Open World makes first thing in an OrderedCollection indeterminate

[marksem]

Given the open world assumption, it is not possible to tell which is the first thing in an OrderedCollection just by looking for the absence of a predecessor. We may want an explicit hasFirstMember type property to remove this ambiguity and make it easy to find the first member of an OrderedCollection.

[rjyounes]

Excellent point from @stewardont. I'm in favor of this.

[rjyounes]

DECISION: Add hasFirstMember predicate - subproperty of hasMember, domain is OrderedCollection, range is OrderedMember. Not a functional property since ordered collections are not necessarily strictly ordered.

[rjyounes]

Fixed in PR #667.