sintan (problem 3.4.5)

Percentage Accurate: 49.6% → 99.5%
Time: 16.3s
Alternatives: 6
Speedup: 207.0×

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: 49.6% 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 99.7%

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

    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 simplification99.8%

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

Alternative 2: 99.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -2.4 \lor \neg \left(x \leq 2.4\right):\\ \;\;\;\;1 - \frac{\sin x - \tan x}{x}\\ \mathbf{else}:\\ \;\;\;\;-0.5 + 0.225 \cdot \left(x \cdot x\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (or (<= x -2.4) (not (<= x 2.4)))
   (- 1.0 (/ (- (sin x) (tan x)) x))
   (+ -0.5 (* 0.225 (* x x)))))
double code(double x) {
	double tmp;
	if ((x <= -2.4) || !(x <= 2.4)) {
		tmp = 1.0 - ((sin(x) - tan(x)) / x);
	} else {
		tmp = -0.5 + (0.225 * (x * x));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if ((x <= (-2.4d0)) .or. (.not. (x <= 2.4d0))) then
        tmp = 1.0d0 - ((sin(x) - tan(x)) / x)
    else
        tmp = (-0.5d0) + (0.225d0 * (x * x))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if ((x <= -2.4) || !(x <= 2.4)) {
		tmp = 1.0 - ((Math.sin(x) - Math.tan(x)) / x);
	} else {
		tmp = -0.5 + (0.225 * (x * x));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if (x <= -2.4) or not (x <= 2.4):
		tmp = 1.0 - ((math.sin(x) - math.tan(x)) / x)
	else:
		tmp = -0.5 + (0.225 * (x * x))
	return tmp
function code(x)
	tmp = 0.0
	if ((x <= -2.4) || !(x <= 2.4))
		tmp = Float64(1.0 - Float64(Float64(sin(x) - tan(x)) / x));
	else
		tmp = Float64(-0.5 + Float64(0.225 * Float64(x * x)));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if ((x <= -2.4) || ~((x <= 2.4)))
		tmp = 1.0 - ((sin(x) - tan(x)) / x);
	else
		tmp = -0.5 + (0.225 * (x * x));
	end
	tmp_2 = tmp;
end
code[x_] := If[Or[LessEqual[x, -2.4], N[Not[LessEqual[x, 2.4]], $MachinePrecision]], N[(1.0 - N[(N[(N[Sin[x], $MachinePrecision] - N[Tan[x], $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision], N[(-0.5 + N[(0.225 * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -2.4 \lor \neg \left(x \leq 2.4\right):\\
\;\;\;\;1 - \frac{\sin x - \tan x}{x}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -2.39999999999999991 or 2.39999999999999991 < x

    1. Initial program 99.9%

      \[\frac{x - \sin x}{x - \tan x} \]
    2. Step-by-step derivation
      1. sub-neg99.9%

        \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
      2. +-commutative99.9%

        \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
      3. neg-sub099.9%

        \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
      4. associate-+l-99.9%

        \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
      5. sub0-neg99.9%

        \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
      6. neg-mul-199.9%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
      7. sub-neg99.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
      8. +-commutative99.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
      9. neg-sub099.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
      10. associate-+l-99.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
      11. sub0-neg99.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
      12. neg-mul-199.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
      13. times-frac99.9%

        \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
      14. metadata-eval99.9%

        \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
      15. *-lft-identity99.9%

        \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    4. Taylor expanded in x around inf 98.1%

      \[\leadsto \color{blue}{\left(1 + -1 \cdot \frac{\sin x}{x}\right) - -1 \cdot \frac{\sin x}{\cos x \cdot x}} \]
    5. Step-by-step derivation
      1. associate--l+98.1%

        \[\leadsto \color{blue}{1 + \left(-1 \cdot \frac{\sin x}{x} - -1 \cdot \frac{\sin x}{\cos x \cdot x}\right)} \]
      2. associate-*r/98.1%

        \[\leadsto 1 + \left(\color{blue}{\frac{-1 \cdot \sin x}{x}} - -1 \cdot \frac{\sin x}{\cos x \cdot x}\right) \]
      3. associate-/r*98.1%

        \[\leadsto 1 + \left(\frac{-1 \cdot \sin x}{x} - -1 \cdot \color{blue}{\frac{\frac{\sin x}{\cos x}}{x}}\right) \]
      4. associate-*r/98.1%

        \[\leadsto 1 + \left(\frac{-1 \cdot \sin x}{x} - \color{blue}{\frac{-1 \cdot \frac{\sin x}{\cos x}}{x}}\right) \]
      5. div-sub98.1%

