cleanup: remove dead code
cleanup
fix HTML rendering of sets.
cleanup
unify A,B when A and B are sets should be intersection of A and B.
if given parent which is a lexeme is not supported: throw Exception.
add :constraints key to declarative-sentence.
(over) takes :top as either child
(over) takes one child or two children (i.e. second child arg is optional)
allow (fo) to display keywords
more logging
OFF->ERROR for base logging