A topos-theoretic approach to reference and modality.
Gonzalo E. Reyes · Notre Dame Journal of Formal Logic · 1991
This paper presents an approach to modal logic based on the notion of kind or interpretation of a count noun as a prerequisite for reference.It gives a mathematical formalization of this notion in the context of a locally connected topos δ (thought of as a universe of variable sets) over a topos S (thought of as a universe of constant sets).In this context, modal operators are intrinsically definable and the resulting formal system is described in some detail.*Dedicated to the memory of Isidro Suarez.