interpretation of DataPropertyDomain and Datarange

Hi,

Dataproperties have an interpretation in (deltaI x deltaD). Datatypes have an 
interpretation in a portion of deltaD^2 that matches their arity. The 
interpretation of DatatypePropertyRange therefore seems to be trying to do a 
badly-typed sub-set operation: y::deltaD < DR^D::deltaD^2 which upsets my 
typechecker :)

Is this me missreading what's going on? Either deltaD should include all 
tuples (which I guess makes it a badly-behaved set) or the interpretation of 
DataProperty should be in (deltaI x deltaD^2).

Matthew