sintan (problem 3.4.5)

Percentage Accurate: 50.6% → 99.5%
Time: 13.5s
Alternatives: 6
Speedup: 40.4×

Specification

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

\\
\frac{x - \sin x}{x - \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 6 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: 50.6% accurate, 1.0× speedup?

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

\\
\frac{x - \sin x}{x - \tan x}
\end{array}

Alternative 1: 99.5% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x - \sin x}{x - \tan x}\\ \mathbf{if}\;t_0 \leq 2:\\ \;\;\;\;t_0\\ \mathbf{else}:\\ \;\;\;\;-0.5\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (/ (- x (sin x)) (- x (tan x))))) (if (<= t_0 2.0) t_0 -0.5)))
double code(double x) {
	double t_0 = (x - sin(x)) / (x - tan(x));
	double tmp;
	if (t_0 <= 2.0) {
		tmp = t_0;
	} else {
		tmp = -0.5;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (x - sin(x)) / (x - tan(x))
    if (t_0 <= 2.0d0) then
        tmp = t_0
    else
        tmp = -0.5d0
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = (x - Math.sin(x)) / (x - Math.tan(x));
	double tmp;
	if (t_0 <= 2.0) {
		tmp = t_0;
	} else {
		tmp = -0.5;
	}
	return tmp;
}
def code(x):
	t_0 = (x - math.sin(x)) / (x - math.tan(x))
	tmp = 0
	if t_0 <= 2.0:
		tmp = t_0
	else:
		tmp = -0.5
	return tmp
function code(x)
	t_0 = Float64(Float64(x - sin(x)) / Float64(x - tan(x)))
	tmp = 0.0
	if (t_0 <= 2.0)
		tmp = t_0;
	else
		tmp = -0.5;
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = (x - sin(x)) / (x - tan(x));
	tmp = 0.0;
	if (t_0 <= 2.0)
		tmp = t_0;
	else
		tmp = -0.5;
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(N[(x - N[Sin[x], $MachinePrecision]), $MachinePrecision] / N[(x - N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 2.0], t$95$0, -0.5]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x - \sin x}{x - \tan x}\\
\mathbf{if}\;t_0 \leq 2:\\
\;\;\;\;t_0\\

\mathbf{else}:\\
\;\;\;\;-0.5\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 x (sin.f64 x)) (-.f64 x (tan.f64 x))) < 2

    1. Initial program 99.0%

      \[\frac{x - \sin x}{x - \tan x} \]

    if 2 < (/.f64 (-.f64 x (sin.f64 x)) (-.f64 x (tan.f64 x)))

    1. Initial program 0.0%

      \[\frac{x - \sin x}{x - \tan x} \]
    2. Step-by-step derivation
      1. sub-neg0.0%

        \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
      2. +-commutative0.0%

        \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
      3. neg-sub00.0%

        \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
      4. associate-+l-0.0%

        \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
      5. sub0-neg0.0%

        \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
      6. neg-mul-10.0%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
      7. sub-neg0.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
      8. +-commutative0.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
      9. neg-sub00.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
      10. associate-+l-0.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
      11. sub0-neg0.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
      12. neg-mul-10.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
      13. times-frac0.0%

        \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
      14. metadata-eval0.0%

        \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
      15. *-lft-identity0.0%

        \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    3. Simplified0.0%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    4. Taylor expanded in x around 0 100.0%

      \[\leadsto \color{blue}{-0.5} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x - \sin x}{x - \tan x} \leq 2:\\ \;\;\;\;\frac{x - \sin x}{x - \tan x}\\ \mathbf{else}:\\ \;\;\;\;-0.5\\ \end{array} \]

