2cos (problem 3.3.5)

Percentage Accurate: 52.1% → 99.7%
Time: 17.4s
Alternatives: 13
Speedup: 25.9×

Specification

?
\[\left(\left(-10000 \leq x \land x \leq 10000\right) \land 10^{-16} \cdot \left|x\right| < \varepsilon\right) \land \varepsilon < \left|x\right|\]
\[\begin{array}{l} \\ \cos \left(x + \varepsilon\right) - \cos x \end{array} \]
(FPCore (x eps) :precision binary64 (- (cos (+ x eps)) (cos x)))
double code(double x, double eps) {
	return cos((x + eps)) - cos(x);
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = cos((x + eps)) - cos(x)
end function
public static double code(double x, double eps) {
	return Math.cos((x + eps)) - Math.cos(x);
}
def code(x, eps):
	return math.cos((x + eps)) - math.cos(x)
function code(x, eps)
	return Float64(cos(Float64(x + eps)) - cos(x))
end
function tmp = code(x, eps)
	tmp = cos((x + eps)) - cos(x);
end
code[x_, eps_] := N[(N[Cos[N[(x + eps), $MachinePrecision]], $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

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

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 13 alternatives:

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

Initial Program: 52.1% 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: 99.7% accurate, 0.9× speedup?

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

\\
\left(\sin \left(\varepsilon \cdot 0.5\right) \cdot \sin \left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right)\right) \cdot -2
\end{array}
Derivation
  1. Initial program 52.2%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift--.f64N/A

      \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) - \cos x} \]
    2. lift-cos.f64N/A

      \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right)} - \cos x \]
    3. lift-cos.f64N/A

      \[\leadsto \cos \left(x + \varepsilon\right) - \color{blue}{\cos x} \]
    4. diff-cosN/A

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

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

      \[\leadsto \color{blue}{\left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \cdot -2} \]
  4. Applied rewrites99.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \left(\sin \left(\frac{1}{2} \cdot \varepsilon\right) \cdot \sin \left(\frac{1}{2} \cdot \varepsilon + \color{blue}{x}\right)\right) \cdot -2 \]
    13. lower-fma.f6499.7

      \[\leadsto \left(\sin \left(0.5 \cdot \varepsilon\right) \cdot \sin \color{blue}{\left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right)}\right) \cdot -2 \]
  7. Applied rewrites99.7%

    \[\leadsto \color{blue}{\left(\sin \left(0.5 \cdot \varepsilon\right) \cdot \sin \left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right)\right)} \cdot -2 \]
  8. Final simplification99.7%

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

Alternative 2: 99.5% accurate, 1.3× speedup?

\[\begin{array}{l} \\ -2 \cdot \left(\sin \left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right) \cdot \left(\varepsilon \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon \cdot \varepsilon, -1.5500992063492063 \cdot 10^{-6}, 0.00026041666666666666\right), -0.020833333333333332\right), 0.5\right)\right)\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (*
  -2.0
  (*
   (sin (fma 0.5 eps x))
   (*
    eps
    (fma
     eps
     (*
      eps
      (fma
       (* eps eps)
       (fma (* eps eps) -1.5500992063492063e-6 0.00026041666666666666)
       -0.020833333333333332))
     0.5)))))
double code(double x, double eps) {
	return -2.0 * (sin(fma(0.5, eps, x)) * (eps * fma(eps, (eps * fma((eps * eps), fma((eps * eps), -1.5500992063492063e-6, 0.00026041666666666666), -0.020833333333333332)), 0.5)));
}
function code(x, eps)
	return Float64(-2.0 * Float64(sin(fma(0.5, eps, x)) * Float64(eps * fma(eps, Float64(eps * fma(Float64(eps * eps), fma(Float64(eps * eps), -1.5500992063492063e-6, 0.00026041666666666666), -0.020833333333333332)), 0.5))))
end
code[x_, eps_] := N[(-2.0 * N[(N[Sin[N[(0.5 * eps + x), $MachinePrecision]], $MachinePrecision] * N[(eps * N[(eps * N[(eps * N[(N[(eps * eps), $MachinePrecision] * N[(N[(eps * eps), $MachinePrecision] * -1.5500992063492063e-6 + 0.00026041666666666666), $MachinePrecision] + -0.020833333333333332), $MachinePrecision]), $MachinePrecision] + 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
-2 \cdot \left(\sin \left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right) \cdot \left(\varepsilon \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon \cdot \varepsilon, -1.5500992063492063 \cdot 10^{-6}, 0.00026041666666666666\right), -0.020833333333333332\right), 0.5\right)\right)\right)
\end{array}
Derivation
  1. Initial program 52.2%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift--.f64N/A

      \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) - \cos x} \]
    2. lift-cos.f64N/A

      \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right)} - \cos x \]
    3. lift-cos.f64N/A

      \[\leadsto \cos \left(x + \varepsilon\right) - \color{blue}{\cos x} \]
    4. diff-cosN/A

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

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

      \[\leadsto \color{blue}{\left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \cdot -2} \]
  4. Applied rewrites99.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \left(\sin \left(\frac{1}{2} \cdot \varepsilon\right) \cdot \sin \left(\frac{1}{2} \cdot \varepsilon + \color{blue}{x}\right)\right) \cdot -2 \]
    13. lower-fma.f6499.7

      \[\leadsto \left(\sin \left(0.5 \cdot \varepsilon\right) \cdot \sin \color{blue}{\left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right)}\right) \cdot -2 \]
  7. Applied rewrites99.7%

