Expand not-equal for SMT-LIB 2 compatibility
Expand not-equal for SMT-LIB 2 compatibility

agacek/jkind,backesj/jkind,lgwagner/jkind,andrewkatis/jkind-1,backesj/jkind,agacek/jkind,andrewkatis/jkind-1,lgwagner/jkind