Kahan p13 Example 1

Percentage Accurate: 100.0% → 100.0%
Time: 9.1s
Alternatives: 9
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{2 \cdot t}{1 + t}\\ t_2 := t_1 \cdot t_1\\ \frac{1 + t_2}{2 + t_2} \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (/ (* 2.0 t) (+ 1.0 t))) (t_2 (* t_1 t_1)))
   (/ (+ 1.0 t_2) (+ 2.0 t_2))))
double code(double t) {
	double t_1 = (2.0 * t) / (1.0 + t);
	double t_2 = t_1 * t_1;
	return (1.0 + t_2) / (2.0 + t_2);
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: t_2
    t_1 = (2.0d0 * t) / (1.0d0 + t)
    t_2 = t_1 * t_1
    code = (1.0d0 + t_2) / (2.0d0 + t_2)
end function
public static double code(double t) {
	double t_1 = (2.0 * t) / (1.0 + t);
	double t_2 = t_1 * t_1;
	return (1.0 + t_2) / (2.0 + t_2);
}
def code(t):
	t_1 = (2.0 * t) / (1.0 + t)
	t_2 = t_1 * t_1
	return (1.0 + t_2) / (2.0 + t_2)
function code(t)
	t_1 = Float64(Float64(2.0 * t) / Float64(1.0 + t))
	t_2 = Float64(t_1 * t_1)
	return Float64(Float64(1.0 + t_2) / Float64(2.0 + t_2))
end
function tmp = code(t)
	t_1 = (2.0 * t) / (1.0 + t);
	t_2 = t_1 * t_1;
	tmp = (1.0 + t_2) / (2.0 + t_2);
end
code[t_] := Block[{t$95$1 = N[(N[(2.0 * t), $MachinePrecision] / N[(1.0 + t), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$1 * t$95$1), $MachinePrecision]}, N[(N[(1.0 + t$95$2), $MachinePrecision] / N[(2.0 + t$95$2), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{2 \cdot t}{1 + t}\\
t_2 := t_1 \cdot t_1\\
\frac{1 + t_2}{2 + t_2}
\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 9 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?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{2 \cdot t}{1 + t}\\ t_2 := t_1 \cdot t_1\\ \frac{1 + t_2}{2 + t_2} \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (/ (* 2.0 t) (+ 1.0 t))) (t_2 (* t_1 t_1)))
   (/ (+ 1.0 t_2) (+ 2.0 t_2))))
double code(double t) {
	double t_1 = (2.0 * t) / (1.0 + t);
	double t_2 = t_1 * t_1;
	return (1.0 + t_2) / (2.0 + t_2);
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: t_2
    t_1 = (2.0d0 * t) / (1.0d0 + t)
    t_2 = t_1 * t_1
    code = (1.0d0 + t_2) / (2.0d0 + t_2)
end function
public static double code(double t) {
	double t_1 = (2.0 * t) / (1.0 + t);
	double t_2 = t_1 * t_1;
	return (1.0 + t_2) / (2.0 + t_2);
}
def code(t):
	t_1 = (2.0 * t) / (1.0 + t)
	t_2 = t_1 * t_1
	return (1.0 + t_2) / (2.0 + t_2)
function code(t)
	t_1 = Float64(Float64(2.0 * t) / Float64(1.0 + t))
	t_2 = Float64(t_1 * t_1)
	return Float64(Float64(1.0 + t_2) / Float64(2.0 + t_2))
end
function tmp = code(t)
	t_1 = (2.0 * t) / (1.0 + t);
	t_2 = t_1 * t_1;
	tmp = (1.0 + t_2) / (2.0 + t_2);
end
code[t_] := Block[{t$95$1 = N[(N[(2.0 * t), $MachinePrecision] / N[(1.0 + t), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$1 * t$95$1), $MachinePrecision]}, N[(N[(1.0 + t$95$2), $MachinePrecision] / N[(2.0 + t$95$2), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{2 \cdot t}{1 + t}\\
t_2 := t_1 \cdot t_1\\
\frac{1 + t_2}{2 + t_2}
\end{array}
\end{array}

Alternative 1: 100.0% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{2}{\frac{1 + t}{t}}\\ \frac{1 + \left(1 + \left({t_1}^{2} + -1\right)\right)}{2 + t_1 \cdot t_1} \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (/ 2.0 (/ (+ 1.0 t) t))))
   (/ (+ 1.0 (+ 1.0 (+ (pow t_1 2.0) -1.0))) (+ 2.0 (* t_1 t_1)))))
double code(double t) {
	double t_1 = 2.0 / ((1.0 + t) / t);
	return (1.0 + (1.0 + (pow(t_1, 2.0) + -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 / ((1.0d0 + t) / t)
    code = (1.0d0 + (1.0d0 + ((t_1 ** 2.0d0) + (-1.0d0)))) / (2.0d0 + (t_1 * t_1))
end function
public static double code(double t) {
	double t_1 = 2.0 / ((1.0 + t) / t);
	return (1.0 + (1.0 + (Math.pow(t_1, 2.0) + -1.0))) / (2.0 + (t_1 * t_1));
}
def code(t):
	t_1 = 2.0 / ((1.0 + t) / t)
	return (1.0 + (1.0 + (math.pow(t_1, 2.0) + -1.0))) / (2.0 + (t_1 * t_1))
function code(t)
	t_1 = Float64(2.0 / Float64(Float64(1.0 + t) / t))
	return Float64(Float64(1.0 + Float64(1.0 + Float64((t_1 ^ 2.0) + -1.0))) / Float64(2.0 + Float64(t_1 * t_1)))
end
function tmp = code(t)
	t_1 = 2.0 / ((1.0 + t) / t);
	tmp = (1.0 + (1.0 + ((t_1 ^ 2.0) + -1.0))) / (2.0 + (t_1 * t_1));
end
code[t_] := Block[{t$95$1 = N[(2.0 / N[(N[(1.0 + t), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]}, N[(N[(1.0 + N[(1.0 + N[(N[Power[t$95$1, 2.0], $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(2.0 + N[(t$95$1 * t$95$1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

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

    \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
  2. Step-by-step derivation
    1. associate-/l*99.6%

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

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

      \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}} \]
    4. associate-/l*100.0%

      \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}} \]
  4. Step-by-step derivation
    1. frac-times100.0%

