Work

Metainferences, Invalidities and Contraction-Free Sequent Calculi for S5 and Carnap’s C

Year: 2026

Type: article

Abstract: This paper develops a sequent calculus framework for representing locally and globally valid metainferences through which contraction-free sequent calculi for the modal logics S5 and the propositional fragment of Carnap’s C are obtained. The sequent calculi allow for strongly terminating and backtracking-free proof search, features which in turn arguably explain why the decision problems for S5 and the propositional fragment of Carnap’s C are reducible to that of propositional classical logic.

Source: Journal of Philosophical Logic

DOI: 10.1007/s10992-026-09838-6

Author: Andreas Fjellstad

Institution: University of Padua

Language: English

Topic: Logic, Reasoning, and Knowledge

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $2,990

Funders: European Commission, Università degli Studi di Padova, NextGenerationEU