Octave 3.8, jcobi/1

Percentage Accurate: 74.9% → 99.7%
Time: 3.3s
Alternatives: 8
Speedup: 0.5×

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;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(alpha, beta)
use fmin_fmax_functions
    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}

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 8 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: 74.9% 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;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(alpha, beta)
use fmin_fmax_functions
    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, 0.4× speedup?

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

\\
\begin{array}{l}
t_0 := \left(-2 - \beta\right) - \alpha\\
\mathbf{if}\;\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \leq 0:\\
\;\;\;\;\frac{\mathsf{fma}\left(\frac{-1}{t\_0}, \beta, \frac{2 + \beta}{\alpha}\right)}{2}\\

\mathbf{else}:\\
\;\;\;\;0.5 \cdot \frac{t\_0 - \left(\beta - \alpha\right)}{t\_0}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64)) < 0.0

    1. Initial program 74.9%

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \color{blue}{\left(\frac{\alpha}{\left(\alpha + \beta\right) + 2} - 1\right)}}{2} \]
      13. lower-/.f6475.7

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\color{blue}{\left(\alpha + \beta\right) - \left(\mathsf{neg}\left(2\right)\right)}} - 1\right)}{2} \]
      17. metadata-eval75.7

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\left(\alpha + \beta\right) - \color{blue}{-2}} - 1\right)}{2} \]
    3. Applied rewrites75.7%

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \color{blue}{\left(\mathsf{neg}\left(\left(1 - \frac{\alpha}{\left(\alpha + \beta\right) - -2}\right)\right)\right)}}{2} \]
      4. add-flip-revN/A

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

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

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

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

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

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

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{1}{\left(\alpha + \beta\right) - -2}, \beta, \mathsf{neg}\left(\left(\frac{\alpha}{\left(\alpha + \beta\right) - -2} - 1\right)\right)\right)}}{2} \]
    5. Applied rewrites75.7%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{-1}{\left(-2 - \beta\right) - \alpha}, \beta, 1 - \frac{\alpha}{\beta - \left(-2 - \alpha\right)}\right)}}{2} \]
    6. Taylor expanded in alpha around inf

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

        \[\leadsto \frac{\mathsf{fma}\left(\frac{-1}{\left(-2 - \beta\right) - \alpha}, \beta, \frac{2 + \beta}{\color{blue}{\alpha}}\right)}{2} \]
      2. lower-+.f6429.1

        \[\leadsto \frac{\mathsf{fma}\left(\frac{-1}{\left(-2 - \beta\right) - \alpha}, \beta, \frac{2 + \beta}{\alpha}\right)}{2} \]
    8. Applied rewrites29.1%

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

    if 0.0 < (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64))

    1. Initial program 74.9%

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \color{blue}{\left(\frac{\alpha}{\left(\alpha + \beta\right) + 2} - 1\right)}}{2} \]
      13. lower-/.f6475.7

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\color{blue}{\left(\alpha + \beta\right) - \left(\mathsf{neg}\left(2\right)\right)}} - 1\right)}{2} \]
      17. metadata-eval75.7

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\left(\alpha + \beta\right) - \color{blue}{-2}} - 1\right)}{2} \]
    3. Applied rewrites75.7%

      \[\leadsto \frac{\color{blue}{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\left(\alpha + \beta\right) - -2} - 1\right)}}{2} \]
    4. Applied rewrites74.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{2} \cdot \frac{\left(\left(-2 - \beta\right) - \alpha\right) - \color{blue}{\left(\beta - \alpha\right)}}{\left(-2 - \beta\right) - \alpha} \]
      17. lower--.f6475.3

        \[\leadsto 0.5 \cdot \frac{\color{blue}{\left(\left(-2 - \beta\right) - \alpha\right) - \left(\beta - \alpha\right)}}{\left(-2 - \beta\right) - \alpha} \]
    6. Applied rewrites75.3%

