Chagrov, A. V. Undecidable properties of superintuitionistic logics. (Russian) Zbl 0840.03018 Mat. Vopr. Kibern. 5, 62-108 (1994). A property \(P\) of superintuitionistic logics (i.e., extensions of intuitionistic propositional logic Int) is decidable if there is an algorithm recognizing, given a formula \(A\), whether \(\text{Int} + A\) has \(P\) or not. The paper develops methods for proving the undecidability of properties of those logics and applies them in many particular cases. Undecidable properties of modal logics containing S4 and K4 are also discussed. Reviewer: M.Zakharyaschev (Berlin) Cited in 6 Documents MSC: 03B55 Intermediate logics 03B45 Modal logic (including the logic of norms) 03B25 Decidability of theories and sets of sentences Keywords:undecidability of properties of logics; superintuitionistic logics; modal logics PDFBibTeX XMLCite \textit{A. V. Chagrov}, Mat. Vopr. Kibern. 5, 62--108 (1994; Zbl 0840.03018)