Abstract : We consider the existential rule framework, which generalizes Horn description logics. We study and compare several boundedness notions in this framework. Our main result states that (strongly-) bounded rules are exactly those at the intersection of two well-known abstract classes of existential rules, namely fes (finite expansion sets, which ensure the finiteness of the core chase) and fus (finite unification sets, which correspond to UCQ-rewritable rules).
