- From: Jos De_Roo <jos.deroo.jd@belgium.agfa.com>
- Date: Mon, 20 May 2002 21:20:03 +0200
- To: pfps@research.bell-labs.com
- Cc: "www-webont-wg" <www-webont-wg@w3.org>
> My messages > http://lists.w3.org/Archives/Public/www-webont-wg/2002May/0143.html > and > http://lists.w3.org/Archives/Public/www-webont-wg/2002May/0146.html > read > > Ad/ :R a [ owl:complementOf :R ] > > on the line that you quote as > > > > > > Ad/ :R a :R > > How did that get changed in your message? I (normally) don't use my (silly) mail client to reply to messages (it can't even do > stuff) so I copy and paste in a text editor. It is indeed bizarre and I can't explain it, but it changed, I can see that. I did a lot of cut-copy-paste and it took quite some time, but I did not do that one on purpose ;-) [...] > I guess I was not clear enough. Being more explicit, the proof would > proceed along the following lines: > > | :R a :R Assumption > | :R a [ owl:complementOf :R ] From a/, using modus ponens > | FALSE From ?x a ?y, ?x a [owl:complementOf :y] -> FALSE > :R a :R -> FALSE Discharging the assumption > not(:R a :R) modus tolens I also use modus tollens (actually resolution) quite a lot inside the engine, but it's not safe I think as outside (non-closed world) evidence. -- Jos
Received on Monday, 20 May 2002 15:20:39 UTC