Kahan p13 Example 3

Percentage Accurate: 100.0% → 100.0%
Time: 14.6s
Alternatives: 11
Speedup: 0.2×

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 11 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 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, 0.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := 2 + \frac{-2}{1 + t}\\ 1 + \frac{-1}{\mathsf{fma}\left(t\_1, t\_1, 2\right)} \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (+ 2.0 (/ -2.0 (+ 1.0 t))))) (+ 1.0 (/ -1.0 (fma t_1 t_1 2.0)))))
double code(double t) {
	double t_1 = 2.0 + (-2.0 / (1.0 + t));
	return 1.0 + (-1.0 / fma(t_1, t_1, 2.0));
}
function code(t)
	t_1 = Float64(2.0 + Float64(-2.0 / Float64(1.0 + t)))
	return Float64(1.0 + Float64(-1.0 / fma(t_1, t_1, 2.0)))
end
code[t_] := Block[{t$95$1 = N[(2.0 + N[(-2.0 / N[(1.0 + t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(1.0 + N[(-1.0 / N[(t$95$1 * t$95$1 + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := 2 + \frac{-2}{1 + t}\\
1 + \frac{-1}{\mathsf{fma}\left(t\_1, t\_1, 2\right)}
\end{array}
\end{array}
Derivation
  1. Initial program 99.6%

    \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
  2. Step-by-step derivation
    1. sub-neg99.6%

      \[\leadsto \color{blue}{1 + \left(-\frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}\right)} \]
    2. distribute-neg-frac99.6%

      \[\leadsto 1 + \color{blue}{\frac{-1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}} \]
    3. metadata-eval99.6%

      \[\leadsto 1 + \frac{\color{blue}{-1}}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    4. +-commutative99.6%

      \[\leadsto 1 + \frac{-1}{\color{blue}{\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) + 2}} \]
    5. fma-define99.6%

      \[\leadsto 1 + \frac{-1}{\color{blue}{\mathsf{fma}\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{1 + \frac{-1}{\mathsf{fma}\left(2 - \frac{-2}{-1 - t}, 2 - \frac{-2}{-1 - t}, 2\right)}} \]
  4. Add Preprocessing
  5. Final simplification100.0%

    \[\leadsto 1 + \frac{-1}{\mathsf{fma}\left(2 + \frac{-2}{1 + t}, 2 + \frac{-2}{1 + t}, 2\right)} \]
  6. Add Preprocessing

Alternative 2: 99.4% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq -0.75 \lor \neg \left(t \leq 0.82\right):\\ \;\;\;\;1 + \left(-0.16666666666666666 + \frac{\frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{t} - 0.2222222222222222}{t}\right)\\ \mathbf{else}:\\ \;\;\;\;1 + \frac{1}{t \cdot \left(\frac{-4}{-1 - t} - 4\right) - 2}\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (or (<= t -0.75) (not (<= t 0.82)))
   (+
    1.0
    (+
     -0.16666666666666666
     (/
      (-
       (/ (+ 0.037037037037037035 (/ 0.04938271604938271 t)) t)
       0.2222222222222222)
      t)))
   (+ 1.0 (/ 1.0 (- (* t (- (/ -4.0 (- -1.0 t)) 4.0)) 2.0)))))
double code(double t) {
	double tmp;
	if ((t <= -0.75) || !(t <= 0.82)) {
		tmp = 1.0 + (-0.16666666666666666 + ((((0.037037037037037035 + (0.04938271604938271 / t)) / t) - 0.2222222222222222) / t));
	} else {
		tmp = 1.0 + (1.0 / ((t * ((-4.0 / (-1.0 - t)) - 4.0)) - 2.0));
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: tmp
    if ((t <= (-0.75d0)) .or. (.not. (t <= 0.82d0))) then
        tmp = 1.0d0 + ((-0.16666666666666666d0) + ((((0.037037037037037035d0 + (0.04938271604938271d0 / t)) / t) - 0.2222222222222222d0) / t))
    else
        tmp = 1.0d0 + (1.0d0 / ((t * (((-4.0d0) / ((-1.0d0) - t)) - 4.0d0)) - 2.0d0))
    end if
    code = tmp
end function
public static double code(double t) {
	double tmp;
	if ((t <= -0.75) || !(t <= 0.82)) {
		tmp = 1.0 + (-0.16666666666666666 + ((((0.037037037037037035 + (0.04938271604938271 / t)) / t) - 0.2222222222222222) / t));
	} else {
		tmp = 1.0 + (1.0 / ((t * ((-4.0 / (-1.0 - t)) - 4.0)) - 2.0));
	}
	return tmp;
}
def code(t):
	tmp = 0
	if (t <= -0.75) or not (t <= 0.82):
		tmp = 1.0 + (-0.16666666666666666 + ((((0.037037037037037035 + (0.04938271604938271 / t)) / t) - 0.2222222222222222) / t))
	else:
		tmp = 1.0 + (1.0 / ((t * ((-4.0 / (-1.0 - t)) - 4.0)) - 2.0))
	return tmp
function code(t)
	tmp = 0.0
	if ((t <= -0.75) || !(t <= 0.82))
		tmp = Float64(1.0 + Float64(-0.16666666666666666 + Float64(Float64(Float64(Float64(0.037037037037037035 + Float64(0.04938271604938271 / t)) / t) - 0.2222222222222222) / t)));
	else
		tmp = Float64(1.0 + Float64(1.0 / Float64(Float64(t * Float64(Float64(-4.0 / Float64(-1.0 - t)) - 4.0)) - 2.0)));
	end
	return tmp
end
function tmp_2 = code(t)
	tmp = 0.0;
	if ((t <= -0.75) || ~((t <= 0.82)))
		tmp = 1.0 + (-0.16666666666666666 + ((((0.037037037037037035 + (0.04938271604938271 / t)) / t) - 0.2222222222222222) / t));
	else
		tmp = 1.0 + (1.0 / ((t * ((-4.0 / (-1.0 - t)) - 4.0)) - 2.0));
	end
	tmp_2 = tmp;
end
code[t_] := If[Or[LessEqual[t, -0.75], N[Not[LessEqual[t, 0.82]], $MachinePrecision]], N[(1.0 + N[(-0.16666666666666666 + N[(N[(N[(N[(0.037037037037037035 + N[(0.04938271604938271 / t), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision] - 0.2222222222222222), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 + N[(1.0 / N[(N[(t * N[(N[(-4.0 / N[(-1.0 - t), $MachinePrecision]), $MachinePrecision] - 4.0), $MachinePrecision]), $MachinePrecision] - 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.75 \lor \neg \left(t \leq 0.82\right):\\
\;\;\;\;1 + \left(-0.16666666666666666 + \frac{\frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{t} - 0.2222222222222222}{t}\right)\\

