Octave 3.8, jcobi/1

Percentage Accurate: 75.3% → 99.7%
Time: 12.4s
Alternatives: 9
Speedup: 1.2×

Specification

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

\\
\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2}
\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: 75.3% accurate, 1.0× speedup?

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

\\
\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2}
\end{array}

Alternative 1: 99.7% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2}\\ \mathbf{if}\;t_0 \leq -0.95:\\ \;\;\;\;\frac{\mathsf{fma}\left(\frac{\left(-2 - \beta\right) - \beta}{\alpha}, \frac{\beta + 2}{\alpha}, \frac{\beta + \left(\beta + 2\right)}{\alpha}\right)}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{t_0 + 1}{2}\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (let* ((t_0 (/ (- beta alpha) (+ (+ beta alpha) 2.0))))
   (if (<= t_0 -0.95)
     (/
      (fma
       (/ (- (- -2.0 beta) beta) alpha)
       (/ (+ beta 2.0) alpha)
       (/ (+ beta (+ beta 2.0)) alpha))
      2.0)
     (/ (+ t_0 1.0) 2.0))))
double code(double alpha, double beta) {
	double t_0 = (beta - alpha) / ((beta + alpha) + 2.0);
	double tmp;
	if (t_0 <= -0.95) {
		tmp = fma((((-2.0 - beta) - beta) / alpha), ((beta + 2.0) / alpha), ((beta + (beta + 2.0)) / alpha)) / 2.0;
	} else {
		tmp = (t_0 + 1.0) / 2.0;
	}
	return tmp;
}
function code(alpha, beta)
	t_0 = Float64(Float64(beta - alpha) / Float64(Float64(beta + alpha) + 2.0))
	tmp = 0.0
	if (t_0 <= -0.95)
		tmp = Float64(fma(Float64(Float64(Float64(-2.0 - beta) - beta) / alpha), Float64(Float64(beta + 2.0) / alpha), Float64(Float64(beta + Float64(beta + 2.0)) / alpha)) / 2.0);
	else
		tmp = Float64(Float64(t_0 + 1.0) / 2.0);
	end
	return tmp
end
code[alpha_, beta_] := Block[{t$95$0 = N[(N[(beta - alpha), $MachinePrecision] / N[(N[(beta + alpha), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -0.95], N[(N[(N[(N[(N[(-2.0 - beta), $MachinePrecision] - beta), $MachinePrecision] / alpha), $MachinePrecision] * N[(N[(beta + 2.0), $MachinePrecision] / alpha), $MachinePrecision] + N[(N[(beta + N[(beta + 2.0), $MachinePrecision]), $MachinePrecision] / alpha), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision], N[(N[(t$95$0 + 1.0), $MachinePrecision] / 2.0), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2}\\
\mathbf{if}\;t_0 \leq -0.95:\\
\;\;\;\;\frac{\mathsf{fma}\left(\frac{\left(-2 - \beta\right) - \beta}{\alpha}, \frac{\beta + 2}{\alpha}, \frac{\beta + \left(\beta + 2\right)}{\alpha}\right)}{2}\\

\mathbf{else}:\\
\;\;\;\;\frac{t_0 + 1}{2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) 2)) < -0.94999999999999996

    1. Initial program 7.6%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative7.6%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified7.6%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in alpha around -inf 95.8%

      \[\leadsto \frac{\color{blue}{-1 \cdot \frac{-1 \cdot \beta - \left(\beta + 2\right)}{\alpha} + -1 \cdot \frac{{\left(\beta + 2\right)}^{2} + \beta \cdot \left(\beta + 2\right)}{{\alpha}^{2}}}}{2} \]
    5. Simplified99.7%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{\left(-2 - \beta\right) - \beta}{\alpha}, \frac{2 + \beta}{\alpha}, \frac{\beta + \left(2 + \beta\right)}{\alpha}\right)}}{2} \]

    if -0.94999999999999996 < (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) 2))

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.95:\\ \;\;\;\;\frac{\mathsf{fma}\left(\frac{\left(-2 - \beta\right) - \beta}{\alpha}, \frac{\beta + 2}{\alpha}, \frac{\beta + \left(\beta + 2\right)}{\alpha}\right)}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}\\ \end{array} \]

Alternative 2: 99.6% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2}\\ \mathbf{if}\;t_0 \leq -0.99999998:\\ \;\;\;\;\frac{\frac{\beta + \left(\beta + 2\right)}{\alpha}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{t_0 + 1}{2}\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (let* ((t_0 (/ (- beta alpha) (+ (+ beta alpha) 2.0))))
   (if (<= t_0 -0.99999998)
     (/ (/ (+ beta (+ beta 2.0)) alpha) 2.0)
     (/ (+ t_0 1.0) 2.0))))
double code(double alpha, double beta) {
	double t_0 = (beta - alpha) / ((beta + alpha) + 2.0);
	double tmp;
	if (t_0 <= -0.99999998) {
		tmp = ((beta + (beta + 2.0)) / alpha) / 2.0;
	} else {
		tmp = (t_0 + 1.0) / 2.0;
	}
	return tmp;
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (beta - alpha) / ((beta + alpha) + 2.0d0)
    if (t_0 <= (-0.99999998d0)) then
        tmp = ((beta + (beta + 2.0d0)) / alpha) / 2.0d0
    else
        tmp = (t_0 + 1.0d0) / 2.0d0
    end if
    code = tmp
end function
public static double code(double alpha, double beta) {
	double t_0 = (beta - alpha) / ((beta + alpha) + 2.0);
	double tmp;
	if (t_0 <= -0.99999998) {
		tmp = ((beta + (beta + 2.0)) / alpha) / 2.0;
	} else {
		tmp = (t_0 + 1.0) / 2.0;
	}
	return tmp;
}
def code(alpha, beta):
	t_0 = (beta - alpha) / ((beta + alpha) + 2.0)
	tmp = 0
	if t_0 <= -0.99999998:
		tmp = ((beta + (beta + 2.0)) / alpha) / 2.0
	else:
		tmp = (t_0 + 1.0) / 2.0
	return tmp
function code(alpha, beta)
	t_0 = Float64(Float64(beta - alpha) / Float64(Float64(beta + alpha) + 2.0))
	tmp = 0.0
	if (t_0 <= -0.99999998)
		tmp = Float64(Float64(Float64(beta + Float64(beta + 2.0)) / alpha) / 2.0);
	else
		tmp = Float64(Float64(t_0 + 1.0) / 2.0);
	end
	return tmp
end
function tmp_2 = code(alpha, beta)
	t_0 = (beta - alpha) / ((beta + alpha) + 2.0);
	tmp = 0.0;
	if (t_0 <= -0.99999998)
		tmp = ((beta + (beta + 2.0)) / alpha) / 2.0;
	else
		tmp = (t_0 + 1.0) / 2.0;
	end
	tmp_2 = tmp;
end
code[alpha_, beta_] := Block[{t$95$0 = N[(N[(beta - alpha), $MachinePrecision] / N[(N[(beta + alpha), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -0.99999998], N[(N[(N[(beta + N[(beta + 2.0), $MachinePrecision]), $MachinePrecision] / alpha), $MachinePrecision] / 2.0), $MachinePrecision], N[(N[(t$95$0 + 1.0), $MachinePrecision] / 2.0), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2}\\
\mathbf{if}\;t_0 \leq -0.99999998:\\
\;\;\;\;\frac{\frac{\beta + \left(\beta + 2\right)}{\alpha}}{2}\\

