[Bug 6644] Context determined type table

http://www.w3.org/Bugs/Public/show_bug.cgi?id=6644





--- Comment #5 from Hans-Juergen Rennau <hrennau@yahoo.de>  2009-04-16 21:32:34 ---
(In reply to comment #4)

Yes, you are right - therefore dropping clause 2.2 would have to be combined
with a modification of 3.4.4.5 Conditional Type Substitutable in Restriction.
This modification would distinguish the special case you pointed at - "B has a
type table and T has not" - and use in this case instead of ST a T_T
constructed "on the fly" from T.{type definition}, just as CDTT presently is
always constructed. And in a similar way one would have to handle a second
special case: "B has no type table but T has, and derivation mode is
extension".

But one can get the same result in a much simpler way: 
a) leave the definition of CDTT as it is
b) add a special clause to 3.4.4.5 which states the constraint to be satisfied
if neither B nor T has a type table. 

So please REPLACE THE PROPOSAL made in comment #3 by the following ...

Proposal:
====================================
Change 3.4.4.5 in the following way:
a) 
After "E and T satisfy this constraint if and only if one of the following is
true", insert:
1. T.{type table} is absent, and B.{type table} is absent

b) 
Accordingly renumber the presently existing clauses, that is, increment their
numbering by 1, to get:
2 Tb does not exist (i.e. E has no context-determined type table in B)
3 TT and TB both exist ...
etc.
====================================

Motivation:
====================================
1. The purpose of 3.4.4.5 - as stated in the Note immediately following it -
would still be fully met
2. This side effect would be removed: erratically making instances invalid in
cases where no type tables are involved.
====================================


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Received on Thursday, 16 April 2009 21:32:42 UTC