{ "id": "1805.09437", "version": "v1", "published": "2018-05-23T21:39:30.000Z", "updated": "2018-05-23T21:39:30.000Z", "title": "Relational Hypersequents for Modal Logics", "authors": [ "Samara Burns", "Richard Zach" ], "categories": [ "math.LO", "cs.LO" ], "abstract": "We investigate a new approach to modal hypersequents, called relational hypersequents, which incorporates an accessibility relation along the hypersequent. These systems are an adaptation of Restall's 2009 cut-free complete hypersequent system for S5. Variation between modal systems in the relational framework occurs only in the presence or absence of structural rules, which conforms to Do\\v{s}en's principle. All systems are modular except for that of S5. We provide the first cut-free completeness result for K, T, and D, and show how this method fails in the case of B and S4.", "revisions": [ { "version": "v1", "updated": "2018-05-23T21:39:30.000Z" } ], "analyses": { "subjects": [ "03B45", "03F05" ], "keywords": [ "relational hypersequents", "modal logics", "first cut-free completeness result", "cut-free complete hypersequent system", "relational framework occurs" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }