2cos (problem 3.3.5)

Percentage Accurate: 52.2% → 99.8%
Time: 15.2s
Alternatives: 11
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 11 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: 52.2% 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: 99.8% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sin \left(0.5 \cdot \varepsilon\right)\\ \left(\mathsf{fma}\left(t\_0, \cos x, \cos \left(0.5 \cdot \varepsilon\right) \cdot \sin x\right) \cdot t\_0\right) \cdot -2 \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (sin (* 0.5 eps))))
   (* (* (fma t_0 (cos x) (* (cos (* 0.5 eps)) (sin x))) t_0) -2.0)))
double code(double x, double eps) {
	double t_0 = sin((0.5 * eps));
	return (fma(t_0, cos(x), (cos((0.5 * eps)) * sin(x))) * t_0) * -2.0;
}
function code(x, eps)
	t_0 = sin(Float64(0.5 * eps))
	return Float64(Float64(fma(t_0, cos(x), Float64(cos(Float64(0.5 * eps)) * sin(x))) * t_0) * -2.0)
end
code[x_, eps_] := Block[{t$95$0 = N[Sin[N[(0.5 * eps), $MachinePrecision]], $MachinePrecision]}, N[(N[(N[(t$95$0 * N[Cos[x], $MachinePrecision] + N[(N[Cos[N[(0.5 * eps), $MachinePrecision]], $MachinePrecision] * N[Sin[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * t$95$0), $MachinePrecision] * -2.0), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sin \left(0.5 \cdot \varepsilon\right)\\
\left(\mathsf{fma}\left(t\_0, \cos x, \cos \left(0.5 \cdot \varepsilon\right) \cdot \sin x\right) \cdot t\_0\right) \cdot -2
\end{array}
\end{array}
Derivation
  1. Initial program 49.1%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  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 rewrites78.4%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    Alternative 2: 99.7% accurate, 0.9× speedup?

    \[\begin{array}{l} \\ \left(\sin \left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right) \cdot \sin \left(0.5 \cdot \varepsilon\right)\right) \cdot -2 \end{array} \]
    (FPCore (x eps)
     :precision binary64
     (* (* (sin (fma 0.5 eps x)) (sin (* 0.5 eps))) -2.0))
    double code(double x, double eps) {
    	return (sin(fma(0.5, eps, x)) * sin((0.5 * eps))) * -2.0;
    }
    
    function code(x, eps)
    	return Float64(Float64(sin(fma(0.5, eps, x)) * sin(Float64(0.5 * eps))) * -2.0)
    end
    
    code[x_, eps_] := N[(N[(N[Sin[N[(0.5 * eps + x), $MachinePrecision]], $MachinePrecision] * N[Sin[N[(0.5 * eps), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * -2.0), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \left(\sin \left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right) \cdot \sin \left(0.5 \cdot \varepsilon\right)\right) \cdot -2
    \end{array}
    
    Derivation
    1. Initial program 49.1%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    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 rewrites78.4%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    Alternative 3: 99.3% accurate, 0.9× speedup?

    \[\begin{array}{l} \\ \mathsf{fma}\left(\cos x \cdot \varepsilon, 0.5, \sin x\right) \cdot \left(-\varepsilon\right) \end{array} \]
    (FPCore (x eps)
     :precision binary64
     (* (fma (* (cos x) eps) 0.5 (sin x)) (- eps)))
    double code(double x, double eps) {
    	return fma((cos(x) * eps), 0.5, sin(x)) * -eps;
    }
    
    function code(x, eps)
    	return Float64(fma(Float64(cos(x) * eps), 0.5, sin(x)) * Float64(-eps))
    end
    
    code[x_, eps_] := N[(N[(N[(N[Cos[x], $MachinePrecision] * eps), $MachinePrecision] * 0.5 + N[Sin[x], $MachinePrecision]), $MachinePrecision] * (-eps)), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \mathsf{fma}\left(\cos x \cdot \varepsilon, 0.5, \sin x\right) \cdot \left(-\varepsilon\right)
    \end{array}
    
    Derivation
    1. Initial program 49.1%

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

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

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

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

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

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

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

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

    Alternative 4: 98.9% accurate, 1.3× speedup?

