From: Benjamin Grosof ([email protected])
Date: 12/02/03
% notes from JC telecon 12/2/03
% by Benjamin Grosof
agenda:
- (a bit) feedback on SWRL
- (mainly) discussion of next steps and directions for SWRL;
participants:
Mike Dean
Benjamin Grosof
Harold Boley
Ian Horrocks
Peter Patel-Schneider
Deborah McGuinness
Sandro Hawke (joined late)
(regrets from Said Tabet)
%%%%
more feedback on SWRL
misc. questions raised in discussions:
- what are semantics of Datalog
- where to find the canonical definition of RuleML
%%%%
Mike and Benjamin briefly walked through possible directions
from their emails
Benj suggestions on next steps:
overall, let's start with stuff that's relatively easy and uncontroversial
as well as useful
1. sensor built-ins starting with datatype comparisons and conversions
2. n-ary predicates, which includes predicates not only
being OWL classes and predicates
- this is something the OWL and RDF efforts back-burnered
- can do pretty straightforwardly via slots
wrt n-ary:
- Mike: issue of supporting legacy n-ary stuff done in RDF
- Benj: how would they be any worse off than now, can always treat it as 2-ary
Harold and Deborah and all: let's be driven by use cases, incl. services
possible work items for future:
- look at use cases of doing n-ary, and of rules for services generally
3. more Lloyd-Topor expressiveness, e.g.,
- OR in the body -- is quite useful for practical purposes
- this is pretty straightforward as syntactic sugar -- it's reducible to Horn
- could also have existentials in the body -- particularly useful with n-ary
. maybe wait on this til we have more use cases
- could also have universals in the head
. maybe wait on this til we have more use cases
Peter: worried that there be monsters here in this territory,
since we're on top of / in combination with full DL not just within Horn,
e.g., may break some implementations' behavior that wouldn't otherwise be
broken;
e.g., or if attempt later to give an autoepistemic logic kind of semantics
(Benj: often people talk about this in terms of intuitionistic rather
than autoepistemic);
e.g., if implement in the following fashion:
query for the antecedent, then if that's satisfied,
add the consequent with appropriate bindings
-- since the DL sublanguage may contain [non-intuitionistic]
disjunctive info
Benj: if we're using a FOL semantics then it's not problematic;
your example reasoner is just of a
(potentially) incomplete reasoner being (actually) incomplete
%%%%
for next week:
Mike will present more about his suggestions on
datatype comparisons/conversions builtins
relevant paper to read for next week:
paper by Ian Horrocks et al on datatype groups
from ISWC-2003, is on Ian's webpage
________________________________________________________________________________________________
Prof. Benjamin Grosof
Web Technologies for E-Commerce, Business Policies, E-Contracting, Rules,
XML, Agents, Semantic Web Services
MIT Sloan School of Management, Information Technology group
http://ebusiness.mit.edu/bgrosof or http://www.mit.edu/~bgrosof
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