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

    \[\leadsto \left(\left(\varepsilon \cdot \left(\frac{1}{2} + {\varepsilon}^{2} \cdot \left({\varepsilon}^{2} \cdot \left(\frac{1}{3840} + \frac{-1}{645120} \cdot {\varepsilon}^{2}\right) - \frac{1}{48}\right)\right)\right) \cdot \sin \color{blue}{\left(\mathsf{fma}\left(\frac{1}{2}, \varepsilon, x\right)\right)}\right) \cdot -2 \]
  9. Step-by-step derivation
    1. Applied rewrites99.7%

      \[\leadsto \left(\left(\varepsilon \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon \cdot \varepsilon, -1.5500992063492063 \cdot 10^{-6}, 0.00026041666666666666\right), -0.020833333333333332\right), 0.5\right)\right) \cdot \sin \color{blue}{\left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right)}\right) \cdot -2 \]
    2. Final simplification99.7%

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

    Alternative 3: 99.5% accurate, 1.4× speedup?

    \[\begin{array}{l} \\ -2 \cdot \left(\sin \left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right) \cdot \left(\varepsilon \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.00026041666666666666, -0.020833333333333332\right), 0.5\right)\right)\right) \end{array} \]
    (FPCore (x eps)
     :precision binary64
     (*
      -2.0
      (*
       (sin (fma 0.5 eps x))
       (*
        eps
        (fma
         eps
         (* eps (fma eps (* eps 0.00026041666666666666) -0.020833333333333332))
         0.5)))))
    double code(double x, double eps) {
    	return -2.0 * (sin(fma(0.5, eps, x)) * (eps * fma(eps, (eps * fma(eps, (eps * 0.00026041666666666666), -0.020833333333333332)), 0.5)));
    }
    
    function code(x, eps)
    	return Float64(-2.0 * Float64(sin(fma(0.5, eps, x)) * Float64(eps * fma(eps, Float64(eps * fma(eps, Float64(eps * 0.00026041666666666666), -0.020833333333333332)), 0.5))))
    end
    
    code[x_, eps_] := N[(-2.0 * N[(N[Sin[N[(0.5 * eps + x), $MachinePrecision]], $MachinePrecision] * N[(eps * N[(eps * N[(eps * N[(eps * N[(eps * 0.00026041666666666666), $MachinePrecision] + -0.020833333333333332), $MachinePrecision]), $MachinePrecision] + 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    -2 \cdot \left(\sin \left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right) \cdot \left(\varepsilon \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.00026041666666666666, -0.020833333333333332\right), 0.5\right)\right)\right)
    \end{array}
    
    Derivation
    1. Initial program 52.2%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift--.f64N/A

        \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) - \cos x} \]
      2. lift-cos.f64N/A

        \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right)} - \cos x \]
      3. lift-cos.f64N/A

        \[\leadsto \cos \left(x + \varepsilon\right) - \color{blue}{\cos x} \]
      4. diff-cosN/A

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

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

        \[\leadsto \color{blue}{\left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \cdot -2} \]
    4. Applied rewrites99.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(\sin \left(\frac{1}{2} \cdot \varepsilon\right) \cdot \sin \left(\frac{1}{2} \cdot \varepsilon + \color{blue}{x}\right)\right) \cdot -2 \]
      13. lower-fma.f6499.7

        \[\leadsto \left(\sin \left(0.5 \cdot \varepsilon\right) \cdot \sin \color{blue}{\left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right)}\right) \cdot -2 \]
    7. Applied rewrites99.7%

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

      \[\leadsto \left(\left(\varepsilon \cdot \left(\frac{1}{2} + {\varepsilon}^{2} \cdot \left(\frac{1}{3840} \cdot {\varepsilon}^{2} - \frac{1}{48}\right)\right)\right) \cdot \sin \color{blue}{\left(\mathsf{fma}\left(\frac{1}{2}, \varepsilon, x\right)\right)}\right) \cdot -2 \]
    9. Step-by-step derivation
      1. Applied rewrites99.6%

        \[\leadsto \left(\left(\varepsilon \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.00026041666666666666, -0.020833333333333332\right), 0.5\right)\right) \cdot \sin \color{blue}{\left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right)}\right) \cdot -2 \]
      2. Final simplification99.6%

        \[\leadsto -2 \cdot \left(\sin \left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right) \cdot \left(\varepsilon \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.00026041666666666666, -0.020833333333333332\right), 0.5\right)\right)\right) \]
      3. Add Preprocessing

      Alternative 4: 99.4% accurate, 1.6× speedup?

      \[\begin{array}{l} \\ -2 \cdot \left(\sin \left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right) \cdot \left(\varepsilon \cdot \mathsf{fma}\left(-0.020833333333333332, \varepsilon \cdot \varepsilon, 0.5\right)\right)\right) \end{array} \]
      (FPCore (x eps)
       :precision binary64
       (*
        -2.0
        (*
         (sin (fma 0.5 eps x))
         (* eps (fma -0.020833333333333332 (* eps eps) 0.5)))))
      double code(double x, double eps) {
      	return -2.0 * (sin(fma(0.5, eps, x)) * (eps * fma(-0.020833333333333332, (eps * eps), 0.5)));
      }
      
      function code(x, eps)
      	return Float64(-2.0 * Float64(sin(fma(0.5, eps, x)) * Float64(eps * fma(-0.020833333333333332, Float64(eps * eps), 0.5))))
      end
      
      code[x_, eps_] := N[(-2.0 * N[(N[Sin[N[(0.5 * eps + x), $MachinePrecision]], $MachinePrecision] * N[(eps * N[(-0.020833333333333332 * N[(eps * eps), $MachinePrecision] + 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      -2 \cdot \left(\sin \left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right) \cdot \left(\varepsilon \cdot \mathsf{fma}\left(-0.020833333333333332, \varepsilon \cdot \varepsilon, 0.5\right)\right)\right)
      \end{array}
      
