\log \left(N + 1\right) - \log N
\begin{array}{l}
\mathbf{if}\;N \le 5705.402280155900371028110384941101074219:\\
\;\;\;\;\left(\log \left(\sqrt{N + 1}\right) - \log \left(\sqrt{N}\right)\right) + \log \left(\sqrt{\frac{N + 1}{N}}\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{0.3333333333333333148296162562473909929395}{N \cdot \left(N \cdot N\right)} + \left(\frac{1}{N} - \frac{0.5}{N \cdot N}\right)\\
\end{array}double f(double N) {
double r4793123 = N;
double r4793124 = 1.0;
double r4793125 = r4793123 + r4793124;
double r4793126 = log(r4793125);
double r4793127 = log(r4793123);
double r4793128 = r4793126 - r4793127;
return r4793128;
}
double f(double N) {
double r4793129 = N;
double r4793130 = 5705.4022801559;
bool r4793131 = r4793129 <= r4793130;
double r4793132 = 1.0;
double r4793133 = r4793129 + r4793132;
double r4793134 = sqrt(r4793133);
double r4793135 = log(r4793134);
double r4793136 = sqrt(r4793129);
double r4793137 = log(r4793136);
double r4793138 = r4793135 - r4793137;
double r4793139 = r4793133 / r4793129;
double r4793140 = sqrt(r4793139);
double r4793141 = log(r4793140);
double r4793142 = r4793138 + r4793141;
double r4793143 = 0.3333333333333333;
double r4793144 = r4793129 * r4793129;
double r4793145 = r4793129 * r4793144;
double r4793146 = r4793143 / r4793145;
double r4793147 = r4793132 / r4793129;
double r4793148 = 0.5;
double r4793149 = r4793148 / r4793144;
double r4793150 = r4793147 - r4793149;
double r4793151 = r4793146 + r4793150;
double r4793152 = r4793131 ? r4793142 : r4793151;
return r4793152;
}



Bits error versus N
Results
if N < 5705.4022801559Initial program 0.1
rmApplied diff-log0.1
rmApplied add-sqr-sqrt0.1
Applied log-prod0.1
rmApplied sqrt-div0.1
Applied log-div0.1
if 5705.4022801559 < N Initial program 59.3
Taylor expanded around inf 0.1
Simplified0.1
Final simplification0.1
herbie shell --seed 2019174
(FPCore (N)
:name "2log (problem 3.3.6)"
(- (log (+ N 1.0)) (log N)))