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Re: Is _this_ what is meant by "Entity"?

From: Simon Miles <simon.miles@kcl.ac.uk>
Date: Sat, 3 Sep 2011 19:19:22 +0100
Message-ID: <CAKc1nHeOmCiro3RZ4haYYoF2nQhYpnqvidELmJhNZFfLkSdRtQ@mail.gmail.com>
To: Provenance Working Group WG <public-prov-wg@w3.org>
Jim,

OK, thanks. I think it's what I thought you meant :-). If we are to
get across clearly and succinctly what you describe, wouldn't it be
preferable to define entity only after process execution and
participation (both in model and primer documents)? Defining
participation requires saying what is participating, which cannot be
entities without definitions being circular, so I would assume
something like:

Defn 1. A thing is anything that can be identified. There are no
assertions directly about things in PIL, but instead about entities
(defined below).

Defn 2. A process execution is an identifiable activity, which
performs a piece of work.

Defn 3. Participation is the involvment of a thing in an activity.

Defn 4. An entity is a view on a thing defined by those
characteristics that do not vary in the process executions it is
asserted to participate in.

["executions it is asserted to participate in" may not be all
processes we want to define an entity relative to, but I can't see
what else is concrete enough to be usable.]

Defn 5. processExecution(id,rl,st,et) is an assertion that a process
execution, identified by id, occurred, and followed recipe rl
(optional) from start time st (optional) to end time et (optional).

Defn 6. entity(id, [ attr: val, ...]) is an assertion that a thing
existed and the entity defined by characteristics [ attr: val, ...],
identified by id, was a view on that thing consistent with the
participations asserted about it.

Defn 7. hasParticipant(pe, e) is an assertion that the thing on which
entity e is a view participated in process execution pe.

Are those definitions adequate to capture everything yet? They may
still be more complicated than is helpful in getting people to adopt
the standard...

Thanks,
Simon
Received on Saturday, 3 September 2011 18:46:37 GMT

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