2tan (problem 3.3.2)

Percentage Accurate: 42.8% → 99.3%
Time: 18.5s
Alternatives: 16
Speedup: 2.0×

Specification

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

\\
\tan \left(x + \varepsilon\right) - \tan 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 16 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: 42.8% accurate, 1.0× speedup?

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

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

Alternative 1: 99.3% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 1 - \tan x \cdot \tan \varepsilon\\ t_1 := \tan x + \tan \varepsilon\\ t_2 := \frac{-1}{\tan x}\\ \mathbf{if}\;\varepsilon \leq -2.15 \cdot 10^{-9}:\\ \;\;\;\;\left(-\tan x\right) - \frac{t_1}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}\\ \mathbf{elif}\;\varepsilon \leq 5.2 \cdot 10^{-9}:\\ \;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{t_0 + t_1 \cdot t_2}{t_0 \cdot t_2}\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (- 1.0 (* (tan x) (tan eps))))
        (t_1 (+ (tan x) (tan eps)))
        (t_2 (/ -1.0 (tan x))))
   (if (<= eps -2.15e-9)
     (- (- (tan x)) (/ t_1 (fma (tan x) (tan eps) -1.0)))
     (if (<= eps 5.2e-9)
       (+ eps (* eps (pow (tan x) 2.0)))
       (/ (+ t_0 (* t_1 t_2)) (* t_0 t_2))))))
double code(double x, double eps) {
	double t_0 = 1.0 - (tan(x) * tan(eps));
	double t_1 = tan(x) + tan(eps);
	double t_2 = -1.0 / tan(x);
	double tmp;
	if (eps <= -2.15e-9) {
		tmp = -tan(x) - (t_1 / fma(tan(x), tan(eps), -1.0));
	} else if (eps <= 5.2e-9) {
		tmp = eps + (eps * pow(tan(x), 2.0));
	} else {
		tmp = (t_0 + (t_1 * t_2)) / (t_0 * t_2);
	}
	return tmp;
}
function code(x, eps)
	t_0 = Float64(1.0 - Float64(tan(x) * tan(eps)))
	t_1 = Float64(tan(x) + tan(eps))
	t_2 = Float64(-1.0 / tan(x))
	tmp = 0.0
	if (eps <= -2.15e-9)
		tmp = Float64(Float64(-tan(x)) - Float64(t_1 / fma(tan(x), tan(eps), -1.0)));
	elseif (eps <= 5.2e-9)
		tmp = Float64(eps + Float64(eps * (tan(x) ^ 2.0)));
	else
		tmp = Float64(Float64(t_0 + Float64(t_1 * t_2)) / Float64(t_0 * t_2));
	end
	return tmp
end
code[x_, eps_] := Block[{t$95$0 = N[(1.0 - N[(N[Tan[x], $MachinePrecision] * N[Tan[eps], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[Tan[x], $MachinePrecision] + N[Tan[eps], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(-1.0 / N[Tan[x], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[eps, -2.15e-9], N[((-N[Tan[x], $MachinePrecision]) - N[(t$95$1 / N[(N[Tan[x], $MachinePrecision] * N[Tan[eps], $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[eps, 5.2e-9], N[(eps + N[(eps * N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(t$95$0 + N[(t$95$1 * t$95$2), $MachinePrecision]), $MachinePrecision] / N[(t$95$0 * t$95$2), $MachinePrecision]), $MachinePrecision]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := 1 - \tan x \cdot \tan \varepsilon\\
t_1 := \tan x + \tan \varepsilon\\
t_2 := \frac{-1}{\tan x}\\
\mathbf{if}\;\varepsilon \leq -2.15 \cdot 10^{-9}:\\
\;\;\;\;\left(-\tan x\right) - \frac{t_1}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}\\

\mathbf{elif}\;\varepsilon \leq 5.2 \cdot 10^{-9}:\\
\;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\

\mathbf{else}:\\
\;\;\;\;\frac{t_0 + t_1 \cdot t_2}{t_0 \cdot t_2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if eps < -2.14999999999999981e-9

    1. Initial program 44.9%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum99.5%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv99.5%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
    3. Applied egg-rr99.5%

      \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
    4. Step-by-step derivation
      1. *-commutative99.5%

        \[\leadsto \color{blue}{\frac{1}{1 - \tan x \cdot \tan \varepsilon} \cdot \left(\tan x + \tan \varepsilon\right)} - \tan x \]
      2. distribute-lft-in99.4%

        \[\leadsto \color{blue}{\left(\frac{1}{1 - \tan x \cdot \tan \varepsilon} \cdot \tan x + \frac{1}{1 - \tan x \cdot \tan \varepsilon} \cdot \tan \varepsilon\right)} - \tan x \]
    5. Applied egg-rr99.4%

      \[\leadsto \color{blue}{\left(\frac{-1}{-1 + \tan x \cdot \tan \varepsilon} \cdot \tan x + \frac{-1}{-1 + \tan x \cdot \tan \varepsilon} \cdot \tan \varepsilon\right)} - \tan x \]
    6. Step-by-step derivation
      1. distribute-lft-in99.5%

        \[\leadsto \color{blue}{\frac{-1}{-1 + \tan x \cdot \tan \varepsilon} \cdot \left(\tan x + \tan \varepsilon\right)} - \tan x \]
      2. associate-*l/99.5%

        \[\leadsto \color{blue}{\frac{-1 \cdot \left(\tan x + \tan \varepsilon\right)}{-1 + \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. neg-mul-199.5%

        \[\leadsto \frac{\color{blue}{-\left(\tan x + \tan \varepsilon\right)}}{-1 + \tan x \cdot \tan \varepsilon} - \tan x \]
      4. distribute-neg-in99.5%

        \[\leadsto \frac{\color{blue}{\left(-\tan x\right) + \left(-\tan \varepsilon\right)}}{-1 + \tan x \cdot \tan \varepsilon} - \tan x \]
      5. unsub-neg99.5%

        \[\leadsto \frac{\color{blue}{\left(-\tan x\right) - \tan \varepsilon}}{-1 + \tan x \cdot \tan \varepsilon} - \tan x \]
      6. +-commutative99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\color{blue}{\tan x \cdot \tan \varepsilon + -1}} - \tan x \]
      7. metadata-eval99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\tan x \cdot \tan \varepsilon + \color{blue}{\left(-1\right)}} - \tan x \]
      8. sub-neg99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\color{blue}{\tan x \cdot \tan \varepsilon - 1}} - \tan x \]
      9. fma-neg99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\color{blue}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}} - \tan x \]
      10. metadata-eval99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\mathsf{fma}\left(\tan x, \tan \varepsilon, \color{blue}{-1}\right)} - \tan x \]
    7. Simplified99.5%

      \[\leadsto \color{blue}{\frac{\left(-\tan x\right) - \tan \varepsilon}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}} - \tan x \]

    if -2.14999999999999981e-9 < eps < 5.2000000000000002e-9

    1. Initial program 28.0%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum28.5%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv28.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. fma-neg28.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    3. Applied egg-rr28.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    4. Step-by-step derivation
      1. fma-neg28.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
      2. associate-*r/28.5%

        \[\leadsto \color{blue}{\frac{\left(\tan x + \tan \varepsilon\right) \cdot 1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. *-rgt-identity28.5%

        \[\leadsto \frac{\color{blue}{\tan x + \tan \varepsilon}}{1 - \tan x \cdot \tan \varepsilon} - \tan x \]
    5. Simplified28.5%

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
    6. Taylor expanded in eps around 0 99.5%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    7. Step-by-step derivation
      1. cancel-sign-sub-inv99.5%

        \[\leadsto \varepsilon \cdot \color{blue}{\left(1 + \left(--1\right) \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
      2. metadata-eval99.5%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{1} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
      3. *-lft-identity99.5%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{\frac{{\sin x}^{2}}{{\cos x}^{2}}}\right) \]
    8. Simplified99.5%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 + \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    9. Step-by-step derivation
      1. distribute-rgt-in99.7%

        \[\leadsto \color{blue}{1 \cdot \varepsilon + \frac{{\sin x}^{2}}{{\cos x}^{2}} \cdot \varepsilon} \]
      2. *-un-lft-identity99.7%

        \[\leadsto \color{blue}{\varepsilon} + \frac{{\sin x}^{2}}{{\cos x}^{2}} \cdot \varepsilon \]
      3. unpow299.7%

        \[\leadsto \varepsilon + \frac{\color{blue}{\sin x \cdot \sin x}}{{\cos x}^{2}} \cdot \varepsilon \]
      4. unpow299.7%

        \[\leadsto \varepsilon + \frac{\sin x \cdot \sin x}{\color{blue}{\cos x \cdot \cos x}} \cdot \varepsilon \]
      5. frac-times99.6%

        \[\leadsto \varepsilon + \color{blue}{\left(\frac{\sin x}{\cos x} \cdot \frac{\sin x}{\cos x}\right)} \cdot \varepsilon \]
      6. tan-quot99.7%

        \[\leadsto \varepsilon + \left(\color{blue}{\tan x} \cdot \frac{\sin x}{\cos x}\right) \cdot \varepsilon \]
      7. tan-quot99.7%

        \[\leadsto \varepsilon + \left(\tan x \cdot \color{blue}{\tan x}\right) \cdot \varepsilon \]
      8. pow299.7%

        \[\leadsto \varepsilon + \color{blue}{{\tan x}^{2}} \cdot \varepsilon \]
    10. Applied egg-rr99.7%

      \[\leadsto \color{blue}{\varepsilon + {\tan x}^{2} \cdot \varepsilon} \]

    if 5.2000000000000002e-9 < eps

    1. Initial program 51.7%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum99.3%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv99.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. fma-neg99.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    3. Applied egg-rr99.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    4. Step-by-step derivation
      1. fma-neg99.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
      2. associate-*r/99.3%

        \[\leadsto \color{blue}{\frac{\left(\tan x + \tan \varepsilon\right) \cdot 1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. *-rgt-identity99.3%

        \[\leadsto \frac{\color{blue}{\tan x + \tan \varepsilon}}{1 - \tan x \cdot \tan \varepsilon} - \tan x \]
    5. Simplified99.3%

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
    6. Step-by-step derivation
      1. frac-2neg99.3%

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

        \[\leadsto \frac{-\left(\tan x + \tan \varepsilon\right)}{-\left(1 - \color{blue}{\tan \varepsilon \cdot \tan x}\right)} - \tan x \]
      3. tan-quot99.3%

        \[\leadsto \frac{-\left(\tan x + \tan \varepsilon\right)}{-\left(1 - \color{blue}{\frac{\sin \varepsilon}{\cos \varepsilon}} \cdot \tan x\right)} - \tan x \]
      4. tan-quot99.2%

        \[\leadsto \frac{-\left(\tan x + \tan \varepsilon\right)}{-\left(1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \color{blue}{\frac{\sin x}{\cos x}}\right)} - \tan x \]
      5. tan-quot99.1%

        \[\leadsto \frac{-\left(\tan x + \tan \varepsilon\right)}{-\left(1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}\right)} - \color{blue}{\frac{\sin x}{\cos x}} \]
      6. clear-num99.1%

        \[\leadsto \frac{-\left(\tan x + \tan \varepsilon\right)}{-\left(1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}\right)} - \color{blue}{\frac{1}{\frac{\cos x}{\sin x}}} \]
      7. frac-sub99.1%

        \[\leadsto \color{blue}{\frac{\left(-\left(\tan x + \tan \varepsilon\right)\right) \cdot \frac{\cos x}{\sin x} - \left(-\left(1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}\right)\right) \cdot 1}{\left(-\left(1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}\right)\right) \cdot \frac{\cos x}{\sin x}}} \]
    7. Applied egg-rr99.5%

      \[\leadsto \color{blue}{\frac{\left(-\left(\tan x + \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x} - \left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot 1}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -2.15 \cdot 10^{-9}:\\ \;\;\;\;\left(-\tan x\right) - \frac{\tan x + \tan \varepsilon}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}\\ \mathbf{elif}\;\varepsilon \leq 5.2 \cdot 10^{-9}:\\ \;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\left(1 - \tan x \cdot \tan \varepsilon\right) + \left(\tan x + \tan \varepsilon\right) \cdot \frac{-1}{\tan x}}{\left(1 - \tan x \cdot \tan \varepsilon\right) \cdot \frac{-1}{\tan x}}\\ \end{array} \]

Alternative 2: 99.5% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \tan x \cdot \tan \varepsilon\\ t_1 := \frac{\sin \varepsilon}{\cos \varepsilon}\\ \frac{t_1}{1 - t_1 \cdot \frac{\sin x}{\cos x}} - \frac{t_0}{\frac{t_0 + -1}{\tan x}} \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (* (tan x) (tan eps))) (t_1 (/ (sin eps) (cos eps))))
   (-
    (/ t_1 (- 1.0 (* t_1 (/ (sin x) (cos x)))))
    (/ t_0 (/ (+ t_0 -1.0) (tan x))))))
double code(double x, double eps) {
	double t_0 = tan(x) * tan(eps);
	double t_1 = sin(eps) / cos(eps);
	return (t_1 / (1.0 - (t_1 * (sin(x) / cos(x))))) - (t_0 / ((t_0 + -1.0) / tan(x)));
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: t_0
    real(8) :: t_1
    t_0 = tan(x) * tan(eps)
    t_1 = sin(eps) / cos(eps)
    code = (t_1 / (1.0d0 - (t_1 * (sin(x) / cos(x))))) - (t_0 / ((t_0 + (-1.0d0)) / tan(x)))
end function
public static double code(double x, double eps) {
	double t_0 = Math.tan(x) * Math.tan(eps);
	double t_1 = Math.sin(eps) / Math.cos(eps);
	return (t_1 / (1.0 - (t_1 * (Math.sin(x) / Math.cos(x))))) - (t_0 / ((t_0 + -1.0) / Math.tan(x)));
}
def code(x, eps):
	t_0 = math.tan(x) * math.tan(eps)
	t_1 = math.sin(eps) / math.cos(eps)
	return (t_1 / (1.0 - (t_1 * (math.sin(x) / math.cos(x))))) - (t_0 / ((t_0 + -1.0) / math.tan(x)))
function code(x, eps)
	t_0 = Float64(tan(x) * tan(eps))
	t_1 = Float64(sin(eps) / cos(eps))
	return Float64(Float64(t_1 / Float64(1.0 - Float64(t_1 * Float64(sin(x) / cos(x))))) - Float64(t_0 / Float64(Float64(t_0 + -1.0) / tan(x))))
end
function tmp = code(x, eps)
	t_0 = tan(x) * tan(eps);
	t_1 = sin(eps) / cos(eps);
	tmp = (t_1 / (1.0 - (t_1 * (sin(x) / cos(x))))) - (t_0 / ((t_0 + -1.0) / tan(x)));
end
code[x_, eps_] := Block[{t$95$0 = N[(N[Tan[x], $MachinePrecision] * N[Tan[eps], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[Sin[eps], $MachinePrecision] / N[Cos[eps], $MachinePrecision]), $MachinePrecision]}, N[(N[(t$95$1 / N[(1.0 - N[(t$95$1 * N[(N[Sin[x], $MachinePrecision] / N[Cos[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(t$95$0 / N[(N[(t$95$0 + -1.0), $MachinePrecision] / N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \tan x \cdot \tan \varepsilon\\
t_1 := \frac{\sin \varepsilon}{\cos \varepsilon}\\
\frac{t_1}{1 - t_1 \cdot \frac{\sin x}{\cos x}} - \frac{t_0}{\frac{t_0 + -1}{\tan x}}
\end{array}
\end{array}
Derivation
  1. Initial program 38.5%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Step-by-step derivation
    1. tan-sum65.3%

