  def _unnumber_chaps_and_secs(lines):
      def _startswith_unnumbered(l):
          UNNUMBERED = {'\\section{Summary',
                        '\\section{Exercise',
                        '\\section{Exercises',
                        '\\section{Discussions',
                        '\\subsection{Summary',
                        '\\subsection{Exercise',
                        '\\subsection{Exercises',
                        '\\subsection{Discussions'}
          for unnum in UNNUMBERED:
 
</s> remove                       '\\subsection{Exercises',
                      '\\subsection{Discussions'}
 </s> add                       '\\subsection{Exercises'} </s> remove     lines = _delete_discussions_title(lines)
 </s> add     #lines = _delete_discussions_title(lines)
                      '\\section{Exercises'
  def _unnumber_chaps_and_secs(lines):
      def _startswith_unnumbered(l):
          UNNUMBERED = {'\\section{Summary',
                        '\\section{Exercise',
                      '\\section{Exercises'
                      '\\section{Exercises'
                        '\\subsection{Summary',
                        '\\subsection{Exercise',
                        '\\subsection{Exercises',
                        '\\subsection{Discussions'}
          for unnum in UNNUMBERED:
keep keep keep keep replace replace keep keep keep keep keep
 re-enable discussion section as numbered 
static/post_latex/main.py