Strong Completeness Theorems for Weak Logics of Common Belief

P. MONGIN, L. Lismont

Journal of Philosophical Logics

2003, vol. 32, pp.115-137

Départements : Economie et Sciences de la décision, GREGHEC (CNRS)

We show that several logics of common belief and common knowledge are not only complete, but also strongly complete, hence compact. These logics involve a weakened monotonicity axiom, and no other restriction on individual belief. The semantics is of the ordinary fixed-point type