\log \left(N + 1\right) - \log N
\begin{array}{l}
\mathbf{if}\;N \le 8226.710483527565884287469089031219482422:\\
\;\;\;\;\left(\log \left(\sqrt{N + 1}\right) + \log \left(\frac{\sqrt{1}}{\sqrt{N}}\right)\right) + \log \left(\frac{\sqrt{N + 1}}{\sqrt{N}}\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{N} \cdot \left(\frac{0.3333333333333333148296162562473909929395}{{N}^{2}} + \left(1 - \frac{0.5}{N}\right)\right)\\
\end{array}double f(double N) {
double r59121 = N;
double r59122 = 1.0;
double r59123 = r59121 + r59122;
double r59124 = log(r59123);
double r59125 = log(r59121);
double r59126 = r59124 - r59125;
return r59126;
}
double f(double N) {
double r59127 = N;
double r59128 = 8226.710483527566;
bool r59129 = r59127 <= r59128;
double r59130 = 1.0;
double r59131 = r59127 + r59130;
double r59132 = sqrt(r59131);
double r59133 = log(r59132);
double r59134 = 1.0;
double r59135 = sqrt(r59134);
double r59136 = sqrt(r59127);
double r59137 = r59135 / r59136;
double r59138 = log(r59137);
double r59139 = r59133 + r59138;
double r59140 = r59132 / r59136;
double r59141 = log(r59140);
double r59142 = r59139 + r59141;
double r59143 = r59134 / r59127;
double r59144 = 0.3333333333333333;
double r59145 = 2.0;
double r59146 = pow(r59127, r59145);
double r59147 = r59144 / r59146;
double r59148 = 0.5;
double r59149 = r59148 / r59127;
double r59150 = r59130 - r59149;
double r59151 = r59147 + r59150;
double r59152 = r59143 * r59151;
double r59153 = r59129 ? r59142 : r59152;
return r59153;
}



Bits error versus N
Results
if N < 8226.710483527566Initial program 0.1
rmApplied diff-log0.1
rmApplied *-un-lft-identity0.1
Applied add-sqr-sqrt0.1
Applied times-frac0.1
Applied log-prod0.1
Simplified0.1
rmApplied add-sqr-sqrt0.1
Applied *-un-lft-identity0.1
Applied sqrt-prod0.1
Applied times-frac0.1
Applied log-prod0.1
Applied associate-+r+0.1
if 8226.710483527566 < N Initial program 59.4
Taylor expanded around inf 0.0
Simplified0.0
Final simplification0.1
herbie shell --seed 2019297
(FPCore (N)
:name "2log (problem 3.3.6)"
:precision binary64
(- (log (+ N 1)) (log N)))