\mathbf{else}:\\
\;\;\;\;1 + \frac{1}{t \cdot \left(\frac{-4}{-1 - t} - 4\right) - 2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < -0.75 or 0.819999999999999951 < 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. Step-by-step derivation
      1. sub-neg100.0%

        \[\leadsto \color{blue}{1 + \left(-\frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}\right)} \]
      2. distribute-neg-frac100.0%

        \[\leadsto 1 + \color{blue}{\frac{-1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}} \]
      3. metadata-eval100.0%

        \[\leadsto 1 + \frac{\color{blue}{-1}}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
      4. +-commutative100.0%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) + 2}} \]
      5. fma-define100.0%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\mathsf{fma}\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2\right)}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{-1}{\mathsf{fma}\left(2 - \frac{-2}{-1 - t}, 2 - \frac{-2}{-1 - t}, 2\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in t around -inf 99.4%

      \[\leadsto 1 + \color{blue}{\left(-1 \cdot \frac{0.2222222222222222 + -1 \cdot \frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}}{t} - 0.16666666666666666\right)} \]
    6. Step-by-step derivation
      1. sub-neg99.4%

        \[\leadsto 1 + \color{blue}{\left(-1 \cdot \frac{0.2222222222222222 + -1 \cdot \frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}}{t} + \left(-0.16666666666666666\right)\right)} \]
      2. +-commutative99.4%

        \[\leadsto 1 + \color{blue}{\left(\left(-0.16666666666666666\right) + -1 \cdot \frac{0.2222222222222222 + -1 \cdot \frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}}{t}\right)} \]
      3. mul-1-neg99.4%

        \[\leadsto 1 + \left(\left(-0.16666666666666666\right) + \color{blue}{\left(-\frac{0.2222222222222222 + -1 \cdot \frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}}{t}\right)}\right) \]
      4. unsub-neg99.4%

        \[\leadsto 1 + \color{blue}{\left(\left(-0.16666666666666666\right) - \frac{0.2222222222222222 + -1 \cdot \frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}}{t}\right)} \]
      5. metadata-eval99.4%

        \[\leadsto 1 + \left(\color{blue}{-0.16666666666666666} - \frac{0.2222222222222222 + -1 \cdot \frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}}{t}\right) \]
      6. mul-1-neg99.4%

        \[\leadsto 1 + \left(-0.16666666666666666 - \frac{0.2222222222222222 + \color{blue}{\left(-\frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}\right)}}{t}\right) \]
      7. unsub-neg99.4%

        \[\leadsto 1 + \left(-0.16666666666666666 - \frac{\color{blue}{0.2222222222222222 - \frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}}}{t}\right) \]
      8. associate-*r/99.4%

        \[\leadsto 1 + \left(-0.16666666666666666 - \frac{0.2222222222222222 - \frac{0.037037037037037035 + \color{blue}{\frac{0.04938271604938271 \cdot 1}{t}}}{t}}{t}\right) \]
      9. metadata-eval99.4%

        \[\leadsto 1 + \left(-0.16666666666666666 - \frac{0.2222222222222222 - \frac{0.037037037037037035 + \frac{\color{blue}{0.04938271604938271}}{t}}{t}}{t}\right) \]
    7. Simplified99.4%

      \[\leadsto 1 + \color{blue}{\left(-0.16666666666666666 - \frac{0.2222222222222222 - \frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{t}}{t}\right)} \]

    if -0.75 < t < 0.819999999999999951

    1. Initial program 99.2%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. div-inv99.2%

        \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\color{blue}{2 \cdot \frac{1}{t}}}{1 + \frac{1}{t}}\right)} \]
      2. associate-/l*99.2%

        \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \color{blue}{2 \cdot \frac{\frac{1}{t}}{1 + \frac{1}{t}}}\right)} \]
    4. Applied egg-rr99.2%

      \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \color{blue}{2 \cdot \frac{\frac{1}{t}}{1 + \frac{1}{t}}}\right)} \]
    5. Step-by-step derivation
      1. associate-/r*99.2%

        \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - 2 \cdot \color{blue}{\frac{1}{t \cdot \left(1 + \frac{1}{t}\right)}}\right)} \]
      2. associate-*r/99.2%

        \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \color{blue}{\frac{2 \cdot 1}{t \cdot \left(1 + \frac{1}{t}\right)}}\right)} \]
      3. metadata-eval99.2%

        \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\color{blue}{2}}{t \cdot \left(1 + \frac{1}{t}\right)}\right)} \]
      4. distribute-rgt-in99.2%

        \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{2}{\color{blue}{1 \cdot t + \frac{1}{t} \cdot t}}\right)} \]
      5. lft-mult-inverse99.2%

        \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{2}{1 \cdot t + \color{blue}{1}}\right)} \]
      6. *-lft-identity99.2%

        \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{2}{\color{blue}{t} + 1}\right)} \]
    6. Simplified99.2%

      \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \color{blue}{\frac{2}{t + 1}}\right)} \]
    7. Taylor expanded in t around 0 98.6%

      \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \color{blue}{\left(2 \cdot t\right)}} \]
    8. Step-by-step derivation
      1. *-commutative98.6%

        \[\leadsto 1 - \frac{1}{2 + \color{blue}{\left(2 \cdot t\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}} \]
      2. sub-neg98.6%

        \[\leadsto 1 - \frac{1}{2 + \left(2 \cdot t\right) \cdot \color{blue}{\left(2 + \left(-\frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)\right)}} \]
      3. distribute-lft-in98.6%

        \[\leadsto 1 - \frac{1}{2 + \color{blue}{\left(\left(2 \cdot t\right) \cdot 2 + \left(2 \cdot t\right) \cdot \left(-\frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)\right)}} \]
      4. *-commutative98.6%

        \[\leadsto 1 - \frac{1}{2 + \left(\color{blue}{\left(t \cdot 2\right)} \cdot 2 + \left(2 \cdot t\right) \cdot \left(-\frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)\right)} \]
      5. *-commutative98.6%

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

        \[\leadsto 1 - \frac{1}{2 + \left(\left(t \cdot 2\right) \cdot 2 + \left(t \cdot 2\right) \cdot \left(-\color{blue}{\frac{2}{t \cdot \left(1 + \frac{1}{t}\right)}}\right)\right)} \]
      7. distribute-neg-frac99.4%

        \[\leadsto 1 - \frac{1}{2 + \left(\left(t \cdot 2\right) \cdot 2 + \left(t \cdot 2\right) \cdot \color{blue}{\frac{-2}{t \cdot \left(1 + \frac{1}{t}\right)}}\right)} \]
      8. metadata-eval99.4%

        \[\leadsto 1 - \frac{1}{2 + \left(\left(t \cdot 2\right) \cdot 2 + \left(t \cdot 2\right) \cdot \frac{\color{blue}{-2}}{t \cdot \left(1 + \frac{1}{t}\right)}\right)} \]
      9. distribute-rgt-in99.4%

        \[\leadsto 1 - \frac{1}{2 + \left(\left(t \cdot 2\right) \cdot 2 + \left(t \cdot 2\right) \cdot \frac{-2}{\color{blue}{1 \cdot t + \frac{1}{t} \cdot t}}\right)} \]
      10. *-un-lft-identity99.4%

        \[\leadsto 1 - \frac{1}{2 + \left(\left(t \cdot 2\right) \cdot 2 + \left(t \cdot 2\right) \cdot \frac{-2}{\color{blue}{t} + \frac{1}{t} \cdot t}\right)} \]
      11. lft-mult-inverse99.4%

        \[\leadsto 1 - \frac{1}{2 + \left(\left(t \cdot 2\right) \cdot 2 + \left(t \cdot 2\right) \cdot \frac{-2}{t + \color{blue}{1}}\right)} \]
    9. Applied egg-rr99.4%

