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Re: SWC review part 4 (final part) - (Re: RDF and owl compatibility document ready to be frozen)

From: Jos de Bruijn <debruijn@inf.unibz.it>
Date: Thu, 10 Jul 2008 10:46:42 +0200
Message-ID: <4875CC72.10208@inf.unibz.it>
To: Axel Polleres <axel.polleres@deri.org>
CC: Sandro Hawke <sandro@w3.org>, public-rif-wg@w3.org
Axel,

Thanks for your comments.
I think the changes prompted by the comments fall in the category of 
"fixing obvious errors", and so can still be considered for last call. 
There were one (English) grammatical error, two notational errors 
(Datatype versus DATATYPE and the repetition in the definition of I* in 
the proof), and two small technical errors (meta-variables and the 
reference to the wrong column in the table).

> Section 8.2.3.2
> 
> *) "In the following, let T be the set of considered datatypes union the 
> set of datatypes used in any ontology under consideration."
> 
> this reads badly, better.. the word "union" is used as in a mathematical 
> formula in natural language text, better write:
> 
> "In the following, let T be the union of the set of considered datatypes 
> with the set of datatypes used in any ontology under consideration.

ok

> 
> *) you use: pred:isDatatype. but pred:isNotDATATYPE ... capitalization!

ok

> 
> *) Table embedding OWL DLP, row 10 onwards. You use two explicit 
> variables ?x and ?y ... this doesn't work recursively, you need 
> metavariables!

You are right that in some cases we need meta-variables, but not 
everywhere.  Namely, in the translation of subclass statements we can 
simply introduce a new variable, because the statement is translated to 
a new rule.

> 
> i.e. change:
> 
> row 10, column 2: "trO(description1,description2,?x)"
> 
> to trO(description1,description2, ?<i>x<sub>new</sub></i>)
> 
> and add a to the condition column the remark:
> 
> "where <i>x<sub>new</sub> is a "fresh" variable name not used anywhere 
> else in the translation so far."

This is not necessary, because the statement is translated to a new rule.

> 
> analogously, in row 11:
> 
> instead of "?x" write "?<i>x<i>"
> 
> and add to the condition column: <i>x<i> is a variable name.

Yes, here it is necessary.

> 
> row 12, 13, 14,15, 16:
> 
> again, you need a metavariable for x.

In 12 and 13 it is not necessary, but in the other rows it is

By the way, I realize now that it probably makes sense to move down the 
row 11 to below what is now a row 13 (it reads more natural) , but this 
should be done after last call.

> 
> row 16:
> 
>   tr<sub>O</sub>(value<sub>i</sub>)
> should be
>   tr(value<sub>i</sub>)
> or no?

yes

> 
> row 17:
>  again meta-variable for ?x .. otherwise, i.e. if you don't use 
> meta-variables, the other rules don't apply for
>   tr<sub>O</sub>(description, ?y)
> you want rows 11-17 also apply recursively to ?y, or no?

   12 and 13, no, the others, yes

> 
> 
> *) In the proof of the Normalized Combination Embedding Lemma, this 
> looks strange to me:
> 
> "
> I* = <TV, DTS, D*, D*ind union (union of the value spaces of all 
> datatypes in the range of D), Dfunc, IC, IV, IF, Iframe', ISF, Isub, 
> Iisa, I=, Iexternal, Itruth> is such that
> 
>     * D*ind=Dind union (union of the value spaces of all datatypes in 
> the range of D) and
>     * D*=D union D*ind
> "
> 
> if "D*ind=Dind union (union of the value spaces of all datatypes in the 
> range of D)" then why do you define in I*
> "D*ind union (union of the value spaces of all datatypes in the range of 
> D)"
> this is superfluous, it seeems you can just write:
> 
> "I* = <TV, DTS, D*, D*ind, Dfunc, IC, IV, IF, Iframe', ISF, Isub, Iisa, 
> I=, Iexternal, Itruth> is such that [...]"

yes

> 
> *) Also in the proof further down, you talk about:
> "(cf. the right column of Table Normalizing OWL DLP)"
> This table has three, columns... you don't mean the right (condition) 
> column, but the second (middle) column here, I strongly assume.

yes

> 
> Apart from that, all looks quite like an argument with a red line in the 
> proof to me, although I didn't check back in detail with the OWL 
> semantics here, I trust you.

thanks for your confidence :-)


Jos

-- 
                          debruijn@inf.unibz.it

Jos de Bruijn,        http://www.debruijn.net/
----------------------------------------------
One man that has a mind and knows it can
always beat ten men who haven't and don't.
   -- George Bernard Shaw


Received on Thursday, 10 July 2008 08:47:29 GMT

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