Consider Query Subquery Nets for lazy grounding

[jblaszczyk]

Potassco/Gringo and DLV use magic sets technique for grounding. Query-Subquery Nets [1][2] can also be used to find lower & upper bounds and even grounding program more efficiently.

I was wondering if QSQN algorithm could be used for lazy grounding in Alpha?

[1] Cao, S.T. - Methods for Evaluating Queries to Horn Knowledge Bases in First Order Logic [2] Cao, S.T., L.A. Nguyen - Extending Query-Subquery Nets for Deductive Databases under the Well-Founded Semantics