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

      \[\leadsto \frac{1 + \frac{\color{blue}{4}}{\frac{1 + t}{t} \cdot \frac{1 + t}{t}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    3. clear-num100.0%

      \[\leadsto \frac{1 + \color{blue}{\frac{1}{\frac{\frac{1 + t}{t} \cdot \frac{1 + t}{t}}{4}}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    4. frac-times69.5%

      \[\leadsto \frac{1 + \frac{1}{\frac{\color{blue}{\frac{\left(1 + t\right) \cdot \left(1 + t\right)}{t \cdot t}}}{4}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    5. associate-/r*69.1%

      \[\leadsto \frac{1 + \frac{1}{\color{blue}{\frac{\left(1 + t\right) \cdot \left(1 + t\right)}{\left(t \cdot t\right) \cdot 4}}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    6. associate-*r*69.1%

      \[\leadsto \frac{1 + \frac{1}{\frac{\left(1 + t\right) \cdot \left(1 + t\right)}{\color{blue}{t \cdot \left(t \cdot 4\right)}}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    7. expm1-log1p-u69.1%

      \[\leadsto \frac{1 + \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{1}{\frac{\left(1 + t\right) \cdot \left(1 + t\right)}{t \cdot \left(t \cdot 4\right)}}\right)\right)}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    8. clear-num69.1%

      \[\leadsto \frac{1 + \mathsf{expm1}\left(\mathsf{log1p}\left(\color{blue}{\frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}\right)\right)}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    9. expm1-udef68.5%

      \[\leadsto \frac{1 + \color{blue}{\left(e^{\mathsf{log1p}\left(\frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}\right)} - 1\right)}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
  5. Applied egg-rr99.6%

    \[\leadsto \frac{1 + \color{blue}{\left(\left(1 + {\left(\frac{2 \cdot t}{1 + t}\right)}^{2}\right) - 1\right)}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
  6. Step-by-step derivation
    1. associate--l+99.6%

      \[\leadsto \frac{1 + \color{blue}{\left(1 + \left({\left(\frac{2 \cdot t}{1 + t}\right)}^{2} - 1\right)\right)}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    2. associate-/l*100.0%

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

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

    \[\leadsto \frac{1 + \color{blue}{\left(1 + \left({\left(\frac{2}{\frac{t + 1}{t}}\right)}^{2} - 1\right)\right)}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
  8. Final simplification100.0%

    \[\leadsto \frac{1 + \left(1 + \left({\left(\frac{2}{\frac{1 + t}{t}}\right)}^{2} + -1\right)\right)}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]

Alternative 2: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{2}{\frac{1 + t}{t}}\\ t_2 := \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}\\ \mathbf{if}\;t \leq -1 \cdot 10^{+154}:\\ \;\;\;\;0.8333333333333334\\ \mathbf{elif}\;t \leq 100000000000:\\ \;\;\;\;\frac{1 + t_2}{2 + t_2}\\ \mathbf{else}:\\ \;\;\;\;\frac{1 + \left(4 - \frac{8}{t}\right)}{2 + t_1 \cdot t_1}\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (/ 2.0 (/ (+ 1.0 t) t)))
        (t_2 (/ (* t (* t 4.0)) (* (+ 1.0 t) (+ 1.0 t)))))
   (if (<= t -1e+154)
     0.8333333333333334
     (if (<= t 100000000000.0)
       (/ (+ 1.0 t_2) (+ 2.0 t_2))
       (/ (+ 1.0 (- 4.0 (/ 8.0 t))) (+ 2.0 (* t_1 t_1)))))))
double code(double t) {
	double t_1 = 2.0 / ((1.0 + t) / t);
	double t_2 = (t * (t * 4.0)) / ((1.0 + t) * (1.0 + t));
	double tmp;
	if (t <= -1e+154) {
		tmp = 0.8333333333333334;
	} else if (t <= 100000000000.0) {
		tmp = (1.0 + t_2) / (2.0 + t_2);
	} else {
		tmp = (1.0 + (4.0 - (8.0 / t))) / (2.0 + (t_1 * t_1));
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: t_2
    real(8) :: tmp
    t_1 = 2.0d0 / ((1.0d0 + t) / t)
    t_2 = (t * (t * 4.0d0)) / ((1.0d0 + t) * (1.0d0 + t))
    if (t <= (-1d+154)) then
        tmp = 0.8333333333333334d0
    else if (t <= 100000000000.0d0) then
        tmp = (1.0d0 + t_2) / (2.0d0 + t_2)
    else
        tmp = (1.0d0 + (4.0d0 - (8.0d0 / t))) / (2.0d0 + (t_1 * t_1))
    end if
    code = tmp
end function
public static double code(double t) {
	double t_1 = 2.0 / ((1.0 + t) / t);
	double t_2 = (t * (t * 4.0)) / ((1.0 + t) * (1.0 + t));
	double tmp;
	if (t <= -1e+154) {
		tmp = 0.8333333333333334;
	} else if (t <= 100000000000.0) {
		tmp = (1.0 + t_2) / (2.0 + t_2);
	} else {
		tmp = (1.0 + (4.0 - (8.0 / t))) / (2.0 + (t_1 * t_1));
	}
	return tmp;
}
def code(t):
	t_1 = 2.0 / ((1.0 + t) / t)
	t_2 = (t * (t * 4.0)) / ((1.0 + t) * (1.0 + t))
	tmp = 0
	if t <= -1e+154:
		tmp = 0.8333333333333334
	elif t <= 100000000000.0:
		tmp = (1.0 + t_2) / (2.0 + t_2)
	else:
		tmp = (1.0 + (4.0 - (8.0 / t))) / (2.0 + (t_1 * t_1))
	return tmp
function code(t)
	t_1 = Float64(2.0 / Float64(Float64(1.0 + t) / t))
	t_2 = Float64(Float64(t * Float64(t * 4.0)) / Float64(Float64(1.0 + t) * Float64(1.0 + t)))
	tmp = 0.0
	if (t <= -1e+154)
		tmp = 0.8333333333333334;
	elseif (t <= 100000000000.0)
		tmp = Float64(Float64(1.0 + t_2) / Float64(2.0 + t_2));
	else
		tmp = Float64(Float64(1.0 + Float64(4.0 - Float64(8.0 / t))) / Float64(2.0 + Float64(t_1 * t_1)));
	end
	return tmp
end
function tmp_2 = code(t)
	t_1 = 2.0 / ((1.0 + t) / t);
	t_2 = (t * (t * 4.0)) / ((1.0 + t) * (1.0 + t));
	tmp = 0.0;
	if (t <= -1e+154)
		tmp = 0.8333333333333334;
	elseif (t <= 100000000000.0)
		tmp = (1.0 + t_2) / (2.0 + t_2);
	else
		tmp = (1.0 + (4.0 - (8.0 / t))) / (2.0 + (t_1 * t_1));
	end
	tmp_2 = tmp;
end
code[t_] := Block[{t$95$1 = N[(2.0 / N[(N[(1.0 + t), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(t * N[(t * 4.0), $MachinePrecision]), $MachinePrecision] / N[(N[(1.0 + t), $MachinePrecision] * N[(1.0 + t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t, -1e+154], 0.8333333333333334, If[LessEqual[t, 100000000000.0], N[(N[(1.0 + t$95$2), $MachinePrecision] / N[(2.0 + t$95$2), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 + N[(4.0 - N[(8.0 / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(2.0 + N[(t$95$1 * t$95$1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{2}{\frac{1 + t}{t}}\\
t_2 := \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}\\
\mathbf{if}\;t \leq -1 \cdot 10^{+154}:\\
\;\;\;\;0.8333333333333334\\