\mathbf{else}:\\
\;\;\;\;\frac{t_0 + 1}{2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) 2)) < -0.999999980000000011

    1. Initial program 6.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative6.0%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified6.0%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in alpha around -inf 99.9%

      \[\leadsto \frac{\color{blue}{-1 \cdot \frac{-1 \cdot \beta - \left(\beta + 2\right)}{\alpha}}}{2} \]
    5. Step-by-step derivation
      1. associate-*r/99.9%

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

        \[\leadsto \frac{\frac{-1 \cdot \color{blue}{\left(-1 \cdot \beta + \left(-\left(\beta + 2\right)\right)\right)}}{\alpha}}{2} \]
      3. mul-1-neg99.9%

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

        \[\leadsto \frac{\frac{\color{blue}{-1 \cdot \left(-1 \cdot \beta\right) + -1 \cdot \left(-1 \cdot \left(\beta + 2\right)\right)}}{\alpha}}{2} \]
      5. neg-mul-199.9%

        \[\leadsto \frac{\frac{\color{blue}{\left(--1 \cdot \beta\right)} + -1 \cdot \left(-1 \cdot \left(\beta + 2\right)\right)}{\alpha}}{2} \]
      6. mul-1-neg99.9%

        \[\leadsto \frac{\frac{\left(-\color{blue}{\left(-\beta\right)}\right) + -1 \cdot \left(-1 \cdot \left(\beta + 2\right)\right)}{\alpha}}{2} \]
      7. remove-double-neg99.9%

        \[\leadsto \frac{\frac{\color{blue}{\beta} + -1 \cdot \left(-1 \cdot \left(\beta + 2\right)\right)}{\alpha}}{2} \]
      8. neg-mul-199.9%

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

        \[\leadsto \frac{\frac{\beta + \left(-\color{blue}{\left(-\left(\beta + 2\right)\right)}\right)}{\alpha}}{2} \]
      10. remove-double-neg99.9%

        \[\leadsto \frac{\frac{\beta + \color{blue}{\left(\beta + 2\right)}}{\alpha}}{2} \]
      11. +-commutative99.9%

        \[\leadsto \frac{\frac{\beta + \color{blue}{\left(2 + \beta\right)}}{\alpha}}{2} \]
    6. Simplified99.9%

      \[\leadsto \frac{\color{blue}{\frac{\beta + \left(2 + \beta\right)}{\alpha}}}{2} \]

    if -0.999999980000000011 < (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) 2))

    1. Initial program 99.6%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.99999998:\\ \;\;\;\;\frac{\frac{\beta + \left(\beta + 2\right)}{\alpha}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}\\ \end{array} \]

