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arXiv · 1605.01004

The Completeness Problem for Modal Logic

Antonis Achilleos
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Abstract

We introduce the completeness problem for Modal Logic and examine its complexity. For a definition of completeness for formulas, given a formula of a modal logic, the completeness problem asks whether the formula is complete for that logic. We discover that completeness and validity have the same complexity --- with certain exceptions for which there are, in general, no complete formulas. To prove upper bounds, we present a non-deterministic polynomial-time procedure with an oracle from PSPACE that combines tableaux and a test for bisimulation, and determines whether a formula is complete.

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Antonis Achilleos. 2016-05-03. The Completeness Problem for Modal Logic. https://doi.org/10.13140/rg.2.1.2373.6727

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