\mathbf{elif}\;t \leq 100000000000:\\
\;\;\;\;\frac{1 + t_2}{2 + t_2}\\

\mathbf{else}:\\
\;\;\;\;\frac{1 + \left(4 - \frac{8}{t}\right)}{2 + t_1 \cdot t_1}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if t < -1.00000000000000004e154

    1. Initial program 100.0%

      \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
    2. Step-by-step derivation
      1. associate-/l*100.0%

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      2. associate-/l*100.0%

        \[\leadsto \frac{1 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      3. associate-/l*100.0%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}} \]
      4. associate-/l*100.0%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}} \]
    4. Taylor expanded in t around inf 100.0%

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

    if -1.00000000000000004e154 < t < 1e11

    1. Initial program 100.0%

      \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
    2. Step-by-step derivation
      1. times-frac99.9%

        \[\leadsto \frac{1 + \color{blue}{\frac{\left(2 \cdot t\right) \cdot \left(2 \cdot t\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      2. sqr-neg99.9%

        \[\leadsto \frac{1 + \frac{\color{blue}{\left(-2 \cdot t\right) \cdot \left(-2 \cdot t\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      3. distribute-rgt-neg-out99.9%

        \[\leadsto \frac{1 + \frac{\color{blue}{\left(2 \cdot \left(-t\right)\right)} \cdot \left(-2 \cdot t\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      4. distribute-rgt-neg-out99.9%

        \[\leadsto \frac{1 + \frac{\left(2 \cdot \left(-t\right)\right) \cdot \color{blue}{\left(2 \cdot \left(-t\right)\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      5. swap-sqr99.9%

        \[\leadsto \frac{1 + \frac{\color{blue}{\left(2 \cdot 2\right) \cdot \left(\left(-t\right) \cdot \left(-t\right)\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      6. *-commutative99.9%

        \[\leadsto \frac{1 + \frac{\color{blue}{\left(\left(-t\right) \cdot \left(-t\right)\right) \cdot \left(2 \cdot 2\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      7. sqr-neg99.9%

        \[\leadsto \frac{1 + \frac{\color{blue}{\left(t \cdot t\right)} \cdot \left(2 \cdot 2\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      8. associate-*r*99.9%

        \[\leadsto \frac{1 + \frac{\color{blue}{t \cdot \left(t \cdot \left(2 \cdot 2\right)\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      9. metadata-eval99.9%

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot \color{blue}{4}\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      10. times-frac100.0%

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \color{blue}{\frac{\left(2 \cdot t\right) \cdot \left(2 \cdot t\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}} \]
    3. Simplified100.0%

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

    if 1e11 < t

    1. Initial program 98.7%

      \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
    2. Step-by-step derivation
      1. associate-/l*98.7%

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      2. associate-/l*98.7%

        \[\leadsto \frac{1 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      3. associate-/l*98.8%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}} \]
      4. associate-/l*100.0%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}} \]
    4. Taylor expanded in t around inf 100.0%

      \[\leadsto \frac{1 + \color{blue}{\left(4 - 8 \cdot \frac{1}{t}\right)}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    5. Step-by-step derivation
      1. associate-*r/100.0%

        \[\leadsto \frac{1 + \left(4 - \color{blue}{\frac{8 \cdot 1}{t}}\right)}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
      2. metadata-eval100.0%

        \[\leadsto \frac{1 + \left(4 - \frac{\color{blue}{8}}{t}\right)}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    6. Simplified100.0%

      \[\leadsto \frac{1 + \color{blue}{\left(4 - \frac{8}{t}\right)}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification100.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -1 \cdot 10^{+154}:\\ \;\;\;\;0.8333333333333334\\ \mathbf{elif}\;t \leq 100000000000:\\ \;\;\;\;\frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1 + \left(4 - \frac{8}{t}\right)}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}\\ \end{array} \]

Alternative 3: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{2}{\frac{1 + t}{t}}\\ t_2 := t_1 \cdot t_1\\ \frac{1 + t_2}{2 + t_2} \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (/ 2.0 (/ (+ 1.0 t) t))) (t_2 (* t_1 t_1)))
   (/ (+ 1.0 t_2) (+ 2.0 t_2))))
double code(double t) {
	double t_1 = 2.0 / ((1.0 + t) / t);
	double t_2 = t_1 * t_1;
	return (1.0 + t_2) / (2.0 + t_2);
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: t_2
    t_1 = 2.0d0 / ((1.0d0 + t) / t)
    t_2 = t_1 * t_1
    code = (1.0d0 + t_2) / (2.0d0 + t_2)
end function
public static double code(double t) {
	double t_1 = 2.0 / ((1.0 + t) / t);
	double t_2 = t_1 * t_1;
	return (1.0 + t_2) / (2.0 + t_2);
}
def code(t):
	t_1 = 2.0 / ((1.0 + t) / t)
	t_2 = t_1 * t_1
	return (1.0 + t_2) / (2.0 + t_2)
function code(t)
	t_1 = Float64(2.0 / Float64(Float64(1.0 + t) / t))
	t_2 = Float64(t_1 * t_1)
	return Float64(Float64(1.0 + t_2) / Float64(2.0 + t_2))
end
function tmp = code(t)
	t_1 = 2.0 / ((1.0 + t) / t);
	t_2 = t_1 * t_1;
	tmp = (1.0 + t_2) / (2.0 + t_2);
end
code[t_] := Block[{t$95$1 = N[(2.0 / N[(N[(1.0 + t), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$1 * t$95$1), $MachinePrecision]}, N[(N[(1.0 + t$95$2), $MachinePrecision] / N[(2.0 + t$95$2), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{2}{\frac{1 + t}{t}}\\
t_2 := t_1 \cdot t_1\\
\frac{1 + t_2}{2 + t_2}
\end{array}
\end{array}
Derivation
  1. Initial program 99.6%