Alternative 3: 68.7% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1 + \beta \cdot 0.5}{2}\\ t_1 := \frac{\frac{2}{\alpha}}{2}\\ \mathbf{if}\;\beta \leq -1.12 \cdot 10^{-94}:\\ \;\;\;\;t_0\\ \mathbf{elif}\;\beta \leq -4 \cdot 10^{-115}:\\ \;\;\;\;t_1\\ \mathbf{elif}\;\beta \leq 1.05 \cdot 10^{-299}:\\ \;\;\;\;t_0\\ \mathbf{elif}\;\beta \leq 1.05 \cdot 10^{-231}:\\ \;\;\;\;t_1\\ \mathbf{elif}\;\beta \leq 2:\\ \;\;\;\;t_0\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (let* ((t_0 (/ (+ 1.0 (* beta 0.5)) 2.0)) (t_1 (/ (/ 2.0 alpha) 2.0)))
   (if (<= beta -1.12e-94)
     t_0
     (if (<= beta -4e-115)
       t_1
       (if (<= beta 1.05e-299)
         t_0
         (if (<= beta 1.05e-231) t_1 (if (<= beta 2.0) t_0 1.0)))))))
double code(double alpha, double beta) {
	double t_0 = (1.0 + (beta * 0.5)) / 2.0;
	double t_1 = (2.0 / alpha) / 2.0;
	double tmp;
	if (beta <= -1.12e-94) {
		tmp = t_0;
	} else if (beta <= -4e-115) {
		tmp = t_1;
	} else if (beta <= 1.05e-299) {
		tmp = t_0;
	} else if (beta <= 1.05e-231) {
		tmp = t_1;
	} else if (beta <= 2.0) {
		tmp = t_0;
	} else {
		tmp = 1.0;
	}
	return tmp;
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = (1.0d0 + (beta * 0.5d0)) / 2.0d0
    t_1 = (2.0d0 / alpha) / 2.0d0
    if (beta <= (-1.12d-94)) then
        tmp = t_0
    else if (beta <= (-4d-115)) then
        tmp = t_1
    else if (beta <= 1.05d-299) then
        tmp = t_0
    else if (beta <= 1.05d-231) then
        tmp = t_1
    else if (beta <= 2.0d0) then
        tmp = t_0
    else
        tmp = 1.0d0
    end if
    code = tmp
end function
public static double code(double alpha, double beta) {
	double t_0 = (1.0 + (beta * 0.5)) / 2.0;
	double t_1 = (2.0 / alpha) / 2.0;
	double tmp;
	if (beta <= -1.12e-94) {
		tmp = t_0;
	} else if (beta <= -4e-115) {
		tmp = t_1;
	} else if (beta <= 1.05e-299) {
		tmp = t_0;
	} else if (beta <= 1.05e-231) {
		tmp = t_1;
	} else if (beta <= 2.0) {
		tmp = t_0;
	} else {
		tmp = 1.0;
	}
	return tmp;
}
def code(alpha, beta):
	t_0 = (1.0 + (beta * 0.5)) / 2.0
	t_1 = (2.0 / alpha) / 2.0
	tmp = 0
	if beta <= -1.12e-94:
		tmp = t_0
	elif beta <= -4e-115:
		tmp = t_1
	elif beta <= 1.05e-299:
		tmp = t_0
	elif beta <= 1.05e-231:
		tmp = t_1
	elif beta <= 2.0:
		tmp = t_0
	else:
		tmp = 1.0
	return tmp
function code(alpha, beta)
	t_0 = Float64(Float64(1.0 + Float64(beta * 0.5)) / 2.0)
	t_1 = Float64(Float64(2.0 / alpha) / 2.0)
	tmp = 0.0
	if (beta <= -1.12e-94)
		tmp = t_0;
	elseif (beta <= -4e-115)
		tmp = t_1;
	elseif (beta <= 1.05e-299)
		tmp = t_0;
	elseif (beta <= 1.05e-231)
		tmp = t_1;
	elseif (beta <= 2.0)
		tmp = t_0;
	else
		tmp = 1.0;
	end
	return tmp
end
function tmp_2 = code(alpha, beta)
	t_0 = (1.0 + (beta * 0.5)) / 2.0;
	t_1 = (2.0 / alpha) / 2.0;
	tmp = 0.0;
	if (beta <= -1.12e-94)
		tmp = t_0;
	elseif (beta <= -4e-115)
		tmp = t_1;
	elseif (beta <= 1.05e-299)
		tmp = t_0;
	elseif (beta <= 1.05e-231)
		tmp = t_1;
	elseif (beta <= 2.0)
		tmp = t_0;
	else
		tmp = 1.0;
	end
	tmp_2 = tmp;
end
code[alpha_, beta_] := Block[{t$95$0 = N[(N[(1.0 + N[(beta * 0.5), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision]}, Block[{t$95$1 = N[(N[(2.0 / alpha), $MachinePrecision] / 2.0), $MachinePrecision]}, If[LessEqual[beta, -1.12e-94], t$95$0, If[LessEqual[beta, -4e-115], t$95$1, If[LessEqual[beta, 1.05e-299], t$95$0, If[LessEqual[beta, 1.05e-231], t$95$1, If[LessEqual[beta, 2.0], t$95$0, 1.0]]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{1 + \beta \cdot 0.5}{2}\\
t_1 := \frac{\frac{2}{\alpha}}{2}\\
\mathbf{if}\;\beta \leq -1.12 \cdot 10^{-94}:\\
\;\;\;\;t_0\\

\mathbf{elif}\;\beta \leq -4 \cdot 10^{-115}:\\
\;\;\;\;t_1\\

\mathbf{elif}\;\beta \leq 1.05 \cdot 10^{-299}:\\
\;\;\;\;t_0\\

\mathbf{elif}\;\beta \leq 1.05 \cdot 10^{-231}:\\
\;\;\;\;t_1\\

\mathbf{elif}\;\beta \leq 2:\\
\;\;\;\;t_0\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if beta < -1.12e-94 or -4.0000000000000002e-115 < beta < 1.05000000000000005e-299 or 1.04999999999999995e-231 < beta < 2

    1. Initial program 68.9%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative68.9%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified68.9%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in alpha around 0 66.3%

      \[\leadsto \frac{\color{blue}{\frac{\beta}{\beta + 2}} + 1}{2} \]
    5. Taylor expanded in beta around 0 64.7%

      \[\leadsto \frac{\color{blue}{0.5 \cdot \beta} + 1}{2} \]
    6. Step-by-step derivation
      1. *-commutative64.7%

        \[\leadsto \frac{\color{blue}{\beta \cdot 0.5} + 1}{2} \]
    7. Simplified64.7%

      \[\leadsto \frac{\color{blue}{\beta \cdot 0.5} + 1}{2} \]

    if -1.12e-94 < beta < -4.0000000000000002e-115 or 1.05000000000000005e-299 < beta < 1.04999999999999995e-231

    1. Initial program 26.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative26.0%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified26.0%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in beta around 0 26.0%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{2 + \alpha}}}{2} \]
    5. Step-by-step derivation
      1. +-commutative26.0%

        \[\leadsto \frac{1 - \frac{\alpha}{\color{blue}{\alpha + 2}}}{2} \]
    6. Simplified26.0%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{\alpha + 2}}}{2} \]
    7. Taylor expanded in alpha around inf 79.8%

      \[\leadsto \frac{\color{blue}{\frac{2}{\alpha}}}{2} \]

    if 2 < beta

    1. Initial program 88.4%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative88.4%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified88.4%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in beta around inf 87.4%

      \[\leadsto \frac{\color{blue}{2}}{2} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification74.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\beta \leq -1.12 \cdot 10^{-94}:\\ \;\;\;\;\frac{1 + \beta \cdot 0.5}{2}\\ \mathbf{elif}\;\beta \leq -4 \cdot 10^{-115}:\\ \;\;\;\;\frac{\frac{2}{\alpha}}{2}\\ \mathbf{elif}\;\beta \leq 1.05 \cdot 10^{-299}:\\ \;\;\;\;\frac{1 + \beta \cdot 0.5}{2}\\ \mathbf{elif}\;\beta \leq 1.05 \cdot 10^{-231}:\\ \;\;\;\;\frac{\frac{2}{\alpha}}{2}\\ \mathbf{elif}\;\beta \leq 2:\\ \;\;\;\;\frac{1 + \beta \cdot 0.5}{2}\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]