Alternative 2: 98.9% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -2.95:\\ \;\;\;\;1\\ \mathbf{elif}\;x \leq 2.8:\\ \;\;\;\;-0.5 + \left(0.225 \cdot \left(x \cdot x\right) + -0.009642857142857142 \cdot {x}^{4}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{x - \tan x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -2.95)
   1.0
   (if (<= x 2.8)
     (+ -0.5 (+ (* 0.225 (* x x)) (* -0.009642857142857142 (pow x 4.0))))
     (/ x (- x (tan x))))))
double code(double x) {
	double tmp;
	if (x <= -2.95) {
		tmp = 1.0;
	} else if (x <= 2.8) {
		tmp = -0.5 + ((0.225 * (x * x)) + (-0.009642857142857142 * pow(x, 4.0)));
	} else {
		tmp = x / (x - tan(x));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-2.95d0)) then
        tmp = 1.0d0
    else if (x <= 2.8d0) then
        tmp = (-0.5d0) + ((0.225d0 * (x * x)) + ((-0.009642857142857142d0) * (x ** 4.0d0)))
    else
        tmp = x / (x - tan(x))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -2.95) {
		tmp = 1.0;
	} else if (x <= 2.8) {
		tmp = -0.5 + ((0.225 * (x * x)) + (-0.009642857142857142 * Math.pow(x, 4.0)));
	} else {
		tmp = x / (x - Math.tan(x));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -2.95:
		tmp = 1.0
	elif x <= 2.8:
		tmp = -0.5 + ((0.225 * (x * x)) + (-0.009642857142857142 * math.pow(x, 4.0)))
	else:
		tmp = x / (x - math.tan(x))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -2.95)
		tmp = 1.0;
	elseif (x <= 2.8)
		tmp = Float64(-0.5 + Float64(Float64(0.225 * Float64(x * x)) + Float64(-0.009642857142857142 * (x ^ 4.0))));
	else
		tmp = Float64(x / Float64(x - tan(x)));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -2.95)
		tmp = 1.0;
	elseif (x <= 2.8)
		tmp = -0.5 + ((0.225 * (x * x)) + (-0.009642857142857142 * (x ^ 4.0)));
	else
		tmp = x / (x - tan(x));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -2.95], 1.0, If[LessEqual[x, 2.8], N[(-0.5 + N[(N[(0.225 * N[(x * x), $MachinePrecision]), $MachinePrecision] + N[(-0.009642857142857142 * N[Power[x, 4.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x / N[(x - N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -2.95:\\
\;\;\;\;1\\

\mathbf{elif}\;x \leq 2.8:\\
\;\;\;\;-0.5 + \left(0.225 \cdot \left(x \cdot x\right) + -0.009642857142857142 \cdot {x}^{4}\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{x}{x - \tan x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -2.9500000000000002

    1. Initial program 100.0%

      \[\frac{x - \sin x}{x - \tan x} \]
    2. Step-by-step derivation
      1. sub-neg100.0%

        \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
      2. +-commutative100.0%

        \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
      3. neg-sub0100.0%

        \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
      4. associate-+l-100.0%

        \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
      5. sub0-neg100.0%

        \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
      6. neg-mul-1100.0%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
      7. sub-neg100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
      8. +-commutative100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
      9. neg-sub0100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
      10. associate-+l-100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
      11. sub0-neg100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
      12. neg-mul-1100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
      13. times-frac100.0%

        \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
      14. metadata-eval100.0%

        \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
      15. *-lft-identity100.0%

        \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    4. Taylor expanded in x around inf 98.4%

      \[\leadsto \color{blue}{1} \]

    if -2.9500000000000002 < x < 2.7999999999999998

    1. Initial program 2.1%

      \[\frac{x - \sin x}{x - \tan x} \]
    2. Step-by-step derivation
      1. sub-neg2.1%

        \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
      2. +-commutative2.1%

        \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
      3. neg-sub02.1%

        \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
      4. associate-+l-2.1%

        \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
      5. sub0-neg2.1%

        \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
      6. neg-mul-12.1%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
      7. sub-neg2.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
      8. +-commutative2.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
      9. neg-sub02.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
      10. associate-+l-2.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
      11. sub0-neg2.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
      12. neg-mul-12.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
      13. times-frac2.1%

        \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
      14. metadata-eval2.1%

        \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
      15. *-lft-identity2.1%

        \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    3. Simplified2.1%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    4. Taylor expanded in x around 0 99.9%

      \[\leadsto \color{blue}{\left(0.225 \cdot {x}^{2} + -0.009642857142857142 \cdot {x}^{4}\right) - 0.5} \]
    5. Step-by-step derivation
      1. sub-neg99.9%

        \[\leadsto \color{blue}{\left(0.225 \cdot {x}^{2} + -0.009642857142857142 \cdot {x}^{4}\right) + \left(-0.5\right)} \]
      2. fma-def99.9%

        \[\leadsto \color{blue}{\mathsf{fma}\left(0.225, {x}^{2}, -0.009642857142857142 \cdot {x}^{4}\right)} + \left(-0.5\right) \]
      3. unpow299.9%

