Octave 3.8, jcobi/1

Percentage Accurate: 74.2% → 99.9%
Time: 9.4s
Alternatives: 9
Speedup: 0.7×

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: 74.2% 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: 99.9% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \beta + \left(\alpha + 2\right)\\ \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.99996:\\ \;\;\;\;\frac{\beta + \mathsf{fma}\left(\mathsf{fma}\left(-0.5, \beta, -1\right), \frac{\beta + \left(\beta + 2\right)}{\alpha}, 1\right)}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\frac{1 + \left(\frac{\beta}{t\_0} - \frac{\alpha}{t\_0}\right)}{2}\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (let* ((t_0 (+ beta (+ alpha 2.0))))
   (if (<= (/ (- beta alpha) (+ (+ beta alpha) 2.0)) -0.99996)
     (/
      (+ beta (fma (fma -0.5 beta -1.0) (/ (+ beta (+ beta 2.0)) alpha) 1.0))
      alpha)
     (/ (+ 1.0 (- (/ beta t_0) (/ alpha t_0))) 2.0))))
double code(double alpha, double beta) {
	double t_0 = beta + (alpha + 2.0);
	double tmp;
	if (((beta - alpha) / ((beta + alpha) + 2.0)) <= -0.99996) {
		tmp = (beta + fma(fma(-0.5, beta, -1.0), ((beta + (beta + 2.0)) / alpha), 1.0)) / alpha;
	} else {
		tmp = (1.0 + ((beta / t_0) - (alpha / t_0))) / 2.0;
	}
	return tmp;
}
function code(alpha, beta)
	t_0 = Float64(beta + Float64(alpha + 2.0))
	tmp = 0.0
	if (Float64(Float64(beta - alpha) / Float64(Float64(beta + alpha) + 2.0)) <= -0.99996)
		tmp = Float64(Float64(beta + fma(fma(-0.5, beta, -1.0), Float64(Float64(beta + Float64(beta + 2.0)) / alpha), 1.0)) / alpha);
	else
		tmp = Float64(Float64(1.0 + Float64(Float64(beta / t_0) - Float64(alpha / t_0))) / 2.0);
	end
	return tmp
end
code[alpha_, beta_] := Block[{t$95$0 = N[(beta + N[(alpha + 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(beta - alpha), $MachinePrecision] / N[(N[(beta + alpha), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], -0.99996], N[(N[(beta + N[(N[(-0.5 * beta + -1.0), $MachinePrecision] * N[(N[(beta + N[(beta + 2.0), $MachinePrecision]), $MachinePrecision] / alpha), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision] / alpha), $MachinePrecision], N[(N[(1.0 + N[(N[(beta / t$95$0), $MachinePrecision] - N[(alpha / t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \beta + \left(\alpha + 2\right)\\
\mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.99996:\\
\;\;\;\;\frac{\beta + \mathsf{fma}\left(\mathsf{fma}\left(-0.5, \beta, -1\right), \frac{\beta + \left(\beta + 2\right)}{\alpha}, 1\right)}{\alpha}\\

\mathbf{else}:\\
\;\;\;\;\frac{1 + \left(\frac{\beta}{t\_0} - \frac{\alpha}{t\_0}\right)}{2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) < -0.99995999999999996

    1. Initial program 6.9%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\alpha + \beta\right)} + 2} + 1}{2} \]
      2. lift-+.f64N/A

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\alpha + \beta\right) + 2}} + 1}{2} \]
      3. flip--N/A

        \[\leadsto \frac{\frac{\color{blue}{\frac{\beta \cdot \beta - \alpha \cdot \alpha}{\beta + \alpha}}}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
      4. +-commutativeN/A

        \[\leadsto \frac{\frac{\frac{\beta \cdot \beta - \alpha \cdot \alpha}{\color{blue}{\alpha + \beta}}}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
      5. lift-+.f64N/A

        \[\leadsto \frac{\frac{\frac{\beta \cdot \beta - \alpha \cdot \alpha}{\color{blue}{\alpha + \beta}}}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
      6. associate-/l/N/A

        \[\leadsto \frac{\color{blue}{\frac{\beta \cdot \beta - \alpha \cdot \alpha}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)}} + 1}{2} \]
      7. lower-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\beta \cdot \beta - \alpha \cdot \alpha}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)}} + 1}{2} \]
      8. sqr-negN/A

        \[\leadsto \frac{\frac{\beta \cdot \beta - \color{blue}{\left(\mathsf{neg}\left(\alpha\right)\right) \cdot \left(\mathsf{neg}\left(\alpha\right)\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      9. difference-of-squaresN/A

        \[\leadsto \frac{\frac{\color{blue}{\left(\beta + \left(\mathsf{neg}\left(\alpha\right)\right)\right) \cdot \left(\beta - \left(\mathsf{neg}\left(\alpha\right)\right)\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      10. sub-negN/A

        \[\leadsto \frac{\frac{\color{blue}{\left(\beta - \alpha\right)} \cdot \left(\beta - \left(\mathsf{neg}\left(\alpha\right)\right)\right)}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      11. lift--.f64N/A

        \[\leadsto \frac{\frac{\color{blue}{\left(\beta - \alpha\right)} \cdot \left(\beta - \left(\mathsf{neg}\left(\alpha\right)\right)\right)}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      12. sub-negN/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \color{blue}{\left(\beta + \left(\mathsf{neg}\left(\left(\mathsf{neg}\left(\alpha\right)\right)\right)\right)\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      13. remove-double-negN/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \color{blue}{\alpha}\right)}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      14. +-commutativeN/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \color{blue}{\left(\alpha + \beta\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      15. lift-+.f64N/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \color{blue}{\left(\alpha + \beta\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      16. lower-*.f64N/A

        \[\leadsto \frac{\frac{\color{blue}{\left(\beta - \alpha\right) \cdot \left(\alpha + \beta\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      17. lift-+.f64N/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \color{blue}{\left(\alpha + \beta\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      18. +-commutativeN/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \color{blue}{\left(\beta + \alpha\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      19. lower-+.f64N/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \color{blue}{\left(\beta + \alpha\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      20. lower-*.f642.8

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}{\color{blue}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)}} + 1}{2} \]
      21. lift-+.f64N/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}{\color{blue}{\left(\left(\alpha + \beta\right) + 2\right)} \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      22. lift-+.f64N/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}{\left(\color{blue}{\left(\alpha + \beta\right)} + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      23. +-commutativeN/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}{\left(\color{blue}{\left(\beta + \alpha\right)} + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      24. associate-+l+N/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}{\color{blue}{\left(\beta + \left(\alpha + 2\right)\right)} \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      25. lower-+.f64N/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}{\color{blue}{\left(\beta + \left(\alpha + 2\right)\right)} \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      26. lower-+.f642.8

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}{\left(\beta + \color{blue}{\left(\alpha + 2\right)}\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      27. lift-+.f64N/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}{\left(\beta + \left(\alpha + 2\right)\right) \cdot \color{blue}{\left(\alpha + \beta\right)}} + 1}{2} \]
    4. Applied rewrites2.8%

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

      \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(2 + 2 \cdot \beta\right) + \frac{1}{2} \cdot \frac{-1 \cdot {\left(2 + \beta\right)}^{2} - \beta \cdot \left(2 + \beta\right)}{\alpha}}{\alpha}} \]
    6. Applied rewrites99.8%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\mathsf{fma}\left(-0.5, \beta, -1\right), \frac{\beta + \left(2 + \beta\right)}{\alpha}, 1\right) + \beta}{\alpha}} \]

    if -0.99995999999999996 < (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64)))