        \[\leadsto 1 + \color{blue}{\frac{-1 \cdot \sin x - -1 \cdot \frac{\sin x}{\cos x}}{x}} \]
      6. distribute-lft-out--98.1%

        \[\leadsto 1 + \frac{\color{blue}{-1 \cdot \left(\sin x - \frac{\sin x}{\cos x}\right)}}{x} \]
      7. associate-*r/98.1%

        \[\leadsto 1 + \color{blue}{-1 \cdot \frac{\sin x - \frac{\sin x}{\cos x}}{x}} \]
      8. mul-1-neg98.1%

        \[\leadsto 1 + \color{blue}{\left(-\frac{\sin x - \frac{\sin x}{\cos x}}{x}\right)} \]
      9. unsub-neg98.1%

        \[\leadsto \color{blue}{1 - \frac{\sin x - \frac{\sin x}{\cos x}}{x}} \]
    6. Simplified98.1%

      \[\leadsto \color{blue}{1 - \frac{\sin x - \frac{\sin x}{\cos x}}{x}} \]
    7. Step-by-step derivation
      1. tan-quot98.1%

        \[\leadsto 1 - \frac{\sin x - \color{blue}{\tan x}}{x} \]
      2. sub-neg98.1%

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

      \[\leadsto 1 - \frac{\color{blue}{\sin x + \left(-\tan x\right)}}{x} \]
    9. Step-by-step derivation
      1. sub-neg98.1%

        \[\leadsto 1 - \frac{\color{blue}{\sin x - \tan x}}{x} \]
    10. Simplified98.1%

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

    if -2.39999999999999991 < x < 2.39999999999999991

    1. Initial program 1.2%

      \[\frac{x - \sin x}{x - \tan x} \]
    2. Step-by-step derivation
      1. sub-neg1.2%

        \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
      2. +-commutative1.2%

        \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
      3. neg-sub01.2%

        \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
      4. associate-+l-1.2%

        \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
      5. sub0-neg1.2%

        \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
      6. neg-mul-11.2%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
      7. sub-neg1.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
      8. +-commutative1.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
      9. neg-sub01.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
      10. associate-+l-1.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
      11. sub0-neg1.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
      12. neg-mul-11.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
      13. times-frac1.2%

        \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
      14. metadata-eval1.2%

        \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
      15. *-lft-identity1.2%

        \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    3. Simplified1.2%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    4. Taylor expanded in x around 0 99.5%

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

        \[\leadsto \color{blue}{\mathsf{fma}\left(0.225, {x}^{2}, -0.5\right)} \]
      2. unpow299.5%

        \[\leadsto \mathsf{fma}\left(0.225, \color{blue}{x \cdot x}, -0.5\right) \]
      3. metadata-eval99.5%

        \[\leadsto \mathsf{fma}\left(0.225, x \cdot x, \color{blue}{-0.5}\right) \]
    6. Simplified99.5%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.225, x \cdot x, -0.5\right)} \]
    7. Step-by-step derivation
      1. fma-udef99.5%

        \[\leadsto \color{blue}{0.225 \cdot \left(x \cdot x\right) + -0.5} \]
    8. Applied egg-rr99.5%

      \[\leadsto \color{blue}{0.225 \cdot \left(x \cdot x\right) + -0.5} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -2.4 \lor \neg \left(x \leq 2.4\right):\\ \;\;\;\;1 - \frac{\sin x - \tan x}{x}\\ \mathbf{else}:\\ \;\;\;\;-0.5 + 0.225 \cdot \left(x \cdot x\right)\\ \end{array} \]

Alternative 3: 98.7% accurate, 18.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -2.6:\\ \;\;\;\;1\\ \mathbf{elif}\;x \leq 2.6:\\ \;\;\;\;-0.5 + 0.225 \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -2.6) 1.0 (if (<= x 2.6) (+ -0.5 (* 0.225 (* x x))) 1.0)))
double code(double x) {
	double tmp;
	if (x <= -2.6) {
		tmp = 1.0;
	} else if (x <= 2.6) {
		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 <= 2.6d0) 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 <= 2.6) {
		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 <= 2.6:
		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 <= 2.6)
		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 <= 2.6)
		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, 2.6], 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 2.6:\\
\;\;\;\;-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 2.60000000000000009 < x

    1. Initial program 99.9%

      \[\frac{x - \sin x}{x - \tan x} \]
    2. Step-by-step derivation
      1. sub-neg99.9%

        \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
      2. +-commutative99.9%

        \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
      3. neg-sub099.9%

        \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
      4. associate-+l-99.9%

