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Is _this_ what is meant by "Entity"?

From: Graham Klyne <GK@ninebynine.org>
Date: Sat, 03 Sep 2011 07:32:59 +0100
Message-ID: <4E61CA1B.9000808@ninebynine.org>
To: Luc Moreau <L.Moreau@ecs.soton.ac.uk>, W3C provenance WG <public-prov-wg@w3.org>
Luc,

I've been reflecting on our discussion, and I think I may have got to the root 
of my misunderstanding.  To test this, I propose below an alternative phrasing 
of the definition of "Entity" - can you confirm whether or not this reflects 
what you mean:

----

An entity is an assertion about a characterized thing.  Using the Provenance 
Abstract Syntax Notation, an entity is represented as:

   entity(e,[a1:v1, a2:v2, ...])

where "e" is a name that denotes the characterized thing about which provenance 
is expressed, and the "ai:vi" are assertions about attributes of that thing. 
The entity is true exactly when all of the attribute assertions are true of the 
named thing.

For example, the entity represented by:

   entity(e0, [ type: "File", location: "/shared/crime.txt", creator: "Alice" ])

might be interpreted as asserting that the thing denoted by "e0" is a file whose 
file system location is "/shared/crime.txt", and which was created by "Alice".

----

If this correctly reflects what you mean by "entity", then I have two specific 
comments about the present text:

(1) the term "entity" is confusing when used in this way.  My interpretation and 
understanding of this word leads me to expect an entity to *be* the thing about 
which provenance is asserted, not the assertion.

(2) the phrase "An Entity represents an identifiable characterized thing" is 
confusing, in that the use of "represents" here is not the usage that I would 
expect.  Based on the above, I would say instead "An Entity represents an 
assertion about an identifiable characterized thing".

Also, if the above text reflects your intended meaning, then many of my other 
comments have their roots in this misunderstanding.

#g
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Received on Saturday, 3 September 2011 06:33:43 GMT

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