I'm running 'Sage Version 6.5.rc0, Release Date: 2015-01-29' and when I display the help for sage.structure.indexed_generators.IndexedGenerators I get some weird formatting error. It's coming from line 103 of the file \$SAGE_ROOT/local/lib/python2.7/site-packages/sage/structure/indexed_generators.py where a \left is displayed as <=ft. It seems that \le in \left gets replaced by <=.