        \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
      5. sub0-neg99.9%

        \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
      6. neg-mul-199.9%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
      7. sub-neg99.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
      8. +-commutative99.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
      9. neg-sub099.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
      10. associate-+l-99.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
      11. sub0-neg99.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
      12. neg-mul-199.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
      13. times-frac99.9%

        \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
      14. metadata-eval99.9%

        \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
      15. *-lft-identity99.9%

        \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    4. Taylor expanded in x around inf 96.5%

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

    if -2.60000000000000009 < x < 2.60000000000000009

    1. Initial program 1.2%

      \[\frac{x - \sin x}{x - \tan x} \]
    2. Step-by-step derivation
      1. sub-neg1.2%

        \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
      2. +-commutative1.2%

        \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
      3. neg-sub01.2%

        \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
      4. associate-+l-1.2%

        \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
      5. sub0-neg1.2%

        \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
      6. neg-mul-11.2%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
      7. sub-neg1.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
      8. +-commutative1.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
      9. neg-sub01.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
      10. associate-+l-1.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
      11. sub0-neg1.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
      12. neg-mul-11.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
      13. times-frac1.2%

        \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
      14. metadata-eval1.2%

        \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
      15. *-lft-identity1.2%

        \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    3. Simplified1.2%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    4. Taylor expanded in x around 0 99.5%

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

        \[\leadsto \color{blue}{\mathsf{fma}\left(0.225, {x}^{2}, -0.5\right)} \]
      2. unpow299.5%

        \[\leadsto \mathsf{fma}\left(0.225, \color{blue}{x \cdot x}, -0.5\right) \]
      3. metadata-eval99.5%

        \[\leadsto \mathsf{fma}\left(0.225, x \cdot x, \color{blue}{-0.5}\right) \]
    6. Simplified99.5%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.225, x \cdot x, -0.5\right)} \]
    7. Step-by-step derivation
      1. fma-udef99.5%

        \[\leadsto \color{blue}{0.225 \cdot \left(x \cdot x\right) + -0.5} \]
    8. Applied egg-rr99.5%

      \[\leadsto \color{blue}{0.225 \cdot \left(x \cdot x\right) + -0.5} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.1%

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

Alternative 4: 98.7% accurate, 18.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -2.9:\\ \;\;\;\;\frac{3}{x \cdot x} - -1\\ \mathbf{elif}\;x \leq 2.6:\\ \;\;\;\;-0.5 + 0.225 \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -2.9)
   (- (/ 3.0 (* x x)) -1.0)
   (if (<= x 2.6) (+ -0.5 (* 0.225 (* x x))) 1.0)))
double code(double x) {
	double tmp;
	if (x <= -2.9) {
		tmp = (3.0 / (x * x)) - -1.0;
	} else if (x <= 2.6) {
		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 <= (-2.9d0)) then
        tmp = (3.0d0 / (x * x)) - (-1.0d0)
    else if (x <= 2.6d0) 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 <= -2.9) {
		tmp = (3.0 / (x * x)) - -1.0;
	} else if (x <= 2.6) {
		tmp = -0.5 + (0.225 * (x * x));
	} else {
		tmp = 1.0;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -2.9:
		tmp = (3.0 / (x * x)) - -1.0
	elif x <= 2.6:
		tmp = -0.5 + (0.225 * (x * x))
	else:
		tmp = 1.0
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -2.9)
		tmp = Float64(Float64(3.0 / Float64(x * x)) - -1.0);
	elseif (x <= 2.6)
		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 <= -2.9)
		tmp = (3.0 / (x * x)) - -1.0;
	elseif (x <= 2.6)
		tmp = -0.5 + (0.225 * (x * x));
	else
		tmp = 1.0;
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -2.9], N[(N[(3.0 / N[(x * x), $MachinePrecision]), $MachinePrecision] - -1.0), $MachinePrecision], If[LessEqual[x, 2.6], N[(-0.5 + N[(0.225 * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1.0]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -2.9:\\
\;\;\;\;\frac{3}{x \cdot x} - -1\\

\mathbf{elif}\;x \leq 2.6:\\
\;\;\;\;-0.5 + 0.225 \cdot \left(x \cdot x\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -2.89999999999999991

    1. Initial program 99.9%

      \[\frac{x - \sin x}{x - \tan x} \]
    2. Step-by-step derivation
      1. sub-neg99.9%

        \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
      2. +-commutative99.9%

        \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
      3. neg-sub099.9%

        \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
      4. associate-+l-99.9%