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

Alternative 2: 99.7% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(-2 - \beta\right) - \alpha\\ \mathbf{if}\;\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \leq 0:\\ \;\;\;\;0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \frac{t\_0 - \left(\beta - \alpha\right)}{t\_0}\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (let* ((t_0 (- (- -2.0 beta) alpha)))
   (if (<= (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0) 0.0)
     (* 0.5 (/ (+ 2.0 (* 2.0 beta)) alpha))
     (* 0.5 (/ (- t_0 (- beta alpha)) t_0)))))
double code(double alpha, double beta) {
	double t_0 = (-2.0 - beta) - alpha;
	double tmp;
	if (((((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0) <= 0.0) {
		tmp = 0.5 * ((2.0 + (2.0 * beta)) / alpha);
	} else {
		tmp = 0.5 * ((t_0 - (beta - alpha)) / t_0);
	}
	return tmp;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(alpha, beta)
use fmin_fmax_functions
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8) :: t_0
    real(8) :: tmp
    t_0 = ((-2.0d0) - beta) - alpha
    if (((((beta - alpha) / ((alpha + beta) + 2.0d0)) + 1.0d0) / 2.0d0) <= 0.0d0) then
        tmp = 0.5d0 * ((2.0d0 + (2.0d0 * beta)) / alpha)
    else
        tmp = 0.5d0 * ((t_0 - (beta - alpha)) / t_0)
    end if
    code = tmp
end function
public static double code(double alpha, double beta) {
	double t_0 = (-2.0 - beta) - alpha;
	double tmp;
	if (((((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0) <= 0.0) {
		tmp = 0.5 * ((2.0 + (2.0 * beta)) / alpha);
	} else {
		tmp = 0.5 * ((t_0 - (beta - alpha)) / t_0);
	}
	return tmp;
}
def code(alpha, beta):
	t_0 = (-2.0 - beta) - alpha
	tmp = 0
	if ((((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0) <= 0.0:
		tmp = 0.5 * ((2.0 + (2.0 * beta)) / alpha)
	else:
		tmp = 0.5 * ((t_0 - (beta - alpha)) / t_0)
	return tmp
function code(alpha, beta)
	t_0 = Float64(Float64(-2.0 - beta) - alpha)
	tmp = 0.0
	if (Float64(Float64(Float64(Float64(beta - alpha) / Float64(Float64(alpha + beta) + 2.0)) + 1.0) / 2.0) <= 0.0)
		tmp = Float64(0.5 * Float64(Float64(2.0 + Float64(2.0 * beta)) / alpha));
	else
		tmp = Float64(0.5 * Float64(Float64(t_0 - Float64(beta - alpha)) / t_0));
	end
	return tmp
end
function tmp_2 = code(alpha, beta)
	t_0 = (-2.0 - beta) - alpha;
	tmp = 0.0;
	if (((((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0) <= 0.0)
		tmp = 0.5 * ((2.0 + (2.0 * beta)) / alpha);
	else
		tmp = 0.5 * ((t_0 - (beta - alpha)) / t_0);
	end
	tmp_2 = tmp;
end
code[alpha_, beta_] := Block[{t$95$0 = N[(N[(-2.0 - beta), $MachinePrecision] - alpha), $MachinePrecision]}, If[LessEqual[N[(N[(N[(N[(beta - alpha), $MachinePrecision] / N[(N[(alpha + beta), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / 2.0), $MachinePrecision], 0.0], N[(0.5 * N[(N[(2.0 + N[(2.0 * beta), $MachinePrecision]), $MachinePrecision] / alpha), $MachinePrecision]), $MachinePrecision], N[(0.5 * N[(N[(t$95$0 - N[(beta - alpha), $MachinePrecision]), $MachinePrecision] / t$95$0), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(-2 - \beta\right) - \alpha\\
\mathbf{if}\;\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \leq 0:\\
\;\;\;\;0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha}\\

\mathbf{else}:\\
\;\;\;\;0.5 \cdot \frac{t\_0 - \left(\beta - \alpha\right)}{t\_0}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64)) < 0.0

    1. Initial program 74.9%

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \color{blue}{\left(\frac{\alpha}{\left(\alpha + \beta\right) + 2} - 1\right)}}{2} \]
      13. lower-/.f6475.7

