Average Error: 42.4 → 9.5
Time: 2.4m
Precision: 64
Internal Precision: 1408
\[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}}\]
↓
\[\begin{array}{l} \mathbf{if}\;t \le -1.873856920624348 \cdot 10^{+138}:\\ \;\;\;\;\frac{t \cdot \sqrt{2}}{(\left(\frac{1}{x \cdot x}\right) \cdot \left(\frac{t}{\sqrt{2}}\right) + \left(\left(-t\right) \cdot \sqrt{2}\right))_* - \frac{\frac{2}{x}}{\sqrt{2}} \cdot \left(\frac{t}{x} + t\right)}\\ \mathbf{if}\;t \le 1.662323320309215 \cdot 10^{-243}:\\ \;\;\;\;\frac{t \cdot \sqrt{2}}{\sqrt{\sqrt{(2 \cdot \left((\left(\frac{\ell}{x}\right) \cdot \ell + \left(t \cdot t\right))_*\right) + \left(\frac{4}{x} \cdot \left(t \cdot t\right)\right))_*}} \cdot \sqrt{\sqrt{(2 \cdot \left((\left(\frac{\ell}{x}\right) \cdot \ell + \left(t \cdot t\right))_*\right) + \left(\frac{4}{x} \cdot \left(t \cdot t\right)\right))_*}}}\\ \mathbf{if}\;t \le 2.3538919283163556 \cdot 10^{-162}:\\ \;\;\;\;\frac{t \cdot \sqrt{2}}{(\left(\frac{2}{\sqrt{2}}\right) \cdot \left(\frac{\frac{t}{x}}{x} + \frac{t}{x}\right) + \left((\left(\frac{-1}{\sqrt{2}}\right) \cdot \left(\frac{\frac{t}{x}}{x}\right) + \left(t \cdot \sqrt{2}\right))_*\right))_*}\\ \mathbf{if}\;t \le 2.460625186115655 \cdot 10^{+81}:\\ \;\;\;\;\frac{t \cdot \sqrt{2}}{\sqrt{\sqrt{(2 \cdot \left((\left(\frac{\ell}{x}\right) \cdot \ell + \left(t \cdot t\right))_*\right) + \left(\frac{4}{x} \cdot \left(t \cdot t\right)\right))_*}} \cdot \sqrt{\sqrt{(2 \cdot \left((\left(\frac{\ell}{x}\right) \cdot \ell + \left(t \cdot t\right))_*\right) + \left(\frac{4}{x} \cdot \left(t \cdot t\right)\right))_*}}}\\ \mathbf{else}:\\ \;\;\;\;\frac{t \cdot \sqrt{2}}{(\left(\frac{2}{\sqrt{2}}\right) \cdot \left(\frac{\frac{t}{x}}{x} + \frac{t}{x}\right) + \left((\left(\frac{-1}{\sqrt{2}}\right) \cdot \left(\frac{\frac{t}{x}}{x}\right) + \left(t \cdot \sqrt{2}\right))_*\right))_*}\\ \end{array}\]

Error

Bits error versus x

Bits error versus l

Bits error versus t

Derivation

  1. Split input into 3 regimes

  2. if t < -1.873856920624348e+138

    1. Initial program 58.5

      \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}}\]

    2. Taylor expanded around -inf 2.1

      \[\leadsto \frac{\sqrt{2} \cdot t}{\color{blue}{2 \cdot \frac{t}{{\left(\sqrt{2}\right)}^{3} \cdot {x}^{2}} - \left(t \cdot \sqrt{2} + \left(2 \cdot \frac{t}{\sqrt{2} \cdot x} + 2 \cdot \frac{t}{\sqrt{2} \cdot {x}^{2}}\right)\right)}}\]