    \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
  2. Step-by-step derivation
    1. associate-/l*99.6%

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

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

      \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}} \]
    4. associate-/l*100.0%

      \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}} \]
  4. Final simplification100.0%

    \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]

Alternative 4: 99.3% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := t \cdot \left(t \cdot 4\right)\\ t_2 := \frac{2}{\frac{1 + t}{t}}\\ \mathbf{if}\;t \leq -0.43:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \mathbf{elif}\;t \leq 2.6:\\ \;\;\;\;\frac{1 + \frac{t_1}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t_1}{1 + 2 \cdot t}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1 + \left(4 - \frac{8}{t}\right)}{2 + t_2 \cdot t_2}\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (* t (* t 4.0))) (t_2 (/ 2.0 (/ (+ 1.0 t) t))))
   (if (<= t -0.43)
     (- 0.8333333333333334 (/ 0.2222222222222222 t))
     (if (<= t 2.6)
       (/
        (+ 1.0 (/ t_1 (* (+ 1.0 t) (+ 1.0 t))))
        (+ 2.0 (/ t_1 (+ 1.0 (* 2.0 t)))))
       (/ (+ 1.0 (- 4.0 (/ 8.0 t))) (+ 2.0 (* t_2 t_2)))))))
double code(double t) {
	double t_1 = t * (t * 4.0);
	double t_2 = 2.0 / ((1.0 + t) / t);
	double tmp;
	if (t <= -0.43) {
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	} else if (t <= 2.6) {
		tmp = (1.0 + (t_1 / ((1.0 + t) * (1.0 + t)))) / (2.0 + (t_1 / (1.0 + (2.0 * t))));
	} else {
		tmp = (1.0 + (4.0 - (8.0 / t))) / (2.0 + (t_2 * t_2));
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: t_2
    real(8) :: tmp
    t_1 = t * (t * 4.0d0)
    t_2 = 2.0d0 / ((1.0d0 + t) / t)
    if (t <= (-0.43d0)) then
        tmp = 0.8333333333333334d0 - (0.2222222222222222d0 / t)
    else if (t <= 2.6d0) then
        tmp = (1.0d0 + (t_1 / ((1.0d0 + t) * (1.0d0 + t)))) / (2.0d0 + (t_1 / (1.0d0 + (2.0d0 * t))))
    else
        tmp = (1.0d0 + (4.0d0 - (8.0d0 / t))) / (2.0d0 + (t_2 * t_2))
    end if
    code = tmp
end function
public static double code(double t) {
	double t_1 = t * (t * 4.0);
	double t_2 = 2.0 / ((1.0 + t) / t);
	double tmp;
	if (t <= -0.43) {
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	} else if (t <= 2.6) {
		tmp = (1.0 + (t_1 / ((1.0 + t) * (1.0 + t)))) / (2.0 + (t_1 / (1.0 + (2.0 * t))));
	} else {
		tmp = (1.0 + (4.0 - (8.0 / t))) / (2.0 + (t_2 * t_2));
	}
	return tmp;
}
def code(t):
	t_1 = t * (t * 4.0)
	t_2 = 2.0 / ((1.0 + t) / t)
	tmp = 0
	if t <= -0.43:
		tmp = 0.8333333333333334 - (0.2222222222222222 / t)
	elif t <= 2.6:
		tmp = (1.0 + (t_1 / ((1.0 + t) * (1.0 + t)))) / (2.0 + (t_1 / (1.0 + (2.0 * t))))
	else:
		tmp = (1.0 + (4.0 - (8.0 / t))) / (2.0 + (t_2 * t_2))
	return tmp
function code(t)
	t_1 = Float64(t * Float64(t * 4.0))
	t_2 = Float64(2.0 / Float64(Float64(1.0 + t) / t))
	tmp = 0.0
	if (t <= -0.43)
		tmp = Float64(0.8333333333333334 - Float64(0.2222222222222222 / t));
	elseif (t <= 2.6)
		tmp = Float64(Float64(1.0 + Float64(t_1 / Float64(Float64(1.0 + t) * Float64(1.0 + t)))) / Float64(2.0 + Float64(t_1 / Float64(1.0 + Float64(2.0 * t)))));
	else
		tmp = Float64(Float64(1.0 + Float64(4.0 - Float64(8.0 / t))) / Float64(2.0 + Float64(t_2 * t_2)));
	end
	return tmp
end
function tmp_2 = code(t)
	t_1 = t * (t * 4.0);
	t_2 = 2.0 / ((1.0 + t) / t);
	tmp = 0.0;
	if (t <= -0.43)
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	elseif (t <= 2.6)
		tmp = (1.0 + (t_1 / ((1.0 + t) * (1.0 + t)))) / (2.0 + (t_1 / (1.0 + (2.0 * t))));
	else
		tmp = (1.0 + (4.0 - (8.0 / t))) / (2.0 + (t_2 * t_2));
	end
	tmp_2 = tmp;
end
code[t_] := Block[{t$95$1 = N[(t * N[(t * 4.0), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(2.0 / N[(N[(1.0 + t), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t, -0.43], N[(0.8333333333333334 - N[(0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision], If[LessEqual[t, 2.6], N[(N[(1.0 + N[(t$95$1 / N[(N[(1.0 + t), $MachinePrecision] * N[(1.0 + t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(2.0 + N[(t$95$1 / N[(1.0 + N[(2.0 * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 + N[(4.0 - N[(8.0 / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(2.0 + N[(t$95$2 * t$95$2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := t \cdot \left(t \cdot 4\right)\\
t_2 := \frac{2}{\frac{1 + t}{t}}\\
\mathbf{if}\;t \leq -0.43:\\
\;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\

\mathbf{elif}\;t \leq 2.6:\\
\;\;\;\;\frac{1 + \frac{t_1}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t_1}{1 + 2 \cdot t}}\\

\mathbf{else}:\\
\;\;\;\;\frac{1 + \left(4 - \frac{8}{t}\right)}{2 + t_2 \cdot t_2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if t < -0.429999999999999993