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\color{blue}{\left(\alpha + \beta\right) - \left(\mathsf{neg}\left(2\right)\right)}} - 1\right)}{2} \]
      17. metadata-eval75.7

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\left(\alpha + \beta\right) - \color{blue}{-2}} - 1\right)}{2} \]
    3. Applied rewrites75.7%

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \color{blue}{\left(\mathsf{neg}\left(\left(1 - \frac{\alpha}{\left(\alpha + \beta\right) - -2}\right)\right)\right)}}{2} \]
      4. add-flip-revN/A

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

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

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

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

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

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

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{1}{\left(\alpha + \beta\right) - -2}, \beta, \mathsf{neg}\left(\left(\frac{\alpha}{\left(\alpha + \beta\right) - -2} - 1\right)\right)\right)}}{2} \]
    5. Applied rewrites75.7%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{-1}{\left(-2 - \beta\right) - \alpha}, \beta, 1 - \frac{\alpha}{\beta - \left(-2 - \alpha\right)}\right)}}{2} \]
    6. Taylor expanded in alpha around inf

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    7. Step-by-step derivation
      1. lower-*.f64N/A

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

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

        \[\leadsto \frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha} \]
      4. lower-*.f6429.1

        \[\leadsto 0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha} \]
    8. Applied rewrites29.1%

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

    if 0.0 < (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64))

    1. Initial program 74.9%

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \color{blue}{\left(\frac{\alpha}{\left(\alpha + \beta\right) + 2} - 1\right)}}{2} \]
      13. lower-/.f6475.7

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\color{blue}{\left(\alpha + \beta\right) - \left(\mathsf{neg}\left(2\right)\right)}} - 1\right)}{2} \]
      17. metadata-eval75.7

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\left(\alpha + \beta\right) - \color{blue}{-2}} - 1\right)}{2} \]
    3. Applied rewrites75.7%

      \[\leadsto \frac{\color{blue}{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\left(\alpha + \beta\right) - -2} - 1\right)}}{2} \]
    4. Applied rewrites74.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{2} \cdot \frac{\left(\left(-2 - \beta\right) - \alpha\right) - \color{blue}{\left(\beta - \alpha\right)}}{\left(-2 - \beta\right) - \alpha} \]
      17. lower--.f6475.3

        \[\leadsto 0.5 \cdot \frac{\color{blue}{\left(\left(-2 - \beta\right) - \alpha\right) - \left(\beta - \alpha\right)}}{\left(-2 - \beta\right) - \alpha} \]
    6. Applied rewrites75.3%

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

Alternative 3: 99.3% accurate, 0.5× speedup?

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

\\
\begin{array}{l}
\mathbf{if}\;\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \leq 0:\\
\;\;\;\;0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64)) < 0.0

    1. Initial program 74.9%

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \color{blue}{\left(\frac{\alpha}{\left(\alpha + \beta\right) + 2} - 1\right)}}{2} \]
      13. lower-/.f6475.7

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\color{blue}{\left(\alpha + \beta\right) - \left(\mathsf{neg}\left(2\right)\right)}} - 1\right)}{2} \]
      17. metadata-eval75.7

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\left(\alpha + \beta\right) - \color{blue}{-2}} - 1\right)}{2} \]
    3. Applied rewrites75.7%

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \color{blue}{\left(\mathsf{neg}\left(\left(1 - \frac{\alpha}{\left(\alpha + \beta\right) - -2}\right)\right)\right)}}{2} \]
      4. add-flip-revN/A

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

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

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

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

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

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

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{1}{\left(\alpha + \beta\right) - -2}, \beta, \mathsf{neg}\left(\left(\frac{\alpha}{\left(\alpha + \beta\right) - -2} - 1\right)\right)\right)}}{2} \]
    5. Applied rewrites75.7%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{-1}{\left(-2 - \beta\right) - \alpha}, \beta, 1 - \frac{\alpha}{\beta - \left(-2 - \alpha\right)}\right)}}{2} \]
    6. Taylor expanded in alpha around inf

