsilon}^{2}\right)}{-\left(\cos \varepsilon - -1\right)}} \]
    7. Step-by-step derivation
      1. remove-double-neg92.9%

        \[\leadsto \frac{\color{blue}{{\sin \varepsilon}^{2}}}{-\left(\cos \varepsilon - -1\right)} \]
      2. unpow292.9%

        \[\leadsto \frac{\color{blue}{\sin \varepsilon \cdot \sin \varepsilon}}{-\left(\cos \varepsilon - -1\right)} \]
      3. neg-mul-192.9%

        \[\leadsto \frac{\sin \varepsilon \cdot \sin \varepsilon}{\color{blue}{-1 \cdot \left(\cos \varepsilon - -1\right)}} \]
      4. times-frac92.9%

        \[\leadsto \color{blue}{\frac{\sin \varepsilon}{-1} \cdot \frac{\sin \varepsilon}{\cos \varepsilon - -1}} \]
      5. sub-neg92.9%

        \[\leadsto \frac{\sin \varepsilon}{-1} \cdot \frac{\sin \varepsilon}{\color{blue}{\cos \varepsilon + \left(--1\right)}} \]
      6. metadata-eval92.9%

        \[\leadsto \frac{\sin \varepsilon}{-1} \cdot \frac{\sin \varepsilon}{\cos \varepsilon + \color{blue}{1}} \]
      7. +-commutative92.9%

        \[\leadsto \frac{\sin \varepsilon}{-1} \cdot \frac{\sin \varepsilon}{\color{blue}{1 + \cos \varepsilon}} \]
      8. hang-0p-tan93.4%

        \[\leadsto \frac{\sin \varepsilon}{-1} \cdot \color{blue}{\tan \left(\frac{\varepsilon}{2}\right)} \]
    8. Simplified93.4%

      \[\leadsto \color{blue}{\frac{\sin \varepsilon}{-1} \cdot \tan \left(\frac{\varepsilon}{2}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification76.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -0.27 \lor \neg \left(x \leq 1.35 \cdot 10^{-69}\right):\\ \;\;\;\;-2 \cdot \left(\sin x \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\sin \varepsilon}{-1} \cdot \tan \left(\frac{\varepsilon}{2}\right)\\ \end{array} \]

Alternative 9: 76.2% accurate, 1.0× speedup?

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

\\
-2 \cdot \left(\sin \left(0.5 \cdot \varepsilon\right) \cdot \sin \left(0.5 \cdot \left(\varepsilon - -2 \cdot x\right)\right)\right)
\end{array}
Derivation
  1. Initial program 41.7%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  2. Step-by-step derivation
    1. diff-cos50.1%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
    2. div-inv50.1%

      \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
    3. metadata-eval50.1%

      \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
    4. div-inv50.1%

      \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
    5. +-commutative50.1%

      \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(x + \left(x + \varepsilon\right)\right)} \cdot \frac{1}{2}\right)\right) \]
    6. metadata-eval50.1%

      \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
  3. Applied egg-rr50.1%

    \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right)} \]
  4. Step-by-step derivation
    1. *-commutative50.1%

      \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(0.5 \cdot \left(\left(x + \varepsilon\right) - x\right)\right)} \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right) \]
    2. +-commutative50.1%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\color{blue}{\left(\varepsilon + x\right)} - x\right)\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right) \]
    3. associate--l+80.9%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \color{blue}{\left(\varepsilon + \left(x - x\right)\right)}\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right) \]
    4. *-commutative80.9%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \color{blue}{\left(0.5 \cdot \left(x + \left(x + \varepsilon\right)\right)\right)}\right) \]
    5. associate-+r+80.9%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right)\right) \]
    6. +-commutative80.9%

      \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \left(0.5 \cdot \color{blue}{\left(\varepsilon + \left(x + x\right)\right)}\right)\right) \]
  5. Simplified80.9%

    \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)\right)} \]
  6. Taylor expanded in x around -inf 80.9%

    \[\leadsto -2 \cdot \color{blue}{\left(\sin \left(0.5 \cdot \left(\varepsilon - -2 \cdot x\right)\right) \cdot \sin \left(0.5 \cdot \varepsilon\right)\right)} \]
  7. Final simplification80.9%

    \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \varepsilon\right) \cdot \sin \left(0.5 \cdot \left(\varepsilon - -2 \cdot x\right)\right)\right) \]

