- From: Sandro Hawke <sandro@w3.org>
- Date: Fri, 01 Jun 2001 14:07:50 -0500
- To: "Jonathan Borden" <jborden@mediaone.net>, www-rdf-logic@w3.org
In message <06c801c0eab9$dcada230$0a2e249b@nemc.org> you wrote: >Sandro Hawke wrote: >> The only potential for confusion I see is that some people might want >> to jump from having a triple described (with ground facts) to assuming >> the described triple is true, but that seems clearly wrong. > >Calling something a "fact" implies that it is "true". You might try to >assert a falsehood but that would be false or inconsistent. To be consistent >you must assert a fact, i.e. the fact _must be_ true. What am I clearly >missing? I don't understand where we're not understanding each other. For example, here are 7 facts: 1. I can imagine a condition, X. 2. X can be expressed accurately as English sentence Y. 3. Y has four words. 4. The first word of Y is "the". 5. The second word of Y is "sun". 6. The third word of Y is "is". 7. The fourth word of Y is "shining". Now I'm not exactly sure which of X and Y might be best called a "condition", "state", "statement", "declartion", "sentence", "situation", etc, etc. but using only true ground facts I have essentially communicated X and Y to you without asserting them. If you take everything I say as true and I add an 8th fact: "X is true" or "X is a fact" then you are licensed to infer that the sun is shining. If instead I add an 8th fact: "X is not true" then I have made no contradiction; I have actually made a reasonable and useful statement, licensing you to infer that the sun is, in fact, not shining. Do you have any problem with this approach, beyond style? I'm sorry I haven't looked at your strawman yet, but I think it has a somewhat different syntax for facts like: 1. Statement 1 is an asserted statement that I can imagine a condition, X. 2. Statement 2 is an asserted statement that X can be expressed accurately as English sentence fact 3. 3. Statement 3 is an UNASSERTED statement that the sun is shining. The differences between these approaches seem trivial. Any formal language using the first approach can be machine translated to & from any formal language using the second approach, given a vocabulary for (1) describing the parts of a sentence and (2) asserting sentences. -- sandro
Received on Friday, 1 June 2001 14:08:01 UTC