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OWL-S: simple proposal to evolve logic expressions

From: David Martin <martin@AI.SRI.COM>
Date: Wed, 18 May 2005 23:18:20 -0700
Message-ID: <428C2FAC.7060802@ai.sri.com>
To: public-sws-ig <public-sws-ig@w3.org>

Here is a simple proposal for evolution of logic expressions used in 
OWL-S (see
These changes would appear in release 1.2.

This is to allow for unquoted SWRL and DRS expressions, and also to add 
some new categories of expression (SWRL-FOL, RDQL and SPARQL), as 
discussed in recent telecons and private messages.

OWL-S folks (and interested parties), please review and comment if needed.

--- Background

Currently we have class Expression with subclasses
     SWRL-Expression, DRS-Expression, KIF-Expression

Expression has DatatypeProperty expressionBody (the values of which are 
the actual "quoted" expressions), with range restrictions:
   for SWRL-Expression range = XMLLiteral
   for DRS-Expression range = XMLLiteral
   (not restricted for KIF-Expression, but understood to be a string)

--- Proposed change (1):

Add new subclasses of Expression:
     SPARQL-Expression, RDQL-Expression, and SWRL-FOL-Expression

--- Proposed change (2):

Add a new property of Expression:
   ObjectProperty expressionContent (for "unquoted" expressions)

expressionContent will be used with SWRL-Expression and DRS-Expression

expressionBody will be used with KIF-Expression, SPARQL-Expression, 
RDQL-Expression, and SWRL-FOL-Expression

--- Proposed change (3):

Mandate the above conventions with cardinality restrictions:

Specify cardinality = 0 on expressionBody and cardinality = 1 on 
expressionContent on SWRL-Expression and DRS-Expression

Specify cardinality = 1 on expressionBody and cardinality = 0 on 
expressionContent on KIF-Expression, SPARQL-Expression, RDQL-Expression, 
and SWRL-FOL-Expression

--- Proposed change (4):

Restrict range of expressionContent:
   for SWRL-Expression range = union of Imp, AtomList, and Atom
   for DRS-Expression range = <whatever Drew says>

Received on Thursday, 19 May 2005 06:18:52 UTC

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