    1. Initial program 100.0%

      \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
    2. Step-by-step derivation
      1. associate-/l*100.0%

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      2. associate-/l*100.0%

        \[\leadsto \frac{1 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      3. associate-/l*100.0%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}} \]
      4. associate-/l*100.0%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}} \]
    4. Taylor expanded in t around inf 99.6%

      \[\leadsto \color{blue}{0.8333333333333334 - 0.2222222222222222 \cdot \frac{1}{t}} \]
    5. Step-by-step derivation
      1. associate-*r/99.6%

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

        \[\leadsto 0.8333333333333334 - \frac{\color{blue}{0.2222222222222222}}{t} \]
    6. Simplified99.6%

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

    if -0.429999999999999993 < t < 2.60000000000000009

    1. Initial program 99.9%

      \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
    2. Step-by-step derivation
      1. times-frac99.9%

        \[\leadsto \frac{1 + \color{blue}{\frac{\left(2 \cdot t\right) \cdot \left(2 \cdot t\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      2. sqr-neg99.9%

        \[\leadsto \frac{1 + \frac{\color{blue}{\left(-2 \cdot t\right) \cdot \left(-2 \cdot t\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      3. distribute-rgt-neg-out99.9%

        \[\leadsto \frac{1 + \frac{\color{blue}{\left(2 \cdot \left(-t\right)\right)} \cdot \left(-2 \cdot t\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      4. distribute-rgt-neg-out99.9%

        \[\leadsto \frac{1 + \frac{\left(2 \cdot \left(-t\right)\right) \cdot \color{blue}{\left(2 \cdot \left(-t\right)\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      5. swap-sqr99.9%

        \[\leadsto \frac{1 + \frac{\color{blue}{\left(2 \cdot 2\right) \cdot \left(\left(-t\right) \cdot \left(-t\right)\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      6. *-commutative99.9%

        \[\leadsto \frac{1 + \frac{\color{blue}{\left(\left(-t\right) \cdot \left(-t\right)\right) \cdot \left(2 \cdot 2\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      7. sqr-neg99.9%

        \[\leadsto \frac{1 + \frac{\color{blue}{\left(t \cdot t\right)} \cdot \left(2 \cdot 2\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      8. associate-*r*99.9%

        \[\leadsto \frac{1 + \frac{\color{blue}{t \cdot \left(t \cdot \left(2 \cdot 2\right)\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      9. metadata-eval99.9%

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot \color{blue}{4}\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      10. times-frac99.9%

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \color{blue}{\frac{\left(2 \cdot t\right) \cdot \left(2 \cdot t\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}} \]
    4. Taylor expanded in t around 0 99.8%

      \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\color{blue}{1 + 2 \cdot t}}} \]
    5. Step-by-step derivation
      1. +-commutative99.8%

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\color{blue}{2 \cdot t + 1}}} \]
    6. Simplified99.8%

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

    if 2.60000000000000009 < t

    1. Initial program 98.8%

      \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
    2. Step-by-step derivation
      1. associate-/l*98.7%

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      2. associate-/l*98.7%

        \[\leadsto \frac{1 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      3. associate-/l*98.8%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}} \]
      4. associate-/l*100.0%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}} \]
    4. Taylor expanded in t around inf 100.0%

      \[\leadsto \frac{1 + \color{blue}{\left(4 - 8 \cdot \frac{1}{t}\right)}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    5. Step-by-step derivation
      1. associate-*r/100.0%

        \[\leadsto \frac{1 + \left(4 - \color{blue}{\frac{8 \cdot 1}{t}}\right)}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
      2. metadata-eval100.0%

        \[\leadsto \frac{1 + \left(4 - \frac{\color{blue}{8}}{t}\right)}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    6. Simplified100.0%

      \[\leadsto \frac{1 + \color{blue}{\left(4 - \frac{8}{t}\right)}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -0.43:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \mathbf{elif}\;t \leq 2.6:\\ \;\;\;\;\frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{1 + 2 \cdot t}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1 + \left(4 - \frac{8}{t}\right)}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}\\ \end{array} \]

