Kahan p13 Example 3

Percentage Accurate: 100.0% → 100.0%
Time: 7.7s
Alternatives: 10
Speedup: N/A×

Specification

?
\[\begin{array}{l} \\ \begin{array}{l} t_1 := 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\\ 1 - \frac{1}{2 + t\_1 \cdot t\_1} \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (- 2.0 (/ (/ 2.0 t) (+ 1.0 (/ 1.0 t))))))
   (- 1.0 (/ 1.0 (+ 2.0 (* t_1 t_1))))))
double code(double t) {
	double t_1 = 2.0 - ((2.0 / t) / (1.0 + (1.0 / t)));
	return 1.0 - (1.0 / (2.0 + (t_1 * t_1)));
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    t_1 = 2.0d0 - ((2.0d0 / t) / (1.0d0 + (1.0d0 / t)))
    code = 1.0d0 - (1.0d0 / (2.0d0 + (t_1 * t_1)))
end function
public static double code(double t) {
	double t_1 = 2.0 - ((2.0 / t) / (1.0 + (1.0 / t)));
	return 1.0 - (1.0 / (2.0 + (t_1 * t_1)));
}
def code(t):
	t_1 = 2.0 - ((2.0 / t) / (1.0 + (1.0 / t)))
	return 1.0 - (1.0 / (2.0 + (t_1 * t_1)))
function code(t)
	t_1 = Float64(2.0 - Float64(Float64(2.0 / t) / Float64(1.0 + Float64(1.0 / t))))
	return Float64(1.0 - Float64(1.0 / Float64(2.0 + Float64(t_1 * t_1))))
end
function tmp = code(t)
	t_1 = 2.0 - ((2.0 / t) / (1.0 + (1.0 / t)));
	tmp = 1.0 - (1.0 / (2.0 + (t_1 * t_1)));
end
code[t_] := Block[{t$95$1 = N[(2.0 - N[(N[(2.0 / t), $MachinePrecision] / N[(1.0 + N[(1.0 / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(1.0 - N[(1.0 / N[(2.0 + N[(t$95$1 * t$95$1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\\
1 - \frac{1}{2 + t\_1 \cdot t\_1}
\end{array}
\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 10 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: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\\ 1 - \frac{1}{2 + t\_1 \cdot t\_1} \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (- 2.0 (/ (/ 2.0 t) (+ 1.0 (/ 1.0 t))))))
   (- 1.0 (/ 1.0 (+ 2.0 (* t_1 t_1))))))
double code(double t) {
	double t_1 = 2.0 - ((2.0 / t) / (1.0 + (1.0 / t)));
	return 1.0 - (1.0 / (2.0 + (t_1 * t_1)));
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    t_1 = 2.0d0 - ((2.0d0 / t) / (1.0d0 + (1.0d0 / t)))
    code = 1.0d0 - (1.0d0 / (2.0d0 + (t_1 * t_1)))
end function
public static double code(double t) {
	double t_1 = 2.0 - ((2.0 / t) / (1.0 + (1.0 / t)));
	return 1.0 - (1.0 / (2.0 + (t_1 * t_1)));
}
def code(t):
	t_1 = 2.0 - ((2.0 / t) / (1.0 + (1.0 / t)))
	return 1.0 - (1.0 / (2.0 + (t_1 * t_1)))
function code(t)
	t_1 = Float64(2.0 - Float64(Float64(2.0 / t) / Float64(1.0 + Float64(1.0 / t))))
	return Float64(1.0 - Float64(1.0 / Float64(2.0 + Float64(t_1 * t_1))))
end
function tmp = code(t)
	t_1 = 2.0 - ((2.0 / t) / (1.0 + (1.0 / t)));
	tmp = 1.0 - (1.0 / (2.0 + (t_1 * t_1)));
end
code[t_] := Block[{t$95$1 = N[(2.0 - N[(N[(2.0 / t), $MachinePrecision] / N[(1.0 + N[(1.0 / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(1.0 - N[(1.0 / N[(2.0 + N[(t$95$1 * t$95$1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\\
1 - \frac{1}{2 + t\_1 \cdot t\_1}
\end{array}
\end{array}

Alternative 1: 100.0% accurate, 1.5× speedup?

\[\begin{array}{l} \\ 1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)} \end{array} \]
(FPCore (t)
 :precision binary64
 (+ 1.0 (/ 1.0 (+ -6.0 (* (/ 2.0 (+ 1.0 t)) (+ (/ 2.0 (- -1.0 t)) 4.0))))))
double code(double t) {
	return 1.0 + (1.0 / (-6.0 + ((2.0 / (1.0 + t)) * ((2.0 / (-1.0 - t)) + 4.0))));
}
real(8) function code(t)
    real(8), intent (in) :: t
    code = 1.0d0 + (1.0d0 / ((-6.0d0) + ((2.0d0 / (1.0d0 + t)) * ((2.0d0 / ((-1.0d0) - t)) + 4.0d0))))
end function
public static double code(double t) {
	return 1.0 + (1.0 / (-6.0 + ((2.0 / (1.0 + t)) * ((2.0 / (-1.0 - t)) + 4.0))));
}
def code(t):
	return 1.0 + (1.0 / (-6.0 + ((2.0 / (1.0 + t)) * ((2.0 / (-1.0 - t)) + 4.0))))
function code(t)
	return Float64(1.0 + Float64(1.0 / Float64(-6.0 + Float64(Float64(2.0 / Float64(1.0 + t)) * Float64(Float64(2.0 / Float64(-1.0 - t)) + 4.0)))))
end
function tmp = code(t)
	tmp = 1.0 + (1.0 / (-6.0 + ((2.0 / (1.0 + t)) * ((2.0 / (-1.0 - t)) + 4.0))));
end
code[t_] := N[(1.0 + N[(1.0 / N[(-6.0 + N[(N[(2.0 / N[(1.0 + t), $MachinePrecision]), $MachinePrecision] * N[(N[(2.0 / N[(-1.0 - t), $MachinePrecision]), $MachinePrecision] + 4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}
\end{array}
Derivation
  1. Initial program 100.0%

    \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
  2. Simplified100.0%

    \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
  3. Add Preprocessing
  4. Add Preprocessing

Alternative 2: 99.7% accurate, 1.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := 0.8333333333333334 - \frac{0.2222222222222222 + \frac{-0.037037037037037035 + \frac{-0.04938271604938271}{t}}{t}}{t}\\ \mathbf{if}\;t \leq -0.35:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;t \leq 0.72:\\ \;\;\;\;0.5 + \left(t \cdot t\right) \cdot \left(1 + t \cdot \left(t + -2\right)\right)\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1
         (-
          0.8333333333333334
          (/
           (+
            0.2222222222222222
            (/ (+ -0.037037037037037035 (/ -0.04938271604938271 t)) t))
           t))))
   (if (<= t -0.35)
     t_1
     (if (<= t 0.72) (+ 0.5 (* (* t t) (+ 1.0 (* t (+ t -2.0))))) t_1))))
double code(double t) {
	double t_1 = 0.8333333333333334 - ((0.2222222222222222 + ((-0.037037037037037035 + (-0.04938271604938271 / t)) / t)) / t);
	double tmp;
	if (t <= -0.35) {
		tmp = t_1;
	} else if (t <= 0.72) {
		tmp = 0.5 + ((t * t) * (1.0 + (t * (t + -2.0))));
	} else {
		tmp = t_1;
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: tmp
    t_1 = 0.8333333333333334d0 - ((0.2222222222222222d0 + (((-0.037037037037037035d0) + ((-0.04938271604938271d0) / t)) / t)) / t)
    if (t <= (-0.35d0)) then
        tmp = t_1
    else if (t <= 0.72d0) then
        tmp = 0.5d0 + ((t * t) * (1.0d0 + (t * (t + (-2.0d0)))))
    else
        tmp = t_1
    end if
    code = tmp
end function
public static double code(double t) {
	double t_1 = 0.8333333333333334 - ((0.2222222222222222 + ((-0.037037037037037035 + (-0.04938271604938271 / t)) / t)) / t);
	double tmp;
	if (t <= -0.35) {
		tmp = t_1;
	} else if (t <= 0.72) {
		tmp = 0.5 + ((t * t) * (1.0 + (t * (t + -2.0))));
	} else {
		tmp = t_1;
	}
	return tmp;
}
def code(t):
	t_1 = 0.8333333333333334 - ((0.2222222222222222 + ((-0.037037037037037035 + (-0.04938271604938271 / t)) / t)) / t)
	tmp = 0
	if t <= -0.35:
		tmp = t_1
	elif t <= 0.72:
		tmp = 0.5 + ((t * t) * (1.0 + (t * (t + -2.0))))
	else:
		tmp = t_1
	return tmp
function code(t)
	t_1 = Float64(0.8333333333333334 - Float64(Float64(0.2222222222222222 + Float64(Float64(-0.037037037037037035 + Float64(-0.04938271604938271 / t)) / t)) / t))
	tmp = 0.0
	if (t <= -0.35)
		tmp = t_1;
	elseif (t <= 0.72)
		tmp = Float64(0.5 + Float64(Float64(t * t) * Float64(1.0 + Float64(t * Float64(t + -2.0)))));
	else
		tmp = t_1;
	end
	return tmp
end
function tmp_2 = code(t)
	t_1 = 0.8333333333333334 - ((0.2222222222222222 + ((-0.037037037037037035 + (-0.04938271604938271 / t)) / t)) / t);
	tmp = 0.0;
	if (t <= -0.35)
		tmp = t_1;
	elseif (t <= 0.72)
		tmp = 0.5 + ((t * t) * (1.0 + (t * (t + -2.0))));
	else
		tmp = t_1;
	end
	tmp_2 = tmp;
end
code[t_] := Block[{t$95$1 = N[(0.8333333333333334 - N[(N[(0.2222222222222222 + N[(N[(-0.037037037037037035 + N[(-0.04938271604938271 / t), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t, -0.35], t$95$1, If[LessEqual[t, 0.72], N[(0.5 + N[(N[(t * t), $MachinePrecision] * N[(1.0 + N[(t * N[(t + -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$1]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := 0.8333333333333334 - \frac{0.2222222222222222 + \frac{-0.037037037037037035 + \frac{-0.04938271604938271}{t}}{t}}{t}\\
\mathbf{if}\;t \leq -0.35:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;t \leq 0.72:\\
\;\;\;\;0.5 + \left(t \cdot t\right) \cdot \left(1 + t \cdot \left(t + -2\right)\right)\\