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    7. Step-by-step derivation
      1. lower-*.f64N/A

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

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

        \[\leadsto \frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha} \]
      4. lower-*.f6429.1

        \[\leadsto 0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha} \]
    8. Applied rewrites29.1%

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

    if 0.0 < (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64))

    1. Initial program 74.9%

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\frac{\mathsf{neg}\left(\color{blue}{\left(\beta - \alpha\right)}\right)}{\mathsf{neg}\left(\left(\left(\alpha + \beta\right) + 2\right)\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      9. sub-negate-revN/A

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\frac{\alpha - \beta}{-2 - \left(\alpha + \beta\right)}, \color{blue}{\frac{1}{2}}, \frac{1}{2}\right) \]
      18. metadata-eval74.9

        \[\leadsto \mathsf{fma}\left(\frac{\alpha - \beta}{-2 - \left(\alpha + \beta\right)}, 0.5, \color{blue}{0.5}\right) \]
    3. Applied rewrites74.9%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\alpha - \beta}{-2 - \left(\alpha + \beta\right)}, 0.5, 0.5\right)} \]
    4. Applied rewrites74.9%

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

Alternative 4: 99.3% accurate, 0.5× speedup?

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

\\
\begin{array}{l}
\mathbf{if}\;\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \leq 0:\\
\;\;\;\;0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64)) < 0.0

    1. Initial program 74.9%

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \color{blue}{\left(\frac{\alpha}{\left(\alpha + \beta\right) + 2} - 1\right)}}{2} \]
      13. lower-/.f6475.7

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\color{blue}{\left(\alpha + \beta\right) - \left(\mathsf{neg}\left(2\right)\right)}} - 1\right)}{2} \]
      17. metadata-eval75.7

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\left(\alpha + \beta\right) - \color{blue}{-2}} - 1\right)}{2} \]
    3. Applied rewrites75.7%

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \color{blue}{\left(\mathsf{neg}\left(\left(1 - \frac{\alpha}{\left(\alpha + \beta\right) - -2}\right)\right)\right)}}{2} \]
      4. add-flip-revN/A

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

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

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

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

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

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

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{1}{\left(\alpha + \beta\right) - -2}, \beta, \mathsf{neg}\left(\left(\frac{\alpha}{\left(\alpha + \beta\right) - -2} - 1\right)\right)\right)}}{2} \]
    5. Applied rewrites75.7%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{-1}{\left(-2 - \beta\right) - \alpha}, \beta, 1 - \frac{\alpha}{\beta - \left(-2 - \alpha\right)}\right)}}{2} \]
    6. Taylor expanded in alpha around inf

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    7. Step-by-step derivation
      1. lower-*.f64N/A

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

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

        \[\leadsto \frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha} \]
      4. lower-*.f6429.1

        \[\leadsto 0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha} \]
    8. Applied rewrites29.1%

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

    if 0.0 < (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64))

    1. Initial program 74.9%

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \color{blue}{\left(\frac{\alpha}{\left(\alpha + \beta\right) + 2} - 1\right)}}{2} \]
      13. lower-/.f6475.7

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\color{blue}{\left(\alpha + \beta\right) - \left(\mathsf{neg}\left(2\right)\right)}} - 1\right)}{2} \]
      17. metadata-eval75.7

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\left(\alpha + \beta\right) - \color{blue}{-2}} - 1\right)}{2} \]
    3. Applied rewrites75.7%

      \[\leadsto \frac{\color{blue}{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\left(\alpha + \beta\right) - -2} - 1\right)}}{2} \]
    4. Applied rewrites74.6%

