Diagram(
  Terminal('MODULE'),
  NonTerminal('module_name'),
  ZeroOrMore(
    Choice(0,
      Sequence(Terminal('HEADER'), NonTerminal('extension')),
      Terminal('NOHEADER'),
      Sequence(Terminal('SOURCE'), NonTerminal('extension')),
      Terminal('INLINE'),
      Sequence(Terminal('NOSOURCE'), Comment('deprecated'))))
)