- From: Graham Klyne <GK@NineByNine.org>
- Date: Wed, 05 Sep 2001 15:21:31 +0100
- To: Pat Hayes <phayes@ai.uwf.edu>
- Cc: RDF core WG <w3c-rdfcore-wg@w3.org>
Some comments on the 28-Aug MT draft. I think this is great, and highly
edifying. My comments mostly point up areas I was struggling to understand
what was being said...
--
Secetion 0/general.
The Qname prefixes rdf and rdfs are used extensively. For completeness,
the corresponding URIs should probably be noted somewhere; e.g. in section 0:
[[[
This memo uses the QName syntax to refer to certain URIs defined by
RDF. The following namespace prefix and URI values are assumed throughout:
Prefix: rdf, namespace URI: http://...
Prefix: rdfs, namespace URI: http://...
]]]
--
Section 1.
Although it becomes fairly clear on careful reading, it wasn't immediately
obvious to me that this section did not deal with anon nodes. Maybe a 1st
sentence:
[[[
This section describes the interpretation of ground RDF graphs.
]]]
This section seemed to introduce symbols and notation without always
clearly indicating what they were intended to denote:
I
vocab(I)
<s p o>
5th para: I take it the discussion of time-varying referents is not
intended to preclude resources with time-varying attributes? (E.g. a
vehicle whose current position can be a function of time.)
Introduction of E and I(E): "... RDF graph E in I ..." took several
attempts to grok because I kept reading the "in" as set inclusion; maybe
"according to" or "under"? Also, I found the description of E as an RDF
graph to be slightly confusing, because some of the interpretations given
were for things that I don't understand to be graphs: <qLiteral>, <uriref>.
Denotation of I(E): missing bracket I(s) in
if E is an asserted triple with the form <s p o>
then I(E) = true iff <I(s),I(o)> is in IEXT(I(p))...
(Isn't the 'iff' overkill here, in the presence of the otherwise clause?)
--
Section 2.
The meaning of B in "for some value of B defined on anon(E)" was not
immediately clear to me. I think you mean something like "for some mapping
B from anon(E) to the domain of I".
Paragraph discussing treatment of anon nodes as existentially
quantified. "... there is no need to specify the scope of the quantifier
within a graph." Should that be "quantification"? (I understand
"quantifier" to be a variable name used to denote quantification.)
Next para: I struggled with this; "the same interpretation ... also
assigns truth values to graphs with anonymous nodes", etc. I don't see how
this works. The Interpretation defined for ground graphs seems to depend
on having a direct model theoretic interpretation for the nodes mentioned
(if E is <s p o>, I(E) = true iff <I(s),I(o)> is in IEXT(I(p))... )
--
Section 3.
When you say:
I(rdfs:ConstraintResource) is in IC
do you mean ... is in IR?
The next condition is well-mangled by my browser; is that the intersection
of "ICEXT(I(rdfs:ConstraintResource)) and IP" ?
--
That's all for now.
#g
------------
Graham Klyne
(GK@ACM.ORG)
Received on Wednesday, 5 September 2001 10:25:46 UTC