    1. Initial program 99.8%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\alpha + \beta\right)} + 2} + 1}{2} \]
      2. lift-+.f64N/A

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\alpha + \beta\right) + 2}} + 1}{2} \]
      3. div-subN/A

        \[\leadsto \frac{\color{blue}{\left(\frac{\beta}{\left(\alpha + \beta\right) + 2} - \frac{\alpha}{\left(\alpha + \beta\right) + 2}\right)} + 1}{2} \]
      4. lower--.f64N/A

        \[\leadsto \frac{\color{blue}{\left(\frac{\beta}{\left(\alpha + \beta\right) + 2} - \frac{\alpha}{\left(\alpha + \beta\right) + 2}\right)} + 1}{2} \]
      5. lower-/.f64N/A

        \[\leadsto \frac{\left(\color{blue}{\frac{\beta}{\left(\alpha + \beta\right) + 2}} - \frac{\alpha}{\left(\alpha + \beta\right) + 2}\right) + 1}{2} \]
      6. lift-+.f64N/A

        \[\leadsto \frac{\left(\frac{\beta}{\color{blue}{\left(\alpha + \beta\right) + 2}} - \frac{\alpha}{\left(\alpha + \beta\right) + 2}\right) + 1}{2} \]
      7. lift-+.f64N/A

        \[\leadsto \frac{\left(\frac{\beta}{\color{blue}{\left(\alpha + \beta\right)} + 2} - \frac{\alpha}{\left(\alpha + \beta\right) + 2}\right) + 1}{2} \]
      8. +-commutativeN/A

        \[\leadsto \frac{\left(\frac{\beta}{\color{blue}{\left(\beta + \alpha\right)} + 2} - \frac{\alpha}{\left(\alpha + \beta\right) + 2}\right) + 1}{2} \]
      9. associate-+l+N/A

        \[\leadsto \frac{\left(\frac{\beta}{\color{blue}{\beta + \left(\alpha + 2\right)}} - \frac{\alpha}{\left(\alpha + \beta\right) + 2}\right) + 1}{2} \]
      10. lower-+.f64N/A

        \[\leadsto \frac{\left(\frac{\beta}{\color{blue}{\beta + \left(\alpha + 2\right)}} - \frac{\alpha}{\left(\alpha + \beta\right) + 2}\right) + 1}{2} \]
      11. lower-+.f64N/A

        \[\leadsto \frac{\left(\frac{\beta}{\beta + \color{blue}{\left(\alpha + 2\right)}} - \frac{\alpha}{\left(\alpha + \beta\right) + 2}\right) + 1}{2} \]
      12. lower-/.f6499.9

        \[\leadsto \frac{\left(\frac{\beta}{\beta + \left(\alpha + 2\right)} - \color{blue}{\frac{\alpha}{\left(\alpha + \beta\right) + 2}}\right) + 1}{2} \]
      13. lift-+.f64N/A

        \[\leadsto \frac{\left(\frac{\beta}{\beta + \left(\alpha + 2\right)} - \frac{\alpha}{\color{blue}{\left(\alpha + \beta\right) + 2}}\right) + 1}{2} \]
      14. lift-+.f64N/A

        \[\leadsto \frac{\left(\frac{\beta}{\beta + \left(\alpha + 2\right)} - \frac{\alpha}{\color{blue}{\left(\alpha + \beta\right)} + 2}\right) + 1}{2} \]
      15. +-commutativeN/A

        \[\leadsto \frac{\left(\frac{\beta}{\beta + \left(\alpha + 2\right)} - \frac{\alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2}\right) + 1}{2} \]
      16. associate-+l+N/A

        \[\leadsto \frac{\left(\frac{\beta}{\beta + \left(\alpha + 2\right)} - \frac{\alpha}{\color{blue}{\beta + \left(\alpha + 2\right)}}\right) + 1}{2} \]
      17. lower-+.f64N/A

        \[\leadsto \frac{\left(\frac{\beta}{\beta + \left(\alpha + 2\right)} - \frac{\alpha}{\color{blue}{\beta + \left(\alpha + 2\right)}}\right) + 1}{2} \]
      18. lower-+.f6499.9

        \[\leadsto \frac{\left(\frac{\beta}{\beta + \left(\alpha + 2\right)} - \frac{\alpha}{\beta + \color{blue}{\left(\alpha + 2\right)}}\right) + 1}{2} \]
    4. Applied rewrites99.9%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.99996:\\ \;\;\;\;\frac{\beta + \mathsf{fma}\left(\mathsf{fma}\left(-0.5, \beta, -1\right), \frac{\beta + \left(\beta + 2\right)}{\alpha}, 1\right)}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\frac{1 + \left(\frac{\beta}{\beta + \left(\alpha + 2\right)} - \frac{\alpha}{\beta + \left(\alpha + 2\right)}\right)}{2}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 99.9% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.99996:\\ \;\;\;\;\frac{\beta + \mathsf{fma}\left(\mathsf{fma}\left(-0.5, \beta, -1\right), \frac{\beta + \left(\beta + 2\right)}{\alpha}, 1\right)}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{\mathsf{fma}\left(\beta, \frac{\alpha}{-\beta}, \beta\right)}{\beta + \left(\alpha + 2\right)}, 0.5, 0.5\right)\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= (/ (- beta alpha) (+ (+ beta alpha) 2.0)) -0.99996)
   (/
    (+ beta (fma (fma -0.5 beta -1.0) (/ (+ beta (+ beta 2.0)) alpha) 1.0))
    alpha)
   (fma
    (/ (fma beta (/ alpha (- beta)) beta) (+ beta (+ alpha 2.0)))
    0.5
    0.5)))
double code(double alpha, double beta) {
	double tmp;
	if (((beta - alpha) / ((beta + alpha) + 2.0)) <= -0.99996) {
		tmp = (beta + fma(fma(-0.5, beta, -1.0), ((beta + (beta + 2.0)) / alpha), 1.0)) / alpha;
	} else {
		tmp = fma((fma(beta, (alpha / -beta), beta) / (beta + (alpha + 2.0))), 0.5, 0.5);
	}
	return tmp;
}
function code(alpha, beta)
	tmp = 0.0
	if (Float64(Float64(beta - alpha) / Float64(Float64(beta + alpha) + 2.0)) <= -0.99996)
		tmp = Float64(Float64(beta + fma(fma(-0.5, beta, -1.0), Float64(Float64(beta + Float64(beta + 2.0)) / alpha), 1.0)) / alpha);
	else
		tmp = fma(Float64(fma(beta, Float64(alpha / Float64(-beta)), beta) / Float64(beta + Float64(alpha + 2.0))), 0.5, 0.5);
	end
	return tmp
end
code[alpha_, beta_] := If[LessEqual[N[(N[(beta - alpha), $MachinePrecision] / N[(N[(beta + alpha), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], -0.99996], N[(N[(beta + N[(N[(-0.5 * beta + -1.0), $MachinePrecision] * N[(N[(beta + N[(beta + 2.0), $MachinePrecision]), $MachinePrecision] / alpha), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision] / alpha), $MachinePrecision], N[(N[(N[(beta * N[(alpha / (-beta)), $MachinePrecision] + beta), $MachinePrecision] / N[(beta + N[(alpha + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 0.5 + 0.5), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.99996:\\
\;\;\;\;\frac{\beta + \mathsf{fma}\left(\mathsf{fma}\left(-0.5, \beta, -1\right), \frac{\beta + \left(\beta + 2\right)}{\alpha}, 1\right)}{\alpha}\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\frac{\mathsf{fma}\left(\beta, \frac{\alpha}{-\beta}, \beta\right)}{\beta + \left(\alpha + 2\right)}, 0.5, 0.5\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) < -0.99995999999999996