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
    2. div-inv65.3%

      \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
  3. Applied egg-rr65.3%

    \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
  4. Taylor expanded in x around inf 65.1%

    \[\leadsto \color{blue}{\left(\frac{\sin \varepsilon}{\cos \varepsilon \cdot \left(1 - \frac{\sin x \cdot \sin \varepsilon}{\cos \varepsilon \cdot \cos x}\right)} + \frac{\sin x}{\cos x \cdot \left(1 - \frac{\sin x \cdot \sin \varepsilon}{\cos \varepsilon \cdot \cos x}\right)}\right) - \frac{\sin x}{\cos x}} \]
  5. Step-by-step derivation
    1. associate--l+76.8%

      \[\leadsto \color{blue}{\frac{\sin \varepsilon}{\cos \varepsilon \cdot \left(1 - \frac{\sin x \cdot \sin \varepsilon}{\cos \varepsilon \cdot \cos x}\right)} + \left(\frac{\sin x}{\cos x \cdot \left(1 - \frac{\sin x \cdot \sin \varepsilon}{\cos \varepsilon \cdot \cos x}\right)} - \frac{\sin x}{\cos x}\right)} \]
    2. associate-/r*76.8%

      \[\leadsto \color{blue}{\frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin x \cdot \sin \varepsilon}{\cos \varepsilon \cdot \cos x}}} + \left(\frac{\sin x}{\cos x \cdot \left(1 - \frac{\sin x \cdot \sin \varepsilon}{\cos \varepsilon \cdot \cos x}\right)} - \frac{\sin x}{\cos x}\right) \]
    3. *-commutative76.8%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\color{blue}{\sin \varepsilon \cdot \sin x}}{\cos \varepsilon \cdot \cos x}} + \left(\frac{\sin x}{\cos x \cdot \left(1 - \frac{\sin x \cdot \sin \varepsilon}{\cos \varepsilon \cdot \cos x}\right)} - \frac{\sin x}{\cos x}\right) \]
    4. times-frac76.9%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \color{blue}{\frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}}} + \left(\frac{\sin x}{\cos x \cdot \left(1 - \frac{\sin x \cdot \sin \varepsilon}{\cos \varepsilon \cdot \cos x}\right)} - \frac{\sin x}{\cos x}\right) \]
  6. Simplified76.8%

    \[\leadsto \color{blue}{\frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \left(\frac{\frac{\sin x}{\cos x}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} - \frac{\sin x}{\cos x}\right)} \]
  7. Step-by-step derivation
    1. tan-quot75.4%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \left(\frac{\color{blue}{\tan x}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} - \frac{\sin x}{\cos x}\right) \]
    2. frac-2neg75.4%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \left(\color{blue}{\frac{-\tan x}{-\left(1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}\right)}} - \frac{\sin x}{\cos x}\right) \]
    3. clear-num73.9%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \left(\frac{-\tan x}{-\left(1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}\right)} - \color{blue}{\frac{1}{\frac{\cos x}{\sin x}}}\right) \]
    4. frac-sub73.4%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \color{blue}{\frac{\left(-\tan x\right) \cdot \frac{\cos x}{\sin x} - \left(-\left(1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}\right)\right) \cdot 1}{\left(-\left(1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}\right)\right) \cdot \frac{\cos x}{\sin x}}} \]
  8. Applied egg-rr74.6%

    \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \color{blue}{\frac{\left(-\tan x\right) \cdot \frac{1}{\tan x} - \left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot 1}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}}} \]
  9. Step-by-step derivation
    1. cancel-sign-sub74.6%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\color{blue}{\left(-\tan x\right) \cdot \frac{1}{\tan x} + \left(1 - \tan x \cdot \tan \varepsilon\right) \cdot 1}}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}} \]
    2. distribute-lft-neg-out74.6%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\color{blue}{\left(-\tan x \cdot \frac{1}{\tan x}\right)} + \left(1 - \tan x \cdot \tan \varepsilon\right) \cdot 1}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}} \]
    3. rgt-mult-inverse76.9%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\left(-\color{blue}{1}\right) + \left(1 - \tan x \cdot \tan \varepsilon\right) \cdot 1}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}} \]
    4. metadata-eval76.9%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\color{blue}{-1} + \left(1 - \tan x \cdot \tan \varepsilon\right) \cdot 1}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}} \]
    5. *-rgt-identity76.9%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{-1 + \color{blue}{\left(1 - \tan x \cdot \tan \varepsilon\right)}}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}} \]
    6. associate-+r-99.5%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\color{blue}{\left(-1 + 1\right) - \tan x \cdot \tan \varepsilon}}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}} \]
    7. metadata-eval99.5%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\color{blue}{0} - \tan x \cdot \tan \varepsilon}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}} \]
    8. neg-sub099.5%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\color{blue}{-\tan x \cdot \tan \varepsilon}}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}} \]
    9. distribute-rgt-neg-in99.5%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\color{blue}{\tan x \cdot \left(-\tan \varepsilon\right)}}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}} \]
    10. associate-*r/99.5%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\color{blue}{\frac{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot 1}{\tan x}}} \]
    11. *-rgt-identity99.5%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{\color{blue}{-\left(1 - \tan x \cdot \tan \varepsilon\right)}}{\tan x}} \]
  10. Simplified99.5%

    \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \color{blue}{\frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}}} \]
  11. Final simplification99.5%

    \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} - \frac{\tan x \cdot \tan \varepsilon}{\frac{\tan x \cdot \tan \varepsilon + -1}{\tan x}} \]

Alternative 3: 99.5% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \tan x \cdot \tan \varepsilon\\ \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - t_0} - \frac{t_0}{\frac{t_0 + -1}{\tan x}} \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (* (tan x) (tan eps))))
   (-
    (/ (/ (sin eps) (cos eps)) (- 1.0 t_0))
    (/ t_0 (/ (+ t_0 -1.0) (tan x))))))
double code(double x, double eps) {
	double t_0 = tan(x) * tan(eps);
	return ((sin(eps) / cos(eps)) / (1.0 - t_0)) - (t_0 / ((t_0 + -1.0) / tan(x)));
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: t_0
    t_0 = tan(x) * tan(eps)
    code = ((sin(eps) / cos(eps)) / (1.0d0 - t_0)) - (t_0 / ((t_0 + (-1.0d0)) / tan(x)))
end function
public static double code(double x, double eps) {
	double t_0 = Math.tan(x) * Math.tan(eps);
	return ((Math.sin(eps) / Math.cos(eps)) / (1.0 - t_0)) - (t_0 / ((t_0 + -1.0) / Math.tan(x)));
}
def code(x, eps):
	t_0 = math.tan(x) * math.tan(eps)
	return ((math.sin(eps) / math.cos(eps)) / (1.0 - t_0)) - (t_0 / ((t_0 + -1.0) / math.tan(x)))
function code(x, eps)
	t_0 = Float64(tan(x) * tan(eps))
	return Float64(Float64(Float64(sin(eps) / cos(eps)) / Float64(1.0 - t_0)) - Float64(t_0 / Float64(Float64(t_0 + -1.0) / tan(x))))
end
function tmp = code(x, eps)
	t_0 = tan(x) * tan(eps);
	tmp = ((sin(eps) / cos(eps)) / (1.0 - t_0)) - (t_0 / ((t_0 + -1.0) / tan(x)));
end
code[x_, eps_] := Block[{t$95$0 = N[(N[Tan[x], $MachinePrecision] * N[Tan[eps], $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(N[Sin[eps], $MachinePrecision] / N[Cos[eps], $MachinePrecision]), $MachinePrecision] / N[(1.0 - t$95$0), $MachinePrecision]), $MachinePrecision] - N[(t$95$0 / N[(N[(t$95$0 + -1.0), $MachinePrecision] / N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \tan x \cdot \tan \varepsilon\\
\frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - t_0} - \frac{t_0}{\frac{t_0 + -1}{\tan x}}
\end{array}
\end{array}
Derivation
  1. Initial program 38.5%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Step-by-step derivation
    1. tan-sum65.3%

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
    2. div-inv65.3%

      \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
  3. Applied egg-rr65.3%

    \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
  4. Taylor expanded in x around inf 65.1%

    \[\leadsto \color{blue}{\left(\frac{\sin \varepsilon}{\cos \varepsilon \cdot \left(1 - \frac{\sin x \cdot \sin \varepsilon}{\cos \varepsilon \cdot \cos x}\right)} + \frac{\sin x}{\cos x \cdot \left(1 - \frac{\sin x \cdot \sin \varepsilon}{\cos \varepsilon \cdot \cos x}\right)}\right) - \frac{\sin x}{\cos x}} \]
  5. Step-by-step derivation
    1. associate--l+76.8%

      \[\leadsto \color{blue}{\frac{\sin \varepsilon}{\cos \varepsilon \cdot \left(1 - \frac{\sin x \cdot \sin \varepsilon}{\cos \varepsilon \cdot \cos x}\right)} + \left(\frac{\sin x}{\cos x \cdot \left(1 - \frac{\sin x \cdot \sin \varepsilon}{\cos \varepsilon \cdot \cos x}\right)} - \frac{\sin x}{\cos x}\right)} \]
    2. associate-/r*76.8%

      \[\leadsto \color{blue}{\frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin x \cdot \sin \varepsilon}{\cos \varepsilon \cdot \cos x}}} + \left(\frac{\sin x}{\cos x \cdot \left(1 - \frac{\sin x \cdot \sin \varepsilon}{\cos \varepsilon \cdot \cos x}\right)} - \frac{\sin x}{\cos x}\right) \]
    3. *-commutative76.8%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\color{blue}{\sin \varepsilon \cdot \sin x}}{\cos \varepsilon \cdot \cos x}} + \left(\frac{\sin x}{\cos x \cdot \left(1 - \frac{\sin x \cdot \sin \varepsilon}{\cos \varepsilon \cdot \cos x}\right)} - \frac{\sin x}{\cos x}\right) \]
    4. times-frac76.9%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \color{blue}{\frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}}} + \left(\frac{\sin x}{\cos x \cdot \left(1 - \frac{\sin x \cdot \sin \varepsilon}{\cos \varepsilon \cdot \cos x}\right)} - \frac{\sin x}{\cos x}\right) \]
  6. Simplified76.8%

    \[\leadsto \color{blue}{\frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \left(\frac{\frac{\sin x}{\cos x}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} - \frac{\sin x}{\cos x}\right)} \]
  7. Step-by-step derivation
    1. tan-quot75.4%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \left(\frac{\color{blue}{\tan x}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} - \frac{\sin x}{\cos x}\right) \]
    2. frac-2neg75.4%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \left(\color{blue}{\frac{-\tan x}{-\left(1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}\right)}} - \frac{\sin x}{\cos x}\right) \]
    3. clear-num73.9%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \left(\frac{-\tan x}{-\left(1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}\right)} - \color{blue}{\frac{1}{\frac{\cos x}{\sin x}}}\right) \]
    4. frac-sub73.4%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \color{blue}{\frac{\left(-\tan x\right) \cdot \frac{\cos x}{\sin x} - \left(-\left(1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}\right)\right) \cdot 1}{\left(-\left(1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}\right)\right) \cdot \frac{\cos x}{\sin x}}} \]
  8. Applied egg-rr74.6%

    \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \color{blue}{\frac{\left(-\tan x\right) \cdot \frac{1}{\tan x} - \left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot 1}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}}} \]
  9. Step-by-step derivation
    1. cancel-sign-sub74.6%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\color{blue}{\left(-\tan x\right) \cdot \frac{1}{\tan x} + \left(1 - \tan x \cdot \tan \varepsilon\right) \cdot 1}}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}} \]
    2. distribute-lft-neg-out74.6%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\color{blue}{\left(-\tan x \cdot \frac{1}{\tan x}\right)} + \left(1 - \tan x \cdot \tan \varepsilon\right) \cdot 1}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}} \]
    3. rgt-mult-inverse76.9%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\left(-\color{blue}{1}\right) + \left(1 - \tan x \cdot \tan \varepsilon\right) \cdot 1}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}} \]
    4. metadata-eval76.9%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\color{blue}{-1} + \left(1 - \tan x \cdot \tan \varepsilon\right) \cdot 1}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}} \]
    5. *-rgt-identity76.9%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{-1 + \color{blue}{\left(1 - \tan x \cdot \tan \varepsilon\right)}}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}} \]
    6. associate-+r-99.5%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\color{blue}{\left(-1 + 1\right) - \tan x \cdot \tan \varepsilon}}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}} \]
    7. metadata-eval99.5%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\color{blue}{0} - \tan x \cdot \tan \varepsilon}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}} \]
    8. neg-sub099.5%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\color{blue}{-\tan x \cdot \tan \varepsilon}}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}} \]
    9. distribute-rgt-neg-in99.5%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\color{blue}{\tan x \cdot \left(-\tan \varepsilon\right)}}{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot \frac{1}{\tan x}} \]
    10. associate-*r/99.5%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\color{blue}{\frac{\left(-\left(1 - \tan x \cdot \tan \varepsilon\right)\right) \cdot 1}{\tan x}}} \]
    11. *-rgt-identity99.5%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{\color{blue}{-\left(1 - \tan x \cdot \tan \varepsilon\right)}}{\tan x}} \]
  10. Simplified99.5%

