Average Error: 24.0 → 1.3
Time: 29.3s
Precision: binary64
Cost: 35268
\[\left(\alpha > -1 \land \beta > -1\right) \land i > 0\]
\[\frac{\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{\left(\alpha + \beta\right) + 2 \cdot i}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2} + 1}{2} \]
\[\begin{array}{l} t_0 := \left(\alpha + \beta\right) + 2 \cdot i\\ \mathbf{if}\;\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{t_0}}{2 + t_0} \leq -0.9999998:\\ \;\;\;\;\frac{\frac{\left(\beta - \beta\right) + \left(i \cdot 4 + \left(2 + \beta \cdot 2\right)\right)}{\alpha}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{{\left({\left(\mathsf{fma}\left(\alpha + \beta, \frac{\frac{\beta - \alpha}{\mathsf{fma}\left(2, i, \alpha + \beta\right)}}{\beta + \left(\alpha + \mathsf{fma}\left(2, i, 2\right)\right)}, 1\right)\right)}^{3}\right)}^{0.3333333333333333}}{2}\\ \end{array} \]
(FPCore (alpha beta i)
 :precision binary64
 (/
  (+
   (/
    (/ (* (+ alpha beta) (- beta alpha)) (+ (+ alpha beta) (* 2.0 i)))
    (+ (+ (+ alpha beta) (* 2.0 i)) 2.0))
   1.0)
  2.0))
(FPCore (alpha beta i)
 :precision binary64
 (let* ((t_0 (+ (+ alpha beta) (* 2.0 i))))
   (if (<=
        (/ (/ (* (+ alpha beta) (- beta alpha)) t_0) (+ 2.0 t_0))
        -0.9999998)
     (/ (/ (+ (- beta beta) (+ (* i 4.0) (+ 2.0 (* beta 2.0)))) alpha) 2.0)
     (/
      (pow
       (pow
        (fma
         (+ alpha beta)
         (/
          (/ (- beta alpha) (fma 2.0 i (+ alpha beta)))
          (+ beta (+ alpha (fma 2.0 i 2.0))))
         1.0)
        3.0)
       0.3333333333333333)
      2.0))))
double code(double alpha, double beta, double i) {
	return (((((alpha + beta) * (beta - alpha)) / ((alpha + beta) + (2.0 * i))) / (((alpha + beta) + (2.0 * i)) + 2.0)) + 1.0) / 2.0;
}
double code(double alpha, double beta, double i) {
	double t_0 = (alpha + beta) + (2.0 * i);
	double tmp;
	if (((((alpha + beta) * (beta - alpha)) / t_0) / (2.0 + t_0)) <= -0.9999998) {
		tmp = (((beta - beta) + ((i * 4.0) + (2.0 + (beta * 2.0)))) / alpha) / 2.0;
	} else {
		tmp = pow(pow(fma((alpha + beta), (((beta - alpha) / fma(2.0, i, (alpha + beta))) / (beta + (alpha + fma(2.0, i, 2.0)))), 1.0), 3.0), 0.3333333333333333) / 2.0;
	}
	return tmp;
}
function code(alpha, beta, i)
	return Float64(Float64(Float64(Float64(Float64(Float64(alpha + beta) * Float64(beta - alpha)) / Float64(Float64(alpha + beta) + Float64(2.0 * i))) / Float64(Float64(Float64(alpha + beta) + Float64(2.0 * i)) + 2.0)) + 1.0) / 2.0)
