
(FPCore (alpha beta) :precision binary64 (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0))
double code(double alpha, double beta) {
return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
}
real(8) function code(alpha, beta)
real(8), intent (in) :: alpha
real(8), intent (in) :: beta
code = (((beta - alpha) / ((alpha + beta) + 2.0d0)) + 1.0d0) / 2.0d0
end function
public static double code(double alpha, double beta) {
return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
}
def code(alpha, beta): return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0
function code(alpha, beta) return Float64(Float64(Float64(Float64(beta - alpha) / Float64(Float64(alpha + beta) + 2.0)) + 1.0) / 2.0) end
function tmp = code(alpha, beta) tmp = (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0; end
code[alpha_, beta_] := N[(N[(N[(N[(beta - alpha), $MachinePrecision] / N[(N[(alpha + beta), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / 2.0), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (alpha beta) :precision binary64 (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0))
double code(double alpha, double beta) {
return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
}
real(8) function code(alpha, beta)
real(8), intent (in) :: alpha
real(8), intent (in) :: beta
code = (((beta - alpha) / ((alpha + beta) + 2.0d0)) + 1.0d0) / 2.0d0
end function
public static double code(double alpha, double beta) {
return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
}
def code(alpha, beta): return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0
function code(alpha, beta) return Float64(Float64(Float64(Float64(beta - alpha) / Float64(Float64(alpha + beta) + 2.0)) + 1.0) / 2.0) end
function tmp = code(alpha, beta) tmp = (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0; end
code[alpha_, beta_] := N[(N[(N[(N[(beta - alpha), $MachinePrecision] / N[(N[(alpha + beta), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / 2.0), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2}
\end{array}
(FPCore (alpha beta)
:precision binary64
(let* ((t_0 (/ (- beta alpha) (+ (+ beta alpha) 2.0))))
(if (<= t_0 -0.9998)
(/
(fma
(/ (- (- -2.0 beta) beta) alpha)
(/ (+ beta 2.0) alpha)
(/ (+ beta (+ beta 2.0)) alpha))
2.0)
(/ (+ t_0 1.0) 2.0))))
double code(double alpha, double beta) {
double t_0 = (beta - alpha) / ((beta + alpha) + 2.0);
double tmp;
if (t_0 <= -0.9998) {
tmp = fma((((-2.0 - beta) - beta) / alpha), ((beta + 2.0) / alpha), ((beta + (beta + 2.0)) / alpha)) / 2.0;
} else {
tmp = (t_0 + 1.0) / 2.0;
}
return tmp;
}
function code(alpha, beta) t_0 = Float64(Float64(beta - alpha) / Float64(Float64(beta + alpha) + 2.0)) tmp = 0.0 if (t_0 <= -0.9998) tmp = Float64(fma(Float64(Float64(Float64(-2.0 - beta) - beta) / alpha), Float64(Float64(beta + 2.0) / alpha), Float64(Float64(beta + Float64(beta + 2.0)) / alpha)) / 2.0); else tmp = Float64(Float64(t_0 + 1.0) / 2.0); end return tmp end
code[alpha_, beta_] := Block[{t$95$0 = N[(N[(beta - alpha), $MachinePrecision] / N[(N[(beta + alpha), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -0.9998], N[(N[(N[(N[(N[(-2.0 - beta), $MachinePrecision] - beta), $MachinePrecision] / alpha), $MachinePrecision] * N[(N[(beta + 2.0), $MachinePrecision] / alpha), $MachinePrecision] + N[(N[(beta + N[(beta + 2.0), $MachinePrecision]), $MachinePrecision] / alpha), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision], N[(N[(t$95$0 + 1.0), $MachinePrecision] / 2.0), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2}\\
