An observation concerning porte's rule in modal logic

Rohan French; Ian Lloyd Humberstone

An observation concerning porte's rule in modal logic

Rohan French, Ian Lloyd Humberstone

Philosophy

Research output: Contribution to journal › Article › Research › peer-review

2 Citations (Scopus)

Abstract

It is well known that no consistent normal modal logic contains (as theorems) both ♦A and ♦A (for any formula A). Here we observe that this claim can be strengthened to the following: for any formula A, either no consistent normal modal logic contains ♦ A, or else no consistent normal modal logic contains ♦-A.

Original language	English
Pages (from-to)	25 - 31
Number of pages	7
Journal	Bulletin of the Section of Logic
Volume	44
Issue number	1-2
Publication status	Published - 2015

Cite this

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title = "An observation concerning porte's rule in modal logic",

abstract = "It is well known that no consistent normal modal logic contains (as theorems) both ♦A and ♦A (for any formula A). Here we observe that this claim can be strengthened to the following: for any formula A, either no consistent normal modal logic contains ♦ A, or else no consistent normal modal logic contains ♦-A.",

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AB - It is well known that no consistent normal modal logic contains (as theorems) both ♦A and ♦A (for any formula A). Here we observe that this claim can be strengthened to the following: for any formula A, either no consistent normal modal logic contains ♦ A, or else no consistent normal modal logic contains ♦-A.

UR - http://rohan-french.github.io/writing/porte.pdf

UR - https://www.scopus.com/pages/publications/84937398648

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JO - Bulletin of the Section of Logic

JF - Bulletin of the Section of Logic

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An observation concerning porte's rule in modal logic

Abstract

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Cite this