  We introduce a new semantics for a logic of explicit and implicit beliefs
based on the concept of multi-agent belief base. Differently from existing
Kripke-style semantics for epistemic logic in which the notions of possible
world and doxastic/epistemic alternative are primitive, in our semantics they
are non-primitive but are defined from the concept of belief base. We provide a
complete axiomatization and prove decidability for our logic via a finite model
argument. We also provide a polynomial embedding of our logic into Fagin &
Halpern's logic of general awareness and establish a complexity result for our
logic via the embedding.
