I'm thinking of possible ways to represent constraints as items (see [1]),
like those in:
https://www.wikidata.org/wiki/Property_talk:P19
However some of these are not easy to translate into Wikidata proper. For
example:
<place of birth (P19)> Conflicts with <instance of (P31): criminal delict
(Q1456832)>
With the current tools it could be expressed as convolutely as wished for,
but it won't be compatible with the semantic web.
Of course it would be much nicer and compatible to implement OWL2 property
restrictions (some_values_from, all_values_from, none_of, etc) as snak
types which could be re-used for any property. Then it would be as easy as:
<place of birth (P19)>
property restriction [none of]
<instance of (P31): criminal delict (Q1456832)>
Thoughts?
Cheers,
Micru
[1]
https://www.wikidata.org/wiki/Wikidata:Constraint_violation_report_input
[2]
http://www.w3.org/TR/owl2-syntax/#Object_Property_Restrictions