- From: Steve Pepper <pepper@ontopia.net>
- Date: Fri, 24 Mar 2006 12:59:21 +0100
- To: "Pat Hayes" <phayes@ihmc.us>
- Cc: "SWBPD list" <public-swbp-wg@w3.org>
Hi Pat, Your intervention in this discussion is much appreciated. | >[Regarding the issue of whether reification has the same | >semantics in Topic Maps and RDF] | | Sorry, I have only just seen this thread. This reply doesn't attempt to answer all your questions: others are better qualified to do that. But a couple of comments might help the discussion along. 1. The basic fact that Bill and Sue are married (your #2) can be represented in TMs as a typed binary association between what TMs term the two "subjects" Bill and Sue who play the roles of husband and wife. Thus (in LTM notation, which is hopefully self-explanatory): married-to( bill : husband, sue : wife ) This association can be reified such that the relationship it represents itself becomes a subject which can play roles in further relationships: married-to( bill : husband, sue : wife ) ~marriage-of-bill-and-sue Thus it is possible (in TMs) to state that (A) Bill and Sue are married and that (B) their marriage dates from a certain date, as two separate associations and yet still know that we are talking about the same "thing" (the relationship, in the common use sense of the word): (A) married-to( bill : husband, sue : wife ) ~marriage-of-bill-and-sue (B) {marriage-of-bill-and-sue, start-date, [[2005-08-20]]} Note: (B) is here expressed as an occurrence since the date is represented as a string rather than a topic. | Then we can distinguish | | 2. The fact that Bill and Sue are married | 3. The particular state of being married that | holds uniquely between Bill and Sue (and no | others) 2. As Lars Marius pointed out, it is hard to see the difference between these two from the Topic Maps point of view. Perhaps this is precisely because Topic Maps is NOT based on logic, but rather seeks to model a fuzzier and more natural language oriented view of the world? Steve -- Steve Pepper <pepper@ontopia.net> Coordinator, W3C RDF/TM Task Force
Received on Friday, 24 March 2006 11:59:30 UTC