      Derivation
      1. Initial program 52.2%

        \[\cos \left(x + \varepsilon\right) - \cos x \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift--.f64N/A

          \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) - \cos x} \]
        2. lift-cos.f64N/A

          \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right)} - \cos x \]
        3. lift-cos.f64N/A

          \[\leadsto \cos \left(x + \varepsilon\right) - \color{blue}{\cos x} \]
        4. diff-cosN/A

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

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

          \[\leadsto \color{blue}{\left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \cdot -2} \]
      4. Applied rewrites99.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \left(\sin \left(\frac{1}{2} \cdot \varepsilon\right) \cdot \sin \left(\frac{1}{2} \cdot \varepsilon + \color{blue}{x}\right)\right) \cdot -2 \]
        13. lower-fma.f6499.7

          \[\leadsto \left(\sin \left(0.5 \cdot \varepsilon\right) \cdot \sin \color{blue}{\left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right)}\right) \cdot -2 \]
      7. Applied rewrites99.7%

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

        \[\leadsto \left(\left(\varepsilon \cdot \left(\frac{1}{2} + \frac{-1}{48} \cdot {\varepsilon}^{2}\right)\right) \cdot \sin \color{blue}{\left(\mathsf{fma}\left(\frac{1}{2}, \varepsilon, x\right)\right)}\right) \cdot -2 \]
      9. Step-by-step derivation
        1. Applied rewrites99.5%

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

          \[\leadsto -2 \cdot \left(\sin \left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right) \cdot \left(\varepsilon \cdot \mathsf{fma}\left(-0.020833333333333332, \varepsilon \cdot \varepsilon, 0.5\right)\right)\right) \]
        3. Add Preprocessing

        Alternative 5: 99.2% accurate, 1.7× speedup?

        \[\begin{array}{l} \\ -2 \cdot \left(\sin \left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right) \cdot \left(\varepsilon \cdot 0.5\right)\right) \end{array} \]
        (FPCore (x eps)
         :precision binary64
         (* -2.0 (* (sin (fma 0.5 eps x)) (* eps 0.5))))
        double code(double x, double eps) {
        	return -2.0 * (sin(fma(0.5, eps, x)) * (eps * 0.5));
        }
        
        function code(x, eps)
        	return Float64(-2.0 * Float64(sin(fma(0.5, eps, x)) * Float64(eps * 0.5)))
        end
        
        code[x_, eps_] := N[(-2.0 * N[(N[Sin[N[(0.5 * eps + x), $MachinePrecision]], $MachinePrecision] * N[(eps * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
        
        \begin{array}{l}
        
        \\
        -2 \cdot \left(\sin \left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right) \cdot \left(\varepsilon \cdot 0.5\right)\right)
        \end{array}
        
        Derivation
        1. Initial program 52.2%

          \[\cos \left(x + \varepsilon\right) - \cos x \]
        2. Add Preprocessing
        3. Step-by-step derivation
          1. lift--.f64N/A

            \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) - \cos x} \]
          2. lift-cos.f64N/A

            \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right)} - \cos x \]
          3. lift-cos.f64N/A

            \[\leadsto \cos \left(x + \varepsilon\right) - \color{blue}{\cos x} \]
          4. diff-cosN/A

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

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

            \[\leadsto \color{blue}{\left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \cdot -2} \]
        4. Applied rewrites99.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \left(\sin \left(\frac{1}{2} \cdot \varepsilon\right) \cdot \sin \left(\frac{1}{2} \cdot \varepsilon + \color{blue}{x}\right)\right) \cdot -2 \]
          13. lower-fma.f6499.7

            \[\leadsto \left(\sin \left(0.5 \cdot \varepsilon\right) \cdot \sin \color{blue}{\left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right)}\right) \cdot -2 \]
        7. Applied rewrites99.7%

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

          \[\leadsto \left(\left(\frac{1}{2} \cdot \varepsilon\right) \cdot \sin \color{blue}{\left(\mathsf{fma}\left(\frac{1}{2}, \varepsilon, x\right)\right)}\right) \cdot -2 \]
        9. Step-by-step derivation
          1. Applied rewrites99.3%

            \[\leadsto \left(\left(\varepsilon \cdot 0.5\right) \cdot \sin \color{blue}{\left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right)}\right) \cdot -2 \]
          2. Final simplification99.3%

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

          Alternative 6: 98.4% accurate, 2.7× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} t_0 := \mathsf{fma}\left(\varepsilon \cdot \varepsilon, 0.16666666666666666, -1\right)\\ \mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.25, -0.16666666666666666 \cdot \left(\varepsilon \cdot \left(x \cdot t\_0\right)\right)\right), \varepsilon \cdot t\_0\right), \varepsilon \cdot \left(\varepsilon \cdot -0.5\right)\right) \end{array} \end{array} \]
          (FPCore (x eps)
           :precision binary64
           (let* ((t_0 (fma (* eps eps) 0.16666666666666666 -1.0)))
             (fma
              x
              (fma
               x
               (fma eps (* eps 0.25) (* -0.16666666666666666 (* eps (* x t_0))))
               (* eps t_0))
              (* eps (* eps -0.5)))))
          double code(double x, double eps) {
          	double t_0 = fma((eps * eps), 0.16666666666666666, -1.0);
          	return fma(x, fma(x, fma(eps, (eps * 0.25), (-0.16666666666666666 * (eps * (x * t_0)))), (eps * t_0)), (eps * (eps * -0.5)));
          }
          
