code: Rule Aeolian() {
  		return Sequence(IgnoreCase("aeo"),
  			Optional(Sequence(IgnoreCase("l"),
  				Optional(Sequence(IgnoreCase("i"),
  					Optional(Sequence(IgnoreCase("a"),
  						Optional(IgnoreCase("n"))
  					))
  				))
  			))
  		).label(Aeolian).suppressSubnodes();
  	}
docs: =minor
  
  aeolian ::= "aeo" ["l" ["i" ["a" ["n"]]]]