\mathbf{else}:\\
\;\;\;\;t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < -0.34999999999999998 or 0.71999999999999997 < t

    1. Initial program 100.0%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around -inf

      \[\leadsto \color{blue}{\frac{5}{6} + -1 \cdot \frac{\frac{2}{9} + -1 \cdot \frac{\frac{1}{27} + \frac{4}{81} \cdot \frac{1}{t}}{t}}{t}} \]
    5. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \frac{5}{6} + \left(\mathsf{neg}\left(\frac{\frac{2}{9} + -1 \cdot \frac{\frac{1}{27} + \frac{4}{81} \cdot \frac{1}{t}}{t}}{t}\right)\right) \]
      2. unsub-negN/A

        \[\leadsto \frac{5}{6} - \color{blue}{\frac{\frac{2}{9} + -1 \cdot \frac{\frac{1}{27} + \frac{4}{81} \cdot \frac{1}{t}}{t}}{t}} \]
      3. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\frac{5}{6}, \color{blue}{\left(\frac{\frac{2}{9} + -1 \cdot \frac{\frac{1}{27} + \frac{4}{81} \cdot \frac{1}{t}}{t}}{t}\right)}\right) \]
      4. /-lowering-/.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\frac{5}{6}, \mathsf{/.f64}\left(\left(\frac{2}{9} + -1 \cdot \frac{\frac{1}{27} + \frac{4}{81} \cdot \frac{1}{t}}{t}\right), \color{blue}{t}\right)\right) \]
    6. Simplified99.9%

      \[\leadsto \color{blue}{0.8333333333333334 - \frac{0.2222222222222222 + \frac{-0.037037037037037035 + \frac{-0.04938271604938271}{t}}{t}}{t}} \]

    if -0.34999999999999998 < t < 0.71999999999999997

    1. Initial program 100.0%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around 0

      \[\leadsto \color{blue}{\frac{1}{2} + {t}^{2} \cdot \left(1 + t \cdot \left(t - 2\right)\right)} \]
    5. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \color{blue}{\left({t}^{2} \cdot \left(1 + t \cdot \left(t - 2\right)\right)\right)}\right) \]
      2. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left({t}^{2}\right), \color{blue}{\left(1 + t \cdot \left(t - 2\right)\right)}\right)\right) \]
      3. unpow2N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left(t \cdot t\right), \left(\color{blue}{1} + t \cdot \left(t - 2\right)\right)\right)\right) \]
      4. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(t, t\right), \left(\color{blue}{1} + t \cdot \left(t - 2\right)\right)\right)\right) \]
      5. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(t, t\right), \mathsf{+.f64}\left(1, \color{blue}{\left(t \cdot \left(t - 2\right)\right)}\right)\right)\right) \]
      6. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(t, t\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(t, \color{blue}{\left(t - 2\right)}\right)\right)\right)\right) \]
      7. sub-negN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(t, t\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(t, \left(t + \color{blue}{\left(\mathsf{neg}\left(2\right)\right)}\right)\right)\right)\right)\right) \]
      8. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(t, t\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(t, \left(t + -2\right)\right)\right)\right)\right) \]
      9. +-lowering-+.f6499.4%

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(t, t\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(t, \mathsf{+.f64}\left(t, \color{blue}{-2}\right)\right)\right)\right)\right) \]
    6. Simplified99.4%

      \[\leadsto \color{blue}{0.5 + \left(t \cdot t\right) \cdot \left(1 + t \cdot \left(t + -2\right)\right)} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 3: 99.6% accurate, 1.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{\frac{0.037037037037037035}{t} + -0.2222222222222222}{t}\\ \mathbf{if}\;t \leq -0.58:\\ \;\;\;\;1 + \left(-0.16666666666666666 + t\_1\right)\\ \mathbf{elif}\;t \leq 0.6:\\ \;\;\;\;0.5 + \left(t \cdot t\right) \cdot \left(1 + t \cdot \left(t + -2\right)\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 + t\_1\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (/ (+ (/ 0.037037037037037035 t) -0.2222222222222222) t)))
   (if (<= t -0.58)
     (+ 1.0 (+ -0.16666666666666666 t_1))
     (if (<= t 0.6)
       (+ 0.5 (* (* t t) (+ 1.0 (* t (+ t -2.0)))))
       (+ 0.8333333333333334 t_1)))))
double code(double t) {
	double t_1 = ((0.037037037037037035 / t) + -0.2222222222222222) / t;
	double tmp;
	if (t <= -0.58) {
		tmp = 1.0 + (-0.16666666666666666 + t_1);
	} else if (t <= 0.6) {
		tmp = 0.5 + ((t * t) * (1.0 + (t * (t + -2.0))));
	} else {
		tmp = 0.8333333333333334 + t_1;
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: tmp
    t_1 = ((0.037037037037037035d0 / t) + (-0.2222222222222222d0)) / t
    if (t <= (-0.58d0)) then
        tmp = 1.0d0 + ((-0.16666666666666666d0) + t_1)
    else if (t <= 0.6d0) then
        tmp = 0.5d0 + ((t * t) * (1.0d0 + (t * (t + (-2.0d0)))))
    else
        tmp = 0.8333333333333334d0 + t_1
    end if
    code = tmp
end function
public static double code(double t) {
	double t_1 = ((0.037037037037037035 / t) + -0.2222222222222222) / t;
	double tmp;
	if (t <= -0.58) {
		tmp = 1.0 + (-0.16666666666666666 + t_1);
	} else if (t <= 0.6) {
		tmp = 0.5 + ((t * t) * (1.0 + (t * (t + -2.0))));
	} else {
		tmp = 0.8333333333333334 + t_1;
	}
	return tmp;
}
def code(t):
	t_1 = ((0.037037037037037035 / t) + -0.2222222222222222) / t
	tmp = 0
	if t <= -0.58:
		tmp = 1.0 + (-0.16666666666666666 + t_1)
	elif t <= 0.6:
		tmp = 0.5 + ((t * t) * (1.0 + (t * (t + -2.0))))
	else:
		tmp = 0.8333333333333334 + t_1
	return tmp
function code(t)
	t_1 = Float64(Float64(Float64(0.037037037037037035 / t) + -0.2222222222222222) / t)
	tmp = 0.0
	if (t <= -0.58)
		tmp = Float64(1.0 + Float64(-0.16666666666666666 + t_1));
	elseif (t <= 0.6)
		tmp = Float64(0.5 + Float64(Float64(t * t) * Float64(1.0 + Float64(t * Float64(t + -2.0)))));
	else
		tmp = Float64(0.8333333333333334 + t_1);
	end
	return tmp
end
function tmp_2 = code(t)
	t_1 = ((0.037037037037037035 / t) + -0.2222222222222222) / t;
	tmp = 0.0;
	if (t <= -0.58)
		tmp = 1.0 + (-0.16666666666666666 + t_1);
	elseif (t <= 0.6)
		tmp = 0.5 + ((t * t) * (1.0 + (t * (t + -2.0))));
	else
		tmp = 0.8333333333333334 + t_1;
	end
	tmp_2 = tmp;
end
code[t_] := Block[{t$95$1 = N[(N[(N[(0.037037037037037035 / t), $MachinePrecision] + -0.2222222222222222), $MachinePrecision] / t), $MachinePrecision]}, If[LessEqual[t, -0.58], N[(1.0 + N[(-0.16666666666666666 + t$95$1), $MachinePrecision]), $MachinePrecision], If[LessEqual[t, 0.6], N[(0.5 + N[(N[(t * t), $MachinePrecision] * N[(1.0 + N[(t * N[(t + -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(0.8333333333333334 + t$95$1), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{\frac{0.037037037037037035}{t} + -0.2222222222222222}{t}\\
\mathbf{if}\;t \leq -0.58:\\
\;\;\;\;1 + \left(-0.16666666666666666 + t\_1\right)\\