    \[\begin{array}{l} \\ \left(\mathsf{fma}\left(\mathsf{fma}\left(\left(\left(0.041666666666666664 \cdot \left(\varepsilon \cdot \varepsilon\right) - 0.5\right) \cdot \varepsilon\right) \cdot x, -0.5, \left(\varepsilon \cdot \varepsilon\right) \cdot 0.16666666666666666\right), x, -0.5 \cdot \varepsilon\right) - \sin x\right) \cdot \varepsilon \end{array} \]
    (FPCore (x eps)
     :precision binary64
     (*
      (-
       (fma
        (fma
         (* (* (- (* 0.041666666666666664 (* eps eps)) 0.5) eps) x)
         -0.5
         (* (* eps eps) 0.16666666666666666))
        x
        (* -0.5 eps))
       (sin x))
      eps))
    double code(double x, double eps) {
    	return (fma(fma(((((0.041666666666666664 * (eps * eps)) - 0.5) * eps) * x), -0.5, ((eps * eps) * 0.16666666666666666)), x, (-0.5 * eps)) - sin(x)) * eps;
    }
    
    function code(x, eps)
    	return Float64(Float64(fma(fma(Float64(Float64(Float64(Float64(0.041666666666666664 * Float64(eps * eps)) - 0.5) * eps) * x), -0.5, Float64(Float64(eps * eps) * 0.16666666666666666)), x, Float64(-0.5 * eps)) - sin(x)) * eps)
    end
    
    code[x_, eps_] := N[(N[(N[(N[(N[(N[(N[(N[(0.041666666666666664 * N[(eps * eps), $MachinePrecision]), $MachinePrecision] - 0.5), $MachinePrecision] * eps), $MachinePrecision] * x), $MachinePrecision] * -0.5 + N[(N[(eps * eps), $MachinePrecision] * 0.16666666666666666), $MachinePrecision]), $MachinePrecision] * x + N[(-0.5 * eps), $MachinePrecision]), $MachinePrecision] - N[Sin[x], $MachinePrecision]), $MachinePrecision] * eps), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \left(\mathsf{fma}\left(\mathsf{fma}\left(\left(\left(0.041666666666666664 \cdot \left(\varepsilon \cdot \varepsilon\right) - 0.5\right) \cdot \varepsilon\right) \cdot x, -0.5, \left(\varepsilon \cdot \varepsilon\right) \cdot 0.16666666666666666\right), x, -0.5 \cdot \varepsilon\right) - \sin x\right) \cdot \varepsilon
    \end{array}
    
    Derivation
    1. Initial program 49.1%

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

      \[\leadsto \color{blue}{\varepsilon \cdot \left(\varepsilon \cdot \left(\frac{-1}{2} \cdot \cos x + \varepsilon \cdot \left(\frac{1}{24} \cdot \left(\varepsilon \cdot \cos x\right) - \frac{-1}{6} \cdot \sin x\right)\right) - \sin x\right)} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \color{blue}{\left(\varepsilon \cdot \left(\frac{-1}{2} \cdot \cos x + \varepsilon \cdot \left(\frac{1}{24} \cdot \left(\varepsilon \cdot \cos x\right) - \frac{-1}{6} \cdot \sin x\right)\right) - \sin x\right) \cdot \varepsilon} \]
      2. lower-*.f64N/A

        \[\leadsto \color{blue}{\left(\varepsilon \cdot \left(\frac{-1}{2} \cdot \cos x + \varepsilon \cdot \left(\frac{1}{24} \cdot \left(\varepsilon \cdot \cos x\right) - \frac{-1}{6} \cdot \sin x\right)\right) - \sin x\right) \cdot \varepsilon} \]
    5. Applied rewrites99.6%

      \[\leadsto \color{blue}{\left(\mathsf{fma}\left(\cos x, \mathsf{fma}\left(\varepsilon, 0.041666666666666664 \cdot \varepsilon, -0.5\right), \left(\sin x \cdot \varepsilon\right) \cdot 0.16666666666666666\right) \cdot \varepsilon - \sin x\right) \cdot \varepsilon} \]
    6. Taylor expanded in x around 0

      \[\leadsto \left(\left(\varepsilon \cdot \left(\frac{1}{24} \cdot {\varepsilon}^{2} - \frac{1}{2}\right) + x \cdot \left(\frac{-1}{2} \cdot \left(\varepsilon \cdot \left(x \cdot \left(\frac{1}{24} \cdot {\varepsilon}^{2} - \frac{1}{2}\right)\right)\right) + \frac{1}{6} \cdot {\varepsilon}^{2}\right)\right) - \sin x\right) \cdot \varepsilon \]
    7. Step-by-step derivation
      1. Applied rewrites98.4%