        \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
      5. sub0-neg99.9%

        \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
      6. neg-mul-199.9%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
      7. sub-neg99.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
      8. +-commutative99.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
      9. neg-sub099.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
      10. associate-+l-99.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
      11. sub0-neg99.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
      12. neg-mul-199.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
      13. times-frac99.9%

        \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
      14. metadata-eval99.9%

        \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
      15. *-lft-identity99.9%

        \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    4. Step-by-step derivation
      1. div-sub99.9%

        \[\leadsto \color{blue}{\frac{\sin x}{\tan x - x} - \frac{x}{\tan x - x}} \]
    5. Applied egg-rr99.9%

      \[\leadsto \color{blue}{\frac{\sin x}{\tan x - x} - \frac{x}{\tan x - x}} \]
    6. Taylor expanded in x around 0 98.7%

      \[\leadsto \color{blue}{\frac{3}{{x}^{2}}} - \frac{x}{\tan x - x} \]
    7. Step-by-step derivation
      1. unpow298.7%

        \[\leadsto \frac{3}{\color{blue}{x \cdot x}} - \frac{x}{\tan x - x} \]
    8. Simplified98.7%

      \[\leadsto \color{blue}{\frac{3}{x \cdot x}} - \frac{x}{\tan x - x} \]
    9. Taylor expanded in x around inf 98.9%

      \[\leadsto \frac{3}{x \cdot x} - \color{blue}{-1} \]

    if -2.89999999999999991 < x < 2.60000000000000009

    1. Initial program 1.2%

      \[\frac{x - \sin x}{x - \tan x} \]
    2. Step-by-step derivation
      1. sub-neg1.2%

        \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
      2. +-commutative1.2%

        \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
      3. neg-sub01.2%

        \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
      4. associate-+l-1.2%

        \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
      5. sub0-neg1.2%

        \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
      6. neg-mul-11.2%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
      7. sub-neg1.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
      8. +-commutative1.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
      9. neg-sub01.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
      10. associate-+l-1.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
      11. sub0-neg1.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
      12. neg-mul-11.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
      13. times-frac1.2%

        \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
      14. metadata-eval1.2%

        \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
      15. *-lft-identity1.2%

        \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    3. Simplified1.2%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    4. Taylor expanded in x around 0 99.5%

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

        \[\leadsto \color{blue}{\mathsf{fma}\left(0.225, {x}^{2}, -0.5\right)} \]
      2. unpow299.5%

        \[\leadsto \mathsf{fma}\left(0.225, \color{blue}{x \cdot x}, -0.5\right) \]
      3. metadata-eval99.5%

        \[\leadsto \mathsf{fma}\left(0.225, x \cdot x, \color{blue}{-0.5}\right) \]
    6. Simplified99.5%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.225, x \cdot x, -0.5\right)} \]
    7. Step-by-step derivation
      1. fma-udef99.5%

        \[\leadsto \color{blue}{0.225 \cdot \left(x \cdot x\right) + -0.5} \]
    8. Applied egg-rr99.5%

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

    if 2.60000000000000009 < 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 94.6%

      \[\leadsto \color{blue}{1} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification98.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -2.9:\\ \;\;\;\;\frac{3}{x \cdot x} - -1\\ \mathbf{elif}\;x \leq 2.6:\\ \;\;\;\;-0.5 + 0.225 \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]

Alternative 5: 98.4% accurate, 40.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.55:\\ \;\;\;\;1\\ \mathbf{elif}\;x \leq 1.56:\\ \;\;\;\;-0.5\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.55) 1.0 (if (<= x 1.56) -0.5 1.0)))
double code(double x) {
	double tmp;
	if (x <= -1.55) {
		tmp = 1.0;
	} else if (x <= 1.56) {
		tmp = -0.5;
	} else {
		tmp = 1.0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1.55d0)) then
        tmp = 1.0d0
    else if (x <= 1.56d0) then
        tmp = -0.5d0
    else
        tmp = 1.0d0
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -1.55) {
		tmp = 1.0;
	} else if (x <= 1.56) {
		tmp = -0.5;
	} else {
		tmp = 1.0;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -1.55:
		tmp = 1.0
	elif x <= 1.56:
		tmp = -0.5
	else:
		tmp = 1.0
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -1.55)
		tmp = 1.0;
	elseif (x <= 1.56)
		tmp = -0.5;
	else
		tmp = 1.0;
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1.55)
		tmp = 1.0;
	elseif (x <= 1.56)
		tmp = -0.5;
	else
		tmp = 1.0;
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -1.55], 1.0, If[LessEqual[x, 1.56], -0.5, 1.0]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.55:\\
\;\;\;\;1\\