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

Alternative 5: 98.4% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \leq 0.0002:\\ \;\;\;\;0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{\beta - \alpha}{\beta - -2}, 0.5, 0.5\right)\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0) 0.0002)
   (* 0.5 (/ (+ 2.0 (* 2.0 beta)) alpha))
   (fma (/ (- beta alpha) (- beta -2.0)) 0.5 0.5)))
double code(double alpha, double beta) {
	double tmp;
	if (((((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0) <= 0.0002) {
		tmp = 0.5 * ((2.0 + (2.0 * beta)) / alpha);
	} else {
		tmp = fma(((beta - alpha) / (beta - -2.0)), 0.5, 0.5);
	}
	return tmp;
}
function code(alpha, beta)
	tmp = 0.0
	if (Float64(Float64(Float64(Float64(beta - alpha) / Float64(Float64(alpha + beta) + 2.0)) + 1.0) / 2.0) <= 0.0002)
		tmp = Float64(0.5 * Float64(Float64(2.0 + Float64(2.0 * beta)) / alpha));
	else
		tmp = fma(Float64(Float64(beta - alpha) / Float64(beta - -2.0)), 0.5, 0.5);
	end
	return tmp
end
code[alpha_, beta_] := If[LessEqual[N[(N[(N[(N[(beta - alpha), $MachinePrecision] / N[(N[(alpha + beta), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / 2.0), $MachinePrecision], 0.0002], N[(0.5 * N[(N[(2.0 + N[(2.0 * beta), $MachinePrecision]), $MachinePrecision] / alpha), $MachinePrecision]), $MachinePrecision], N[(N[(N[(beta - alpha), $MachinePrecision] / N[(beta - -2.0), $MachinePrecision]), $MachinePrecision] * 0.5 + 0.5), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \leq 0.0002:\\
\;\;\;\;0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64)) < 2.0000000000000001e-4

    1. Initial program 74.9%

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \color{blue}{\left(\frac{\alpha}{\left(\alpha + \beta\right) + 2} - 1\right)}}{2} \]
      13. lower-/.f6475.7

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\color{blue}{\left(\alpha + \beta\right) - \left(\mathsf{neg}\left(2\right)\right)}} - 1\right)}{2} \]
      17. metadata-eval75.7

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\left(\alpha + \beta\right) - \color{blue}{-2}} - 1\right)}{2} \]
    3. Applied rewrites75.7%

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \color{blue}{\left(\mathsf{neg}\left(\left(1 - \frac{\alpha}{\left(\alpha + \beta\right) - -2}\right)\right)\right)}}{2} \]
      4. add-flip-revN/A

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

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

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

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

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

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

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{1}{\left(\alpha + \beta\right) - -2}, \beta, \mathsf{neg}\left(\left(\frac{\alpha}{\left(\alpha + \beta\right) - -2} - 1\right)\right)\right)}}{2} \]
    5. Applied rewrites75.7%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{-1}{\left(-2 - \beta\right) - \alpha}, \beta, 1 - \frac{\alpha}{\beta - \left(-2 - \alpha\right)}\right)}}{2} \]
    6. Taylor expanded in alpha around inf

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    7. Step-by-step derivation
      1. lower-*.f64N/A

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

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

        \[\leadsto \frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha} \]
      4. lower-*.f6429.1

        \[\leadsto 0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha} \]
    8. Applied rewrites29.1%

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

    if 2.0000000000000001e-4 < (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64))

    1. Initial program 74.9%

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\frac{\mathsf{neg}\left(\color{blue}{\left(\beta - \alpha\right)}\right)}{\mathsf{neg}\left(\left(\left(\alpha + \beta\right) + 2\right)\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      9. sub-negate-revN/A

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\frac{\alpha - \beta}{-2 - \left(\alpha + \beta\right)}, \color{blue}{\frac{1}{2}}, \frac{1}{2}\right) \]
      18. metadata-eval74.9

        \[\leadsto \mathsf{fma}\left(\frac{\alpha - \beta}{-2 - \left(\alpha + \beta\right)}, 0.5, \color{blue}{0.5}\right) \]
    3. Applied rewrites74.9%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\alpha - \beta}{-2 - \left(\alpha + \beta\right)}, 0.5, 0.5\right)} \]
    4. Applied rewrites74.9%