    1. Initial program 6.9%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\alpha + \beta\right)} + 2} + 1}{2} \]
      2. lift-+.f64N/A

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\alpha + \beta\right) + 2}} + 1}{2} \]
      3. flip--N/A

        \[\leadsto \frac{\frac{\color{blue}{\frac{\beta \cdot \beta - \alpha \cdot \alpha}{\beta + \alpha}}}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
      4. +-commutativeN/A

        \[\leadsto \frac{\frac{\frac{\beta \cdot \beta - \alpha \cdot \alpha}{\color{blue}{\alpha + \beta}}}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
      5. lift-+.f64N/A

        \[\leadsto \frac{\frac{\frac{\beta \cdot \beta - \alpha \cdot \alpha}{\color{blue}{\alpha + \beta}}}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
      6. associate-/l/N/A

        \[\leadsto \frac{\color{blue}{\frac{\beta \cdot \beta - \alpha \cdot \alpha}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)}} + 1}{2} \]
      7. lower-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\beta \cdot \beta - \alpha \cdot \alpha}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)}} + 1}{2} \]
      8. sqr-negN/A

        \[\leadsto \frac{\frac{\beta \cdot \beta - \color{blue}{\left(\mathsf{neg}\left(\alpha\right)\right) \cdot \left(\mathsf{neg}\left(\alpha\right)\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      9. difference-of-squaresN/A

        \[\leadsto \frac{\frac{\color{blue}{\left(\beta + \left(\mathsf{neg}\left(\alpha\right)\right)\right) \cdot \left(\beta - \left(\mathsf{neg}\left(\alpha\right)\right)\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      10. sub-negN/A

        \[\leadsto \frac{\frac{\color{blue}{\left(\beta - \alpha\right)} \cdot \left(\beta - \left(\mathsf{neg}\left(\alpha\right)\right)\right)}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      11. lift--.f64N/A

        \[\leadsto \frac{\frac{\color{blue}{\left(\beta - \alpha\right)} \cdot \left(\beta - \left(\mathsf{neg}\left(\alpha\right)\right)\right)}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      12. sub-negN/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \color{blue}{\left(\beta + \left(\mathsf{neg}\left(\left(\mathsf{neg}\left(\alpha\right)\right)\right)\right)\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      13. remove-double-negN/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \color{blue}{\alpha}\right)}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      14. +-commutativeN/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \color{blue}{\left(\alpha + \beta\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      15. lift-+.f64N/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \color{blue}{\left(\alpha + \beta\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      16. lower-*.f64N/A

        \[\leadsto \frac{\frac{\color{blue}{\left(\beta - \alpha\right) \cdot \left(\alpha + \beta\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      17. lift-+.f64N/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \color{blue}{\left(\alpha + \beta\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      18. +-commutativeN/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \color{blue}{\left(\beta + \alpha\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      19. lower-+.f64N/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \color{blue}{\left(\beta + \alpha\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      20. lower-*.f642.8

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}{\color{blue}{\left(\left(\alpha + \beta\right) + 2\right) \cdot \left(\alpha + \beta\right)}} + 1}{2} \]
      21. lift-+.f64N/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}{\color{blue}{\left(\left(\alpha + \beta\right) + 2\right)} \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      22. lift-+.f64N/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}{\left(\color{blue}{\left(\alpha + \beta\right)} + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      23. +-commutativeN/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}{\left(\color{blue}{\left(\beta + \alpha\right)} + 2\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      24. associate-+l+N/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}{\color{blue}{\left(\beta + \left(\alpha + 2\right)\right)} \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      25. lower-+.f64N/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}{\color{blue}{\left(\beta + \left(\alpha + 2\right)\right)} \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      26. lower-+.f642.8

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}{\left(\beta + \color{blue}{\left(\alpha + 2\right)}\right) \cdot \left(\alpha + \beta\right)} + 1}{2} \]
      27. lift-+.f64N/A

        \[\leadsto \frac{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}{\left(\beta + \left(\alpha + 2\right)\right) \cdot \color{blue}{\left(\alpha + \beta\right)}} + 1}{2} \]
    4. Applied rewrites2.8%

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

      \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(2 + 2 \cdot \beta\right) + \frac{1}{2} \cdot \frac{-1 \cdot {\left(2 + \beta\right)}^{2} - \beta \cdot \left(2 + \beta\right)}{\alpha}}{\alpha}} \]
    6. Applied rewrites99.8%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\mathsf{fma}\left(-0.5, \beta, -1\right), \frac{\beta + \left(2 + \beta\right)}{\alpha}, 1\right) + \beta}{\alpha}} \]

    if -0.99995999999999996 < (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64)))

    1. Initial program 99.8%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\alpha + \beta\right)} + 2} + 1}{2} \]
      2. lift-+.f64N/A

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\alpha + \beta\right) + 2}} + 1}{2} \]
      3. lift--.f64N/A

        \[\leadsto \frac{\frac{\color{blue}{\beta - \alpha}}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
      4. lift-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2}} + 1}{2} \]
      5. lift-+.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}}{2} \]
      6. clear-numN/A

        \[\leadsto \color{blue}{\frac{1}{\frac{2}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}}} \]
      7. associate-/r/N/A

        \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1\right)} \]
      8. lift-+.f64N/A

        \[\leadsto \frac{1}{2} \cdot \color{blue}{\left(\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1\right)} \]
      9. distribute-rgt-inN/A

        \[\leadsto \color{blue}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + 1 \cdot \frac{1}{2}} \]
      10. metadata-evalN/A

        \[\leadsto \frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + 1 \cdot \color{blue}{\frac{1}{2}} \]
      11. metadata-evalN/A

        \[\leadsto \frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + \color{blue}{\frac{1}{2}} \]
      12. metadata-evalN/A

        \[\leadsto \frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + \color{blue}{\frac{1}{2}} \]
      13. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2}, \frac{1}{2}, \frac{1}{2}\right)} \]
    4. Applied rewrites99.8%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)}, 0.5, 0.5\right)} \]
    5. Taylor expanded in beta around inf

      \[\leadsto \mathsf{fma}\left(\frac{\color{blue}{\beta \cdot \left(1 + -1 \cdot \frac{\alpha}{\beta}\right)}}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
    6. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \mathsf{fma}\left(\frac{\beta \cdot \color{blue}{\left(-1 \cdot \frac{\alpha}{\beta} + 1\right)}}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      2. distribute-lft-inN/A

        \[\leadsto \mathsf{fma}\left(\frac{\color{blue}{\beta \cdot \left(-1 \cdot \frac{\alpha}{\beta}\right) + \beta \cdot 1}}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      3. *-rgt-identityN/A

        \[\leadsto \mathsf{fma}\left(\frac{\beta \cdot \left(-1 \cdot \frac{\alpha}{\beta}\right) + \color{blue}{\beta}}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      4. lower-fma.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{\color{blue}{\mathsf{fma}\left(\beta, -1 \cdot \frac{\alpha}{\beta}, \beta\right)}}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      5. mul-1-negN/A

        \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\beta, \color{blue}{\mathsf{neg}\left(\frac{\alpha}{\beta}\right)}, \beta\right)}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      6. distribute-neg-frac2N/A

