Model Based Horn Contraction
نویسندگان
چکیده
Following the recent trend of adapting the AGM (Alchourrón and Makinson 1985) framework to propositional Horn logic, Delgrande and Peppas (Delgrande and Peppas 2011) give a model theoretic account for revision in the Horn logic setting. The current paper complements their work by studying the model theoretic approach for contraction. A model based Horn contraction is constructed and shown to give a model theoretic account to the transitively relational partial meet Horn contraction studied in (Zhuang and Pagnucco 2011). Significantly however, in contrast to (Delgrande and Peppas 2011), our model-based characterisation of Horn contraction does not require the property of Horn compliance and totality over preorders. The model based contraction, upon proper restriction, also gives a model theoretic account for the epistemic entrenchment based Horn contraction studied in (Zhuang and Pagnucco 2010a).
منابع مشابه
Definability of Horn Revision from Horn Contraction
In the AGM framework [Alchourrón and Makinson, 1985], a revision function can be defined directly through constructions like systems of spheres, epistemic entrenchment, etc., or indirectly through a contraction operation via the Levi identity. A recent trend is to construct AGM style contraction and revision functions that operate under Horn logic. A direct construction of Horn revision is give...
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