    \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}} + \color{blue}{\frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}}} \]
  11. Step-by-step derivation
    1. tan-quot99.4%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \color{blue}{\tan \varepsilon} \cdot \frac{\sin x}{\cos x}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}} \]
    2. tan-quot99.4%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \tan \varepsilon \cdot \color{blue}{\tan x}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}} \]
    3. *-commutative99.4%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \color{blue}{\tan x \cdot \tan \varepsilon}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}} \]
    4. tan-quot99.4%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \color{blue}{\frac{\sin x}{\cos x}} \cdot \tan \varepsilon} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}} \]
    5. clear-num99.4%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \color{blue}{\frac{1}{\frac{\cos x}{\sin x}}} \cdot \tan \varepsilon} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}} \]
    6. tan-quot99.5%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{1}{\frac{\cos x}{\sin x}} \cdot \color{blue}{\frac{\sin \varepsilon}{\cos \varepsilon}}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}} \]
    7. clear-num99.5%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{1}{\frac{\cos x}{\sin x}} \cdot \color{blue}{\frac{1}{\frac{\cos \varepsilon}{\sin \varepsilon}}}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}} \]
    8. frac-times99.5%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \color{blue}{\frac{1 \cdot 1}{\frac{\cos x}{\sin x} \cdot \frac{\cos \varepsilon}{\sin \varepsilon}}}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}} \]
    9. metadata-eval99.5%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\color{blue}{1}}{\frac{\cos x}{\sin x} \cdot \frac{\cos \varepsilon}{\sin \varepsilon}}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}} \]
    10. clear-num99.5%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{1}{\color{blue}{\frac{1}{\frac{\sin x}{\cos x}}} \cdot \frac{\cos \varepsilon}{\sin \varepsilon}}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}} \]
    11. tan-quot99.5%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{1}{\frac{1}{\color{blue}{\tan x}} \cdot \frac{\cos \varepsilon}{\sin \varepsilon}}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}} \]
    12. clear-num99.5%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{1}{\frac{1}{\tan x} \cdot \color{blue}{\frac{1}{\frac{\sin \varepsilon}{\cos \varepsilon}}}}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}} \]
    13. tan-quot99.4%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{1}{\frac{1}{\tan x} \cdot \frac{1}{\color{blue}{\tan \varepsilon}}}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}} \]
  12. Applied egg-rr99.4%

    \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \color{blue}{\frac{1}{\frac{1}{\tan x} \cdot \frac{1}{\tan \varepsilon}}}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}} \]
  13. Step-by-step derivation
    1. associate-/r*99.4%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \color{blue}{\frac{\frac{1}{\frac{1}{\tan x}}}{\frac{1}{\tan \varepsilon}}}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}} \]
    2. remove-double-div99.4%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \frac{\color{blue}{\tan x}}{\frac{1}{\tan \varepsilon}}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}} \]
    3. associate-/r/99.4%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \color{blue}{\frac{\tan x}{1} \cdot \tan \varepsilon}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}} \]
    4. /-rgt-identity99.4%

      \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \color{blue}{\tan x} \cdot \tan \varepsilon} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}} \]
  14. Simplified99.4%

    \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \color{blue}{\tan x \cdot \tan \varepsilon}} + \frac{\tan x \cdot \left(-\tan \varepsilon\right)}{\frac{-\left(1 - \tan x \cdot \tan \varepsilon\right)}{\tan x}} \]
  15. Final simplification99.4%

    \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{1 - \tan x \cdot \tan \varepsilon} - \frac{\tan x \cdot \tan \varepsilon}{\frac{\tan x \cdot \tan \varepsilon + -1}{\tan x}} \]

Alternative 4: 99.4% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := -\tan x\\ t_1 := \tan x + \tan \varepsilon\\ \mathbf{if}\;\varepsilon \leq -6.1 \cdot 10^{-9}:\\ \;\;\;\;t_0 - \frac{t_1}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}\\ \mathbf{elif}\;\varepsilon \leq 4.5 \cdot 10^{-9}:\\ \;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(t_1, \frac{1}{1 - \frac{\sin x \cdot \tan \varepsilon}{\cos x}}, t_0\right)\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (- (tan x))) (t_1 (+ (tan x) (tan eps))))
   (if (<= eps -6.1e-9)
     (- t_0 (/ t_1 (fma (tan x) (tan eps) -1.0)))
     (if (<= eps 4.5e-9)
       (+ eps (* eps (pow (tan x) 2.0)))
       (fma t_1 (/ 1.0 (- 1.0 (/ (* (sin x) (tan eps)) (cos x)))) t_0)))))
double code(double x, double eps) {
	double t_0 = -tan(x);
	double t_1 = tan(x) + tan(eps);
	double tmp;
	if (eps <= -6.1e-9) {
		tmp = t_0 - (t_1 / fma(tan(x), tan(eps), -1.0));
	} else if (eps <= 4.5e-9) {
		tmp = eps + (eps * pow(tan(x), 2.0));
	} else {
		tmp = fma(t_1, (1.0 / (1.0 - ((sin(x) * tan(eps)) / cos(x)))), t_0);
	}
	return tmp;
}
function code(x, eps)
	t_0 = Float64(-tan(x))
	t_1 = Float64(tan(x) + tan(eps))
	tmp = 0.0
	if (eps <= -6.1e-9)
		tmp = Float64(t_0 - Float64(t_1 / fma(tan(x), tan(eps), -1.0)));
	elseif (eps <= 4.5e-9)
		tmp = Float64(eps + Float64(eps * (tan(x) ^ 2.0)));
	else
		tmp = fma(t_1, Float64(1.0 / Float64(1.0 - Float64(Float64(sin(x) * tan(eps)) / cos(x)))), t_0);
	end
	return tmp
end
code[x_, eps_] := Block[{t$95$0 = (-N[Tan[x], $MachinePrecision])}, Block[{t$95$1 = N[(N[Tan[x], $MachinePrecision] + N[Tan[eps], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[eps, -6.1e-9], N[(t$95$0 - N[(t$95$1 / N[(N[Tan[x], $MachinePrecision] * N[Tan[eps], $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[eps, 4.5e-9], N[(eps + N[(eps * N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(t$95$1 * N[(1.0 / N[(1.0 - N[(N[(N[Sin[x], $MachinePrecision] * N[Tan[eps], $MachinePrecision]), $MachinePrecision] / N[Cos[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$0), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := -\tan x\\
t_1 := \tan x + \tan \varepsilon\\
\mathbf{if}\;\varepsilon \leq -6.1 \cdot 10^{-9}:\\
\;\;\;\;t_0 - \frac{t_1}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}\\

\mathbf{elif}\;\varepsilon \leq 4.5 \cdot 10^{-9}:\\
\;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(t_1, \frac{1}{1 - \frac{\sin x \cdot \tan \varepsilon}{\cos x}}, t_0\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if eps < -6.1e-9

    1. Initial program 44.9%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum99.5%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv99.5%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
    3. Applied egg-rr99.5%

      \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
    4. Step-by-step derivation
      1. *-commutative99.5%

        \[\leadsto \color{blue}{\frac{1}{1 - \tan x \cdot \tan \varepsilon} \cdot \left(\tan x + \tan \varepsilon\right)} - \tan x \]
      2. distribute-lft-in99.4%

        \[\leadsto \color{blue}{\left(\frac{1}{1 - \tan x \cdot \tan \varepsilon} \cdot \tan x + \frac{1}{1 - \tan x \cdot \tan \varepsilon} \cdot \tan \varepsilon\right)} - \tan x \]
    5. Applied egg-rr99.4%

      \[\leadsto \color{blue}{\left(\frac{-1}{-1 + \tan x \cdot \tan \varepsilon} \cdot \tan x + \frac{-1}{-1 + \tan x \cdot \tan \varepsilon} \cdot \tan \varepsilon\right)} - \tan x \]
    6. Step-by-step derivation
      1. distribute-lft-in99.5%

        \[\leadsto \color{blue}{\frac{-1}{-1 + \tan x \cdot \tan \varepsilon} \cdot \left(\tan x + \tan \varepsilon\right)} - \tan x \]
      2. associate-*l/99.5%

        \[\leadsto \color{blue}{\frac{-1 \cdot \left(\tan x + \tan \varepsilon\right)}{-1 + \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. neg-mul-199.5%

        \[\leadsto \frac{\color{blue}{-\left(\tan x + \tan \varepsilon\right)}}{-1 + \tan x \cdot \tan \varepsilon} - \tan x \]
      4. distribute-neg-in99.5%

        \[\leadsto \frac{\color{blue}{\left(-\tan x\right) + \left(-\tan \varepsilon\right)}}{-1 + \tan x \cdot \tan \varepsilon} - \tan x \]
      5. unsub-neg99.5%

        \[\leadsto \frac{\color{blue}{\left(-\tan x\right) - \tan \varepsilon}}{-1 + \tan x \cdot \tan \varepsilon} - \tan x \]
      6. +-commutative99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\color{blue}{\tan x \cdot \tan \varepsilon + -1}} - \tan x \]
      7. metadata-eval99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\tan x \cdot \tan \varepsilon + \color{blue}{\left(-1\right)}} - \tan x \]
      8. sub-neg99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\color{blue}{\tan x \cdot \tan \varepsilon - 1}} - \tan x \]
      9. fma-neg99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\color{blue}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}} - \tan x \]
      10. metadata-eval99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\mathsf{fma}\left(\tan x, \tan \varepsilon, \color{blue}{-1}\right)} - \tan x \]
    7. Simplified99.5%

      \[\leadsto \color{blue}{\frac{\left(-\tan x\right) - \tan \varepsilon}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}} - \tan x \]

    if -6.1e-9 < eps < 4.49999999999999976e-9

    1. Initial program 28.0%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum28.5%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv28.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. fma-neg28.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    3. Applied egg-rr28.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    4. Step-by-step derivation
      1. fma-neg28.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
      2. associate-*r/28.5%

        \[\leadsto \color{blue}{\frac{\left(\tan x + \tan \varepsilon\right) \cdot 1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. *-rgt-identity28.5%

        \[\leadsto \frac{\color{blue}{\tan x + \tan \varepsilon}}{1 - \tan x \cdot \tan \varepsilon} - \tan x \]
    5. Simplified28.5%

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
    6. Taylor expanded in eps around 0 99.5%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    7. Step-by-step derivation
      1. cancel-sign-sub-inv99.5%

        \[\leadsto \varepsilon \cdot \color{blue}{\left(1 + \left(--1\right) \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
      2. metadata-eval99.5%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{1} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
      3. *-lft-identity99.5%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{\frac{{\sin x}^{2}}{{\cos x}^{2}}}\right) \]
    8. Simplified99.5%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 + \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    9. Step-by-step derivation
      1. distribute-rgt-in99.7%

        \[\leadsto \color{blue}{1 \cdot \varepsilon + \frac{{\sin x}^{2}}{{\cos x}^{2}} \cdot \varepsilon} \]
      2. *-un-lft-identity99.7%

        \[\leadsto \color{blue}{\varepsilon} + \frac{{\sin x}^{2}}{{\cos x}^{2}} \cdot \varepsilon \]
      3. unpow299.7%

        \[\leadsto \varepsilon + \frac{\color{blue}{\sin x \cdot \sin x}}{{\cos x}^{2}} \cdot \varepsilon \]
      4. unpow299.7%

        \[\leadsto \varepsilon + \frac{\sin x \cdot \sin x}{\color{blue}{\cos x \cdot \cos x}} \cdot \varepsilon \]
      5. frac-times99.6%

        \[\leadsto \varepsilon + \color{blue}{\left(\frac{\sin x}{\cos x} \cdot \frac{\sin x}{\cos x}\right)} \cdot \varepsilon \]
      6. tan-quot99.7%

        \[\leadsto \varepsilon + \left(\color{blue}{\tan x} \cdot \frac{\sin x}{\cos x}\right) \cdot \varepsilon \]
      7. tan-quot99.7%

        \[\leadsto \varepsilon + \left(\tan x \cdot \color{blue}{\tan x}\right) \cdot \varepsilon \]
      8. pow299.7%

        \[\leadsto \varepsilon + \color{blue}{{\tan x}^{2}} \cdot \varepsilon \]
    10. Applied egg-rr99.7%

      \[\leadsto \color{blue}{\varepsilon + {\tan x}^{2} \cdot \varepsilon} \]

    if 4.49999999999999976e-9 < eps

    1. Initial program 51.7%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum99.3%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv99.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. fma-neg99.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    3. Applied egg-rr99.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    4. Step-by-step derivation
      1. *-commutative99.4%

        \[\leadsto \mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \color{blue}{\tan \varepsilon \cdot \tan x}}, -\tan x\right) \]
      2. tan-quot99.3%

        \[\leadsto \mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan \varepsilon \cdot \color{blue}{\frac{\sin x}{\cos x}}}, -\tan x\right) \]
      3. associate-*r/99.4%

        \[\leadsto \mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \color{blue}{\frac{\tan \varepsilon \cdot \sin x}{\cos x}}}, -\tan x\right) \]
    5. Applied egg-rr99.4%

      \[\leadsto \mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \color{blue}{\frac{\tan \varepsilon \cdot \sin x}{\cos x}}}, -\tan x\right) \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -6.1 \cdot 10^{-9}:\\ \;\;\;\;\left(-\tan x\right) - \frac{\tan x + \tan \varepsilon}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}\\ \mathbf{elif}\;\varepsilon \leq 4.5 \cdot 10^{-9}:\\ \;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \frac{\sin x \cdot \tan \varepsilon}{\cos x}}, -\tan x\right)\\ \end{array} \]