      \[\leadsto 1 - \frac{1}{2 + \color{blue}{\left(\left(t \cdot 2\right) \cdot 2 + \left(t \cdot 2\right) \cdot \frac{-2}{t + 1}\right)}} \]
    10. Step-by-step derivation
      1. associate-*l*99.4%

        \[\leadsto 1 - \frac{1}{2 + \left(\color{blue}{t \cdot \left(2 \cdot 2\right)} + \left(t \cdot 2\right) \cdot \frac{-2}{t + 1}\right)} \]
      2. metadata-eval99.4%

        \[\leadsto 1 - \frac{1}{2 + \left(t \cdot \color{blue}{4} + \left(t \cdot 2\right) \cdot \frac{-2}{t + 1}\right)} \]
      3. associate-*l*99.4%

        \[\leadsto 1 - \frac{1}{2 + \left(t \cdot 4 + \color{blue}{t \cdot \left(2 \cdot \frac{-2}{t + 1}\right)}\right)} \]
      4. distribute-lft-out99.4%

        \[\leadsto 1 - \frac{1}{2 + \color{blue}{t \cdot \left(4 + 2 \cdot \frac{-2}{t + 1}\right)}} \]
      5. associate-*r/99.4%

        \[\leadsto 1 - \frac{1}{2 + t \cdot \left(4 + \color{blue}{\frac{2 \cdot -2}{t + 1}}\right)} \]
      6. metadata-eval99.4%

        \[\leadsto 1 - \frac{1}{2 + t \cdot \left(4 + \frac{\color{blue}{-4}}{t + 1}\right)} \]
      7. +-commutative99.4%

        \[\leadsto 1 - \frac{1}{2 + t \cdot \left(4 + \frac{-4}{\color{blue}{1 + t}}\right)} \]
    11. Simplified99.4%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -0.75 \lor \neg \left(t \leq 0.82\right):\\ \;\;\;\;1 + \left(-0.16666666666666666 + \frac{\frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{t} - 0.2222222222222222}{t}\right)\\ \mathbf{else}:\\ \;\;\;\;1 + \frac{1}{t \cdot \left(\frac{-4}{-1 - t} - 4\right) - 2}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 99.2% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq -0.33 \lor \neg \left(t \leq 0.68\right):\\ \;\;\;\;1 + \left(-0.16666666666666666 + \frac{\frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{t} - 0.2222222222222222}{t}\right)\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (or (<= t -0.33) (not (<= t 0.68)))
   (+
    1.0
    (+
     -0.16666666666666666
     (/
      (-
       (/ (+ 0.037037037037037035 (/ 0.04938271604938271 t)) t)
       0.2222222222222222)
      t)))
   0.5))
double code(double t) {
	double tmp;
	if ((t <= -0.33) || !(t <= 0.68)) {
		tmp = 1.0 + (-0.16666666666666666 + ((((0.037037037037037035 + (0.04938271604938271 / t)) / t) - 0.2222222222222222) / t));
	} else {
		tmp = 0.5;
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: tmp
    if ((t <= (-0.33d0)) .or. (.not. (t <= 0.68d0))) then
        tmp = 1.0d0 + ((-0.16666666666666666d0) + ((((0.037037037037037035d0 + (0.04938271604938271d0 / t)) / t) - 0.2222222222222222d0) / t))
    else
        tmp = 0.5d0
    end if
    code = tmp
end function
public static double code(double t) {
	double tmp;
	if ((t <= -0.33) || !(t <= 0.68)) {
		tmp = 1.0 + (-0.16666666666666666 + ((((0.037037037037037035 + (0.04938271604938271 / t)) / t) - 0.2222222222222222) / t));
	} else {
		tmp = 0.5;
	}
	return tmp;
}
def code(t):
	tmp = 0
	if (t <= -0.33) or not (t <= 0.68):
		tmp = 1.0 + (-0.16666666666666666 + ((((0.037037037037037035 + (0.04938271604938271 / t)) / t) - 0.2222222222222222) / t))
	else:
		tmp = 0.5
	return tmp
function code(t)
	tmp = 0.0
	if ((t <= -0.33) || !(t <= 0.68))
		tmp = Float64(1.0 + Float64(-0.16666666666666666 + Float64(Float64(Float64(Float64(0.037037037037037035 + Float64(0.04938271604938271 / t)) / t) - 0.2222222222222222) / t)));
	else
		tmp = 0.5;
	end
	return tmp
end
function tmp_2 = code(t)
	tmp = 0.0;
	if ((t <= -0.33) || ~((t <= 0.68)))
		tmp = 1.0 + (-0.16666666666666666 + ((((0.037037037037037035 + (0.04938271604938271 / t)) / t) - 0.2222222222222222) / t));
	else
		tmp = 0.5;
	end
	tmp_2 = tmp;
end
code[t_] := If[Or[LessEqual[t, -0.33], N[Not[LessEqual[t, 0.68]], $MachinePrecision]], N[(1.0 + N[(-0.16666666666666666 + N[(N[(N[(N[(0.037037037037037035 + N[(0.04938271604938271 / t), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision] - 0.2222222222222222), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 0.5]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.33 \lor \neg \left(t \leq 0.68\right):\\
\;\;\;\;1 + \left(-0.16666666666666666 + \frac{\frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{t} - 0.2222222222222222}{t}\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < -0.330000000000000016 or 0.680000000000000049 < 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. Step-by-step derivation
      1. sub-neg100.0%

        \[\leadsto \color{blue}{1 + \left(-\frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}\right)} \]
      2. distribute-neg-frac100.0%

        \[\leadsto 1 + \color{blue}{\frac{-1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}} \]
      3. metadata-eval100.0%

        \[\leadsto 1 + \frac{\color{blue}{-1}}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
      4. +-commutative100.0%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) + 2}} \]
      5. fma-define100.0%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\mathsf{fma}\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2\right)}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{-1}{\mathsf{fma}\left(2 - \frac{-2}{-1 - t}, 2 - \frac{-2}{-1 - t}, 2\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in t around -inf 99.4%

      \[\leadsto 1 + \color{blue}{\left(-1 \cdot \frac{0.2222222222222222 + -1 \cdot \frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}}{t} - 0.16666666666666666\right)} \]
    6. Step-by-step derivation
      1. sub-neg99.4%

        \[\leadsto 1 + \color{blue}{\left(-1 \cdot \frac{0.2222222222222222 + -1 \cdot \frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}}{t} + \left(-0.16666666666666666\right)\right)} \]
      2. +-commutative99.4%

        \[\leadsto 1 + \color{blue}{\left(\left(-0.16666666666666666\right) + -1 \cdot \frac{0.2222222222222222 + -1 \cdot \frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}}{t}\right)} \]
      3. mul-1-neg99.4%

        \[\leadsto 1 + \left(\left(-0.16666666666666666\right) + \color{blue}{\left(-\frac{0.2222222222222222 + -1 \cdot \frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}}{t}\right)}\right) \]
      4. unsub-neg99.4%

        \[\leadsto 1 + \color{blue}{\left(\left(-0.16666666666666666\right) - \frac{0.2222222222222222 + -1 \cdot \frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}}{t}\right)} \]
      5. metadata-eval99.4%

