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More property questions

From: ben syverson <w3@likn.org>
Date: Wed, 13 Sep 2006 18:48:08 -0500
Message-Id: <59A69941-558C-4AD5-AC5F-61D6290904E1@likn.org>
To: semantic-web@w3.org

Hi everyone,

I have another newbie questions for you. Can I infer from a property  
restriction on a Class that any individual of the Class must have the  
property in question?

That is, suppose I have a class "RedBalloon" with a restriction that  
"color" is allValuesFrom "Reds."

Does this entail that all individuals of the class RedBalloon  
implicitly have the property "color?" And does it entail that all  
these individuals have the value "Reds" for the property "color?"

I guess I ask because it could create confusion; consider the  
following. I have a class "Coffee," and add a property restriction on  
"sweetener" with the value "CoffeeSweeteners."

Does this make it impossible for an individual of Coffee to have *no*  
sweetener, or does it only restrict the types of sweeteners that can  
be applied to Coffee?

IF the property restriction only restricts the types of sweeteners,  
then is there any way to ensure that all members of a class will  
*implicitly* have a certain property? I know I can use cardinality to  
enforce that all individuals of a class *must* have a certain  
property, but is there a way to give individuals a sort of "default"  
value for a property -- or is this something left up to application  
developers?

I hope my question isn't hopelessly misguided. ;)

- ben syverson
likn.org
Received on Wednesday, 13 September 2006 23:48:22 UTC

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