\[\frac{\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{\left(\alpha + \beta\right) + 2 \cdot i}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2.0} + 1.0}{2.0}\]
Test:
Octave 3.8, jcobi/2
Bits:
128 bits
Bits error versus alpha
Bits error versus beta
Bits error versus i
Time: 53.2 s
Input Error: 11.1
Output Error: 3.3
Log:
Profile: 🕒
\(\begin{cases} \frac{\left(\frac{i}{\alpha + 2.0} \cdot \left(\frac{4 \cdot \alpha}{\alpha + 2.0} + \frac{4.0}{\alpha + 2.0}\right) + \frac{\beta}{\alpha + 2.0} \cdot \left(\frac{2.0}{\alpha + 2.0} + \frac{2 \cdot \alpha}{\alpha + 2.0}\right)\right) - \left(\frac{\alpha}{\alpha + 2.0} - 1.0\right)}{2.0} & \text{when } \frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{\left(\alpha + \beta\right) + 2 \cdot i} \le -2.109379f+16 \\ \frac{\frac{\frac{\alpha + \beta}{{\left(\frac{\left(\alpha + \beta\right) + 2 \cdot i}{\beta - \alpha}\right)}^{1}}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2.0} + 1.0}{2.0} & \text{otherwise} \end{cases}\)

    if (/ (* (+ alpha beta) (- beta alpha)) (+ (+ alpha beta) (* 2 i))) < -2.109379f+16

    1. Started with
      \[\frac{\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{\left(\alpha + \beta\right) + 2 \cdot i}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2.0} + 1.0}{2.0}\]
      30.9
    2. Using strategy rm
      30.9
    3. Applied associate-/l* to get
      \[\frac{\frac{\color{red}{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{\left(\alpha + \beta\right) + 2 \cdot i}}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2.0} + 1.0}{2.0} \leadsto \frac{\frac{\color{blue}{\frac{\alpha + \beta}{\frac{\left(\alpha + \beta\right) + 2 \cdot i}{\beta - \alpha}}}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2.0} + 1.0}{2.0}\]
      25.3
    4. Using strategy rm
      25.3
    5. Applied add-cube-cbrt to get
      \[\frac{\color{red}{\frac{\frac{\alpha + \beta}{\frac{\left(\alpha + \beta\right) + 2 \cdot i}{\beta - \alpha}}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2.0}} + 1.0}{2.0} \leadsto \frac{\color{blue}{{\left(\sqrt[3]{\frac{\frac{\alpha + \beta}{\frac{\left(\alpha + \beta\right) + 2 \cdot i}{\beta - \alpha}}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2.0}}\right)}^3} + 1.0}{2.0}\]
      25.3
    6. Applied taylor to get
      \[\frac{{\left(\sqrt[3]{\frac{\frac{\alpha + \beta}{\frac{\left(\alpha + \beta\right) + 2 \cdot i}{\beta - \alpha}}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2.0}}\right)}^3 + 1.0}{2.0} \leadsto \frac{\left(\left(4.0 \cdot \frac{i}{{\left(2.0 + \alpha\right)}^2} + \left(4 \cdot \frac{\alpha \cdot i}{{\left(2.0 + \alpha\right)}^2} + \left(2.0 \cdot \frac{\beta}{{\left(2.0 + \alpha\right)}^2} + 2 \cdot \frac{\beta \cdot \alpha}{{\left(2.0 + \alpha\right)}^2}\right)\right)\right) - \frac{\alpha}{2.0 + \alpha}\right) + 1.0}{2.0}\]
      28.6
    7. Taylor expanded around 0 to get
      \[\frac{\color{red}{\left(\left(4.0 \cdot \frac{i}{{\left(2.0 + \alpha\right)}^2} + \left(4 \cdot \frac{\alpha \cdot i}{{\left(2.0 + \alpha\right)}^2} + \left(2.0 \cdot \frac{\beta}{{\left(2.0 + \alpha\right)}^2} + 2 \cdot \frac{\beta \cdot \alpha}{{\left(2.0 + \alpha\right)}^2}\right)\right)\right) - \frac{\alpha}{2.0 + \alpha}\right)} + 1.0}{2.0} \leadsto \frac{\color{blue}{\left(\left(4.0 \cdot \frac{i}{{\left(2.0 + \alpha\right)}^2} + \left(4 \cdot \frac{\alpha \cdot i}{{\left(2.0 + \alpha\right)}^2} + \left(2.0 \cdot \frac{\beta}{{\left(2.0 + \alpha\right)}^2} + 2 \cdot \frac{\beta \cdot \alpha}{{\left(2.0 + \alpha\right)}^2}\right)\right)\right) - \frac{\alpha}{2.0 + \alpha}\right)} + 1.0}{2.0}\]
      28.6
    8. Applied simplify to get
      \[\frac{\left(\left(4.0 \cdot \frac{i}{{\left(2.0 + \alpha\right)}^2} + \left(4 \cdot \frac{\alpha \cdot i}{{\left(2.0 + \alpha\right)}^2} + \left(2.0 \cdot \frac{\beta}{{\left(2.0 + \alpha\right)}^2} + 2 \cdot \frac{\beta \cdot \alpha}{{\left(2.0 + \alpha\right)}^2}\right)\right)\right) - \frac{\alpha}{2.0 + \alpha}\right) + 1.0}{2.0} \leadsto \frac{\left(\left(\frac{4 \cdot i}{2.0 + \alpha} \cdot \frac{\alpha}{2.0 + \alpha} + \frac{\frac{i \cdot 4.0}{2.0 + \alpha}}{2.0 + \alpha}\right) + \left(\frac{\beta}{2.0 + \alpha} \cdot \frac{2.0}{2.0 + \alpha} + \frac{2}{2.0 + \alpha} \cdot \frac{\beta \cdot \alpha}{2.0 + \alpha}\right)\right) - \left(\frac{\alpha}{2.0 + \alpha} - 1.0\right)}{2.0}\]
      17.9

