Schröder , LutzPattinson, Dirk2015-12-130955-792Xhttp://hdl.handle.net/1885/79478Coalgebras provide a unifying semantic framework for a wide variety of modal logics. It has previously been shown that the class of coalgebras for an endofunctor can always be axiomatized in rank 1. Here we establish the converse, i.e. every rank-1 modalKeywords: Coalgebras; Decision procedure; Deontic Logic; Modal logic; Neighbourhood; Machinery; Formal logic coalgebra; decision procedures; deontic logic; Modal logic; neighbourhood framesRank-1 modal logics are coalgebraic201010.1093/logcom/exn0962016-02-24