Alternative 5: 99.4% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := -\tan x\\ t_1 := \tan x + \tan \varepsilon\\ \mathbf{if}\;\varepsilon \leq -1.9 \cdot 10^{-9}:\\ \;\;\;\;t_0 - \frac{t_1}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}\\ \mathbf{elif}\;\varepsilon \leq 3.8 \cdot 10^{-9}:\\ \;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(t_1, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, t_0\right)\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (- (tan x))) (t_1 (+ (tan x) (tan eps))))
   (if (<= eps -1.9e-9)
     (- t_0 (/ t_1 (fma (tan x) (tan eps) -1.0)))
     (if (<= eps 3.8e-9)
       (+ eps (* eps (pow (tan x) 2.0)))
       (fma t_1 (/ 1.0 (- 1.0 (* (tan x) (tan eps)))) t_0)))))
double code(double x, double eps) {
	double t_0 = -tan(x);
	double t_1 = tan(x) + tan(eps);
	double tmp;
	if (eps <= -1.9e-9) {
		tmp = t_0 - (t_1 / fma(tan(x), tan(eps), -1.0));
	} else if (eps <= 3.8e-9) {
		tmp = eps + (eps * pow(tan(x), 2.0));
	} else {
		tmp = fma(t_1, (1.0 / (1.0 - (tan(x) * tan(eps)))), t_0);
	}
	return tmp;
}
function code(x, eps)
	t_0 = Float64(-tan(x))
	t_1 = Float64(tan(x) + tan(eps))
	tmp = 0.0
	if (eps <= -1.9e-9)
		tmp = Float64(t_0 - Float64(t_1 / fma(tan(x), tan(eps), -1.0)));
	elseif (eps <= 3.8e-9)
		tmp = Float64(eps + Float64(eps * (tan(x) ^ 2.0)));
	else
		tmp = fma(t_1, Float64(1.0 / Float64(1.0 - Float64(tan(x) * tan(eps)))), t_0);
	end
	return tmp
end
code[x_, eps_] := Block[{t$95$0 = (-N[Tan[x], $MachinePrecision])}, Block[{t$95$1 = N[(N[Tan[x], $MachinePrecision] + N[Tan[eps], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[eps, -1.9e-9], N[(t$95$0 - N[(t$95$1 / N[(N[Tan[x], $MachinePrecision] * N[Tan[eps], $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[eps, 3.8e-9], N[(eps + N[(eps * N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(t$95$1 * N[(1.0 / N[(1.0 - N[(N[Tan[x], $MachinePrecision] * N[Tan[eps], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$0), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := -\tan x\\
t_1 := \tan x + \tan \varepsilon\\
\mathbf{if}\;\varepsilon \leq -1.9 \cdot 10^{-9}:\\
\;\;\;\;t_0 - \frac{t_1}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}\\

\mathbf{elif}\;\varepsilon \leq 3.8 \cdot 10^{-9}:\\
\;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(t_1, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, t_0\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if eps < -1.90000000000000006e-9

    1. Initial program 44.9%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum99.5%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv99.5%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
    3. Applied egg-rr99.5%

      \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
    4. Step-by-step derivation
      1. *-commutative99.5%

        \[\leadsto \color{blue}{\frac{1}{1 - \tan x \cdot \tan \varepsilon} \cdot \left(\tan x + \tan \varepsilon\right)} - \tan x \]
      2. distribute-lft-in99.4%

        \[\leadsto \color{blue}{\left(\frac{1}{1 - \tan x \cdot \tan \varepsilon} \cdot \tan x + \frac{1}{1 - \tan x \cdot \tan \varepsilon} \cdot \tan \varepsilon\right)} - \tan x \]
    5. Applied egg-rr99.4%

      \[\leadsto \color{blue}{\left(\frac{-1}{-1 + \tan x \cdot \tan \varepsilon} \cdot \tan x + \frac{-1}{-1 + \tan x \cdot \tan \varepsilon} \cdot \tan \varepsilon\right)} - \tan x \]
    6. Step-by-step derivation
      1. distribute-lft-in99.5%

        \[\leadsto \color{blue}{\frac{-1}{-1 + \tan x \cdot \tan \varepsilon} \cdot \left(\tan x + \tan \varepsilon\right)} - \tan x \]
      2. associate-*l/99.5%

        \[\leadsto \color{blue}{\frac{-1 \cdot \left(\tan x + \tan \varepsilon\right)}{-1 + \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. neg-mul-199.5%

        \[\leadsto \frac{\color{blue}{-\left(\tan x + \tan \varepsilon\right)}}{-1 + \tan x \cdot \tan \varepsilon} - \tan x \]
      4. distribute-neg-in99.5%

        \[\leadsto \frac{\color{blue}{\left(-\tan x\right) + \left(-\tan \varepsilon\right)}}{-1 + \tan x \cdot \tan \varepsilon} - \tan x \]
      5. unsub-neg99.5%

        \[\leadsto \frac{\color{blue}{\left(-\tan x\right) - \tan \varepsilon}}{-1 + \tan x \cdot \tan \varepsilon} - \tan x \]
      6. +-commutative99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\color{blue}{\tan x \cdot \tan \varepsilon + -1}} - \tan x \]
      7. metadata-eval99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\tan x \cdot \tan \varepsilon + \color{blue}{\left(-1\right)}} - \tan x \]
      8. sub-neg99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\color{blue}{\tan x \cdot \tan \varepsilon - 1}} - \tan x \]
      9. fma-neg99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\color{blue}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}} - \tan x \]
      10. metadata-eval99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\mathsf{fma}\left(\tan x, \tan \varepsilon, \color{blue}{-1}\right)} - \tan x \]
    7. Simplified99.5%

      \[\leadsto \color{blue}{\frac{\left(-\tan x\right) - \tan \varepsilon}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}} - \tan x \]

    if -1.90000000000000006e-9 < eps < 3.80000000000000011e-9

    1. Initial program 28.0%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum28.5%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv28.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. fma-neg28.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    3. Applied egg-rr28.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    4. Step-by-step derivation
      1. fma-neg28.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
      2. associate-*r/28.5%

        \[\leadsto \color{blue}{\frac{\left(\tan x + \tan \varepsilon\right) \cdot 1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. *-rgt-identity28.5%

        \[\leadsto \frac{\color{blue}{\tan x + \tan \varepsilon}}{1 - \tan x \cdot \tan \varepsilon} - \tan x \]
    5. Simplified28.5%

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
    6. Taylor expanded in eps around 0 99.5%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    7. Step-by-step derivation
      1. cancel-sign-sub-inv99.5%

        \[\leadsto \varepsilon \cdot \color{blue}{\left(1 + \left(--1\right) \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
      2. metadata-eval99.5%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{1} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
      3. *-lft-identity99.5%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{\frac{{\sin x}^{2}}{{\cos x}^{2}}}\right) \]
    8. Simplified99.5%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 + \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    9. Step-by-step derivation
      1. distribute-rgt-in99.7%

        \[\leadsto \color{blue}{1 \cdot \varepsilon + \frac{{\sin x}^{2}}{{\cos x}^{2}} \cdot \varepsilon} \]
      2. *-un-lft-identity99.7%

        \[\leadsto \color{blue}{\varepsilon} + \frac{{\sin x}^{2}}{{\cos x}^{2}} \cdot \varepsilon \]
      3. unpow299.7%

        \[\leadsto \varepsilon + \frac{\color{blue}{\sin x \cdot \sin x}}{{\cos x}^{2}} \cdot \varepsilon \]
      4. unpow299.7%

        \[\leadsto \varepsilon + \frac{\sin x \cdot \sin x}{\color{blue}{\cos x \cdot \cos x}} \cdot \varepsilon \]
      5. frac-times99.6%

        \[\leadsto \varepsilon + \color{blue}{\left(\frac{\sin x}{\cos x} \cdot \frac{\sin x}{\cos x}\right)} \cdot \varepsilon \]
      6. tan-quot99.7%

        \[\leadsto \varepsilon + \left(\color{blue}{\tan x} \cdot \frac{\sin x}{\cos x}\right) \cdot \varepsilon \]
      7. tan-quot99.7%

        \[\leadsto \varepsilon + \left(\tan x \cdot \color{blue}{\tan x}\right) \cdot \varepsilon \]
      8. pow299.7%

        \[\leadsto \varepsilon + \color{blue}{{\tan x}^{2}} \cdot \varepsilon \]
    10. Applied egg-rr99.7%

      \[\leadsto \color{blue}{\varepsilon + {\tan x}^{2} \cdot \varepsilon} \]

    if 3.80000000000000011e-9 < eps

    1. Initial program 51.7%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum99.3%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv99.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. fma-neg99.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    3. Applied egg-rr99.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -1.9 \cdot 10^{-9}:\\ \;\;\;\;\left(-\tan x\right) - \frac{\tan x + \tan \varepsilon}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}\\ \mathbf{elif}\;\varepsilon \leq 3.8 \cdot 10^{-9}:\\ \;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)\\ \end{array} \]

Alternative 6: 99.4% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \tan x + \tan \varepsilon\\ \mathbf{if}\;\varepsilon \leq -3.2 \cdot 10^{-9}:\\ \;\;\;\;\left(-\tan x\right) - \frac{t_0}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}\\ \mathbf{elif}\;\varepsilon \leq 4.5 \cdot 10^{-9}:\\ \;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\ \mathbf{else}:\\ \;\;\;\;t_0 \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (+ (tan x) (tan eps))))
   (if (<= eps -3.2e-9)
     (- (- (tan x)) (/ t_0 (fma (tan x) (tan eps) -1.0)))
     (if (<= eps 4.5e-9)
       (+ eps (* eps (pow (tan x) 2.0)))
       (- (* t_0 (/ 1.0 (- 1.0 (* (tan x) (tan eps))))) (tan x))))))
double code(double x, double eps) {
	double t_0 = tan(x) + tan(eps);
	double tmp;
	if (eps <= -3.2e-9) {
		tmp = -tan(x) - (t_0 / fma(tan(x), tan(eps), -1.0));
	} else if (eps <= 4.5e-9) {
		tmp = eps + (eps * pow(tan(x), 2.0));
	} else {
		tmp = (t_0 * (1.0 / (1.0 - (tan(x) * tan(eps))))) - tan(x);
	}
	return tmp;
}
function code(x, eps)
	t_0 = Float64(tan(x) + tan(eps))
	tmp = 0.0
	if (eps <= -3.2e-9)
		tmp = Float64(Float64(-tan(x)) - Float64(t_0 / fma(tan(x), tan(eps), -1.0)));
	elseif (eps <= 4.5e-9)
		tmp = Float64(eps + Float64(eps * (tan(x) ^ 2.0)));
	else
		tmp = Float64(Float64(t_0 * Float64(1.0 / Float64(1.0 - Float64(tan(x) * tan(eps))))) - tan(x));
	end
	return tmp
end
code[x_, eps_] := Block[{t$95$0 = N[(N[Tan[x], $MachinePrecision] + N[Tan[eps], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[eps, -3.2e-9], N[((-N[Tan[x], $MachinePrecision]) - N[(t$95$0 / N[(N[Tan[x], $MachinePrecision] * N[Tan[eps], $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[eps, 4.5e-9], N[(eps + N[(eps * N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(t$95$0 * N[(1.0 / N[(1.0 - N[(N[Tan[x], $MachinePrecision] * N[Tan[eps], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Tan[x], $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \tan x + \tan \varepsilon\\
\mathbf{if}\;\varepsilon \leq -3.2 \cdot 10^{-9}:\\
\;\;\;\;\left(-\tan x\right) - \frac{t_0}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}\\

\mathbf{elif}\;\varepsilon \leq 4.5 \cdot 10^{-9}:\\
\;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\

\mathbf{else}:\\
\;\;\;\;t_0 \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if eps < -3.20000000000000012e-9

    1. Initial program 44.9%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum99.5%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv99.5%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
    3. Applied egg-rr99.5%

      \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
    4. Step-by-step derivation
      1. *-commutative99.5%

        \[\leadsto \color{blue}{\frac{1}{1 - \tan x \cdot \tan \varepsilon} \cdot \left(\tan x + \tan \varepsilon\right)} - \tan x \]
      2. distribute-lft-in99.4%

        \[\leadsto \color{blue}{\left(\frac{1}{1 - \tan x \cdot \tan \varepsilon} \cdot \tan x + \frac{1}{1 - \tan x \cdot \tan \varepsilon} \cdot \tan \varepsilon\right)} - \tan x \]
    5. Applied egg-rr99.4%

      \[\leadsto \color{blue}{\left(\frac{-1}{-1 + \tan x \cdot \tan \varepsilon} \cdot \tan x + \frac{-1}{-1 + \tan x \cdot \tan \varepsilon} \cdot \tan \varepsilon\right)} - \tan x \]
    6. Step-by-step derivation
      1. distribute-lft-in99.5%

        \[\leadsto \color{blue}{\frac{-1}{-1 + \tan x \cdot \tan \varepsilon} \cdot \left(\tan x + \tan \varepsilon\right)} - \tan x \]
      2. associate-*l/99.5%

        \[\leadsto \color{blue}{\frac{-1 \cdot \left(\tan x + \tan \varepsilon\right)}{-1 + \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. neg-mul-199.5%

        \[\leadsto \frac{\color{blue}{-\left(\tan x + \tan \varepsilon\right)}}{-1 + \tan x \cdot \tan \varepsilon} - \tan x \]
      4. distribute-neg-in99.5%

        \[\leadsto \frac{\color{blue}{\left(-\tan x\right) + \left(-\tan \varepsilon\right)}}{-1 + \tan x \cdot \tan \varepsilon} - \tan x \]
      5. unsub-neg99.5%

        \[\leadsto \frac{\color{blue}{\left(-\tan x\right) - \tan \varepsilon}}{-1 + \tan x \cdot \tan \varepsilon} - \tan x \]
      6. +-commutative99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\color{blue}{\tan x \cdot \tan \varepsilon + -1}} - \tan x \]
      7. metadata-eval99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\tan x \cdot \tan \varepsilon + \color{blue}{\left(-1\right)}} - \tan x \]
      8. sub-neg99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\color{blue}{\tan x \cdot \tan \varepsilon - 1}} - \tan x \]
      9. fma-neg99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\color{blue}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}} - \tan x \]
      10. metadata-eval99.5%

        \[\leadsto \frac{\left(-\tan x\right) - \tan \varepsilon}{\mathsf{fma}\left(\tan x, \tan \varepsilon, \color{blue}{-1}\right)} - \tan x \]
    7. Simplified99.5%

      \[\leadsto \color{blue}{\frac{\left(-\tan x\right) - \tan \varepsilon}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}} - \tan x \]

    if -3.20000000000000012e-9 < eps < 4.49999999999999976e-9

    1. Initial program 28.0%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum28.5%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv28.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. fma-neg28.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    3. Applied egg-rr28.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    4. Step-by-step derivation
      1. fma-neg28.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
      2. associate-*r/28.5%

        \[\leadsto \color{blue}{\frac{\left(\tan x + \tan \varepsilon\right) \cdot 1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. *-rgt-identity28.5%

        \[\leadsto \frac{\color{blue}{\tan x + \tan \varepsilon}}{1 - \tan x \cdot \tan \varepsilon} - \tan x \]
    5. Simplified28.5%

