Average Error: 24.3 → 1.4
Time: 24.8s
Precision: binary64
\[\alpha > -1 \land \beta > -1 \land i > 0\]
\[\frac{\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{\left(\alpha + \beta\right) + 2 \cdot i}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2} + 1}{2}\]
↓
\[\begin{array}{l} \mathbf{if}\;\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{\left(\alpha + \beta\right) + 2 \cdot i}}{2 + \left(\left(\alpha + \beta\right) + 2 \cdot i\right)} \leq -0.9999999999921052:\\ \;\;\;\;\frac{\left(2 \cdot \frac{\beta}{\alpha} + \left(4 \cdot \frac{i}{\alpha} + \frac{2}{\alpha}\right)\right) - \left(6 \cdot \frac{\beta}{\alpha \cdot \alpha} + \left(12 \cdot \frac{i}{\alpha \cdot \alpha} + \left(12 \cdot \left(\frac{\beta}{\alpha} \cdot \frac{i}{\alpha} + \frac{i}{\alpha} \cdot \frac{i}{\alpha}\right) + \left(\frac{4}{\alpha \cdot \alpha} + 2 \cdot \left(\frac{\beta}{\alpha} \cdot \frac{\beta}{\alpha}\right)\right)\right)\right)\right)}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\log \left(e^{\left(\alpha + \beta\right) \cdot \frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2 \cdot i}}{2 + \left(\left(\alpha + \beta\right) + 2 \cdot i\right)}} \cdot e\right)}{2}\\ \end{array}\]
\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}
\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 -0.9999999999921052:\\
\;\;\;\;\frac{\left(2 \cdot \frac{\beta}{\alpha} + \left(4 \cdot \frac{i}{\alpha} + \frac{2}{\alpha}\right)\right) - \left(6 \cdot \frac{\beta}{\alpha \cdot \alpha} + \left(12 \cdot \frac{i}{\alpha \cdot \alpha} + \left(12 \cdot \left(\frac{\beta}{\alpha} \cdot \frac{i}{\alpha} + \frac{i}{\alpha} \cdot \frac{i}{\alpha}\right) + \left(\frac{4}{\alpha \cdot \alpha} + 2 \cdot \left(\frac{\beta}{\alpha} \cdot \frac{\beta}{\alpha}\right)\right)\right)\right)\right)}{2}\\

\mathbf{else}:\\
\;\;\;\;\frac{\log \left(e^{\left(\alpha + \beta\right) \cdot \frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2 \cdot i}}{2 + \left(\left(\alpha + \beta\right) + 2 \cdot i\right)}} \cdot e\right)}{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
 (if (<=
      (/
       (/ (* (+ alpha beta) (- beta alpha)) (+ (+ alpha beta) (* 2.0 i)))
       (+ 2.0 (+ (+ alpha beta) (* 2.0 i))))
      -0.9999999999921052)
   (/
    (-
     (+ (* 2.0 (/ beta alpha)) (+ (* 4.0 (/ i alpha)) (/ 2.0 alpha)))
     (+
      (* 6.0 (/ beta (* alpha alpha)))
      (+
       (* 12.0 (/ i (* alpha alpha)))
       (+
        (* 12.0 (+ (* (/ beta alpha) (/ i alpha)) (* (/ i alpha) (/ i alpha))))
        (+
         (/ 4.0 (* alpha alpha))
         (* 2.0 (* (/ beta alpha) (/ beta alpha))))))))
    2.0)
   (/
    (log
     (*
      (exp
       (*
        (+ alpha beta)
        (/
         (/ (- beta alpha) (+ (+ alpha beta) (* 2.0 i)))
         (+ 2.0 (+ (+ alpha beta) (* 2.0 i))))))
      E))
    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 tmp;
	if (((((alpha + beta) * (beta - alpha)) / ((alpha + beta) + (2.0 * i))) / (2.0 + ((alpha + beta) + (2.0 * i)))) <= -0.9999999999921052) {
		tmp = (((2.0 * (beta / alpha)) + ((4.0 * (i / alpha)) + (2.0 / alpha))) - ((6.0 * (beta / (alpha * alpha))) + ((12.0 * (i / (alpha * alpha))) + ((12.0 * (((beta / alpha) * (i / alpha)) + ((i / alpha) * (i / alpha)))) + ((4.0 / (alpha * alpha)) + (2.0 * ((beta / alpha) * (beta / alpha)))))))) / 2.0;
	} else {
		tmp = log(exp((alpha + beta) * (((beta - alpha) / ((alpha + beta) + (2.0 * i))) / (2.0 + ((alpha + beta) + (2.0 * i))))) * ((double) M_E)) / 2.0;
	}
	return tmp;
}

