Abstract
This chapter contains a proof of Lyndon's interpolation property (LIP) for quantified extensions of basic modal logics K, T, D, K4, and S4, and for some others, including the propositional S5 has LIP. At the same time, the quantified extension of S5, as well as other systems satisfying the Barcan formula has neither Lyndon's nor Craig's interpolation, nor Beth's property. Some examples of propositional modal logics, which have CIP but do not possess LIP are found. Craig's interpolation property is proved for a number of propositional modal logics, including the Grzegorczyk logic Grz, its extension Grz.2, and the provability logic G. A class of so-called L-conservative formulas is defined, which can be added to a propositional logic L as new axiom schemes without loss of interpolation. It is proved that the interpolation properties are preserved by transfer from predicate logics without equality to their extensions with equality.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.