ISSUE-228: Draft response

Here is a possible response to the second part of Peter's issue on 
validation reports, see

https://lists.w3.org/Archives/Public/public-rdf-shapes/2017Feb/0001.html


Hi Peter,

 > The second problem is the form of a validation report.  There is
 > insufficient guidance on how multiple validation results are to be
 > produced.  For example, can a single validation result have multiple 
values
 > for sh:value, making it a validation report for multiple violations?

I have meanwhile added clarification that sh:value (with all other 
relevant result properties) can only have max one value. I have also 
added this new sentence (as mentioned for ISSUE-225):

---
Furthermore, the validators always produce/new/result nodes, i.e. when 
the textual definition states that "...a validation result/must/be 
produced..." then this refers to a distinct new node in a results graph.
---

which excludes the case of sharing sh:value among result nodes.

 > Similarly, if a shape has two sh:ClassConstraintComponent 
constraints, can
 > a single validation report be used for violations from both of them?

No, this case is excluded from the current definitions.


Please let me know where this response could be improved.

Thanks,
Holger