Alternative 4: 69.2% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1 + \beta \cdot 0.5}{2}\\ t_1 := \frac{\frac{2}{\alpha}}{2}\\ \mathbf{if}\;\beta \leq -1.85 \cdot 10^{-96}:\\ \;\;\;\;t_0\\ \mathbf{elif}\;\beta \leq -2.2 \cdot 10^{-114}:\\ \;\;\;\;t_1\\ \mathbf{elif}\;\beta \leq 3.1 \cdot 10^{-299}:\\ \;\;\;\;t_0\\ \mathbf{elif}\;\beta \leq 10^{-231}:\\ \;\;\;\;t_1\\ \mathbf{elif}\;\beta \leq 2:\\ \;\;\;\;t_0\\ \mathbf{else}:\\ \;\;\;\;\frac{2 - \frac{2}{\beta}}{2}\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (let* ((t_0 (/ (+ 1.0 (* beta 0.5)) 2.0)) (t_1 (/ (/ 2.0 alpha) 2.0)))
   (if (<= beta -1.85e-96)
     t_0
     (if (<= beta -2.2e-114)
       t_1
       (if (<= beta 3.1e-299)
         t_0
         (if (<= beta 1e-231)
           t_1
           (if (<= beta 2.0) t_0 (/ (- 2.0 (/ 2.0 beta)) 2.0))))))))
double code(double alpha, double beta) {
	double t_0 = (1.0 + (beta * 0.5)) / 2.0;
	double t_1 = (2.0 / alpha) / 2.0;
	double tmp;
	if (beta <= -1.85e-96) {
		tmp = t_0;
	} else if (beta <= -2.2e-114) {
		tmp = t_1;
	} else if (beta <= 3.1e-299) {
		tmp = t_0;
	} else if (beta <= 1e-231) {
		tmp = t_1;
	} else if (beta <= 2.0) {
		tmp = t_0;
	} else {
		tmp = (2.0 - (2.0 / beta)) / 2.0;
	}
	return tmp;
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = (1.0d0 + (beta * 0.5d0)) / 2.0d0
    t_1 = (2.0d0 / alpha) / 2.0d0
    if (beta <= (-1.85d-96)) then
        tmp = t_0
    else if (beta <= (-2.2d-114)) then
        tmp = t_1
    else if (beta <= 3.1d-299) then
        tmp = t_0
    else if (beta <= 1d-231) then
        tmp = t_1
    else if (beta <= 2.0d0) then
        tmp = t_0
    else
        tmp = (2.0d0 - (2.0d0 / beta)) / 2.0d0
    end if
    code = tmp
end function
public static double code(double alpha, double beta) {
	double t_0 = (1.0 + (beta * 0.5)) / 2.0;
	double t_1 = (2.0 / alpha) / 2.0;
	double tmp;
	if (beta <= -1.85e-96) {
		tmp = t_0;
	} else if (beta <= -2.2e-114) {
		tmp = t_1;
	} else if (beta <= 3.1e-299) {
		tmp = t_0;
	} else if (beta <= 1e-231) {
		tmp = t_1;
	} else if (beta <= 2.0) {
		tmp = t_0;
	} else {
		tmp = (2.0 - (2.0 / beta)) / 2.0;
	}
	return tmp;
}
def code(alpha, beta):
	t_0 = (1.0 + (beta * 0.5)) / 2.0
	t_1 = (2.0 / alpha) / 2.0
	tmp = 0
	if beta <= -1.85e-96:
		tmp = t_0
	elif beta <= -2.2e-114:
		tmp = t_1
	elif beta <= 3.1e-299:
		tmp = t_0
	elif beta <= 1e-231:
		tmp = t_1
	elif beta <= 2.0:
		tmp = t_0
	else:
		tmp = (2.0 - (2.0 / beta)) / 2.0
	return tmp
function code(alpha, beta)
	t_0 = Float64(Float64(1.0 + Float64(beta * 0.5)) / 2.0)
	t_1 = Float64(Float64(2.0 / alpha) / 2.0)
	tmp = 0.0
	if (beta <= -1.85e-96)
		tmp = t_0;
	elseif (beta <= -2.2e-114)
		tmp = t_1;
	elseif (beta <= 3.1e-299)
		tmp = t_0;
	elseif (beta <= 1e-231)
		tmp = t_1;
	elseif (beta <= 2.0)
		tmp = t_0;
	else
		tmp = Float64(Float64(2.0 - Float64(2.0 / beta)) / 2.0);
	end
	return tmp
end
function tmp_2 = code(alpha, beta)
	t_0 = (1.0 + (beta * 0.5)) / 2.0;
	t_1 = (2.0 / alpha) / 2.0;
	tmp = 0.0;
	if (beta <= -1.85e-96)
		tmp = t_0;
	elseif (beta <= -2.2e-114)
		tmp = t_1;
	elseif (beta <= 3.1e-299)
		tmp = t_0;
	elseif (beta <= 1e-231)
		tmp = t_1;
	elseif (beta <= 2.0)
		tmp = t_0;
	else
		tmp = (2.0 - (2.0 / beta)) / 2.0;
	end
	tmp_2 = tmp;
end
code[alpha_, beta_] := Block[{t$95$0 = N[(N[(1.0 + N[(beta * 0.5), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision]}, Block[{t$95$1 = N[(N[(2.0 / alpha), $MachinePrecision] / 2.0), $MachinePrecision]}, If[LessEqual[beta, -1.85e-96], t$95$0, If[LessEqual[beta, -2.2e-114], t$95$1, If[LessEqual[beta, 3.1e-299], t$95$0, If[LessEqual[beta, 1e-231], t$95$1, If[LessEqual[beta, 2.0], t$95$0, N[(N[(2.0 - N[(2.0 / beta), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision]]]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{1 + \beta \cdot 0.5}{2}\\
t_1 := \frac{\frac{2}{\alpha}}{2}\\
\mathbf{if}\;\beta \leq -1.85 \cdot 10^{-96}:\\
\;\;\;\;t_0\\

