Consistent posets

TL;DR

This paper introduces consistent posets, a class of bounded posets with an antitone involution, and explores their algebraic representations, properties, and applications to non-classical logic semantics.

Contribution

It defines consistent posets, links them to commutative meet-directoids, and shows their use as algebraic semantics for certain non-classical logics.

Findings

Consistent posets can be represented by commutative meet-directoids with an antitone involution.

Finite consistent posets can be transformed into residuated structures.

The Dedekind-MacNeille completion of a consistent poset is a consistent lattice.

Abstract

We introduce so-called consistent posets which are bounded posets with an antitone involution ' where the lower cones of x,x' and of y,y' coincide provided x,y are different form 0,1 and, moreover, if x,y are different form 0 then their lower cone is different form 0, too. We show that these posets can be represented by means of commutative meet-directoids with an antitone involution satisfying certain identities and implications. In the case of a finite distributive or strongly modular consistent poset, this poset can be converted into a residuated structure and hence it can serve as an algebraic semantics of a certain non-classical logic with unsharp conjunction and implication. Finally we show that the Dedekind-MacNeille completion of a consistent poset is a consistent lattice, i.e. a bounded lattice with an antitone involution satisfying the above mentioned properties.