@inproceedings{discovery10141795, address = {Cham, Switzerland}, note = {This version is the author accepted manuscript. For information on re-use, please refer to the publisher's terms and conditions.}, volume = {13038}, pages = {388--407}, booktitle = {Logic, Language, Information, and Computation. WoLLIC 2021. Lecture Notes in Computer Science}, series = {Lecture Notes in Computer Science}, month = {October}, journal = {Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)}, publisher = {Springer}, year = {2021}, title = {A Pure View of Ecumenical Modalities}, abstract = {Recent works about ecumenical systems, where connectives from classical and intuitionistic logics can co-exist in peace, warmed the discussion on proof systems for combining logics. This discussion has been extended to alethic modalities using Simpson's meta-logical characterization: necessity is independent of the viewer, while possibility can be either intuitionistic or classical. In this work, we propose a pure, label free calculus for ecumenical modalities, nEK, where exactly one logical operator figures in introduction rules and every basic object of the calculus can be read as a formula in the language of the ecumenical modal logic EK. We prove that nEK is sound and complete w.r.t. the ecumenical birelational semantics and discuss fragments and extensions.}, issn = {1611-3349}, author = {Marin, S and Pereira, LC and Pimentel, E and Sales, E}, url = {https://doi.org/10.1007/978-3-030-88853-4\%5f24} }