
Authors:
Hajnal ANDREKA, Steven GIVANT and Istvan NEMETI
Title:Decision problems for equational theories of relation algebras
Pages:4752
File:bibtex
Abstract ( + )
The foundation of an algebraic theory of binary relations was laid by C. S. Peirce, building on earlier work of Boole and De Morgan. The basic universe of discourse of this theory is a collection of binary relations over some set, and the basic operations on these relations are those of forming unions, complements, relative products (i.e., compositions), and converses (i.e., inverses). There is also a distinguished relation, the identity relation. Other operations and distinguished relations studied by Peirce are definable in terms of the ones just mentioned. Such an algebra of relations is called a set relation algebra.

Authors:
Grzegorz BRYLL and Zofia KOSTRZYCKA
Title:Stoic ``Undemonstrables'' and indirectdeduction theorems
Pages:5360
File:bibtex
Abstract ( + )
Jan Lukasiewicz in the paper From the history of sentential logic, mentions five rules of inference which he calls "undemonstrables" (in Latinindemonstrabilia). In Stoic logic these rules were treated as primitive schemes of inferences requiring no justification. We shall confine our considerations to the complete analysis of only two "undemonstrables", the ones concerning the connectives of implication and negation.

Authors:
John K. SLANEY and Martin W. BUNDER
Title:Classical versions of BCI, BCK and BCIW logics
Pages:6165
File:bibtex
Abstract ( + )
[Abstract]

Authors:
Ildiko SAIN
Title:On finitizing first order logic
Pages:6679
File:bibtex
Abstract ( + )
[Abstract]

Authors:
Jozef WAJSZCZYK
Title:An adequate matrix tor the ``And Next'' calculus of G. H. von Wright
Pages:8092
File:bibtex
Abstract ( + )
In this paper we are going to present an adequate matrix for the "And next" calculus by proving necessary theorems. G. H. von Wright gave an outline of this calculus calling it "Logic of change". Two years later he presented his calculus in an axiomatic form. The "And next" calculus is built on the classical propositional calculus. Its only specific term is a binary logical connective T meant to be interpreted as: "Now ... and next ...".