\mathbf{if}\;t_0 \leq -0.9998:\\
\;\;\;\;\frac{\mathsf{fma}\left(\frac{\left(-2 - \beta\right) - \beta}{\alpha}, \frac{\beta + 2}{\alpha}, \frac{\beta + \left(\beta + 2\right)}{\alpha}\right)}{2}\\
\mathbf{else}:\\
\;\;\;\;\frac{t_0 + 1}{2}\\
\end{array}
\end{array}
if (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) 2)) < -0.99980000000000002Initial program 5.9%
+-commutative5.9%
Simplified5.9%
Taylor expanded in alpha around -inf 92.5%
Simplified100.0%
if -0.99980000000000002 < (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) 2)) Initial program 99.9%
Final simplification99.9%
(FPCore (alpha beta)
:precision binary64
(let* ((t_0 (/ (- beta alpha) (+ (+ beta alpha) 2.0))))
(if (<= t_0 -0.9998)
(/ (/ (+ 2.0 (* beta 2.0)) alpha) 2.0)
(/ (+ t_0 1.0) 2.0))))
double code(double alpha, double beta) {
double t_0 = (beta - alpha) / ((beta + alpha) + 2.0);
double tmp;
if (t_0 <= -0.9998) {
tmp = ((2.0 + (beta * 2.0)) / alpha) / 2.0;
} else {
tmp = (t_0 + 1.0) / 2.0;
}
return tmp;
}
real(8) function code(alpha, beta)
real(8), intent (in) :: alpha
real(8), intent (in) :: beta
real(8) :: t_0
real(8) :: tmp
t_0 = (beta - alpha) / ((beta + alpha) + 2.0d0)
if (t_0 <= (-0.9998d0)) then
tmp = ((2.0d0 + (beta * 2.0d0)) / alpha) / 2.0d0
else
tmp = (t_0 + 1.0d0) / 2.0d0
end if
code = tmp
end function
public static double code(double alpha, double beta) {
double t_0 = (beta - alpha) / ((beta + alpha) + 2.0);
double tmp;
if (t_0 <= -0.9998) {
tmp = ((2.0 + (beta * 2.0)) / alpha) / 2.0;
} else {
tmp = (t_0 + 1.0) / 2.0;
}
return tmp;
}
def code(alpha, beta): t_0 = (beta - alpha) / ((beta + alpha) + 2.0) tmp = 0 if t_0 <= -0.9998: tmp = ((2.0 + (beta * 2.0)) / alpha) / 2.0 else: tmp = (t_0 + 1.0) / 2.0 return tmp
function code(alpha, beta) t_0 = Float64(Float64(beta - alpha) / Float64(Float64(beta + alpha) + 2.0)) tmp = 0.0 if (t_0 <= -0.9998) tmp = Float64(Float64(Float64(2.0 + Float64(beta * 2.0)) / alpha) / 2.0); else tmp = Float64(Float64(t_0 + 1.0) / 2.0); end return tmp end
function tmp_2 = code(alpha, beta) t_0 = (beta - alpha) / ((beta + alpha) + 2.0); tmp = 0.0; if (t_0 <= -0.9998) tmp = ((2.0 + (beta * 2.0)) / alpha) / 2.0; else tmp = (t_0 + 1.0) / 2.0; end tmp_2 = tmp; end
code[alpha_, beta_] := Block[{t$95$0 = N[(N[(beta - alpha), $MachinePrecision] / N[(N[(beta + alpha), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -0.9998], N[(N[(N[(2.0 + N[(beta * 2.0), $MachinePrecision]), $MachinePrecision] / alpha), $MachinePrecision] / 2.0), $MachinePrecision], N[(N[(t$95$0 + 1.0), $MachinePrecision] / 2.0), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2}\\
\mathbf{if}\;t_0 \leq -0.9998:\\
\;\;\;\;\frac{\frac{2 + \beta \cdot 2}{\alpha}}{2}\\
\mathbf{else}:\\
\;\;\;\;\frac{t_0 + 1}{2}\\
\end{array}
\end{array}
if (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) 2)) < -0.99980000000000002Initial program 5.9%
+-commutative5.9%
Simplified5.9%
Taylor expanded in alpha around inf 99.4%
if -0.99980000000000002 < (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) 2)) Initial program 99.9%
Final simplification99.8%
(FPCore (alpha beta) :precision binary64 (if (<= alpha 7.2e+21) (/ (+ 1.0 (/ beta (+ beta 2.0))) 2.0) (/ (/ (+ beta 2.0) alpha) 2.0)))
