Decomposition of Declarative Knowledge Bases With External Functions

Date Added: Jun 2009
Format: PDF

The authors present a method to decompose a declarative knowledge base, given by a logic program under answer set semantics with access to external sources. It overcomes the ineffectiveness of current methods due to a lack of structural information about these sources, viewed as black boxes, by exploiting independency information in accesses to them. To this end, they develop a generic notion of domain independence that allows to restrict the evaluation domain and, as a consequence, to prune unnecessary dependency assumptions between atoms. This leads to increased decomposability; they demonstrate this by an evaluation method for HEX-programs based on program rewriting, which may yield large performance gains.