\mathbf{elif}\;\beta \leq -2.2 \cdot 10^{-114}:\\
\;\;\;\;t_1\\

\mathbf{elif}\;\beta \leq 3.1 \cdot 10^{-299}:\\
\;\;\;\;t_0\\

\mathbf{elif}\;\beta \leq 10^{-231}:\\
\;\;\;\;t_1\\

\mathbf{elif}\;\beta \leq 2:\\
\;\;\;\;t_0\\

\mathbf{else}:\\
\;\;\;\;\frac{2 - \frac{2}{\beta}}{2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if beta < -1.84999999999999993e-96 or -2.20000000000000011e-114 < beta < 3.1e-299 or 9.9999999999999999e-232 < beta < 2

    1. Initial program 68.9%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative68.9%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified68.9%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in alpha around 0 66.3%

      \[\leadsto \frac{\color{blue}{\frac{\beta}{\beta + 2}} + 1}{2} \]
    5. Taylor expanded in beta around 0 64.7%

      \[\leadsto \frac{\color{blue}{0.5 \cdot \beta} + 1}{2} \]
    6. Step-by-step derivation
      1. *-commutative64.7%

        \[\leadsto \frac{\color{blue}{\beta \cdot 0.5} + 1}{2} \]
    7. Simplified64.7%

      \[\leadsto \frac{\color{blue}{\beta \cdot 0.5} + 1}{2} \]

    if -1.84999999999999993e-96 < beta < -2.20000000000000011e-114 or 3.1e-299 < beta < 9.9999999999999999e-232

    1. Initial program 26.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative26.0%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified26.0%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in beta around 0 26.0%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{2 + \alpha}}}{2} \]
    5. Step-by-step derivation
      1. +-commutative26.0%

        \[\leadsto \frac{1 - \frac{\alpha}{\color{blue}{\alpha + 2}}}{2} \]
    6. Simplified26.0%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{\alpha + 2}}}{2} \]
    7. Taylor expanded in alpha around inf 79.8%

      \[\leadsto \frac{\color{blue}{\frac{2}{\alpha}}}{2} \]

    if 2 < beta

    1. Initial program 88.4%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative88.4%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified88.4%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in alpha around 0 88.2%

      \[\leadsto \frac{\color{blue}{\frac{\beta}{\beta + 2}} + 1}{2} \]
    5. Taylor expanded in beta around inf 87.4%

      \[\leadsto \frac{\color{blue}{2 - 2 \cdot \frac{1}{\beta}}}{2} \]
    6. Step-by-step derivation
      1. associate-*r/87.4%

        \[\leadsto \frac{2 - \color{blue}{\frac{2 \cdot 1}{\beta}}}{2} \]
      2. metadata-eval87.4%

        \[\leadsto \frac{2 - \frac{\color{blue}{2}}{\beta}}{2} \]
    7. Simplified87.4%

      \[\leadsto \frac{\color{blue}{2 - \frac{2}{\beta}}}{2} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification74.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\beta \leq -1.85 \cdot 10^{-96}:\\ \;\;\;\;\frac{1 + \beta \cdot 0.5}{2}\\ \mathbf{elif}\;\beta \leq -2.2 \cdot 10^{-114}:\\ \;\;\;\;\frac{\frac{2}{\alpha}}{2}\\ \mathbf{elif}\;\beta \leq 3.1 \cdot 10^{-299}:\\ \;\;\;\;\frac{1 + \beta \cdot 0.5}{2}\\ \mathbf{elif}\;\beta \leq 10^{-231}:\\ \;\;\;\;\frac{\frac{2}{\alpha}}{2}\\ \mathbf{elif}\;\beta \leq 2:\\ \;\;\;\;\frac{1 + \beta \cdot 0.5}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{2 - \frac{2}{\beta}}{2}\\ \end{array} \]