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
    6. Taylor expanded in eps around 0 99.5%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    7. Step-by-step derivation
      1. cancel-sign-sub-inv99.5%

        \[\leadsto \varepsilon \cdot \color{blue}{\left(1 + \left(--1\right) \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
      2. metadata-eval99.5%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{1} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
      3. *-lft-identity99.5%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{\frac{{\sin x}^{2}}{{\cos x}^{2}}}\right) \]
    8. Simplified99.5%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 + \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    9. Step-by-step derivation
      1. distribute-rgt-in99.7%

        \[\leadsto \color{blue}{1 \cdot \varepsilon + \frac{{\sin x}^{2}}{{\cos x}^{2}} \cdot \varepsilon} \]
      2. *-un-lft-identity99.7%

        \[\leadsto \color{blue}{\varepsilon} + \frac{{\sin x}^{2}}{{\cos x}^{2}} \cdot \varepsilon \]
      3. unpow299.7%

        \[\leadsto \varepsilon + \frac{\color{blue}{\sin x \cdot \sin x}}{{\cos x}^{2}} \cdot \varepsilon \]
      4. unpow299.7%

        \[\leadsto \varepsilon + \frac{\sin x \cdot \sin x}{\color{blue}{\cos x \cdot \cos x}} \cdot \varepsilon \]
      5. frac-times99.6%

        \[\leadsto \varepsilon + \color{blue}{\left(\frac{\sin x}{\cos x} \cdot \frac{\sin x}{\cos x}\right)} \cdot \varepsilon \]
      6. tan-quot99.7%

        \[\leadsto \varepsilon + \left(\color{blue}{\tan x} \cdot \frac{\sin x}{\cos x}\right) \cdot \varepsilon \]
      7. tan-quot99.7%

        \[\leadsto \varepsilon + \left(\tan x \cdot \color{blue}{\tan x}\right) \cdot \varepsilon \]
      8. pow299.7%

        \[\leadsto \varepsilon + \color{blue}{{\tan x}^{2}} \cdot \varepsilon \]
    10. Applied egg-rr99.7%

      \[\leadsto \color{blue}{\varepsilon + {\tan x}^{2} \cdot \varepsilon} \]

    if 4.49999999999999976e-9 < eps

    1. Initial program 51.7%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum99.3%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv99.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
    3. Applied egg-rr99.4%

      \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -3.2 \cdot 10^{-9}:\\ \;\;\;\;\left(-\tan x\right) - \frac{\tan x + \tan \varepsilon}{\mathsf{fma}\left(\tan x, \tan \varepsilon, -1\right)}\\ \mathbf{elif}\;\varepsilon \leq 4.5 \cdot 10^{-9}:\\ \;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\ \mathbf{else}:\\ \;\;\;\;\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x\\ \end{array} \]

Alternative 7: 99.4% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\varepsilon \leq -3.45 \cdot 10^{-9} \lor \neg \left(\varepsilon \leq 3.2 \cdot 10^{-9}\right):\\ \;\;\;\;\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x\\ \mathbf{else}:\\ \;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (or (<= eps -3.45e-9) (not (<= eps 3.2e-9)))
   (- (* (+ (tan x) (tan eps)) (/ 1.0 (- 1.0 (* (tan x) (tan eps))))) (tan x))
   (+ eps (* eps (pow (tan x) 2.0)))))
double code(double x, double eps) {
	double tmp;
	if ((eps <= -3.45e-9) || !(eps <= 3.2e-9)) {
		tmp = ((tan(x) + tan(eps)) * (1.0 / (1.0 - (tan(x) * tan(eps))))) - tan(x);
	} else {
		tmp = eps + (eps * pow(tan(x), 2.0));
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if ((eps <= (-3.45d-9)) .or. (.not. (eps <= 3.2d-9))) then
        tmp = ((tan(x) + tan(eps)) * (1.0d0 / (1.0d0 - (tan(x) * tan(eps))))) - tan(x)
    else
        tmp = eps + (eps * (tan(x) ** 2.0d0))
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if ((eps <= -3.45e-9) || !(eps <= 3.2e-9)) {
		tmp = ((Math.tan(x) + Math.tan(eps)) * (1.0 / (1.0 - (Math.tan(x) * Math.tan(eps))))) - Math.tan(x);
	} else {
		tmp = eps + (eps * Math.pow(Math.tan(x), 2.0));
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if (eps <= -3.45e-9) or not (eps <= 3.2e-9):
		tmp = ((math.tan(x) + math.tan(eps)) * (1.0 / (1.0 - (math.tan(x) * math.tan(eps))))) - math.tan(x)
	else:
		tmp = eps + (eps * math.pow(math.tan(x), 2.0))
	return tmp
function code(x, eps)
	tmp = 0.0
	if ((eps <= -3.45e-9) || !(eps <= 3.2e-9))
		tmp = Float64(Float64(Float64(tan(x) + tan(eps)) * Float64(1.0 / Float64(1.0 - Float64(tan(x) * tan(eps))))) - tan(x));
	else
		tmp = Float64(eps + Float64(eps * (tan(x) ^ 2.0)));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if ((eps <= -3.45e-9) || ~((eps <= 3.2e-9)))
		tmp = ((tan(x) + tan(eps)) * (1.0 / (1.0 - (tan(x) * tan(eps))))) - tan(x);
	else
		tmp = eps + (eps * (tan(x) ^ 2.0));
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[Or[LessEqual[eps, -3.45e-9], N[Not[LessEqual[eps, 3.2e-9]], $MachinePrecision]], N[(N[(N[(N[Tan[x], $MachinePrecision] + N[Tan[eps], $MachinePrecision]), $MachinePrecision] * N[(1.0 / N[(1.0 - N[(N[Tan[x], $MachinePrecision] * N[Tan[eps], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Tan[x], $MachinePrecision]), $MachinePrecision], N[(eps + N[(eps * N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\varepsilon \leq -3.45 \cdot 10^{-9} \lor \neg \left(\varepsilon \leq 3.2 \cdot 10^{-9}\right):\\
\;\;\;\;\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x\\

\mathbf{else}:\\
\;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if eps < -3.44999999999999987e-9 or 3.20000000000000012e-9 < eps

    1. Initial program 48.3%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum99.4%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv99.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
    3. Applied egg-rr99.4%

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

    if -3.44999999999999987e-9 < eps < 3.20000000000000012e-9

    1. Initial program 28.0%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum28.5%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv28.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. fma-neg28.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    3. Applied egg-rr28.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    4. Step-by-step derivation
      1. fma-neg28.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
      2. associate-*r/28.5%

        \[\leadsto \color{blue}{\frac{\left(\tan x + \tan \varepsilon\right) \cdot 1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. *-rgt-identity28.5%

        \[\leadsto \frac{\color{blue}{\tan x + \tan \varepsilon}}{1 - \tan x \cdot \tan \varepsilon} - \tan x \]
    5. Simplified28.5%

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
    6. Taylor expanded in eps around 0 99.5%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    7. Step-by-step derivation
      1. cancel-sign-sub-inv99.5%

        \[\leadsto \varepsilon \cdot \color{blue}{\left(1 + \left(--1\right) \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
      2. metadata-eval99.5%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{1} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
      3. *-lft-identity99.5%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{\frac{{\sin x}^{2}}{{\cos x}^{2}}}\right) \]
    8. Simplified99.5%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 + \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    9. Step-by-step derivation
      1. distribute-rgt-in99.7%

        \[\leadsto \color{blue}{1 \cdot \varepsilon + \frac{{\sin x}^{2}}{{\cos x}^{2}} \cdot \varepsilon} \]
      2. *-un-lft-identity99.7%

        \[\leadsto \color{blue}{\varepsilon} + \frac{{\sin x}^{2}}{{\cos x}^{2}} \cdot \varepsilon \]
      3. unpow299.7%

        \[\leadsto \varepsilon + \frac{\color{blue}{\sin x \cdot \sin x}}{{\cos x}^{2}} \cdot \varepsilon \]
      4. unpow299.7%

        \[\leadsto \varepsilon + \frac{\sin x \cdot \sin x}{\color{blue}{\cos x \cdot \cos x}} \cdot \varepsilon \]
      5. frac-times99.6%

        \[\leadsto \varepsilon + \color{blue}{\left(\frac{\sin x}{\cos x} \cdot \frac{\sin x}{\cos x}\right)} \cdot \varepsilon \]
      6. tan-quot99.7%

        \[\leadsto \varepsilon + \left(\color{blue}{\tan x} \cdot \frac{\sin x}{\cos x}\right) \cdot \varepsilon \]
      7. tan-quot99.7%

        \[\leadsto \varepsilon + \left(\tan x \cdot \color{blue}{\tan x}\right) \cdot \varepsilon \]
      8. pow299.7%

        \[\leadsto \varepsilon + \color{blue}{{\tan x}^{2}} \cdot \varepsilon \]
    10. Applied egg-rr99.7%

      \[\leadsto \color{blue}{\varepsilon + {\tan x}^{2} \cdot \varepsilon} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -3.45 \cdot 10^{-9} \lor \neg \left(\varepsilon \leq 3.2 \cdot 10^{-9}\right):\\ \;\;\;\;\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x\\ \mathbf{else}:\\ \;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\ \end{array} \]

Alternative 8: 99.4% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \tan x + \tan \varepsilon\\ \mathbf{if}\;\varepsilon \leq -3.4 \cdot 10^{-9}:\\ \;\;\;\;\frac{t_0}{1 - \frac{\tan x}{\frac{1}{\tan \varepsilon}}} - \tan x\\ \mathbf{elif}\;\varepsilon \leq 5.2 \cdot 10^{-9}:\\ \;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\ \mathbf{else}:\\ \;\;\;\;t_0 \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (+ (tan x) (tan eps))))
   (if (<= eps -3.4e-9)
     (- (/ t_0 (- 1.0 (/ (tan x) (/ 1.0 (tan eps))))) (tan x))
     (if (<= eps 5.2e-9)
       (+ eps (* eps (pow (tan x) 2.0)))
       (- (* t_0 (/ 1.0 (- 1.0 (* (tan x) (tan eps))))) (tan x))))))
double code(double x, double eps) {
	double t_0 = tan(x) + tan(eps);
	double tmp;
	if (eps <= -3.4e-9) {
		tmp = (t_0 / (1.0 - (tan(x) / (1.0 / tan(eps))))) - tan(x);
	} else if (eps <= 5.2e-9) {
		tmp = eps + (eps * pow(tan(x), 2.0));
	} else {
		tmp = (t_0 * (1.0 / (1.0 - (tan(x) * tan(eps))))) - tan(x);
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: t_0
    real(8) :: tmp
    t_0 = tan(x) + tan(eps)
    if (eps <= (-3.4d-9)) then
        tmp = (t_0 / (1.0d0 - (tan(x) / (1.0d0 / tan(eps))))) - tan(x)
    else if (eps <= 5.2d-9) then
        tmp = eps + (eps * (tan(x) ** 2.0d0))
    else
        tmp = (t_0 * (1.0d0 / (1.0d0 - (tan(x) * tan(eps))))) - tan(x)
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double t_0 = Math.tan(x) + Math.tan(eps);
	double tmp;
	if (eps <= -3.4e-9) {
		tmp = (t_0 / (1.0 - (Math.tan(x) / (1.0 / Math.tan(eps))))) - Math.tan(x);
	} else if (eps <= 5.2e-9) {
		tmp = eps + (eps * Math.pow(Math.tan(x), 2.0));
	} else {
		tmp = (t_0 * (1.0 / (1.0 - (Math.tan(x) * Math.tan(eps))))) - Math.tan(x);
	}
	return tmp;
}
def code(x, eps):
	t_0 = math.tan(x) + math.tan(eps)
	tmp = 0
	if eps <= -3.4e-9:
		tmp = (t_0 / (1.0 - (math.tan(x) / (1.0 / math.tan(eps))))) - math.tan(x)
	elif eps <= 5.2e-9:
		tmp = eps + (eps * math.pow(math.tan(x), 2.0))
	else:
		tmp = (t_0 * (1.0 / (1.0 - (math.tan(x) * math.tan(eps))))) - math.tan(x)
	return tmp
function code(x, eps)
	t_0 = Float64(tan(x) + tan(eps))
	tmp = 0.0
	if (eps <= -3.4e-9)
		tmp = Float64(Float64(t_0 / Float64(1.0 - Float64(tan(x) / Float64(1.0 / tan(eps))))) - tan(x));
	elseif (eps <= 5.2e-9)
		tmp = Float64(eps + Float64(eps * (tan(x) ^ 2.0)));
	else
		tmp = Float64(Float64(t_0 * Float64(1.0 / Float64(1.0 - Float64(tan(x) * tan(eps))))) - tan(x));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	t_0 = tan(x) + tan(eps);
	tmp = 0.0;
	if (eps <= -3.4e-9)
		tmp = (t_0 / (1.0 - (tan(x) / (1.0 / tan(eps))))) - tan(x);
	elseif (eps <= 5.2e-9)
		tmp = eps + (eps * (tan(x) ^ 2.0));
	else
		tmp = (t_0 * (1.0 / (1.0 - (tan(x) * tan(eps))))) - tan(x);
	end
	tmp_2 = tmp;
end
code[x_, eps_] := Block[{t$95$0 = N[(N[Tan[x], $MachinePrecision] + N[Tan[eps], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[eps, -3.4e-9], N[(N[(t$95$0 / N[(1.0 - N[(N[Tan[x], $MachinePrecision] / N[(1.0 / N[Tan[eps], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Tan[x], $MachinePrecision]), $MachinePrecision], If[LessEqual[eps, 5.2e-9], N[(eps + N[(eps * N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(t$95$0 * N[(1.0 / N[(1.0 - N[(N[Tan[x], $MachinePrecision] * N[Tan[eps], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Tan[x], $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \tan x + \tan \varepsilon\\
\mathbf{if}\;\varepsilon \leq -3.4 \cdot 10^{-9}:\\
\;\;\;\;\frac{t_0}{1 - \frac{\tan x}{\frac{1}{\tan \varepsilon}}} - \tan x\\