Alternative 10: 68.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -0.27 \lor \neg \left(x \leq 5.5 \cdot 10^{-85}\right):\\ \;\;\;\;\mathsf{expm1}\left(\sin x \cdot \left(-\varepsilon\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\sin \varepsilon}{-1} \cdot \tan \left(\frac{\varepsilon}{2}\right)\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (or (<= x -0.27) (not (<= x 5.5e-85)))
   (expm1 (* (sin x) (- eps)))
   (* (/ (sin eps) -1.0) (tan (/ eps 2.0)))))
double code(double x, double eps) {
	double tmp;
	if ((x <= -0.27) || !(x <= 5.5e-85)) {
		tmp = expm1((sin(x) * -eps));
	} else {
		tmp = (sin(eps) / -1.0) * tan((eps / 2.0));
	}
	return tmp;
}
public static double code(double x, double eps) {
	double tmp;
	if ((x <= -0.27) || !(x <= 5.5e-85)) {
		tmp = Math.expm1((Math.sin(x) * -eps));
	} else {
		tmp = (Math.sin(eps) / -1.0) * Math.tan((eps / 2.0));
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if (x <= -0.27) or not (x <= 5.5e-85):
		tmp = math.expm1((math.sin(x) * -eps))
	else:
		tmp = (math.sin(eps) / -1.0) * math.tan((eps / 2.0))
	return tmp
function code(x, eps)
	tmp = 0.0
	if ((x <= -0.27) || !(x <= 5.5e-85))
		tmp = expm1(Float64(sin(x) * Float64(-eps)));
	else
		tmp = Float64(Float64(sin(eps) / -1.0) * tan(Float64(eps / 2.0)));
	end
	return tmp
end
code[x_, eps_] := If[Or[LessEqual[x, -0.27], N[Not[LessEqual[x, 5.5e-85]], $MachinePrecision]], N[(Exp[N[(N[Sin[x], $MachinePrecision] * (-eps)), $MachinePrecision]] - 1), $MachinePrecision], N[(N[(N[Sin[eps], $MachinePrecision] / -1.0), $MachinePrecision] * N[Tan[N[(eps / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -0.27 \lor \neg \left(x \leq 5.5 \cdot 10^{-85}\right):\\
\;\;\;\;\mathsf{expm1}\left(\sin x \cdot \left(-\varepsilon\right)\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{\sin \varepsilon}{-1} \cdot \tan \left(\frac{\varepsilon}{2}\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -0.27000000000000002 or 5.4999999999999997e-85 < x

    1. Initial program 12.6%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Step-by-step derivation
      1. expm1-log1p-u9.1%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\cos \left(x + \varepsilon\right) - \cos x\right)\right)} \]
    3. Applied egg-rr9.1%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\cos \left(x + \varepsilon\right) - \cos x\right)\right)} \]
    4. Taylor expanded in eps around 0 58.6%

      \[\leadsto \mathsf{expm1}\left(\color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)}\right) \]
    5. Step-by-step derivation
      1. mul-1-neg58.6%

        \[\leadsto \mathsf{expm1}\left(\color{blue}{-\varepsilon \cdot \sin x}\right) \]
      2. *-commutative58.6%

        \[\leadsto \mathsf{expm1}\left(-\color{blue}{\sin x \cdot \varepsilon}\right) \]
      3. distribute-rgt-neg-in58.6%

        \[\leadsto \mathsf{expm1}\left(\color{blue}{\sin x \cdot \left(-\varepsilon\right)}\right) \]
    6. Simplified58.6%

      \[\leadsto \mathsf{expm1}\left(\color{blue}{\sin x \cdot \left(-\varepsilon\right)}\right) \]

    if -0.27000000000000002 < x < 5.4999999999999997e-85

    1. Initial program 75.8%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Taylor expanded in x around 0 75.8%

      \[\leadsto \color{blue}{\cos \varepsilon - 1} \]
    3. Step-by-step derivation
      1. add-log-exp75.6%

        \[\leadsto \color{blue}{\log \left(e^{\cos \varepsilon - 1}\right)} \]
      2. sub-neg75.6%

        \[\leadsto \log \left(e^{\color{blue}{\cos \varepsilon + \left(-1\right)}}\right) \]
      3. metadata-eval75.6%

        \[\leadsto \log \left(e^{\cos \varepsilon + \color{blue}{-1}}\right) \]
    4. Applied egg-rr75.6%

      \[\leadsto \color{blue}{\log \left(e^{\cos \varepsilon + -1}\right)} \]
    5. Step-by-step derivation
      1. add-log-exp75.8%

        \[\leadsto \color{blue}{\cos \varepsilon + -1} \]
      2. flip-+75.5%

        \[\leadsto \color{blue}{\frac{\cos \varepsilon \cdot \cos \varepsilon - -1 \cdot -1}{\cos \varepsilon - -1}} \]
      3. frac-2neg75.5%

        \[\leadsto \color{blue}{\frac{-\left(\cos \varepsilon \cdot \cos \varepsilon - -1 \cdot -1\right)}{-\left(\cos \varepsilon - -1\right)}} \]
      4. metadata-eval75.5%

        \[\leadsto \frac{-\left(\cos \varepsilon \cdot \cos \varepsilon - \color{blue}{1}\right)}{-\left(\cos \varepsilon - -1\right)} \]
      5. sub-1-cos93.5%

        \[\leadsto \frac{-\color{blue}{\left(-\sin \varepsilon \cdot \sin \varepsilon\right)}}{-\left(\cos \varepsilon - -1\right)} \]
      6. pow293.5%

