WSML – a Language for WSMO - Enabling Semantic Web Services: The Web Service Modeling Ontology - page 90

a translation from the human-readable syntax. Because of space limita-
tions, we give only a partial example (Listing 7.3) of the XML version of
the WSML example in Listing 7.1. The complete translation can be found
in [30]. Typically, WSML keywords, which are in the WSML namespace
( http://www.wsmo.org/wsml/wsml-syntax# ), map to XML elements. Note also
that sQNames are written as full IRIs in XML. We have defined the WSML
XML syntax in the form of an XML Schema. 6 The XML syntax for logical
expressions is close to RuleML, and we expect further alignment between the
two initiatives in the next version.

< ! ENTITY book ”http://example.org/bookOntology#” >
< wsml xmlns=”http://www.wsmo.org/wsml/wsml − syntax#
variant =”http://www.wsmo.org/wsml/wsml − syntax/wsml − flight” >
< ontology name=”http://example.org/bookOntology” >
< nonFunctionalProperties >
< attributeValue name=”http://purl.org/dc/elements/1.1/title” >
< value type=”http://www.wsmo.org/wsml/wsml

− syntax#string” >

Example Book Ontology
< /value >
[..]
< /attributeValue >
< /nonFunctionalProperties >
< concept name=”&book;book” >
< nonFunctionalProperties > [..] < /nonFunctionalProperties >
< attribute name=”&book;title” type=”constraining” >
< range > http://www.wsmo.org/wsml/wsml − syntax#string < /range >
< /attribute >
[..]
< /concept >
[..]
< /ontology >
< /wsml >

Listing 7.3. WSML XML example

7.4.2 The WSML RDF Syntax

The Resource Description Framework (RDF) 7 defines a data structure based
on triples for metadata description on the Web. RDF Schema [20] is a simple
ontology language intended to provide a vocabulary for RDF descriptions.
WSML provides a serialization in RDF of all its conceptual modeling
elements. The WSML RDF syntax reuses and extends the RDF Schema
vocabulary to allow existing RDF(S)-based tools to understand parts of a
WSML specification. For logical expressions, we reuse the XML serialization
of WSML, since an encoding of complex constructs does not fit well into the
RDF triple-based data model.
Owing to limited space, we show here only a small example of the WSML
RDF syntax, in Listing 7.4. The complete RDF serialization of WSML and
a larger example can be found in [30]. In Listing 7.4, “rdf” stands for the

6 http://www.wsmo.org/TR/d16/d16.1/v0.21/xml-syntax/wsml-xml-syntax.
xsd .
7 http://www.w3.org/RDF .