Cdmtcs Research Report Series Computable Kripke Models and Intermediate Logics

Truth Values and Connectives in Some Non-Classical Logics

The question as to whether the propositional logic of Heyting, which was a formalization of Brouwer's intuitionistic logic, is finitely many valued or not, was open for a while (the question was asked by Hahn). Kurt Gödel (1932) introduced an infinite decreasing chain of intermediate logics, which are known nowadays as Gödel logics, for showing that the intuitionistic logic is not finitely (man...

Cdmtcs Research Report Series the Hausdorr Measure of Regular !-languages Is Computable 1

Hypersequent Calculi for some Intermediate Logics with Bounded Kripke Models

In this paper we define cut-free hypersequent calculi for some intermediate logics semantically characterized by bounded Kripke models. In particular we consider the logics characterized by Kripke models of bounded width Bwk, by Kripke models of bounded cardinality Bck and by linearly ordered Kripke models of bounded cardinality Gk. The latter family of logics coincides with finite-valued Gödel...

Krlpke Models and Intermediate Logics

In [10], Kripke gave a definition of the semantics of the intuitionistic logic. Fitting [2] showed that Kripke's models are equivalent to algebraic models (i.e., pseudo-Boolean models) in a certain sense. As a corollary of this result, we can show that any partially ordered set is regarded as a (characteristic) model of a intermediate logic ̂ We shall study the relations between intermediate log...

Cdmtcs Research Report Series Eective Presentability of Boolean Algebras of Cantor{bendixson Rank 1 Eective Presentability of Boolean Algebras of Cantor{bendixson Rank 1

We show that there is a computable Boolean algebra B and a computably enumerable ideal I of B such that the quotient algebra B=I is of Cantor{Bendixson rank 1 and is not isomorphic to any computable Boolean algebra. This extends a result of L. Feiner and is deduced from Feiner's result even though Feiner's construction yields a Boolean algebra of in nite Cantor{Bendixson rank.