        \[\leadsto \frac{-\left(-\color{blue}{{\sin \varepsilon}^{2}}\right)}{-\left(\cos \varepsilon - -1\right)} \]
    6. Applied egg-rr93.5%

      \[\leadsto \color{blue}{\frac{-\left(-{\sin \varepsilon}^{2}\right)}{-\left(\cos \varepsilon - -1\right)}} \]
    7. Step-by-step derivation
      1. remove-double-neg93.5%

        \[\leadsto \frac{\color{blue}{{\sin \varepsilon}^{2}}}{-\left(\cos \varepsilon - -1\right)} \]
      2. unpow293.5%

        \[\leadsto \frac{\color{blue}{\sin \varepsilon \cdot \sin \varepsilon}}{-\left(\cos \varepsilon - -1\right)} \]
      3. neg-mul-193.5%

        \[\leadsto \frac{\sin \varepsilon \cdot \sin \varepsilon}{\color{blue}{-1 \cdot \left(\cos \varepsilon - -1\right)}} \]
      4. times-frac93.5%

        \[\leadsto \color{blue}{\frac{\sin \varepsilon}{-1} \cdot \frac{\sin \varepsilon}{\cos \varepsilon - -1}} \]
      5. sub-neg93.5%

        \[\leadsto \frac{\sin \varepsilon}{-1} \cdot \frac{\sin \varepsilon}{\color{blue}{\cos \varepsilon + \left(--1\right)}} \]
      6. metadata-eval93.5%

        \[\leadsto \frac{\sin \varepsilon}{-1} \cdot \frac{\sin \varepsilon}{\cos \varepsilon + \color{blue}{1}} \]
      7. +-commutative93.5%

        \[\leadsto \frac{\sin \varepsilon}{-1} \cdot \frac{\sin \varepsilon}{\color{blue}{1 + \cos \varepsilon}} \]
      8. hang-0p-tan94.0%

        \[\leadsto \frac{\sin \varepsilon}{-1} \cdot \color{blue}{\tan \left(\frac{\varepsilon}{2}\right)} \]
    8. Simplified94.0%

      \[\leadsto \color{blue}{\frac{\sin \varepsilon}{-1} \cdot \tan \left(\frac{\varepsilon}{2}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification74.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -0.27 \lor \neg \left(x \leq 5.5 \cdot 10^{-85}\right):\\ \;\;\;\;\mathsf{expm1}\left(\sin x \cdot \left(-\varepsilon\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\sin \varepsilon}{-1} \cdot \tan \left(\frac{\varepsilon}{2}\right)\\ \end{array} \]

Alternative 11: 67.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -0.27 \lor \neg \left(x \leq 5.5 \cdot 10^{-85}\right):\\ \;\;\;\;\mathsf{expm1}\left(\sin x \cdot \left(-\varepsilon\right)\right)\\ \mathbf{else}:\\ \;\;\;\;-2 \cdot {\sin \left(0.5 \cdot \varepsilon\right)}^{2}\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (or (<= x -0.27) (not (<= x 5.5e-85)))
   (expm1 (* (sin x) (- eps)))
   (* -2.0 (pow (sin (* 0.5 eps)) 2.0))))
double code(double x, double eps) {
	double tmp;
	if ((x <= -0.27) || !(x <= 5.5e-85)) {
		tmp = expm1((sin(x) * -eps));
	} else {
		tmp = -2.0 * pow(sin((0.5 * eps)), 2.0);
	}
	return tmp;
}
public static double code(double x, double eps) {
	double tmp;
	if ((x <= -0.27) || !(x <= 5.5e-85)) {
		tmp = Math.expm1((Math.sin(x) * -eps));
	} else {
		tmp = -2.0 * Math.pow(Math.sin((0.5 * eps)), 2.0);
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if (x <= -0.27) or not (x <= 5.5e-85):
		tmp = math.expm1((math.sin(x) * -eps))
	else:
		tmp = -2.0 * math.pow(math.sin((0.5 * eps)), 2.0)
	return tmp
function code(x, eps)
	tmp = 0.0
	if ((x <= -0.27) || !(x <= 5.5e-85))
		tmp = expm1(Float64(sin(x) * Float64(-eps)));
	else
		tmp = Float64(-2.0 * (sin(Float64(0.5 * eps)) ^ 2.0));
	end
	return tmp
end
code[x_, eps_] := If[Or[LessEqual[x, -0.27], N[Not[LessEqual[x, 5.5e-85]], $MachinePrecision]], N[(Exp[N[(N[Sin[x], $MachinePrecision] * (-eps)), $MachinePrecision]] - 1), $MachinePrecision], N[(-2.0 * N[Power[N[Sin[N[(0.5 * eps), $MachinePrecision]], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -0.27 \lor \neg \left(x \leq 5.5 \cdot 10^{-85}\right):\\
\;\;\;\;\mathsf{expm1}\left(\sin x \cdot \left(-\varepsilon\right)\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -0.27000000000000002 or 5.4999999999999997e-85 < x