        \[\leadsto \mathsf{fma}\left(0.225, \color{blue}{x \cdot x}, -0.009642857142857142 \cdot {x}^{4}\right) + \left(-0.5\right) \]
      4. metadata-eval99.9%

        \[\leadsto \mathsf{fma}\left(0.225, x \cdot x, -0.009642857142857142 \cdot {x}^{4}\right) + \color{blue}{-0.5} \]
    6. Simplified99.9%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.225, x \cdot x, -0.009642857142857142 \cdot {x}^{4}\right) + -0.5} \]
    7. Step-by-step derivation
      1. fma-udef99.9%

        \[\leadsto \color{blue}{\left(0.225 \cdot \left(x \cdot x\right) + -0.009642857142857142 \cdot {x}^{4}\right)} + -0.5 \]
    8. Applied egg-rr99.9%

      \[\leadsto \color{blue}{\left(0.225 \cdot \left(x \cdot x\right) + -0.009642857142857142 \cdot {x}^{4}\right)} + -0.5 \]

    if 2.7999999999999998 < x

    1. Initial program 100.0%

      \[\frac{x - \sin x}{x - \tan x} \]
    2. Step-by-step derivation
      1. sub-neg100.0%

        \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
      2. +-commutative100.0%

        \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
      3. neg-sub0100.0%

        \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
      4. associate-+l-100.0%

        \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
      5. sub0-neg100.0%

        \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
      6. neg-mul-1100.0%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
      7. sub-neg100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
      8. +-commutative100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
      9. neg-sub0100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
      10. associate-+l-100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
      11. sub0-neg100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
      12. neg-mul-1100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
      13. times-frac100.0%

        \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
      14. metadata-eval100.0%

        \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
      15. *-lft-identity100.0%

        \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    4. Taylor expanded in x around inf 98.6%

      \[\leadsto \frac{\color{blue}{-1 \cdot x}}{\tan x - x} \]
    5. Step-by-step derivation
      1. neg-mul-198.6%

        \[\leadsto \frac{\color{blue}{-x}}{\tan x - x} \]
    6. Simplified98.6%

      \[\leadsto \frac{\color{blue}{-x}}{\tan x - x} \]
    7. Step-by-step derivation
      1. frac-2neg98.6%

        \[\leadsto \color{blue}{\frac{-\left(-x\right)}{-\left(\tan x - x\right)}} \]
      2. div-inv98.4%

        \[\leadsto \color{blue}{\left(-\left(-x\right)\right) \cdot \frac{1}{-\left(\tan x - x\right)}} \]
      3. remove-double-neg98.4%

        \[\leadsto \color{blue}{x} \cdot \frac{1}{-\left(\tan x - x\right)} \]
      4. sub-neg98.4%

        \[\leadsto x \cdot \frac{1}{-\color{blue}{\left(\tan x + \left(-x\right)\right)}} \]
      5. distribute-neg-in98.4%

        \[\leadsto x \cdot \frac{1}{\color{blue}{\left(-\tan x\right) + \left(-\left(-x\right)\right)}} \]
      6. remove-double-neg98.4%

        \[\leadsto x \cdot \frac{1}{\left(-\tan x\right) + \color{blue}{x}} \]
    8. Applied egg-rr98.4%

      \[\leadsto \color{blue}{x \cdot \frac{1}{\left(-\tan x\right) + x}} \]
    9. Step-by-step derivation
      1. associate-*r/98.6%

        \[\leadsto \color{blue}{\frac{x \cdot 1}{\left(-\tan x\right) + x}} \]
      2. *-rgt-identity98.6%

        \[\leadsto \frac{\color{blue}{x}}{\left(-\tan x\right) + x} \]
      3. +-commutative98.6%

        \[\leadsto \frac{x}{\color{blue}{x + \left(-\tan x\right)}} \]
      4. unsub-neg98.6%

        \[\leadsto \frac{x}{\color{blue}{x - \tan x}} \]
    10. Simplified98.6%

      \[\leadsto \color{blue}{\frac{x}{x - \tan x}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -2.95:\\ \;\;\;\;1\\ \mathbf{elif}\;x \leq 2.8:\\ \;\;\;\;-0.5 + \left(0.225 \cdot \left(x \cdot x\right) + -0.009642857142857142 \cdot {x}^{4}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{x - \tan x}\\ \end{array} \]

