o Changed part of the of partial function axiomatization to reflect that overriding indeed favors the rhs operator
o Fixed a problem where, when there are many declaration of type (Maybe a) in Z3, for different a's, Nothing has an ambiguous type. It has to be cast in the right type. Literate-UnitB therefore always casts Nothing.
o some POs now fail after flushing out the axiomatization errors. They remain to be investigated.
the some proof obligation tests that were broken