Re: [ontolog-forum] Scheduling a Discussion [was: CL, CG, IKL and the re

[Pat Hayes <phayes@xxxxxxx>]

At 8:27 AM -0500 1/18/08, John Black wrote:

> (disputing
> myself)
>  
> on Thur. Jan. 17, 2008,
> at 11:38, John Black wrote:
>  
> JB>In other words, my
> intuition says that in this case: (ist today (and A (not A))), today
> is not a valid context for that tautology because there is no other
> context, which if it took the place of "today", would change
> the value of that tautology.
>  
> I just realized that if A
> = "(President JimmyCarter)" and the time interval was
> 'time-interval:1950-2000' then A would in fact be both true and false
> within that interval - just at different times points or intervals
> within that interval.

Yes....

>  In other
> words:
>  
>     (ist
> time-interval:1950-2000 (and (President JimmyCarter) (not (President
> JimmyCarter)))).

...nope. You have to be more careful. (and A (not A)) is never true. Its false when A is true and its false when A is false. What you mean is that there are (at least) two parts of the context 1950-2000, and A is true in one of them and false in the other. Now you are doing context mereology (theory of parts). Using the notation from my 'note', it comes out like this:

(exists (C D)(and

        (C < 1950-2000)

        (D < 1950-2000)

        (ist C (President JimmyCarter))

        (ist D (not (President Jimmycarter)))

))

>  
> So today is is a
> "valid context" (if there is such a thing) since there are
> other intervals that make that proposition true.
>  
> I'm going back to more
> reading and thinking.....
>  
> John
>  
>  
>  
>  
>  
> _________________________________________________________________
> Message Archives:
> http://ontolog.cim3.net/forum/ontolog-forum/ 
> Subscribe/Config:
> http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/ 
> Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
> Shared Files: http://ontolog.cim3.net/file/
> Community Wiki: http://ontolog.cim3.net/wiki/
> To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx
>

-- 

---------------------------------------------------------------------
IHMC               (850)434 8903 or (650)494 3973   home
40 South Alcaniz St.       (850)202 4416   office
Pensacola                 (850)202 4440   fax
FL 32502                     (850)291 0667    cell
phayesAT-SIGNihmc.us       http://www.ihmc.us/users/phayes

_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/  
Subscribe/Config: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/  
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/ 
To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx    (01)