        \[\leadsto 1 + \left(\color{blue}{-0.16666666666666666} - \frac{0.2222222222222222 + -1 \cdot \frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}}{t}\right) \]
      6. mul-1-neg99.4%

        \[\leadsto 1 + \left(-0.16666666666666666 - \frac{0.2222222222222222 + \color{blue}{\left(-\frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}\right)}}{t}\right) \]
      7. unsub-neg99.4%

        \[\leadsto 1 + \left(-0.16666666666666666 - \frac{\color{blue}{0.2222222222222222 - \frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}}}{t}\right) \]
      8. associate-*r/99.4%

        \[\leadsto 1 + \left(-0.16666666666666666 - \frac{0.2222222222222222 - \frac{0.037037037037037035 + \color{blue}{\frac{0.04938271604938271 \cdot 1}{t}}}{t}}{t}\right) \]
      9. metadata-eval99.4%

        \[\leadsto 1 + \left(-0.16666666666666666 - \frac{0.2222222222222222 - \frac{0.037037037037037035 + \frac{\color{blue}{0.04938271604938271}}{t}}{t}}{t}\right) \]
    7. Simplified99.4%

      \[\leadsto 1 + \color{blue}{\left(-0.16666666666666666 - \frac{0.2222222222222222 - \frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{t}}{t}\right)} \]

    if -0.330000000000000016 < t < 0.680000000000000049

    1. Initial program 99.2%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Step-by-step derivation
      1. sub-neg99.2%

        \[\leadsto \color{blue}{1 + \left(-\frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}\right)} \]
      2. distribute-neg-frac99.2%

        \[\leadsto 1 + \color{blue}{\frac{-1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}} \]
      3. metadata-eval99.2%

        \[\leadsto 1 + \frac{\color{blue}{-1}}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
      4. +-commutative99.2%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) + 2}} \]
      5. fma-define99.2%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\mathsf{fma}\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2\right)}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{-1}{\mathsf{fma}\left(2 - \frac{-2}{-1 - t}, 2 - \frac{-2}{-1 - t}, 2\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in t around 0 98.8%

      \[\leadsto \color{blue}{0.5} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -0.33 \lor \neg \left(t \leq 0.68\right):\\ \;\;\;\;1 + \left(-0.16666666666666666 + \frac{\frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{t} - 0.2222222222222222}{t}\right)\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 100.0% accurate, 1.2× speedup?

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

\\
1 + \frac{1}{\left(2 + \frac{2}{-1 - t}\right) \cdot \left(\frac{\frac{2}{t}}{1 + \frac{1}{t}} - 2\right) - 2}
\end{array}
Derivation
  1. Initial program 99.6%

    \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. div-inv99.6%

      \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\color{blue}{2 \cdot \frac{1}{t}}}{1 + \frac{1}{t}}\right)} \]
    2. associate-/l*99.6%

      \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \color{blue}{2 \cdot \frac{\frac{1}{t}}{1 + \frac{1}{t}}}\right)} \]
  4. Applied egg-rr99.6%

    \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \color{blue}{2 \cdot \frac{\frac{1}{t}}{1 + \frac{1}{t}}}\right)} \]
  5. Step-by-step derivation
    1. associate-/r*99.6%

      \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - 2 \cdot \color{blue}{\frac{1}{t \cdot \left(1 + \frac{1}{t}\right)}}\right)} \]
    2. associate-*r/99.6%

      \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \color{blue}{\frac{2 \cdot 1}{t \cdot \left(1 + \frac{1}{t}\right)}}\right)} \]
    3. metadata-eval99.6%

      \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\color{blue}{2}}{t \cdot \left(1 + \frac{1}{t}\right)}\right)} \]
    4. distribute-rgt-in99.6%

      \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{2}{\color{blue}{1 \cdot t + \frac{1}{t} \cdot t}}\right)} \]
    5. lft-mult-inverse99.6%

      \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{2}{1 \cdot t + \color{blue}{1}}\right)} \]
    6. *-lft-identity99.6%

      \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{2}{\color{blue}{t} + 1}\right)} \]
  6. Simplified99.6%

    \[\leadsto 1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \color{blue}{\frac{2}{t + 1}}\right)} \]
  7. Final simplification99.6%

    \[\leadsto 1 + \frac{1}{\left(2 + \frac{2}{-1 - t}\right) \cdot \left(\frac{\frac{2}{t}}{1 + \frac{1}{t}} - 2\right) - 2} \]
  8. Add Preprocessing

Alternative 5: 99.2% accurate, 1.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq -0.33 \lor \neg \left(t \leq 0.68\right):\\ \;\;\;\;0.8333333333333334 + \frac{\frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{t} - 0.2222222222222222}{t}\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (or (<= t -0.33) (not (<= t 0.68)))
   (+
    0.8333333333333334
    (/
     (-
      (/ (+ 0.037037037037037035 (/ 0.04938271604938271 t)) t)
      0.2222222222222222)
     t))
   0.5))
double code(double t) {
	double tmp;
	if ((t <= -0.33) || !(t <= 0.68)) {
		tmp = 0.8333333333333334 + ((((0.037037037037037035 + (0.04938271604938271 / t)) / t) - 0.2222222222222222) / t);
	} else {
		tmp = 0.5;
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: tmp
    if ((t <= (-0.33d0)) .or. (.not. (t <= 0.68d0))) then
        tmp = 0.8333333333333334d0 + ((((0.037037037037037035d0 + (0.04938271604938271d0 / t)) / t) - 0.2222222222222222d0) / t)
    else
        tmp = 0.5d0
    end if
    code = tmp
end function
public static double code(double t) {
	double tmp;
	if ((t <= -0.33) || !(t <= 0.68)) {
		tmp = 0.8333333333333334 + ((((0.037037037037037035 + (0.04938271604938271 / t)) / t) - 0.2222222222222222) / t);
	} else {
		tmp = 0.5;
	}
	return tmp;
}
def code(t):
	tmp = 0
	if (t <= -0.33) or not (t <= 0.68):
		tmp = 0.8333333333333334 + ((((0.037037037037037035 + (0.04938271604938271 / t)) / t) - 0.2222222222222222) / t)
	else:
		tmp = 0.5
	return tmp
function code(t)
	tmp = 0.0
	if ((t <= -0.33) || !(t <= 0.68))
		tmp = Float64(0.8333333333333334 + Float64(Float64(Float64(Float64(0.037037037037037035 + Float64(0.04938271604938271 / t)) / t) - 0.2222222222222222) / t));
	else
		tmp = 0.5;
	end
	return tmp
end
function tmp_2 = code(t)
	tmp = 0.0;
	if ((t <= -0.33) || ~((t <= 0.68)))
		tmp = 0.8333333333333334 + ((((0.037037037037037035 + (0.04938271604938271 / t)) / t) - 0.2222222222222222) / t);
	else
		tmp = 0.5;
	end
	tmp_2 = tmp;
end
code[t_] := If[Or[LessEqual[t, -0.33], N[Not[LessEqual[t, 0.68]], $MachinePrecision]], N[(0.8333333333333334 + N[(N[(N[(N[(0.037037037037037035 + N[(0.04938271604938271 / t), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision] - 0.2222222222222222), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision], 0.5]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.33 \lor \neg \left(t \leq 0.68\right):\\
\;\;\;\;0.8333333333333334 + \frac{\frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{t} - 0.2222222222222222}{t}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < -0.330000000000000016 or 0.680000000000000049 < 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. Step-by-step derivation
      1. sub-neg100.0%

