As is normally the case in CLP, deductive search is used alongside constraint resolution.
under such assumptions, our principles can be converted to: with an implementation of type-antecedent constraints and an implementation of whenfs/2 (Section 3.3), which delays the goal in its second argument until v is subsumed by (one of) the most general satisfier(s) of description α, all that remains is a method for finding the trigger, the most efficient type antecedent to use, i.e., the most general one that will not violate soundness.