Alternative 3: 98.8% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -2.6:\\ \;\;\;\;1\\ \mathbf{elif}\;x \leq 2.3:\\ \;\;\;\;-0.5 + 0.225 \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{x - \tan x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -2.6)
   1.0
   (if (<= x 2.3) (+ -0.5 (* 0.225 (* x x))) (/ x (- x (tan x))))))
double code(double x) {
	double tmp;
	if (x <= -2.6) {
		tmp = 1.0;
	} else if (x <= 2.3) {
		tmp = -0.5 + (0.225 * (x * x));
	} else {
		tmp = x / (x - tan(x));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-2.6d0)) then
        tmp = 1.0d0
    else if (x <= 2.3d0) then
        tmp = (-0.5d0) + (0.225d0 * (x * x))
    else
        tmp = x / (x - tan(x))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -2.6) {
		tmp = 1.0;
	} else if (x <= 2.3) {
		tmp = -0.5 + (0.225 * (x * x));
	} else {
		tmp = x / (x - Math.tan(x));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -2.6:
		tmp = 1.0
	elif x <= 2.3:
		tmp = -0.5 + (0.225 * (x * x))
	else:
		tmp = x / (x - math.tan(x))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -2.6)
		tmp = 1.0;
	elseif (x <= 2.3)
		tmp = Float64(-0.5 + Float64(0.225 * Float64(x * x)));
	else
		tmp = Float64(x / Float64(x - tan(x)));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -2.6)
		tmp = 1.0;
	elseif (x <= 2.3)
		tmp = -0.5 + (0.225 * (x * x));
	else
		tmp = x / (x - tan(x));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -2.6], 1.0, If[LessEqual[x, 2.3], N[(-0.5 + N[(0.225 * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x / N[(x - N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -2.6:\\
\;\;\;\;1\\

\mathbf{elif}\;x \leq 2.3:\\
\;\;\;\;-0.5 + 0.225 \cdot \left(x \cdot x\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{x}{x - \tan x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -2.60000000000000009

    1. Initial program 100.0%

      \[\frac{x - \sin x}{x - \tan x} \]
    2. Step-by-step derivation
      1. sub-neg100.0%

        \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
      2. +-commutative100.0%

        \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
      3. neg-sub0100.0%

        \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
      4. associate-+l-100.0%

        \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
      5. sub0-neg100.0%

        \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
      6. neg-mul-1100.0%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
      7. sub-neg100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
      8. +-commutative100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
      9. neg-sub0100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
      10. associate-+l-100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
      11. sub0-neg100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
      12. neg-mul-1100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
      13. times-frac100.0%

        \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
      14. metadata-eval100.0%

        \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
      15. *-lft-identity100.0%

        \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    4. Taylor expanded in x around inf 98.4%

      \[\leadsto \color{blue}{1} \]

    if -2.60000000000000009 < x < 2.2999999999999998

    1. Initial program 2.1%

      \[\frac{x - \sin x}{x - \tan x} \]
    2. Step-by-step derivation
      1. sub-neg2.1%

        \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
      2. +-commutative2.1%

        \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
      3. neg-sub02.1%

        \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
      4. associate-+l-2.1%

        \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
      5. sub0-neg2.1%

        \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
      6. neg-mul-12.1%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
      7. sub-neg2.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
      8. +-commutative2.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
      9. neg-sub02.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
      10. associate-+l-2.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
      11. sub0-neg2.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
      12. neg-mul-12.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
      13. times-frac2.1%

        \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
      14. metadata-eval2.1%

        \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
      15. *-lft-identity2.1%

        \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    3. Simplified2.1%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    4. Taylor expanded in x around 0 99.7%

      \[\leadsto \color{blue}{0.225 \cdot {x}^{2} - 0.5} \]
    5. Step-by-step derivation
      1. fma-neg99.7%

        \[\leadsto \color{blue}{\mathsf{fma}\left(0.225, {x}^{2}, -0.5\right)} \]
      2. unpow299.7%

        \[\leadsto \mathsf{fma}\left(0.225, \color{blue}{x \cdot x}, -0.5\right) \]
      3. metadata-eval99.7%

        \[\leadsto \mathsf{fma}\left(0.225, x \cdot x, \color{blue}{-0.5}\right) \]
    6. Simplified99.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.225, x \cdot x, -0.5\right)} \]
    7. Step-by-step derivation
      1. fma-udef99.7%

        \[\leadsto \color{blue}{0.225 \cdot \left(x \cdot x\right) + -0.5} \]
    8. Applied egg-rr99.7%

      \[\leadsto \color{blue}{0.225 \cdot \left(x \cdot x\right) + -0.5} \]

    if 2.2999999999999998 < x

    1. Initial program 100.0%

      \[\frac{x - \sin x}{x - \tan x} \]
    2. Step-by-step derivation
      1. sub-neg100.0%