    1. Initial program 12.6%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Step-by-step derivation
      1. expm1-log1p-u9.1%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\cos \left(x + \varepsilon\right) - \cos x\right)\right)} \]
    3. Applied egg-rr9.1%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\cos \left(x + \varepsilon\right) - \cos x\right)\right)} \]
    4. Taylor expanded in eps around 0 58.6%

      \[\leadsto \mathsf{expm1}\left(\color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)}\right) \]
    5. Step-by-step derivation
      1. mul-1-neg58.6%

        \[\leadsto \mathsf{expm1}\left(\color{blue}{-\varepsilon \cdot \sin x}\right) \]
      2. *-commutative58.6%

        \[\leadsto \mathsf{expm1}\left(-\color{blue}{\sin x \cdot \varepsilon}\right) \]
      3. distribute-rgt-neg-in58.6%

        \[\leadsto \mathsf{expm1}\left(\color{blue}{\sin x \cdot \left(-\varepsilon\right)}\right) \]
    6. Simplified58.6%

      \[\leadsto \mathsf{expm1}\left(\color{blue}{\sin x \cdot \left(-\varepsilon\right)}\right) \]

    if -0.27000000000000002 < x < 5.4999999999999997e-85

    1. Initial program 75.8%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Step-by-step derivation
      1. diff-cos94.2%

        \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      2. div-inv94.2%

        \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      3. metadata-eval94.2%

        \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      4. div-inv94.2%

        \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
      5. +-commutative94.2%

        \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(x + \left(x + \varepsilon\right)\right)} \cdot \frac{1}{2}\right)\right) \]
      6. metadata-eval94.2%

        \[\leadsto -2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
    3. Applied egg-rr94.2%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(\left(x + \varepsilon\right) - x\right) \cdot 0.5\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right)} \]
    4. Step-by-step derivation
      1. *-commutative94.2%

        \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(0.5 \cdot \left(\left(x + \varepsilon\right) - x\right)\right)} \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right) \]
      2. +-commutative94.2%

        \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\color{blue}{\left(\varepsilon + x\right)} - x\right)\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right) \]
      3. associate--l+99.0%

        \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \color{blue}{\left(\varepsilon + \left(x - x\right)\right)}\right) \cdot \sin \left(\left(x + \left(x + \varepsilon\right)\right) \cdot 0.5\right)\right) \]
      4. *-commutative99.0%

        \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \color{blue}{\left(0.5 \cdot \left(x + \left(x + \varepsilon\right)\right)\right)}\right) \]
      5. associate-+r+99.0%

        \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right)\right) \]
      6. +-commutative99.0%

        \[\leadsto -2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \left(0.5 \cdot \color{blue}{\left(\varepsilon + \left(x + x\right)\right)}\right)\right) \]
    5. Simplified99.0%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \sin \left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)\right)} \]
    6. Taylor expanded in x around 0 93.9%

      \[\leadsto -2 \cdot \color{blue}{{\sin \left(0.5 \cdot \varepsilon\right)}^{2}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification74.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -0.27 \lor \neg \left(x \leq 5.5 \cdot 10^{-85}\right):\\ \;\;\;\;\mathsf{expm1}\left(\sin x \cdot \left(-\varepsilon\right)\right)\\ \mathbf{else}:\\ \;\;\;\;-2 \cdot {\sin \left(0.5 \cdot \varepsilon\right)}^{2}\\ \end{array} \]

Alternative 12: 67.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\varepsilon \leq -2.35 \cdot 10^{-6} \lor \neg \left(\varepsilon \leq 1.65 \cdot 10^{-12}\right):\\ \;\;\;\;\cos \varepsilon - \cos x\\ \mathbf{else}:\\ \;\;\;\;\sin x \cdot \left(-\varepsilon\right)\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (or (<= eps -2.35e-6) (not (<= eps 1.65e-12)))
   (- (cos eps) (cos x))
   (* (sin x) (- eps))))
double code(double x, double eps) {
	double tmp;
	if ((eps <= -2.35e-6) || !(eps <= 1.65e-12)) {
		tmp = cos(eps) - cos(x);
	} else {
		tmp = sin(x) * -eps;
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if ((eps <= (-2.35d-6)) .or. (.not. (eps <= 1.65d-12))) then
        tmp = cos(eps) - cos(x)
    else
        tmp = sin(x) * -eps
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if ((eps <= -2.35e-6) || !(eps <= 1.65e-12)) {
		tmp = Math.cos(eps) - Math.cos(x);
	} else {
		tmp = Math.sin(x) * -eps;
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if (eps <= -2.35e-6) or not (eps <= 1.65e-12):
		tmp = math.cos(eps) - math.cos(x)
	else:
		tmp = math.sin(x) * -eps
	return tmp
function code(x, eps)
	tmp = 0.0
	if ((eps <= -2.35e-6) || !(eps <= 1.65e-12))
		tmp = Float64(cos(eps) - cos(x));
	else
		tmp = Float64(sin(x) * Float64(-eps));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if ((eps <= -2.35e-6) || ~((eps <= 1.65e-12)))
		tmp = cos(eps) - cos(x);
	else
		tmp = sin(x) * -eps;
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[Or[LessEqual[eps, -2.35e-6], N[Not[LessEqual[eps, 1.65e-12]], $MachinePrecision]], N[(N[Cos[eps], $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision], N[(N[Sin[x], $MachinePrecision] * (-eps)), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\varepsilon \leq -2.35 \cdot 10^{-6} \lor \neg \left(\varepsilon \leq 1.65 \cdot 10^{-12}\right):\\
\;\;\;\;\cos \varepsilon - \cos x\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if eps < -2.34999999999999995e-6 or 1.65e-12 < eps

