We will study syntactical and semantical properties of propositional logics weaker than the
intuitionistic, in which the contraction rule (or, the exchange rule or the weakening rule, in …

From the point of view of non-classical logics, Heyting's implication is the smallest
implication for which the deduction theorem holds. This book studies properties of logical …

This chapter is a continuation of the preceding one, and we begin it at the place where the
authors of Basic Modal Logic left us about fifteen years ago. Concluding his historical …

For intermediate logics, there is obtained in the paper an algebraic equivalent of the
disjunction property DP. It is proved that the logic of finite binary trees is not maximal among …

It is proved that there are exactly 16 superintuitionistic propositional logics with the projective
Beth property. These logics are finitely axiomatizable and have the finite model property …

Coming from I and Cl, ie from intuitionistic and classical propositional calculi with the
substitution rule postulated, and using the sign ο to add a new connective there have been …

As stated in the survey\J3T\by Hosoi and the author, many works have been done during the
last decade on the propositional logics between the classical and the intuitionistic (the …

The disjunction property of intermediate propositional logics Page 1 ALEXANDER CHAGROV
~VIICHAEL ZAKHARYASHCHEV The Disjunction Property of Intermediate Propositional Logics …

This paper is the concluding part of [1] and [2], and it investigates the inner structure of the
lattice Λ (MHA) of all varieties of monadic Heyting algebras. For every n≤ ω, we introduce …

Let a logical propositional calculus L 0 be given. We consider arbitrary extensions of L 0 by
adding finitely many new axiom schemes and rules of inference. We say that a property of P …