\log \left(N + 1\right) - \log N
\begin{array}{l}
\mathbf{if}\;N \le 7771.4619801305835:\\
\;\;\;\;\log \left(1 + \frac{1}{N}\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{N} - \left(\frac{1}{2} - \frac{\frac{1}{3}}{N}\right) \cdot \frac{\frac{1}{N}}{N}\\
\end{array}double f(double N) {
double r2435542 = N;
double r2435543 = 1.0;
double r2435544 = r2435542 + r2435543;
double r2435545 = log(r2435544);
double r2435546 = log(r2435542);
double r2435547 = r2435545 - r2435546;
return r2435547;
}
double f(double N) {
double r2435548 = N;
double r2435549 = 7771.4619801305835;
bool r2435550 = r2435548 <= r2435549;
double r2435551 = 1.0;
double r2435552 = r2435551 / r2435548;
double r2435553 = r2435551 + r2435552;
double r2435554 = log(r2435553);
double r2435555 = 0.5;
double r2435556 = 0.3333333333333333;
double r2435557 = r2435556 / r2435548;
double r2435558 = r2435555 - r2435557;
double r2435559 = r2435552 / r2435548;
double r2435560 = r2435558 * r2435559;
double r2435561 = r2435552 - r2435560;
double r2435562 = r2435550 ? r2435554 : r2435561;
return r2435562;
}



Bits error versus N
Results
if N < 7771.4619801305835Initial program 0.1
rmApplied diff-log0.1
Taylor expanded around 0 0.1
if 7771.4619801305835 < N Initial program 59.5
Taylor expanded around inf 0.0
Simplified0.0
Final simplification0.1
herbie shell --seed 2019168
(FPCore (N)
:name "2log (problem 3.3.6)"
(- (log (+ N 1)) (log N)))