A demand-driven narrowing calculus with overlapping definitional trees
Rafael del Vado Vírseda · 2003
We propose a demand-driven conditional narrowing calculus in which a variant of definitional trees [2] is used to efficiently control the narrowing strategy. This calculus is sound and strongly complete w.r.t. Constructor-based ReWriting Logic (CRWL) semantics [7] for a wide class of constructor-based conditional term rewriting systems. The calculus mantains the optimality properties of the needed narrowing strategy [5]. Moreover, the treatment of strict equality as a primitive rather than a defined function symbol, leads to an improved behaviour w.r.t. needed narrowing.