      \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{\beta - \alpha}{\beta - \left(-2 - \alpha\right)}}, 0.5, 0.5\right) \]
    5. Taylor expanded in alpha around 0

      \[\leadsto \mathsf{fma}\left(\frac{\beta - \alpha}{\beta - \color{blue}{-2}}, \frac{1}{2}, \frac{1}{2}\right) \]
    6. Step-by-step derivation
      1. Applied rewrites72.1%

        \[\leadsto \mathsf{fma}\left(\frac{\beta - \alpha}{\beta - \color{blue}{-2}}, 0.5, 0.5\right) \]
    7. Recombined 2 regimes into one program.
    8. Add Preprocessing

    Alternative 6: 98.0% accurate, 0.5× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \leq 0.0002:\\ \;\;\;\;0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{\beta}{2 + \beta}, 0.5, 0.5\right)\\ \end{array} \end{array} \]
    (FPCore (alpha beta)
     :precision binary64
     (if (<= (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0) 0.0002)
       (* 0.5 (/ (+ 2.0 (* 2.0 beta)) alpha))
       (fma (/ beta (+ 2.0 beta)) 0.5 0.5)))
    double code(double alpha, double beta) {
    	double tmp;
    	if (((((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0) <= 0.0002) {
    		tmp = 0.5 * ((2.0 + (2.0 * beta)) / alpha);
    	} else {
    		tmp = fma((beta / (2.0 + beta)), 0.5, 0.5);
    	}
    	return tmp;
    }
    
    function code(alpha, beta)
    	tmp = 0.0
    	if (Float64(Float64(Float64(Float64(beta - alpha) / Float64(Float64(alpha + beta) + 2.0)) + 1.0) / 2.0) <= 0.0002)
    		tmp = Float64(0.5 * Float64(Float64(2.0 + Float64(2.0 * beta)) / alpha));
    	else
    		tmp = fma(Float64(beta / Float64(2.0 + beta)), 0.5, 0.5);
    	end
    	return tmp
    end
    
    code[alpha_, beta_] := If[LessEqual[N[(N[(N[(N[(beta - alpha), $MachinePrecision] / N[(N[(alpha + beta), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / 2.0), $MachinePrecision], 0.0002], N[(0.5 * N[(N[(2.0 + N[(2.0 * beta), $MachinePrecision]), $MachinePrecision] / alpha), $MachinePrecision]), $MachinePrecision], N[(N[(beta / N[(2.0 + beta), $MachinePrecision]), $MachinePrecision] * 0.5 + 0.5), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \leq 0.0002:\\
    \;\;\;\;0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha}\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{fma}\left(\frac{\beta}{2 + \beta}, 0.5, 0.5\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64)) < 2.0000000000000001e-4

      1. Initial program 74.9%

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

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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \color{blue}{\left(\frac{\alpha}{\left(\alpha + \beta\right) + 2} - 1\right)}}{2} \]
        13. lower-/.f6475.7

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

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

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

          \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\color{blue}{\left(\alpha + \beta\right) - \left(\mathsf{neg}\left(2\right)\right)}} - 1\right)}{2} \]
        17. metadata-eval75.7

          \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\left(\alpha + \beta\right) - \color{blue}{-2}} - 1\right)}{2} \]
      3. Applied rewrites75.7%

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

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

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

          \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \color{blue}{\left(\mathsf{neg}\left(\left(1 - \frac{\alpha}{\left(\alpha + \beta\right) - -2}\right)\right)\right)}}{2} \]
        4. add-flip-revN/A

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

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

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

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

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

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

          \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{1}{\left(\alpha + \beta\right) - -2}, \beta, \mathsf{neg}\left(\left(\frac{\alpha}{\left(\alpha + \beta\right) - -2} - 1\right)\right)\right)}}{2} \]
      5. Applied rewrites75.7%

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{-1}{\left(-2 - \beta\right) - \alpha}, \beta, 1 - \frac{\alpha}{\beta - \left(-2 - \alpha\right)}\right)}}{2} \]
      6. Taylor expanded in alpha around inf

        \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
      7. Step-by-step derivation
        1. lower-*.f64N/A

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

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

          \[\leadsto \frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha} \]
        4. lower-*.f6429.1

          \[\leadsto 0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha} \]
      8. Applied rewrites29.1%

