Infinitary propositional normal modal logic
The author introduces a propositional normal modal logic, denoted by \(KL_{\omega_ 1}\), with countable conjunction and disjunction. He gives the Hilbert type formulation of \(KL_{\omega_ 1}\), defines the class of Kripke frames characteristic for this logic (completeness theorem) and proves that \(KL_{\omega_ 1}\) has the Craig interpolation property.
scientific article; zbMATH DE number 4049616