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arXiv · 1601.05656

Proving Craig and Lyndon Interpolation Using Labelled Sequent Calculi

Roman Kuznets
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Abstract

We have recently presented a general method of proving the fundamental logical properties of Craig and Lyndon Interpolation (IPs) by induction on derivations in a wide class of internal sequent calculi, including sequents, hypersequents, and nested sequents. Here we adapt the method to a more general external formalism of labelled sequents and provide sufficient criteria on the Kripke-frame characterization of a logic that guarantee the IPs. In particular, we show that classes of frames definable by quantifier-free Horn formulas correspond to logics with the IPs. These criteria capture the modal cube and the infinite family of transitive Geach logics.

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Roman Kuznets. 2016-01-21. Proving Craig and Lyndon Interpolation Using Labelled Sequent Calculi. https://doi.org/10.1007/978-3-319-48758-8_21

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