Alternative 5: 99.3% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{2}{\frac{1 + t}{t}}\\ t_2 := \frac{t \cdot \left(t \cdot 4\right)}{1 + 2 \cdot t}\\ \mathbf{if}\;t \leq -0.6:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \mathbf{elif}\;t \leq 4.2:\\ \;\;\;\;\frac{1 + t_2}{2 + t_2}\\ \mathbf{else}:\\ \;\;\;\;\frac{1 + \left(4 - \frac{8}{t}\right)}{2 + t_1 \cdot t_1}\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (/ 2.0 (/ (+ 1.0 t) t)))
        (t_2 (/ (* t (* t 4.0)) (+ 1.0 (* 2.0 t)))))
   (if (<= t -0.6)
     (- 0.8333333333333334 (/ 0.2222222222222222 t))
     (if (<= t 4.2)
       (/ (+ 1.0 t_2) (+ 2.0 t_2))
       (/ (+ 1.0 (- 4.0 (/ 8.0 t))) (+ 2.0 (* t_1 t_1)))))))
double code(double t) {
	double t_1 = 2.0 / ((1.0 + t) / t);
	double t_2 = (t * (t * 4.0)) / (1.0 + (2.0 * t));
	double tmp;
	if (t <= -0.6) {
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	} else if (t <= 4.2) {
		tmp = (1.0 + t_2) / (2.0 + t_2);
	} else {
		tmp = (1.0 + (4.0 - (8.0 / t))) / (2.0 + (t_1 * t_1));
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: t_2
    real(8) :: tmp
    t_1 = 2.0d0 / ((1.0d0 + t) / t)
    t_2 = (t * (t * 4.0d0)) / (1.0d0 + (2.0d0 * t))
    if (t <= (-0.6d0)) then
        tmp = 0.8333333333333334d0 - (0.2222222222222222d0 / t)
    else if (t <= 4.2d0) then
        tmp = (1.0d0 + t_2) / (2.0d0 + t_2)
    else
        tmp = (1.0d0 + (4.0d0 - (8.0d0 / t))) / (2.0d0 + (t_1 * t_1))
    end if
    code = tmp
end function
public static double code(double t) {
	double t_1 = 2.0 / ((1.0 + t) / t);
	double t_2 = (t * (t * 4.0)) / (1.0 + (2.0 * t));
	double tmp;
	if (t <= -0.6) {
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	} else if (t <= 4.2) {
		tmp = (1.0 + t_2) / (2.0 + t_2);
	} else {
		tmp = (1.0 + (4.0 - (8.0 / t))) / (2.0 + (t_1 * t_1));
	}
	return tmp;
}
def code(t):
	t_1 = 2.0 / ((1.0 + t) / t)
	t_2 = (t * (t * 4.0)) / (1.0 + (2.0 * t))
	tmp = 0
	if t <= -0.6:
		tmp = 0.8333333333333334 - (0.2222222222222222 / t)
	elif t <= 4.2:
		tmp = (1.0 + t_2) / (2.0 + t_2)
	else:
		tmp = (1.0 + (4.0 - (8.0 / t))) / (2.0 + (t_1 * t_1))
	return tmp
function code(t)
	t_1 = Float64(2.0 / Float64(Float64(1.0 + t) / t))
	t_2 = Float64(Float64(t * Float64(t * 4.0)) / Float64(1.0 + Float64(2.0 * t)))
	tmp = 0.0
	if (t <= -0.6)
		tmp = Float64(0.8333333333333334 - Float64(0.2222222222222222 / t));
	elseif (t <= 4.2)
		tmp = Float64(Float64(1.0 + t_2) / Float64(2.0 + t_2));
	else
		tmp = Float64(Float64(1.0 + Float64(4.0 - Float64(8.0 / t))) / Float64(2.0 + Float64(t_1 * t_1)));
	end
	return tmp
end
function tmp_2 = code(t)
	t_1 = 2.0 / ((1.0 + t) / t);
	t_2 = (t * (t * 4.0)) / (1.0 + (2.0 * t));
	tmp = 0.0;
	if (t <= -0.6)
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	elseif (t <= 4.2)
		tmp = (1.0 + t_2) / (2.0 + t_2);
	else
		tmp = (1.0 + (4.0 - (8.0 / t))) / (2.0 + (t_1 * t_1));
	end
	tmp_2 = tmp;
end
code[t_] := Block[{t$95$1 = N[(2.0 / N[(N[(1.0 + t), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(t * N[(t * 4.0), $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[(2.0 * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t, -0.6], N[(0.8333333333333334 - N[(0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision], If[LessEqual[t, 4.2], N[(N[(1.0 + t$95$2), $MachinePrecision] / N[(2.0 + t$95$2), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 + N[(4.0 - N[(8.0 / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(2.0 + N[(t$95$1 * t$95$1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{2}{\frac{1 + t}{t}}\\
t_2 := \frac{t \cdot \left(t \cdot 4\right)}{1 + 2 \cdot t}\\
\mathbf{if}\;t \leq -0.6:\\
\;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\

\mathbf{elif}\;t \leq 4.2:\\
\;\;\;\;\frac{1 + t_2}{2 + t_2}\\

\mathbf{else}:\\
\;\;\;\;\frac{1 + \left(4 - \frac{8}{t}\right)}{2 + t_1 \cdot t_1}\\


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

    1. Initial program 100.0%

      \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
    2. Step-by-step derivation
      1. associate-/l*100.0%

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      2. associate-/l*100.0%

        \[\leadsto \frac{1 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      3. associate-/l*100.0%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}} \]
      4. associate-/l*100.0%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}} \]
    4. Taylor expanded in t around inf 99.6%

      \[\leadsto \color{blue}{0.8333333333333334 - 0.2222222222222222 \cdot \frac{1}{t}} \]
    5. Step-by-step derivation
      1. associate-*r/99.6%

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

        \[\leadsto 0.8333333333333334 - \frac{\color{blue}{0.2222222222222222}}{t} \]
    6. Simplified99.6%

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

    if -0.599999999999999978 < t < 4.20000000000000018

    1. Initial program 99.9%

      \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
    2. Step-by-step derivation
      1. times-frac99.9%

        \[\leadsto \frac{1 + \color{blue}{\frac{\left(2 \cdot t\right) \cdot \left(2 \cdot t\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      2. sqr-neg99.9%

        \[\leadsto \frac{1 + \frac{\color{blue}{\left(-2 \cdot t\right) \cdot \left(-2 \cdot t\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      3. distribute-rgt-neg-out99.9%

        \[\leadsto \frac{1 + \frac{\color{blue}{\left(2 \cdot \left(-t\right)\right)} \cdot \left(-2 \cdot t\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      4. distribute-rgt-neg-out99.9%

        \[\leadsto \frac{1 + \frac{\left(2 \cdot \left(-t\right)\right) \cdot \color{blue}{\left(2 \cdot \left(-t\right)\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      5. swap-sqr99.9%

        \[\leadsto \frac{1 + \frac{\color{blue}{\left(2 \cdot 2\right) \cdot \left(\left(-t\right) \cdot \left(-t\right)\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      6. *-commutative99.9%

        \[\leadsto \frac{1 + \frac{\color{blue}{\left(\left(-t\right) \cdot \left(-t\right)\right) \cdot \left(2 \cdot 2\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      7. sqr-neg99.9%

        \[\leadsto \frac{1 + \frac{\color{blue}{\left(t \cdot t\right)} \cdot \left(2 \cdot 2\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      8. associate-*r*99.9%

        \[\leadsto \frac{1 + \frac{\color{blue}{t \cdot \left(t \cdot \left(2 \cdot 2\right)\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      9. metadata-eval99.9%

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot \color{blue}{4}\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      10. times-frac99.9%

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \color{blue}{\frac{\left(2 \cdot t\right) \cdot \left(2 \cdot t\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}} \]
    4. Taylor expanded in t around 0 99.8%

      \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\color{blue}{1 + 2 \cdot t}}} \]
    5. Step-by-step derivation
      1. +-commutative99.8%

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\color{blue}{2 \cdot t + 1}}} \]
    6. Simplified99.8%

      \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\color{blue}{2 \cdot t + 1}}} \]
    7. Taylor expanded in t around 0 99.8%

      \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\color{blue}{1 + 2 \cdot t}}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{2 \cdot t + 1}} \]
    8. Step-by-step derivation
      1. +-commutative99.8%

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\color{blue}{2 \cdot t + 1}}} \]
    9. Simplified99.8%

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

    if 4.20000000000000018 < t

    1. Initial program 98.8%

      \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
    2. Step-by-step derivation
      1. associate-/l*98.7%