\mathbf{elif}\;t \leq 0.6:\\
\;\;\;\;0.5 + \left(t \cdot t\right) \cdot \left(1 + t \cdot \left(t + -2\right)\right)\\

\mathbf{else}:\\
\;\;\;\;0.8333333333333334 + t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if t < -0.57999999999999996

    1. Initial program 100.0%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around inf

      \[\leadsto \mathsf{+.f64}\left(1, \color{blue}{\left(\frac{\frac{1}{27}}{{t}^{2}} - \left(\frac{1}{6} + \frac{2}{9} \cdot \frac{1}{t}\right)\right)}\right) \]
    5. Step-by-step derivation
      1. associate--r+N/A

        \[\leadsto \mathsf{+.f64}\left(1, \left(\left(\frac{\frac{1}{27}}{{t}^{2}} - \frac{1}{6}\right) - \color{blue}{\frac{2}{9} \cdot \frac{1}{t}}\right)\right) \]
      2. sub-negN/A

        \[\leadsto \mathsf{+.f64}\left(1, \left(\left(\frac{\frac{1}{27}}{{t}^{2}} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right)\right) - \color{blue}{\frac{2}{9}} \cdot \frac{1}{t}\right)\right) \]
      3. +-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(1, \left(\left(\left(\mathsf{neg}\left(\frac{1}{6}\right)\right) + \frac{\frac{1}{27}}{{t}^{2}}\right) - \color{blue}{\frac{2}{9}} \cdot \frac{1}{t}\right)\right) \]
      4. associate-+r-N/A

        \[\leadsto \mathsf{+.f64}\left(1, \left(\left(\mathsf{neg}\left(\frac{1}{6}\right)\right) + \color{blue}{\left(\frac{\frac{1}{27}}{{t}^{2}} - \frac{2}{9} \cdot \frac{1}{t}\right)}\right)\right) \]
      5. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\left(\mathsf{neg}\left(\frac{1}{6}\right)\right), \color{blue}{\left(\frac{\frac{1}{27}}{{t}^{2}} - \frac{2}{9} \cdot \frac{1}{t}\right)}\right)\right) \]
      6. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(\color{blue}{\frac{\frac{1}{27}}{{t}^{2}}} - \frac{2}{9} \cdot \frac{1}{t}\right)\right)\right) \]
      7. sub-negN/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(\frac{\frac{1}{27}}{{t}^{2}} + \color{blue}{\left(\mathsf{neg}\left(\frac{2}{9} \cdot \frac{1}{t}\right)\right)}\right)\right)\right) \]
      8. +-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(\left(\mathsf{neg}\left(\frac{2}{9} \cdot \frac{1}{t}\right)\right) + \color{blue}{\frac{\frac{1}{27}}{{t}^{2}}}\right)\right)\right) \]
      9. neg-sub0N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(\left(0 - \frac{2}{9} \cdot \frac{1}{t}\right) + \frac{\color{blue}{\frac{1}{27}}}{{t}^{2}}\right)\right)\right) \]
      10. associate--r-N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(0 - \color{blue}{\left(\frac{2}{9} \cdot \frac{1}{t} - \frac{\frac{1}{27}}{{t}^{2}}\right)}\right)\right)\right) \]
      11. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(0 - \left(\frac{\frac{2}{9} \cdot 1}{t} - \frac{\color{blue}{\frac{1}{27}}}{{t}^{2}}\right)\right)\right)\right) \]
      12. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27}}{{t}^{2}}\right)\right)\right)\right) \]
      13. unpow2N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27}}{t \cdot \color{blue}{t}}\right)\right)\right)\right) \]
      14. associate-/r*N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{\frac{1}{27}}{t}}{\color{blue}{t}}\right)\right)\right)\right) \]
      15. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{\frac{1}{27} \cdot 1}{t}}{t}\right)\right)\right)\right) \]
      16. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27} \cdot \frac{1}{t}}{t}\right)\right)\right)\right) \]
      17. div-subN/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(0 - \frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{\color{blue}{t}}\right)\right)\right) \]
      18. neg-sub0N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(\mathsf{neg}\left(\frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{t}\right)\right)\right)\right) \]
      19. distribute-neg-fracN/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(\frac{\mathsf{neg}\left(\left(\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}\right)\right)}{\color{blue}{t}}\right)\right)\right) \]
      20. mul-1-negN/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(\frac{-1 \cdot \left(\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}\right)}{t}\right)\right)\right) \]
    6. Simplified99.7%

      \[\leadsto 1 + \color{blue}{\left(-0.16666666666666666 + \frac{\frac{0.037037037037037035}{t} + -0.2222222222222222}{t}\right)} \]

    if -0.57999999999999996 < t < 0.599999999999999978

    1. Initial program 100.0%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around 0

      \[\leadsto \color{blue}{\frac{1}{2} + {t}^{2} \cdot \left(1 + t \cdot \left(t - 2\right)\right)} \]
    5. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \color{blue}{\left({t}^{2} \cdot \left(1 + t \cdot \left(t - 2\right)\right)\right)}\right) \]
      2. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left({t}^{2}\right), \color{blue}{\left(1 + t \cdot \left(t - 2\right)\right)}\right)\right) \]
      3. unpow2N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left(t \cdot t\right), \left(\color{blue}{1} + t \cdot \left(t - 2\right)\right)\right)\right) \]
      4. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(t, t\right), \left(\color{blue}{1} + t \cdot \left(t - 2\right)\right)\right)\right) \]
      5. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(t, t\right), \mathsf{+.f64}\left(1, \color{blue}{\left(t \cdot \left(t - 2\right)\right)}\right)\right)\right) \]
      6. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(t, t\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(t, \color{blue}{\left(t - 2\right)}\right)\right)\right)\right) \]
      7. sub-negN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(t, t\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(t, \left(t + \color{blue}{\left(\mathsf{neg}\left(2\right)\right)}\right)\right)\right)\right)\right) \]
      8. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(t, t\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(t, \left(t + -2\right)\right)\right)\right)\right) \]
      9. +-lowering-+.f6499.4%

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(t, t\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(t, \mathsf{+.f64}\left(t, \color{blue}{-2}\right)\right)\right)\right)\right) \]
    6. Simplified99.4%

      \[\leadsto \color{blue}{0.5 + \left(t \cdot t\right) \cdot \left(1 + t \cdot \left(t + -2\right)\right)} \]

    if 0.599999999999999978 < t

    1. Initial program 100.0%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around inf

      \[\leadsto \color{blue}{\left(\frac{5}{6} + \frac{\frac{1}{27}}{{t}^{2}}\right) - \frac{2}{9} \cdot \frac{1}{t}} \]
    5. Step-by-step derivation
      1. associate--l+N/A

        \[\leadsto \frac{5}{6} + \color{blue}{\left(\frac{\frac{1}{27}}{{t}^{2}} - \frac{2}{9} \cdot \frac{1}{t}\right)} \]
      2. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \color{blue}{\left(\frac{\frac{1}{27}}{{t}^{2}} - \frac{2}{9} \cdot \frac{1}{t}\right)}\right) \]
      3. sub-negN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\frac{\frac{1}{27}}{{t}^{2}} + \color{blue}{\left(\mathsf{neg}\left(\frac{2}{9} \cdot \frac{1}{t}\right)\right)}\right)\right) \]
      4. +-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\left(\mathsf{neg}\left(\frac{2}{9} \cdot \frac{1}{t}\right)\right) + \color{blue}{\frac{\frac{1}{27}}{{t}^{2}}}\right)\right) \]
      5. neg-sub0N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\left(0 - \frac{2}{9} \cdot \frac{1}{t}\right) + \frac{\color{blue}{\frac{1}{27}}}{{t}^{2}}\right)\right) \]
      6. associate--r-N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \color{blue}{\left(\frac{2}{9} \cdot \frac{1}{t} - \frac{\frac{1}{27}}{{t}^{2}}\right)}\right)\right) \]
      7. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9} \cdot 1}{t} - \frac{\color{blue}{\frac{1}{27}}}{{t}^{2}}\right)\right)\right) \]
      8. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27}}{{t}^{2}}\right)\right)\right) \]
      9. unpow2N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27}}{t \cdot \color{blue}{t}}\right)\right)\right) \]
      10. associate-/r*N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{\frac{1}{27}}{t}}{\color{blue}{t}}\right)\right)\right) \]
      11. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{\frac{1}{27} \cdot 1}{t}}{t}\right)\right)\right) \]
      12. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27} \cdot \frac{1}{t}}{t}\right)\right)\right) \]
      13. div-subN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{\color{blue}{t}}\right)\right) \]
      14. neg-sub0N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\mathsf{neg}\left(\frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{t}\right)\right)\right) \]
      15. distribute-neg-fracN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\frac{\mathsf{neg}\left(\left(\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}\right)\right)}{\color{blue}{t}}\right)\right) \]
      16. mul-1-negN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\frac{-1 \cdot \left(\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}\right)}{t}\right)\right) \]
    6. Simplified99.7%