          function code(x, eps)
          	t_0 = fma(Float64(eps * eps), 0.16666666666666666, -1.0)
          	return fma(x, fma(x, fma(eps, Float64(eps * 0.25), Float64(-0.16666666666666666 * Float64(eps * Float64(x * t_0)))), Float64(eps * t_0)), Float64(eps * Float64(eps * -0.5)))
          end
          
          code[x_, eps_] := Block[{t$95$0 = N[(N[(eps * eps), $MachinePrecision] * 0.16666666666666666 + -1.0), $MachinePrecision]}, N[(x * N[(x * N[(eps * N[(eps * 0.25), $MachinePrecision] + N[(-0.16666666666666666 * N[(eps * N[(x * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(eps * t$95$0), $MachinePrecision]), $MachinePrecision] + N[(eps * N[(eps * -0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          t_0 := \mathsf{fma}\left(\varepsilon \cdot \varepsilon, 0.16666666666666666, -1\right)\\
          \mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.25, -0.16666666666666666 \cdot \left(\varepsilon \cdot \left(x \cdot t\_0\right)\right)\right), \varepsilon \cdot t\_0\right), \varepsilon \cdot \left(\varepsilon \cdot -0.5\right)\right)
          \end{array}
          \end{array}
          
          Derivation
          1. Initial program 52.2%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \frac{-1}{2} \cdot \cos x, \sin x \cdot \color{blue}{\mathsf{fma}\left(\varepsilon, \frac{1}{6} \cdot \varepsilon, -1\right)}\right) \]
          5. Applied rewrites99.5%

            \[\leadsto \color{blue}{\varepsilon \cdot \mathsf{fma}\left(\varepsilon, -0.5 \cdot \cos x, \sin x \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.16666666666666666, -1\right)\right)} \]
          6. Taylor expanded in x around 0

            \[\leadsto \varepsilon \cdot \left(\frac{-1}{2} \cdot \varepsilon + \color{blue}{x \cdot \left(\left(\frac{1}{6} \cdot {\varepsilon}^{2} + \frac{1}{4} \cdot \left(\varepsilon \cdot x\right)\right) - 1\right)}\right) \]
          7. Step-by-step derivation
            1. Applied rewrites98.2%

              \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \color{blue}{-0.5}, x \cdot \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(\varepsilon, 0.16666666666666666, x \cdot 0.25\right), -1\right)\right) \]
            2. Taylor expanded in eps around 0

              \[\leadsto \varepsilon \cdot \left(-1 \cdot x\right) \]
            3. Step-by-step derivation
              1. Applied rewrites79.7%

                \[\leadsto \varepsilon \cdot \left(-x\right) \]
              2. Taylor expanded in x around 0

                \[\leadsto \frac{-1}{2} \cdot {\varepsilon}^{2} + \color{blue}{x \cdot \left(\varepsilon \cdot \left(\frac{1}{6} \cdot {\varepsilon}^{2} - 1\right) + x \cdot \left(\frac{-1}{6} \cdot \left(\varepsilon \cdot \left(x \cdot \left(\frac{1}{6} \cdot {\varepsilon}^{2} - 1\right)\right)\right) + \frac{1}{4} \cdot {\varepsilon}^{2}\right)\right)} \]
              3. Applied rewrites98.6%

                \[\leadsto \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.25, -0.16666666666666666 \cdot \left(\varepsilon \cdot \left(x \cdot \mathsf{fma}\left(\varepsilon \cdot \varepsilon, 0.16666666666666666, -1\right)\right)\right)\right), \varepsilon \cdot \mathsf{fma}\left(\varepsilon \cdot \varepsilon, 0.16666666666666666, -1\right)\right)}, \varepsilon \cdot \left(\varepsilon \cdot -0.5\right)\right) \]
              4. Add Preprocessing

              Alternative 7: 98.2% accurate, 2.9× speedup?

              \[\begin{array}{l} \\ \begin{array}{l} t_0 := \mathsf{fma}\left(0.16666666666666666, \varepsilon \cdot \varepsilon, -1\right)\\ \mathsf{fma}\left(x \cdot x, \varepsilon \cdot \mathsf{fma}\left(x, -0.16666666666666666 \cdot t\_0, \varepsilon \cdot 0.25\right), \varepsilon \cdot \mathsf{fma}\left(x, t\_0, \varepsilon \cdot -0.5\right)\right) \end{array} \end{array} \]
              (FPCore (x eps)
               :precision binary64
               (let* ((t_0 (fma 0.16666666666666666 (* eps eps) -1.0)))
                 (fma
                  (* x x)
                  (* eps (fma x (* -0.16666666666666666 t_0) (* eps 0.25)))
                  (* eps (fma x t_0 (* eps -0.5))))))
              double code(double x, double eps) {
              	double t_0 = fma(0.16666666666666666, (eps * eps), -1.0);
              	return fma((x * x), (eps * fma(x, (-0.16666666666666666 * t_0), (eps * 0.25))), (eps * fma(x, t_0, (eps * -0.5))));
              }
              
              function code(x, eps)
              	t_0 = fma(0.16666666666666666, Float64(eps * eps), -1.0)
              	return fma(Float64(x * x), Float64(eps * fma(x, Float64(-0.16666666666666666 * t_0), Float64(eps * 0.25))), Float64(eps * fma(x, t_0, Float64(eps * -0.5))))
              end
              