\mathbf{elif}\;x \leq 1.56:\\
\;\;\;\;-0.5\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.55000000000000004 or 1.5600000000000001 < x

    1. Initial program 99.9%

      \[\frac{x - \sin x}{x - \tan x} \]
    2. Step-by-step derivation
      1. sub-neg99.9%

        \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
      2. +-commutative99.9%

        \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
      3. neg-sub099.9%

        \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
      4. associate-+l-99.9%

        \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
      5. sub0-neg99.9%

        \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
      6. neg-mul-199.9%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
      7. sub-neg99.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
      8. +-commutative99.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
      9. neg-sub099.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
      10. associate-+l-99.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
      11. sub0-neg99.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
      12. neg-mul-199.9%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
      13. times-frac99.9%

        \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
      14. metadata-eval99.9%

        \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
      15. *-lft-identity99.9%

        \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    4. Taylor expanded in x around inf 96.5%

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

    if -1.55000000000000004 < x < 1.5600000000000001

    1. Initial program 1.2%

      \[\frac{x - \sin x}{x - \tan x} \]
    2. Step-by-step derivation
      1. sub-neg1.2%

        \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
      2. +-commutative1.2%

        \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
      3. neg-sub01.2%

        \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
      4. associate-+l-1.2%

        \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
      5. sub0-neg1.2%

        \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
      6. neg-mul-11.2%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
      7. sub-neg1.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
      8. +-commutative1.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
      9. neg-sub01.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
      10. associate-+l-1.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
      11. sub0-neg1.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
      12. neg-mul-11.2%

        \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
      13. times-frac1.2%

        \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
      14. metadata-eval1.2%

        \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
      15. *-lft-identity1.2%

        \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    3. Simplified1.2%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
    4. Taylor expanded in x around 0 99.2%

      \[\leadsto \color{blue}{-0.5} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification97.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.55:\\ \;\;\;\;1\\ \mathbf{elif}\;x \leq 1.56:\\ \;\;\;\;-0.5\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]

Alternative 6: 51.6% 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 48.7%

    \[\frac{x - \sin x}{x - \tan x} \]
  2. Step-by-step derivation
    1. sub-neg48.7%

      \[\leadsto \frac{\color{blue}{x + \left(-\sin x\right)}}{x - \tan x} \]
    2. +-commutative48.7%

      \[\leadsto \frac{\color{blue}{\left(-\sin x\right) + x}}{x - \tan x} \]
    3. neg-sub048.7%

      \[\leadsto \frac{\color{blue}{\left(0 - \sin x\right)} + x}{x - \tan x} \]
    4. associate-+l-48.7%

      \[\leadsto \frac{\color{blue}{0 - \left(\sin x - x\right)}}{x - \tan x} \]
    5. sub0-neg48.7%

      \[\leadsto \frac{\color{blue}{-\left(\sin x - x\right)}}{x - \tan x} \]
    6. neg-mul-148.7%

      \[\leadsto \frac{\color{blue}{-1 \cdot \left(\sin x - x\right)}}{x - \tan x} \]
    7. sub-neg48.7%

      \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{x + \left(-\tan x\right)}} \]
    8. +-commutative48.7%

      \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(-\tan x\right) + x}} \]
    9. neg-sub048.7%

      \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{\left(0 - \tan x\right)} + x} \]
    10. associate-+l-48.7%

      \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{0 - \left(\tan x - x\right)}} \]
    11. sub0-neg48.7%

      \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-\left(\tan x - x\right)}} \]
    12. neg-mul-148.7%

      \[\leadsto \frac{-1 \cdot \left(\sin x - x\right)}{\color{blue}{-1 \cdot \left(\tan x - x\right)}} \]
    13. times-frac48.7%

      \[\leadsto \color{blue}{\frac{-1}{-1} \cdot \frac{\sin x - x}{\tan x - x}} \]
    14. metadata-eval48.7%

      \[\leadsto \color{blue}{1} \cdot \frac{\sin x - x}{\tan x - x} \]
    15. *-lft-identity48.7%

      \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
  3. Simplified48.7%

    \[\leadsto \color{blue}{\frac{\sin x - x}{\tan x - x}} \]
  4. Taylor expanded in x around 0 52.3%

    \[\leadsto \color{blue}{-0.5} \]
  5. Final simplification52.3%

    \[\leadsto -0.5 \]

Reproduce

?
herbie shell --seed 2023187 
(FPCore (x)
  :name "sintan (problem 3.4.5)"
  :precision binary64
  (/ (- x (sin x)) (- x (tan x))))