Error

Bits error versus alpha

Bits error versus beta

Bits error versus i

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

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)) < -0.9999999999921052

    1. Initial program 62.9

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

    3. Applied add-sqr-sqrt_binary64_146462.8

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

    4. Applied times-frac_binary64_144854.7

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

    5. Simplified54.7

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

    6. Simplified54.7

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

    7. Taylor expanded around inf 13.7

      \[\leadsto \frac{\color{blue}{\left(2 \cdot \frac{\beta}{\alpha} + \left(4 \cdot \frac{i}{\alpha} + 2 \cdot \frac{1}{\alpha}\right)\right) - \left(6 \cdot \frac{\beta}{{\alpha}^{2}} + \left(12 \cdot \frac{i}{{\alpha}^{2}} + \left(12 \cdot \frac{i \cdot \beta}{{\alpha}^{2}} + \left(12 \cdot \frac{{i}^{2}}{{\alpha}^{2}} + \left(4 \cdot \frac{1}{{\alpha}^{2}} + 2 \cdot \frac{{\beta}^{2}}{{\alpha}^{2}}\right)\right)\right)\right)\right)}}{2}\]

    8. Simplified5.6

      \[\leadsto \frac{\color{blue}{\left(2 \cdot \frac{\beta}{\alpha} + \left(4 \cdot \frac{i}{\alpha} + \frac{2}{\alpha}\right)\right) - \left(6 \cdot \frac{\beta}{\alpha \cdot \alpha} + \left(12 \cdot \frac{i}{\alpha \cdot \alpha} + \left(12 \cdot \left(\frac{\beta}{\alpha} \cdot \frac{i}{\alpha} + \frac{i}{\alpha} \cdot \frac{i}{\alpha}\right) + \left(\frac{4}{\alpha \cdot \alpha} + 2 \cdot \left(\frac{\beta}{\alpha} \cdot \frac{\beta}{\alpha}\right)\right)\right)\right)\right)}}{2}\]

    if -0.9999999999921052 < (/.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 13.2

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

    3. Applied *-un-lft-identity_binary64_144213.2

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

    4. Applied *-un-lft-identity_binary64_144213.2

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

    5. Applied times-frac_binary64_14480.2

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

    6. Applied times-frac_binary64_14480.2

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

    7. Simplified0.2

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

    8. Simplified0.2

      \[\leadsto \frac{\left(\beta + \alpha\right) \cdot \color{blue}{\frac{\frac{\beta - \alpha}{2 \cdot i + \left(\beta + \alpha\right)}}{2 + \left(2 \cdot i + \left(\beta + \alpha\right)\right)}} + 1}{2}\]
    9. Using strategy rm

    10. Applied add-log-exp_binary64_14810.2

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

    11. Applied add-log-exp_binary64_14810.2

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

    12. Applied sum-log_binary64_15330.2

      \[\leadsto \frac{\color{blue}{\log \left(e^{\left(\beta + \alpha\right) \cdot \frac{\frac{\beta - \alpha}{2 \cdot i + \left(\beta + \alpha\right)}}{2 + \left(2 \cdot i + \left(\beta + \alpha\right)\right)}} \cdot e^{1}\right)}}{2}\]
  3. Recombined 2 regimes into one program.

  4. Final simplification1.4

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{\left(\alpha + \beta\right) + 2 \cdot i}}{2 + \left(\left(\alpha + \beta\right) + 2 \cdot i\right)} \leq -0.9999999999921052:\\ \;\;\;\;\frac{\left(2 \cdot \frac{\beta}{\alpha} + \left(4 \cdot \frac{i}{\alpha} + \frac{2}{\alpha}\right)\right) - \left(6 \cdot \frac{\beta}{\alpha \cdot \alpha} + \left(12 \cdot \frac{i}{\alpha \cdot \alpha} + \left(12 \cdot \left(\frac{\beta}{\alpha} \cdot \frac{i}{\alpha} + \frac{i}{\alpha} \cdot \frac{i}{\alpha}\right) + \left(\frac{4}{\alpha \cdot \alpha} + 2 \cdot \left(\frac{\beta}{\alpha} \cdot \frac{\beta}{\alpha}\right)\right)\right)\right)\right)}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\log \left(e^{\left(\alpha + \beta\right) \cdot \frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2 \cdot i}}{2 + \left(\left(\alpha + \beta\right) + 2 \cdot i\right)}} \cdot e\right)}{2}\\ \end{array}\]

Reproduce

herbie shell --seed 2021058 
(FPCore (alpha beta i)
  :name "Octave 3.8, jcobi/2"
  :precision binary64
  :pre (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))