end
function code(alpha, beta, i)
	t_0 = Float64(Float64(alpha + beta) + Float64(2.0 * i))
	tmp = 0.0
	if (Float64(Float64(Float64(Float64(alpha + beta) * Float64(beta - alpha)) / t_0) / Float64(2.0 + t_0)) <= -0.9999998)
		tmp = Float64(Float64(Float64(Float64(beta - beta) + Float64(Float64(i * 4.0) + Float64(2.0 + Float64(beta * 2.0)))) / alpha) / 2.0);
	else
		tmp = Float64(((fma(Float64(alpha + beta), Float64(Float64(Float64(beta - alpha) / fma(2.0, i, Float64(alpha + beta))) / Float64(beta + Float64(alpha + fma(2.0, i, 2.0)))), 1.0) ^ 3.0) ^ 0.3333333333333333) / 2.0);
	end
	return tmp
end
code[alpha_, beta_, i_] := N[(N[(N[(N[(N[(N[(alpha + beta), $MachinePrecision] * N[(beta - alpha), $MachinePrecision]), $MachinePrecision] / N[(N[(alpha + beta), $MachinePrecision] + N[(2.0 * i), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(alpha + beta), $MachinePrecision] + N[(2.0 * i), $MachinePrecision]), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / 2.0), $MachinePrecision]
code[alpha_, beta_, i_] := Block[{t$95$0 = N[(N[(alpha + beta), $MachinePrecision] + N[(2.0 * i), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(N[(N[(alpha + beta), $MachinePrecision] * N[(beta - alpha), $MachinePrecision]), $MachinePrecision] / t$95$0), $MachinePrecision] / N[(2.0 + t$95$0), $MachinePrecision]), $MachinePrecision], -0.9999998], N[(N[(N[(N[(beta - beta), $MachinePrecision] + N[(N[(i * 4.0), $MachinePrecision] + N[(2.0 + N[(beta * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / alpha), $MachinePrecision] / 2.0), $MachinePrecision], N[(N[Power[N[Power[N[(N[(alpha + beta), $MachinePrecision] * N[(N[(N[(beta - alpha), $MachinePrecision] / N[(2.0 * i + N[(alpha + beta), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(beta + N[(alpha + N[(2.0 * i + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision], 3.0], $MachinePrecision], 0.3333333333333333], $MachinePrecision] / 2.0), $MachinePrecision]]]
\frac{\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{\left(\alpha + \beta\right) + 2 \cdot i}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2} + 1}{2}
\begin{array}{l}
t_0 := \left(\alpha + \beta\right) + 2 \cdot i\\
\mathbf{if}\;\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{t_0}}{2 + t_0} \leq -0.9999998:\\
\;\;\;\;\frac{\frac{\left(\beta - \beta\right) + \left(i \cdot 4 + \left(2 + \beta \cdot 2\right)\right)}{\alpha}}{2}\\

