4 found
  1.  52
    Modal logics of domains on the real plane.V. B. Shehtman - 1983 - Studia Logica 42 (1):63-80.
    This paper concerns modal logics appearing from the temporal ordering of domains in two-dimensional Minkowski spacetime. As R. Goldblatt has proved recently, the logic of the whole plane isS4.2. We consider closed or open convex polygons and closed or open domains bounded by simple differentiable curves; this leads to the logics:S4,S4.1,S4.2 orS4.1.2.
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  2.  37
    Maximal Kripke-type semantics for modal and superintuitionistic predicate logics.D. P. Skvortsov & V. B. Shehtman - 1993 - Annals of Pure and Applied Logic 63 (1):69-101.
    Recent studies in semantics of modal and superintuitionistic predicate logics provided many examples of incompleteness, especially for Kripke semantics. So there is a problem: to find an appropriate possible- world semantics which is equivalent to Kripke semantics at the propositional level and which is strong enough to prove general completeness results. The present paper introduces a new semantics of Kripke metaframes' generalizing some earlier notions. The main innovation is in considering "n"-tuples of individuals as abstract "n"-dimensional vectors', together with some (...)
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  3.  52
    Undecidability of modal and intermediate first-order logics with two individual variables.D. M. Gabbay & V. B. Shehtman - 1993 - Journal of Symbolic Logic 58 (3):800-823.
  4.  22
    Logics of some kripke frames connected with Medvedev notion of informational types.V. B. Shehtman & D. P. Skvortsov - 1986 - Studia Logica 45 (1):101-118.
    Intermediate prepositional logics we consider here describe the setI() of regular informational types introduced by Yu. T. Medvedev [7]. He showed thatI() is a Heyting algebra. This algebra gives rise to the logic of infinite problems from [13] denoted here asLM 1. Some other definitions of negation inI() lead to logicsLM n (n ). We study inclusions between these and other systems, proveLM n to be non-finitely axiomatizable (n ) and recursively axiomatizable (n ). We also show that formulas in (...)
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