Graph-Based Logic and Sketches II: Finite-Product Categories and Equational Logic (Preliminary Report)

It is shown that the proof theory for sketches and forms provided in Part I of this paper (see this http URL) is strong enough to produce all the theorems of the entailment system for multisorted equational logic provided in Goguen and Meseguer's article ``Completeness of many-sorted equational logic'' (Technical Report CSL-135, SRI International Computer Science Laboratory, 333 Ravenswood Ave., Menlo Park, CA 94025, USA, 1982).