Alternative 5: 68.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\frac{2}{\alpha}}{2}\\ \mathbf{if}\;\beta \leq -1.25 \cdot 10^{-95}:\\ \;\;\;\;0.5\\ \mathbf{elif}\;\beta \leq -1.4 \cdot 10^{-115}:\\ \;\;\;\;t_0\\ \mathbf{elif}\;\beta \leq 2.3 \cdot 10^{-299}:\\ \;\;\;\;0.5\\ \mathbf{elif}\;\beta \leq 1.75 \cdot 10^{-231}:\\ \;\;\;\;t_0\\ \mathbf{elif}\;\beta \leq 2:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (let* ((t_0 (/ (/ 2.0 alpha) 2.0)))
   (if (<= beta -1.25e-95)
     0.5
     (if (<= beta -1.4e-115)
       t_0
       (if (<= beta 2.3e-299)
         0.5
         (if (<= beta 1.75e-231) t_0 (if (<= beta 2.0) 0.5 1.0)))))))
double code(double alpha, double beta) {
	double t_0 = (2.0 / alpha) / 2.0;
	double tmp;
	if (beta <= -1.25e-95) {
		tmp = 0.5;
	} else if (beta <= -1.4e-115) {
		tmp = t_0;
	} else if (beta <= 2.3e-299) {
		tmp = 0.5;
	} else if (beta <= 1.75e-231) {
		tmp = t_0;
	} else if (beta <= 2.0) {
		tmp = 0.5;
	} else {
		tmp = 1.0;
	}
	return tmp;
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (2.0d0 / alpha) / 2.0d0
    if (beta <= (-1.25d-95)) then
        tmp = 0.5d0
    else if (beta <= (-1.4d-115)) then
        tmp = t_0
    else if (beta <= 2.3d-299) then
        tmp = 0.5d0
    else if (beta <= 1.75d-231) then
        tmp = t_0
    else if (beta <= 2.0d0) then
        tmp = 0.5d0
    else
        tmp = 1.0d0
    end if
    code = tmp
end function
public static double code(double alpha, double beta) {
	double t_0 = (2.0 / alpha) / 2.0;
	double tmp;
	if (beta <= -1.25e-95) {
		tmp = 0.5;
	} else if (beta <= -1.4e-115) {
		tmp = t_0;
	} else if (beta <= 2.3e-299) {
		tmp = 0.5;
	} else if (beta <= 1.75e-231) {
		tmp = t_0;
	} else if (beta <= 2.0) {
		tmp = 0.5;
	} else {
		tmp = 1.0;
	}
	return tmp;
}
def code(alpha, beta):
	t_0 = (2.0 / alpha) / 2.0
	tmp = 0
	if beta <= -1.25e-95:
		tmp = 0.5
	elif beta <= -1.4e-115:
		tmp = t_0
	elif beta <= 2.3e-299:
		tmp = 0.5
	elif beta <= 1.75e-231:
		tmp = t_0
	elif beta <= 2.0:
		tmp = 0.5
	else:
		tmp = 1.0
	return tmp
function code(alpha, beta)
	t_0 = Float64(Float64(2.0 / alpha) / 2.0)
	tmp = 0.0
	if (beta <= -1.25e-95)
		tmp = 0.5;
	elseif (beta <= -1.4e-115)
		tmp = t_0;
	elseif (beta <= 2.3e-299)
		tmp = 0.5;
	elseif (beta <= 1.75e-231)
		tmp = t_0;
	elseif (beta <= 2.0)
		tmp = 0.5;
	else
		tmp = 1.0;
	end
	return tmp
end
function tmp_2 = code(alpha, beta)
	t_0 = (2.0 / alpha) / 2.0;
	tmp = 0.0;
	if (beta <= -1.25e-95)
		tmp = 0.5;
	elseif (beta <= -1.4e-115)
		tmp = t_0;
	elseif (beta <= 2.3e-299)
		tmp = 0.5;
	elseif (beta <= 1.75e-231)
		tmp = t_0;
	elseif (beta <= 2.0)
		tmp = 0.5;
	else
		tmp = 1.0;
	end
	tmp_2 = tmp;
end
code[alpha_, beta_] := Block[{t$95$0 = N[(N[(2.0 / alpha), $MachinePrecision] / 2.0), $MachinePrecision]}, If[LessEqual[beta, -1.25e-95], 0.5, If[LessEqual[beta, -1.4e-115], t$95$0, If[LessEqual[beta, 2.3e-299], 0.5, If[LessEqual[beta, 1.75e-231], t$95$0, If[LessEqual[beta, 2.0], 0.5, 1.0]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\frac{2}{\alpha}}{2}\\
\mathbf{if}\;\beta \leq -1.25 \cdot 10^{-95}:\\
\;\;\;\;0.5\\

\mathbf{elif}\;\beta \leq -1.4 \cdot 10^{-115}:\\
\;\;\;\;t_0\\

\mathbf{elif}\;\beta \leq 2.3 \cdot 10^{-299}:\\
\;\;\;\;0.5\\

\mathbf{elif}\;\beta \leq 1.75 \cdot 10^{-231}:\\
\;\;\;\;t_0\\

\mathbf{elif}\;\beta \leq 2:\\
\;\;\;\;0.5\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if beta < -1.2499999999999999e-95 or -1.39999999999999994e-115 < beta < 2.3000000000000001e-299 or 1.7500000000000001e-231 < beta < 2

    1. Initial program 68.9%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative68.9%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified68.9%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in beta around 0 66.7%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{2 + \alpha}}}{2} \]
    5. Step-by-step derivation
      1. +-commutative66.7%

        \[\leadsto \frac{1 - \frac{\alpha}{\color{blue}{\alpha + 2}}}{2} \]
    6. Simplified66.7%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{\alpha + 2}}}{2} \]
    7. Taylor expanded in alpha around 0 64.1%

      \[\leadsto \frac{\color{blue}{1}}{2} \]

    if -1.2499999999999999e-95 < beta < -1.39999999999999994e-115 or 2.3000000000000001e-299 < beta < 1.7500000000000001e-231

    1. Initial program 26.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative26.0%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified26.0%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in beta around 0 26.0%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{2 + \alpha}}}{2} \]
    5. Step-by-step derivation
      1. +-commutative26.0%

        \[\leadsto \frac{1 - \frac{\alpha}{\color{blue}{\alpha + 2}}}{2} \]
    6. Simplified26.0%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{\alpha + 2}}}{2} \]
    7. Taylor expanded in alpha around inf 79.8%

      \[\leadsto \frac{\color{blue}{\frac{2}{\alpha}}}{2} \]

    if 2 < beta

    1. Initial program 88.4%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative88.4%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified88.4%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in beta around inf 87.4%

      \[\leadsto \frac{\color{blue}{2}}{2} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification73.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\beta \leq -1.25 \cdot 10^{-95}:\\ \;\;\;\;0.5\\ \mathbf{elif}\;\beta \leq -1.4 \cdot 10^{-115}:\\ \;\;\;\;\frac{\frac{2}{\alpha}}{2}\\ \mathbf{elif}\;\beta \leq 2.3 \cdot 10^{-299}:\\ \;\;\;\;0.5\\ \mathbf{elif}\;\beta \leq 1.75 \cdot 10^{-231}:\\ \;\;\;\;\frac{\frac{2}{\alpha}}{2}\\ \mathbf{elif}\;\beta \leq 2:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]