      \[\leadsto \color{blue}{0.8333333333333334 + \frac{\frac{0.037037037037037035}{t} + -0.2222222222222222}{t}} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 4: 99.6% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{\frac{0.037037037037037035}{t} + -0.2222222222222222}{t}\\ \mathbf{if}\;t \leq -0.6:\\ \;\;\;\;1 + \left(-0.16666666666666666 + t\_1\right)\\ \mathbf{elif}\;t \leq 0.45:\\ \;\;\;\;0.5 + t \cdot \left(t \cdot \left(1 + t \cdot -2\right)\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 + t\_1\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (/ (+ (/ 0.037037037037037035 t) -0.2222222222222222) t)))
   (if (<= t -0.6)
     (+ 1.0 (+ -0.16666666666666666 t_1))
     (if (<= t 0.45)
       (+ 0.5 (* t (* t (+ 1.0 (* t -2.0)))))
       (+ 0.8333333333333334 t_1)))))
double code(double t) {
	double t_1 = ((0.037037037037037035 / t) + -0.2222222222222222) / t;
	double tmp;
	if (t <= -0.6) {
		tmp = 1.0 + (-0.16666666666666666 + t_1);
	} else if (t <= 0.45) {
		tmp = 0.5 + (t * (t * (1.0 + (t * -2.0))));
	} else {
		tmp = 0.8333333333333334 + t_1;
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: tmp
    t_1 = ((0.037037037037037035d0 / t) + (-0.2222222222222222d0)) / t
    if (t <= (-0.6d0)) then
        tmp = 1.0d0 + ((-0.16666666666666666d0) + t_1)
    else if (t <= 0.45d0) then
        tmp = 0.5d0 + (t * (t * (1.0d0 + (t * (-2.0d0)))))
    else
        tmp = 0.8333333333333334d0 + t_1
    end if
    code = tmp
end function
public static double code(double t) {
	double t_1 = ((0.037037037037037035 / t) + -0.2222222222222222) / t;
	double tmp;
	if (t <= -0.6) {
		tmp = 1.0 + (-0.16666666666666666 + t_1);
	} else if (t <= 0.45) {
		tmp = 0.5 + (t * (t * (1.0 + (t * -2.0))));
	} else {
		tmp = 0.8333333333333334 + t_1;
	}
	return tmp;
}
def code(t):
	t_1 = ((0.037037037037037035 / t) + -0.2222222222222222) / t
	tmp = 0
	if t <= -0.6:
		tmp = 1.0 + (-0.16666666666666666 + t_1)
	elif t <= 0.45:
		tmp = 0.5 + (t * (t * (1.0 + (t * -2.0))))
	else:
		tmp = 0.8333333333333334 + t_1
	return tmp
function code(t)
	t_1 = Float64(Float64(Float64(0.037037037037037035 / t) + -0.2222222222222222) / t)
	tmp = 0.0
	if (t <= -0.6)
		tmp = Float64(1.0 + Float64(-0.16666666666666666 + t_1));
	elseif (t <= 0.45)
		tmp = Float64(0.5 + Float64(t * Float64(t * Float64(1.0 + Float64(t * -2.0)))));
	else
		tmp = Float64(0.8333333333333334 + t_1);
	end
	return tmp
end
function tmp_2 = code(t)
	t_1 = ((0.037037037037037035 / t) + -0.2222222222222222) / t;
	tmp = 0.0;
	if (t <= -0.6)
		tmp = 1.0 + (-0.16666666666666666 + t_1);
	elseif (t <= 0.45)
		tmp = 0.5 + (t * (t * (1.0 + (t * -2.0))));
	else
		tmp = 0.8333333333333334 + t_1;
	end
	tmp_2 = tmp;
end
code[t_] := Block[{t$95$1 = N[(N[(N[(0.037037037037037035 / t), $MachinePrecision] + -0.2222222222222222), $MachinePrecision] / t), $MachinePrecision]}, If[LessEqual[t, -0.6], N[(1.0 + N[(-0.16666666666666666 + t$95$1), $MachinePrecision]), $MachinePrecision], If[LessEqual[t, 0.45], N[(0.5 + N[(t * N[(t * N[(1.0 + N[(t * -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(0.8333333333333334 + t$95$1), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{\frac{0.037037037037037035}{t} + -0.2222222222222222}{t}\\
\mathbf{if}\;t \leq -0.6:\\
\;\;\;\;1 + \left(-0.16666666666666666 + t\_1\right)\\

\mathbf{elif}\;t \leq 0.45:\\
\;\;\;\;0.5 + t \cdot \left(t \cdot \left(1 + t \cdot -2\right)\right)\\

\mathbf{else}:\\
\;\;\;\;0.8333333333333334 + t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if t < -0.599999999999999978

    1. Initial program 100.0%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around inf

      \[\leadsto \mathsf{+.f64}\left(1, \color{blue}{\left(\frac{\frac{1}{27}}{{t}^{2}} - \left(\frac{1}{6} + \frac{2}{9} \cdot \frac{1}{t}\right)\right)}\right) \]
    5. Step-by-step derivation
      1. associate--r+N/A

        \[\leadsto \mathsf{+.f64}\left(1, \left(\left(\frac{\frac{1}{27}}{{t}^{2}} - \frac{1}{6}\right) - \color{blue}{\frac{2}{9} \cdot \frac{1}{t}}\right)\right) \]
      2. sub-negN/A

        \[\leadsto \mathsf{+.f64}\left(1, \left(\left(\frac{\frac{1}{27}}{{t}^{2}} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right)\right) - \color{blue}{\frac{2}{9}} \cdot \frac{1}{t}\right)\right) \]
      3. +-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(1, \left(\left(\left(\mathsf{neg}\left(\frac{1}{6}\right)\right) + \frac{\frac{1}{27}}{{t}^{2}}\right) - \color{blue}{\frac{2}{9}} \cdot \frac{1}{t}\right)\right) \]
      4. associate-+r-N/A

        \[\leadsto \mathsf{+.f64}\left(1, \left(\left(\mathsf{neg}\left(\frac{1}{6}\right)\right) + \color{blue}{\left(\frac{\frac{1}{27}}{{t}^{2}} - \frac{2}{9} \cdot \frac{1}{t}\right)}\right)\right) \]
      5. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\left(\mathsf{neg}\left(\frac{1}{6}\right)\right), \color{blue}{\left(\frac{\frac{1}{27}}{{t}^{2}} - \frac{2}{9} \cdot \frac{1}{t}\right)}\right)\right) \]
      6. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(\color{blue}{\frac{\frac{1}{27}}{{t}^{2}}} - \frac{2}{9} \cdot \frac{1}{t}\right)\right)\right) \]
      7. sub-negN/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(\frac{\frac{1}{27}}{{t}^{2}} + \color{blue}{\left(\mathsf{neg}\left(\frac{2}{9} \cdot \frac{1}{t}\right)\right)}\right)\right)\right) \]
      8. +-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(\left(\mathsf{neg}\left(\frac{2}{9} \cdot \frac{1}{t}\right)\right) + \color{blue}{\frac{\frac{1}{27}}{{t}^{2}}}\right)\right)\right) \]
      9. neg-sub0N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(\left(0 - \frac{2}{9} \cdot \frac{1}{t}\right) + \frac{\color{blue}{\frac{1}{27}}}{{t}^{2}}\right)\right)\right) \]
      10. associate--r-N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(0 - \color{blue}{\left(\frac{2}{9} \cdot \frac{1}{t} - \frac{\frac{1}{27}}{{t}^{2}}\right)}\right)\right)\right) \]
      11. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(0 - \left(\frac{\frac{2}{9} \cdot 1}{t} - \frac{\color{blue}{\frac{1}{27}}}{{t}^{2}}\right)\right)\right)\right) \]
      12. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27}}{{t}^{2}}\right)\right)\right)\right) \]
      13. unpow2N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27}}{t \cdot \color{blue}{t}}\right)\right)\right)\right) \]
      14. associate-/r*N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{\frac{1}{27}}{t}}{\color{blue}{t}}\right)\right)\right)\right) \]
      15. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{\frac{1}{27} \cdot 1}{t}}{t}\right)\right)\right)\right) \]
      16. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27} \cdot \frac{1}{t}}{t}\right)\right)\right)\right) \]
      17. div-subN/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(0 - \frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{\color{blue}{t}}\right)\right)\right) \]
      18. neg-sub0N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(\mathsf{neg}\left(\frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{t}\right)\right)\right)\right) \]
      19. distribute-neg-fracN/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(\frac{\mathsf{neg}\left(\left(\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}\right)\right)}{\color{blue}{t}}\right)\right)\right) \]
      20. mul-1-negN/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{+.f64}\left(\frac{-1}{6}, \left(\frac{-1 \cdot \left(\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}\right)}{t}\right)\right)\right) \]
    6. Simplified99.7%