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

      if 2.0000000000000001e-4 < (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64))

      1. Initial program 74.9%

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

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

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

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

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

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

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

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

          \[\leadsto \mathsf{fma}\left(\frac{\mathsf{neg}\left(\color{blue}{\left(\beta - \alpha\right)}\right)}{\mathsf{neg}\left(\left(\left(\alpha + \beta\right) + 2\right)\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
        9. sub-negate-revN/A

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

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

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

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

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

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

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

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

          \[\leadsto \mathsf{fma}\left(\frac{\alpha - \beta}{-2 - \left(\alpha + \beta\right)}, \color{blue}{\frac{1}{2}}, \frac{1}{2}\right) \]
        18. metadata-eval74.9

          \[\leadsto \mathsf{fma}\left(\frac{\alpha - \beta}{-2 - \left(\alpha + \beta\right)}, 0.5, \color{blue}{0.5}\right) \]
      3. Applied rewrites74.9%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\alpha - \beta}{-2 - \left(\alpha + \beta\right)}, 0.5, 0.5\right)} \]
      4. Applied rewrites74.9%

        \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{\beta - \alpha}{\beta - \left(-2 - \alpha\right)}}, 0.5, 0.5\right) \]
      5. Taylor expanded in alpha around 0

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

          \[\leadsto \mathsf{fma}\left(\frac{\beta}{\color{blue}{2 + \beta}}, \frac{1}{2}, \frac{1}{2}\right) \]
        2. lower-+.f6472.8

          \[\leadsto \mathsf{fma}\left(\frac{\beta}{2 + \color{blue}{\beta}}, 0.5, 0.5\right) \]
      7. Applied rewrites72.8%

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

    Alternative 7: 72.8% accurate, 1.5× speedup?

    \[\begin{array}{l} \\ \mathsf{fma}\left(\frac{\beta}{2 + \beta}, 0.5, 0.5\right) \end{array} \]
    (FPCore (alpha beta) :precision binary64 (fma (/ beta (+ 2.0 beta)) 0.5 0.5))
    double code(double alpha, double beta) {
    	return fma((beta / (2.0 + beta)), 0.5, 0.5);
    }
    
    function code(alpha, beta)
    	return fma(Float64(beta / Float64(2.0 + beta)), 0.5, 0.5)
    end
    
    code[alpha_, beta_] := N[(N[(beta / N[(2.0 + beta), $MachinePrecision]), $MachinePrecision] * 0.5 + 0.5), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \mathsf{fma}\left(\frac{\beta}{2 + \beta}, 0.5, 0.5\right)
    \end{array}
    
    Derivation
    1. Initial program 74.9%

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\frac{\mathsf{neg}\left(\color{blue}{\left(\beta - \alpha\right)}\right)}{\mathsf{neg}\left(\left(\left(\alpha + \beta\right) + 2\right)\right)}, \frac{1}{2}, \frac{1}{2}\right) \]
      9. sub-negate-revN/A

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\frac{\alpha - \beta}{-2 - \left(\alpha + \beta\right)}, \color{blue}{\frac{1}{2}}, \frac{1}{2}\right) \]
      18. metadata-eval74.9

        \[\leadsto \mathsf{fma}\left(\frac{\alpha - \beta}{-2 - \left(\alpha + \beta\right)}, 0.5, \color{blue}{0.5}\right) \]
    3. Applied rewrites74.9%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\alpha - \beta}{-2 - \left(\alpha + \beta\right)}, 0.5, 0.5\right)} \]
    4. Applied rewrites74.9%

      \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{\beta - \alpha}{\beta - \left(-2 - \alpha\right)}}, 0.5, 0.5\right) \]
    5. Taylor expanded in alpha around 0

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

        \[\leadsto \mathsf{fma}\left(\frac{\beta}{\color{blue}{2 + \beta}}, \frac{1}{2}, \frac{1}{2}\right) \]
      2. lower-+.f6472.8

        \[\leadsto \mathsf{fma}\left(\frac{\beta}{2 + \color{blue}{\beta}}, 0.5, 0.5\right) \]
    7. Applied rewrites72.8%