Alternative 6: 87.6% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\alpha \leq 31.5:\\ \;\;\;\;\frac{1 + \frac{\beta}{\beta + 2}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{2}{\alpha}}{2}\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= alpha 31.5)
   (/ (+ 1.0 (/ beta (+ beta 2.0))) 2.0)
   (/ (/ 2.0 alpha) 2.0)))
double code(double alpha, double beta) {
	double tmp;
	if (alpha <= 31.5) {
		tmp = (1.0 + (beta / (beta + 2.0))) / 2.0;
	} else {
		tmp = (2.0 / alpha) / 2.0;
	}
	return tmp;
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8) :: tmp
    if (alpha <= 31.5d0) then
        tmp = (1.0d0 + (beta / (beta + 2.0d0))) / 2.0d0
    else
        tmp = (2.0d0 / alpha) / 2.0d0
    end if
    code = tmp
end function
public static double code(double alpha, double beta) {
	double tmp;
	if (alpha <= 31.5) {
		tmp = (1.0 + (beta / (beta + 2.0))) / 2.0;
	} else {
		tmp = (2.0 / alpha) / 2.0;
	}
	return tmp;
}
def code(alpha, beta):
	tmp = 0
	if alpha <= 31.5:
		tmp = (1.0 + (beta / (beta + 2.0))) / 2.0
	else:
		tmp = (2.0 / alpha) / 2.0
	return tmp
function code(alpha, beta)
	tmp = 0.0
	if (alpha <= 31.5)
		tmp = Float64(Float64(1.0 + Float64(beta / Float64(beta + 2.0))) / 2.0);
	else
		tmp = Float64(Float64(2.0 / alpha) / 2.0);
	end
	return tmp
end
function tmp_2 = code(alpha, beta)
	tmp = 0.0;
	if (alpha <= 31.5)
		tmp = (1.0 + (beta / (beta + 2.0))) / 2.0;
	else
		tmp = (2.0 / alpha) / 2.0;
	end
	tmp_2 = tmp;
end
code[alpha_, beta_] := If[LessEqual[alpha, 31.5], N[(N[(1.0 + N[(beta / N[(beta + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision], N[(N[(2.0 / alpha), $MachinePrecision] / 2.0), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\alpha \leq 31.5:\\
\;\;\;\;\frac{1 + \frac{\beta}{\beta + 2}}{2}\\

\mathbf{else}:\\
\;\;\;\;\frac{\frac{2}{\alpha}}{2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if alpha < 31.5

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in alpha around 0 99.3%

      \[\leadsto \frac{\color{blue}{\frac{\beta}{\beta + 2}} + 1}{2} \]

    if 31.5 < alpha

    1. Initial program 23.3%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative23.3%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified23.3%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in beta around 0 7.8%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{2 + \alpha}}}{2} \]
    5. Step-by-step derivation
      1. +-commutative7.8%

        \[\leadsto \frac{1 - \frac{\alpha}{\color{blue}{\alpha + 2}}}{2} \]
    6. Simplified7.8%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{\alpha + 2}}}{2} \]
    7. Taylor expanded in alpha around inf 71.3%

      \[\leadsto \frac{\color{blue}{\frac{2}{\alpha}}}{2} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification89.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\alpha \leq 31.5:\\ \;\;\;\;\frac{1 + \frac{\beta}{\beta + 2}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{2}{\alpha}}{2}\\ \end{array} \]

Alternative 7: 93.0% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\alpha \leq 31.5:\\ \;\;\;\;\frac{1 + \frac{\beta}{\beta + 2}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\beta + \left(\beta + 2\right)}{\alpha}}{2}\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= alpha 31.5)
   (/ (+ 1.0 (/ beta (+ beta 2.0))) 2.0)
   (/ (/ (+ beta (+ beta 2.0)) alpha) 2.0)))
double code(double alpha, double beta) {
	double tmp;
	if (alpha <= 31.5) {
		tmp = (1.0 + (beta / (beta + 2.0))) / 2.0;
	} else {
		tmp = ((beta + (beta + 2.0)) / alpha) / 2.0;
	}
	return tmp;
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8) :: tmp
    if (alpha <= 31.5d0) then
        tmp = (1.0d0 + (beta / (beta + 2.0d0))) / 2.0d0
    else
        tmp = ((beta + (beta + 2.0d0)) / alpha) / 2.0d0
    end if
    code = tmp
end function
public static double code(double alpha, double beta) {
	double tmp;
	if (alpha <= 31.5) {
		tmp = (1.0 + (beta / (beta + 2.0))) / 2.0;
	} else {
		tmp = ((beta + (beta + 2.0)) / alpha) / 2.0;
	}
	return tmp;
}
def code(alpha, beta):
	tmp = 0
	if alpha <= 31.5:
		tmp = (1.0 + (beta / (beta + 2.0))) / 2.0
	else:
		tmp = ((beta + (beta + 2.0)) / alpha) / 2.0
	return tmp
function code(alpha, beta)
	tmp = 0.0
	if (alpha <= 31.5)
		tmp = Float64(Float64(1.0 + Float64(beta / Float64(beta + 2.0))) / 2.0);
	else
		tmp = Float64(Float64(Float64(beta + Float64(beta + 2.0)) / alpha) / 2.0);
	end
	return tmp
end
function tmp_2 = code(alpha, beta)
	tmp = 0.0;
	if (alpha <= 31.5)
		tmp = (1.0 + (beta / (beta + 2.0))) / 2.0;
	else
		tmp = ((beta + (beta + 2.0)) / alpha) / 2.0;
	end
	tmp_2 = tmp;
end
code[alpha_, beta_] := If[LessEqual[alpha, 31.5], N[(N[(1.0 + N[(beta / N[(beta + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision], N[(N[(N[(beta + N[(beta + 2.0), $MachinePrecision]), $MachinePrecision] / alpha), $MachinePrecision] / 2.0), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\alpha \leq 31.5:\\
\;\;\;\;\frac{1 + \frac{\beta}{\beta + 2}}{2}\\

\mathbf{else}:\\
\;\;\;\;\frac{\frac{\beta + \left(\beta + 2\right)}{\alpha}}{2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if alpha < 31.5