      \[\leadsto 1 + \color{blue}{\left(-0.16666666666666666 + \frac{\frac{0.037037037037037035}{t} + -0.2222222222222222}{t}\right)} \]

    if -0.599999999999999978 < t < 0.450000000000000011

    1. Initial program 100.0%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around 0

      \[\leadsto \color{blue}{\frac{1}{2} + {t}^{2} \cdot \left(1 + -2 \cdot t\right)} \]
    5. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \color{blue}{\left({t}^{2} \cdot \left(1 + -2 \cdot t\right)\right)}\right) \]
      2. unpow2N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \left(\left(t \cdot t\right) \cdot \left(\color{blue}{1} + -2 \cdot t\right)\right)\right) \]
      3. associate-*l*N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \left(t \cdot \color{blue}{\left(t \cdot \left(1 + -2 \cdot t\right)\right)}\right)\right) \]
      4. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \left(t \cdot \left(\left(1 + -2 \cdot t\right) \cdot \color{blue}{t}\right)\right)\right) \]
      5. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(t, \color{blue}{\left(\left(1 + -2 \cdot t\right) \cdot t\right)}\right)\right) \]
      6. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(t, \left(t \cdot \color{blue}{\left(1 + -2 \cdot t\right)}\right)\right)\right) \]
      7. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(t, \mathsf{*.f64}\left(t, \color{blue}{\left(1 + -2 \cdot t\right)}\right)\right)\right) \]
      8. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(t, \mathsf{*.f64}\left(t, \mathsf{+.f64}\left(1, \color{blue}{\left(-2 \cdot t\right)}\right)\right)\right)\right) \]
      9. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(t, \mathsf{*.f64}\left(t, \mathsf{+.f64}\left(1, \left(t \cdot \color{blue}{-2}\right)\right)\right)\right)\right) \]
      10. *-lowering-*.f6499.4%

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(t, \mathsf{*.f64}\left(t, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(t, \color{blue}{-2}\right)\right)\right)\right)\right) \]
    6. Simplified99.4%

      \[\leadsto \color{blue}{0.5 + t \cdot \left(t \cdot \left(1 + t \cdot -2\right)\right)} \]

    if 0.450000000000000011 < t

    1. Initial program 100.0%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around inf

      \[\leadsto \color{blue}{\left(\frac{5}{6} + \frac{\frac{1}{27}}{{t}^{2}}\right) - \frac{2}{9} \cdot \frac{1}{t}} \]
    5. Step-by-step derivation
      1. associate--l+N/A

        \[\leadsto \frac{5}{6} + \color{blue}{\left(\frac{\frac{1}{27}}{{t}^{2}} - \frac{2}{9} \cdot \frac{1}{t}\right)} \]
      2. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \color{blue}{\left(\frac{\frac{1}{27}}{{t}^{2}} - \frac{2}{9} \cdot \frac{1}{t}\right)}\right) \]
      3. sub-negN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\frac{\frac{1}{27}}{{t}^{2}} + \color{blue}{\left(\mathsf{neg}\left(\frac{2}{9} \cdot \frac{1}{t}\right)\right)}\right)\right) \]
      4. +-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\left(\mathsf{neg}\left(\frac{2}{9} \cdot \frac{1}{t}\right)\right) + \color{blue}{\frac{\frac{1}{27}}{{t}^{2}}}\right)\right) \]
      5. neg-sub0N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\left(0 - \frac{2}{9} \cdot \frac{1}{t}\right) + \frac{\color{blue}{\frac{1}{27}}}{{t}^{2}}\right)\right) \]
      6. associate--r-N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \color{blue}{\left(\frac{2}{9} \cdot \frac{1}{t} - \frac{\frac{1}{27}}{{t}^{2}}\right)}\right)\right) \]
      7. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9} \cdot 1}{t} - \frac{\color{blue}{\frac{1}{27}}}{{t}^{2}}\right)\right)\right) \]
      8. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27}}{{t}^{2}}\right)\right)\right) \]
      9. unpow2N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27}}{t \cdot \color{blue}{t}}\right)\right)\right) \]
      10. associate-/r*N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{\frac{1}{27}}{t}}{\color{blue}{t}}\right)\right)\right) \]
      11. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{\frac{1}{27} \cdot 1}{t}}{t}\right)\right)\right) \]
      12. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27} \cdot \frac{1}{t}}{t}\right)\right)\right) \]
      13. div-subN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{\color{blue}{t}}\right)\right) \]
      14. neg-sub0N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\mathsf{neg}\left(\frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{t}\right)\right)\right) \]
      15. distribute-neg-fracN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\frac{\mathsf{neg}\left(\left(\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}\right)\right)}{\color{blue}{t}}\right)\right) \]
      16. mul-1-negN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\frac{-1 \cdot \left(\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}\right)}{t}\right)\right) \]
    6. Simplified99.7%

      \[\leadsto \color{blue}{0.8333333333333334 + \frac{\frac{0.037037037037037035}{t} + -0.2222222222222222}{t}} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 5: 99.6% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := 0.8333333333333334 + \frac{\frac{0.037037037037037035}{t} + -0.2222222222222222}{t}\\ \mathbf{if}\;t \leq -0.6:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;t \leq 0.45:\\ \;\;\;\;0.5 + t \cdot \left(t \cdot \left(1 + t \cdot -2\right)\right)\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1
         (+
          0.8333333333333334
          (/ (+ (/ 0.037037037037037035 t) -0.2222222222222222) t))))
   (if (<= t -0.6)
     t_1
     (if (<= t 0.45) (+ 0.5 (* t (* t (+ 1.0 (* t -2.0))))) t_1))))
double code(double t) {
	double t_1 = 0.8333333333333334 + (((0.037037037037037035 / t) + -0.2222222222222222) / t);
	double tmp;
	if (t <= -0.6) {
		tmp = t_1;
	} else if (t <= 0.45) {
		tmp = 0.5 + (t * (t * (1.0 + (t * -2.0))));
	} else {
		tmp = t_1;
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: tmp
    t_1 = 0.8333333333333334d0 + (((0.037037037037037035d0 / t) + (-0.2222222222222222d0)) / t)
    if (t <= (-0.6d0)) then
        tmp = t_1
    else if (t <= 0.45d0) then
        tmp = 0.5d0 + (t * (t * (1.0d0 + (t * (-2.0d0)))))
    else
        tmp = t_1
    end if
    code = tmp
end function
public static double code(double t) {
	double t_1 = 0.8333333333333334 + (((0.037037037037037035 / t) + -0.2222222222222222) / t);
	double tmp;
	if (t <= -0.6) {
		tmp = t_1;
	} else if (t <= 0.45) {
		tmp = 0.5 + (t * (t * (1.0 + (t * -2.0))));
	} else {
		tmp = t_1;
	}
	return tmp;
}
def code(t):
	t_1 = 0.8333333333333334 + (((0.037037037037037035 / t) + -0.2222222222222222) / t)
	tmp = 0
	if t <= -0.6:
		tmp = t_1
	elif t <= 0.45:
		tmp = 0.5 + (t * (t * (1.0 + (t * -2.0))))
	else:
		tmp = t_1
	return tmp
function code(t)
	t_1 = Float64(0.8333333333333334 + Float64(Float64(Float64(0.037037037037037035 / t) + -0.2222222222222222) / t))
	tmp = 0.0
	if (t <= -0.6)
		tmp = t_1;
	elseif (t <= 0.45)
		tmp = Float64(0.5 + Float64(t * Float64(t * Float64(1.0 + Float64(t * -2.0)))));
	else
		tmp = t_1;
	end
	return tmp
end
function tmp_2 = code(t)
	t_1 = 0.8333333333333334 + (((0.037037037037037035 / t) + -0.2222222222222222) / t);
	tmp = 0.0;
	if (t <= -0.6)
		tmp = t_1;
	elseif (t <= 0.45)
		tmp = 0.5 + (t * (t * (1.0 + (t * -2.0))));
	else
		tmp = t_1;
	end
	tmp_2 = tmp;
end
code[t_] := Block[{t$95$1 = N[(0.8333333333333334 + N[(N[(N[(0.037037037037037035 / t), $MachinePrecision] + -0.2222222222222222), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t, -0.6], t$95$1, If[LessEqual[t, 0.45], N[(0.5 + N[(t * N[(t * N[(1.0 + N[(t * -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$1]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := 0.8333333333333334 + \frac{\frac{0.037037037037037035}{t} + -0.2222222222222222}{t}\\
\mathbf{if}\;t \leq -0.6:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;t \leq 0.45:\\
\;\;\;\;0.5 + t \cdot \left(t \cdot \left(1 + t \cdot -2\right)\right)\\