        \[\leadsto \color{blue}{1 + \left(-\frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}\right)} \]
      2. distribute-neg-frac100.0%

        \[\leadsto 1 + \color{blue}{\frac{-1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}} \]
      3. metadata-eval100.0%

        \[\leadsto 1 + \frac{\color{blue}{-1}}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
      4. +-commutative100.0%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) + 2}} \]
      5. fma-define100.0%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\mathsf{fma}\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2\right)}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{-1}{\mathsf{fma}\left(2 - \frac{-2}{-1 - t}, 2 - \frac{-2}{-1 - t}, 2\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in t around -inf 99.4%

      \[\leadsto \color{blue}{0.8333333333333334 + -1 \cdot \frac{0.2222222222222222 + -1 \cdot \frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}}{t}} \]
    6. Step-by-step derivation
      1. mul-1-neg99.4%

        \[\leadsto 0.8333333333333334 + \color{blue}{\left(-\frac{0.2222222222222222 + -1 \cdot \frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}}{t}\right)} \]
      2. unsub-neg99.4%

        \[\leadsto \color{blue}{0.8333333333333334 - \frac{0.2222222222222222 + -1 \cdot \frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}}{t}} \]
      3. mul-1-neg99.4%

        \[\leadsto 0.8333333333333334 - \frac{0.2222222222222222 + \color{blue}{\left(-\frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}\right)}}{t} \]
      4. unsub-neg99.4%

        \[\leadsto 0.8333333333333334 - \frac{\color{blue}{0.2222222222222222 - \frac{0.037037037037037035 + 0.04938271604938271 \cdot \frac{1}{t}}{t}}}{t} \]
      5. associate-*r/99.4%

        \[\leadsto 0.8333333333333334 - \frac{0.2222222222222222 - \frac{0.037037037037037035 + \color{blue}{\frac{0.04938271604938271 \cdot 1}{t}}}{t}}{t} \]
      6. metadata-eval99.4%

        \[\leadsto 0.8333333333333334 - \frac{0.2222222222222222 - \frac{0.037037037037037035 + \frac{\color{blue}{0.04938271604938271}}{t}}{t}}{t} \]
    7. Simplified99.4%

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

    if -0.330000000000000016 < t < 0.680000000000000049

    1. Initial program 99.2%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Step-by-step derivation
      1. sub-neg99.2%

        \[\leadsto \color{blue}{1 + \left(-\frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}\right)} \]
      2. distribute-neg-frac99.2%

        \[\leadsto 1 + \color{blue}{\frac{-1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}} \]
      3. metadata-eval99.2%

        \[\leadsto 1 + \frac{\color{blue}{-1}}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
      4. +-commutative99.2%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) + 2}} \]
      5. fma-define99.2%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\mathsf{fma}\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2\right)}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{-1}{\mathsf{fma}\left(2 - \frac{-2}{-1 - t}, 2 - \frac{-2}{-1 - t}, 2\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in t around 0 98.8%

      \[\leadsto \color{blue}{0.5} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -0.33 \lor \neg \left(t \leq 0.68\right):\\ \;\;\;\;0.8333333333333334 + \frac{\frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{t} - 0.2222222222222222}{t}\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 99.2% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq -0.52 \lor \neg \left(t \leq 0.23\right):\\ \;\;\;\;1 + \left(-0.16666666666666666 - \frac{0.2222222222222222 + \frac{-0.037037037037037035}{t}}{t}\right)\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (or (<= t -0.52) (not (<= t 0.23)))
   (+
    1.0
    (-
     -0.16666666666666666
     (/ (+ 0.2222222222222222 (/ -0.037037037037037035 t)) t)))
   0.5))
double code(double t) {
	double tmp;
	if ((t <= -0.52) || !(t <= 0.23)) {
		tmp = 1.0 + (-0.16666666666666666 - ((0.2222222222222222 + (-0.037037037037037035 / t)) / t));
	} else {
		tmp = 0.5;
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: tmp
    if ((t <= (-0.52d0)) .or. (.not. (t <= 0.23d0))) then
        tmp = 1.0d0 + ((-0.16666666666666666d0) - ((0.2222222222222222d0 + ((-0.037037037037037035d0) / t)) / t))
    else
        tmp = 0.5d0
    end if
    code = tmp
end function
public static double code(double t) {
	double tmp;
	if ((t <= -0.52) || !(t <= 0.23)) {
		tmp = 1.0 + (-0.16666666666666666 - ((0.2222222222222222 + (-0.037037037037037035 / t)) / t));
	} else {
		tmp = 0.5;
	}
	return tmp;
}
def code(t):
	tmp = 0
	if (t <= -0.52) or not (t <= 0.23):
		tmp = 1.0 + (-0.16666666666666666 - ((0.2222222222222222 + (-0.037037037037037035 / t)) / t))
	else:
		tmp = 0.5
	return tmp
function code(t)
	tmp = 0.0
	if ((t <= -0.52) || !(t <= 0.23))
		tmp = Float64(1.0 + Float64(-0.16666666666666666 - Float64(Float64(0.2222222222222222 + Float64(-0.037037037037037035 / t)) / t)));
	else
		tmp = 0.5;
	end
	return tmp
end
function tmp_2 = code(t)
	tmp = 0.0;
	if ((t <= -0.52) || ~((t <= 0.23)))
		tmp = 1.0 + (-0.16666666666666666 - ((0.2222222222222222 + (-0.037037037037037035 / t)) / t));
	else
		tmp = 0.5;
	end
	tmp_2 = tmp;
end
code[t_] := If[Or[LessEqual[t, -0.52], N[Not[LessEqual[t, 0.23]], $MachinePrecision]], N[(1.0 + N[(-0.16666666666666666 - N[(N[(0.2222222222222222 + N[(-0.037037037037037035 / t), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 0.5]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.52 \lor \neg \left(t \leq 0.23\right):\\
\;\;\;\;1 + \left(-0.16666666666666666 - \frac{0.2222222222222222 + \frac{-0.037037037037037035}{t}}{t}\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < -0.52000000000000002 or 0.23000000000000001 < 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. Step-by-step derivation
      1. sub-neg100.0%

        \[\leadsto \color{blue}{1 + \left(-\frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}\right)} \]
      2. distribute-neg-frac100.0%

        \[\leadsto 1 + \color{blue}{\frac{-1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}} \]
      3. metadata-eval100.0%

        \[\leadsto 1 + \frac{\color{blue}{-1}}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
      4. +-commutative100.0%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) + 2}} \]
      5. fma-define100.0%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\mathsf{fma}\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2\right)}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{-1}{\mathsf{fma}\left(2 - \frac{-2}{-1 - t}, 2 - \frac{-2}{-1 - t}, 2\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in t around -inf 99.1%

      \[\leadsto 1 + \color{blue}{\left(-1 \cdot \frac{0.2222222222222222 - 0.037037037037037035 \cdot \frac{1}{t}}{t} - 0.16666666666666666\right)} \]
    6. Step-by-step derivation
      1. sub-neg99.1%

