\subsection{log}
\label{lablog}
\noindent Name: \textbf{log}\\
\phantom{aaa}natural logarithm.\\[0.2cm]
\noindent Library names:\\
\verb|   sollya_obj_t sollya_lib_log(sollya_obj_t)|\\
\verb|   sollya_obj_t sollya_lib_build_function_log(sollya_obj_t)|\\
\verb|   #define SOLLYA_LOG(x) sollya_lib_build_function_log(x)|\\[0.2cm]
\noindent Description: \begin{itemize}

\item \textbf{log} is the natural logarithm defined as the inverse of the exponential
   function: $\log(y)$ is the unique real number $x$ such that $\exp(x)=y$.

\item It is defined only for $y \in [0; +\infty]$.
\end{itemize}
See also: \textbf{exp} (\ref{labexp}), \textbf{log2} (\ref{lablog2}), \textbf{log10} (\ref{lablog10})