\mathbf{else}:\\
\;\;\;\;\frac{{\left({\left(\mathsf{fma}\left(\alpha + \beta, \frac{\frac{\beta - \alpha}{\mathsf{fma}\left(2, i, \alpha + \beta\right)}}{\beta + \left(\alpha + \mathsf{fma}\left(2, i, 2\right)\right)}, 1\right)\right)}^{3}\right)}^{0.3333333333333333}}{2}\\


\end{array}

Error

Derivation

  1. Split input into 2 regimes
  2. if (/.f64 (/.f64 (*.f64 (+.f64 alpha beta) (-.f64 beta alpha)) (+.f64 (+.f64 alpha beta) (*.f64 2 i))) (+.f64 (+.f64 (+.f64 alpha beta) (*.f64 2 i)) 2)) < -0.999999799999999994

    1. Initial program 62.7

      \[\frac{\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{\left(\alpha + \beta\right) + 2 \cdot i}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2} + 1}{2} \]
    2. Simplified54.7

      \[\leadsto \color{blue}{\frac{\frac{\alpha + \beta}{\left(\alpha + \left(\beta + \mathsf{fma}\left(2, i, 2\right)\right)\right) \cdot \frac{\mathsf{fma}\left(2, i, \alpha + \beta\right)}{\beta - \alpha}} + 1}{2}} \]
      Proof
      (/.f64 (+.f64 (/.f64 (+.f64 alpha beta) (*.f64 (+.f64 alpha (+.f64 beta (fma.f64 2 i 2))) (/.f64 (fma.f64 2 i (+.f64 alpha beta)) (-.f64 beta alpha)))) 1) 2): 0 points increase in error, 0 points decrease in error
      (/.f64 (+.f64 (/.f64 (+.f64 alpha beta) (*.f64 (+.f64 alpha (+.f64 beta (Rewrite<= fma-def_binary64 (+.f64 (*.f64 2 i) 2)))) (/.f64 (fma.f64 2 i (+.f64 alpha beta)) (-.f64 beta alpha)))) 1) 2): 0 points increase in error, 0 points decrease in error
      (/.f64 (+.f64 (/.f64 (+.f64 alpha beta) (*.f64 (Rewrite<= associate-+l+_binary64 (+.f64 (+.f64 alpha beta) (+.f64 (*.f64 2 i) 2))) (/.f64 (fma.f64 2 i (+.f64 alpha beta)) (-.f64 beta alpha)))) 1) 2): 0 points increase in error, 0 points decrease in error
      (/.f64 (+.f64 (/.f64 (+.f64 alpha beta) (*.f64 (Rewrite<= associate-+l+_binary64 (+.f64 (+.f64 (+.f64 alpha beta) (*.f64 2 i)) 2)) (/.f64 (fma.f64 2 i (+.f64 alpha beta)) (-.f64 beta alpha)))) 1) 2): 0 points increase in error, 0 points decrease in error
      (/.f64 (+.f64 (/.f64 (+.f64 alpha beta) (*.f64 (+.f64 (+.f64 (+.f64 alpha beta) (*.f64 2 i)) 2) (/.f64 (Rewrite<= fma-def_binary64 (+.f64 (*.f64 2 i) (+.f64 alpha beta))) (-.f64 beta alpha)))) 1) 2): 0 points increase in error, 0 points decrease in error
      (/.f64 (+.f64 (/.f64 (+.f64 alpha beta) (*.f64 (+.f64 (+.f64 (+.f64 alpha beta) (*.f64 2 i)) 2) (/.f64 (Rewrite<= +-commutative_binary64 (+.f64 (+.f64 alpha beta) (*.f64 2 i))) (-.f64 beta alpha)))) 1) 2): 0 points increase in error, 0 points decrease in error
      (/.f64 (+.f64 (Rewrite<= associate-/l/_binary64 (/.f64 (/.f64 (+.f64 alpha beta) (/.f64 (+.f64 (+.f64 alpha beta) (*.f64 2 i)) (-.f64 beta alpha))) (+.f64 (+.f64 (+.f64 alpha beta) (*.f64 2 i)) 2))) 1) 2): 2 points increase in error, 0 points decrease in error
      (/.f64 (+.f64 (/.f64 (Rewrite<= associate-/l*_binary64 (/.f64 (*.f64 (+.f64 alpha beta) (-.f64 beta alpha)) (+.f64 (+.f64 alpha beta) (*.f64 2 i)))) (+.f64 (+.f64 (+.f64 alpha beta) (*.f64 2 i)) 2)) 1) 2): 84 points increase in error, 1 points decrease in error
    3. Taylor expanded in alpha around inf 5.5

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

    if -0.999999799999999994 < (/.f64 (/.f64 (*.f64 (+.f64 alpha beta) (-.f64 beta alpha)) (+.f64 (+.f64 alpha beta) (*.f64 2 i))) (+.f64 (+.f64 (+.f64 alpha beta) (*.f64 2 i)) 2))

    1. Initial program 13.0

      \[\frac{\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{\left(\alpha + \beta\right) + 2 \cdot i}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2} + 1}{2} \]
    2. Simplified0.1