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      2. associate-/l*98.7%

        \[\leadsto \frac{1 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      3. associate-/l*98.8%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}} \]
      4. associate-/l*100.0%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}} \]
    4. Taylor expanded in t around inf 100.0%

      \[\leadsto \frac{1 + \color{blue}{\left(4 - 8 \cdot \frac{1}{t}\right)}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    5. Step-by-step derivation
      1. associate-*r/100.0%

        \[\leadsto \frac{1 + \left(4 - \color{blue}{\frac{8 \cdot 1}{t}}\right)}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
      2. metadata-eval100.0%

        \[\leadsto \frac{1 + \left(4 - \frac{\color{blue}{8}}{t}\right)}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    6. Simplified100.0%

      \[\leadsto \frac{1 + \color{blue}{\left(4 - \frac{8}{t}\right)}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -0.6:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \mathbf{elif}\;t \leq 4.2:\\ \;\;\;\;\frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{1 + 2 \cdot t}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{1 + 2 \cdot t}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1 + \left(4 - \frac{8}{t}\right)}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}\\ \end{array} \]

Alternative 6: 99.0% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{2}{\frac{1 + t}{t}}\\ \mathbf{if}\;t \leq -0.48:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \mathbf{elif}\;t \leq 2.7:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{1 + \left(4 - \frac{8}{t}\right)}{2 + t_1 \cdot t_1}\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (/ 2.0 (/ (+ 1.0 t) t))))
   (if (<= t -0.48)
     (- 0.8333333333333334 (/ 0.2222222222222222 t))
     (if (<= t 2.7) 0.5 (/ (+ 1.0 (- 4.0 (/ 8.0 t))) (+ 2.0 (* t_1 t_1)))))))
double code(double t) {
	double t_1 = 2.0 / ((1.0 + t) / t);
	double tmp;
	if (t <= -0.48) {
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	} else if (t <= 2.7) {
		tmp = 0.5;
	} else {
		tmp = (1.0 + (4.0 - (8.0 / t))) / (2.0 + (t_1 * t_1));
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: tmp
    t_1 = 2.0d0 / ((1.0d0 + t) / t)
    if (t <= (-0.48d0)) then
        tmp = 0.8333333333333334d0 - (0.2222222222222222d0 / t)
    else if (t <= 2.7d0) then
        tmp = 0.5d0
    else
        tmp = (1.0d0 + (4.0d0 - (8.0d0 / t))) / (2.0d0 + (t_1 * t_1))
    end if
    code = tmp
end function
public static double code(double t) {
	double t_1 = 2.0 / ((1.0 + t) / t);
	double tmp;
	if (t <= -0.48) {
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	} else if (t <= 2.7) {
		tmp = 0.5;
	} else {
		tmp = (1.0 + (4.0 - (8.0 / t))) / (2.0 + (t_1 * t_1));
	}
	return tmp;
}
def code(t):
	t_1 = 2.0 / ((1.0 + t) / t)
	tmp = 0
	if t <= -0.48:
		tmp = 0.8333333333333334 - (0.2222222222222222 / t)
	elif t <= 2.7:
		tmp = 0.5
	else:
		tmp = (1.0 + (4.0 - (8.0 / t))) / (2.0 + (t_1 * t_1))
	return tmp
function code(t)
	t_1 = Float64(2.0 / Float64(Float64(1.0 + t) / t))
	tmp = 0.0
	if (t <= -0.48)
		tmp = Float64(0.8333333333333334 - Float64(0.2222222222222222 / t));
	elseif (t <= 2.7)
		tmp = 0.5;
	else
		tmp = Float64(Float64(1.0 + Float64(4.0 - Float64(8.0 / t))) / Float64(2.0 + Float64(t_1 * t_1)));
	end
	return tmp
end
function tmp_2 = code(t)
	t_1 = 2.0 / ((1.0 + t) / t);
	tmp = 0.0;
	if (t <= -0.48)
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	elseif (t <= 2.7)
		tmp = 0.5;
	else
		tmp = (1.0 + (4.0 - (8.0 / t))) / (2.0 + (t_1 * t_1));
	end
	tmp_2 = tmp;
end
code[t_] := Block[{t$95$1 = N[(2.0 / N[(N[(1.0 + t), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t, -0.48], N[(0.8333333333333334 - N[(0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision], If[LessEqual[t, 2.7], 0.5, N[(N[(1.0 + N[(4.0 - N[(8.0 / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(2.0 + N[(t$95$1 * t$95$1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{2}{\frac{1 + t}{t}}\\
\mathbf{if}\;t \leq -0.48:\\
\;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\

\mathbf{elif}\;t \leq 2.7:\\
\;\;\;\;0.5\\

\mathbf{else}:\\
\;\;\;\;\frac{1 + \left(4 - \frac{8}{t}\right)}{2 + t_1 \cdot t_1}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if t < -0.47999999999999998

    1. Initial program 100.0%

      \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
    2. Step-by-step derivation
      1. associate-/l*100.0%

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      2. associate-/l*100.0%

        \[\leadsto \frac{1 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      3. associate-/l*100.0%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}} \]
      4. associate-/l*100.0%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}} \]
    4. Taylor expanded in t around inf 99.6%

      \[\leadsto \color{blue}{0.8333333333333334 - 0.2222222222222222 \cdot \frac{1}{t}} \]
    5. Step-by-step derivation
      1. associate-*r/99.6%

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

        \[\leadsto 0.8333333333333334 - \frac{\color{blue}{0.2222222222222222}}{t} \]
    6. Simplified99.6%

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

    if -0.47999999999999998 < t < 2.7000000000000002

    1. Initial program 99.9%

      \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
    2. Step-by-step derivation
      1. associate-/l*99.9%

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      2. associate-/l*99.9%

        \[\leadsto \frac{1 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      3. associate-/l*99.9%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}} \]
      4. associate-/l*99.9%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}} \]
    4. Taylor expanded in t around 0 99.1%

      \[\leadsto \color{blue}{0.5} \]

    if 2.7000000000000002 < t

    1. Initial program 98.8%

      \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
    2. Step-by-step derivation
      1. associate-/l*98.7%

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      2. associate-/l*98.7%

        \[\leadsto \frac{1 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      3. associate-/l*98.8%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}} \]
      4. associate-/l*100.0%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}} \]
    4. Taylor expanded in t around inf 100.0%

      \[\leadsto \frac{1 + \color{blue}{\left(4 - 8 \cdot \frac{1}{t}\right)}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    5. Step-by-step derivation
      1. associate-*r/100.0%

        \[\leadsto \frac{1 + \left(4 - \color{blue}{\frac{8 \cdot 1}{t}}\right)}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
      2. metadata-eval100.0%

        \[\leadsto \frac{1 + \left(4 - \frac{\color{blue}{8}}{t}\right)}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    6. Simplified100.0%

      \[\leadsto \frac{1 + \color{blue}{\left(4 - \frac{8}{t}\right)}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -0.48:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \mathbf{elif}\;t \leq 2.7:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{1 + \left(4 - \frac{8}{t}\right)}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}\\ \end{array} \]

