Because Mike was late in getting them out, we'll review the minutes from May 22 next week.
Mike found several messages containing DAML issues for RDF:
Additional RDF Issues relevant to DAML include
There was considerable discussion about reification. The term may be over-used in the RDF community. Pat sees no problem with data structuring (building more complex graph structure out of triples) but doesn't think that should be called reification. Quoting is a traditional way in logic of representing reification.
There was no consensus on whether we would prefer that reification be removed from RDF, but it was agreed that DAML+OIL has no dependency on reification
There was general agreement that use of rules will inevitably make the DAML language undecidable.
Peter's goal was to provide the minimal extension that would be useful. In particular, he only allows a single antecedent (analogous to guarded fragments or safety conditions on Horn clauses, Crawford and Allen's access-limited logic, and other attempts to make Horn clauses more computationally tractable).
There was considerable discussion of how the "class semantics" relate to the "rule semantics" and how this affects the complexity. Stefan suggested that by basing rules at the RDFS layer (rather than DAML+OIL), we might avoid the "hybrid semantics". In contrast, Dan would like to express some of the axiomatic semantics as rules. Ian suggested that these may be implementation issues rather than language definition issues. There was consensus that the DAML+OIL documentation should note that DAML doesn't require completeness (e.g. the ability of rules to affect classification).
Stefan referred people to CARIN, which combines Horn Rules and Description Logics.
ACTION (everyone): review the current DAML FAQ and be prepared to discuss fixes, additions, etc. before we make it public.
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