ontolog-forum
[Top] [All Lists]

Re: [ontolog-forum] Need advice

To: "[ontolog-forum]" <ontolog-forum@xxxxxxxxxxxxxxxx>, William Frank <williamf.frank@xxxxxxxxx>
From: Pat Hayes <phayes@xxxxxxx>
Date: Fri, 12 Dec 2014 23:40:09 -0600
Message-id: <EAF5C569-020A-4321-9279-337A39CAF19A@xxxxxxx>

On Dec 12, 2014, at 9:08 PM, William Frank <williamf.frank@xxxxxxxxx> wrote:    (01)

> Yup, inverse is more common in broader contexts,  from which I think that OWL 
>etc. get their usage.
> 
> For example, in traditional linquistics, tthe relations father of ad son of, 
>buyer, seller, are called 'inverse.'   This sort of follows the terminology of 
>logic, in which the inverse of 'if p then q' is i'f q then p.'     (02)

No, this is the converse. The inverse of 'if p then q' is 'if not p then not 
q'.  See 
http://hotmath.com/hotmath_help/topics/converse-inverse-contrapositive.html    (03)

But in any case, the direction of an implication, on the one hand, and the 
ordering of two arguments of a relation, on the other, really have nothing much 
to do with one another. The inverse relation of a binary relation R is (lambda 
(x,y) R(y,x)).    (04)

> similarly, in function theory, the inverse of a function from domain D to 
>range R is the other way around, the equivelent mapping back from Domain R to 
>range D, which might not be a function, of course.  
> 
> I would vote to follow these traditions and say inverse.    (05)

I agree.    (06)

> While there is always an equivelent relation in the inverse direction for a 
>function, this is something that has to be discovered, and in some languages, 
>their will only be, for some so I do not think it is a good practice to 
>dismiss the distinction as two ways of saying the very same thing.  There 
>could be interesting things about the language hidden in the fact that 
>sometimes there are two ways of saying it, sometimes only one.  And, of 
>course, sometimes there is a navigatibility build into the situation.  
> 
> 
> But both will work, because while 
> 
>  the logical converse of 'if p then q' is 'if not p then not q,' this is 
>equivelent to the inverse, 'if q then p,' so inverse and converse are 
>logically equivelent.    (07)

Indeed.    (08)

Pat Hayes    (09)


>   
> 
> 
> 
> 
> 
> On Fri, Dec 12, 2014 at 6:01 PM, Duane Nickull <duane.nickull@xxxxxxxxx> 
>wrote:
> What would be a suitable term to call a binary relationship that is 
>co-dependent yet not symmetrical to another relationship between the same 
>entity in a binary relationship?  
> 
> If "John is a father of Chris”, how can we describe that relationship in 
>terms of comparing it to “Chris is a son of John”?  Would “isomorphic”  be the 
>best term to use? “Inverse”? Assume that the relationship is traversable from 
>either side.
> 
> The context of this is in a graph database discussion group.  Graph Databases 
>have nodes and relationships.  Either can have properties.  Unlike RDBMS 
>systems, graph databases have relationships between instances of nodes, not a 
>foreign key relationship with an entire table.
> 
> The binary relationship is not symmetric since true symmetry would require 
>that the statements “..is a father of…” and “…is a son of…” be equally true 
>for A-B as they are for B-A.
> 
> Sorry for this simple request.  I am just trying to find the best description 
>for this.
> 
> Duane Nickull
> ******************************
> CTO - Hot Tomali/Cientis/Cheddar Labs
> www.hottomali.com
> 
> NOTICE: This e-mail and any attachments may contain confidential information. 
>If you are the intended recipient, please consider this a privileged 
>communication, not to be forwarded without explicit approval from the sender.  
>If you are not the intended recipient, please notify the sender immediately by 
>return e-mail, delete this e-mail and destroy any copies. Any dissemination or 
>use of this information by a person other than the intended recipient is 
>unauthorized and may be illegal. The originator reserves the right to monitor 
>all e-mail communications through its networks for quality control purposes.
> 
> 
> _________________________________________________________________
> Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
> Config Subscr: 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 join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J
>  
> 
> _________________________________________________________________
> Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/  
> Config Subscr: 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 join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J    (010)

------------------------------------------------------------
IHMC                                     (850)434 8903 home
40 South Alcaniz St.            (850)202 4416   office
Pensacola                            (850)202 4440   fax
FL 32502                              (850)291 0667   mobile (preferred)
phayes@xxxxxxx       http://www.ihmc.us/users/phayes    (011)







_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/  
Config Subscr: 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 join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J    (012)

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