Average Error: 29.5 → 0.0
Time: 18.3s
Precision: 64
\[\log \left(N + 1\right) - \log N\]
\[\begin{array}{l} \mathbf{if}\;N \le 7265.781170340218:\\ \;\;\;\;\frac{1}{2} \cdot \log \left(\frac{N + 1}{N}\right) + \log \left(\sqrt{e^{\log \left(\frac{N + 1}{N}\right)}}\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\frac{1}{N} + \frac{\frac{-1}{2}}{N \cdot N}\right) + \frac{\frac{\frac{1}{3}}{N \cdot N}}{N}\\ \end{array}\]
double f(double N) {
        double r2374101 = N;
        double r2374102 = 1.0;
        double r2374103 = r2374101 + r2374102;
        double r2374104 = log(r2374103);
        double r2374105 = log(r2374101);
        double r2374106 = r2374104 - r2374105;
        return r2374106;
}

double f(double N) {
        double r2374107 = N;
        double r2374108 = 7265.781170340218;
        bool r2374109 = r2374107 <= r2374108;
        double r2374110 = 0.5;
        double r2374111 = 1.0;
        double r2374112 = r2374107 + r2374111;
        double r2374113 = r2374112 / r2374107;
        double r2374114 = log(r2374113);
        double r2374115 = r2374110 * r2374114;
        double r2374116 = exp(r2374114);
        double r2374117 = sqrt(r2374116);
        double r2374118 = log(r2374117);
        double r2374119 = r2374115 + r2374118;
        double r2374120 = r2374111 / r2374107;
        double r2374121 = -0.5;
        double r2374122 = r2374107 * r2374107;
        double r2374123 = r2374121 / r2374122;
        double r2374124 = r2374120 + r2374123;
        double r2374125 = 0.3333333333333333;
        double r2374126 = r2374125 / r2374122;
        double r2374127 = r2374126 / r2374107;
        double r2374128 = r2374124 + r2374127;
        double r2374129 = r2374109 ? r2374119 : r2374128;
        return r2374129;
}

\log \left(N + 1\right) - \log N
\begin{array}{l}
\mathbf{if}\;N \le 7265.781170340218:\\
\;\;\;\;\frac{1}{2} \cdot \log \left(\frac{N + 1}{N}\right) + \log \left(\sqrt{e^{\log \left(\frac{N + 1}{N}\right)}}\right)\\

\mathbf{else}:\\
\;\;\;\;\left(\frac{1}{N} + \frac{\frac{-1}{2}}{N \cdot N}\right) + \frac{\frac{\frac{1}{3}}{N \cdot N}}{N}\\

\end{array}

Error

Bits error versus N

Derivation

  1. Split input into 2 regimes
  2. if N < 7265.781170340218

    1. Initial program 0.1

      \[\log \left(N + 1\right) - \log N\]
    2. Using strategy rm
    3. Applied diff-log0.1

      \[\leadsto \color{blue}{\log \left(\frac{N + 1}{N}\right)}\]
    4. Using strategy rm
    5. Applied add-sqr-sqrt0.1

      \[\leadsto \log \color{blue}{\left(\sqrt{\frac{N + 1}{N}} \cdot \sqrt{\frac{N + 1}{N}}\right)}\]
    6. Applied log-prod0.1

      \[\leadsto \color{blue}{\log \left(\sqrt{\frac{N + 1}{N}}\right) + \log \left(\sqrt{\frac{N + 1}{N}}\right)}\]
    7. Using strategy rm
    8. Applied pow10.1

      \[\leadsto \log \left(\sqrt{\color{blue}{{\left(\frac{N + 1}{N}\right)}^{1}}}\right) + \log \left(\sqrt{\frac{N + 1}{N}}\right)\]
    9. Applied sqrt-pow10.1

      \[\leadsto \log \color{blue}{\left({\left(\frac{N + 1}{N}\right)}^{\left(\frac{1}{2}\right)}\right)} + \log \left(\sqrt{\frac{N + 1}{N}}\right)\]
    10. Applied log-pow0.1

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \log \left(\frac{N + 1}{N}\right)} + \log \left(\sqrt{\frac{N + 1}{N}}\right)\]
    11. Simplified0.1

      \[\leadsto \color{blue}{\frac{1}{2}} \cdot \log \left(\frac{N + 1}{N}\right) + \log \left(\sqrt{\frac{N + 1}{N}}\right)\]
    12. Using strategy rm
    13. Applied add-exp-log0.1

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

    if 7265.781170340218 < N

    1. Initial program 59.5

      \[\log \left(N + 1\right) - \log N\]
    2. Taylor expanded around -inf 0.0

      \[\leadsto \color{blue}{\left(\frac{1}{3} \cdot \frac{1}{{N}^{3}} + \frac{1}{N}\right) - \frac{1}{2} \cdot \frac{1}{{N}^{2}}}\]
    3. Simplified0.0

      \[\leadsto \color{blue}{\left(\frac{1}{N} + \frac{\frac{-1}{2}}{N \cdot N}\right) + \frac{\frac{\frac{1}{3}}{N \cdot N}}{N}}\]
  3. Recombined 2 regimes into one program.
  4. Final simplification0.0

    \[\leadsto \begin{array}{l} \mathbf{if}\;N \le 7265.781170340218:\\ \;\;\;\;\frac{1}{2} \cdot \log \left(\frac{N + 1}{N}\right) + \log \left(\sqrt{e^{\log \left(\frac{N + 1}{N}\right)}}\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\frac{1}{N} + \frac{\frac{-1}{2}}{N \cdot N}\right) + \frac{\frac{\frac{1}{3}}{N \cdot N}}{N}\\ \end{array}\]

Reproduce

herbie shell --seed 2019102 
(FPCore (N)
  :name "2log (problem 3.3.6)"
  (- (log (+ N 1)) (log N)))