        \[\leadsto 1 + \color{blue}{\left(-1 \cdot \frac{0.2222222222222222 - 0.037037037037037035 \cdot \frac{1}{t}}{t} + \left(-0.16666666666666666\right)\right)} \]
      2. +-commutative99.1%

        \[\leadsto 1 + \color{blue}{\left(\left(-0.16666666666666666\right) + -1 \cdot \frac{0.2222222222222222 - 0.037037037037037035 \cdot \frac{1}{t}}{t}\right)} \]
      3. mul-1-neg99.1%

        \[\leadsto 1 + \left(\left(-0.16666666666666666\right) + \color{blue}{\left(-\frac{0.2222222222222222 - 0.037037037037037035 \cdot \frac{1}{t}}{t}\right)}\right) \]
      4. unsub-neg99.1%

        \[\leadsto 1 + \color{blue}{\left(\left(-0.16666666666666666\right) - \frac{0.2222222222222222 - 0.037037037037037035 \cdot \frac{1}{t}}{t}\right)} \]
      5. metadata-eval99.1%

        \[\leadsto 1 + \left(\color{blue}{-0.16666666666666666} - \frac{0.2222222222222222 - 0.037037037037037035 \cdot \frac{1}{t}}{t}\right) \]
      6. sub-neg99.1%

        \[\leadsto 1 + \left(-0.16666666666666666 - \frac{\color{blue}{0.2222222222222222 + \left(-0.037037037037037035 \cdot \frac{1}{t}\right)}}{t}\right) \]
      7. associate-*r/99.1%

        \[\leadsto 1 + \left(-0.16666666666666666 - \frac{0.2222222222222222 + \left(-\color{blue}{\frac{0.037037037037037035 \cdot 1}{t}}\right)}{t}\right) \]
      8. metadata-eval99.1%

        \[\leadsto 1 + \left(-0.16666666666666666 - \frac{0.2222222222222222 + \left(-\frac{\color{blue}{0.037037037037037035}}{t}\right)}{t}\right) \]
      9. distribute-neg-frac99.1%

        \[\leadsto 1 + \left(-0.16666666666666666 - \frac{0.2222222222222222 + \color{blue}{\frac{-0.037037037037037035}{t}}}{t}\right) \]
      10. metadata-eval99.1%

        \[\leadsto 1 + \left(-0.16666666666666666 - \frac{0.2222222222222222 + \frac{\color{blue}{-0.037037037037037035}}{t}}{t}\right) \]
    7. Simplified99.1%

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

    if -0.52000000000000002 < t < 0.23000000000000001

    1. Initial program 99.2%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Step-by-step derivation
      1. sub-neg99.2%

        \[\leadsto \color{blue}{1 + \left(-\frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}\right)} \]
      2. distribute-neg-frac99.2%

        \[\leadsto 1 + \color{blue}{\frac{-1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}} \]
      3. metadata-eval99.2%

        \[\leadsto 1 + \frac{\color{blue}{-1}}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
      4. +-commutative99.2%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) + 2}} \]
      5. fma-define99.2%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\mathsf{fma}\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2\right)}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{-1}{\mathsf{fma}\left(2 - \frac{-2}{-1 - t}, 2 - \frac{-2}{-1 - t}, 2\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in t around 0 98.8%

      \[\leadsto \color{blue}{0.5} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -0.52 \lor \neg \left(t \leq 0.23\right):\\ \;\;\;\;1 + \left(-0.16666666666666666 - \frac{0.2222222222222222 + \frac{-0.037037037037037035}{t}}{t}\right)\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 99.2% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq -0.52 \lor \neg \left(t \leq 0.23\right):\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222 + \frac{-0.037037037037037035}{t}}{t}\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (or (<= t -0.52) (not (<= t 0.23)))
   (-
    0.8333333333333334
    (/ (+ 0.2222222222222222 (/ -0.037037037037037035 t)) t))
   0.5))
double code(double t) {
	double tmp;
	if ((t <= -0.52) || !(t <= 0.23)) {
		tmp = 0.8333333333333334 - ((0.2222222222222222 + (-0.037037037037037035 / t)) / t);
	} else {
		tmp = 0.5;
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: tmp
    if ((t <= (-0.52d0)) .or. (.not. (t <= 0.23d0))) then
        tmp = 0.8333333333333334d0 - ((0.2222222222222222d0 + ((-0.037037037037037035d0) / t)) / t)
    else
        tmp = 0.5d0
    end if
    code = tmp
end function
public static double code(double t) {
	double tmp;
	if ((t <= -0.52) || !(t <= 0.23)) {
		tmp = 0.8333333333333334 - ((0.2222222222222222 + (-0.037037037037037035 / t)) / t);
	} else {
		tmp = 0.5;
	}
	return tmp;
}
def code(t):
	tmp = 0
	if (t <= -0.52) or not (t <= 0.23):
		tmp = 0.8333333333333334 - ((0.2222222222222222 + (-0.037037037037037035 / t)) / t)
	else:
		tmp = 0.5
	return tmp
function code(t)
	tmp = 0.0
	if ((t <= -0.52) || !(t <= 0.23))
		tmp = Float64(0.8333333333333334 - Float64(Float64(0.2222222222222222 + Float64(-0.037037037037037035 / t)) / t));
	else
		tmp = 0.5;
	end
	return tmp
end
function tmp_2 = code(t)
	tmp = 0.0;
	if ((t <= -0.52) || ~((t <= 0.23)))
		tmp = 0.8333333333333334 - ((0.2222222222222222 + (-0.037037037037037035 / t)) / t);
	else
		tmp = 0.5;
	end
	tmp_2 = tmp;
end
code[t_] := If[Or[LessEqual[t, -0.52], N[Not[LessEqual[t, 0.23]], $MachinePrecision]], N[(0.8333333333333334 - N[(N[(0.2222222222222222 + N[(-0.037037037037037035 / t), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision], 0.5]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.52 \lor \neg \left(t \leq 0.23\right):\\
\;\;\;\;0.8333333333333334 - \frac{0.2222222222222222 + \frac{-0.037037037037037035}{t}}{t}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < -0.52000000000000002 or 0.23000000000000001 < 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. Step-by-step derivation
      1. sub-neg100.0%

        \[\leadsto \color{blue}{1 + \left(-\frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}\right)} \]
      2. distribute-neg-frac100.0%

        \[\leadsto 1 + \color{blue}{\frac{-1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}} \]
      3. metadata-eval100.0%

        \[\leadsto 1 + \frac{\color{blue}{-1}}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
      4. +-commutative100.0%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) + 2}} \]
      5. fma-define100.0%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\mathsf{fma}\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2\right)}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{-1}{\mathsf{fma}\left(2 - \frac{-2}{-1 - t}, 2 - \frac{-2}{-1 - t}, 2\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in t around -inf 99.1%

      \[\leadsto \color{blue}{0.8333333333333334 + -1 \cdot \frac{0.2222222222222222 - 0.037037037037037035 \cdot \frac{1}{t}}{t}} \]
    6. Step-by-step derivation
      1. mul-1-neg99.1%

