Semantic knowledge partitioning

Abstract

Some operations to decompose a knowledge base (considered as a first order logic formula) in ways so that only its semantics determines the results are investigated. Intended uses include the extraction of "parts" relevant to an application, the exploration and utilizing of implicit possibilities of structuring a knowledge base and the formulation of query answers in terms of a signature demanded by an application. A semantic framework based on Herbrand interpretations is outlined. The notion of "model relative to a scope" is introduced. It underlies the partitioning operations "projection" and "forgetting" and also provides a semantic account for certain formula simplification operations. An algorithmic approach which is based on resolution and may be regarded as a variation of the SCAN algorithm is discussed.