Add generation of the version.
diff --git a/Doc/lib/libast.tex b/Doc/lib/libast.tex
index 9fdd4fb..ca798c9 100644
--- a/Doc/lib/libast.tex
+++ b/Doc/lib/libast.tex
@@ -4,6 +4,8 @@
\sectionauthor{Martin v. L\"owis}{martin@v.loewis.de}
+\versionadded{2.5}
+
The \code{_ast} module helps Python applications to process
trees of the Python abstract syntax grammar. The Python compiler
currently provides read-only access to such trees, meaning that
@@ -41,6 +43,9 @@
\subsection{Abstract Grammar}
+The module defines a string constant \code{__version__} which
+is the decimal subversion revision number of the file shown below.
+
The abstract grammar is currently defined as follows:
\verbatiminput{../../Parser/Python.asdl}
\ No newline at end of file