\mathbf{else}:\\
\;\;\;\;t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < -0.599999999999999978 or 0.450000000000000011 < t

    1. Initial program 100.0%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around inf

      \[\leadsto \color{blue}{\left(\frac{5}{6} + \frac{\frac{1}{27}}{{t}^{2}}\right) - \frac{2}{9} \cdot \frac{1}{t}} \]
    5. Step-by-step derivation
      1. associate--l+N/A

        \[\leadsto \frac{5}{6} + \color{blue}{\left(\frac{\frac{1}{27}}{{t}^{2}} - \frac{2}{9} \cdot \frac{1}{t}\right)} \]
      2. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \color{blue}{\left(\frac{\frac{1}{27}}{{t}^{2}} - \frac{2}{9} \cdot \frac{1}{t}\right)}\right) \]
      3. sub-negN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\frac{\frac{1}{27}}{{t}^{2}} + \color{blue}{\left(\mathsf{neg}\left(\frac{2}{9} \cdot \frac{1}{t}\right)\right)}\right)\right) \]
      4. +-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\left(\mathsf{neg}\left(\frac{2}{9} \cdot \frac{1}{t}\right)\right) + \color{blue}{\frac{\frac{1}{27}}{{t}^{2}}}\right)\right) \]
      5. neg-sub0N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\left(0 - \frac{2}{9} \cdot \frac{1}{t}\right) + \frac{\color{blue}{\frac{1}{27}}}{{t}^{2}}\right)\right) \]
      6. associate--r-N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \color{blue}{\left(\frac{2}{9} \cdot \frac{1}{t} - \frac{\frac{1}{27}}{{t}^{2}}\right)}\right)\right) \]
      7. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9} \cdot 1}{t} - \frac{\color{blue}{\frac{1}{27}}}{{t}^{2}}\right)\right)\right) \]
      8. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27}}{{t}^{2}}\right)\right)\right) \]
      9. unpow2N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27}}{t \cdot \color{blue}{t}}\right)\right)\right) \]
      10. associate-/r*N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{\frac{1}{27}}{t}}{\color{blue}{t}}\right)\right)\right) \]
      11. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{\frac{1}{27} \cdot 1}{t}}{t}\right)\right)\right) \]
      12. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27} \cdot \frac{1}{t}}{t}\right)\right)\right) \]
      13. div-subN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{\color{blue}{t}}\right)\right) \]
      14. neg-sub0N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\mathsf{neg}\left(\frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{t}\right)\right)\right) \]
      15. distribute-neg-fracN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\frac{\mathsf{neg}\left(\left(\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}\right)\right)}{\color{blue}{t}}\right)\right) \]
      16. mul-1-negN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\frac{-1 \cdot \left(\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}\right)}{t}\right)\right) \]
    6. Simplified99.7%

      \[\leadsto \color{blue}{0.8333333333333334 + \frac{\frac{0.037037037037037035}{t} + -0.2222222222222222}{t}} \]

    if -0.599999999999999978 < t < 0.450000000000000011

    1. Initial program 100.0%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around 0

      \[\leadsto \color{blue}{\frac{1}{2} + {t}^{2} \cdot \left(1 + -2 \cdot t\right)} \]
    5. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \color{blue}{\left({t}^{2} \cdot \left(1 + -2 \cdot t\right)\right)}\right) \]
      2. unpow2N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \left(\left(t \cdot t\right) \cdot \left(\color{blue}{1} + -2 \cdot t\right)\right)\right) \]
      3. associate-*l*N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \left(t \cdot \color{blue}{\left(t \cdot \left(1 + -2 \cdot t\right)\right)}\right)\right) \]
      4. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \left(t \cdot \left(\left(1 + -2 \cdot t\right) \cdot \color{blue}{t}\right)\right)\right) \]
      5. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(t, \color{blue}{\left(\left(1 + -2 \cdot t\right) \cdot t\right)}\right)\right) \]
      6. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(t, \left(t \cdot \color{blue}{\left(1 + -2 \cdot t\right)}\right)\right)\right) \]
      7. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(t, \mathsf{*.f64}\left(t, \color{blue}{\left(1 + -2 \cdot t\right)}\right)\right)\right) \]
      8. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(t, \mathsf{*.f64}\left(t, \mathsf{+.f64}\left(1, \color{blue}{\left(-2 \cdot t\right)}\right)\right)\right)\right) \]
      9. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(t, \mathsf{*.f64}\left(t, \mathsf{+.f64}\left(1, \left(t \cdot \color{blue}{-2}\right)\right)\right)\right)\right) \]
      10. *-lowering-*.f6499.4%

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(t, \mathsf{*.f64}\left(t, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(t, \color{blue}{-2}\right)\right)\right)\right)\right) \]
    6. Simplified99.4%

      \[\leadsto \color{blue}{0.5 + t \cdot \left(t \cdot \left(1 + t \cdot -2\right)\right)} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 6: 99.5% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := 0.8333333333333334 + \frac{\frac{0.037037037037037035}{t} + -0.2222222222222222}{t}\\ \mathbf{if}\;t \leq -0.82:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;t \leq 0.235:\\ \;\;\;\;0.5 + t \cdot t\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1
         (+
          0.8333333333333334
          (/ (+ (/ 0.037037037037037035 t) -0.2222222222222222) t))))
   (if (<= t -0.82) t_1 (if (<= t 0.235) (+ 0.5 (* t t)) t_1))))
double code(double t) {
	double t_1 = 0.8333333333333334 + (((0.037037037037037035 / t) + -0.2222222222222222) / t);
	double tmp;
	if (t <= -0.82) {
		tmp = t_1;
	} else if (t <= 0.235) {
		tmp = 0.5 + (t * t);
	} else {
		tmp = t_1;
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: tmp
    t_1 = 0.8333333333333334d0 + (((0.037037037037037035d0 / t) + (-0.2222222222222222d0)) / t)
    if (t <= (-0.82d0)) then
        tmp = t_1
    else if (t <= 0.235d0) then
        tmp = 0.5d0 + (t * t)
    else
        tmp = t_1
    end if
    code = tmp
end function
public static double code(double t) {
	double t_1 = 0.8333333333333334 + (((0.037037037037037035 / t) + -0.2222222222222222) / t);
	double tmp;
	if (t <= -0.82) {
		tmp = t_1;
	} else if (t <= 0.235) {
		tmp = 0.5 + (t * t);
	} else {
		tmp = t_1;
	}
	return tmp;
}
def code(t):
	t_1 = 0.8333333333333334 + (((0.037037037037037035 / t) + -0.2222222222222222) / t)
	tmp = 0
	if t <= -0.82:
		tmp = t_1
	elif t <= 0.235:
		tmp = 0.5 + (t * t)
	else:
		tmp = t_1
	return tmp
function code(t)
	t_1 = Float64(0.8333333333333334 + Float64(Float64(Float64(0.037037037037037035 / t) + -0.2222222222222222) / t))
	tmp = 0.0
	if (t <= -0.82)
		tmp = t_1;
	elseif (t <= 0.235)
		tmp = Float64(0.5 + Float64(t * t));
	else
		tmp = t_1;
	end
	return tmp
end
function tmp_2 = code(t)
	t_1 = 0.8333333333333334 + (((0.037037037037037035 / t) + -0.2222222222222222) / t);
	tmp = 0.0;
	if (t <= -0.82)
		tmp = t_1;
	elseif (t <= 0.235)
		tmp = 0.5 + (t * t);
	else
		tmp = t_1;
	end
	tmp_2 = tmp;
end
code[t_] := Block[{t$95$1 = N[(0.8333333333333334 + N[(N[(N[(0.037037037037037035 / t), $MachinePrecision] + -0.2222222222222222), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t, -0.82], t$95$1, If[LessEqual[t, 0.235], N[(0.5 + N[(t * t), $MachinePrecision]), $MachinePrecision], t$95$1]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := 0.8333333333333334 + \frac{\frac{0.037037037037037035}{t} + -0.2222222222222222}{t}\\
\mathbf{if}\;t \leq -0.82:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;t \leq 0.235:\\
\;\;\;\;0.5 + t \cdot t\\