      \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{\beta}{2 + \beta}}, 0.5, 0.5\right) \]
    8. Add Preprocessing

    Alternative 8: 36.6% accurate, 4.3× speedup?

    \[\begin{array}{l} \\ \frac{2}{2} \end{array} \]
    (FPCore (alpha beta) :precision binary64 (/ 2.0 2.0))
    double code(double alpha, double beta) {
    	return 2.0 / 2.0;
    }
    
    module fmin_fmax_functions
        implicit none
        private
        public fmax
        public fmin
    
        interface fmax
            module procedure fmax88
            module procedure fmax44
            module procedure fmax84
            module procedure fmax48
        end interface
        interface fmin
            module procedure fmin88
            module procedure fmin44
            module procedure fmin84
            module procedure fmin48
        end interface
    contains
        real(8) function fmax88(x, y) result (res)
            real(8), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(x, max(x, y), y /= y), x /= x)
        end function
        real(4) function fmax44(x, y) result (res)
            real(4), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(y, merge(x, max(x, y), y /= y), x /= x)
        end function
        real(8) function fmax84(x, y) result(res)
            real(8), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
        end function
        real(8) function fmax48(x, y) result(res)
            real(4), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
        end function
        real(8) function fmin88(x, y) result (res)
            real(8), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(x, min(x, y), y /= y), x /= x)
        end function
        real(4) function fmin44(x, y) result (res)
            real(4), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(y, merge(x, min(x, y), y /= y), x /= x)
        end function
        real(8) function fmin84(x, y) result(res)
            real(8), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
        end function
        real(8) function fmin48(x, y) result(res)
            real(4), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
        end function
    end module
    
    real(8) function code(alpha, beta)
    use fmin_fmax_functions
        real(8), intent (in) :: alpha
        real(8), intent (in) :: beta
        code = 2.0d0 / 2.0d0
    end function
    
    public static double code(double alpha, double beta) {
    	return 2.0 / 2.0;
    }
    
    def code(alpha, beta):
    	return 2.0 / 2.0
    
    function code(alpha, beta)
    	return Float64(2.0 / 2.0)
    end
    
    function tmp = code(alpha, beta)
    	tmp = 2.0 / 2.0;
    end
    
    code[alpha_, beta_] := N[(2.0 / 2.0), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{2}{2}
    \end{array}
    
    Derivation
    1. Initial program 74.9%

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \color{blue}{\left(\frac{\alpha}{\left(\alpha + \beta\right) + 2} - 1\right)}}{2} \]
      13. lower-/.f6475.7

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\color{blue}{\left(\alpha + \beta\right) - \left(\mathsf{neg}\left(2\right)\right)}} - 1\right)}{2} \]
      17. metadata-eval75.7

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \left(\frac{\alpha}{\left(\alpha + \beta\right) - \color{blue}{-2}} - 1\right)}{2} \]
    3. Applied rewrites75.7%

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

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

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

        \[\leadsto \frac{\frac{\beta}{\left(\alpha + \beta\right) - -2} - \color{blue}{\left(\mathsf{neg}\left(\left(1 - \frac{\alpha}{\left(\alpha + \beta\right) - -2}\right)\right)\right)}}{2} \]
      4. add-flip-revN/A

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

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

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

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

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

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

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{1}{\left(\alpha + \beta\right) - -2}, \beta, \mathsf{neg}\left(\left(\frac{\alpha}{\left(\alpha + \beta\right) - -2} - 1\right)\right)\right)}}{2} \]
    5. Applied rewrites75.7%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{-1}{\left(-2 - \beta\right) - \alpha}, \beta, 1 - \frac{\alpha}{\beta - \left(-2 - \alpha\right)}\right)}}{2} \]
    6. Taylor expanded in beta around inf

      \[\leadsto \frac{\color{blue}{2}}{2} \]
    7. Step-by-step derivation
      1. Applied rewrites36.6%

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

      Reproduce

      ?
      herbie shell --seed 2025140 
      (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))