RE: PROV-ISSUE-8: defining generation in terms of `IVPT of'

This would mean that a heating process modifies an egg to create a warm egg, it does not transform a cold egg into a warm egg? 
Or do you mean both - a process execution can turn one thing into another, these things can be considered IVPTs of a thing that participates in the process execution/ is modified by the process execution? And in an open world assumption, a witness doesn't have to report the modified thing or can decline to identify/report either of things in IVPT roles depending on their ability to observe and the use case they wish to enable?


From: on behalf of Luc Moreau
Sent: Thu 6/9/2011 6:44 PM
To: Provenance Working Group WG
Subject: PROV-ISSUE-8: defining generation in terms of `IVPT of'

Hi all,

- if a new thing is created, it is clear that we have a new IVPT of that thing
if a chicken creates an egg is it just an IVPT of an egg?

- if the thing is modified, then it is a requirement that a new view (IVPT) is generated ...
       otherwise, it would still be a view that existed before
can't I say the egg was heated without reporting its cold and warm states? I.e. don't we want to be able to report that something was modified without having to report the IVPTs? A document was edited four times by different people but I don't wan't to/can't tell you what each wrote at each stage?

- if the process execution was taking a long time to modify/create the thing, there is only one
   instant at which the (invariant!) IVPT appears
I thnk we could define it that way, but if a cracking process takes time, saying the cracked egg appears instantaneously basically means you want 'cracked egg' to be defined by some threshold - the cracked egg might become more cracked over time ) invariant only in that it is always above the threshold and the instance of the creation of the IVPT relationship occurs ata  aspecific instant.

- I think this captures well a stateful objects, where processes can modify the object, resulting in
   different IVPTs corresponding to the various states

IVPTs are not a separate kind of thing and their invariance is relative. If they are truly immutable sates/snapshopts, they can only exist for an instant because some part of the state of the thing (a part we may not care about such as age) will change immediately.

What do you think?


Received on Friday, 10 June 2011 01:29:32 UTC