        \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
      2. +-commutative100.0%

        \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
      3. neg-sub0100.0%

        \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
      4. associate-+l-100.0%

        \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
      5. sub0-neg100.0%

        \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
      6. neg-mul-1100.0%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
      7. sub-neg100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
      8. +-commutative100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
      9. neg-sub0100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
      10. associate-+l-100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
      11. sub0-neg100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
      12. neg-mul-1100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
      13. times-frac100.0%

        \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
      14. metadata-eval100.0%

        \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
      15. *-lft-identity100.0%

        \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    4. Taylor expanded in x around inf 98.6%

      \[\leadsto \frac{\color{blue}{-1 \cdot x}}{\tan x - x} \]
    5. Step-by-step derivation
      1. neg-mul-198.6%

        \[\leadsto \frac{\color{blue}{-x}}{\tan x - x} \]
    6. Simplified98.6%

      \[\leadsto \frac{\color{blue}{-x}}{\tan x - x} \]
    7. Step-by-step derivation
      1. frac-2neg98.6%

        \[\leadsto \color{blue}{\frac{-\left(-x\right)}{-\left(\tan x - x\right)}} \]
      2. div-inv98.4%

        \[\leadsto \color{blue}{\left(-\left(-x\right)\right) \cdot \frac{1}{-\left(\tan x - x\right)}} \]
      3. remove-double-neg98.4%

        \[\leadsto \color{blue}{x} \cdot \frac{1}{-\left(\tan x - x\right)} \]
      4. sub-neg98.4%

        \[\leadsto x \cdot \frac{1}{-\color{blue}{\left(\tan x + \left(-x\right)\right)}} \]
      5. distribute-neg-in98.4%

        \[\leadsto x \cdot \frac{1}{\color{blue}{\left(-\tan x\right) + \left(-\left(-x\right)\right)}} \]
      6. remove-double-neg98.4%

        \[\leadsto x \cdot \frac{1}{\left(-\tan x\right) + \color{blue}{x}} \]
    8. Applied egg-rr98.4%

      \[\leadsto \color{blue}{x \cdot \frac{1}{\left(-\tan x\right) + x}} \]
    9. Step-by-step derivation
      1. associate-*r/98.6%

        \[\leadsto \color{blue}{\frac{x \cdot 1}{\left(-\tan x\right) + x}} \]
      2. *-rgt-identity98.6%

        \[\leadsto \frac{\color{blue}{x}}{\left(-\tan x\right) + x} \]
      3. +-commutative98.6%

        \[\leadsto \frac{x}{\color{blue}{x + \left(-\tan x\right)}} \]
      4. unsub-neg98.6%

        \[\leadsto \frac{x}{\color{blue}{x - \tan x}} \]
    10. Simplified98.6%

      \[\leadsto \color{blue}{\frac{x}{x - \tan x}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -2.6:\\ \;\;\;\;1\\ \mathbf{elif}\;x \leq 2.3:\\ \;\;\;\;-0.5 + 0.225 \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{x - \tan x}\\ \end{array} \]

Alternative 4: 98.8% accurate, 18.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -2.6:\\ \;\;\;\;1\\ \mathbf{elif}\;x \leq 2.55:\\ \;\;\;\;-0.5 + 0.225 \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -2.6) 1.0 (if (<= x 2.55) (+ -0.5 (* 0.225 (* x x))) 1.0)))
double code(double x) {
	double tmp;
	if (x <= -2.6) {
		tmp = 1.0;
	} else if (x <= 2.55) {
		tmp = -0.5 + (0.225 * (x * x));
	} else {
		tmp = 1.0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-2.6d0)) then
        tmp = 1.0d0
    else if (x <= 2.55d0) then
        tmp = (-0.5d0) + (0.225d0 * (x * x))
    else
        tmp = 1.0d0
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -2.6) {
		tmp = 1.0;
	} else if (x <= 2.55) {
		tmp = -0.5 + (0.225 * (x * x));
	} else {
		tmp = 1.0;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -2.6:
		tmp = 1.0
	elif x <= 2.55:
		tmp = -0.5 + (0.225 * (x * x))
	else:
		tmp = 1.0
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -2.6)
		tmp = 1.0;
	elseif (x <= 2.55)
		tmp = Float64(-0.5 + Float64(0.225 * Float64(x * x)));
	else
		tmp = 1.0;
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -2.6)
		tmp = 1.0;
	elseif (x <= 2.55)
		tmp = -0.5 + (0.225 * (x * x));
	else
		tmp = 1.0;
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -2.6], 1.0, If[LessEqual[x, 2.55], N[(-0.5 + N[(0.225 * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1.0]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -2.6:\\
\;\;\;\;1\\

