Nonstandard Consequence Operators

Abstract

In this paper, we investigate the algebras of consequence operators and finite consequence operators on a fixed language. Significant new collections of consequence operators are defined and shown to be complete and distributive sublattices. Further, the collection of consequence operators is shown to be almost atomic. Other lattice theoretic properties are investigated and useful chain properties are obtained. In the last section, natural languages, and associated consequence operators, are encoded and embedded into a nonstandard structure. The entire basic theory of nonstandard consequence operators is developed in this last section.