        \[\leadsto \left(\mathsf{fma}\left(\mathsf{fma}\left(\left(\left(0.041666666666666664 \cdot \left(\varepsilon \cdot \varepsilon\right) - 0.5\right) \cdot \varepsilon\right) \cdot x, -0.5, \left(\varepsilon \cdot \varepsilon\right) \cdot 0.16666666666666666\right), x, \left(0.041666666666666664 \cdot \left(\varepsilon \cdot \varepsilon\right) - 0.5\right) \cdot \varepsilon\right) - \sin x\right) \cdot \varepsilon \]
      2. Taylor expanded in eps around 0

        \[\leadsto \left(\mathsf{fma}\left(\mathsf{fma}\left(\left(\left(\frac{1}{24} \cdot \left(\varepsilon \cdot \varepsilon\right) - \frac{1}{2}\right) \cdot \varepsilon\right) \cdot x, \frac{-1}{2}, \left(\varepsilon \cdot \varepsilon\right) \cdot \frac{1}{6}\right), x, \frac{-1}{2} \cdot \varepsilon\right) - \sin x\right) \cdot \varepsilon \]
      3. Step-by-step derivation
        1. Applied rewrites98.4%

          \[\leadsto \left(\mathsf{fma}\left(\mathsf{fma}\left(\left(\left(0.041666666666666664 \cdot \left(\varepsilon \cdot \varepsilon\right) - 0.5\right) \cdot \varepsilon\right) \cdot x, -0.5, \left(\varepsilon \cdot \varepsilon\right) \cdot 0.16666666666666666\right), x, -0.5 \cdot \varepsilon\right) - \sin x\right) \cdot \varepsilon \]
        2. Add Preprocessing

        Alternative 5: 98.9% accurate, 1.5× speedup?

        \[\begin{array}{l} \\ \left(\mathsf{fma}\left(0.16666666666666666 \cdot \varepsilon, x, 0.25 \cdot \left(x \cdot x\right) - 0.5\right) \cdot \varepsilon - \sin x\right) \cdot \varepsilon \end{array} \]
        (FPCore (x eps)
         :precision binary64
         (*
          (-
           (* (fma (* 0.16666666666666666 eps) x (- (* 0.25 (* x x)) 0.5)) eps)
           (sin x))
          eps))
        double code(double x, double eps) {
        	return ((fma((0.16666666666666666 * eps), x, ((0.25 * (x * x)) - 0.5)) * eps) - sin(x)) * eps;
        }
        
        function code(x, eps)
        	return Float64(Float64(Float64(fma(Float64(0.16666666666666666 * eps), x, Float64(Float64(0.25 * Float64(x * x)) - 0.5)) * eps) - sin(x)) * eps)
        end
        
        code[x_, eps_] := N[(N[(N[(N[(N[(0.16666666666666666 * eps), $MachinePrecision] * x + N[(N[(0.25 * N[(x * x), $MachinePrecision]), $MachinePrecision] - 0.5), $MachinePrecision]), $MachinePrecision] * eps), $MachinePrecision] - N[Sin[x], $MachinePrecision]), $MachinePrecision] * eps), $MachinePrecision]
        
        \begin{array}{l}
        
        \\
        \left(\mathsf{fma}\left(0.16666666666666666 \cdot \varepsilon, x, 0.25 \cdot \left(x \cdot x\right) - 0.5\right) \cdot \varepsilon - \sin x\right) \cdot \varepsilon
        \end{array}
        
