A Model Theory for the Potential Infinite Cover Image

A Model Theory for the Potential Infinite
A Model Theory for the Potential Infinite

Author(s): Matthias Eberl
Subject(s): Logic, Philosophy of Science
Published by: Wydawnictwo Uniwersytetu Jagiellońskiego
Keywords: Finitism; potential infinite; model theory; first order logic; reflection principle;

Summary/Abstract: We present the model theoretic concepts that allow mathematics to be developed with the notion of the potential infinite instead of the actual infinite. The potential infinite is understood as a dynamic notion, being an indefinitely extensible finite. The main adoption is the interpretation of the universal quantifier, which has an implicit reection principle. Each universal quantification refers to an indefinitely large, but finite set. The quantified sets may increase, so after a reference by quantification, a further reference typically uses a larger, still finite set. We present the concepts for classical first-order logic and show that these dynamic models are sound and complete with respect to the usual inference rules. Moreover, a finite set of formulas requires a finite part of the increasing model for a correct interpretation.

  • Issue Year: 2022
  • Issue No: 57
  • Page Range: 3-30
  • Page Count: 28
  • Language: English