Alternative 7: 99.1% accurate, 3.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq -0.48 \lor \neg \left(t \leq 0.66\right):\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (or (<= t -0.48) (not (<= t 0.66)))
   (- 0.8333333333333334 (/ 0.2222222222222222 t))
   0.5))
double code(double t) {
	double tmp;
	if ((t <= -0.48) || !(t <= 0.66)) {
		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 <= (-0.48d0)) .or. (.not. (t <= 0.66d0))) 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 <= -0.48) || !(t <= 0.66)) {
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	} else {
		tmp = 0.5;
	}
	return tmp;
}
def code(t):
	tmp = 0
	if (t <= -0.48) or not (t <= 0.66):
		tmp = 0.8333333333333334 - (0.2222222222222222 / t)
	else:
		tmp = 0.5
	return tmp
function code(t)
	tmp = 0.0
	if ((t <= -0.48) || !(t <= 0.66))
		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 <= -0.48) || ~((t <= 0.66)))
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	else
		tmp = 0.5;
	end
	tmp_2 = tmp;
end
code[t_] := If[Or[LessEqual[t, -0.48], N[Not[LessEqual[t, 0.66]], $MachinePrecision]], N[(0.8333333333333334 - N[(0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision], 0.5]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.48 \lor \neg \left(t \leq 0.66\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 < -0.47999999999999998 or 0.660000000000000031 < t

    1. Initial program 99.3%

      \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
    2. Step-by-step derivation
      1. associate-/l*99.3%

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      2. associate-/l*99.3%

        \[\leadsto \frac{1 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      3. associate-/l*99.3%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}} \]
      4. associate-/l*100.0%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}} \]
    4. Taylor expanded in t around inf 99.8%

      \[\leadsto \color{blue}{0.8333333333333334 - 0.2222222222222222 \cdot \frac{1}{t}} \]
    5. Step-by-step derivation
      1. associate-*r/99.8%

        \[\leadsto 0.8333333333333334 - \color{blue}{\frac{0.2222222222222222 \cdot 1}{t}} \]
      2. metadata-eval99.8%

        \[\leadsto 0.8333333333333334 - \frac{\color{blue}{0.2222222222222222}}{t} \]
    6. Simplified99.8%

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

    if -0.47999999999999998 < t < 0.660000000000000031

    1. Initial program 99.9%

      \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
    2. Step-by-step derivation
      1. associate-/l*99.9%

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      2. associate-/l*99.9%

        \[\leadsto \frac{1 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      3. associate-/l*99.9%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}} \]
      4. associate-/l*99.9%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}} \]
    4. Taylor expanded in t around 0 99.1%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -0.48 \lor \neg \left(t \leq 0.66\right):\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \]

Alternative 8: 98.5% accurate, 6.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq -0.34:\\ \;\;\;\;0.8333333333333334\\ \mathbf{elif}\;t \leq 1:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (<= t -0.34) 0.8333333333333334 (if (<= t 1.0) 0.5 0.8333333333333334)))
double code(double t) {
	double tmp;
	if (t <= -0.34) {
		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 <= (-0.34d0)) 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 <= -0.34) {
		tmp = 0.8333333333333334;
	} else if (t <= 1.0) {
		tmp = 0.5;
	} else {
		tmp = 0.8333333333333334;
	}
	return tmp;
}
def code(t):
	tmp = 0
	if t <= -0.34:
		tmp = 0.8333333333333334
	elif t <= 1.0:
		tmp = 0.5
	else:
		tmp = 0.8333333333333334
	return tmp
function code(t)
	tmp = 0.0
	if (t <= -0.34)
		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 <= -0.34)
		tmp = 0.8333333333333334;
	elseif (t <= 1.0)
		tmp = 0.5;
	else
		tmp = 0.8333333333333334;
	end
	tmp_2 = tmp;
end
code[t_] := If[LessEqual[t, -0.34], 0.8333333333333334, If[LessEqual[t, 1.0], 0.5, 0.8333333333333334]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.34:\\
\;\;\;\;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 < -0.340000000000000024 or 1 < t

    1. Initial program 99.3%

      \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
    2. Step-by-step derivation
      1. associate-/l*99.3%

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      2. associate-/l*99.3%

        \[\leadsto \frac{1 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      3. associate-/l*99.3%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}} \]
      4. associate-/l*100.0%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}} \]
    4. Taylor expanded in t around inf 98.9%

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

    if -0.340000000000000024 < t < 1

    1. Initial program 99.9%

      \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
    2. Step-by-step derivation
      1. associate-/l*99.9%

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      2. associate-/l*99.9%

        \[\leadsto \frac{1 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      3. associate-/l*99.9%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}} \]
      4. associate-/l*99.9%

        \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}} \]
    4. Taylor expanded in t around 0 99.1%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -0.34:\\ \;\;\;\;0.8333333333333334\\ \mathbf{elif}\;t \leq 1:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334\\ \end{array} \]

Alternative 9: 60.0% accurate, 35.0× 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%

    \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
  2. Step-by-step derivation
    1. associate-/l*99.6%

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

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

      \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2}{\frac{1 + t}{t}}}} \]
    4. associate-/l*100.0%

      \[\leadsto \frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot \frac{2}{\frac{1 + t}{t}}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{1 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}{2 + \frac{2}{\frac{1 + t}{t}} \cdot \frac{2}{\frac{1 + t}{t}}}} \]
  4. Taylor expanded in t around 0 52.6%

    \[\leadsto \color{blue}{0.5} \]
  5. Final simplification52.6%

    \[\leadsto 0.5 \]

Reproduce

?
herbie shell --seed 2023315 
(FPCore (t)
  :name "Kahan p13 Example 1"
  :precision binary64
  (/ (+ 1.0 (* (/ (* 2.0 t) (+ 1.0 t)) (/ (* 2.0 t) (+ 1.0 t)))) (+ 2.0 (* (/ (* 2.0 t) (+ 1.0 t)) (/ (* 2.0 t) (+ 1.0 t))))))