        Derivation
        1. Initial program 49.1%

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

          \[\leadsto \color{blue}{\varepsilon \cdot \left(\varepsilon \cdot \left(\frac{-1}{2} \cdot \cos x + \varepsilon \cdot \left(\frac{1}{24} \cdot \left(\varepsilon \cdot \cos x\right) - \frac{-1}{6} \cdot \sin x\right)\right) - \sin x\right)} \]
        4. Step-by-step derivation
          1. *-commutativeN/A

            \[\leadsto \color{blue}{\left(\varepsilon \cdot \left(\frac{-1}{2} \cdot \cos x + \varepsilon \cdot \left(\frac{1}{24} \cdot \left(\varepsilon \cdot \cos x\right) - \frac{-1}{6} \cdot \sin x\right)\right) - \sin x\right) \cdot \varepsilon} \]
          2. lower-*.f64N/A

            \[\leadsto \color{blue}{\left(\varepsilon \cdot \left(\frac{-1}{2} \cdot \cos x + \varepsilon \cdot \left(\frac{1}{24} \cdot \left(\varepsilon \cdot \cos x\right) - \frac{-1}{6} \cdot \sin x\right)\right) - \sin x\right) \cdot \varepsilon} \]
        5. Applied rewrites99.6%

          \[\leadsto \color{blue}{\left(\mathsf{fma}\left(\cos x, \mathsf{fma}\left(\varepsilon, 0.041666666666666664 \cdot \varepsilon, -0.5\right), \left(\sin x \cdot \varepsilon\right) \cdot 0.16666666666666666\right) \cdot \varepsilon - \sin x\right) \cdot \varepsilon} \]
        6. Taylor expanded in x around 0

          \[\leadsto \left(\left(\varepsilon \cdot \left(\frac{1}{24} \cdot {\varepsilon}^{2} - \frac{1}{2}\right) + x \cdot \left(\frac{-1}{2} \cdot \left(\varepsilon \cdot \left(x \cdot \left(\frac{1}{24} \cdot {\varepsilon}^{2} - \frac{1}{2}\right)\right)\right) + \frac{1}{6} \cdot {\varepsilon}^{2}\right)\right) - \sin x\right) \cdot \varepsilon \]
        7. Step-by-step derivation
          1. Applied rewrites98.4%

            \[\leadsto \left(\mathsf{fma}\left(\mathsf{fma}\left(\left(\left(0.041666666666666664 \cdot \left(\varepsilon \cdot \varepsilon\right) - 0.5\right) \cdot \varepsilon\right) \cdot x, -0.5, \left(\varepsilon \cdot \varepsilon\right) \cdot 0.16666666666666666\right), x, \left(0.041666666666666664 \cdot \left(\varepsilon \cdot \varepsilon\right) - 0.5\right) \cdot \varepsilon\right) - \sin x\right) \cdot \varepsilon \]
          2. Taylor expanded in eps around 0

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

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

            Alternative 6: 98.9% accurate, 1.8× speedup?

            \[\begin{array}{l} \\ \left(-0.5 \cdot \varepsilon - \sin x\right) \cdot \varepsilon \end{array} \]
            (FPCore (x eps) :precision binary64 (* (- (* -0.5 eps) (sin x)) eps))
            double code(double x, double eps) {
            	return ((-0.5 * eps) - sin(x)) * eps;
            }
            
            real(8) function code(x, eps)
                real(8), intent (in) :: x
                real(8), intent (in) :: eps
                code = (((-0.5d0) * eps) - sin(x)) * eps
            end function
            
            public static double code(double x, double eps) {
            	return ((-0.5 * eps) - Math.sin(x)) * eps;
            }
            
            def code(x, eps):
            	return ((-0.5 * eps) - math.sin(x)) * eps
            
            function code(x, eps)
            	return Float64(Float64(Float64(-0.5 * eps) - sin(x)) * eps)
            end
            
            function tmp = code(x, eps)
            	tmp = ((-0.5 * eps) - sin(x)) * eps;
            end
            
            code[x_, eps_] := N[(N[(N[(-0.5 * eps), $MachinePrecision] - N[Sin[x], $MachinePrecision]), $MachinePrecision] * eps), $MachinePrecision]
            
            \begin{array}{l}
            
            \\
            \left(-0.5 \cdot \varepsilon - \sin x\right) \cdot \varepsilon
            \end{array}
            
