A Practical Approach to Fusing Prioritized Knowledge Bases

This paper investigates simple well behaved syntactic methods to fuse prioritized knowledge bases which are semantically meaningful in the frameworks of possibility theory and of Spohn’s ordinal conditional functions. Different types of scales for priorities are discussed: finite vs. infinite, numerical vs. ordinal. Syntactic fusion is envisaged here as a process which combines prioritized knowledge bases into a new prioritized knowledge base, and thus allows for subsequent iteration. Several fusion operations are proposed, according to whether or not the sources are dependent, or conflicting, or sharing the same scale.