\mathbf{else}:\\
\;\;\;\;t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < -0.819999999999999951 or 0.23499999999999999 < t

    1. Initial program 100.0%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around inf

      \[\leadsto \color{blue}{\left(\frac{5}{6} + \frac{\frac{1}{27}}{{t}^{2}}\right) - \frac{2}{9} \cdot \frac{1}{t}} \]
    5. Step-by-step derivation
      1. associate--l+N/A

        \[\leadsto \frac{5}{6} + \color{blue}{\left(\frac{\frac{1}{27}}{{t}^{2}} - \frac{2}{9} \cdot \frac{1}{t}\right)} \]
      2. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \color{blue}{\left(\frac{\frac{1}{27}}{{t}^{2}} - \frac{2}{9} \cdot \frac{1}{t}\right)}\right) \]
      3. sub-negN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\frac{\frac{1}{27}}{{t}^{2}} + \color{blue}{\left(\mathsf{neg}\left(\frac{2}{9} \cdot \frac{1}{t}\right)\right)}\right)\right) \]
      4. +-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\left(\mathsf{neg}\left(\frac{2}{9} \cdot \frac{1}{t}\right)\right) + \color{blue}{\frac{\frac{1}{27}}{{t}^{2}}}\right)\right) \]
      5. neg-sub0N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\left(0 - \frac{2}{9} \cdot \frac{1}{t}\right) + \frac{\color{blue}{\frac{1}{27}}}{{t}^{2}}\right)\right) \]
      6. associate--r-N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \color{blue}{\left(\frac{2}{9} \cdot \frac{1}{t} - \frac{\frac{1}{27}}{{t}^{2}}\right)}\right)\right) \]
      7. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9} \cdot 1}{t} - \frac{\color{blue}{\frac{1}{27}}}{{t}^{2}}\right)\right)\right) \]
      8. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27}}{{t}^{2}}\right)\right)\right) \]
      9. unpow2N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27}}{t \cdot \color{blue}{t}}\right)\right)\right) \]
      10. associate-/r*N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{\frac{1}{27}}{t}}{\color{blue}{t}}\right)\right)\right) \]
      11. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{\frac{1}{27} \cdot 1}{t}}{t}\right)\right)\right) \]
      12. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27} \cdot \frac{1}{t}}{t}\right)\right)\right) \]
      13. div-subN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(0 - \frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{\color{blue}{t}}\right)\right) \]
      14. neg-sub0N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\mathsf{neg}\left(\frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{t}\right)\right)\right) \]
      15. distribute-neg-fracN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\frac{\mathsf{neg}\left(\left(\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}\right)\right)}{\color{blue}{t}}\right)\right) \]
      16. mul-1-negN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\frac{-1 \cdot \left(\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}\right)}{t}\right)\right) \]
    6. Simplified99.1%

      \[\leadsto \color{blue}{0.8333333333333334 + \frac{\frac{0.037037037037037035}{t} + -0.2222222222222222}{t}} \]

    if -0.819999999999999951 < t < 0.23499999999999999

    1. Initial program 100.0%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around 0

      \[\leadsto \color{blue}{\frac{1}{2} + {t}^{2}} \]
    5. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \color{blue}{\left({t}^{2}\right)}\right) \]
      2. unpow2N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \left(t \cdot \color{blue}{t}\right)\right) \]
      3. *-lowering-*.f6499.9%

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(t, \color{blue}{t}\right)\right) \]
    6. Simplified99.9%

      \[\leadsto \color{blue}{0.5 + t \cdot t} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 7: 99.3% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := 0.8333333333333334 + \frac{-0.2222222222222222}{t}\\ \mathbf{if}\;t \leq -0.8:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;t \leq 0.55:\\ \;\;\;\;0.5 + t \cdot t\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (+ 0.8333333333333334 (/ -0.2222222222222222 t))))
   (if (<= t -0.8) t_1 (if (<= t 0.55) (+ 0.5 (* t t)) t_1))))
double code(double t) {
	double t_1 = 0.8333333333333334 + (-0.2222222222222222 / t);
	double tmp;
	if (t <= -0.8) {
		tmp = t_1;
	} else if (t <= 0.55) {
		tmp = 0.5 + (t * t);
	} else {
		tmp = t_1;
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: tmp
    t_1 = 0.8333333333333334d0 + ((-0.2222222222222222d0) / t)
    if (t <= (-0.8d0)) then
        tmp = t_1
    else if (t <= 0.55d0) then
        tmp = 0.5d0 + (t * t)
    else
        tmp = t_1
    end if
    code = tmp
end function
public static double code(double t) {
	double t_1 = 0.8333333333333334 + (-0.2222222222222222 / t);
	double tmp;
	if (t <= -0.8) {
		tmp = t_1;
	} else if (t <= 0.55) {
		tmp = 0.5 + (t * t);
	} else {
		tmp = t_1;
	}
	return tmp;
}
def code(t):
	t_1 = 0.8333333333333334 + (-0.2222222222222222 / t)
	tmp = 0
	if t <= -0.8:
		tmp = t_1
	elif t <= 0.55:
		tmp = 0.5 + (t * t)
	else:
		tmp = t_1
	return tmp
function code(t)
	t_1 = Float64(0.8333333333333334 + Float64(-0.2222222222222222 / t))
	tmp = 0.0
	if (t <= -0.8)
		tmp = t_1;
	elseif (t <= 0.55)
		tmp = Float64(0.5 + Float64(t * t));
	else
		tmp = t_1;
	end
	return tmp
end
function tmp_2 = code(t)
	t_1 = 0.8333333333333334 + (-0.2222222222222222 / t);
	tmp = 0.0;
	if (t <= -0.8)
		tmp = t_1;
	elseif (t <= 0.55)
		tmp = 0.5 + (t * t);
	else
		tmp = t_1;
	end
	tmp_2 = tmp;
end
code[t_] := Block[{t$95$1 = N[(0.8333333333333334 + N[(-0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t, -0.8], t$95$1, If[LessEqual[t, 0.55], N[(0.5 + N[(t * t), $MachinePrecision]), $MachinePrecision], t$95$1]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := 0.8333333333333334 + \frac{-0.2222222222222222}{t}\\
\mathbf{if}\;t \leq -0.8:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;t \leq 0.55:\\
\;\;\;\;0.5 + t \cdot t\\

\mathbf{else}:\\
\;\;\;\;t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < -0.80000000000000004 or 0.55000000000000004 < t

    1. Initial program 100.0%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around inf

      \[\leadsto \color{blue}{\frac{5}{6} - \frac{2}{9} \cdot \frac{1}{t}} \]
    5. Step-by-step derivation
      1. sub-negN/A

        \[\leadsto \frac{5}{6} + \color{blue}{\left(\mathsf{neg}\left(\frac{2}{9} \cdot \frac{1}{t}\right)\right)} \]
      2. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \color{blue}{\left(\mathsf{neg}\left(\frac{2}{9} \cdot \frac{1}{t}\right)\right)}\right) \]
      3. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\mathsf{neg}\left(\frac{\frac{2}{9} \cdot 1}{t}\right)\right)\right) \]
      4. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\mathsf{neg}\left(\frac{\frac{2}{9}}{t}\right)\right)\right) \]
      5. distribute-neg-fracN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \left(\frac{\mathsf{neg}\left(\frac{2}{9}\right)}{\color{blue}{t}}\right)\right) \]
      6. /-lowering-/.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \mathsf{/.f64}\left(\left(\mathsf{neg}\left(\frac{2}{9}\right)\right), \color{blue}{t}\right)\right) \]
      7. metadata-eval99.3%

        \[\leadsto \mathsf{+.f64}\left(\frac{5}{6}, \mathsf{/.f64}\left(\frac{-2}{9}, t\right)\right) \]
    6. Simplified99.3%

      \[\leadsto \color{blue}{0.8333333333333334 + \frac{-0.2222222222222222}{t}} \]

    if -0.80000000000000004 < t < 0.55000000000000004

    1. Initial program 100.0%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around 0

      \[\leadsto \color{blue}{\frac{1}{2} + {t}^{2}} \]
    5. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \color{blue}{\left({t}^{2}\right)}\right) \]
      2. unpow2N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \left(t \cdot \color{blue}{t}\right)\right) \]
      3. *-lowering-*.f6499.3%

