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RE: "If" and "else" in RDF

From: Steven Livingstone <stv_ca@hotmail.com>
Date: Sun, 29 Apr 2001 10:22:03 -0500
To: danny@panlanka.net, altheim@eng.sun.com
Cc: www-rdf-interest@w3.org
Message-ID: <F23434ryRHXYOactwga0000b066@hotmail.com>
After getting confused myself, i thought about how RDF works with "if then 
else" statements. Tell me if i am wrong somewhere, but, i think JT's email 
at the start of this sums it all up pretty much.

To me there is no real "if then" type statements in RDF (in this sense 
anyway), rather they are implicit in the definition. For example, i don't 
think of a procedural statement

If z(Male) then "Mr" else "Ms"

I just think of the rule z(Male) and this implies that "Mr" is used because 
the schema defines that the Male class has certain sub-properties and 
sub-classes of which one is the "Mr" definition. If the same way, z(Female) 
would do the same.

<rdfs:Class id="Gender" rdfs:label="Gender"/>
<rdf:Property id="address" rdfs:domain="#Gender"
rdfs:range="http://www.w3.org/2000/01/rdf-schema#Literal"/>

<Gender id="Male">
   <rdfs:label>Male</rdfs:label>
   <address>Mr</address>
</Gender>

<Gender id="Female">
   <rdfs:label>Female</rdfs:label>
   <address>Ms</address>
</Gender>

To me the relationship is implicit in the definition, no "if then" is really 
needed.

I dunno if this helps in any way, but it did me.

cheers,
steven


>From: "Danny Ayers" <danny@panlanka.net>
>To: "Murray Altheim" <altheim@eng.sun.com>
>CC: <www-rdf-interest@w3.org>
>Subject: RE: "If" and "else" in RDF
>Date: Sun, 29 Apr 2001 18:13:19 +0600
>
>
><- You have guys have me really confused. Are you trying to find a way to
><- express a material implication relationship, or perform a programmatic
><- function? Turn RDF into a programming language? I don't get it.
><- Expressing
><- relationships is one thing, actually acting on them is a whole different
><- bahoosus.
>
>
>I think the confusion stems from the fact that 'if' and 'then' (/'else') 
>are
>commonly used in both declarative and imperative computer languages. In the
>declarative context if...then... goes right back to the basic connectives 
>of
>propositional logic, where one can say if <something> then <something
>else> - a relationship is stated, there is no processing involved. RDF is a
>declarative language (a representation language, whether or not you call it
>a programming language is probably irrelevant), so surely this is the
>appropriate context here.
>

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Received on Sunday, 29 April 2001 11:22:13 GMT

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