Fixed non-escaped underscore in section headings (document generation should work again now).
Fixed non-escaped underscore in section headings (document generation should
work again now).

MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle