Problems with Onntolingua, on-line KSL Services

"Joaquin.A.Delgado" <>
Date: Tue, 25 Jul 95 17:21:26 JST
From: "Joaquin.A.Delgado" <>
Message-id: <>
Subject: Problems with Onntolingua, on-line KSL Services

 I've had serious problems when trying to define an axiom of 
 a unary relation over a class. 
 First, Ontoligua treats a unary relation over a class as a
 sub-class of the former class, although the internal representation
 is indeed a relation. This is semanticly OK, but it has brought me 
 troubles with Ontoligua's internal representations, while defining 
 it's axioms since  Ontolingua won't let me. 
 It gives the following error:

You are attempting to redefine #%Ol-User::A@My-Ontology as an 
ONTOLINGUA:ONTO-CLASS. It is currently already defined as an 
ONTOLINGUA:ONTO-CLASS, but of a different concrete implementation type. 
This redefinition cannot be performed. You should either delete 
the existing definition, rename this definition, or shadow the 
word ONTOLINGUA-USER::A in ontology ONTOLINGUA-USER::My-Ontology

Where A is a unary relation with class X as domain (Treated as
sub-class by Ontolingua) and I whish to define an axiom of A such

  (=> (A ?X) 

 This does no happens when defining n-ary relations (other than unary)
 and it also works when defining an axiom of a Class (a normal class
 or sub-class).

 If any one can help I'll be very much appreciated!

Joaquin Delgado   e-mail:
ATR Research Labs, JAPAN