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Re: complete checkers should or MUST pass tests

From: Sandro Hawke <sandro@w3.org>
Date: Mon, 12 May 2003 06:44:52 -0400
Message-Id: <200305121044.h4CAiqqf009212@roke.hawke.org>
To: Jeremy Carroll <jjc@hplb.hpl.hp.com>
cc: WebOnt WG <www-webont-wg@w3.org>


Jeremy Carroll wrote:
> Sandro Hawke wrote:
> >>A complete OWL Lite consistency checker or a complete OWL DL
> >>consistency checker should not return Unknown  
> >>
> >                       ^^^^^^^^^^  MUST NOT
> 
> 
> This comment concerns section 5.2 of the test cases
> 
> http://www.w3.org/2002/03owlt/editors-draft/draft/#runningConsistencyChecker
> 
> which is currently informative and also does not have RFC 2119 in scope to 
> define the word MUST. The choice of the word "should" was intended to 
> reflect the constraints on a complete consistency checker from 4.2.2
> 
> If we wanted to make this change I would suggest the following:
> 
> In the quoted text replace "should not" by "must not"
> 
> In the normative section
> http://www.w3.org/2002/03owlt/editors-draft/draft/#consistencyChecker
> 
> Add the following after the definitions of complete OWL Lite and complete 
> OWL DL consistency checkers.
> 
> [[
> A complete consistency checker MUST NOT return unknown on any of the 
> relevant normative consistency and inconsistency tests in this document.
> ]]
> 
> 
> Sandro,
> 
> is that what you wanted?

The change seemed editorial to me.  There are six sentences in section
5 ("Testing an OWL Implementation (Informative)"); five of them are
of the form "x must y", and this last one says "x should not y".  I
didn't see any reason why it should be weaker than the others, but as
a reader the fact that it was weaker (after 5 musts) stood out.

To go against the "should" would be to go against the normative
definition of "complete", as far as I can tell, so a "must" here is
logicically redundant.  But the absense of "must" is suggestive of
some other state of affairs.

Meanwhile, I didn't notice that section 5 was only informative.  That
seems odd for a section of "musts".  Is that because this information
is all logically redundant (and its bad practice to risk conflict by
having redundant normative text) or because we specifically don't want
to say that OWL software (of the appropriate category) has to pass the
appropriate tests.  (It would be logically redundant if we said
elsewhere the tests had to be passed; a quick look does not turn up
such text, but one could read it into the fact that the tests
themselves are labeled Normative.)

(Meanwhile, I also noticed the odd lack of any category of software
related to the entailments test, but I guess it's too late in the
process to do anything about that.)

   -- sandro
Received on Monday, 12 May 2003 06:44:57 GMT

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