On Fri, Jul 11, 2014 at 8:35 PM, Peter F. Patel-Schneider < pfpschneider@gmail.com> wrote: > The "meaning" of this shape expression is, roughly, a node of shape > <Person> has an rdf:type link to :Person and at most one :spouse link, and > the target of the :spouse link is a node of shape <Person>. I say roughly > here because of the recursive nature of this expression - there is a > decided question as to how this sort of recursion is defined in general, > which appears to have been answered in a particular way here, although the > formal underpinnings here do not appear to support recursion. > > So, a node of shape <Person> does have at most one spouse here - as > opposed to the situation for (all :spouse :Person) - and all spouses must > have shape <Person> - as opposed to the situation for (exists :spouse > :Person). Yes, the declaration is saying that. The cardinality "?" says that a node with Shape Person "can" have at most a spouse of shape Person. With regards to recursion, I think it is a matter of selecting a formal system that supports recursion. That's why I opted for an operational semantics inspired in the type inference systems of programming languages. Best regards, Jose LabraReceived on Friday, 11 July 2014 19:26:46 UTC
This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 17:02:39 UTC