double code(double alpha, double beta) {
double tmp;
if (alpha <= 7.2e+21) {
tmp = (1.0 + (beta / (beta + 2.0))) / 2.0;
} else {
tmp = ((beta + 2.0) / alpha) / 2.0;
}
return tmp;
}
real(8) function code(alpha, beta)
real(8), intent (in) :: alpha
real(8), intent (in) :: beta
real(8) :: tmp
if (alpha <= 7.2d+21) then
tmp = (1.0d0 + (beta / (beta + 2.0d0))) / 2.0d0
else
tmp = ((beta + 2.0d0) / alpha) / 2.0d0
end if
code = tmp
end function
public static double code(double alpha, double beta) {
double tmp;
if (alpha <= 7.2e+21) {
tmp = (1.0 + (beta / (beta + 2.0))) / 2.0;
} else {
tmp = ((beta + 2.0) / alpha) / 2.0;
}
return tmp;
}
def code(alpha, beta): tmp = 0 if alpha <= 7.2e+21: tmp = (1.0 + (beta / (beta + 2.0))) / 2.0 else: tmp = ((beta + 2.0) / alpha) / 2.0 return tmp
function code(alpha, beta) tmp = 0.0 if (alpha <= 7.2e+21) tmp = Float64(Float64(1.0 + Float64(beta / Float64(beta + 2.0))) / 2.0); else tmp = Float64(Float64(Float64(beta + 2.0) / alpha) / 2.0); end return tmp end
function tmp_2 = code(alpha, beta) tmp = 0.0; if (alpha <= 7.2e+21) tmp = (1.0 + (beta / (beta + 2.0))) / 2.0; else tmp = ((beta + 2.0) / alpha) / 2.0; end tmp_2 = tmp; end
code[alpha_, beta_] := If[LessEqual[alpha, 7.2e+21], N[(N[(1.0 + N[(beta / N[(beta + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision], N[(N[(N[(beta + 2.0), $MachinePrecision] / alpha), $MachinePrecision] / 2.0), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\alpha \leq 7.2 \cdot 10^{+21}:\\
\;\;\;\;\frac{1 + \frac{\beta}{\beta + 2}}{2}\\
\mathbf{else}:\\
\;\;\;\;\frac{\frac{\beta + 2}{\alpha}}{2}\\
\end{array}
\end{array}
if alpha < 7.2e21Initial program 99.7%
+-commutative99.7%
Simplified99.7%
Taylor expanded in alpha around 0 97.5%
if 7.2e21 < alpha Initial program 20.6%
+-commutative20.6%
Simplified20.6%
clear-num20.7%
associate-/r/20.6%
fma-def20.0%
associate-+l+20.0%
Applied egg-rr20.0%
Taylor expanded in beta around 0 4.9%
+-commutative4.9%
Simplified4.9%
Taylor expanded in alpha around inf 66.5%
Final simplification87.9%
(FPCore (alpha beta) :precision binary64 (if (<= alpha 7.6e+24) (/ (+ 1.0 (/ beta (+ beta 2.0))) 2.0) (/ (/ (+ 2.0 (* beta 2.0)) alpha) 2.0)))
double code(double alpha, double beta) {
double tmp;
if (alpha <= 7.6e+24) {
tmp = (1.0 + (beta / (beta + 2.0))) / 2.0;
} else {
tmp = ((2.0 + (beta * 2.0)) / alpha) / 2.0;
}
return tmp;
}
real(8) function code(alpha, beta)
real(8), intent (in) :: alpha
real(8), intent (in) :: beta
real(8) :: tmp
if (alpha <= 7.6d+24) then
tmp = (1.0d0 + (beta / (beta + 2.0d0))) / 2.0d0
else
tmp = ((2.0d0 + (beta * 2.0d0)) / alpha) / 2.0d0
end if
code = tmp
end function
public static double code(double alpha, double beta) {
double tmp;
if (alpha <= 7.6e+24) {
tmp = (1.0 + (beta / (beta + 2.0))) / 2.0;
} else {
tmp = ((2.0 + (beta * 2.0)) / alpha) / 2.0;
}
return tmp;
}
def code(alpha, beta): tmp = 0 if alpha <= 7.6e+24: tmp = (1.0 + (beta / (beta + 2.0))) / 2.0 else: tmp = ((2.0 + (beta * 2.0)) / alpha) / 2.0 return tmp
function code(alpha, beta) tmp = 0.0 if (alpha <= 7.6e+24) tmp = Float64(Float64(1.0 + Float64(beta / Float64(beta + 2.0))) / 2.0); else tmp = Float64(Float64(Float64(2.0 + Float64(beta * 2.0)) / alpha) / 2.0); end return tmp end
function tmp_2 = code(alpha, beta) tmp = 0.0; if (alpha <= 7.6e+24) tmp = (1.0 + (beta / (beta + 2.0))) / 2.0; else tmp = ((2.0 + (beta * 2.0)) / alpha) / 2.0; end tmp_2 = tmp; end