\mathbf{elif}\;\varepsilon \leq 5.2 \cdot 10^{-9}:\\
\;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\

\mathbf{else}:\\
\;\;\;\;t_0 \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if eps < -3.3999999999999998e-9

    1. Initial program 44.9%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum99.5%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv99.5%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. fma-neg99.5%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    3. Applied egg-rr99.5%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    4. Step-by-step derivation
      1. fma-neg99.5%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
      2. associate-*r/99.5%

        \[\leadsto \color{blue}{\frac{\left(\tan x + \tan \varepsilon\right) \cdot 1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. *-rgt-identity99.5%

        \[\leadsto \frac{\color{blue}{\tan x + \tan \varepsilon}}{1 - \tan x \cdot \tan \varepsilon} - \tan x \]
    5. Simplified99.5%

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
    6. Step-by-step derivation
      1. tan-quot99.3%

        \[\leadsto \frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \color{blue}{\frac{\sin \varepsilon}{\cos \varepsilon}}} - \tan x \]
      2. clear-num99.4%

        \[\leadsto \frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \color{blue}{\frac{1}{\frac{\cos \varepsilon}{\sin \varepsilon}}}} - \tan x \]
      3. un-div-inv99.4%

        \[\leadsto \frac{\tan x + \tan \varepsilon}{1 - \color{blue}{\frac{\tan x}{\frac{\cos \varepsilon}{\sin \varepsilon}}}} - \tan x \]
      4. clear-num99.3%

        \[\leadsto \frac{\tan x + \tan \varepsilon}{1 - \frac{\tan x}{\color{blue}{\frac{1}{\frac{\sin \varepsilon}{\cos \varepsilon}}}}} - \tan x \]
      5. tan-quot99.5%

        \[\leadsto \frac{\tan x + \tan \varepsilon}{1 - \frac{\tan x}{\frac{1}{\color{blue}{\tan \varepsilon}}}} - \tan x \]
    7. Applied egg-rr99.5%

      \[\leadsto \frac{\tan x + \tan \varepsilon}{1 - \color{blue}{\frac{\tan x}{\frac{1}{\tan \varepsilon}}}} - \tan x \]

    if -3.3999999999999998e-9 < eps < 5.2000000000000002e-9

    1. Initial program 28.0%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum28.5%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv28.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. fma-neg28.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    3. Applied egg-rr28.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    4. Step-by-step derivation
      1. fma-neg28.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
      2. associate-*r/28.5%

        \[\leadsto \color{blue}{\frac{\left(\tan x + \tan \varepsilon\right) \cdot 1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. *-rgt-identity28.5%

        \[\leadsto \frac{\color{blue}{\tan x + \tan \varepsilon}}{1 - \tan x \cdot \tan \varepsilon} - \tan x \]
    5. Simplified28.5%

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
    6. Taylor expanded in eps around 0 99.5%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    7. Step-by-step derivation
      1. cancel-sign-sub-inv99.5%

        \[\leadsto \varepsilon \cdot \color{blue}{\left(1 + \left(--1\right) \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
      2. metadata-eval99.5%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{1} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
      3. *-lft-identity99.5%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{\frac{{\sin x}^{2}}{{\cos x}^{2}}}\right) \]
    8. Simplified99.5%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 + \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    9. Step-by-step derivation
      1. distribute-rgt-in99.7%

        \[\leadsto \color{blue}{1 \cdot \varepsilon + \frac{{\sin x}^{2}}{{\cos x}^{2}} \cdot \varepsilon} \]
      2. *-un-lft-identity99.7%

        \[\leadsto \color{blue}{\varepsilon} + \frac{{\sin x}^{2}}{{\cos x}^{2}} \cdot \varepsilon \]
      3. unpow299.7%

        \[\leadsto \varepsilon + \frac{\color{blue}{\sin x \cdot \sin x}}{{\cos x}^{2}} \cdot \varepsilon \]
      4. unpow299.7%

        \[\leadsto \varepsilon + \frac{\sin x \cdot \sin x}{\color{blue}{\cos x \cdot \cos x}} \cdot \varepsilon \]
      5. frac-times99.6%

        \[\leadsto \varepsilon + \color{blue}{\left(\frac{\sin x}{\cos x} \cdot \frac{\sin x}{\cos x}\right)} \cdot \varepsilon \]
      6. tan-quot99.7%

        \[\leadsto \varepsilon + \left(\color{blue}{\tan x} \cdot \frac{\sin x}{\cos x}\right) \cdot \varepsilon \]
      7. tan-quot99.7%

        \[\leadsto \varepsilon + \left(\tan x \cdot \color{blue}{\tan x}\right) \cdot \varepsilon \]
      8. pow299.7%

        \[\leadsto \varepsilon + \color{blue}{{\tan x}^{2}} \cdot \varepsilon \]
    10. Applied egg-rr99.7%

      \[\leadsto \color{blue}{\varepsilon + {\tan x}^{2} \cdot \varepsilon} \]

    if 5.2000000000000002e-9 < eps

    1. Initial program 51.7%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum99.3%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv99.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
    3. Applied egg-rr99.4%

      \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -3.4 \cdot 10^{-9}:\\ \;\;\;\;\frac{\tan x + \tan \varepsilon}{1 - \frac{\tan x}{\frac{1}{\tan \varepsilon}}} - \tan x\\ \mathbf{elif}\;\varepsilon \leq 5.2 \cdot 10^{-9}:\\ \;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\ \mathbf{else}:\\ \;\;\;\;\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x\\ \end{array} \]

Alternative 9: 99.4% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \tan x + \tan \varepsilon\\ \mathbf{if}\;\varepsilon \leq -4.6 \cdot 10^{-9}:\\ \;\;\;\;t_0 \cdot \frac{1}{1 - \frac{\tan x}{\frac{1}{\tan \varepsilon}}} - \tan x\\ \mathbf{elif}\;\varepsilon \leq 3.6 \cdot 10^{-9}:\\ \;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\ \mathbf{else}:\\ \;\;\;\;t_0 \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (+ (tan x) (tan eps))))
   (if (<= eps -4.6e-9)
     (- (* t_0 (/ 1.0 (- 1.0 (/ (tan x) (/ 1.0 (tan eps)))))) (tan x))
     (if (<= eps 3.6e-9)
       (+ eps (* eps (pow (tan x) 2.0)))
       (- (* t_0 (/ 1.0 (- 1.0 (* (tan x) (tan eps))))) (tan x))))))
double code(double x, double eps) {
	double t_0 = tan(x) + tan(eps);
	double tmp;
	if (eps <= -4.6e-9) {
		tmp = (t_0 * (1.0 / (1.0 - (tan(x) / (1.0 / tan(eps)))))) - tan(x);
	} else if (eps <= 3.6e-9) {
		tmp = eps + (eps * pow(tan(x), 2.0));
	} else {
		tmp = (t_0 * (1.0 / (1.0 - (tan(x) * tan(eps))))) - tan(x);
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: t_0
    real(8) :: tmp
    t_0 = tan(x) + tan(eps)
    if (eps <= (-4.6d-9)) then
        tmp = (t_0 * (1.0d0 / (1.0d0 - (tan(x) / (1.0d0 / tan(eps)))))) - tan(x)
    else if (eps <= 3.6d-9) then
        tmp = eps + (eps * (tan(x) ** 2.0d0))
    else
        tmp = (t_0 * (1.0d0 / (1.0d0 - (tan(x) * tan(eps))))) - tan(x)
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double t_0 = Math.tan(x) + Math.tan(eps);
	double tmp;
	if (eps <= -4.6e-9) {
		tmp = (t_0 * (1.0 / (1.0 - (Math.tan(x) / (1.0 / Math.tan(eps)))))) - Math.tan(x);
	} else if (eps <= 3.6e-9) {
		tmp = eps + (eps * Math.pow(Math.tan(x), 2.0));
	} else {
		tmp = (t_0 * (1.0 / (1.0 - (Math.tan(x) * Math.tan(eps))))) - Math.tan(x);
	}
	return tmp;
}
def code(x, eps):
	t_0 = math.tan(x) + math.tan(eps)
	tmp = 0
	if eps <= -4.6e-9:
		tmp = (t_0 * (1.0 / (1.0 - (math.tan(x) / (1.0 / math.tan(eps)))))) - math.tan(x)
	elif eps <= 3.6e-9:
		tmp = eps + (eps * math.pow(math.tan(x), 2.0))
	else:
		tmp = (t_0 * (1.0 / (1.0 - (math.tan(x) * math.tan(eps))))) - math.tan(x)
	return tmp
function code(x, eps)
	t_0 = Float64(tan(x) + tan(eps))
	tmp = 0.0
	if (eps <= -4.6e-9)
		tmp = Float64(Float64(t_0 * Float64(1.0 / Float64(1.0 - Float64(tan(x) / Float64(1.0 / tan(eps)))))) - tan(x));
	elseif (eps <= 3.6e-9)
		tmp = Float64(eps + Float64(eps * (tan(x) ^ 2.0)));
	else
		tmp = Float64(Float64(t_0 * Float64(1.0 / Float64(1.0 - Float64(tan(x) * tan(eps))))) - tan(x));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	t_0 = tan(x) + tan(eps);
	tmp = 0.0;
	if (eps <= -4.6e-9)
		tmp = (t_0 * (1.0 / (1.0 - (tan(x) / (1.0 / tan(eps)))))) - tan(x);
	elseif (eps <= 3.6e-9)
		tmp = eps + (eps * (tan(x) ^ 2.0));
	else
		tmp = (t_0 * (1.0 / (1.0 - (tan(x) * tan(eps))))) - tan(x);
	end
	tmp_2 = tmp;
end
code[x_, eps_] := Block[{t$95$0 = N[(N[Tan[x], $MachinePrecision] + N[Tan[eps], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[eps, -4.6e-9], N[(N[(t$95$0 * N[(1.0 / N[(1.0 - N[(N[Tan[x], $MachinePrecision] / N[(1.0 / N[Tan[eps], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Tan[x], $MachinePrecision]), $MachinePrecision], If[LessEqual[eps, 3.6e-9], N[(eps + N[(eps * N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(t$95$0 * N[(1.0 / N[(1.0 - N[(N[Tan[x], $MachinePrecision] * N[Tan[eps], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Tan[x], $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \tan x + \tan \varepsilon\\
\mathbf{if}\;\varepsilon \leq -4.6 \cdot 10^{-9}:\\
\;\;\;\;t_0 \cdot \frac{1}{1 - \frac{\tan x}{\frac{1}{\tan \varepsilon}}} - \tan x\\

\mathbf{elif}\;\varepsilon \leq 3.6 \cdot 10^{-9}:\\
\;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\

\mathbf{else}:\\
\;\;\;\;t_0 \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if eps < -4.5999999999999998e-9

    1. Initial program 44.9%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum99.5%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv99.5%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
    3. Applied egg-rr99.5%

      \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
    4. Step-by-step derivation
      1. tan-quot99.3%

        \[\leadsto \frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \color{blue}{\frac{\sin \varepsilon}{\cos \varepsilon}}} - \tan x \]
      2. clear-num99.4%

        \[\leadsto \frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \color{blue}{\frac{1}{\frac{\cos \varepsilon}{\sin \varepsilon}}}} - \tan x \]
      3. un-div-inv99.4%

        \[\leadsto \frac{\tan x + \tan \varepsilon}{1 - \color{blue}{\frac{\tan x}{\frac{\cos \varepsilon}{\sin \varepsilon}}}} - \tan x \]
      4. clear-num99.3%

        \[\leadsto \frac{\tan x + \tan \varepsilon}{1 - \frac{\tan x}{\color{blue}{\frac{1}{\frac{\sin \varepsilon}{\cos \varepsilon}}}}} - \tan x \]
      5. tan-quot99.5%

        \[\leadsto \frac{\tan x + \tan \varepsilon}{1 - \frac{\tan x}{\frac{1}{\color{blue}{\tan \varepsilon}}}} - \tan x \]
    5. Applied egg-rr99.5%

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

    if -4.5999999999999998e-9 < eps < 3.6e-9

    1. Initial program 28.0%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum28.5%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv28.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. fma-neg28.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    3. Applied egg-rr28.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    4. Step-by-step derivation
      1. fma-neg28.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
      2. associate-*r/28.5%

        \[\leadsto \color{blue}{\frac{\left(\tan x + \tan \varepsilon\right) \cdot 1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. *-rgt-identity28.5%

        \[\leadsto \frac{\color{blue}{\tan x + \tan \varepsilon}}{1 - \tan x \cdot \tan \varepsilon} - \tan x \]
    5. Simplified28.5%

