Re: help with dated entailments ... (for POWDER)

A short peice for review, particularly the last sentence:

http://www.w3.org/2007/OWL/wiki/POWDER#Validity_and_Dates

[[
A description resource, ddd, a member of ICEXT(I(wdr:DR)) may be either 
date-valid, or date-invalid (but not both), depending on the current 
date (today!), as follows:

     * If <ddd,f> is in IEXT(I(wdr:validFrom)) and f is after the 
current date, then

ddd is date-invalid.

     * If <ddd,u> is in IEXT(I(wdr:validUntil)) and u is before the 
current date, then

ddd is date-invalid.

     * Otherwise ddd is date-valid.

Additional constraints apply to interpretations of date-valid 
description resources, that do not apply to interpretations of 
date-invalid description resources. This step is regarded as pragmatic, 
lying on the border of the formal semantics.
]]


(elsewhere I will specify the additional constraints, essentially a 
subclass relationship)

Jeremy