There are many applications that require of complex structures to represent data, like the proposal for a multilingual Wikipedia [1] or a possible OpenMath implementation [2]. In Wikidata there is already support for 1-depth trees (qualifiers) and I am wondering if n-depth trees it is something that could be implemented in other namespaces, like multilingual statement, or math formula.

Would that be possible or are there better approaches?

Cheers, Micru

[1] http://meta.wikimedia.org/wiki/A_proposal_towards_a_multilingual_Wikipedia [2] http://en.wikipedia.org/wiki/Openmath#Example