              code[x_, eps_] := Block[{t$95$0 = N[(0.16666666666666666 * N[(eps * eps), $MachinePrecision] + -1.0), $MachinePrecision]}, N[(N[(x * x), $MachinePrecision] * N[(eps * N[(x * N[(-0.16666666666666666 * t$95$0), $MachinePrecision] + N[(eps * 0.25), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(eps * N[(x * t$95$0 + N[(eps * -0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
              
              \begin{array}{l}
              
              \\
              \begin{array}{l}
              t_0 := \mathsf{fma}\left(0.16666666666666666, \varepsilon \cdot \varepsilon, -1\right)\\
              \mathsf{fma}\left(x \cdot x, \varepsilon \cdot \mathsf{fma}\left(x, -0.16666666666666666 \cdot t\_0, \varepsilon \cdot 0.25\right), \varepsilon \cdot \mathsf{fma}\left(x, t\_0, \varepsilon \cdot -0.5\right)\right)
              \end{array}
              \end{array}
              
              Derivation
              1. Initial program 52.2%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                  \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \frac{-1}{2} \cdot \cos x, \sin x \cdot \color{blue}{\mathsf{fma}\left(\varepsilon, \frac{1}{6} \cdot \varepsilon, -1\right)}\right) \]
              5. Applied rewrites99.5%

                \[\leadsto \color{blue}{\varepsilon \cdot \mathsf{fma}\left(\varepsilon, -0.5 \cdot \cos x, \sin x \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.16666666666666666, -1\right)\right)} \]
              6. Taylor expanded in x around 0

                \[\leadsto \frac{-1}{2} \cdot {\varepsilon}^{2} + \color{blue}{x \cdot \left(\varepsilon \cdot \left(\frac{1}{6} \cdot {\varepsilon}^{2} - 1\right) + x \cdot \left(\frac{-1}{6} \cdot \left(\varepsilon \cdot \left(x \cdot \left(\frac{1}{6} \cdot {\varepsilon}^{2} - 1\right)\right)\right) + \frac{1}{4} \cdot {\varepsilon}^{2}\right)\right)} \]
              7. Applied rewrites98.5%

                \[\leadsto \mathsf{fma}\left(x \cdot x, \color{blue}{\varepsilon \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(0.16666666666666666, \varepsilon \cdot \varepsilon, -1\right) \cdot -0.16666666666666666, \varepsilon \cdot 0.25\right)}, \varepsilon \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(0.16666666666666666, \varepsilon \cdot \varepsilon, -1\right), \varepsilon \cdot -0.5\right)\right) \]
              8. Final simplification98.5%

                \[\leadsto \mathsf{fma}\left(x \cdot x, \varepsilon \cdot \mathsf{fma}\left(x, -0.16666666666666666 \cdot \mathsf{fma}\left(0.16666666666666666, \varepsilon \cdot \varepsilon, -1\right), \varepsilon \cdot 0.25\right), \varepsilon \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(0.16666666666666666, \varepsilon \cdot \varepsilon, -1\right), \varepsilon \cdot -0.5\right)\right) \]
              9. Add Preprocessing

              Alternative 8: 98.2% accurate, 3.4× speedup?

              \[\begin{array}{l} \\ \begin{array}{l} t_0 := \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.16666666666666666, -1\right)\\ \varepsilon \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(\varepsilon, 0.25, x \cdot \left(-0.16666666666666666 \cdot t\_0\right)\right), t\_0\right), \varepsilon \cdot -0.5\right) \end{array} \end{array} \]
              (FPCore (x eps)
               :precision binary64
               (let* ((t_0 (fma eps (* eps 0.16666666666666666) -1.0)))
                 (*
                  eps
                  (fma
                   x
                   (fma x (fma eps 0.25 (* x (* -0.16666666666666666 t_0))) t_0)
                   (* eps -0.5)))))
              double code(double x, double eps) {
              	double t_0 = fma(eps, (eps * 0.16666666666666666), -1.0);
              	return eps * fma(x, fma(x, fma(eps, 0.25, (x * (-0.16666666666666666 * t_0))), t_0), (eps * -0.5));
              }
              
              function code(x, eps)
              	t_0 = fma(eps, Float64(eps * 0.16666666666666666), -1.0)
              	return Float64(eps * fma(x, fma(x, fma(eps, 0.25, Float64(x * Float64(-0.16666666666666666 * t_0))), t_0), Float64(eps * -0.5)))
              end
              
              code[x_, eps_] := Block[{t$95$0 = N[(eps * N[(eps * 0.16666666666666666), $MachinePrecision] + -1.0), $MachinePrecision]}, N[(eps * N[(x * N[(x * N[(eps * 0.25 + N[(x * N[(-0.16666666666666666 * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$0), $MachinePrecision] + N[(eps * -0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
              
              \begin{array}{l}
              
              \\
              \begin{array}{l}
              t_0 := \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.16666666666666666, -1\right)\\
              \varepsilon \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(\varepsilon, 0.25, x \cdot \left(-0.16666666666666666 \cdot t\_0\right)\right), t\_0\right), \varepsilon \cdot -0.5\right)
              \end{array}
              \end{array}
              