code[alpha_, beta_] := If[LessEqual[alpha, 7.6e+24], N[(N[(1.0 + N[(beta / N[(beta + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision], N[(N[(N[(2.0 + N[(beta * 2.0), $MachinePrecision]), $MachinePrecision] / alpha), $MachinePrecision] / 2.0), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\alpha \leq 7.6 \cdot 10^{+24}:\\
\;\;\;\;\frac{1 + \frac{\beta}{\beta + 2}}{2}\\
\mathbf{else}:\\
\;\;\;\;\frac{\frac{2 + \beta \cdot 2}{\alpha}}{2}\\
\end{array}
\end{array}
if alpha < 7.6000000000000003e24Initial program 99.7%
+-commutative99.7%
Simplified99.7%
Taylor expanded in alpha around 0 97.5%
if 7.6000000000000003e24 < alpha Initial program 20.6%
+-commutative20.6%
Simplified20.6%
Taylor expanded in alpha around inf 84.9%
Final simplification93.6%
(FPCore (alpha beta) :precision binary64 (if (<= beta 2.0) (/ (+ 1.0 (* beta 0.5)) 2.0) (+ 1.0 (/ -1.0 beta))))
double code(double alpha, double beta) {
double tmp;
if (beta <= 2.0) {
tmp = (1.0 + (beta * 0.5)) / 2.0;
} else {
tmp = 1.0 + (-1.0 / beta);
}
return tmp;
}
real(8) function code(alpha, beta)
real(8), intent (in) :: alpha
real(8), intent (in) :: beta
real(8) :: tmp
if (beta <= 2.0d0) then
tmp = (1.0d0 + (beta * 0.5d0)) / 2.0d0
else
tmp = 1.0d0 + ((-1.0d0) / beta)
end if
code = tmp
end function
public static double code(double alpha, double beta) {
double tmp;
if (beta <= 2.0) {
tmp = (1.0 + (beta * 0.5)) / 2.0;
} else {
tmp = 1.0 + (-1.0 / beta);
}
return tmp;
}
def code(alpha, beta): tmp = 0 if beta <= 2.0: tmp = (1.0 + (beta * 0.5)) / 2.0 else: tmp = 1.0 + (-1.0 / beta) return tmp
function code(alpha, beta) tmp = 0.0 if (beta <= 2.0) tmp = Float64(Float64(1.0 + Float64(beta * 0.5)) / 2.0); else tmp = Float64(1.0 + Float64(-1.0 / beta)); end return tmp end
function tmp_2 = code(alpha, beta) tmp = 0.0; if (beta <= 2.0) tmp = (1.0 + (beta * 0.5)) / 2.0; else tmp = 1.0 + (-1.0 / beta); end tmp_2 = tmp; end
code[alpha_, beta_] := If[LessEqual[beta, 2.0], N[(N[(1.0 + N[(beta * 0.5), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision], N[(1.0 + N[(-1.0 / beta), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\beta \leq 2:\\
\;\;\;\;\frac{1 + \beta \cdot 0.5}{2}\\
\mathbf{else}:\\
\;\;\;\;1 + \frac{-1}{\beta}\\
\end{array}
\end{array}
if beta < 2Initial program 71.4%
+-commutative71.4%
Simplified71.4%
Taylor expanded in alpha around 0 68.9%
Taylor expanded in beta around 0 68.1%
*-commutative68.1%
Simplified68.1%
if 2 < beta Initial program 82.3%
+-commutative82.3%
Simplified82.3%
Taylor expanded in beta around inf 79.8%
Taylor expanded in alpha around 0 80.4%
sub-neg80.4%
distribute-lft-in80.4%
metadata-eval80.4%
associate-*r/80.4%
metadata-eval80.4%
distribute-neg-frac80.4%
metadata-eval80.4%
associate-*r/80.4%
metadata-eval80.4%
Simplified80.4%
Final simplification72.5%
(FPCore (alpha beta) :precision binary64 (if (<= beta 90.0) 0.5 (+ 1.0 (/ -1.0 beta))))
double code(double alpha, double beta) {
double tmp;
if (beta <= 90.0) {
tmp = 0.5;
} else {
tmp = 1.0 + (-1.0 / beta);
}
return tmp;
}
real(8) function code(alpha, beta)
real(8), intent (in) :: alpha
real(8), intent (in) :: beta
real(8) :: tmp
if (beta <= 90.0d0) then
tmp = 0.5d0
else
tmp = 1.0d0 + ((-1.0d0) / beta)
end if
code = tmp
end function
public static double code(double alpha, double beta) {
