Add markup for base parameter
diff --git a/Doc/lib/libmath.tex b/Doc/lib/libmath.tex
index 1dc4365..0571b18 100644
--- a/Doc/lib/libmath.tex
+++ b/Doc/lib/libmath.tex
@@ -87,8 +87,8 @@
\end{funcdesc}
\begin{funcdesc}{log}{x\optional{, base}}
-Returns the logarithm of \var{x} to the given base.
-If the base is not specified, returns the natural logarithm of \var{x}.
+Returns the logarithm of \var{x} to the given \var{base}.
+If the \var{base} is not specified, returns the natural logarithm of \var{x}.
\versionchanged[\var{base} argument added]{2.3}
\end{funcdesc}