        \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\beta, \color{blue}{\frac{\alpha}{\mathsf{neg}\left(\beta\right)}}, \beta\right)}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      7. mul-1-negN/A

        \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\beta, \frac{\alpha}{\color{blue}{-1 \cdot \beta}}, \beta\right)}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      8. lower-/.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\beta, \color{blue}{\frac{\alpha}{-1 \cdot \beta}}, \beta\right)}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      9. mul-1-negN/A

        \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\beta, \frac{\alpha}{\color{blue}{\mathsf{neg}\left(\beta\right)}}, \beta\right)}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      10. lower-neg.f6499.8

        \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\beta, \frac{\alpha}{\color{blue}{-\beta}}, \beta\right)}{\beta + \left(\alpha + 2\right)}, 0.5, 0.5\right) \]
    7. Applied rewrites99.8%

      \[\leadsto \mathsf{fma}\left(\frac{\color{blue}{\mathsf{fma}\left(\beta, \frac{\alpha}{-\beta}, \beta\right)}}{\beta + \left(\alpha + 2\right)}, 0.5, 0.5\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.99996:\\ \;\;\;\;\frac{\beta + \mathsf{fma}\left(\mathsf{fma}\left(-0.5, \beta, -1\right), \frac{\beta + \left(\beta + 2\right)}{\alpha}, 1\right)}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{\mathsf{fma}\left(\beta, \frac{\alpha}{-\beta}, \beta\right)}{\beta + \left(\alpha + 2\right)}, 0.5, 0.5\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 99.6% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.999999:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{\mathsf{fma}\left(\beta, \frac{\alpha}{-\beta}, \beta\right)}{\beta + \left(\alpha + 2\right)}, 0.5, 0.5\right)\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= (/ (- beta alpha) (+ (+ beta alpha) 2.0)) -0.999999)
   (/ (+ beta 1.0) alpha)
   (fma
    (/ (fma beta (/ alpha (- beta)) beta) (+ beta (+ alpha 2.0)))
    0.5
    0.5)))
double code(double alpha, double beta) {
	double tmp;
	if (((beta - alpha) / ((beta + alpha) + 2.0)) <= -0.999999) {
		tmp = (beta + 1.0) / alpha;
	} else {
		tmp = fma((fma(beta, (alpha / -beta), beta) / (beta + (alpha + 2.0))), 0.5, 0.5);
	}
	return tmp;
}
function code(alpha, beta)
	tmp = 0.0
	if (Float64(Float64(beta - alpha) / Float64(Float64(beta + alpha) + 2.0)) <= -0.999999)
		tmp = Float64(Float64(beta + 1.0) / alpha);
	else
		tmp = fma(Float64(fma(beta, Float64(alpha / Float64(-beta)), beta) / Float64(beta + Float64(alpha + 2.0))), 0.5, 0.5);
	end
	return tmp
end
code[alpha_, beta_] := If[LessEqual[N[(N[(beta - alpha), $MachinePrecision] / N[(N[(beta + alpha), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], -0.999999], N[(N[(beta + 1.0), $MachinePrecision] / alpha), $MachinePrecision], N[(N[(N[(beta * N[(alpha / (-beta)), $MachinePrecision] + beta), $MachinePrecision] / N[(beta + N[(alpha + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 0.5 + 0.5), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.999999:\\
\;\;\;\;\frac{\beta + 1}{\alpha}\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\frac{\mathsf{fma}\left(\beta, \frac{\alpha}{-\beta}, \beta\right)}{\beta + \left(\alpha + 2\right)}, 0.5, 0.5\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) < -0.999998999999999971

    1. Initial program 5.9%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Add Preprocessing
    3. Taylor expanded in alpha around inf

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    4. Step-by-step derivation
      1. associate-*r/N/A

        \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(2 + 2 \cdot \beta\right)}{\alpha}} \]
      2. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(2 + 2 \cdot \beta\right)}{\alpha}} \]
      3. distribute-lft-inN/A

        \[\leadsto \frac{\color{blue}{\frac{1}{2} \cdot 2 + \frac{1}{2} \cdot \left(2 \cdot \beta\right)}}{\alpha} \]
      4. metadata-evalN/A

        \[\leadsto \frac{\color{blue}{1} + \frac{1}{2} \cdot \left(2 \cdot \beta\right)}{\alpha} \]
      5. associate-*r*N/A

        \[\leadsto \frac{1 + \color{blue}{\left(\frac{1}{2} \cdot 2\right) \cdot \beta}}{\alpha} \]
      6. metadata-evalN/A

        \[\leadsto \frac{1 + \color{blue}{1} \cdot \beta}{\alpha} \]
      7. *-lft-identityN/A

        \[\leadsto \frac{1 + \color{blue}{\beta}}{\alpha} \]
      8. lower-+.f6499.7

        \[\leadsto \frac{\color{blue}{1 + \beta}}{\alpha} \]
    5. Applied rewrites99.7%

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

    if -0.999998999999999971 < (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64)))

    1. Initial program 99.7%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\alpha + \beta\right)} + 2} + 1}{2} \]
      2. lift-+.f64N/A

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\alpha + \beta\right) + 2}} + 1}{2} \]
      3. lift--.f64N/A

        \[\leadsto \frac{\frac{\color{blue}{\beta - \alpha}}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
      4. lift-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2}} + 1}{2} \]
      5. lift-+.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}}{2} \]
      6. clear-numN/A

        \[\leadsto \color{blue}{\frac{1}{\frac{2}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}}} \]
      7. associate-/r/N/A

        \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1\right)} \]
      8. lift-+.f64N/A

        \[\leadsto \frac{1}{2} \cdot \color{blue}{\left(\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1\right)} \]
      9. distribute-rgt-inN/A

        \[\leadsto \color{blue}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + 1 \cdot \frac{1}{2}} \]
      10. metadata-evalN/A

        \[\leadsto \frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + 1 \cdot \color{blue}{\frac{1}{2}} \]
      11. metadata-evalN/A

        \[\leadsto \frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + \color{blue}{\frac{1}{2}} \]
      12. metadata-evalN/A

        \[\leadsto \frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + \color{blue}{\frac{1}{2}} \]
      13. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2}, \frac{1}{2}, \frac{1}{2}\right)} \]
    4. Applied rewrites99.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)}, 0.5, 0.5\right)} \]
    5. Taylor expanded in beta around inf

      \[\leadsto \mathsf{fma}\left(\frac{\color{blue}{\beta \cdot \left(1 + -1 \cdot \frac{\alpha}{\beta}\right)}}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
    6. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \mathsf{fma}\left(\frac{\beta \cdot \color{blue}{\left(-1 \cdot \frac{\alpha}{\beta} + 1\right)}}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      2. distribute-lft-inN/A

        \[\leadsto \mathsf{fma}\left(\frac{\color{blue}{\beta \cdot \left(-1 \cdot \frac{\alpha}{\beta}\right) + \beta \cdot 1}}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      3. *-rgt-identityN/A

        \[\leadsto \mathsf{fma}\left(\frac{\beta \cdot \left(-1 \cdot \frac{\alpha}{\beta}\right) + \color{blue}{\beta}}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      4. lower-fma.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{\color{blue}{\mathsf{fma}\left(\beta, -1 \cdot \frac{\alpha}{\beta}, \beta\right)}}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      5. mul-1-negN/A

        \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\beta, \color{blue}{\mathsf{neg}\left(\frac{\alpha}{\beta}\right)}, \beta\right)}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      6. distribute-neg-frac2N/A

