Subject: [LC response] To Umberto Straccia
Thank you for your comment
on the OWL 2 Web Ontology Language last call drafts.
Unfortunately, adding syntactic sugar does have a significant specification and consensus building cost. Similar syntactic sugar has already been objected to by some communities (see, e.g., ). Therefore the working group has decided not to augment the language with the ObjectImplicationOf constructor at this time.
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I kindly ask to take into consideration the possibility to allow, among the propositional connectives involved in ClassExpression (ObjectIntersectionOf, ObjectUnionOf, and ObjectComplementOf), a conditional Concept expression ObjectImplicationOf
where C, D are ClassExrpessions
Under classical semantics, implication is just a macro in terms of union and negation,
ObjectImplicationOf(C D) is the same as ObjectUnionOf(ObjectComplementOf(C) D),
so is syntactic sugar.
This is, however not true in general in a "fuzzy OWL" setting and, thus, this kind of expressions cannot be represented in OWL 2.