            Derivation
            1. Initial program 49.1%

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

              \[\leadsto \color{blue}{\varepsilon \cdot \left(\varepsilon \cdot \left(\frac{-1}{2} \cdot \cos x + \varepsilon \cdot \left(\frac{1}{24} \cdot \left(\varepsilon \cdot \cos x\right) - \frac{-1}{6} \cdot \sin x\right)\right) - \sin x\right)} \]
            4. Step-by-step derivation
              1. *-commutativeN/A

                \[\leadsto \color{blue}{\left(\varepsilon \cdot \left(\frac{-1}{2} \cdot \cos x + \varepsilon \cdot \left(\frac{1}{24} \cdot \left(\varepsilon \cdot \cos x\right) - \frac{-1}{6} \cdot \sin x\right)\right) - \sin x\right) \cdot \varepsilon} \]
              2. lower-*.f64N/A

                \[\leadsto \color{blue}{\left(\varepsilon \cdot \left(\frac{-1}{2} \cdot \cos x + \varepsilon \cdot \left(\frac{1}{24} \cdot \left(\varepsilon \cdot \cos x\right) - \frac{-1}{6} \cdot \sin x\right)\right) - \sin x\right) \cdot \varepsilon} \]
            5. Applied rewrites99.6%

              \[\leadsto \color{blue}{\left(\mathsf{fma}\left(\cos x, \mathsf{fma}\left(\varepsilon, 0.041666666666666664 \cdot \varepsilon, -0.5\right), \left(\sin x \cdot \varepsilon\right) \cdot 0.16666666666666666\right) \cdot \varepsilon - \sin x\right) \cdot \varepsilon} \]
            6. Taylor expanded in x around 0

              \[\leadsto \left(\left(\frac{1}{6} \cdot \left({\varepsilon}^{2} \cdot x\right) + \varepsilon \cdot \left(\frac{1}{24} \cdot {\varepsilon}^{2} - \frac{1}{2}\right)\right) - \sin x\right) \cdot \varepsilon \]
            7. Step-by-step derivation
              1. Applied rewrites98.3%

                \[\leadsto \left(\mathsf{fma}\left(\left(\varepsilon \cdot \varepsilon\right) \cdot x, 0.16666666666666666, \left(0.041666666666666664 \cdot \left(\varepsilon \cdot \varepsilon\right) - 0.5\right) \cdot \varepsilon\right) - \sin x\right) \cdot \varepsilon \]
              2. Taylor expanded in eps around 0

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

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

                Alternative 7: 98.3% accurate, 5.8× speedup?

                \[\begin{array}{l} \\ \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.25, \varepsilon, -0.16666666666666666 \cdot x\right), x, 1\right), x, 0.5 \cdot \varepsilon\right) \cdot \left(-\varepsilon\right) \end{array} \]
                (FPCore (x eps)
                 :precision binary64
                 (*
                  (fma (fma (fma -0.25 eps (* -0.16666666666666666 x)) x 1.0) x (* 0.5 eps))
                  (- eps)))
                double code(double x, double eps) {
                	return fma(fma(fma(-0.25, eps, (-0.16666666666666666 * x)), x, 1.0), x, (0.5 * eps)) * -eps;
                }
                
                function code(x, eps)
                	return Float64(fma(fma(fma(-0.25, eps, Float64(-0.16666666666666666 * x)), x, 1.0), x, Float64(0.5 * eps)) * Float64(-eps))
                end
                
                code[x_, eps_] := N[(N[(N[(N[(-0.25 * eps + N[(-0.16666666666666666 * x), $MachinePrecision]), $MachinePrecision] * x + 1.0), $MachinePrecision] * x + N[(0.5 * eps), $MachinePrecision]), $MachinePrecision] * (-eps)), $MachinePrecision]
                
                \begin{array}{l}
                
                \\
                \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.25, \varepsilon, -0.16666666666666666 \cdot x\right), x, 1\right), x, 0.5 \cdot \varepsilon\right) \cdot \left(-\varepsilon\right)
                \end{array}
                
                Derivation
                1. Initial program 49.1%

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

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

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

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

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

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

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

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

                  \[\leadsto \left(\frac{1}{2} \cdot \varepsilon + x \cdot \left(1 + x \cdot \left(\frac{-1}{4} \cdot \varepsilon + \frac{-1}{6} \cdot x\right)\right)\right) \cdot \left(-\color{blue}{\varepsilon}\right) \]
                7. Step-by-step derivation
                  1. Applied rewrites97.2%

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

                  Alternative 8: 98.0% accurate, 10.9× speedup?

