Average Error: 32.7 → 24.6
Time: 47.1s
Precision: 64
Internal Precision: 1408
\[{\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}\]
\[\begin{array}{l} \mathbf{if}\;n \le -2.5497319076435205 \cdot 10^{+26}:\\ \;\;\;\;\left(\frac{\frac{1}{n}}{x} + \left(-1 + 1\right)\right) - \log \left(e^{\frac{\frac{\frac{1}{2}}{x}}{x \cdot n}}\right)\\ \mathbf{if}\;n \le 48879.08771223247:\\ \;\;\;\;\log \left(e^{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)}} \cdot \log \left(e^{e^{-{x}^{\left(\frac{1}{n}\right)}}}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\frac{\frac{1}{n}}{x} + \left(-1 + 1\right)\right) - \log \left(e^{\frac{\frac{\frac{1}{2}}{x}}{x \cdot n}}\right)\\ \end{array}\]

Error

Bits error versus x

Bits error versus n

Derivation

  1. Split input into 2 regimes
  2. if n < -2.5497319076435205e+26 or 48879.08771223247 < n

    1. Initial program 44.7

      \[{\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}\]
    2. Using strategy rm
    3. Applied add-log-exp44.7

      \[\leadsto {\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - \color{blue}{\log \left(e^{{x}^{\left(\frac{1}{n}\right)}}\right)}\]
    4. Applied add-log-exp44.7

      \[\leadsto \color{blue}{\log \left(e^{{\left(x + 1\right)}^{\left(\frac{1}{n}\right)}}\right)} - \log \left(e^{{x}^{\left(\frac{1}{n}\right)}}\right)\]
    5. Applied diff-log44.7

      \[\leadsto \color{blue}{\log \left(\frac{e^{{\left(x + 1\right)}^{\left(\frac{1}{n}\right)}}}{e^{{x}^{\left(\frac{1}{n}\right)}}}\right)}\]
    6. Applied simplify44.7

      \[\leadsto \log \color{blue}{\left(e^{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}\right)}\]
    7. Using strategy rm
    8. Applied sub-neg44.7

      \[\leadsto \log \left(e^{\color{blue}{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} + \left(-{x}^{\left(\frac{1}{n}\right)}\right)}}\right)\]
    9. Applied exp-sum44.7

      \[\leadsto \log \color{blue}{\left(e^{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)}} \cdot e^{-{x}^{\left(\frac{1}{n}\right)}}\right)}\]
    10. Taylor expanded around inf 33.3

      \[\leadsto \color{blue}{\left(\log \left(e^{-1} \cdot e\right) + \frac{1}{n \cdot x}\right) - \frac{1}{2} \cdot \frac{1}{n \cdot {x}^{2}}}\]
    11. Applied simplify32.6

      \[\leadsto \color{blue}{\left(\frac{\frac{1}{n}}{x} + \left(-1 + 1\right)\right) - \frac{\frac{\frac{1}{2}}{x}}{x \cdot n}}\]
    12. Using strategy rm
    13. Applied add-log-exp32.6

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

    if -2.5497319076435205e+26 < n < 48879.08771223247

    1. Initial program 6.5

      \[{\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}\]
    2. Using strategy rm
    3. Applied add-log-exp6.9

      \[\leadsto {\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - \color{blue}{\log \left(e^{{x}^{\left(\frac{1}{n}\right)}}\right)}\]
    4. Applied add-log-exp6.9

      \[\leadsto \color{blue}{\log \left(e^{{\left(x + 1\right)}^{\left(\frac{1}{n}\right)}}\right)} - \log \left(e^{{x}^{\left(\frac{1}{n}\right)}}\right)\]
    5. Applied diff-log6.9

      \[\leadsto \color{blue}{\log \left(\frac{e^{{\left(x + 1\right)}^{\left(\frac{1}{n}\right)}}}{e^{{x}^{\left(\frac{1}{n}\right)}}}\right)}\]
    6. Applied simplify6.8

      \[\leadsto \log \color{blue}{\left(e^{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}\right)}\]
    7. Using strategy rm
    8. Applied sub-neg6.8

      \[\leadsto \log \left(e^{\color{blue}{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} + \left(-{x}^{\left(\frac{1}{n}\right)}\right)}}\right)\]
    9. Applied exp-sum6.9

      \[\leadsto \log \color{blue}{\left(e^{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)}} \cdot e^{-{x}^{\left(\frac{1}{n}\right)}}\right)}\]
    10. Using strategy rm
    11. Applied add-log-exp7.0

      \[\leadsto \log \left(e^{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)}} \cdot \color{blue}{\log \left(e^{e^{-{x}^{\left(\frac{1}{n}\right)}}}\right)}\right)\]
  3. Recombined 2 regimes into one program.
  4. Removed slow pow expressions.

Runtime

Time bar (total: 47.1s)Debug logProfile

herbie shell --seed '#(1063313015 2771194459 1594909340 1344785158 2223560818 546365448)' 
(FPCore (x n)
  :name "2nthrt (problem 3.4.6)"
  (- (pow (+ x 1) (/ 1 n)) (pow x (/ 1 n))))