              Derivation
              1. Initial program 52.2%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                  \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \frac{-1}{2} \cdot \cos x, \sin x \cdot \color{blue}{\mathsf{fma}\left(\varepsilon, \frac{1}{6} \cdot \varepsilon, -1\right)}\right) \]
              5. Applied rewrites99.5%

                \[\leadsto \color{blue}{\varepsilon \cdot \mathsf{fma}\left(\varepsilon, -0.5 \cdot \cos x, \sin x \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.16666666666666666, -1\right)\right)} \]
              6. Taylor expanded in x around 0

                \[\leadsto \varepsilon \cdot \left(\frac{-1}{2} \cdot \varepsilon + \color{blue}{x \cdot \left(\left(\frac{1}{6} \cdot {\varepsilon}^{2} + \frac{1}{4} \cdot \left(\varepsilon \cdot x\right)\right) - 1\right)}\right) \]
              7. Step-by-step derivation
                1. Applied rewrites98.2%

                  \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \color{blue}{-0.5}, x \cdot \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(\varepsilon, 0.16666666666666666, x \cdot 0.25\right), -1\right)\right) \]
                2. Taylor expanded in x around 0

                  \[\leadsto \varepsilon \cdot \left(\frac{-1}{2} \cdot \varepsilon + \color{blue}{x \cdot \left(\left(\frac{1}{6} \cdot {\varepsilon}^{2} + x \cdot \left(\frac{-1}{6} \cdot \left(x \cdot \left(\frac{1}{6} \cdot {\varepsilon}^{2} - 1\right)\right) + \frac{1}{4} \cdot \varepsilon\right)\right) - 1\right)}\right) \]
                3. Step-by-step derivation
                  1. Applied rewrites98.5%

                    \[\leadsto \varepsilon \cdot \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, \mathsf{fma}\left(\varepsilon, 0.25, x \cdot \left(\mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.16666666666666666, -1\right) \cdot -0.16666666666666666\right)\right), \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.16666666666666666, -1\right)\right)}, \varepsilon \cdot -0.5\right) \]
                  2. Final simplification98.5%

                    \[\leadsto \varepsilon \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(\varepsilon, 0.25, x \cdot \left(-0.16666666666666666 \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.16666666666666666, -1\right)\right)\right), \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.16666666666666666, -1\right)\right), \varepsilon \cdot -0.5\right) \]
                  3. Add Preprocessing

                  Alternative 9: 98.2% accurate, 3.4× speedup?

                  \[\begin{array}{l} \\ \varepsilon \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, x \cdot \left(-0.16666666666666666 \cdot \mathsf{fma}\left(0.16666666666666666, \varepsilon \cdot \varepsilon, -1\right)\right), \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(\varepsilon, 0.16666666666666666, x \cdot 0.25\right), -1\right)\right), \varepsilon \cdot -0.5\right) \end{array} \]
                  (FPCore (x eps)
                   :precision binary64
                   (*
                    eps
                    (fma
                     x
                     (fma
                      x
                      (* x (* -0.16666666666666666 (fma 0.16666666666666666 (* eps eps) -1.0)))
                      (fma eps (fma eps 0.16666666666666666 (* x 0.25)) -1.0))
                     (* eps -0.5))))
                  double code(double x, double eps) {
                  	return eps * fma(x, fma(x, (x * (-0.16666666666666666 * fma(0.16666666666666666, (eps * eps), -1.0))), fma(eps, fma(eps, 0.16666666666666666, (x * 0.25)), -1.0)), (eps * -0.5));
                  }
                  
                  function code(x, eps)
                  	return Float64(eps * fma(x, fma(x, Float64(x * Float64(-0.16666666666666666 * fma(0.16666666666666666, Float64(eps * eps), -1.0))), fma(eps, fma(eps, 0.16666666666666666, Float64(x * 0.25)), -1.0)), Float64(eps * -0.5)))
                  end
                  
                  code[x_, eps_] := N[(eps * N[(x * N[(x * N[(x * N[(-0.16666666666666666 * N[(0.16666666666666666 * N[(eps * eps), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(eps * N[(eps * 0.16666666666666666 + N[(x * 0.25), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision] + N[(eps * -0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
                  
                  \begin{array}{l}
                  
                  \\
                  \varepsilon \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, x \cdot \left(-0.16666666666666666 \cdot \mathsf{fma}\left(0.16666666666666666, \varepsilon \cdot \varepsilon, -1\right)\right), \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(\varepsilon, 0.16666666666666666, x \cdot 0.25\right), -1\right)\right), \varepsilon \cdot -0.5\right)
                  \end{array}
                  
                  Derivation
                  1. Initial program 52.2%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                      \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \frac{-1}{2} \cdot \cos x, \sin x \cdot \color{blue}{\mathsf{fma}\left(\varepsilon, \frac{1}{6} \cdot \varepsilon, -1\right)}\right) \]
                  5. Applied rewrites99.5%

                    \[\leadsto \color{blue}{\varepsilon \cdot \mathsf{fma}\left(\varepsilon, -0.5 \cdot \cos x, \sin x \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.16666666666666666, -1\right)\right)} \]
                  6. Taylor expanded in x around 0

                    \[\leadsto \varepsilon \cdot \left(\frac{-1}{2} \cdot \varepsilon + \color{blue}{x \cdot \left(\left(\frac{1}{6} \cdot {\varepsilon}^{2} + x \cdot \left(\frac{-1}{6} \cdot \left(x \cdot \left(\frac{1}{6} \cdot {\varepsilon}^{2} - 1\right)\right) + \frac{1}{4} \cdot \varepsilon\right)\right) - 1\right)}\right) \]
                  7. Step-by-step derivation
                    1. Applied rewrites98.5%

                      \[\leadsto \varepsilon \cdot \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, x \cdot \left(\mathsf{fma}\left(0.16666666666666666, \varepsilon \cdot \varepsilon, -1\right) \cdot -0.16666666666666666\right), \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(\varepsilon, 0.16666666666666666, x \cdot 0.25\right), -1\right)\right)}, \varepsilon \cdot -0.5\right) \]
                    2. Final simplification98.5%

                      \[\leadsto \varepsilon \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, x \cdot \left(-0.16666666666666666 \cdot \mathsf{fma}\left(0.16666666666666666, \varepsilon \cdot \varepsilon, -1\right)\right), \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(\varepsilon, 0.16666666666666666, x \cdot 0.25\right), -1\right)\right), \varepsilon \cdot -0.5\right) \]
                    3. Add Preprocessing

