fix sectioning: cannot skip section levels
diff --git a/Doc/lib/libast.tex b/Doc/lib/libast.tex
index b3c3148..b2956ae 100644
--- a/Doc/lib/libast.tex
+++ b/Doc/lib/libast.tex
@@ -47,11 +47,11 @@
can have zero-or-more values (marked with an asterisk), the
values are represented as Python lists.
-\subsection{Abstract Grammar}
+\section{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
+\verbatiminput{../../Parser/Python.asdl}