RE: SEM: comprehensive entailments without dark triples

> Consider the following KB:
>
> KB1:
>
> 	John rdf:type Person .
> 	John rdf:type :_1 .
> 	:_1 daml:onProperty child .
> 	:_1 daml:cardinality "0" .
>
> As John has no children it seems to me that it should be a theorem of the
> logical system that John belongs to any value restriction on child.
>
> However, this is not the case.
> Consider the following KBs:
>
> KB2:
>
> 	:_2 daml:onProperty child .
> 	:_2 daml:toClass Person .
>
> KB3:
>
> 	:_3 daml:onProperty child .
> 	:_3 daml:toClass :_3.
>
> KB1 entails KB2, but does not entail KB3.
>

That's a nice example, that I think captures some of the differences. (I am happy with the strangeness of this state of affairs, I
can see others may not be).

Jeremy