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
    6. Taylor expanded in eps around 0 99.5%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    7. Step-by-step derivation
      1. cancel-sign-sub-inv99.5%

        \[\leadsto \varepsilon \cdot \color{blue}{\left(1 + \left(--1\right) \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
      2. metadata-eval99.5%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{1} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
      3. *-lft-identity99.5%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{\frac{{\sin x}^{2}}{{\cos x}^{2}}}\right) \]
    8. Simplified99.5%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 + \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    9. Step-by-step derivation
      1. distribute-rgt-in99.7%

        \[\leadsto \color{blue}{1 \cdot \varepsilon + \frac{{\sin x}^{2}}{{\cos x}^{2}} \cdot \varepsilon} \]
      2. *-un-lft-identity99.7%

        \[\leadsto \color{blue}{\varepsilon} + \frac{{\sin x}^{2}}{{\cos x}^{2}} \cdot \varepsilon \]
      3. unpow299.7%

        \[\leadsto \varepsilon + \frac{\color{blue}{\sin x \cdot \sin x}}{{\cos x}^{2}} \cdot \varepsilon \]
      4. unpow299.7%

        \[\leadsto \varepsilon + \frac{\sin x \cdot \sin x}{\color{blue}{\cos x \cdot \cos x}} \cdot \varepsilon \]
      5. frac-times99.6%

        \[\leadsto \varepsilon + \color{blue}{\left(\frac{\sin x}{\cos x} \cdot \frac{\sin x}{\cos x}\right)} \cdot \varepsilon \]
      6. tan-quot99.7%

        \[\leadsto \varepsilon + \left(\color{blue}{\tan x} \cdot \frac{\sin x}{\cos x}\right) \cdot \varepsilon \]
      7. tan-quot99.7%

        \[\leadsto \varepsilon + \left(\tan x \cdot \color{blue}{\tan x}\right) \cdot \varepsilon \]
      8. pow299.7%

        \[\leadsto \varepsilon + \color{blue}{{\tan x}^{2}} \cdot \varepsilon \]
    10. Applied egg-rr99.7%

      \[\leadsto \color{blue}{\varepsilon + {\tan x}^{2} \cdot \varepsilon} \]

    if 3.6e-9 < eps

    1. Initial program 51.7%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum99.3%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv99.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
    3. Applied egg-rr99.4%

      \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -4.6 \cdot 10^{-9}:\\ \;\;\;\;\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \frac{\tan x}{\frac{1}{\tan \varepsilon}}} - \tan x\\ \mathbf{elif}\;\varepsilon \leq 3.6 \cdot 10^{-9}:\\ \;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\ \mathbf{else}:\\ \;\;\;\;\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x\\ \end{array} \]

Alternative 10: 99.4% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\varepsilon \leq -1.4 \cdot 10^{-9} \lor \neg \left(\varepsilon \leq 5.8 \cdot 10^{-9}\right):\\ \;\;\;\;\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon} - \tan x\\ \mathbf{else}:\\ \;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (or (<= eps -1.4e-9) (not (<= eps 5.8e-9)))
   (- (/ (+ (tan x) (tan eps)) (- 1.0 (* (tan x) (tan eps)))) (tan x))
   (+ eps (* eps (pow (tan x) 2.0)))))
double code(double x, double eps) {
	double tmp;
	if ((eps <= -1.4e-9) || !(eps <= 5.8e-9)) {
		tmp = ((tan(x) + tan(eps)) / (1.0 - (tan(x) * tan(eps)))) - tan(x);
	} else {
		tmp = eps + (eps * pow(tan(x), 2.0));
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if ((eps <= (-1.4d-9)) .or. (.not. (eps <= 5.8d-9))) then
        tmp = ((tan(x) + tan(eps)) / (1.0d0 - (tan(x) * tan(eps)))) - tan(x)
    else
        tmp = eps + (eps * (tan(x) ** 2.0d0))
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if ((eps <= -1.4e-9) || !(eps <= 5.8e-9)) {
		tmp = ((Math.tan(x) + Math.tan(eps)) / (1.0 - (Math.tan(x) * Math.tan(eps)))) - Math.tan(x);
	} else {
		tmp = eps + (eps * Math.pow(Math.tan(x), 2.0));
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if (eps <= -1.4e-9) or not (eps <= 5.8e-9):
		tmp = ((math.tan(x) + math.tan(eps)) / (1.0 - (math.tan(x) * math.tan(eps)))) - math.tan(x)
	else:
		tmp = eps + (eps * math.pow(math.tan(x), 2.0))
	return tmp
function code(x, eps)
	tmp = 0.0
	if ((eps <= -1.4e-9) || !(eps <= 5.8e-9))
		tmp = Float64(Float64(Float64(tan(x) + tan(eps)) / Float64(1.0 - Float64(tan(x) * tan(eps)))) - tan(x));
	else
		tmp = Float64(eps + Float64(eps * (tan(x) ^ 2.0)));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if ((eps <= -1.4e-9) || ~((eps <= 5.8e-9)))
		tmp = ((tan(x) + tan(eps)) / (1.0 - (tan(x) * tan(eps)))) - tan(x);
	else
		tmp = eps + (eps * (tan(x) ^ 2.0));
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[Or[LessEqual[eps, -1.4e-9], N[Not[LessEqual[eps, 5.8e-9]], $MachinePrecision]], N[(N[(N[(N[Tan[x], $MachinePrecision] + N[Tan[eps], $MachinePrecision]), $MachinePrecision] / N[(1.0 - N[(N[Tan[x], $MachinePrecision] * N[Tan[eps], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Tan[x], $MachinePrecision]), $MachinePrecision], N[(eps + N[(eps * N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\varepsilon \leq -1.4 \cdot 10^{-9} \lor \neg \left(\varepsilon \leq 5.8 \cdot 10^{-9}\right):\\
\;\;\;\;\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon} - \tan x\\

\mathbf{else}:\\
\;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if eps < -1.39999999999999992e-9 or 5.79999999999999982e-9 < eps

    1. Initial program 48.3%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum99.4%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv99.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. fma-neg99.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    3. Applied egg-rr99.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    4. Step-by-step derivation
      1. fma-neg99.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
      2. associate-*r/99.4%

        \[\leadsto \color{blue}{\frac{\left(\tan x + \tan \varepsilon\right) \cdot 1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. *-rgt-identity99.4%

        \[\leadsto \frac{\color{blue}{\tan x + \tan \varepsilon}}{1 - \tan x \cdot \tan \varepsilon} - \tan x \]
    5. Simplified99.4%

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]

    if -1.39999999999999992e-9 < eps < 5.79999999999999982e-9

    1. Initial program 28.0%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum28.5%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv28.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. fma-neg28.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    3. Applied egg-rr28.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    4. Step-by-step derivation
      1. fma-neg28.4%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
      2. associate-*r/28.5%

        \[\leadsto \color{blue}{\frac{\left(\tan x + \tan \varepsilon\right) \cdot 1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. *-rgt-identity28.5%

        \[\leadsto \frac{\color{blue}{\tan x + \tan \varepsilon}}{1 - \tan x \cdot \tan \varepsilon} - \tan x \]
    5. Simplified28.5%

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
    6. Taylor expanded in eps around 0 99.5%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    7. Step-by-step derivation
      1. cancel-sign-sub-inv99.5%

        \[\leadsto \varepsilon \cdot \color{blue}{\left(1 + \left(--1\right) \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
      2. metadata-eval99.5%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{1} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
      3. *-lft-identity99.5%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{\frac{{\sin x}^{2}}{{\cos x}^{2}}}\right) \]
    8. Simplified99.5%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 + \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    9. Step-by-step derivation
      1. distribute-rgt-in99.7%

        \[\leadsto \color{blue}{1 \cdot \varepsilon + \frac{{\sin x}^{2}}{{\cos x}^{2}} \cdot \varepsilon} \]
      2. *-un-lft-identity99.7%

        \[\leadsto \color{blue}{\varepsilon} + \frac{{\sin x}^{2}}{{\cos x}^{2}} \cdot \varepsilon \]
      3. unpow299.7%

        \[\leadsto \varepsilon + \frac{\color{blue}{\sin x \cdot \sin x}}{{\cos x}^{2}} \cdot \varepsilon \]
      4. unpow299.7%

        \[\leadsto \varepsilon + \frac{\sin x \cdot \sin x}{\color{blue}{\cos x \cdot \cos x}} \cdot \varepsilon \]
      5. frac-times99.6%

        \[\leadsto \varepsilon + \color{blue}{\left(\frac{\sin x}{\cos x} \cdot \frac{\sin x}{\cos x}\right)} \cdot \varepsilon \]
      6. tan-quot99.7%

        \[\leadsto \varepsilon + \left(\color{blue}{\tan x} \cdot \frac{\sin x}{\cos x}\right) \cdot \varepsilon \]
      7. tan-quot99.7%

        \[\leadsto \varepsilon + \left(\tan x \cdot \color{blue}{\tan x}\right) \cdot \varepsilon \]
      8. pow299.7%

        \[\leadsto \varepsilon + \color{blue}{{\tan x}^{2}} \cdot \varepsilon \]
    10. Applied egg-rr99.7%

      \[\leadsto \color{blue}{\varepsilon + {\tan x}^{2} \cdot \varepsilon} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -1.4 \cdot 10^{-9} \lor \neg \left(\varepsilon \leq 5.8 \cdot 10^{-9}\right):\\ \;\;\;\;\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon} - \tan x\\ \mathbf{else}:\\ \;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\ \end{array} \]

Alternative 11: 77.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.0105:\\ \;\;\;\;\tan \varepsilon\\ \mathbf{elif}\;\varepsilon \leq 0.118:\\ \;\;\;\;\varepsilon \cdot \left(1 + {\tan x}^{2}\right)\\ \mathbf{else}:\\ \;\;\;\;\tan \varepsilon\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (<= eps -0.0105)
   (tan eps)
   (if (<= eps 0.118) (* eps (+ 1.0 (pow (tan x) 2.0))) (tan eps))))
double code(double x, double eps) {
	double tmp;
	if (eps <= -0.0105) {
		tmp = tan(eps);
	} else if (eps <= 0.118) {
		tmp = eps * (1.0 + pow(tan(x), 2.0));
	} else {
		tmp = tan(eps);
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if (eps <= (-0.0105d0)) then
        tmp = tan(eps)
    else if (eps <= 0.118d0) then
        tmp = eps * (1.0d0 + (tan(x) ** 2.0d0))
    else
        tmp = tan(eps)
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if (eps <= -0.0105) {
		tmp = Math.tan(eps);
	} else if (eps <= 0.118) {
		tmp = eps * (1.0 + Math.pow(Math.tan(x), 2.0));
	} else {
		tmp = Math.tan(eps);
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if eps <= -0.0105:
		tmp = math.tan(eps)
	elif eps <= 0.118:
		tmp = eps * (1.0 + math.pow(math.tan(x), 2.0))
	else:
		tmp = math.tan(eps)
	return tmp
function code(x, eps)
	tmp = 0.0
	if (eps <= -0.0105)
		tmp = tan(eps);
	elseif (eps <= 0.118)
		tmp = Float64(eps * Float64(1.0 + (tan(x) ^ 2.0)));
	else
		tmp = tan(eps);
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if (eps <= -0.0105)
		tmp = tan(eps);
	elseif (eps <= 0.118)
		tmp = eps * (1.0 + (tan(x) ^ 2.0));
	else
		tmp = tan(eps);
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[LessEqual[eps, -0.0105], N[Tan[eps], $MachinePrecision], If[LessEqual[eps, 0.118], N[(eps * N[(1.0 + N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[Tan[eps], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\varepsilon \leq -0.0105:\\
\;\;\;\;\tan \varepsilon\\

\mathbf{elif}\;\varepsilon \leq 0.118:\\
\;\;\;\;\varepsilon \cdot \left(1 + {\tan x}^{2}\right)\\

\mathbf{else}:\\
\;\;\;\;\tan \varepsilon\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if eps < -0.0105000000000000007 or 0.11799999999999999 < eps

    1. Initial program 49.3%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Taylor expanded in x around 0 52.8%

      \[\leadsto \color{blue}{\frac{\sin \varepsilon}{\cos \varepsilon}} \]
    3. Step-by-step derivation
      1. tan-quot53.0%

        \[\leadsto \color{blue}{\tan \varepsilon} \]
      2. expm1-log1p-u40.8%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\tan \varepsilon\right)\right)} \]
      3. expm1-udef40.4%

        \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\tan \varepsilon\right)} - 1} \]
    4. Applied egg-rr40.4%

      \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\tan \varepsilon\right)} - 1} \]
    5. Step-by-step derivation
      1. expm1-def40.8%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\tan \varepsilon\right)\right)} \]
      2. expm1-log1p53.0%

        \[\leadsto \color{blue}{\tan \varepsilon} \]
    6. Simplified53.0%

      \[\leadsto \color{blue}{\tan \varepsilon} \]

    if -0.0105000000000000007 < eps < 0.11799999999999999

    1. Initial program 27.4%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum30.0%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv30.0%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. fma-neg30.0%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    3. Applied egg-rr30.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    4. Step-by-step derivation
      1. fma-neg30.0%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
      2. associate-*r/30.0%

        \[\leadsto \color{blue}{\frac{\left(\tan x + \tan \varepsilon\right) \cdot 1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. *-rgt-identity30.0%

        \[\leadsto \frac{\color{blue}{\tan x + \tan \varepsilon}}{1 - \tan x \cdot \tan \varepsilon} - \tan x \]
    5. Simplified30.0%

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
    6. Taylor expanded in eps around 0 97.9%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    7. Step-by-step derivation
      1. cancel-sign-sub-inv97.9%

        \[\leadsto \varepsilon \cdot \color{blue}{\left(1 + \left(--1\right) \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
      2. metadata-eval97.9%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{1} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
      3. *-lft-identity97.9%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{\frac{{\sin x}^{2}}{{\cos x}^{2}}}\right) \]
    8. Simplified97.9%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 + \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    9. Step-by-step derivation
      1. unpow297.9%

        \[\leadsto \varepsilon \cdot \left(1 + \frac{\color{blue}{\sin x \cdot \sin x}}{{\cos x}^{2}}\right) \]
      2. unpow297.9%

        \[\leadsto \varepsilon \cdot \left(1 + \frac{\sin x \cdot \sin x}{\color{blue}{\cos x \cdot \cos x}}\right) \]
      3. frac-times97.8%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{\frac{\sin x}{\cos x} \cdot \frac{\sin x}{\cos x}}\right) \]
      4. tan-quot97.9%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{\tan x} \cdot \frac{\sin x}{\cos x}\right) \]
      5. tan-quot97.9%

        \[\leadsto \varepsilon \cdot \left(1 + \tan x \cdot \color{blue}{\tan x}\right) \]
    10. Applied egg-rr97.9%

