This paper studies the relationship between Argumentation Logic, a recently defined logic based on the study of argumentation in AI, and classical Propositional Logic. In particular, it shows that AL and PL are logically equivalent in that they have the same entailment relation from any given classically consistent theory. This equivalence follows from a correspondence between the non-acceptability of sentences in AL and Natural Deduction proofs of the complement of these sentences. The proof of this equivalence uses a restricted form (...) of ND proofs, where hypotheses in the application of the Reductio of Absurdum inference rule are required to be “relevant” to the absurdity derived in the rule. The paper also discusses how the argumentative re-interpretation of PL could help control the application of ex-falso quodlibet in the presence of inconsistencies. (shrink)

Alan Robinson This set of essays pays tribute to Bob Kowalski on his 60th birthday, an anniversary which gives his friends and colleagues an excuse to celebrate his career as an original thinker, a charismatic communicator, and a forceful intellectual leader. The logic programming community hereby and herein conveys its respect and thanks to him for his pivotal role in creating and fostering the conceptual paradigm which is its raison d’Œtre. The diversity of interests covered here reflects the variety of (...) Bob’s concerns. Read on. It is an intellectual feast. Before you begin, permit me to send him a brief personal, but public, message: Bob, how right you were, and how wrong I was. I should explain. When Bob arrived in Edinburgh in 1967 resolution was as yet fairly new, having taken several years to become at all widely known. Research groups to investigate various aspects of resolution sprang up at several institutions, the one organized by Bernard Meltzer at Edinburgh University being among the first. For the half-dozen years that Bob was a leading member of Bernard’s group, I was a frequent visitor to it, and I saw a lot of him. We had many discussions about logic, computation, and language. (shrink)

O.T. 463 sq.BRUHN followed Zielinski in adopting είδε from F, and used the variant together with others as establishing the value of Fas an independent source. We have already seen reason for refusing to attach much importance to the authority of this MS. , but it should be observed that both readings are recognized by Σ, and the question between επε and είδε must be settled on its merits. Γ itself has πε written over the last syllable of είδε, and (...) Zenodotus read επ for εδ in Hom. O 207. Zielinski thinks that Eur. Andr. 998 τελουμένων δ Δελς εσεται πέτρα is an echo of this passage, but the inference is by no means certain. It may be that the original text of Trin points to the true solution, that πε fell out by haplography, and the isolated ε became εσε or δε. (shrink)