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in alpha around 0 99.3%

      \[\leadsto \frac{\color{blue}{\frac{\beta}{\beta + 2}} + 1}{2} \]

    if 31.5 < alpha

    1. Initial program 23.3%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative23.3%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified23.3%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in alpha around -inf 83.2%

      \[\leadsto \frac{\color{blue}{-1 \cdot \frac{-1 \cdot \beta - \left(\beta + 2\right)}{\alpha}}}{2} \]
    5. Step-by-step derivation
      1. associate-*r/83.2%

        \[\leadsto \frac{\color{blue}{\frac{-1 \cdot \left(-1 \cdot \beta - \left(\beta + 2\right)\right)}{\alpha}}}{2} \]
      2. sub-neg83.2%

        \[\leadsto \frac{\frac{-1 \cdot \color{blue}{\left(-1 \cdot \beta + \left(-\left(\beta + 2\right)\right)\right)}}{\alpha}}{2} \]
      3. mul-1-neg83.2%

        \[\leadsto \frac{\frac{-1 \cdot \left(-1 \cdot \beta + \color{blue}{-1 \cdot \left(\beta + 2\right)}\right)}{\alpha}}{2} \]
      4. distribute-lft-in83.2%

        \[\leadsto \frac{\frac{\color{blue}{-1 \cdot \left(-1 \cdot \beta\right) + -1 \cdot \left(-1 \cdot \left(\beta + 2\right)\right)}}{\alpha}}{2} \]
      5. neg-mul-183.2%

        \[\leadsto \frac{\frac{\color{blue}{\left(--1 \cdot \beta\right)} + -1 \cdot \left(-1 \cdot \left(\beta + 2\right)\right)}{\alpha}}{2} \]
      6. mul-1-neg83.2%

        \[\leadsto \frac{\frac{\left(-\color{blue}{\left(-\beta\right)}\right) + -1 \cdot \left(-1 \cdot \left(\beta + 2\right)\right)}{\alpha}}{2} \]
      7. remove-double-neg83.2%

        \[\leadsto \frac{\frac{\color{blue}{\beta} + -1 \cdot \left(-1 \cdot \left(\beta + 2\right)\right)}{\alpha}}{2} \]
      8. neg-mul-183.2%

        \[\leadsto \frac{\frac{\beta + \color{blue}{\left(--1 \cdot \left(\beta + 2\right)\right)}}{\alpha}}{2} \]
      9. mul-1-neg83.2%

        \[\leadsto \frac{\frac{\beta + \left(-\color{blue}{\left(-\left(\beta + 2\right)\right)}\right)}{\alpha}}{2} \]
      10. remove-double-neg83.2%

        \[\leadsto \frac{\frac{\beta + \color{blue}{\left(\beta + 2\right)}}{\alpha}}{2} \]
      11. +-commutative83.2%

        \[\leadsto \frac{\frac{\beta + \color{blue}{\left(2 + \beta\right)}}{\alpha}}{2} \]
    6. Simplified83.2%

      \[\leadsto \frac{\color{blue}{\frac{\beta + \left(2 + \beta\right)}{\alpha}}}{2} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification93.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\alpha \leq 31.5:\\ \;\;\;\;\frac{1 + \frac{\beta}{\beta + 2}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\beta + \left(\beta + 2\right)}{\alpha}}{2}\\ \end{array} \]

Alternative 8: 71.7% accurate, 4.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\beta \leq 2:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
(FPCore (alpha beta) :precision binary64 (if (<= beta 2.0) 0.5 1.0))
double code(double alpha, double beta) {
	double tmp;
	if (beta <= 2.0) {
		tmp = 0.5;
	} else {
		tmp = 1.0;
	}
	return tmp;
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8) :: tmp
    if (beta <= 2.0d0) then
        tmp = 0.5d0
    else
        tmp = 1.0d0
    end if
    code = tmp
end function
public static double code(double alpha, double beta) {
	double tmp;
	if (beta <= 2.0) {
		tmp = 0.5;
	} else {
		tmp = 1.0;
	}
	return tmp;
}
def code(alpha, beta):
	tmp = 0
	if beta <= 2.0:
		tmp = 0.5
	else:
		tmp = 1.0
	return tmp
function code(alpha, beta)
	tmp = 0.0
	if (beta <= 2.0)
		tmp = 0.5;
	else
		tmp = 1.0;
	end
	return tmp
end
function tmp_2 = code(alpha, beta)
	tmp = 0.0;
	if (beta <= 2.0)
		tmp = 0.5;
	else
		tmp = 1.0;
	end
	tmp_2 = tmp;
end
code[alpha_, beta_] := If[LessEqual[beta, 2.0], 0.5, 1.0]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\beta \leq 2:\\
\;\;\;\;0.5\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if beta < 2

    1. Initial program 62.7%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative62.7%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified62.7%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in beta around 0 60.8%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{2 + \alpha}}}{2} \]
    5. Step-by-step derivation
      1. +-commutative60.8%

        \[\leadsto \frac{1 - \frac{\alpha}{\color{blue}{\alpha + 2}}}{2} \]
    6. Simplified60.8%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{\alpha + 2}}}{2} \]
    7. Taylor expanded in alpha around 0 58.3%

      \[\leadsto \frac{\color{blue}{1}}{2} \]

    if 2 < beta

    1. Initial program 88.4%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative88.4%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified88.4%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in beta around inf 87.4%

      \[\leadsto \frac{\color{blue}{2}}{2} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification68.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\beta \leq 2:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]

Alternative 9: 49.3% accurate, 13.0× speedup?

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

\\
0.5
\end{array}
Derivation
  1. Initial program 71.8%

    \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
  2. Step-by-step derivation
    1. +-commutative71.8%

      \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
  3. Simplified71.8%

    \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
  4. Taylor expanded in beta around 0 44.3%

    \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{2 + \alpha}}}{2} \]
  5. Step-by-step derivation
    1. +-commutative44.3%

      \[\leadsto \frac{1 - \frac{\alpha}{\color{blue}{\alpha + 2}}}{2} \]
  6. Simplified44.3%

    \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{\alpha + 2}}}{2} \]
  7. Taylor expanded in alpha around 0 43.7%

    \[\leadsto \frac{\color{blue}{1}}{2} \]
  8. Final simplification43.7%

    \[\leadsto 0.5 \]

Reproduce

?
herbie shell --seed 2023196 
(FPCore (alpha beta)
  :name "Octave 3.8, jcobi/1"
  :precision binary64
  :pre (and (> alpha -1.0) (> beta -1.0))
  (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0))