        \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(t, \color{blue}{t}\right)\right) \]
    6. Simplified99.3%

      \[\leadsto \color{blue}{0.5 + t \cdot t} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 8: 98.8% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq -0.92:\\ \;\;\;\;0.8333333333333334\\ \mathbf{elif}\;t \leq 0.6:\\ \;\;\;\;0.5 + t \cdot t\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (<= t -0.92)
   0.8333333333333334
   (if (<= t 0.6) (+ 0.5 (* t t)) 0.8333333333333334)))
double code(double t) {
	double tmp;
	if (t <= -0.92) {
		tmp = 0.8333333333333334;
	} else if (t <= 0.6) {
		tmp = 0.5 + (t * t);
	} else {
		tmp = 0.8333333333333334;
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: tmp
    if (t <= (-0.92d0)) then
        tmp = 0.8333333333333334d0
    else if (t <= 0.6d0) then
        tmp = 0.5d0 + (t * t)
    else
        tmp = 0.8333333333333334d0
    end if
    code = tmp
end function
public static double code(double t) {
	double tmp;
	if (t <= -0.92) {
		tmp = 0.8333333333333334;
	} else if (t <= 0.6) {
		tmp = 0.5 + (t * t);
	} else {
		tmp = 0.8333333333333334;
	}
	return tmp;
}
def code(t):
	tmp = 0
	if t <= -0.92:
		tmp = 0.8333333333333334
	elif t <= 0.6:
		tmp = 0.5 + (t * t)
	else:
		tmp = 0.8333333333333334
	return tmp
function code(t)
	tmp = 0.0
	if (t <= -0.92)
		tmp = 0.8333333333333334;
	elseif (t <= 0.6)
		tmp = Float64(0.5 + Float64(t * t));
	else
		tmp = 0.8333333333333334;
	end
	return tmp
end
function tmp_2 = code(t)
	tmp = 0.0;
	if (t <= -0.92)
		tmp = 0.8333333333333334;
	elseif (t <= 0.6)
		tmp = 0.5 + (t * t);
	else
		tmp = 0.8333333333333334;
	end
	tmp_2 = tmp;
end
code[t_] := If[LessEqual[t, -0.92], 0.8333333333333334, If[LessEqual[t, 0.6], N[(0.5 + N[(t * t), $MachinePrecision]), $MachinePrecision], 0.8333333333333334]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.92:\\
\;\;\;\;0.8333333333333334\\

\mathbf{elif}\;t \leq 0.6:\\
\;\;\;\;0.5 + t \cdot t\\

\mathbf{else}:\\
\;\;\;\;0.8333333333333334\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < -0.92000000000000004 or 0.599999999999999978 < t

    1. Initial program 100.0%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around inf

      \[\leadsto \color{blue}{\frac{5}{6}} \]
    5. Step-by-step derivation
      1. Simplified97.9%

        \[\leadsto \color{blue}{0.8333333333333334} \]

      if -0.92000000000000004 < t < 0.599999999999999978

      1. Initial program 100.0%

        \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
      2. Simplified100.0%

        \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
      3. Add Preprocessing
      4. Taylor expanded in t around 0

        \[\leadsto \color{blue}{\frac{1}{2} + {t}^{2}} \]
      5. Step-by-step derivation
        1. +-lowering-+.f64N/A

          \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \color{blue}{\left({t}^{2}\right)}\right) \]
        2. unpow2N/A

          \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \left(t \cdot \color{blue}{t}\right)\right) \]
        3. *-lowering-*.f6499.3%

          \[\leadsto \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(t, \color{blue}{t}\right)\right) \]
      6. Simplified99.3%

        \[\leadsto \color{blue}{0.5 + t \cdot t} \]
    6. Recombined 2 regimes into one program.
    7. Add Preprocessing

    Alternative 9: 98.7% accurate, 2.6× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq -0.33:\\ \;\;\;\;0.8333333333333334\\ \mathbf{elif}\;t \leq 1:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334\\ \end{array} \end{array} \]
    (FPCore (t)
     :precision binary64
     (if (<= t -0.33) 0.8333333333333334 (if (<= t 1.0) 0.5 0.8333333333333334)))
    double code(double t) {
    	double tmp;
    	if (t <= -0.33) {
    		tmp = 0.8333333333333334;
    	} else if (t <= 1.0) {
    		tmp = 0.5;
    	} else {
    		tmp = 0.8333333333333334;
    	}
    	return tmp;
    }
    
    real(8) function code(t)
        real(8), intent (in) :: t
        real(8) :: tmp
        if (t <= (-0.33d0)) then
            tmp = 0.8333333333333334d0
        else if (t <= 1.0d0) then
            tmp = 0.5d0
        else
            tmp = 0.8333333333333334d0
        end if
        code = tmp
    end function
    
    public static double code(double t) {
    	double tmp;
    	if (t <= -0.33) {
    		tmp = 0.8333333333333334;
    	} else if (t <= 1.0) {
    		tmp = 0.5;
    	} else {
    		tmp = 0.8333333333333334;
    	}
    	return tmp;
    }
    
    def code(t):
    	tmp = 0
    	if t <= -0.33:
    		tmp = 0.8333333333333334
    	elif t <= 1.0:
    		tmp = 0.5
    	else:
    		tmp = 0.8333333333333334
    	return tmp
    
    function code(t)
    	tmp = 0.0
    	if (t <= -0.33)
    		tmp = 0.8333333333333334;
    	elseif (t <= 1.0)
    		tmp = 0.5;
    	else
    		tmp = 0.8333333333333334;
    	end
    	return tmp
    end
    
    function tmp_2 = code(t)
    	tmp = 0.0;
    	if (t <= -0.33)
    		tmp = 0.8333333333333334;
    	elseif (t <= 1.0)
    		tmp = 0.5;
    	else
    		tmp = 0.8333333333333334;
    	end
    	tmp_2 = tmp;
    end
    
    code[t_] := If[LessEqual[t, -0.33], 0.8333333333333334, If[LessEqual[t, 1.0], 0.5, 0.8333333333333334]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;t \leq -0.33:\\
    \;\;\;\;0.8333333333333334\\
    
    \mathbf{elif}\;t \leq 1:\\
    \;\;\;\;0.5\\
    
    \mathbf{else}:\\
    \;\;\;\;0.8333333333333334\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if t < -0.330000000000000016 or 1 < t

      1. Initial program 100.0%

        \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
      2. Simplified100.0%

        \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
      3. Add Preprocessing
      4. Taylor expanded in t around inf

        \[\leadsto \color{blue}{\frac{5}{6}} \]
      5. Step-by-step derivation
        1. Simplified97.9%

          \[\leadsto \color{blue}{0.8333333333333334} \]

        if -0.330000000000000016 < t < 1

        1. Initial program 100.0%

          \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
        2. Simplified100.0%

          \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
        3. Add Preprocessing
        4. Taylor expanded in t around 0

          \[\leadsto \color{blue}{\frac{1}{2}} \]
        5. Step-by-step derivation
          1. Simplified98.8%

            \[\leadsto \color{blue}{0.5} \]
        6. Recombined 2 regimes into one program.
        7. Add Preprocessing

        Alternative 10: 58.4% accurate, 29.0× speedup?

        \[\begin{array}{l} \\ 0.5 \end{array} \]
        (FPCore (t) :precision binary64 0.5)
        double code(double t) {
        	return 0.5;
        }
        
        real(8) function code(t)
            real(8), intent (in) :: t
            code = 0.5d0
        end function
        
        public static double code(double t) {
        	return 0.5;
        }
        
        def code(t):
        	return 0.5
        
        function code(t)
        	return 0.5
        end
        
        function tmp = code(t)
        	tmp = 0.5;
        end
        
        code[t_] := 0.5
        
        \begin{array}{l}
        
        \\
        0.5
        \end{array}
        
        Derivation
        1. Initial program 100.0%

          \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
        2. Simplified100.0%

          \[\leadsto \color{blue}{1 + \frac{1}{-6 + \frac{2}{1 + t} \cdot \left(\frac{2}{-1 - t} + 4\right)}} \]
        3. Add Preprocessing
        4. Taylor expanded in t around 0

          \[\leadsto \color{blue}{\frac{1}{2}} \]
        5. Step-by-step derivation
          1. Simplified58.6%

            \[\leadsto \color{blue}{0.5} \]
          2. Add Preprocessing

          Reproduce

          ?
          herbie shell --seed 2024155 
          (FPCore (t)
            :name "Kahan p13 Example 3"
            :precision binary64
            (- 1.0 (/ 1.0 (+ 2.0 (* (- 2.0 (/ (/ 2.0 t) (+ 1.0 (/ 1.0 t)))) (- 2.0 (/ (/ 2.0 t) (+ 1.0 (/ 1.0 t)))))))))