        \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\beta, \color{blue}{\frac{\alpha}{\mathsf{neg}\left(\beta\right)}}, \beta\right)}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      7. mul-1-negN/A

        \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\beta, \frac{\alpha}{\color{blue}{-1 \cdot \beta}}, \beta\right)}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      8. lower-/.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\beta, \color{blue}{\frac{\alpha}{-1 \cdot \beta}}, \beta\right)}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      9. mul-1-negN/A

        \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\beta, \frac{\alpha}{\color{blue}{\mathsf{neg}\left(\beta\right)}}, \beta\right)}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      10. lower-neg.f6499.7

        \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\beta, \frac{\alpha}{\color{blue}{-\beta}}, \beta\right)}{\beta + \left(\alpha + 2\right)}, 0.5, 0.5\right) \]
    7. Applied rewrites99.7%

      \[\leadsto \mathsf{fma}\left(\frac{\color{blue}{\mathsf{fma}\left(\beta, \frac{\alpha}{-\beta}, \beta\right)}}{\beta + \left(\alpha + 2\right)}, 0.5, 0.5\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.999999:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{\mathsf{fma}\left(\beta, \frac{\alpha}{-\beta}, \beta\right)}{\beta + \left(\alpha + 2\right)}, 0.5, 0.5\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 99.6% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.999999:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{1}{\frac{\beta + \left(\alpha + 2\right)}{\beta - \alpha}}, 0.5, 0.5\right)\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= (/ (- beta alpha) (+ (+ beta alpha) 2.0)) -0.999999)
   (/ (+ beta 1.0) alpha)
   (fma (/ 1.0 (/ (+ beta (+ alpha 2.0)) (- beta alpha))) 0.5 0.5)))
double code(double alpha, double beta) {
	double tmp;
	if (((beta - alpha) / ((beta + alpha) + 2.0)) <= -0.999999) {
		tmp = (beta + 1.0) / alpha;
	} else {
		tmp = fma((1.0 / ((beta + (alpha + 2.0)) / (beta - alpha))), 0.5, 0.5);
	}
	return tmp;
}
function code(alpha, beta)
	tmp = 0.0
	if (Float64(Float64(beta - alpha) / Float64(Float64(beta + alpha) + 2.0)) <= -0.999999)
		tmp = Float64(Float64(beta + 1.0) / alpha);
	else
		tmp = fma(Float64(1.0 / Float64(Float64(beta + Float64(alpha + 2.0)) / Float64(beta - alpha))), 0.5, 0.5);
	end
	return tmp
end
code[alpha_, beta_] := If[LessEqual[N[(N[(beta - alpha), $MachinePrecision] / N[(N[(beta + alpha), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], -0.999999], N[(N[(beta + 1.0), $MachinePrecision] / alpha), $MachinePrecision], N[(N[(1.0 / N[(N[(beta + N[(alpha + 2.0), $MachinePrecision]), $MachinePrecision] / N[(beta - alpha), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 0.5 + 0.5), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.999999:\\
\;\;\;\;\frac{\beta + 1}{\alpha}\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\frac{1}{\frac{\beta + \left(\alpha + 2\right)}{\beta - \alpha}}, 0.5, 0.5\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) < -0.999998999999999971

    1. Initial program 5.9%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Add Preprocessing
    3. Taylor expanded in alpha around inf

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    4. Step-by-step derivation
      1. associate-*r/N/A

        \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(2 + 2 \cdot \beta\right)}{\alpha}} \]
      2. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(2 + 2 \cdot \beta\right)}{\alpha}} \]
      3. distribute-lft-inN/A

        \[\leadsto \frac{\color{blue}{\frac{1}{2} \cdot 2 + \frac{1}{2} \cdot \left(2 \cdot \beta\right)}}{\alpha} \]
      4. metadata-evalN/A

        \[\leadsto \frac{\color{blue}{1} + \frac{1}{2} \cdot \left(2 \cdot \beta\right)}{\alpha} \]
      5. associate-*r*N/A

        \[\leadsto \frac{1 + \color{blue}{\left(\frac{1}{2} \cdot 2\right) \cdot \beta}}{\alpha} \]
      6. metadata-evalN/A

        \[\leadsto \frac{1 + \color{blue}{1} \cdot \beta}{\alpha} \]
      7. *-lft-identityN/A

        \[\leadsto \frac{1 + \color{blue}{\beta}}{\alpha} \]
      8. lower-+.f6499.7

        \[\leadsto \frac{\color{blue}{1 + \beta}}{\alpha} \]
    5. Applied rewrites99.7%

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

    if -0.999998999999999971 < (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64)))

    1. Initial program 99.7%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\alpha + \beta\right)} + 2} + 1}{2} \]
      2. lift-+.f64N/A

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\alpha + \beta\right) + 2}} + 1}{2} \]
      3. lift--.f64N/A

        \[\leadsto \frac{\frac{\color{blue}{\beta - \alpha}}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
      4. lift-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2}} + 1}{2} \]
      5. lift-+.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}}{2} \]
      6. clear-numN/A

        \[\leadsto \color{blue}{\frac{1}{\frac{2}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}}} \]
      7. associate-/r/N/A

        \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1\right)} \]
      8. lift-+.f64N/A

        \[\leadsto \frac{1}{2} \cdot \color{blue}{\left(\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1\right)} \]
      9. distribute-rgt-inN/A

        \[\leadsto \color{blue}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + 1 \cdot \frac{1}{2}} \]
      10. metadata-evalN/A

        \[\leadsto \frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + 1 \cdot \color{blue}{\frac{1}{2}} \]
      11. metadata-evalN/A

        \[\leadsto \frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + \color{blue}{\frac{1}{2}} \]
      12. metadata-evalN/A

        \[\leadsto \frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + \color{blue}{\frac{1}{2}} \]
      13. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2}, \frac{1}{2}, \frac{1}{2}\right)} \]
    4. Applied rewrites99.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)}, 0.5, 0.5\right)} \]
    5. Step-by-step derivation
      1. lift--.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{\color{blue}{\beta - \alpha}}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      2. lift-+.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{\beta - \alpha}{\beta + \color{blue}{\left(\alpha + 2\right)}}, \frac{1}{2}, \frac{1}{2}\right) \]
      3. lift-+.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{\beta - \alpha}{\color{blue}{\beta + \left(\alpha + 2\right)}}, \frac{1}{2}, \frac{1}{2}\right) \]
      4. div-invN/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\beta - \alpha\right) \cdot \frac{1}{\beta + \left(\alpha + 2\right)}}, \frac{1}{2}, \frac{1}{2}\right) \]
      5. associate-*r/N/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{\left(\beta - \alpha\right) \cdot 1}{\beta + \left(\alpha + 2\right)}}, \frac{1}{2}, \frac{1}{2}\right) \]
      6. associate-*l/N/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)} \cdot 1}, \frac{1}{2}, \frac{1}{2}\right) \]
      7. *-inversesN/A

