“…Beyond the embedding of CL-PC that we have recalled in Sect. 3.5, the central role of DL-PA is confirmed by DL-PA accounts of update and revision operations [54], belief merging operations [63], abstract argumentation theories and their modification [33], and answer-set programs and their modification [36]; moreover, its epistemic extension, public announcement logic with assignments, solves the epistemic frame problem [114,115]. As to logics with epistemic operators, we have recalled that S5 is inadequate as a logic of knowledge and should be replaced by S4.2; furthermore, we have shown that the definition of common knowledge by means of the Greatest Fixpoint Axiom GFP(CK J ) is at least questionable.…”