- From: Gerd Wagner <wagnerg@tu-cottbus.de>
- Date: Thu, 7 Jul 2005 23:26:20 +0200
- To: "'Michael Kifer'" <kifer@cs.sunysb.edu>, "'Dan Connolly'" <connolly@w3.org>
- Cc: <public-rule-workshop-discuss@w3.org>
> In fact, every use of default negation *always* had a clear > scope and I am not aware of anyone who (thoughtfully) advocated > default negation and imagined otherwise. I guess Dan and others are concerned about making the scope explicit in the object language. This is indeed an option that is not supported by traditional formal LP languages (although it is supported by Prolog's metaprogramming capabilities). But you (Michael) say that FLORA-2 supports making the scope explicit, right? Maybe you can give us an example how this looks like in FLORA-2 and what it means in the underlying formal semantics? > Finally, I would like to say once again that the term > "negation as failure" is bad and misleading. > Traditionally, negation as failure meant the > particular strategy used in Prolog. NAF is just one > of the known forms of default negation. Why should the term "default negation" be better and less misleading than the term "negation as failure"? I think the latter says more about the meaning of NAF than the former. -Gerd
Received on Thursday, 7 July 2005 21:27:21 UTC