        \[\leadsto \mathsf{fma}\left(\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)} \cdot \color{blue}{\frac{\beta + \alpha}{\beta + \alpha}}, \frac{1}{2}, \frac{1}{2}\right) \]
      8. times-fracN/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}{\left(\beta + \left(\alpha + 2\right)\right) \cdot \left(\beta + \alpha\right)}}, \frac{1}{2}, \frac{1}{2}\right) \]
      9. lift-*.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{\color{blue}{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}}{\left(\beta + \left(\alpha + 2\right)\right) \cdot \left(\beta + \alpha\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      10. lift-*.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}{\color{blue}{\left(\beta + \left(\alpha + 2\right)\right) \cdot \left(\beta + \alpha\right)}}, \frac{1}{2}, \frac{1}{2}\right) \]
      11. clear-numN/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{1}{\frac{\left(\beta + \left(\alpha + 2\right)\right) \cdot \left(\beta + \alpha\right)}{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}}}, \frac{1}{2}, \frac{1}{2}\right) \]
      12. lower-/.f64N/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{1}{\frac{\left(\beta + \left(\alpha + 2\right)\right) \cdot \left(\beta + \alpha\right)}{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}}}, \frac{1}{2}, \frac{1}{2}\right) \]
      13. clear-numN/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{\color{blue}{\frac{1}{\frac{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}{\left(\beta + \left(\alpha + 2\right)\right) \cdot \left(\beta + \alpha\right)}}}}, \frac{1}{2}, \frac{1}{2}\right) \]
      14. lift-*.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{\frac{1}{\frac{\color{blue}{\left(\beta - \alpha\right) \cdot \left(\beta + \alpha\right)}}{\left(\beta + \left(\alpha + 2\right)\right) \cdot \left(\beta + \alpha\right)}}}, \frac{1}{2}, \frac{1}{2}\right) \]
      15. associate-/l*N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{\frac{1}{\color{blue}{\left(\beta - \alpha\right) \cdot \frac{\beta + \alpha}{\left(\beta + \left(\alpha + 2\right)\right) \cdot \left(\beta + \alpha\right)}}}}, \frac{1}{2}, \frac{1}{2}\right) \]
      16. lift-*.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{\frac{1}{\left(\beta - \alpha\right) \cdot \frac{\beta + \alpha}{\color{blue}{\left(\beta + \left(\alpha + 2\right)\right) \cdot \left(\beta + \alpha\right)}}}}, \frac{1}{2}, \frac{1}{2}\right) \]
      17. *-commutativeN/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{\frac{1}{\left(\beta - \alpha\right) \cdot \frac{\beta + \alpha}{\color{blue}{\left(\beta + \alpha\right) \cdot \left(\beta + \left(\alpha + 2\right)\right)}}}}, \frac{1}{2}, \frac{1}{2}\right) \]
      18. associate-/r*N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{\frac{1}{\left(\beta - \alpha\right) \cdot \color{blue}{\frac{\frac{\beta + \alpha}{\beta + \alpha}}{\beta + \left(\alpha + 2\right)}}}}, \frac{1}{2}, \frac{1}{2}\right) \]
    6. Applied rewrites99.7%

      \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{1}{\frac{\beta + \left(\alpha + 2\right)}{\beta - \alpha}}}, 0.5, 0.5\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.999999:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{1}{\frac{\beta + \left(\alpha + 2\right)}{\beta - \alpha}}, 0.5, 0.5\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 99.6% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.999999:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)}, 0.5, 0.5\right)\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= (/ (- beta alpha) (+ (+ beta alpha) 2.0)) -0.999999)
   (/ (+ beta 1.0) alpha)
   (fma (/ (- beta alpha) (+ beta (+ alpha 2.0))) 0.5 0.5)))
double code(double alpha, double beta) {
	double tmp;
	if (((beta - alpha) / ((beta + alpha) + 2.0)) <= -0.999999) {
		tmp = (beta + 1.0) / alpha;
	} else {
		tmp = fma(((beta - alpha) / (beta + (alpha + 2.0))), 0.5, 0.5);
	}
	return tmp;
}
function code(alpha, beta)
	tmp = 0.0
	if (Float64(Float64(beta - alpha) / Float64(Float64(beta + alpha) + 2.0)) <= -0.999999)
		tmp = Float64(Float64(beta + 1.0) / alpha);
	else
		tmp = fma(Float64(Float64(beta - alpha) / Float64(beta + Float64(alpha + 2.0))), 0.5, 0.5);
	end
	return tmp
end
code[alpha_, beta_] := If[LessEqual[N[(N[(beta - alpha), $MachinePrecision] / N[(N[(beta + alpha), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], -0.999999], N[(N[(beta + 1.0), $MachinePrecision] / alpha), $MachinePrecision], N[(N[(N[(beta - alpha), $MachinePrecision] / N[(beta + N[(alpha + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 0.5 + 0.5), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.999999:\\
\;\;\;\;\frac{\beta + 1}{\alpha}\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)}, 0.5, 0.5\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) < -0.999998999999999971

    1. Initial program 5.9%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Add Preprocessing
    3. Taylor expanded in alpha around inf

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    4. Step-by-step derivation
      1. associate-*r/N/A

        \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(2 + 2 \cdot \beta\right)}{\alpha}} \]
      2. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(2 + 2 \cdot \beta\right)}{\alpha}} \]
      3. distribute-lft-inN/A

        \[\leadsto \frac{\color{blue}{\frac{1}{2} \cdot 2 + \frac{1}{2} \cdot \left(2 \cdot \beta\right)}}{\alpha} \]
      4. metadata-evalN/A

        \[\leadsto \frac{\color{blue}{1} + \frac{1}{2} \cdot \left(2 \cdot \beta\right)}{\alpha} \]
      5. associate-*r*N/A

        \[\leadsto \frac{1 + \color{blue}{\left(\frac{1}{2} \cdot 2\right) \cdot \beta}}{\alpha} \]
      6. metadata-evalN/A

        \[\leadsto \frac{1 + \color{blue}{1} \cdot \beta}{\alpha} \]
      7. *-lft-identityN/A

        \[\leadsto \frac{1 + \color{blue}{\beta}}{\alpha} \]
      8. lower-+.f6499.7

        \[\leadsto \frac{\color{blue}{1 + \beta}}{\alpha} \]
    5. Applied rewrites99.7%

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

    if -0.999998999999999971 < (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64)))

    1. Initial program 99.7%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\alpha + \beta\right)} + 2} + 1}{2} \]
      2. lift-+.f64N/A

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\alpha + \beta\right) + 2}} + 1}{2} \]
      3. lift--.f64N/A

        \[\leadsto \frac{\frac{\color{blue}{\beta - \alpha}}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
      4. lift-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2}} + 1}{2} \]
      5. lift-+.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}}{2} \]
      6. clear-numN/A

        \[\leadsto \color{blue}{\frac{1}{\frac{2}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}}} \]
      7. associate-/r/N/A

        \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1\right)} \]
      8. lift-+.f64N/A

        \[\leadsto \frac{1}{2} \cdot \color{blue}{\left(\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1\right)} \]
      9. distribute-rgt-inN/A

        \[\leadsto \color{blue}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + 1 \cdot \frac{1}{2}} \]
      10. metadata-evalN/A

        \[\leadsto \frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + 1 \cdot \color{blue}{\frac{1}{2}} \]
      11. metadata-evalN/A

        \[\leadsto \frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + \color{blue}{\frac{1}{2}} \]
      12. metadata-evalN/A

