) = 0;     virtual HdLitUid headaggr(Location const &loc, TheoryAtomUid atom) = 0;     virtual HdLitUid headaggr(Location const &loc, AggregateFunction fun, BoundVecUid bounds, HdAggrElemVecUid headaggrelemvec) = 0;     virtual HdLitUid headaggr(Location const &loc, AggregateFunction fun, BoundVecUid bounds, CondLitVecUid headaggrelemvec) = 0;     virtual HdLitUid disjunction(Location const &loc, CondLitVecUid condlitvec) 