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Re: [ontolog-forum] Re: The issue of Context

To: cassidy@xxxxxxxxx
Cc: ontolog-forum@xxxxxxxxxxxxxxxx
From: Adam Pease <adampease@xxxxxxxxxxxxx>
Date: Wed, 25 Feb 2004 08:55:40 -0800
Message-id: <5.0.0.25.0.20040225082743.01c9cdc0@xxxxxxxxxxxxxxxxxx>
Pat,
   Interesting.  You're at least partially correct that adding a new sister 
concept for Abstract and Physical would not yield a contradiction.  We have 
axioms that say    (01)

1.  a partition implies an "exhaustive decomposition" and a "disjoint 
decomposition"    (02)

   (<=>
     (partition @ROW)
     (and
         (exhaustiveDecomposition @ROW)
         (disjointDecomposition @ROW)))    (03)

2.  an exhaustive decomposition of ?CLASS implies that if another term is 
an instance of ?CLASS, that it must be an instance of one of the classes in 
the decomposition    (04)

  (=>
     (exhaustiveDecomposition ?CLASS @ROW)
     (forall (?OBJ)
         (=>
             (instance ?OBJ ?CLASS)
             (exists (?ITEM)
                 (and
                     (inList ?ITEM
                         (ListFn @ROW))
                     (instance ?OBJ ?ITEM))))))    (05)

This axiom is important, since it says that even if you create a sister 
class, such as Context, to the items in the partition in question, any 
instances will still be instances of Abstract or Physical, although you are 
allowed to define them as instances of Context as well.  To prevent this 
rather perverse case, we should probably add an axiom    (06)

   (=>
     (exhaustiveDecomposition ?CLASS @ROW)
     (not
       (exists (?NEWCLASS)
         (and
           (immediateSubclass ?NEWCLASS ?CLASS)
           (not
             (inList ?NEWCLASS
               (ListFn @ROW)))))))    (07)

This axiom would say that    (08)

- an exhaustive decomposition of ?CLASS implies that there is not some 
other class that is an immediate subclass of ?CLASS other than that given 
in the list    (09)

This axiom would be a welcome and constructive addition to SUMO.  Thanks 
for helping me figure it out.    (010)

Adam    (011)

At 05:29 AM 2/25/2004 -0500, Patrick Cassidy wrote:    (012)


>Adam Pease wrote:
>
>>>   I also agree with Adam that "physical" and "abstract" are
>>>intended to be exhaustive under "entity" as represented in
>>>SUMO now.  And I have no problem with the notion that
>>>every *instance* of an entity would be either Abstract
>>>or Physical. However, I cannot find any **axioms** in my
>>>copy of SUMO 1.566 which state that there cannot be any
>>>direct subclasses of "Entity" other than "Abstract"
>>>or "Physical".
>>
>>The statement is
>>(partition Entity Physical Abstract)
>>at line 734.  You may need to refer to the axioms which define &%partition
>>Adam
>    Adam, I have read the axioms and they do not forbid the
>existence of additional sister classes to Abstract and
>Physical.
>    Could you be more specific about which axiom you think
>forbids such a class, and show the logic that makes
>such a class inconsistent with the axiom?  I have worked
>through the axioms I have in SUMO 1.56 and I do not see
>that implication.
>
>     Pat
>
>--
>=============================================
>Patrick Cassidy
>
>MICRA, Inc.                      || (908) 561-3416
>735 Belvidere Ave.               || (908) 668-5252 (if no answer)
>Plainfield, NJ 07062-2054        || (908) 668-5904 (fax)
>
>internet:   cassidy@xxxxxxxxx
>=============================================    (013)

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