      \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{\tan x \cdot \tan x}\right) \]
    11. Step-by-step derivation
      1. unpow297.9%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{{\tan x}^{2}}\right) \]
    12. Simplified97.9%

      \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{{\tan x}^{2}}\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification75.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.0105:\\ \;\;\;\;\tan \varepsilon\\ \mathbf{elif}\;\varepsilon \leq 0.118:\\ \;\;\;\;\varepsilon \cdot \left(1 + {\tan x}^{2}\right)\\ \mathbf{else}:\\ \;\;\;\;\tan \varepsilon\\ \end{array} \]

Alternative 12: 77.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.0105:\\ \;\;\;\;\tan \varepsilon\\ \mathbf{elif}\;\varepsilon \leq 0.118:\\ \;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\ \mathbf{else}:\\ \;\;\;\;\tan \varepsilon\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (<= eps -0.0105)
   (tan eps)
   (if (<= eps 0.118) (+ eps (* eps (pow (tan x) 2.0))) (tan eps))))
double code(double x, double eps) {
	double tmp;
	if (eps <= -0.0105) {
		tmp = tan(eps);
	} else if (eps <= 0.118) {
		tmp = eps + (eps * pow(tan(x), 2.0));
	} else {
		tmp = tan(eps);
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if (eps <= (-0.0105d0)) then
        tmp = tan(eps)
    else if (eps <= 0.118d0) then
        tmp = eps + (eps * (tan(x) ** 2.0d0))
    else
        tmp = tan(eps)
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if (eps <= -0.0105) {
		tmp = Math.tan(eps);
	} else if (eps <= 0.118) {
		tmp = eps + (eps * Math.pow(Math.tan(x), 2.0));
	} else {
		tmp = Math.tan(eps);
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if eps <= -0.0105:
		tmp = math.tan(eps)
	elif eps <= 0.118:
		tmp = eps + (eps * math.pow(math.tan(x), 2.0))
	else:
		tmp = math.tan(eps)
	return tmp
function code(x, eps)
	tmp = 0.0
	if (eps <= -0.0105)
		tmp = tan(eps);
	elseif (eps <= 0.118)
		tmp = Float64(eps + Float64(eps * (tan(x) ^ 2.0)));
	else
		tmp = tan(eps);
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if (eps <= -0.0105)
		tmp = tan(eps);
	elseif (eps <= 0.118)
		tmp = eps + (eps * (tan(x) ^ 2.0));
	else
		tmp = tan(eps);
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[LessEqual[eps, -0.0105], N[Tan[eps], $MachinePrecision], If[LessEqual[eps, 0.118], N[(eps + N[(eps * N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[Tan[eps], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\varepsilon \leq -0.0105:\\
\;\;\;\;\tan \varepsilon\\

\mathbf{elif}\;\varepsilon \leq 0.118:\\
\;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\

\mathbf{else}:\\
\;\;\;\;\tan \varepsilon\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if eps < -0.0105000000000000007 or 0.11799999999999999 < eps

    1. Initial program 49.3%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Taylor expanded in x around 0 52.8%

      \[\leadsto \color{blue}{\frac{\sin \varepsilon}{\cos \varepsilon}} \]
    3. Step-by-step derivation
      1. tan-quot53.0%

        \[\leadsto \color{blue}{\tan \varepsilon} \]
      2. expm1-log1p-u40.8%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\tan \varepsilon\right)\right)} \]
      3. expm1-udef40.4%

        \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\tan \varepsilon\right)} - 1} \]
    4. Applied egg-rr40.4%

      \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\tan \varepsilon\right)} - 1} \]
    5. Step-by-step derivation
      1. expm1-def40.8%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\tan \varepsilon\right)\right)} \]
      2. expm1-log1p53.0%

        \[\leadsto \color{blue}{\tan \varepsilon} \]
    6. Simplified53.0%

      \[\leadsto \color{blue}{\tan \varepsilon} \]

    if -0.0105000000000000007 < eps < 0.11799999999999999

    1. Initial program 27.4%

      \[\tan \left(x + \varepsilon\right) - \tan x \]
    2. Step-by-step derivation
      1. tan-sum30.0%

        \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      2. div-inv30.0%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. fma-neg30.0%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    3. Applied egg-rr30.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
    4. Step-by-step derivation
      1. fma-neg30.0%

        \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
      2. associate-*r/30.0%

        \[\leadsto \color{blue}{\frac{\left(\tan x + \tan \varepsilon\right) \cdot 1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
      3. *-rgt-identity30.0%

        \[\leadsto \frac{\color{blue}{\tan x + \tan \varepsilon}}{1 - \tan x \cdot \tan \varepsilon} - \tan x \]
    5. Simplified30.0%

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
    6. Taylor expanded in eps around 0 97.9%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    7. Step-by-step derivation
      1. cancel-sign-sub-inv97.9%

        \[\leadsto \varepsilon \cdot \color{blue}{\left(1 + \left(--1\right) \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
      2. metadata-eval97.9%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{1} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
      3. *-lft-identity97.9%

        \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{\frac{{\sin x}^{2}}{{\cos x}^{2}}}\right) \]
    8. Simplified97.9%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(1 + \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
    9. Step-by-step derivation
      1. distribute-rgt-in98.0%

        \[\leadsto \color{blue}{1 \cdot \varepsilon + \frac{{\sin x}^{2}}{{\cos x}^{2}} \cdot \varepsilon} \]
      2. *-un-lft-identity98.0%

        \[\leadsto \color{blue}{\varepsilon} + \frac{{\sin x}^{2}}{{\cos x}^{2}} \cdot \varepsilon \]
      3. unpow298.0%

        \[\leadsto \varepsilon + \frac{\color{blue}{\sin x \cdot \sin x}}{{\cos x}^{2}} \cdot \varepsilon \]
      4. unpow298.0%

        \[\leadsto \varepsilon + \frac{\sin x \cdot \sin x}{\color{blue}{\cos x \cdot \cos x}} \cdot \varepsilon \]
      5. frac-times98.0%

        \[\leadsto \varepsilon + \color{blue}{\left(\frac{\sin x}{\cos x} \cdot \frac{\sin x}{\cos x}\right)} \cdot \varepsilon \]
      6. tan-quot98.0%

        \[\leadsto \varepsilon + \left(\color{blue}{\tan x} \cdot \frac{\sin x}{\cos x}\right) \cdot \varepsilon \]
      7. tan-quot98.0%

        \[\leadsto \varepsilon + \left(\tan x \cdot \color{blue}{\tan x}\right) \cdot \varepsilon \]
      8. pow298.0%

        \[\leadsto \varepsilon + \color{blue}{{\tan x}^{2}} \cdot \varepsilon \]
    10. Applied egg-rr98.0%

      \[\leadsto \color{blue}{\varepsilon + {\tan x}^{2} \cdot \varepsilon} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification75.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.0105:\\ \;\;\;\;\tan \varepsilon\\ \mathbf{elif}\;\varepsilon \leq 0.118:\\ \;\;\;\;\varepsilon + \varepsilon \cdot {\tan x}^{2}\\ \mathbf{else}:\\ \;\;\;\;\tan \varepsilon\\ \end{array} \]

Alternative 13: 34.6% accurate, 2.0× speedup?

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

\\
\sin \varepsilon
\end{array}
Derivation
  1. Initial program 38.5%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in x around 0 52.4%

    \[\leadsto \color{blue}{\frac{\sin \varepsilon}{\cos \varepsilon}} \]
  3. Step-by-step derivation
    1. add-sqr-sqrt28.7%

      \[\leadsto \frac{\color{blue}{\sqrt{\sin \varepsilon} \cdot \sqrt{\sin \varepsilon}}}{\cos \varepsilon} \]
    2. sqrt-unprod25.5%

      \[\leadsto \frac{\color{blue}{\sqrt{\sin \varepsilon \cdot \sin \varepsilon}}}{\cos \varepsilon} \]
    3. pow225.5%

      \[\leadsto \frac{\sqrt{\color{blue}{{\sin \varepsilon}^{2}}}}{\cos \varepsilon} \]
  4. Applied egg-rr25.5%

    \[\leadsto \frac{\color{blue}{\sqrt{{\sin \varepsilon}^{2}}}}{\cos \varepsilon} \]
  5. Step-by-step derivation
    1. unpow225.5%

      \[\leadsto \frac{\sqrt{\color{blue}{\sin \varepsilon \cdot \sin \varepsilon}}}{\cos \varepsilon} \]
    2. rem-sqrt-square30.6%

      \[\leadsto \frac{\color{blue}{\left|\sin \varepsilon\right|}}{\cos \varepsilon} \]
  6. Simplified30.6%

    \[\leadsto \frac{\color{blue}{\left|\sin \varepsilon\right|}}{\cos \varepsilon} \]
  7. Taylor expanded in eps around 0 21.3%

    \[\leadsto \color{blue}{\left|\sin \varepsilon\right|} \]
  8. Step-by-step derivation
    1. rem-square-sqrt17.5%

      \[\leadsto \left|\color{blue}{\sqrt{\sin \varepsilon} \cdot \sqrt{\sin \varepsilon}}\right| \]
    2. fabs-sqr17.5%

      \[\leadsto \color{blue}{\sqrt{\sin \varepsilon} \cdot \sqrt{\sin \varepsilon}} \]
    3. rem-square-sqrt30.9%

      \[\leadsto \color{blue}{\sin \varepsilon} \]
  9. Simplified30.9%

    \[\leadsto \color{blue}{\sin \varepsilon} \]
  10. Final simplification30.9%

    \[\leadsto \sin \varepsilon \]

Alternative 14: 57.9% accurate, 2.0× speedup?

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

\\
\tan \varepsilon
\end{array}
Derivation
  1. Initial program 38.5%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in x around 0 52.4%

    \[\leadsto \color{blue}{\frac{\sin \varepsilon}{\cos \varepsilon}} \]
  3. Step-by-step derivation
    1. tan-quot52.5%

      \[\leadsto \color{blue}{\tan \varepsilon} \]
    2. expm1-log1p-u46.3%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\tan \varepsilon\right)\right)} \]
    3. expm1-udef23.5%

      \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\tan \varepsilon\right)} - 1} \]
  4. Applied egg-rr23.5%

    \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\tan \varepsilon\right)} - 1} \]
  5. Step-by-step derivation
    1. expm1-def46.3%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\tan \varepsilon\right)\right)} \]
    2. expm1-log1p52.5%

      \[\leadsto \color{blue}{\tan \varepsilon} \]
  6. Simplified52.5%

    \[\leadsto \color{blue}{\tan \varepsilon} \]
  7. Final simplification52.5%

    \[\leadsto \tan \varepsilon \]

Alternative 15: 4.2% accurate, 205.0× speedup?

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

\\
0
\end{array}
Derivation
  1. Initial program 38.5%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Step-by-step derivation
    1. sub-neg38.5%

      \[\leadsto \color{blue}{\tan \left(x + \varepsilon\right) + \left(-\tan x\right)} \]
    2. +-commutative38.5%

      \[\leadsto \color{blue}{\left(-\tan x\right) + \tan \left(x + \varepsilon\right)} \]
    3. add-log-exp38.0%

      \[\leadsto \color{blue}{\log \left(e^{-\tan x}\right)} + \tan \left(x + \varepsilon\right) \]
    4. add-log-exp27.5%

      \[\leadsto \log \left(e^{-\tan x}\right) + \color{blue}{\log \left(e^{\tan \left(x + \varepsilon\right)}\right)} \]
    5. sum-log27.6%

      \[\leadsto \color{blue}{\log \left(e^{-\tan x} \cdot e^{\tan \left(x + \varepsilon\right)}\right)} \]
  3. Applied egg-rr27.6%

    \[\leadsto \color{blue}{\log \left(e^{-\tan x} \cdot e^{\tan \left(x + \varepsilon\right)}\right)} \]
  4. Taylor expanded in eps around 0 4.2%

    \[\leadsto \color{blue}{\log \left(e^{\frac{\sin x}{\cos x}} \cdot e^{-\frac{\sin x}{\cos x}}\right)} \]
  5. Step-by-step derivation
    1. exp-neg4.1%

      \[\leadsto \log \left(e^{\frac{\sin x}{\cos x}} \cdot \color{blue}{\frac{1}{e^{\frac{\sin x}{\cos x}}}}\right) \]
    2. rgt-mult-inverse4.1%

      \[\leadsto \log \color{blue}{1} \]
    3. metadata-eval4.1%

      \[\leadsto \color{blue}{0} \]
  6. Simplified4.1%

    \[\leadsto \color{blue}{0} \]
  7. Final simplification4.1%

    \[\leadsto 0 \]

Alternative 16: 30.9% accurate, 205.0× speedup?

\[\begin{array}{l} \\ \varepsilon \end{array} \]
(FPCore (x eps) :precision binary64 eps)
double code(double x, double eps) {
	return eps;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = eps
end function
public static double code(double x, double eps) {
	return eps;
}
def code(x, eps):
	return eps
function code(x, eps)
	return eps
end
function tmp = code(x, eps)
	tmp = eps;
end
code[x_, eps_] := eps
\begin{array}{l}

\\
\varepsilon
\end{array}
Derivation
  1. Initial program 38.5%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in x around 0 52.4%

    \[\leadsto \color{blue}{\frac{\sin \varepsilon}{\cos \varepsilon}} \]
  3. Taylor expanded in eps around 0 27.3%

    \[\leadsto \color{blue}{\varepsilon} \]
  4. Final simplification27.3%

    \[\leadsto \varepsilon \]

Developer target: 76.2% accurate, 0.7× speedup?

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

\\
\frac{\sin \varepsilon}{\cos x \cdot \cos \left(x + \varepsilon\right)}
\end{array}

Reproduce

?
herbie shell --seed 2023201 
(FPCore (x eps)
  :name "2tan (problem 3.3.2)"
  :precision binary64

  :herbie-target
  (/ (sin eps) (* (cos x) (cos (+ x eps))))

  (- (tan (+ x eps)) (tan x)))