Circumscription in a Modal Logic
نویسنده
چکیده
In this paper, we extend circumscription [McCarthy, 80] to a propositional modal logic of knowledge of one agent. Instead of circumscribing a predicate, we circumscribe the knowledge operator "K" in a formula. In order to have a nontrivial circumscription schema, we extend $5 modal logic of knowledge by adding another modality "Val" and a universal quantifier over base sentences (sentences which do not contain modality). Intuitively, "Val(P)" means that P is a valid formula. It turns out that by circumscribing the knowledge operator in a formula, we completely characterize the maximally ignorant models of the formula (models of the formula where agents have minimal knowledge).
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تاریخ انتشار 1988