- From: Matt Halstead <matt.halstead@auckland.ac.nz>
- Date: Tue, 20 Apr 2004 17:05:30 +1200
- To: Stephen Rhoads <rhoadsnyc@mac.com>
- Cc: www-rdf-logic@w3.org
Necessary are conditions that must be met by and individual of a particular class, e.g. a Man must have the property of being human, but being human does not imply being a man. With necessary and sufficient we have conditions that are both necessary, as in above, but then also sufficient for indicating inclusion in the extension of some class. E.g. a Man must have the property of being human and being male, we can use the intersection of human and male to form a necessary and sufficient condition, such that any individual that is male and human can be classified as a Man. One trick is to think about having a large group of individuals exhibiting values for properties you find in various classes in your ontology. You have no idea what they may represent, so you can at least start by going through and checking all necessary and sufficient conditions of classes against individuals to see if they classify as one or more of those classes. cheers Matt On 20/04/2004, at 9:22 AM, Stephen Rhoads wrote: > > I would appreciate it greatly if someone could explain to me what the > difference is between a Necessary condition and a Necessary & > Sufficient condition. > > I would gladly RTFM if only I could find one. > > --- Stephen >
Received on Tuesday, 20 April 2004 01:07:28 UTC