        \[\leadsto 0.8333333333333334 + \color{blue}{\left(-\frac{0.2222222222222222 - 0.037037037037037035 \cdot \frac{1}{t}}{t}\right)} \]
      2. unsub-neg99.1%

        \[\leadsto \color{blue}{0.8333333333333334 - \frac{0.2222222222222222 - 0.037037037037037035 \cdot \frac{1}{t}}{t}} \]
      3. sub-neg99.1%

        \[\leadsto 0.8333333333333334 - \frac{\color{blue}{0.2222222222222222 + \left(-0.037037037037037035 \cdot \frac{1}{t}\right)}}{t} \]
      4. associate-*r/99.1%

        \[\leadsto 0.8333333333333334 - \frac{0.2222222222222222 + \left(-\color{blue}{\frac{0.037037037037037035 \cdot 1}{t}}\right)}{t} \]
      5. metadata-eval99.1%

        \[\leadsto 0.8333333333333334 - \frac{0.2222222222222222 + \left(-\frac{\color{blue}{0.037037037037037035}}{t}\right)}{t} \]
      6. distribute-neg-frac99.1%

        \[\leadsto 0.8333333333333334 - \frac{0.2222222222222222 + \color{blue}{\frac{-0.037037037037037035}{t}}}{t} \]
      7. metadata-eval99.1%

        \[\leadsto 0.8333333333333334 - \frac{0.2222222222222222 + \frac{\color{blue}{-0.037037037037037035}}{t}}{t} \]
    7. Simplified99.1%

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

    if -0.52000000000000002 < t < 0.23000000000000001

    1. Initial program 99.2%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Step-by-step derivation
      1. sub-neg99.2%

        \[\leadsto \color{blue}{1 + \left(-\frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}\right)} \]
      2. distribute-neg-frac99.2%

        \[\leadsto 1 + \color{blue}{\frac{-1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}} \]
      3. metadata-eval99.2%

        \[\leadsto 1 + \frac{\color{blue}{-1}}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
      4. +-commutative99.2%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) + 2}} \]
      5. fma-define99.2%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\mathsf{fma}\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2\right)}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{-1}{\mathsf{fma}\left(2 - \frac{-2}{-1 - t}, 2 - \frac{-2}{-1 - t}, 2\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in t around 0 98.8%

      \[\leadsto \color{blue}{0.5} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -0.52 \lor \neg \left(t \leq 0.23\right):\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222 + \frac{-0.037037037037037035}{t}}{t}\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \]
  5. Add Preprocessing

Alternative 8: 99.0% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq -0.49 \lor \neg \left(t \leq 0.65\right):\\ \;\;\;\;1 + \left(-0.16666666666666666 + \frac{-0.2222222222222222}{t}\right)\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (or (<= t -0.49) (not (<= t 0.65)))
   (+ 1.0 (+ -0.16666666666666666 (/ -0.2222222222222222 t)))
   0.5))
double code(double t) {
	double tmp;
	if ((t <= -0.49) || !(t <= 0.65)) {
		tmp = 1.0 + (-0.16666666666666666 + (-0.2222222222222222 / t));
	} else {
		tmp = 0.5;
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: tmp
    if ((t <= (-0.49d0)) .or. (.not. (t <= 0.65d0))) then
        tmp = 1.0d0 + ((-0.16666666666666666d0) + ((-0.2222222222222222d0) / t))
    else
        tmp = 0.5d0
    end if
    code = tmp
end function
public static double code(double t) {
	double tmp;
	if ((t <= -0.49) || !(t <= 0.65)) {
		tmp = 1.0 + (-0.16666666666666666 + (-0.2222222222222222 / t));
	} else {
		tmp = 0.5;
	}
	return tmp;
}
def code(t):
	tmp = 0
	if (t <= -0.49) or not (t <= 0.65):
		tmp = 1.0 + (-0.16666666666666666 + (-0.2222222222222222 / t))
	else:
		tmp = 0.5
	return tmp
function code(t)
	tmp = 0.0
	if ((t <= -0.49) || !(t <= 0.65))
		tmp = Float64(1.0 + Float64(-0.16666666666666666 + Float64(-0.2222222222222222 / t)));
	else
		tmp = 0.5;
	end
	return tmp
end
function tmp_2 = code(t)
	tmp = 0.0;
	if ((t <= -0.49) || ~((t <= 0.65)))
		tmp = 1.0 + (-0.16666666666666666 + (-0.2222222222222222 / t));
	else
		tmp = 0.5;
	end
	tmp_2 = tmp;
end
code[t_] := If[Or[LessEqual[t, -0.49], N[Not[LessEqual[t, 0.65]], $MachinePrecision]], N[(1.0 + N[(-0.16666666666666666 + N[(-0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 0.5]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.49 \lor \neg \left(t \leq 0.65\right):\\
\;\;\;\;1 + \left(-0.16666666666666666 + \frac{-0.2222222222222222}{t}\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < -0.48999999999999999 or 0.650000000000000022 < 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. Step-by-step derivation
      1. sub-neg100.0%

        \[\leadsto \color{blue}{1 + \left(-\frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}\right)} \]
      2. distribute-neg-frac100.0%

        \[\leadsto 1 + \color{blue}{\frac{-1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}} \]
      3. metadata-eval100.0%

        \[\leadsto 1 + \frac{\color{blue}{-1}}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
      4. +-commutative100.0%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) + 2}} \]
      5. fma-define100.0%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\mathsf{fma}\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2\right)}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{-1}{\mathsf{fma}\left(2 - \frac{-2}{-1 - t}, 2 - \frac{-2}{-1 - t}, 2\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in t around inf 98.8%

      \[\leadsto 1 + \color{blue}{-1 \cdot \left(0.16666666666666666 + 0.2222222222222222 \cdot \frac{1}{t}\right)} \]
    6. Step-by-step derivation
      1. distribute-lft-in98.8%

        \[\leadsto 1 + \color{blue}{\left(-1 \cdot 0.16666666666666666 + -1 \cdot \left(0.2222222222222222 \cdot \frac{1}{t}\right)\right)} \]
      2. metadata-eval98.8%

        \[\leadsto 1 + \left(\color{blue}{-0.16666666666666666} + -1 \cdot \left(0.2222222222222222 \cdot \frac{1}{t}\right)\right) \]
      3. associate-*r/98.8%

        \[\leadsto 1 + \left(-0.16666666666666666 + -1 \cdot \color{blue}{\frac{0.2222222222222222 \cdot 1}{t}}\right) \]
      4. metadata-eval98.8%

        \[\leadsto 1 + \left(-0.16666666666666666 + -1 \cdot \frac{\color{blue}{0.2222222222222222}}{t}\right) \]
      5. associate-*r/98.8%

        \[\leadsto 1 + \left(-0.16666666666666666 + \color{blue}{\frac{-1 \cdot 0.2222222222222222}{t}}\right) \]
      6. metadata-eval98.8%

        \[\leadsto 1 + \left(-0.16666666666666666 + \frac{\color{blue}{-0.2222222222222222}}{t}\right) \]
    7. Simplified98.8%