    9. Applied final simplification
    10. Applied simplify to get
      \[\color{red}{\frac{\left(\left(\frac{4 \cdot i}{2.0 + \alpha} \cdot \frac{\alpha}{2.0 + \alpha} + \frac{\frac{i \cdot 4.0}{2.0 + \alpha}}{2.0 + \alpha}\right) + \left(\frac{\beta}{2.0 + \alpha} \cdot \frac{2.0}{2.0 + \alpha} + \frac{2}{2.0 + \alpha} \cdot \frac{\beta \cdot \alpha}{2.0 + \alpha}\right)\right) - \left(\frac{\alpha}{2.0 + \alpha} - 1.0\right)}{2.0}} \leadsto \color{blue}{\frac{\left(\frac{i}{\alpha + 2.0} \cdot \left(\frac{4 \cdot \alpha}{\alpha + 2.0} + \frac{4.0}{\alpha + 2.0}\right) + \frac{\beta}{\alpha + 2.0} \cdot \left(\frac{2.0}{\alpha + 2.0} + \frac{2 \cdot \alpha}{\alpha + 2.0}\right)\right) - \left(\frac{\alpha}{\alpha + 2.0} - 1.0\right)}{2.0}}\]
      13.4

    if -2.109379f+16 < (/ (* (+ alpha beta) (- beta alpha)) (+ (+ alpha beta) (* 2 i)))

    1. Started with
      \[\frac{\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{\left(\alpha + \beta\right) + 2 \cdot i}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2.0} + 1.0}{2.0}\]
      7.0
    2. Using strategy rm
      7.0
    3. Applied associate-/l* to get
      \[\frac{\frac{\color{red}{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{\left(\alpha + \beta\right) + 2 \cdot i}}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2.0} + 1.0}{2.0} \leadsto \frac{\frac{\color{blue}{\frac{\alpha + \beta}{\frac{\left(\alpha + \beta\right) + 2 \cdot i}{\beta - \alpha}}}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2.0} + 1.0}{2.0}\]
      1.4
    4. Using strategy rm
      1.4
    5. Applied pow1 to get
      \[\frac{\frac{\frac{\alpha + \beta}{\color{red}{\frac{\left(\alpha + \beta\right) + 2 \cdot i}{\beta - \alpha}}}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2.0} + 1.0}{2.0} \leadsto \frac{\frac{\frac{\alpha + \beta}{\color{blue}{{\left(\frac{\left(\alpha + \beta\right) + 2 \cdot i}{\beta - \alpha}\right)}^{1}}}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2.0} + 1.0}{2.0}\]
      1.2

  1. Removed slow pow expressions

Original test:


(lambda ((alpha default) (beta default) (i default))
  #:name "Octave 3.8, jcobi/2"
  (/ (+ (/ (/ (* (+ alpha beta) (- beta alpha)) (+ (+ alpha beta) (* 2 i))) (+ (+ (+ alpha beta) (* 2 i)) 2.0)) 1.0) 2.0))