Browsing Bulletin of the Section of Logic 48/1 (2019) by Title
Now showing items 3-5 of 5
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A Modified Subformula Property for the Modal Logic S4.2
(Wydawnictwo Uniwersytetu Łódzkiego, 2019)The modal logic S4.2 is S4 with the additional axiom ◊□A ⊃ □◊A. In this article, the sequent calculus GS4.2 for this logic is presented, and by imposing an appropriate restriction on the application of the cut-rule, it is ... -
Positive Implicative Soju Ideals in BCK-Algebras
(Wydawnictwo Uniwersytetu Łódzkiego, 2019)The notion of positive implicative soju ideal in BCK-algebra is introduced, and several properties are investigated. Relations between soju ideal and positive implicative soju ideal are considered, and characterizations ... -
Two Infinite Sequences of Pre-Maximal Extensions of the Relevant Logic E
(Wydawnictwo Uniwersytetu Łódzkiego, 2019)The only maximal extension of the logic of relevant entailment E is the classical logic CL. A logic L ⊆ [E,CL] called pre-maximal if and only if L is a coatom in the interval [E,CL]. We present two denumerable infinite ...