    1. Initial program 57.6%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Taylor expanded in x around 0 59.4%

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

    if -2.34999999999999995e-6 < eps < 1.65e-12

    1. Initial program 27.0%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Taylor expanded in eps around 0 83.9%

      \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)} \]
    3. Step-by-step derivation
      1. associate-*r*83.9%

        \[\leadsto \color{blue}{\left(-1 \cdot \varepsilon\right) \cdot \sin x} \]
      2. mul-1-neg83.9%

        \[\leadsto \color{blue}{\left(-\varepsilon\right)} \cdot \sin x \]
    4. Simplified83.9%

      \[\leadsto \color{blue}{\left(-\varepsilon\right) \cdot \sin x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification72.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -2.35 \cdot 10^{-6} \lor \neg \left(\varepsilon \leq 1.65 \cdot 10^{-12}\right):\\ \;\;\;\;\cos \varepsilon - \cos x\\ \mathbf{else}:\\ \;\;\;\;\sin x \cdot \left(-\varepsilon\right)\\ \end{array} \]

Alternative 13: 48.5% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos \varepsilon + -1\\ t_1 := \varepsilon \cdot \left(\varepsilon \cdot -0.5\right)\\ \mathbf{if}\;\varepsilon \leq -2.1 \cdot 10^{-7}:\\ \;\;\;\;t_0\\ \mathbf{elif}\;\varepsilon \leq -1.05 \cdot 10^{-193}:\\ \;\;\;\;t_1\\ \mathbf{elif}\;\varepsilon \leq 5.2 \cdot 10^{-155}:\\ \;\;\;\;\varepsilon \cdot \left(-x\right)\\ \mathbf{elif}\;\varepsilon \leq 0.000165:\\ \;\;\;\;t_1\\ \mathbf{else}:\\ \;\;\;\;t_0\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (+ (cos eps) -1.0)) (t_1 (* eps (* eps -0.5))))
   (if (<= eps -2.1e-7)
     t_0
     (if (<= eps -1.05e-193)
       t_1
       (if (<= eps 5.2e-155) (* eps (- x)) (if (<= eps 0.000165) t_1 t_0))))))
double code(double x, double eps) {
	double t_0 = cos(eps) + -1.0;
	double t_1 = eps * (eps * -0.5);
	double tmp;
	if (eps <= -2.1e-7) {
		tmp = t_0;
	} else if (eps <= -1.05e-193) {
		tmp = t_1;
	} else if (eps <= 5.2e-155) {
		tmp = eps * -x;
	} else if (eps <= 0.000165) {
		tmp = t_1;
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = cos(eps) + (-1.0d0)
    t_1 = eps * (eps * (-0.5d0))
    if (eps <= (-2.1d-7)) then
        tmp = t_0
    else if (eps <= (-1.05d-193)) then
        tmp = t_1
    else if (eps <= 5.2d-155) then
        tmp = eps * -x
    else if (eps <= 0.000165d0) then
        tmp = t_1
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double t_0 = Math.cos(eps) + -1.0;
	double t_1 = eps * (eps * -0.5);
	double tmp;
	if (eps <= -2.1e-7) {
		tmp = t_0;
	} else if (eps <= -1.05e-193) {
		tmp = t_1;
	} else if (eps <= 5.2e-155) {
		tmp = eps * -x;
	} else if (eps <= 0.000165) {
		tmp = t_1;
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x, eps):
	t_0 = math.cos(eps) + -1.0
	t_1 = eps * (eps * -0.5)
	tmp = 0
	if eps <= -2.1e-7:
		tmp = t_0
	elif eps <= -1.05e-193:
		tmp = t_1
	elif eps <= 5.2e-155:
		tmp = eps * -x
	elif eps <= 0.000165:
		tmp = t_1
	else:
		tmp = t_0
	return tmp
function code(x, eps)
	t_0 = Float64(cos(eps) + -1.0)
	t_1 = Float64(eps * Float64(eps * -0.5))
	tmp = 0.0
	if (eps <= -2.1e-7)
		tmp = t_0;
	elseif (eps <= -1.05e-193)
		tmp = t_1;
	elseif (eps <= 5.2e-155)
		tmp = Float64(eps * Float64(-x));
	elseif (eps <= 0.000165)
		tmp = t_1;
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x, eps)
	t_0 = cos(eps) + -1.0;
	t_1 = eps * (eps * -0.5);
	tmp = 0.0;
	if (eps <= -2.1e-7)
		tmp = t_0;
	elseif (eps <= -1.05e-193)
		tmp = t_1;
	elseif (eps <= 5.2e-155)
		tmp = eps * -x;
	elseif (eps <= 0.000165)
		tmp = t_1;
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_, eps_] := Block[{t$95$0 = N[(N[Cos[eps], $MachinePrecision] + -1.0), $MachinePrecision]}, Block[{t$95$1 = N[(eps * N[(eps * -0.5), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[eps, -2.1e-7], t$95$0, If[LessEqual[eps, -1.05e-193], t$95$1, If[LessEqual[eps, 5.2e-155], N[(eps * (-x)), $MachinePrecision], If[LessEqual[eps, 0.000165], t$95$1, t$95$0]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos \varepsilon + -1\\
t_1 := \varepsilon \cdot \left(\varepsilon \cdot -0.5\right)\\
\mathbf{if}\;\varepsilon \leq -2.1 \cdot 10^{-7}:\\
\;\;\;\;t_0\\

