ontolog-forum
[Top] [All Lists]

Re: [ontolog-forum] Question: more on N-ary?

To: "[ontolog-forum] " <ontolog-forum@xxxxxxxxxxxxxxxx>
From: Chris Menzel <cmenzel@xxxxxxxx>
Date: Fri, 15 Jul 2005 19:58:29 -0500
Message-id: <20050716005829.GI903@xxxxxxxx>
On Thu, Jul 14, 2005 at 06:43:09PM -0500, Chris Menzel wrote:
> ...
> Symmetry and coreflexivity are properties of binary relations.  A binary
> relation R is symmetric just in case, whenever it holds of the pair
> (a,b) it also holds of (b,a); formally:
> 
> (<=> (Symmetric R)
>      (forall (?x ?y)
>              (=> (R a b)
>                  (R b a))))
> ...
> A relation is coreflexive just in case it holds of (a,b) only if a is
> identical to b:
> 
> (<=> (Coreflexive R)
>      (forall (?x ?y)
>              (=> (R a b)
>                  (= a b))))    (01)

Doh!  A couple of careless typos there:    (02)

(<=> (Symmetric R)
     (forall (?x ?y)
             (=> (R ?x ?y)
                 (R ?y ?x))))    (03)

(<=> (Coreflexive R)
     (forall (?x ?y)
             (=> (R ?x ?y)
                 (= ?x ?y))))    (04)

Chris Menzel    (05)

_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
Subscribe/Unsubscribe/Config: 
http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/ 
To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx    (06)

<Prev in Thread] Current Thread [Next in Thread>