Nienhuys-Cheng, S-H.

clause example substitution nement generalization sentence re nement operator operator variable program literal partition number concept problem theorem specialization re nement operators algorithm resolution subsumption nition re nements computation class lemma term partitions proof equivalent occurrence clausal forms clause c subset model clausal subsume block result section element chain stage graph f 2 f function system position order relation dimension specialization problem w.r.t search space arrow language process notice output theory logic transition formula stream shapiro input search term occurrences resolvent property condition article proposition complexity subsumption theorem equivalence order relation output stream implication inductive completeness