\mathbf{elif}\;\varepsilon \leq -1.05 \cdot 10^{-193}:\\
\;\;\;\;t_1\\

\mathbf{elif}\;\varepsilon \leq 5.2 \cdot 10^{-155}:\\
\;\;\;\;\varepsilon \cdot \left(-x\right)\\

\mathbf{elif}\;\varepsilon \leq 0.000165:\\
\;\;\;\;t_1\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if eps < -2.1e-7 or 1.65e-4 < eps

    1. Initial program 57.8%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Taylor expanded in x around 0 58.1%

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

    if -2.1e-7 < eps < -1.05e-193 or 5.20000000000000016e-155 < eps < 1.65e-4

    1. Initial program 8.0%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Taylor expanded in x around 0 8.0%

      \[\leadsto \color{blue}{\cos \varepsilon - 1} \]
    3. Taylor expanded in eps around 0 39.1%

      \[\leadsto \color{blue}{-0.5 \cdot {\varepsilon}^{2}} \]
    4. Step-by-step derivation
      1. *-commutative39.1%

        \[\leadsto \color{blue}{{\varepsilon}^{2} \cdot -0.5} \]
      2. unpow239.1%

        \[\leadsto \color{blue}{\left(\varepsilon \cdot \varepsilon\right)} \cdot -0.5 \]
      3. associate-*l*39.1%

        \[\leadsto \color{blue}{\varepsilon \cdot \left(\varepsilon \cdot -0.5\right)} \]
    5. Simplified39.1%

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

    if -1.05e-193 < eps < 5.20000000000000016e-155

    1. Initial program 47.9%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Taylor expanded in eps around 0 99.9%

      \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)} \]
    3. Step-by-step derivation
      1. associate-*r*99.9%

        \[\leadsto \color{blue}{\left(-1 \cdot \varepsilon\right) \cdot \sin x} \]
      2. mul-1-neg99.9%

        \[\leadsto \color{blue}{\left(-\varepsilon\right)} \cdot \sin x \]
    4. Simplified99.9%

      \[\leadsto \color{blue}{\left(-\varepsilon\right) \cdot \sin x} \]
    5. Taylor expanded in x around 0 61.9%

      \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot x\right)} \]
    6. Step-by-step derivation
      1. associate-*r*61.9%

        \[\leadsto \color{blue}{\left(-1 \cdot \varepsilon\right) \cdot x} \]
      2. mul-1-neg61.9%

        \[\leadsto \color{blue}{\left(-\varepsilon\right)} \cdot x \]
    7. Simplified61.9%

      \[\leadsto \color{blue}{\left(-\varepsilon\right) \cdot x} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification53.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -2.1 \cdot 10^{-7}:\\ \;\;\;\;\cos \varepsilon + -1\\ \mathbf{elif}\;\varepsilon \leq -1.05 \cdot 10^{-193}:\\ \;\;\;\;\varepsilon \cdot \left(\varepsilon \cdot -0.5\right)\\ \mathbf{elif}\;\varepsilon \leq 5.2 \cdot 10^{-155}:\\ \;\;\;\;\varepsilon \cdot \left(-x\right)\\ \mathbf{elif}\;\varepsilon \leq 0.000165:\\ \;\;\;\;\varepsilon \cdot \left(\varepsilon \cdot -0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\cos \varepsilon + -1\\ \end{array} \]

