Issue 302: Graph edges that don't terminate

I propose we close this issue[1] as a duplicate of ( part of ) Issue
353[2] which is classed as editorial. This editor is aware of the
problem and is working on wording to clarify the intent ( which is to
deal with null pointers/references in object graphs )

Gudge

[1] http://www.w3.org/2000/xp/Group/xmlp-lc-issues.html#x302
[2] http://www.w3.org/2000/xp/Group/xmlp-lc-issues.html#x353