A Categorical Integration of Quantifiers:A Higher Category Theoretic Perspective
Barreto Joaquim Reizi
TL;DR
This work develops a higher-categorical framework to integrate quantifiers with other logical connectives, explicitly encoding coherence data via 2-morphisms and pseudo-limits. By lifting classical adjunctions to 2-adjunctions and employing pseudo-limits, the authors construct a global quantifier category that coherently unifies local fiberwise quantifiers across contexts, with strictification to a strict 2-category to simplify proofs. They provide detailed constructions, diagrams, and concrete examples in Set, presheaf categories, LCCC, and topoi, illustrating how existential and universal quantifiers arise as left and right adjoints to reindexing, respectively. The framework resolves substitution-binding ambiguities in dependent type theory and connects internal logic across various categorical settings, yielding robust model integration and clearer semantic guidance. The approach promises broader applicability to dependent type theories, topos theory, and higher-type logics, with potential extensions to additional logical connectives and computational implementations. Overall, the paper offers a principled, coherence-aware semantic foundation that bridges classical adjunction theory and higher-dimensional categorical logic for quantifiers.
Abstract
We propose a new framework for integrating quantifiers with other logical connectives in a higher-categorical setting. Our method systematically incorporates key coherence conditions-including those akin to the Beck-Chevalley property-and exploits the potential of 2-adjunctions and pseudo-limits. In particular, Theorem 2.1 and Lemma 3.4 establish the central results, showing how the usual view of quantifiers as adjoint functors lifts naturally into a bicategorical context, while Theorem 4.2 and Lemma 4.3 illustrate how this perspective extends to dependent type theories. By making explicit the interplay between substitution and variable binding, we resolve the limitations of conventional approaches and ensure coherence up to canonical isomorphisms. Detailed constructions, coherence diagrams, and a unified schematic overview further highlight the theoretical advantages of our approach, leading to simpler proofs and more robust model integration in categorical logic.