                    Alternative 10: 97.7% accurate, 8.3× speedup?

                    \[\begin{array}{l} \\ \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(0.16666666666666666, \varepsilon \cdot x, -0.5\right), -x\right) \end{array} \]
                    (FPCore (x eps)
                     :precision binary64
                     (* eps (fma eps (fma 0.16666666666666666 (* eps x) -0.5) (- x))))
                    double code(double x, double eps) {
                    	return eps * fma(eps, fma(0.16666666666666666, (eps * x), -0.5), -x);
                    }
                    
                    function code(x, eps)
                    	return Float64(eps * fma(eps, fma(0.16666666666666666, Float64(eps * x), -0.5), Float64(-x)))
                    end
                    
                    code[x_, eps_] := N[(eps * N[(eps * N[(0.16666666666666666 * N[(eps * x), $MachinePrecision] + -0.5), $MachinePrecision] + (-x)), $MachinePrecision]), $MachinePrecision]
                    
                    \begin{array}{l}
                    
                    \\
                    \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(0.16666666666666666, \varepsilon \cdot x, -0.5\right), -x\right)
                    \end{array}
                    
                    Derivation
                    1. Initial program 52.2%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                        \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \frac{-1}{2} \cdot \cos x, \sin x \cdot \color{blue}{\mathsf{fma}\left(\varepsilon, \frac{1}{6} \cdot \varepsilon, -1\right)}\right) \]
                    5. Applied rewrites99.5%

                      \[\leadsto \color{blue}{\varepsilon \cdot \mathsf{fma}\left(\varepsilon, -0.5 \cdot \cos x, \sin x \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.16666666666666666, -1\right)\right)} \]
                    6. Taylor expanded in x around 0

                      \[\leadsto \varepsilon \cdot \left(\frac{-1}{2} \cdot \varepsilon + \color{blue}{x \cdot \left(\left(\frac{1}{6} \cdot {\varepsilon}^{2} + \frac{1}{4} \cdot \left(\varepsilon \cdot x\right)\right) - 1\right)}\right) \]
                    7. Step-by-step derivation
                      1. Applied rewrites98.2%

                        \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \color{blue}{-0.5}, x \cdot \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(\varepsilon, 0.16666666666666666, x \cdot 0.25\right), -1\right)\right) \]
                      2. Taylor expanded in x around 0

                        \[\leadsto \varepsilon \cdot \left(\frac{-1}{2} \cdot \varepsilon + \color{blue}{x \cdot \left(\frac{1}{6} \cdot {\varepsilon}^{2} - 1\right)}\right) \]
                      3. Step-by-step derivation
                        1. Applied rewrites98.2%

                          \[\leadsto \varepsilon \cdot \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.16666666666666666, -1\right)}, \varepsilon \cdot -0.5\right) \]
                        2. Taylor expanded in eps around 0

                          \[\leadsto \varepsilon \cdot \left(-1 \cdot x + \varepsilon \cdot \color{blue}{\left(\frac{1}{6} \cdot \left(\varepsilon \cdot x\right) - \frac{1}{2}\right)}\right) \]
                        3. Step-by-step derivation
                          1. Applied rewrites98.2%

                            \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(0.16666666666666666, \color{blue}{\varepsilon \cdot x}, -0.5\right), -x\right) \]
                          2. Add Preprocessing

                          Alternative 11: 97.7% accurate, 14.8× speedup?

                          \[\begin{array}{l} \\ \varepsilon \cdot \mathsf{fma}\left(\varepsilon, -0.5, -x\right) \end{array} \]
                          (FPCore (x eps) :precision binary64 (* eps (fma eps -0.5 (- x))))
                          double code(double x, double eps) {
                          	return eps * fma(eps, -0.5, -x);
                          }
                          
                          function code(x, eps)
                          	return Float64(eps * fma(eps, -0.5, Float64(-x)))
                          end
                          
                          code[x_, eps_] := N[(eps * N[(eps * -0.5 + (-x)), $MachinePrecision]), $MachinePrecision]
                          
                          \begin{array}{l}
                          
                          \\
                          \varepsilon \cdot \mathsf{fma}\left(\varepsilon, -0.5, -x\right)
                          \end{array}
                          
                          Derivation
                          1. Initial program 52.2%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                              \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \frac{-1}{2} \cdot \cos x, \sin x \cdot \color{blue}{\mathsf{fma}\left(\varepsilon, \frac{1}{6} \cdot \varepsilon, -1\right)}\right) \]
                          5. Applied rewrites99.5%

                            \[\leadsto \color{blue}{\varepsilon \cdot \mathsf{fma}\left(\varepsilon, -0.5 \cdot \cos x, \sin x \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.16666666666666666, -1\right)\right)} \]
                          6. Taylor expanded in x around 0

