- From: Jim Farrugia <jim@spatial.maine.edu>
- Date: Tue, 20 Aug 2002 10:49:52 -0400 (EDT)
- To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
- cc: www-rdf-logic@w3.org
Peter, Some brief comments below. Thanks for your detailed replies. Jim [...] > > JF: OK, let's see.... > > > > > > 1) what is the right way to get at the question whether the DAML+OIL > > axiomatic semantics "gives us the same thing" as the DAML+OIL > > model-theoretic semantics? Does it make sense to try to ask such > > a question, or is it a case of apples and oranges? > > This is a valid question. To be more precise, the kind of question that > you can ask is, given the axiomatization, A, and two DAML+OIL KBs, K and Q, > whether > K entails Q in the model theory > iff > K + A entails Q in the model theory of the logic underlying the > axiomatization > > One can also ask an equivalent question, namely whether > K entails Q in the model theory > iff > Q can be derived from K + A in a sound and complete proof theory > for the logic underlying the axiomatization > > Unfortunately, the answer to this question is no. The fact that the answer is no seems like not a good thing, though it seems it may be a fact of life. ?? To what can this fact be attributed - properties of the DAML+OIL axiomatization? Properties of the logic underlying the axiomatization (which is what, by the way?)? Something else? How do DAML+OIL people respond to or deal with this fact, which seems to say that one can't be sure that the axiomatic semantics for DAML+OIL "give the same thing" as the model-theoretic semantics? The reason I ask is that an implementer without much logical background might suppose that since two well-defined semantics are provided for DAML+OIL, they do in fact "give the same thing" as far as meanings and inferences are concerned. Thanks, Jim
Received on Tuesday, 20 August 2002 10:57:33 UTC