A Realistic Architecture for the Semantic Web

Abstract

Abstract. In this paper we argue that a realistic architecture for the Semantic Web must be based on multiple independent, but interoperable, stacks of languages. In particular, we argue that there is a very important class of rule-based languages, with over thirty years of history and experience, which cannot be layered on top of OWL and must be included in the Semantic Web architecture alongside with the stack of OWL-based languages. The class of languages we are after includes rules in the Logic Programming style, which support default negation. We briefly survey the logical foundations of these languages and then discuss an interoperability framework in which such languages can co-exist with OWL and its extensions.

RULES AS SIMPLE WAY TO MODEL KNOWLEDGE - Closing the Gap between Promise and Reality

“…The use of only one rule formalism obviously restricts the generality of any statements that can be made. However, F-logic is very similar to some of the rule languages under discussion for the Semantic Web (Kifer et al, 2005) and it is based on normal logic programs -probably the prototypical rule language. The authors examined literature and tools to ensure that tool support identified as missing is indeed missing from rule based systems and not only from systems supporting F-logic.…”

A Framework for Composition and Inter-operation of Rules in the Semantic Web

“…The need for these languages and their interaction have been discussed (e.g., [21,19]). It is also of note that many of the sublanguages of RuleML have been implemented either through translators (e.g., GEDCOM [12], which translates to XSB and JESS) or engines (e.g., j-DREW [24], a top-down engine for RuleML, DR-Device [3], an engine supporting defeasible logic and both strong and default negation, and CommonRules [11], a bottom-up engine for the Datalog sublanguage).…”

“…This requires a. the ability to exchange inference results between different knowledge bases (e.g., the interoperability problem between rules and OWL described in [19]); b. the ability to combine reasoning results produced by different reasoning engines; c. the ability to properly scope the reasoning w.r.t. a specific knowledge base (e.g., the scoped inference issue described in [19] …”

“…Various sublanguages have been created to include features like explicit equality (e.g., fologeq), negation as failure (e.g., naffolog), and Hilog layers (e.g., hohornlog). In [19], it is argued that any realistic architecture for the Semantic Web must be based on various independent but interoperable languages, one of them is the logic programming language with negation-as-failure. The next example illustrates this point.…”

Can OWL and Logic Programming Live Together Happily Ever After?

“…OWL and SWRL were criticized on these accounts in [4], and an alternative ontology language OWL-Flight, based entirely on logic programming, was proposed. In [14], the authors go even further by saying that a true rule formalism grounded in logic programming is intrinsically incompatible with OWL. They propose to change the layering architecture of the Semantic Web: instead of building rules on top of OWL, they propose OWL and rules to exist side-by-side, with semantic interoperability grounded in Description Logic Programs (DLP) [11]-a straightforward intersection of DLs and LP.…”