Vector spaces as Kripke frames

TL;DR

This paper extends vector space semantics to the general Lambek calculus using algebraic structures called -algebras, linking them to Kripke frames and modal substructural logics.

Contribution

It introduces a novel vector space semantics for the Lambek calculus based on -algebras, connecting algebraic and Kripke semantics for substructural logics.

Findings

-algebras serve as Kripke frames for vector space semantics.

Established a systematic link between vector space semantics and Routley-Meyer semantics.

Extended the semantics from associative to general Lambek calculus.

Abstract

In recent years, the compositional distributional approach in computational linguistics has opened the way for an integration of the \emph{lexical} aspects of meaning into Lambek's type-logical grammar program. This approach is based on the observation that a sound semantics for the associative, commutative and unital Lambek calculus can be based on vector spaces by interpreting fusion as the tensor product of vector spaces. In this paper, we build on this observation and extend it to a `vector space semantics' for the \emph{general} Lambek calculus, based on \emph{algebras over a field} $\mathbb{K}$ (or $\mathbb{K}$-algebras), i.e. vector spaces endowed with a bilinear binary product. Such structures are well known in algebraic geometry and algebraic topology, since they are important instances of Lie algebras and Hopf algebras. Applying results and insights from duality and representation theory for the algebraic semantics of nonclassical logics, we regard $\mathbb{K}$-algebras as `Kripke frames' the complex algebras of which are complete residuated lattices. This perspective makes it possible to establish a systematic connection between vector space semantics and the standard Routley-Meyer semantics of (modal) substructural logics.