PP-2017-03: Tarski's theorem on intuitionistic logic, for polyhedra.

PP-2017-03: Bezhanishvili, Nick and Marra, Vincenzo and McNeill, Daniel and Pedrini, Andrea (2017) Tarski's theorem on intuitionistic logic, for polyhedra. [Pre-print]


Download (379kB) | Preview


In 1938, Tarski proved that a formula is not intuitionistically valid if, and only if, it has a counter-model in the Heyting algebra of open sets of some topological space. In fact, Tarski showed that any Euclidean space R^n with n > 1 suffices, as does e.g. the Cantor space. In particular, intuitionistic logic cannot detect topological dimension in the frame of all open sets of a Euclidean space. By contrast, we consider the lattice of open subpolyhedra of a given compact polyhedron P of R^n, prove that it is a locally finite Heyting subalgebra of the (non-locally-finite) algebra of all open sets of R^n, and show that intuitionistic logic is able to capture the topological dimension of P through the bounded-depth axiom schemata. Further, we show that intuitionistic logic is precisely the logic of formulas valid in all Heyting algebras arising from polyhedra in this manner. Thus, our main theorem reconciles through polyhedral geometry two classical results: topological completeness in the style of Tarski, and Jaskowski's theorem that intuitionistic logic enjoys the finite model property. Several questions of interest remain open. E.g., what is the intermediate logic of all closed triangulable manifolds?

Item Type: Pre-print
Report Nr: PP-2017-03
Series Name: Prepublication (PP) Series
Year: 2017
Subjects: Logic
Depositing User: Nick Bezhanishvili
Date Deposited: 18 Jan 2017 21:28
Last Modified: 18 Jan 2017 21:31
URI: https://eprints.illc.uva.nl/id/eprint/1520

Actions (login required)

View Item View Item