Minor comments on 18 Aug 2003 OWL Guide [attempt 2]

Hello,

[I just hit the send button by mistake on an incomplete
 mail....let's try again...]

I have just read most of the 18 Aug 2003 draft of 
the OWL Guide [1], which I found very readable and
helpful. I have a couple of questions on minor
editorial points.

1) Subsections of 3.4 are numbered; subsections of 3.3
   are not. I think those of 3.3 should also be
   <h3> numbered headers.

2) Under 3.3, inverseOf, "z" is mentioned in the first
   sentence (before the colon) but is not used in 
       P1(x,y) iff P2(y,x)

3) Under 3.3, inverseFuntionalProperty, on the other hand,
   "z" is not used in the first sentence but does appear
    in 
       P(y,x) and P(z,x) implies y = z.

   It looks as though the first sentences were switched...

4) The first few paragraphs of section 4 (Ontology mapping)
   seemed to cry out for at least a mention of namespaces.
   This comment is not that important, but if there is
   more information in another document about ontology
   sharing, a reference to it would be helpful.

5) I think the second example in section 5.1.2 deserves
   more explanation. Section 5.1.1 is about intersections.
   The example in 5.1.2 refers to the "intersection of
   sweet and non-sweet fruit," but the intersectionOf
   operator that was just introduced is not present. 
   I see from section 3.1.1 that "Instances of the class 
   belong to the intersection of the restrictions [that
   appear in the class definition]." That subtle point is
   lost in the wake of 5.1.1. 

   In fact, would the example in 5.1.2 be better off
   in section 5.1.1?

   Also, the example revealed to me that I do not
   understand why rdf:resource is used in some cases
   and why rdf:about is used in others. The topic
   is introduced in 3.1.1, but I don't get a good
   understanding of the difference there. The Guide says
   that rdf:about is used to "extend the definition of
   a resource." However, I don't see any extensions
   going on in the example in 5.1.2. 

Thank you,

 _ Ian
    
[1] http://www.w3.org/TR/2003/CR-owl-guide-20030818/
-- 
Ian Jacobs (ij@w3.org)   http://www.w3.org/People/Jacobs
Tel:                     +1 718 260-9447