    3. Applied simplify2.1

      \[\leadsto \color{blue}{\frac{t \cdot \sqrt{2}}{(\left(\frac{1}{x \cdot x}\right) \cdot \left(\frac{t}{\sqrt{2}}\right) + \left(\left(-t\right) \cdot \sqrt{2}\right))_* - \frac{\frac{2}{x}}{\sqrt{2}} \cdot \left(\frac{t}{x} + t\right)}}\]

    if -1.873856920624348e+138 < t < 1.662323320309215e-243 or 2.3538919283163556e-162 < t < 2.460625186115655e+81

    1. Initial program 34.1

      \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}}\]

    2. Taylor expanded around inf 16.0

      \[\leadsto \frac{\sqrt{2} \cdot t}{\sqrt{\color{blue}{2 \cdot {t}^{2} + \left(2 \cdot \frac{{\ell}^{2}}{x} + 4 \cdot \frac{{t}^{2}}{x}\right)}}}\]

    3. Applied simplify11.5

      \[\leadsto \color{blue}{\frac{t \cdot \sqrt{2}}{\sqrt{(2 \cdot \left((\left(\frac{\ell}{x}\right) \cdot \ell + \left(t \cdot t\right))_*\right) + \left(\frac{4}{x} \cdot \left(t \cdot t\right)\right))_*}}}\]
    4. Using strategy rm

    5. Applied add-sqr-sqrt11.5

      \[\leadsto \frac{t \cdot \sqrt{2}}{\sqrt{\color{blue}{\sqrt{(2 \cdot \left((\left(\frac{\ell}{x}\right) \cdot \ell + \left(t \cdot t\right))_*\right) + \left(\frac{4}{x} \cdot \left(t \cdot t\right)\right))_*} \cdot \sqrt{(2 \cdot \left((\left(\frac{\ell}{x}\right) \cdot \ell + \left(t \cdot t\right))_*\right) + \left(\frac{4}{x} \cdot \left(t \cdot t\right)\right))_*}}}}\]

    6. Applied sqrt-prod11.6

      \[\leadsto \frac{t \cdot \sqrt{2}}{\color{blue}{\sqrt{\sqrt{(2 \cdot \left((\left(\frac{\ell}{x}\right) \cdot \ell + \left(t \cdot t\right))_*\right) + \left(\frac{4}{x} \cdot \left(t \cdot t\right)\right))_*}} \cdot \sqrt{\sqrt{(2 \cdot \left((\left(\frac{\ell}{x}\right) \cdot \ell + \left(t \cdot t\right))_*\right) + \left(\frac{4}{x} \cdot \left(t \cdot t\right)\right))_*}}}}\]

    if 1.662323320309215e-243 < t < 2.3538919283163556e-162 or 2.460625186115655e+81 < t

    1. Initial program 50.2

      \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}}\]

    2. Taylor expanded around inf 9.5

      \[\leadsto \frac{\sqrt{2} \cdot t}{\color{blue}{\left(t \cdot \sqrt{2} + \left(2 \cdot \frac{t}{\sqrt{2} \cdot x} + 2 \cdot \frac{t}{\sqrt{2} \cdot {x}^{2}}\right)\right) - 2 \cdot \frac{t}{{\left(\sqrt{2}\right)}^{3} \cdot {x}^{2}}}}\]

    3. Applied simplify9.5

      \[\leadsto \color{blue}{\frac{t \cdot \sqrt{2}}{(\left(\frac{2}{\sqrt{2}}\right) \cdot \left(\frac{\frac{t}{x}}{x} + \frac{t}{x}\right) + \left((\left(\frac{-1}{\sqrt{2}}\right) \cdot \left(\frac{\frac{t}{x}}{x}\right) + \left(t \cdot \sqrt{2}\right))_*\right))_*}}\]
  3. Recombined 3 regimes into one program.

Runtime

Time bar (total: 2.4m)Debug logProfile

herbie shell --seed '#(1070864556 424010669 783715395 1203517814 4070606583 4107618214)' +o rules:numerics
(FPCore (x l t)
  :name "Toniolo and Linder, Equation (7)"
  (/ (* (sqrt 2) t) (sqrt (- (* (/ (+ x 1) (- x 1)) (+ (* l l) (* 2 (* t t)))) (* l l)))))