Outcomes from 12/19 telecon

The telecon discussion went on quite long today and we didn't have 
time for everything on the agenda.  I felt like we were near 
resolution on a few issues but didn't quite get there, so I'd like to 
summarize where I think we are. Overall I'm quite happy to see that we 
are finally starting to deal with concrete technical issues.

Hassan proposed at the f2f to use constraints as a way to connect a 
keyword syntax with a positional syntax, by mapping positional syntax 
into keyword syntax.  Harold later found that the specific syntax 
proposed by Hassan created a problem with unifying variable arity 
predicates, that is that (P x y) would unify with (P x), and Harold 
proposed a solution that maps keyword syntax into positional.  A few 
of us were unsure on the telecon today that the proposal as it stood 
(using 'bottom' to substitute for missing parameters) would work, as 
bottom unifies with nothing, which would create unexpected results 
compared to keyword systems. Hassan suggested that keeping the mapping 
of positional onto keyword would work if we also introduced function 
signatures, which could prevent unifying a binary predicate with a 
unary one when it mattered.  Harold has not weighed in on that counter 
proposal yet.

Michael expressed some concern that the CLP formulation would not 
handle model theories for WFS. (was that right?)  Hassan was unsure 
and will try to find the answer.

We discussed for a while the idea of treating constraints as an 
"external call".  This seemed to concern several of us, but I think 
the confusion was cleared up as just overloading of "external call" - 
here the idea is that constraints as part of RIF rules allows RIF to 
treat data models and languages as orthogonal.



-- 
Dr. Christopher A. Welty                    IBM Watson Research Center
+1.914.784.7055                             19 Skyline Dr.
cawelty@gmail.com                           Hawthorne, NY 10532
http://www.research.ibm.com/people/w/welty

Received on Wednesday, 20 December 2006 02:36:45 UTC