Alternative 14: 66.9% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\varepsilon \leq -7 \cdot 10^{-6} \lor \neg \left(\varepsilon \leq 1.65 \cdot 10^{-12}\right):\\ \;\;\;\;\cos \varepsilon + -1\\ \mathbf{else}:\\ \;\;\;\;\sin x \cdot \left(-\varepsilon\right)\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (or (<= eps -7e-6) (not (<= eps 1.65e-12)))
   (+ (cos eps) -1.0)
   (* (sin x) (- eps))))
double code(double x, double eps) {
	double tmp;
	if ((eps <= -7e-6) || !(eps <= 1.65e-12)) {
		tmp = cos(eps) + -1.0;
	} else {
		tmp = sin(x) * -eps;
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if ((eps <= (-7d-6)) .or. (.not. (eps <= 1.65d-12))) then
        tmp = cos(eps) + (-1.0d0)
    else
        tmp = sin(x) * -eps
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if ((eps <= -7e-6) || !(eps <= 1.65e-12)) {
		tmp = Math.cos(eps) + -1.0;
	} else {
		tmp = Math.sin(x) * -eps;
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if (eps <= -7e-6) or not (eps <= 1.65e-12):
		tmp = math.cos(eps) + -1.0
	else:
		tmp = math.sin(x) * -eps
	return tmp
function code(x, eps)
	tmp = 0.0
	if ((eps <= -7e-6) || !(eps <= 1.65e-12))
		tmp = Float64(cos(eps) + -1.0);
	else
		tmp = Float64(sin(x) * Float64(-eps));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if ((eps <= -7e-6) || ~((eps <= 1.65e-12)))
		tmp = cos(eps) + -1.0;
	else
		tmp = sin(x) * -eps;
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[Or[LessEqual[eps, -7e-6], N[Not[LessEqual[eps, 1.65e-12]], $MachinePrecision]], N[(N[Cos[eps], $MachinePrecision] + -1.0), $MachinePrecision], N[(N[Sin[x], $MachinePrecision] * (-eps)), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\varepsilon \leq -7 \cdot 10^{-6} \lor \neg \left(\varepsilon \leq 1.65 \cdot 10^{-12}\right):\\
\;\;\;\;\cos \varepsilon + -1\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if eps < -6.99999999999999989e-6 or 1.65e-12 < eps

    1. Initial program 57.6%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Taylor expanded in x around 0 57.9%

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

    if -6.99999999999999989e-6 < eps < 1.65e-12

    1. Initial program 27.0%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Taylor expanded in eps around 0 83.9%

      \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)} \]
    3. Step-by-step derivation
      1. associate-*r*83.9%

        \[\leadsto \color{blue}{\left(-1 \cdot \varepsilon\right) \cdot \sin x} \]
      2. mul-1-neg83.9%

        \[\leadsto \color{blue}{\left(-\varepsilon\right)} \cdot \sin x \]
    4. Simplified83.9%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -7 \cdot 10^{-6} \lor \neg \left(\varepsilon \leq 1.65 \cdot 10^{-12}\right):\\ \;\;\;\;\cos \varepsilon + -1\\ \mathbf{else}:\\ \;\;\;\;\sin x \cdot \left(-\varepsilon\right)\\ \end{array} \]

Alternative 15: 22.8% accurate, 29.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 2.5 \cdot 10^{-124}:\\ \;\;\;\;\varepsilon \cdot \left(\varepsilon \cdot -0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\varepsilon \cdot \left(-x\right)\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (<= x 2.5e-124) (* eps (* eps -0.5)) (* eps (- x))))
double code(double x, double eps) {
	double tmp;
	if (x <= 2.5e-124) {
		tmp = eps * (eps * -0.5);
	} else {
		tmp = eps * -x;
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if (x <= 2.5d-124) then
        tmp = eps * (eps * (-0.5d0))
    else
        tmp = eps * -x
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if (x <= 2.5e-124) {
		tmp = eps * (eps * -0.5);
	} else {
		tmp = eps * -x;
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if x <= 2.5e-124:
		tmp = eps * (eps * -0.5)
	else:
		tmp = eps * -x
	return tmp
function code(x, eps)
	tmp = 0.0
	if (x <= 2.5e-124)
		tmp = Float64(eps * Float64(eps * -0.5));
	else
		tmp = Float64(eps * Float64(-x));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if (x <= 2.5e-124)
		tmp = eps * (eps * -0.5);
	else
		tmp = eps * -x;
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[LessEqual[x, 2.5e-124], N[(eps * N[(eps * -0.5), $MachinePrecision]), $MachinePrecision], N[(eps * (-x)), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 2.5 \cdot 10^{-124}:\\
\;\;\;\;\varepsilon \cdot \left(\varepsilon \cdot -0.5\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 2.5000000000000001e-124

