Reconciliation of Approaches to the Semantics of Logics without Distribution

TL;DR

This paper clarifies and completes a relational semantics approach for non-distributive logics, simplifying existing frameworks while preserving their core ideas, thus unifying and advancing the theoretical understanding of such logics.

Contribution

It introduces a simplified relational semantics framework that captures all key results of the RS-frames approach for non-distributive logics, completing Dunn's gaggle theory.

Findings

Simplified semantics framework captures RS-frames results

All main ideas of non-distributive logic semantics are preserved

Unifies and completes Dunn's gaggle theory for non-distributive logics

Abstract

This article contributes in that it clarifies and indeed completes an approach (initiated by Dunn and this author several years ago and again pursued by the present author over the last three years or so) to the relational semantics of logics that may lack distribution (Dunn's non-distributive gaggles). The approach uses sorted frames with an incidence relation on sorts (polarities), equipped with additional sorted relations, but, in the spirit of Occam's razor principle, it drops the extra assumptions made in the generalized Kripke frames approach, initiated by Gehrke, that the frames be separated and reduced (RS-frames). We show in this article that, despite rejecting the additional frame restrictions, all the main ideas and results of the RS-frames approach relating to the semantics of non-distributive logics are captured in this simpler framework. This contributes in unifying the research field, and, in an important sense, it complements and completes Dunn's gaggle theory project for the particular case of logics that may drop distribution.