It's not easy to get to a true paradox with this collection. Not only do you have to be able to express it but you have to require that it exists.
Peter F. Patel-Schneider
On 12/02/2017 11:09 AM, mathieu stumpf guntz wrote:
Hi all,
You should in any case be sure to avoid allowing collections which fall in Russell's paradox https://en.wikipedia.org/wiki/Russell%27s_paradox. So if a predicate "belongs to collection QX" is added such that an Wikidata item can be stated as being part of an other, it must be envisionned that at some point a request my aske "What is the collection of items that do not belongs to themselves?".
Paradoxically logical, mathieu
Le 27/11/2017 à 02:07, Arthur Smith a écrit :
I think the general idea of documenting collections is a good one, though I haven't thought carefully about this or some of the responses already sent. However, I think the use of P361 (part of) for this purpose might not be a good idea and a new property should be proposed for it, or some other mechanism used for large collection handling (collections added through Mix n Match for example generally have external identifiers as their collection-specific properties). My concern here is mainly that the relationship is not generally going to be intrinsic to the item, and is more related to the project doing the import work, while P361 should generally describe some intrinsic relationship that an item has (for example a subsidiary being part of a parent company, a component of a device being part of the device, a research article being part of a particular journal issue, etc).
We do have a very new property that might be useable for this purpose, though it is intended to link to Wikiprojects rather than "collection" items - P4570 (Wikidata project). Or perhaps something similar should be proposed?
Arthur