    1. Initial program 52.9%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Taylor expanded in x around 0 53.0%

      \[\leadsto \color{blue}{\cos \varepsilon - 1} \]
    3. Taylor expanded in eps around 0 33.1%

      \[\leadsto \color{blue}{-0.5 \cdot {\varepsilon}^{2}} \]
    4. Step-by-step derivation
      1. *-commutative33.1%

        \[\leadsto \color{blue}{{\varepsilon}^{2} \cdot -0.5} \]
      2. unpow233.1%

        \[\leadsto \color{blue}{\left(\varepsilon \cdot \varepsilon\right)} \cdot -0.5 \]
      3. associate-*l*33.1%

        \[\leadsto \color{blue}{\varepsilon \cdot \left(\varepsilon \cdot -0.5\right)} \]
    5. Simplified33.1%

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

    if 2.5000000000000001e-124 < x

    1. Initial program 21.0%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Taylor expanded in eps around 0 56.1%

      \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)} \]
    3. Step-by-step derivation
      1. associate-*r*56.1%

        \[\leadsto \color{blue}{\left(-1 \cdot \varepsilon\right) \cdot \sin x} \]
      2. mul-1-neg56.1%

        \[\leadsto \color{blue}{\left(-\varepsilon\right)} \cdot \sin x \]
    4. Simplified56.1%

      \[\leadsto \color{blue}{\left(-\varepsilon\right) \cdot \sin x} \]
    5. Taylor expanded in x around 0 19.9%

      \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot x\right)} \]
    6. Step-by-step derivation
      1. associate-*r*19.9%

        \[\leadsto \color{blue}{\left(-1 \cdot \varepsilon\right) \cdot x} \]
      2. mul-1-neg19.9%

        \[\leadsto \color{blue}{\left(-\varepsilon\right)} \cdot x \]
    7. Simplified19.9%

      \[\leadsto \color{blue}{\left(-\varepsilon\right) \cdot x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification28.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 2.5 \cdot 10^{-124}:\\ \;\;\;\;\varepsilon \cdot \left(\varepsilon \cdot -0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\varepsilon \cdot \left(-x\right)\\ \end{array} \]

Alternative 16: 17.7% accurate, 51.3× speedup?

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

\\
\varepsilon \cdot \left(-x\right)
\end{array}
Derivation
  1. Initial program 41.7%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  2. Taylor expanded in eps around 0 45.5%

    \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)} \]
  3. Step-by-step derivation
    1. associate-*r*45.5%

      \[\leadsto \color{blue}{\left(-1 \cdot \varepsilon\right) \cdot \sin x} \]
    2. mul-1-neg45.5%

      \[\leadsto \color{blue}{\left(-\varepsilon\right)} \cdot \sin x \]
  4. Simplified45.5%

    \[\leadsto \color{blue}{\left(-\varepsilon\right) \cdot \sin x} \]
  5. Taylor expanded in x around 0 21.2%

    \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot x\right)} \]
  6. Step-by-step derivation
    1. associate-*r*21.2%

      \[\leadsto \color{blue}{\left(-1 \cdot \varepsilon\right) \cdot x} \]
    2. mul-1-neg21.2%

      \[\leadsto \color{blue}{\left(-\varepsilon\right)} \cdot x \]
  7. Simplified21.2%

    \[\leadsto \color{blue}{\left(-\varepsilon\right) \cdot x} \]
  8. Final simplification21.2%

    \[\leadsto \varepsilon \cdot \left(-x\right) \]

Alternative 17: 12.6% 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 41.7%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  2. Step-by-step derivation
    1. add-cube-cbrt41.4%

      \[\leadsto \color{blue}{\left(\sqrt[3]{\cos \left(x + \varepsilon\right)} \cdot \sqrt[3]{\cos \left(x + \varepsilon\right)}\right) \cdot \sqrt[3]{\cos \left(x + \varepsilon\right)}} - \cos x \]
    2. pow341.4%

      \[\leadsto \color{blue}{{\left(\sqrt[3]{\cos \left(x + \varepsilon\right)}\right)}^{3}} - \cos x \]
  3. Applied egg-rr41.4%

    \[\leadsto \color{blue}{{\left(\sqrt[3]{\cos \left(x + \varepsilon\right)}\right)}^{3}} - \cos x \]
  4. Taylor expanded in eps around 0 15.5%

    \[\leadsto \color{blue}{\cos x \cdot {1}^{0.3333333333333333} - \cos x} \]
  5. Step-by-step derivation
    1. pow-base-115.5%

      \[\leadsto \cos x \cdot \color{blue}{1} - \cos x \]
    2. *-rgt-identity15.5%

      \[\leadsto \color{blue}{\cos x} - \cos x \]
    3. +-inverses15.5%

      \[\leadsto \color{blue}{0} \]
  6. Simplified15.5%

    \[\leadsto \color{blue}{0} \]
  7. Final simplification15.5%

    \[\leadsto 0 \]

Reproduce

?
herbie shell --seed 2023182 
(FPCore (x eps)
  :name "2cos (problem 3.3.5)"
  :precision binary64
  (- (cos (+ x eps)) (cos x)))