      \[\leadsto \color{blue}{\frac{\frac{\alpha + \beta}{\left(\alpha + \left(\beta + \mathsf{fma}\left(2, i, 2\right)\right)\right) \cdot \frac{\mathsf{fma}\left(2, i, \alpha + \beta\right)}{\beta - \alpha}} + 1}{2}} \]
      Proof
      (/.f64 (+.f64 (/.f64 (+.f64 alpha beta) (*.f64 (+.f64 alpha (+.f64 beta (fma.f64 2 i 2))) (/.f64 (fma.f64 2 i (+.f64 alpha beta)) (-.f64 beta alpha)))) 1) 2): 0 points increase in error, 0 points decrease in error
      (/.f64 (+.f64 (/.f64 (+.f64 alpha beta) (*.f64 (+.f64 alpha (+.f64 beta (Rewrite<= fma-def_binary64 (+.f64 (*.f64 2 i) 2)))) (/.f64 (fma.f64 2 i (+.f64 alpha beta)) (-.f64 beta alpha)))) 1) 2): 0 points increase in error, 0 points decrease in error
      (/.f64 (+.f64 (/.f64 (+.f64 alpha beta) (*.f64 (Rewrite<= associate-+l+_binary64 (+.f64 (+.f64 alpha beta) (+.f64 (*.f64 2 i) 2))) (/.f64 (fma.f64 2 i (+.f64 alpha beta)) (-.f64 beta alpha)))) 1) 2): 0 points increase in error, 0 points decrease in error
      (/.f64 (+.f64 (/.f64 (+.f64 alpha beta) (*.f64 (Rewrite<= associate-+l+_binary64 (+.f64 (+.f64 (+.f64 alpha beta) (*.f64 2 i)) 2)) (/.f64 (fma.f64 2 i (+.f64 alpha beta)) (-.f64 beta alpha)))) 1) 2): 0 points increase in error, 0 points decrease in error
      (/.f64 (+.f64 (/.f64 (+.f64 alpha beta) (*.f64 (+.f64 (+.f64 (+.f64 alpha beta) (*.f64 2 i)) 2) (/.f64 (Rewrite<= fma-def_binary64 (+.f64 (*.f64 2 i) (+.f64 alpha beta))) (-.f64 beta alpha)))) 1) 2): 0 points increase in error, 0 points decrease in error
      (/.f64 (+.f64 (/.f64 (+.f64 alpha beta) (*.f64 (+.f64 (+.f64 (+.f64 alpha beta) (*.f64 2 i)) 2) (/.f64 (Rewrite<= +-commutative_binary64 (+.f64 (+.f64 alpha beta) (*.f64 2 i))) (-.f64 beta alpha)))) 1) 2): 0 points increase in error, 0 points decrease in error
      (/.f64 (+.f64 (Rewrite<= associate-/l/_binary64 (/.f64 (/.f64 (+.f64 alpha beta) (/.f64 (+.f64 (+.f64 alpha beta) (*.f64 2 i)) (-.f64 beta alpha))) (+.f64 (+.f64 (+.f64 alpha beta) (*.f64 2 i)) 2))) 1) 2): 2 points increase in error, 0 points decrease in error
      (/.f64 (+.f64 (/.f64 (Rewrite<= associate-/l*_binary64 (/.f64 (*.f64 (+.f64 alpha beta) (-.f64 beta alpha)) (+.f64 (+.f64 alpha beta) (*.f64 2 i)))) (+.f64 (+.f64 (+.f64 alpha beta) (*.f64 2 i)) 2)) 1) 2): 84 points increase in error, 1 points decrease in error
    3. Applied egg-rr0.1

      \[\leadsto \frac{\color{blue}{{\left({\left(\mathsf{fma}\left(\alpha + \beta, \frac{\frac{\beta - \alpha}{\mathsf{fma}\left(2, i, \alpha + \beta\right)}}{\beta + \left(\alpha + \mathsf{fma}\left(2, i, 2\right)\right)}, 1\right)\right)}^{3}\right)}^{0.3333333333333333}}}{2} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification1.3

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{\left(\alpha + \beta\right) + 2 \cdot i}}{2 + \left(\left(\alpha + \beta\right) + 2 \cdot i\right)} \leq -0.9999998:\\ \;\;\;\;\frac{\frac{\left(\beta - \beta\right) + \left(i \cdot 4 + \left(2 + \beta \cdot 2\right)\right)}{\alpha}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{{\left({\left(\mathsf{fma}\left(\alpha + \beta, \frac{\frac{\beta - \alpha}{\mathsf{fma}\left(2, i, \alpha + \beta\right)}}{\beta + \left(\alpha + \mathsf{fma}\left(2, i, 2\right)\right)}, 1\right)\right)}^{3}\right)}^{0.3333333333333333}}{2}\\ \end{array} \]

