D16.1v0.2 The Web Service Modeling Language WSML

We introduce the Web Service Modeling Language WSML which provides a formal syntax and semantics for the Web Service Modeling Ontology WSMO. WSML is based on different logical formalisms, namely, Description Logics, First−Order Logic and Logic Programming, which are useful for the modeling of Semantic Web services. WSML consists of a number of variants based on these different logical formalisms, namely WSML−Core, WSML−DL, WSML−Flight, WSML−Rule and WSML−Full. WSML−Core corresponds with the intersection of Description Logic and Horn Logic (without function symbols and without equality), extended with datatype support in order to be useful in practical applications. WSML−Core is fully compliant with a subset of OWL. WSML−Core is extended, both in the direction of Description Logics and in the direction of Logic Programming, to WSML−DL and WSML−Flight. WSML−DL extends WSML−Core to an expressive Description Logic, namely, SHIQ, thereby covering that part of OWL which is efficiently implementable. WSML−Flight extends WSML−Core in the direction of Logic Programming. WSML−Flight has a rich set of modeling primitives for modeling different aspects of attributes, such as value constraints and integrity constraints. Furthermore, WSML−Flight incorporates a fully−fledged rule language, while still allowing efficient decidable reasoning. To be more precise, WSML−Flight allows to write down any Datalog rule, extended with inequality and (locally) stratified negation. WSML−Rule extends WSML−Flight to a fully−fledged Logic Programming language, including function symbols. WSML−Rule no longer restricts the use of variables in logical expressions. The final WSML variant unifies the Description Logic and Logic Programming paradigms. WSML−Full unifies all WSML variants under a common First−Order umbrella with non−monotonic extensions which allow to capture nonmonotonic negation of WSML−Rule. All WSML variants are described in terms of a normative human−readable syntax. Besides the human−readable syntax we provide an XML and an RDF syntax for exchange between machines. Furthermore, we provide a mapping between WSML ontologies and OWL for basic inter−operation with OWL ontologies through a common semantic subset of OWL and WSML. This deliverable supersedes a number of now obsolete WSML deliverables. References to these now obsolete deliverables can be found at: