Models for the Lambek calculus of syntactic categories surveyed here are based on frames that are in principle of the same type as Kripke frames for intuitionistic logic. These models are extractedâ€¦ (More)

This paper, a sequel to "Models for normal intuitionistie modal logics" by M. Bo~i6 and the author, which dealt with intuitionistic analogues of the modal system K, deals similarly withâ€¦ (More)

The generality of a derivation is an equivalence relation on the set of occurrences of variables in its premises and conclusion such that two occurrences of the same variable are in this relation ifâ€¦ (More)

The purpose of this paper is to connect the proof theory and the model theory of a family of propositional logics weaker than Heyting's. This family includes systems analogous to the Lambek calculusâ€¦ (More)

This is a review. with historical and critical comments, of a paper b) I. E. Orlov from 1928, which eivcs the oldest known axiomatization of the implicationnegation fragment of the rclcvant logic R.â€¦ (More)

This paper presents a proof-theoretical approach to the question "What is a logical constant?" This approach starts with the assumption that logic is the science of formal deductions, and that basicâ€¦ (More)