From: Ian Horrocks (horrocks@cs.man.ac.uk)
Date: 12/26/00
I think this is covered by the "ID" versus "about" answer - the names are just URIs and although it is good style to declare them it is not mandatory. It is certainly legal from a daml+oil perspective to use undeclared class and property names. Ian On December 25, Frank van Harmelen writes: > > In the ammended version of our introductory example (at http://www.cs.vu.nl/~frankh/spool/DAML+OIL/daml+oil-ex.daml) there are a few places where I refer to a property without having declared it as a property first. > > For example: > > <rdfs:Class rdf:about="#Person"> > <restrictedBy> > <Restriction> > <onProperty rdf:resource="#spouse"/> > <maxcardinalityQ>1</maxcardinalityQ> > <hasClassQ rdf:resource="#Person"/> > </Restriction> > </restrictedBy> > </rdfs:Class> > > places a qualified cardinality restriction on the property spouse applied to persons, while there has never been a statement declaring spouse to be a property, ie nothing like > <rdf:Property rdf:ID="spouse/> > appears anywhere (earlier or later) in the file. > > QUESTION: is this legal? In DAML? In RDF? in RDF Schema? > > The same happens with a class that is mentioned but never defined: > > <Disjoint parseType="daml:collection"> > <rdfs:Class rdf:about="#Car"> > <rdfs:Class rdf:about="#Person"> > <rdfs:Class rdf:about="#Plant"> > </Disjoint> > > appears without there ever being anywere anything like: > > <rdfs:Class rdf:ID="Plant"/> > > SAME QUESTION. > > Frank. > ----
This archive was generated by hypermail 2.1.4 : 04/02/02 EST