                  \[\begin{array}{l} \\ \mathsf{fma}\left(-\varepsilon, x, \left(\varepsilon \cdot \varepsilon\right) \cdot -0.5\right) \end{array} \]
                  (FPCore (x eps) :precision binary64 (fma (- eps) x (* (* eps eps) -0.5)))
                  double code(double x, double eps) {
                  	return fma(-eps, x, ((eps * eps) * -0.5));
                  }
                  
                  function code(x, eps)
                  	return fma(Float64(-eps), x, Float64(Float64(eps * eps) * -0.5))
                  end
                  
                  code[x_, eps_] := N[((-eps) * x + N[(N[(eps * eps), $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision]
                  
                  \begin{array}{l}
                  
                  \\
                  \mathsf{fma}\left(-\varepsilon, x, \left(\varepsilon \cdot \varepsilon\right) \cdot -0.5\right)
                  \end{array}
                  
                  Derivation
                  1. Initial program 49.1%

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

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

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

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

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

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

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

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

                    \[\leadsto -1 \cdot \left(\varepsilon \cdot x\right) + \color{blue}{\frac{-1}{2} \cdot {\varepsilon}^{2}} \]
                  7. Step-by-step derivation
                    1. Applied rewrites96.4%

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

                    Alternative 9: 97.8% accurate, 14.8× speedup?

                    \[\begin{array}{l} \\ \mathsf{fma}\left(0.5, \varepsilon, x\right) \cdot \left(-\varepsilon\right) \end{array} \]
                    (FPCore (x eps) :precision binary64 (* (fma 0.5 eps x) (- eps)))
                    double code(double x, double eps) {
                    	return fma(0.5, eps, x) * -eps;
                    }
                    
                    function code(x, eps)
                    	return Float64(fma(0.5, eps, x) * Float64(-eps))
                    end
                    
                    code[x_, eps_] := N[(N[(0.5 * eps + x), $MachinePrecision] * (-eps)), $MachinePrecision]
                    
                    \begin{array}{l}
                    
                    \\
                    \mathsf{fma}\left(0.5, \varepsilon, x\right) \cdot \left(-\varepsilon\right)
                    \end{array}
                    
                    Derivation
                    1. Initial program 49.1%

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

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

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

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

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

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

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

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

                      \[\leadsto \left(x + \frac{1}{2} \cdot \varepsilon\right) \cdot \left(-\color{blue}{\varepsilon}\right) \]
                    7. Step-by-step derivation
                      1. Applied rewrites96.2%

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

                      Alternative 10: 79.0% accurate, 25.9× speedup?

                      \[\begin{array}{l} \\ \left(-\varepsilon\right) \cdot x \end{array} \]
                      (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(Float64(-eps) * x)
                      end
                      
                      function tmp = code(x, eps)
                      	tmp = -eps * x;
                      end
                      
                      code[x_, eps_] := N[((-eps) * x), $MachinePrecision]
                      
                      \begin{array}{l}
                      
                      \\
                      \left(-\varepsilon\right) \cdot x
                      \end{array}
                      
                      Derivation
                      1. Initial program 49.1%

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

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

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

                          \[\leadsto \color{blue}{\left(-\varepsilon\right)} \cdot \sin x \]
                        5. lower-sin.f6478.8

                          \[\leadsto \left(-\varepsilon\right) \cdot \color{blue}{\sin x} \]
                      5. Applied rewrites78.8%

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

                        \[\leadsto -1 \cdot \color{blue}{\left(\varepsilon \cdot x\right)} \]
                      7. Step-by-step derivation
                        1. Applied rewrites77.1%

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

                        Alternative 11: 50.9% 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 49.1%

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

                          \[\leadsto \color{blue}{\cos \varepsilon - 1} \]
                        4. Step-by-step derivation
                          1. lower--.f64N/A

                            \[\leadsto \color{blue}{\cos \varepsilon - 1} \]
                          2. lower-cos.f6447.0

                            \[\leadsto \color{blue}{\cos \varepsilon} - 1 \]
                        5. Applied rewrites47.0%

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

                          \[\leadsto 1 - 1 \]
                        7. Step-by-step derivation
                          1. Applied rewrites46.9%

                            \[\leadsto 1 - 1 \]
                          2. Add Preprocessing

                          Developer Target 1: 98.8% 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 2024337 
                          (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 (pow (cbrt (* -2 (sin (* 1/2 (fma 2 x eps))) (sin (* 1/2 eps)))) 3))
                          
                            (- (cos (+ x eps)) (cos x)))