\mathbf{elif}\;x \leq 2.55:\\
\;\;\;\;-0.5 + 0.225 \cdot \left(x \cdot x\right)\\

\mathbf{else}:\\
\;\;\;\;1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -2.60000000000000009 or 2.5499999999999998 < x

    1. Initial program 100.0%

      \[\frac{x - \sin x}{x - \tan x} \]
    2. Step-by-step derivation
      1. sub-neg100.0%

        \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
      2. +-commutative100.0%

        \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
      3. neg-sub0100.0%

        \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
      4. associate-+l-100.0%

        \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
      5. sub0-neg100.0%

        \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
      6. neg-mul-1100.0%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
      7. sub-neg100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
      8. +-commutative100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
      9. neg-sub0100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
      10. associate-+l-100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
      11. sub0-neg100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
      12. neg-mul-1100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
      13. times-frac100.0%

        \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
      14. metadata-eval100.0%

        \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
      15. *-lft-identity100.0%

        \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    4. Taylor expanded in x around inf 98.5%

      \[\leadsto \color{blue}{1} \]

    if -2.60000000000000009 < x < 2.5499999999999998

    1. Initial program 2.1%

      \[\frac{x - \sin x}{x - \tan x} \]
    2. Step-by-step derivation
      1. sub-neg2.1%

        \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
      2. +-commutative2.1%

        \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
      3. neg-sub02.1%

        \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
      4. associate-+l-2.1%

        \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
      5. sub0-neg2.1%

        \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
      6. neg-mul-12.1%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
      7. sub-neg2.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
      8. +-commutative2.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
      9. neg-sub02.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
      10. associate-+l-2.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
      11. sub0-neg2.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
      12. neg-mul-12.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
      13. times-frac2.1%

        \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
      14. metadata-eval2.1%

        \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
      15. *-lft-identity2.1%

        \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    3. Simplified2.1%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    4. Taylor expanded in x around 0 99.7%

      \[\leadsto \color{blue}{0.225 \cdot {x}^{2} - 0.5} \]
    5. Step-by-step derivation
      1. fma-neg99.7%

        \[\leadsto \color{blue}{\mathsf{fma}\left(0.225, {x}^{2}, -0.5\right)} \]
      2. unpow299.7%

        \[\leadsto \mathsf{fma}\left(0.225, \color{blue}{x \cdot x}, -0.5\right) \]
      3. metadata-eval99.7%

        \[\leadsto \mathsf{fma}\left(0.225, x \cdot x, \color{blue}{-0.5}\right) \]
    6. Simplified99.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.225, x \cdot x, -0.5\right)} \]
    7. Step-by-step derivation
      1. fma-udef99.7%

        \[\leadsto \color{blue}{0.225 \cdot \left(x \cdot x\right) + -0.5} \]
    8. Applied egg-rr99.7%

      \[\leadsto \color{blue}{0.225 \cdot \left(x \cdot x\right) + -0.5} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -2.6:\\ \;\;\;\;1\\ \mathbf{elif}\;x \leq 2.55:\\ \;\;\;\;-0.5 + 0.225 \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]

Alternative 5: 98.5% accurate, 40.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.58:\\ \;\;\;\;1\\ \mathbf{elif}\;x \leq 1.55:\\ \;\;\;\;-0.5\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.58) 1.0 (if (<= x 1.55) -0.5 1.0)))
double code(double x) {
	double tmp;
	if (x <= -1.58) {
		tmp = 1.0;
	} else if (x <= 1.55) {
		tmp = -0.5;
	} else {
		tmp = 1.0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1.58d0)) then
        tmp = 1.0d0
    else if (x <= 1.55d0) then
        tmp = -0.5d0
    else
        tmp = 1.0d0
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -1.58) {
		tmp = 1.0;
	} else if (x <= 1.55) {
		tmp = -0.5;
	} else {
		tmp = 1.0;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -1.58:
		tmp = 1.0
	elif x <= 1.55:
		tmp = -0.5
	else:
		tmp = 1.0
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -1.58)
		tmp = 1.0;
	elseif (x <= 1.55)
		tmp = -0.5;
	else
		tmp = 1.0;
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1.58)
		tmp = 1.0;
	elseif (x <= 1.55)
		tmp = -0.5;
	else
		tmp = 1.0;
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -1.58], 1.0, If[LessEqual[x, 1.55], -0.5, 1.0]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.58:\\
\;\;\;\;1\\

