On Characterization, Definability and ω-Saturated Models
نویسنده
چکیده
Two important classic results about modal expressivity are the Characterization and Definability theorems. We develop a general theory for modal logics below first order (in terms of expressivity) which exposes the following result: Characterization and Definability theorems hold for every (reasonable) modal logic whose ω-saturated models have the Hennessy-Milner property. The results are presented in a general version which is relativized to classes of models.
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Characterization, definability and separation via saturated models
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