Merging uncertain knowledge bases in a possibilistic logic framework

This paper addresses the problem of merg­ ing uncertain information in the framework of possibilistic logic. It presents several syn­ tactic combination rules to merge possibilis­ tic knowledge bases, provided by different sources, into a new possibilistic knowledge base. These combination rules are first de­ scribed at the meta-level outside the lan­ guage of possibilistic logic. Next, an exten­ sion of possibilistic logic, where the combi­ nation rules are inside the language, is pro­ posed. A proof system in a sequent form, which is sound and complete with respect to the possibilistic logic semantics, is given.