- From: Pat Hayes <phayes@ai.uwf.edu>
- Date: Mon, 1 Apr 2002 19:52:52 -0600
- To: "Jeremy Carroll" <jjc@hplb.hpl.hp.com>
- Cc: www-webont-wg@w3.org
>A small clarification, and then a more detailed reply. >Entailment & Logic >================== > >> Jeremy Carroll wrote: >> > What are the use cases for this ability? >> >> Basically anywhere you see (in N3) { ... } a context is defined >> in which the >> contents are not necessarily asserted. >> >> Perhaps the simplest use of this is an IF THEN statement or an OR >> statement >> >> IF {sky color blue} THEN {trees color green} >[..snip..] >> A simple way to write down a simple formula is the use case. > >My problem with this is whether the examples are in scope. > >I am in this group to help provide a language to specify ontologies for data >and information on the web. > >N3 and the examples appear to be trying the rather more ambitious task of >having a web language for writing complex logical expressions. A worthwhile >task, but not my understanding of our task. Jeremy, perhaps you could clarify the distinction you have in mind here between 'data and information' on the one hand and 'complex logical expressions' on the other. I take it that you have in mind that the former does not require the latter, since it can be done using only 'simpler' logical expressions. Can you give, if only approximately, some idea of where you think the line should be drawn between the simple and the complex here? >I believe that we will need to talk about logical entailment. (In order for >us to discuss and specify the meaning of OWL). > >I do not believe that we will need logical entailment in our language. If we have negation and disjunction then we are perilously close to having logical implication. And why not? Its very handy, three-year-old kids can understand it, and its almost impossible to specify ontologies without it in some form or another. Why are we going through such torture to avoid it? Pat -- --------------------------------------------------------------------- IHMC (850)434 8903 home 40 South Alcaniz St. (850)202 4416 office Pensacola, FL 32501 (850)202 4440 fax phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
Received on Monday, 1 April 2002 20:52:55 UTC