double tmp;
if (beta <= 90.0) {
tmp = 0.5;
} else {
tmp = 1.0 + (-1.0 / beta);
}
return tmp;
}
def code(alpha, beta): tmp = 0 if beta <= 90.0: tmp = 0.5 else: tmp = 1.0 + (-1.0 / beta) return tmp
function code(alpha, beta) tmp = 0.0 if (beta <= 90.0) tmp = 0.5; else tmp = Float64(1.0 + Float64(-1.0 / beta)); end return tmp end
function tmp_2 = code(alpha, beta) tmp = 0.0; if (beta <= 90.0) tmp = 0.5; else tmp = 1.0 + (-1.0 / beta); end tmp_2 = tmp; end
code[alpha_, beta_] := If[LessEqual[beta, 90.0], 0.5, N[(1.0 + N[(-1.0 / beta), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\beta \leq 90:\\
\;\;\;\;0.5\\
\mathbf{else}:\\
\;\;\;\;1 + \frac{-1}{\beta}\\
\end{array}
\end{array}
if beta < 90Initial program 71.0%
+-commutative71.0%
Simplified71.0%
Taylor expanded in beta around 0 69.6%
+-commutative69.6%
Simplified69.6%
Taylor expanded in alpha around 0 67.2%
if 90 < beta Initial program 83.1%
+-commutative83.1%
Simplified83.1%
Taylor expanded in beta around inf 80.6%
Taylor expanded in alpha around 0 81.2%
sub-neg81.2%
distribute-lft-in81.2%
metadata-eval81.2%
associate-*r/81.2%
metadata-eval81.2%
distribute-neg-frac81.2%
metadata-eval81.2%
associate-*r/81.2%
metadata-eval81.2%
Simplified81.2%
Final simplification72.2%
(FPCore (alpha beta) :precision binary64 (if (<= beta 90.0) 0.5 1.0))
double code(double alpha, double beta) {
double tmp;
if (beta <= 90.0) {
tmp = 0.5;
} else {
tmp = 1.0;
}
return tmp;
}
real(8) function code(alpha, beta)
real(8), intent (in) :: alpha
real(8), intent (in) :: beta
real(8) :: tmp
if (beta <= 90.0d0) then
tmp = 0.5d0
else
tmp = 1.0d0
end if
code = tmp
end function
public static double code(double alpha, double beta) {
double tmp;
if (beta <= 90.0) {
tmp = 0.5;
} else {
tmp = 1.0;
}
return tmp;
}
def code(alpha, beta): tmp = 0 if beta <= 90.0: tmp = 0.5 else: tmp = 1.0 return tmp
function code(alpha, beta) tmp = 0.0 if (beta <= 90.0) tmp = 0.5; else tmp = 1.0; end return tmp end
function tmp_2 = code(alpha, beta) tmp = 0.0; if (beta <= 90.0) tmp = 0.5; else tmp = 1.0; end tmp_2 = tmp; end
code[alpha_, beta_] := If[LessEqual[beta, 90.0], 0.5, 1.0]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\beta \leq 90:\\
\;\;\;\;0.5\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if beta < 90Initial program 71.0%
+-commutative71.0%
Simplified71.0%
Taylor expanded in beta around 0 69.6%
+-commutative69.6%
Simplified69.6%
Taylor expanded in alpha around 0 67.2%
if 90 < beta Initial program 83.1%
+-commutative83.1%
Simplified83.1%
Taylor expanded in beta around inf 80.8%
Final simplification72.0%
(FPCore (alpha beta) :precision binary64 0.5)
double code(double alpha, double beta) {
return 0.5;
}
real(8) function code(alpha, beta)
real(8), intent (in) :: alpha
real(8), intent (in) :: beta
code = 0.5d0
end function
public static double code(double alpha, double beta) {
return 0.5;
}
def code(alpha, beta): return 0.5
function code(alpha, beta) return 0.5 end
function tmp = code(alpha, beta) tmp = 0.5; end
code[alpha_, beta_] := 0.5
\begin{array}{l}
\\
0.5
\end{array}
Initial program 75.3%
+-commutative75.3%
Simplified75.3%
Taylor expanded in beta around 0 49.7%
+-commutative49.7%
Simplified49.7%
Taylor expanded in alpha around 0 49.2%
Final simplification49.2%
herbie shell --seed 2023242
(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))