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RE: Deduced property

From: エリクソン トーレ <t-eriksson@so.taisho.co.jp>
Date: Sun, 2 Feb 2014 23:22:41 +0000
To: "tim.glover@bt.com" <tim.glover@bt.com>
CC: "semantic-web@w3.org" <semantic-web@w3.org>
Message-ID: <B8B61EF2E200BD439D622523ECDB9D23FD59A1E5@bpxm02ts.taishogroup.local>
> From: tim.glover@bt.com, February 01, 2014 1:21 AM
> As a software engineer, the striking difference is this.  In Java, if a class
> A  has property x, then all objects of that class have property x. If class
> B extends A, then all objects of class B also have property x.
> 
> In OWL the logical direction  is completely different. In OWL, if property
> x has domain A, that does NOT mean that all objects of class A have property
> x. It means that IF an object has property x, it must belong to class A (very
> roughly speaking -  I am aiming for conceptual intuition of the difference
> here, rather than strict accuracy). IF B is a subclass of A, and IF I can
> deduce that object b is a B, then it must also be an A.

A good explanation for software engineers might be that OWL does strong duck typing.
Strong in the sense that the classes of an instance are defined by its properties.
Then they can probably extrapolate any consequences of this and arrive at OWL logic.

Tore
Received on Sunday, 2 February 2014 23:23:39 UTC

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