It is well known that the resolution method (for propositional logic) is
complete. However, completeness proofs found in the literature use an argument
by contradiction showing that if a set of clauses is unsatisfiable, then it
must have a resolution refutation. As a consequence, none of these proofs
actually gives an algorithm for producing a resolution refutation from an
unsatisfiable set of clauses. In this note, we give a simple and constructive
proof of the completeness of propositional resolution which consists of an
algorithm together with a proof of its correctness.Comment: 7 pages, submitted to LMC
