- From: Brian McBride <bwm@hplb.hpl.hp.com>
- Date: Mon, 17 Sep 2001 18:24:43 +0100
- To: Pat Hayes <phayes@ai.uwf.edu>
- CC: w3c-rdfcore-wg@w3.org
Pat Hayes wrote:
> Well, oddly enough, I did once do some work on three-valued logics, and
> was thinking about that when commenting on the f*s. But I now think
> that what that "truth-table" is about is syntactic identity, not
> equality (ie same referent).
I so love that whooshing sound as something passes completely over
my head :(
I'm not sure what is meant by syntactic identity, and I'm not sure
why I should care about it.
The truth table shows (s,_)=(s,t) as f*. The character strings
"(s,_)" and "(s,t)" are clearly different, so that can't be what
is meant by syntactic identity.
If (s,_) could be equal to (s,t), then presumably it could also
be equal to (s,w) where w != t. Does that mean we can conclude
that (s,w)=(s,t) - not according to the truth table. Are we
be dealing with an '=' operator which is not transitive? Maybe
(s,_) can equal (s,t) or (s,w) but not both at the same time.
Does (s,_) denote exists(x): (s,x) ?
In my naive view of the world, the literal denoted by
("foo", "http:/lang/en") is not equal to ("foo", _), just the same as
the pair (1,2) is not equal to (1,3).
What is the value in making this any more complicated?
I'm expecting when some a bunch of rdf/xml or n-triples is read that
we can be definitive about the number of unique triples in the graph
that results. It worries met that f* will cause me to lose that
property.
I think I'm just confused.
Brian
Received on Monday, 17 September 2001 13:28:42 UTC