On the characterizability of the frames for the ``unpreventability of the present and the past''
type: Item
instance of: scholarly article
title: On the characterizability of the frames for the ``unpreventability of the present and the past''
zbMATH Open document ID: 0624.03017
author: Alberto Zanardo
published in: Notre Dame Journal of Formal Logic
publication date: 1986-01-01T00:00:00Z
review text: The language \({\mathcal L}_{MT}\) is obtained by adding the modal operator \(\diamond\), the past operator P and the future operator F to classical propositional logic. Formulas of \({\mathcal L}_{MT}\) are interpreted in frames that carry both a linear order and an accessibility relation. The author introduces the class \({\mathcal F}_ N\) of neutral frames guided by the intension, that \(\diamond \phi \leftrightarrow \square \phi\) should be true in all neutral frames for all formulas \(\phi\) not containing F. The objective of the paper is to show the non-characterizability in \({\mathcal L}_{MT}\) of certain subclasses of \({\mathcal F}_ N\).
Mathematics Subject Classification ID: 03B45
zbMATH DE Number: 4012577
zbMATH Keywords: modal logic
zbMATH Keywords: tense logic
zbMATH Keywords: characterizability
zbMATH Keywords: frames
MaRDI profile type: Publication
full work available at URL: https://doi.org/10.1305/ndjfl/1093636769
OpenAlex ID: W1986076408
DOI: 10.1305/NDJFL/1093636769
description: scientific article; zbMATH DE number 4012577