        \[\leadsto \frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + \color{blue}{\frac{1}{2}} \]
      13. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2}, \frac{1}{2}, \frac{1}{2}\right)} \]
    4. Applied rewrites99.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)}, 0.5, 0.5\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.999999:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)}, 0.5, 0.5\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 99.6% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.999999:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\beta - \alpha, \frac{0.5}{\beta + \left(\alpha + 2\right)}, 0.5\right)\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= (/ (- beta alpha) (+ (+ beta alpha) 2.0)) -0.999999)
   (/ (+ beta 1.0) alpha)
   (fma (- beta alpha) (/ 0.5 (+ beta (+ alpha 2.0))) 0.5)))
double code(double alpha, double beta) {
	double tmp;
	if (((beta - alpha) / ((beta + alpha) + 2.0)) <= -0.999999) {
		tmp = (beta + 1.0) / alpha;
	} else {
		tmp = fma((beta - alpha), (0.5 / (beta + (alpha + 2.0))), 0.5);
	}
	return tmp;
}
function code(alpha, beta)
	tmp = 0.0
	if (Float64(Float64(beta - alpha) / Float64(Float64(beta + alpha) + 2.0)) <= -0.999999)
		tmp = Float64(Float64(beta + 1.0) / alpha);
	else
		tmp = fma(Float64(beta - alpha), Float64(0.5 / Float64(beta + Float64(alpha + 2.0))), 0.5);
	end
	return tmp
end
code[alpha_, beta_] := If[LessEqual[N[(N[(beta - alpha), $MachinePrecision] / N[(N[(beta + alpha), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], -0.999999], N[(N[(beta + 1.0), $MachinePrecision] / alpha), $MachinePrecision], N[(N[(beta - alpha), $MachinePrecision] * N[(0.5 / N[(beta + N[(alpha + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + 0.5), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.999999:\\
\;\;\;\;\frac{\beta + 1}{\alpha}\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\beta - \alpha, \frac{0.5}{\beta + \left(\alpha + 2\right)}, 0.5\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) < -0.999998999999999971

    1. Initial program 5.9%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Add Preprocessing
    3. Taylor expanded in alpha around inf

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    4. Step-by-step derivation
      1. associate-*r/N/A

        \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(2 + 2 \cdot \beta\right)}{\alpha}} \]
      2. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(2 + 2 \cdot \beta\right)}{\alpha}} \]
      3. distribute-lft-inN/A

        \[\leadsto \frac{\color{blue}{\frac{1}{2} \cdot 2 + \frac{1}{2} \cdot \left(2 \cdot \beta\right)}}{\alpha} \]
      4. metadata-evalN/A

        \[\leadsto \frac{\color{blue}{1} + \frac{1}{2} \cdot \left(2 \cdot \beta\right)}{\alpha} \]
      5. associate-*r*N/A

        \[\leadsto \frac{1 + \color{blue}{\left(\frac{1}{2} \cdot 2\right) \cdot \beta}}{\alpha} \]
      6. metadata-evalN/A

        \[\leadsto \frac{1 + \color{blue}{1} \cdot \beta}{\alpha} \]
      7. *-lft-identityN/A

        \[\leadsto \frac{1 + \color{blue}{\beta}}{\alpha} \]
      8. lower-+.f6499.7

        \[\leadsto \frac{\color{blue}{1 + \beta}}{\alpha} \]
    5. Applied rewrites99.7%

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

    if -0.999998999999999971 < (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64)))

    1. Initial program 99.7%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\alpha + \beta\right)} + 2} + 1}{2} \]
      2. lift-+.f64N/A

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\alpha + \beta\right) + 2}} + 1}{2} \]
      3. lift--.f64N/A

        \[\leadsto \frac{\frac{\color{blue}{\beta - \alpha}}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
      4. lift-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2}} + 1}{2} \]
      5. lift-+.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}}{2} \]
      6. clear-numN/A

        \[\leadsto \color{blue}{\frac{1}{\frac{2}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}}} \]
      7. associate-/r/N/A

        \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1\right)} \]
      8. lift-+.f64N/A

        \[\leadsto \frac{1}{2} \cdot \color{blue}{\left(\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1\right)} \]
      9. distribute-rgt-inN/A

        \[\leadsto \color{blue}{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + 1 \cdot \frac{1}{2}} \]
      10. metadata-evalN/A

        \[\leadsto \frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + 1 \cdot \color{blue}{\frac{1}{2}} \]
      11. metadata-evalN/A

        \[\leadsto \frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + \color{blue}{\frac{1}{2}} \]
      12. metadata-evalN/A

        \[\leadsto \frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} \cdot \frac{1}{2} + \color{blue}{\frac{1}{2}} \]
      13. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2}, \frac{1}{2}, \frac{1}{2}\right)} \]
    4. Applied rewrites99.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)}, 0.5, 0.5\right)} \]
    5. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \frac{\beta - \alpha}{\beta + \color{blue}{\left(\alpha + 2\right)}} \cdot \frac{1}{2} + \frac{1}{2} \]
      2. lift-+.f64N/A

        \[\leadsto \frac{\beta - \alpha}{\color{blue}{\beta + \left(\alpha + 2\right)}} \cdot \frac{1}{2} + \frac{1}{2} \]
      3. lift--.f64N/A

        \[\leadsto \frac{\color{blue}{\beta - \alpha}}{\beta + \left(\alpha + 2\right)} \cdot \frac{1}{2} + \frac{1}{2} \]
      4. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)}} \cdot \frac{1}{2} + \frac{1}{2} \]
      5. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)}} \cdot \frac{1}{2} + \frac{1}{2} \]
      6. associate-*l/N/A

        \[\leadsto \color{blue}{\frac{\left(\beta - \alpha\right) \cdot \frac{1}{2}}{\beta + \left(\alpha + 2\right)}} + \frac{1}{2} \]
      7. associate-/l*N/A

        \[\leadsto \color{blue}{\left(\beta - \alpha\right) \cdot \frac{\frac{1}{2}}{\beta + \left(\alpha + 2\right)}} + \frac{1}{2} \]
      8. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(\beta - \alpha, \frac{\frac{1}{2}}{\beta + \left(\alpha + 2\right)}, \frac{1}{2}\right)} \]
      9. lower-/.f6499.6

        \[\leadsto \mathsf{fma}\left(\beta - \alpha, \color{blue}{\frac{0.5}{\beta + \left(\alpha + 2\right)}}, 0.5\right) \]
    6. Applied rewrites99.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\beta - \alpha, \frac{0.5}{\beta + \left(\alpha + 2\right)}, 0.5\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.999999:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\beta - \alpha, \frac{0.5}{\beta + \left(\alpha + 2\right)}, 0.5\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 98.1% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.5:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(0.5, \frac{\beta}{\beta + 2}, 0.5\right)\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= (/ (- beta alpha) (+ (+ beta alpha) 2.0)) -0.5)
   (/ (+ beta 1.0) alpha)
   (fma 0.5 (/ beta (+ beta 2.0)) 0.5)))
double code(double alpha, double beta) {
	double tmp;
	if (((beta - alpha) / ((beta + alpha) + 2.0)) <= -0.5) {
		tmp = (beta + 1.0) / alpha;
	} else {
		tmp = fma(0.5, (beta / (beta + 2.0)), 0.5);
	}
	return tmp;
}
function code(alpha, beta)
	tmp = 0.0
	if (Float64(Float64(beta - alpha) / Float64(Float64(beta + alpha) + 2.0)) <= -0.5)
		tmp = Float64(Float64(beta + 1.0) / alpha);
	else
		tmp = fma(0.5, Float64(beta / Float64(beta + 2.0)), 0.5);
	end
	return tmp
end
code[alpha_, beta_] := If[LessEqual[N[(N[(beta - alpha), $MachinePrecision] / N[(N[(beta + alpha), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], -0.5], N[(N[(beta + 1.0), $MachinePrecision] / alpha), $MachinePrecision], N[(0.5 * N[(beta / N[(beta + 2.0), $MachinePrecision]), $MachinePrecision] + 0.5), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.5:\\
\;\;\;\;\frac{\beta + 1}{\alpha}\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(0.5, \frac{\beta}{\beta + 2}, 0.5\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) < -0.5

