Nonclassical logics and information processing. International Workshop, Berlin, Germany, November 9-10, 1990. Proceedings (Q1202198)

[The articles of this volume will not be indexed individually.] The volume represents the proceedings of the First All-Berlin Workshop on Nonclassical Logic and Information Processing, held at the Free University of Berlin, 9-10 November, 1990. Since all papers (grouped in four sections) are of high quality, they properly deserve a particular (and equal) interest; we adopt the solution of listing the title and author, accompanied by few words about each paper. Section I: Modal systems. 1) `Algebraic aspects of relational knowledge representation' (\textit{Eva Orlowska}) investigates relation algebra semantics for various applied logics and introduces several classes of modal relation algebras; 2) `A logic of memory' (\textit{Christian Schumacher}) presents conditions for specifying factual memory in precise terms; 3) `Actions with preconditions and postconditions' (\textit{Michael Morreau}) provides axiomatization of a logic for modal action frames with the conditional connective ``\(>\)''. Section II: Logic programming. 1) `Testclasses and closed world assumptions for non-Horn theories' (\textit{Jürgen Gehne}) investigates results related to the following notions: (generalized) \(\Sigma\)-closed world assumption, and \(\Sigma\)- irreducibility of an arbitrary theory (for a given sublattice \(\Sigma\) of first-order sentences); 2) `Reasoning and negative information, II: Hard negation, strong negation and logic programs' (\textit{David Pearce}) propose a criterion by which a negation operator can be said to express explicit falsity, and relates logic programming systems (satisfying this criterion) to constructive logic; 3) `Lindenbaum-algebraic semantics for logic programs' (\textit{Gerd Wagner}) shows how to obtain the Lindenbaum algebra of a logic program. Section III: Nonmonotonic logics. 1) `Conditional logics and cumulative logics' (\textit{André Fuhrmann}) points out to close relationship between familiar conditional logics and a kind of nonmonotonic reasoning based on cumulative inference; 2) `Semantics of nonmonotonic reasoning in logic programming' (\textit{Heinrich Herre}) analyses non-monotonic reasoning for universal theories and logic programs in the framework of inference operations based on model operators. Section IV: Proof theory. 1) `Formulas-as-types for a hierarchy of sublogics of intuitionistic propositional logic' (\textit{Heinrich Wansing}) contains a detailed presentation of W. A. Howard's formulas-as-types notion for constructing fragments of various subsystems of intuitionistic propositional logic; 2) `Cut elimination for logics with definitional reflection' (\textit{Peter Schroeder-Heister}) provides proof-theoretic properties of first-order sequent systems with definitional reflection.