On Jan 22, 2011, at 6:16 PM, Pat Hayes wrote:
Slight amplification and very minor correction:
On Jan 18, 2011, at 5:58 PM, Christopher Menzel wrote:
The semantics of OWL per se does not accommodate the idea of a class's extension changing over time, although one could presumably capture the idea formally by means of a series of interpretations (thought of as temporally ordered) that assign different extensions to the same class. (This is possible because classes are not defined to be identical to their extensions in the semantics.
This last statement is true for OWL-Full but not for OWL-DL.
Eh? Is it not the case in the semantics for both OWL DL and OWL Full that OWL classes are simply introduced as the members of a distinguished set and that said classes are assigned extensions by the CEXT function? What am I missing?