Alternatives

Alternative 1
Error1.3
Cost22340
\[\begin{array}{l} t_0 := \left(\alpha + \beta\right) + 2 \cdot i\\ \mathbf{if}\;\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{t_0}}{2 + t_0} \leq -0.9999998:\\ \;\;\;\;\frac{\frac{\left(\beta - \beta\right) + \left(i \cdot 4 + \left(2 + \beta \cdot 2\right)\right)}{\alpha}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(\alpha + \beta, \frac{\frac{\beta - \alpha}{\alpha + \mathsf{fma}\left(2, i, \beta\right)}}{\alpha + \mathsf{fma}\left(2, i, \beta + 2\right)}, 1\right)}{2}\\ \end{array} \]
Alternative 2
Error1.3
Cost16068
\[\begin{array}{l} t_0 := \left(\alpha + \beta\right) + 2 \cdot i\\ \mathbf{if}\;\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{t_0}}{2 + t_0} \leq -0.9999998:\\ \;\;\;\;\frac{\frac{\left(\beta - \beta\right) + \left(i \cdot 4 + \left(2 + \beta \cdot 2\right)\right)}{\alpha}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{1 + \frac{\alpha + \beta}{\left(\alpha + \left(\beta + \mathsf{fma}\left(2, i, 2\right)\right)\right) \cdot \frac{\mathsf{fma}\left(2, i, \alpha + \beta\right)}{\beta - \alpha}}}{2}\\ \end{array} \]
Alternative 3
Error1.3
Cost3524
\[\begin{array}{l} t_0 := \left(\alpha + \beta\right) + 2 \cdot i\\ \mathbf{if}\;\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{t_0}}{2 + t_0} \leq -0.9999998:\\ \;\;\;\;\frac{\frac{\left(\beta - \beta\right) + \left(i \cdot 4 + \left(2 + \beta \cdot 2\right)\right)}{\alpha}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{1 + \frac{\frac{\alpha + \beta}{\frac{\alpha - \left(i \cdot -2 - \beta\right)}{\beta - \alpha}}}{\left(\alpha + \beta\right) + \left(2 + 2 \cdot i\right)}}{2}\\ \end{array} \]
Alternative 4
Error1.8
Cost3268
\[\begin{array}{l} t_0 := \left(\alpha + \beta\right) + 2 \cdot i\\ \mathbf{if}\;\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{t_0}}{2 + t_0} \leq -0.5:\\ \;\;\;\;\frac{\frac{\left(\beta - \beta\right) + \left(i \cdot 4 + \left(2 + \beta \cdot 2\right)\right)}{\alpha}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{1 + \frac{\frac{\alpha + \beta}{\frac{\beta + 2 \cdot i}{\beta}}}{\left(\alpha + \beta\right) + \left(2 + 2 \cdot i\right)}}{2}\\ \end{array} \]
Alternative 5
Error6.8
Cost1220
\[\begin{array}{l} \mathbf{if}\;\alpha \leq 4.5 \cdot 10^{+128}:\\ \;\;\;\;\frac{1 + \frac{\beta}{\beta + \left(2 - i \cdot -4\right)}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\left(\beta - \beta\right) + \left(i \cdot 4 + \left(2 + \beta \cdot 2\right)\right)}{\alpha}}{2}\\ \end{array} \]
Alternative 6
Error12.9
Cost968
\[\begin{array}{l} \mathbf{if}\;\alpha \leq 2 \cdot 10^{-168}:\\ \;\;\;\;\frac{1 + \frac{\beta}{\beta + 2}}{2}\\ \mathbf{elif}\;\alpha \leq 9 \cdot 10^{+124}:\\ \;\;\;\;\frac{1 + \frac{\beta}{\beta + 2 \cdot i}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{2 - i \cdot -4}{\alpha}}{2}\\ \end{array} \]
Alternative 7
Error8.7
Cost964
\[\begin{array}{l} t_0 := 2 - i \cdot -4\\ \mathbf{if}\;\alpha \leq 5.5 \cdot 10^{+129}:\\ \;\;\;\;\frac{1 + \frac{\beta}{\beta + t_0}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{t_0}{\alpha}}{2}\\ \end{array} \]
Alternative 8
Error15.1
Cost708
\[\begin{array}{l} \mathbf{if}\;i \leq 3.2 \cdot 10^{+151}:\\ \;\;\;\;\frac{1 + \frac{\beta}{\beta + 2}}{2}\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \]
Alternative 9
Error13.9
Cost708
\[\begin{array}{l} \mathbf{if}\;\alpha \leq 1.8 \cdot 10^{+126}:\\ \;\;\;\;\frac{1 + \frac{\beta}{\beta + 2}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{2 + \beta \cdot 2}{\alpha}}{2}\\ \end{array} \]
Alternative 10
Error12.6
Cost708
\[\begin{array}{l} \mathbf{if}\;\alpha \leq 1.5 \cdot 10^{+127}:\\ \;\;\;\;\frac{1 + \frac{\beta}{\beta + 2}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{2 - i \cdot -4}{\alpha}}{2}\\ \end{array} \]
Alternative 11
Error17.5
Cost196
\[\begin{array}{l} \mathbf{if}\;\beta \leq 1.85 \cdot 10^{+84}:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]
Alternative 12
Error24.5
Cost64
\[0.5 \]

Error

Reproduce

herbie shell --seed 2022325 
(FPCore (alpha beta i)
  :name "Octave 3.8, jcobi/2"
  :precision binary64
  :pre (and (and (> alpha -1.0) (> beta -1.0)) (> i 0.0))
  (/ (+ (/ (/ (* (+ alpha beta) (- beta alpha)) (+ (+ alpha beta) (* 2.0 i))) (+ (+ (+ alpha beta) (* 2.0 i)) 2.0)) 1.0) 2.0))