                            \[\leadsto \varepsilon \cdot \left(\frac{-1}{2} \cdot \varepsilon + \color{blue}{x \cdot \left(\left(\frac{1}{6} \cdot {\varepsilon}^{2} + \frac{1}{4} \cdot \left(\varepsilon \cdot x\right)\right) - 1\right)}\right) \]
                          7. Step-by-step derivation
                            1. Applied rewrites98.2%

                              \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \color{blue}{-0.5}, x \cdot \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(\varepsilon, 0.16666666666666666, x \cdot 0.25\right), -1\right)\right) \]
                            2. Taylor expanded in eps around 0

                              \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \frac{-1}{2}, -1 \cdot x\right) \]
                            3. Step-by-step derivation
                              1. Applied rewrites98.2%

                                \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, -0.5, -x\right) \]
                              2. Add Preprocessing

                              Alternative 12: 78.2% accurate, 25.9× 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 52.2%

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

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

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

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

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

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

                                  \[\leadsto \sin x \cdot \color{blue}{\left(\mathsf{neg}\left(\varepsilon\right)\right)} \]
                                6. lower-neg.f6480.4

                                  \[\leadsto \sin x \cdot \color{blue}{\left(-\varepsilon\right)} \]
                              5. Applied rewrites80.4%

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

                                \[\leadsto -1 \cdot \color{blue}{\left(\varepsilon \cdot x\right)} \]
                              7. Step-by-step derivation
                                1. Applied rewrites79.7%

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

                                Alternative 13: 50.8% accurate, 51.8× speedup?

                                \[\begin{array}{l} \\ -1 + 1 \end{array} \]
                                (FPCore (x eps) :precision binary64 (+ -1.0 1.0))
                                double code(double x, double eps) {
                                	return -1.0 + 1.0;
                                }
                                
                                real(8) function code(x, eps)
                                    real(8), intent (in) :: x
                                    real(8), intent (in) :: eps
                                    code = (-1.0d0) + 1.0d0
                                end function
                                
                                public static double code(double x, double eps) {
                                	return -1.0 + 1.0;
                                }
                                
                                def code(x, eps):
                                	return -1.0 + 1.0
                                
                                function code(x, eps)
                                	return Float64(-1.0 + 1.0)
                                end
                                
                                function tmp = code(x, eps)
                                	tmp = -1.0 + 1.0;
                                end
                                
                                code[x_, eps_] := N[(-1.0 + 1.0), $MachinePrecision]
                                
                                \begin{array}{l}
                                
                                \\
                                -1 + 1
                                \end{array}
                                
                                Derivation
                                1. Initial program 52.2%

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

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

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

                                    \[\leadsto \cos \varepsilon + \color{blue}{-1} \]
                                  3. lower-+.f64N/A

                                    \[\leadsto \color{blue}{\cos \varepsilon + -1} \]
                                  4. lower-cos.f6451.2

                                    \[\leadsto \color{blue}{\cos \varepsilon} + -1 \]
                                5. Applied rewrites51.2%

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

                                  \[\leadsto 1 + -1 \]
                                7. Step-by-step derivation
                                  1. Applied rewrites51.1%

                                    \[\leadsto 1 + -1 \]
                                  2. Final simplification51.1%

                                    \[\leadsto -1 + 1 \]
                                  3. Add Preprocessing

                                  Developer Target 1: 99.7% accurate, 0.9× speedup?

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

                                  Developer Target 2: 98.7% accurate, 0.5× speedup?

                                  \[\begin{array}{l} \\ {\left(\sqrt[3]{\left(-2 \cdot \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)\right) \cdot \sin \left(0.5 \cdot \varepsilon\right)}\right)}^{3} \end{array} \]
                                  (FPCore (x eps)
                                   :precision binary64
                                   (pow (cbrt (* (* -2.0 (sin (* 0.5 (fma 2.0 x eps)))) (sin (* 0.5 eps)))) 3.0))
                                  double code(double x, double eps) {
                                  	return pow(cbrt(((-2.0 * sin((0.5 * fma(2.0, x, eps)))) * sin((0.5 * eps)))), 3.0);
                                  }
                                  
                                  function code(x, eps)
                                  	return cbrt(Float64(Float64(-2.0 * sin(Float64(0.5 * fma(2.0, x, eps)))) * sin(Float64(0.5 * eps)))) ^ 3.0
                                  end
                                  
                                  code[x_, eps_] := N[Power[N[Power[N[(N[(-2.0 * N[Sin[N[(0.5 * N[(2.0 * x + eps), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[Sin[N[(0.5 * eps), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision], 3.0], $MachinePrecision]
                                  
                                  \begin{array}{l}
                                  
                                  \\
                                  {\left(\sqrt[3]{\left(-2 \cdot \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)\right) \cdot \sin \left(0.5 \cdot \varepsilon\right)}\right)}^{3}
                                  \end{array}
                                  

                                  Reproduce

                                  ?
                                  herbie shell --seed 2024238 
                                  (FPCore (x eps)
                                    :name "2cos (problem 3.3.5)"
                                    :precision binary64
                                    :pre (and (and (and (<= -10000.0 x) (<= x 10000.0)) (< (* 1e-16 (fabs x)) eps)) (< eps (fabs x)))
                                  
                                    :alt
                                    (! :herbie-platform default (* -2 (sin (+ x (/ eps 2))) (sin (/ eps 2))))
                                  
                                    :alt
                                    (! :herbie-platform default (pow (cbrt (* -2 (sin (* 1/2 (fma 2 x eps))) (sin (* 1/2 eps)))) 3))
                                  
                                    (- (cos (+ x eps)) (cos x)))