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

    if -0.48999999999999999 < t < 0.650000000000000022

    1. Initial program 99.2%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Step-by-step derivation
      1. sub-neg99.2%

        \[\leadsto \color{blue}{1 + \left(-\frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}\right)} \]
      2. distribute-neg-frac99.2%

        \[\leadsto 1 + \color{blue}{\frac{-1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}} \]
      3. metadata-eval99.2%

        \[\leadsto 1 + \frac{\color{blue}{-1}}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
      4. +-commutative99.2%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) + 2}} \]
      5. fma-define99.2%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\mathsf{fma}\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2\right)}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{-1}{\mathsf{fma}\left(2 - \frac{-2}{-1 - t}, 2 - \frac{-2}{-1 - t}, 2\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in t around 0 98.8%

      \[\leadsto \color{blue}{0.5} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -0.49 \lor \neg \left(t \leq 0.65\right):\\ \;\;\;\;1 + \left(-0.16666666666666666 + \frac{-0.2222222222222222}{t}\right)\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \]
  5. Add Preprocessing

Alternative 9: 99.0% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq -0.49 \lor \neg \left(t \leq 0.65\right):\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (or (<= t -0.49) (not (<= t 0.65)))
   (- 0.8333333333333334 (/ 0.2222222222222222 t))
   0.5))
double code(double t) {
	double tmp;
	if ((t <= -0.49) || !(t <= 0.65)) {
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	} else {
		tmp = 0.5;
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: tmp
    if ((t <= (-0.49d0)) .or. (.not. (t <= 0.65d0))) then
        tmp = 0.8333333333333334d0 - (0.2222222222222222d0 / t)
    else
        tmp = 0.5d0
    end if
    code = tmp
end function
public static double code(double t) {
	double tmp;
	if ((t <= -0.49) || !(t <= 0.65)) {
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	} else {
		tmp = 0.5;
	}
	return tmp;
}
def code(t):
	tmp = 0
	if (t <= -0.49) or not (t <= 0.65):
		tmp = 0.8333333333333334 - (0.2222222222222222 / t)
	else:
		tmp = 0.5
	return tmp
function code(t)
	tmp = 0.0
	if ((t <= -0.49) || !(t <= 0.65))
		tmp = Float64(0.8333333333333334 - Float64(0.2222222222222222 / t));
	else
		tmp = 0.5;
	end
	return tmp
end
function tmp_2 = code(t)
	tmp = 0.0;
	if ((t <= -0.49) || ~((t <= 0.65)))
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	else
		tmp = 0.5;
	end
	tmp_2 = tmp;
end
code[t_] := If[Or[LessEqual[t, -0.49], N[Not[LessEqual[t, 0.65]], $MachinePrecision]], N[(0.8333333333333334 - N[(0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision], 0.5]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.49 \lor \neg \left(t \leq 0.65\right):\\
\;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < -0.48999999999999999 or 0.650000000000000022 < 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. Step-by-step derivation
      1. sub-neg100.0%

        \[\leadsto \color{blue}{1 + \left(-\frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}\right)} \]
      2. distribute-neg-frac100.0%

        \[\leadsto 1 + \color{blue}{\frac{-1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}} \]
      3. metadata-eval100.0%

        \[\leadsto 1 + \frac{\color{blue}{-1}}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
      4. +-commutative100.0%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) + 2}} \]
      5. fma-define100.0%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\mathsf{fma}\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2\right)}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{-1}{\mathsf{fma}\left(2 - \frac{-2}{-1 - t}, 2 - \frac{-2}{-1 - t}, 2\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in t around inf 98.8%

      \[\leadsto \color{blue}{0.8333333333333334 - 0.2222222222222222 \cdot \frac{1}{t}} \]
    6. Step-by-step derivation
      1. associate-*r/98.8%

        \[\leadsto 0.8333333333333334 - \color{blue}{\frac{0.2222222222222222 \cdot 1}{t}} \]
      2. metadata-eval98.8%

        \[\leadsto 0.8333333333333334 - \frac{\color{blue}{0.2222222222222222}}{t} \]
    7. Simplified98.8%

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

    if -0.48999999999999999 < t < 0.650000000000000022

    1. Initial program 99.2%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Step-by-step derivation
      1. sub-neg99.2%

        \[\leadsto \color{blue}{1 + \left(-\frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}\right)} \]
      2. distribute-neg-frac99.2%

        \[\leadsto 1 + \color{blue}{\frac{-1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}} \]
      3. metadata-eval99.2%

        \[\leadsto 1 + \frac{\color{blue}{-1}}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
      4. +-commutative99.2%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) + 2}} \]
      5. fma-define99.2%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\mathsf{fma}\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2\right)}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{-1}{\mathsf{fma}\left(2 - \frac{-2}{-1 - t}, 2 - \frac{-2}{-1 - t}, 2\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in t around 0 98.8%

      \[\leadsto \color{blue}{0.5} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -0.49 \lor \neg \left(t \leq 0.65\right):\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \]
  5. Add Preprocessing

Alternative 10: 98.5% 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. Step-by-step derivation
      1. sub-neg100.0%

        \[\leadsto \color{blue}{1 + \left(-\frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}\right)} \]
      2. distribute-neg-frac100.0%

        \[\leadsto 1 + \color{blue}{\frac{-1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}} \]
      3. metadata-eval100.0%

        \[\leadsto 1 + \frac{\color{blue}{-1}}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
      4. +-commutative100.0%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) + 2}} \]
      5. fma-define100.0%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\mathsf{fma}\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2\right)}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{-1}{\mathsf{fma}\left(2 - \frac{-2}{-1 - t}, 2 - \frac{-2}{-1 - t}, 2\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in t around inf 97.6%

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

    if -0.330000000000000016 < t < 1

    1. Initial program 99.2%

      \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Step-by-step derivation
      1. sub-neg99.2%

        \[\leadsto \color{blue}{1 + \left(-\frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}\right)} \]
      2. distribute-neg-frac99.2%

        \[\leadsto 1 + \color{blue}{\frac{-1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}} \]
      3. metadata-eval99.2%

        \[\leadsto 1 + \frac{\color{blue}{-1}}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
      4. +-commutative99.2%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) + 2}} \]
      5. fma-define99.2%

        \[\leadsto 1 + \frac{-1}{\color{blue}{\mathsf{fma}\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2\right)}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{1 + \frac{-1}{\mathsf{fma}\left(2 - \frac{-2}{-1 - t}, 2 - \frac{-2}{-1 - t}, 2\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in t around 0 98.8%

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

Alternative 11: 59.7% 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 99.6%

    \[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
  2. Step-by-step derivation
    1. sub-neg99.6%

      \[\leadsto \color{blue}{1 + \left(-\frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}\right)} \]
    2. distribute-neg-frac99.6%

      \[\leadsto 1 + \color{blue}{\frac{-1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}} \]
    3. metadata-eval99.6%

      \[\leadsto 1 + \frac{\color{blue}{-1}}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    4. +-commutative99.6%

      \[\leadsto 1 + \frac{-1}{\color{blue}{\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) + 2}} \]
    5. fma-define99.6%

      \[\leadsto 1 + \frac{-1}{\color{blue}{\mathsf{fma}\left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}, 2\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{1 + \frac{-1}{\mathsf{fma}\left(2 - \frac{-2}{-1 - t}, 2 - \frac{-2}{-1 - t}, 2\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in t around 0 59.2%

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

Reproduce

?
herbie shell --seed 2024111 
(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)))))))))