    1. Initial program 10.2%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Add Preprocessing
    3. Taylor expanded in alpha around inf

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    4. Step-by-step derivation
      1. associate-*r/N/A

        \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(2 + 2 \cdot \beta\right)}{\alpha}} \]
      2. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(2 + 2 \cdot \beta\right)}{\alpha}} \]
      3. distribute-lft-inN/A

        \[\leadsto \frac{\color{blue}{\frac{1}{2} \cdot 2 + \frac{1}{2} \cdot \left(2 \cdot \beta\right)}}{\alpha} \]
      4. metadata-evalN/A

        \[\leadsto \frac{\color{blue}{1} + \frac{1}{2} \cdot \left(2 \cdot \beta\right)}{\alpha} \]
      5. associate-*r*N/A

        \[\leadsto \frac{1 + \color{blue}{\left(\frac{1}{2} \cdot 2\right) \cdot \beta}}{\alpha} \]
      6. metadata-evalN/A

        \[\leadsto \frac{1 + \color{blue}{1} \cdot \beta}{\alpha} \]
      7. *-lft-identityN/A

        \[\leadsto \frac{1 + \color{blue}{\beta}}{\alpha} \]
      8. lower-+.f6496.3

        \[\leadsto \frac{\color{blue}{1 + \beta}}{\alpha} \]
    5. Applied rewrites96.3%

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

    if -0.5 < (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64)))

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Add Preprocessing
    3. Taylor expanded in alpha around 0

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(1 + \frac{\beta}{2 + \beta}\right)} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \frac{1}{2} \cdot \color{blue}{\left(\frac{\beta}{2 + \beta} + 1\right)} \]
      2. distribute-lft-inN/A

        \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{\beta}{2 + \beta} + \frac{1}{2} \cdot 1} \]
      3. metadata-evalN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\beta}{2 + \beta} + \color{blue}{\frac{1}{2}} \]
      4. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{1}{2}, \frac{\beta}{2 + \beta}, \frac{1}{2}\right)} \]
      5. lower-/.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, \color{blue}{\frac{\beta}{2 + \beta}}, \frac{1}{2}\right) \]
      6. lower-+.f6499.0

        \[\leadsto \mathsf{fma}\left(0.5, \frac{\beta}{\color{blue}{2 + \beta}}, 0.5\right) \]
    5. Applied rewrites99.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.5, \frac{\beta}{2 + \beta}, 0.5\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.5:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(0.5, \frac{\beta}{\beta + 2}, 0.5\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 8: 62.7% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.5:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= (/ (- beta alpha) (+ (+ beta alpha) 2.0)) -0.5)
   (/ (+ beta 1.0) alpha)
   1.0))
double code(double alpha, double beta) {
	double tmp;
	if (((beta - alpha) / ((beta + alpha) + 2.0)) <= -0.5) {
		tmp = (beta + 1.0) / alpha;
	} 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 - alpha) / ((beta + alpha) + 2.0d0)) <= (-0.5d0)) then
        tmp = (beta + 1.0d0) / alpha
    else
        tmp = 1.0d0
    end if
    code = tmp
end function
public static double code(double alpha, double beta) {
	double tmp;
	if (((beta - alpha) / ((beta + alpha) + 2.0)) <= -0.5) {
		tmp = (beta + 1.0) / alpha;
	} else {
		tmp = 1.0;
	}
	return tmp;
}
def code(alpha, beta):
	tmp = 0
	if ((beta - alpha) / ((beta + alpha) + 2.0)) <= -0.5:
		tmp = (beta + 1.0) / alpha
	else:
		tmp = 1.0
	return tmp
function code(alpha, beta)
	tmp = 0.0
	if (Float64(Float64(beta - alpha) / Float64(Float64(beta + alpha) + 2.0)) <= -0.5)
		tmp = Float64(Float64(beta + 1.0) / alpha);
	else
		tmp = 1.0;
	end
	return tmp
end
function tmp_2 = code(alpha, beta)
	tmp = 0.0;
	if (((beta - alpha) / ((beta + alpha) + 2.0)) <= -0.5)
		tmp = (beta + 1.0) / alpha;
	else
		tmp = 1.0;
	end
	tmp_2 = tmp;
end
code[alpha_, beta_] := If[LessEqual[N[(N[(beta - alpha), $MachinePrecision] / N[(N[(beta + alpha), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], -0.5], N[(N[(beta + 1.0), $MachinePrecision] / alpha), $MachinePrecision], 1.0]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.5:\\
\;\;\;\;\frac{\beta + 1}{\alpha}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) < -0.5

    1. Initial program 10.2%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Add Preprocessing
    3. Taylor expanded in alpha around inf

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    4. Step-by-step derivation
      1. associate-*r/N/A

        \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(2 + 2 \cdot \beta\right)}{\alpha}} \]
      2. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(2 + 2 \cdot \beta\right)}{\alpha}} \]
      3. distribute-lft-inN/A

        \[\leadsto \frac{\color{blue}{\frac{1}{2} \cdot 2 + \frac{1}{2} \cdot \left(2 \cdot \beta\right)}}{\alpha} \]
      4. metadata-evalN/A

        \[\leadsto \frac{\color{blue}{1} + \frac{1}{2} \cdot \left(2 \cdot \beta\right)}{\alpha} \]
      5. associate-*r*N/A

        \[\leadsto \frac{1 + \color{blue}{\left(\frac{1}{2} \cdot 2\right) \cdot \beta}}{\alpha} \]
      6. metadata-evalN/A

        \[\leadsto \frac{1 + \color{blue}{1} \cdot \beta}{\alpha} \]
      7. *-lft-identityN/A

        \[\leadsto \frac{1 + \color{blue}{\beta}}{\alpha} \]
      8. lower-+.f6496.3

        \[\leadsto \frac{\color{blue}{1 + \beta}}{\alpha} \]
    5. Applied rewrites96.3%

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

    if -0.5 < (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64)))

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Add Preprocessing
    3. Taylor expanded in beta around inf

      \[\leadsto \color{blue}{1} \]
    4. Step-by-step derivation
      1. Applied rewrites48.1%

        \[\leadsto \color{blue}{1} \]
    5. Recombined 2 regimes into one program.
    6. Final simplification62.0%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.5:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]
    7. Add Preprocessing

    Alternative 9: 36.6% accurate, 35.0× speedup?

    \[\begin{array}{l} \\ 1 \end{array} \]
    (FPCore (alpha beta) :precision binary64 1.0)
    double code(double alpha, double beta) {
    	return 1.0;
    }
    
    real(8) function code(alpha, beta)
        real(8), intent (in) :: alpha
        real(8), intent (in) :: beta
        code = 1.0d0
    end function
    
    public static double code(double alpha, double beta) {
    	return 1.0;
    }
    
    def code(alpha, beta):
    	return 1.0
    
    function code(alpha, beta)
    	return 1.0
    end
    
    function tmp = code(alpha, beta)
    	tmp = 1.0;
    end
    
    code[alpha_, beta_] := 1.0
    
    \begin{array}{l}
    
    \\
    1
    \end{array}
    
    Derivation
    1. Initial program 74.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Add Preprocessing
    3. Taylor expanded in beta around inf

      \[\leadsto \color{blue}{1} \]
    4. Step-by-step derivation
      1. Applied rewrites35.8%

        \[\leadsto \color{blue}{1} \]
      2. Add Preprocessing

      Reproduce

      ?
      herbie shell --seed 2024212 
      (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))