Document hexversion (incompletely explained) and version_info (easily
explained).
diff --git a/Doc/lib/libsys.tex b/Doc/lib/libsys.tex
index a92201c..1beb53c 100644
--- a/Doc/lib/libsys.tex
+++ b/Doc/lib/libsys.tex
@@ -138,6 +138,28 @@
(temporary) reference as an argument to \function{getrefcount()}.
\end{funcdesc}
+\begin{datadesc}{hexversion}
+The version number encoded as a single integer. This is guaranteed to
+increase with each version, including proper support for
+non-production releases. For example, to test that the Python
+interpreter is at least version 1.5.2, use:
+
+\begin{verbatim}
+if sys.hexversion >= 0x010502F0:
+ # use some advanced feature
+ ...
+else:
+ # use an alternative implementation or warn the user
+ ...
+\end{verbatim}
+
+This is called \samp{hexversion} since it only really looks meaningful
+when viewed as the result of passing it to the built-in
+\function{hex()} function. The \code{version_info} value may be used
+for a more human-friendly encoding of the same information.
+\versionadded{1.5.2}
+\end{datadesc}
+
\begin{datadesc}{last_type}
\dataline{last_value}
\dataline{last_traceback}
@@ -304,6 +326,16 @@
\end{verbatim}
\end{datadesc}
+\begin{datadesc}{version_info}
+A tuple containing the four components of the version number:
+\var{major}, \var{minor}, \var{micro} as integers, and
+\var{releaselevel} as a string. The \var{releaselevel} value will be
+an empty string for a final release. The \code{version_info} value
+corresponding to the \code{version} string shown above is
+\code{(1, 5, 2, '')}.
+\versionadded{1.6}
+\end{datadesc}
+
\begin{datadesc}{winver}
The version number used to form registry keys on Windows platforms.
This is stored as string resource 1000 in the Python DLL. The value