- From: Michael Kifer <kifer@cs.sunysb.edu>
- Date: Tue, 15 Apr 2008 14:45:12 -0400
- To: Christian de Sainte Marie <csma@ilog.fr>
- Cc: "Boley, Harold" <Harold.Boley@nrc-cnrc.gc.ca>, RIF WG <public-rif-wg@w3.org>
If you mean that =, #, ## with external terms should be allowed to appear in the rule bodies then yes, they should. I thought you wanted to assert equalities among the externals. I agree that BLD makes contradictory statements about them. Actually, I found a number of other problems with the syntax. For instance, atomic external formulas were not well-defined. I made the required changes now (incl. fixing the contradictions about external terms, which you noticed). If Sandro could stealthily replace the published version -- would be good. Not a very big deal though. --michael > Michael Kifer wrote: > >> > >>No, I meant: in "# Equality terms. If t and s are simple, positional, or > >>named-argument terms then t = s is an equality term.", shouldn't t and s > >>be allowed to be external terms as well (same for #, ## and frame)? > >> > > I think that equality among external terms should *not* be allowed, since > > it cannot be tested anyway (definition of an external term is a black box > > to a rif document, by definition). > > It can be tested by the consumer: if it could not, a RIF document that > contained external calls would be useless, wouldn't it? > > > For instance, one could write External(t) = External(s) > > but these two externals' black boxes might not be equal, and the reasoner > > will have no way of testing that. > > I can see that equality or classification terms with external terms may > be a problem in the head; but in the body? > > Christian > >
Received on Tuesday, 15 April 2008 18:45:47 UTC