\mathbf{elif}\;x \leq 1.55:\\
\;\;\;\;-0.5\\

\mathbf{else}:\\
\;\;\;\;1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.5800000000000001 or 1.55000000000000004 < x

    1. Initial program 100.0%

      \[\frac{x - \sin x}{x - \tan x} \]
    2. Step-by-step derivation
      1. sub-neg100.0%

        \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
      2. +-commutative100.0%

        \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
      3. neg-sub0100.0%

        \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
      4. associate-+l-100.0%

        \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
      5. sub0-neg100.0%

        \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
      6. neg-mul-1100.0%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
      7. sub-neg100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
      8. +-commutative100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
      9. neg-sub0100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
      10. associate-+l-100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
      11. sub0-neg100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
      12. neg-mul-1100.0%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
      13. times-frac100.0%

        \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
      14. metadata-eval100.0%

        \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
      15. *-lft-identity100.0%

        \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    4. Taylor expanded in x around inf 98.5%

      \[\leadsto \color{blue}{1} \]

    if -1.5800000000000001 < x < 1.55000000000000004

    1. Initial program 2.1%

      \[\frac{x - \sin x}{x - \tan x} \]
    2. Step-by-step derivation
      1. sub-neg2.1%

        \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
      2. +-commutative2.1%

        \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
      3. neg-sub02.1%

        \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
      4. associate-+l-2.1%

        \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
      5. sub0-neg2.1%

        \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
      6. neg-mul-12.1%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
      7. sub-neg2.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
      8. +-commutative2.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
      9. neg-sub02.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
      10. associate-+l-2.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
      11. sub0-neg2.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
      12. neg-mul-12.1%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
      13. times-frac2.1%

        \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
      14. metadata-eval2.1%

        \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
      15. *-lft-identity2.1%

        \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    3. Simplified2.1%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    4. Taylor expanded in x around 0 98.5%

      \[\leadsto \color{blue}{-0.5} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.58:\\ \;\;\;\;1\\ \mathbf{elif}\;x \leq 1.55:\\ \;\;\;\;-0.5\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]

Alternative 6: 50.5% accurate, 207.0× speedup?

\[\begin{array}{l} \\ -0.5 \end{array} \]
(FPCore (x) :precision binary64 -0.5)
double code(double x) {
	return -0.5;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = -0.5d0
end function
public static double code(double x) {
	return -0.5;
}
def code(x):
	return -0.5
function code(x)
	return -0.5
end
function tmp = code(x)
	tmp = -0.5;
end
code[x_] := -0.5
\begin{array}{l}

\\
-0.5
\end{array}
Derivation
  1. Initial program 51.0%

    \[\frac{x - \sin x}{x - \tan x} \]
  2. Step-by-step derivation
    1. sub-neg51.0%

      \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
    2. +-commutative51.0%

      \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
    3. neg-sub051.0%

      \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
    4. associate-+l-51.0%

      \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
    5. sub0-neg51.0%

      \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
    6. neg-mul-151.0%

      \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
    7. sub-neg51.0%

      \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
    8. +-commutative51.0%

      \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
    9. neg-sub051.0%

      \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
    10. associate-+l-51.0%

      \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
    11. sub0-neg51.0%

      \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
    12. neg-mul-151.0%

      \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
    13. times-frac51.0%

      \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
    14. metadata-eval51.0%

      \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
    15. *-lft-identity51.0%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
  3. Simplified51.0%

    \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
  4. Taylor expanded in x around 0 50.1%

    \[\leadsto \color{blue}{-0.5} \]
  5. Final simplification50.1%

    \[\leadsto -0.5 \]

Reproduce

?
herbie shell --seed 2023178 
(FPCore (x)
  :name "sintan (problem 3.4.5)"
  :precision binary64
  (/ (- x (sin x)) (- x (tan x))))