Re: Definitions and provenance and invariance

Paul - As I understood the intent, the provenance of a thing would be
assertions about the invariant properties of that thing, yes. You
couldn't say much about the variant properties other than that they're
variant. However, it may be unnecessary to explicitly "declare"
properties to be invariant.

Paolo - I agree that we shouldn't mix up fixed assertions on the
values of properties with those properties being invariant. Though I
don't think anyone has suggested the former - even if properties were
declared to be invariant (as I think Paul's question implied), that
would not be the same as declaring what their values were, let alone
not allowing those declarations to change.


On 26 June 2011 12:12, Paolo Missier <> wrote:
> I would say you can talk about the provenance of that view. But, to be clear, the fact that some properties are "declared" to be
> fixed (constant), for example by saying that "the creator is {invariant, immutable, constant,...}",  should have nothing to do with
> provenance.  It's in the semantics of the "thing" and its properties, I hope we agree on this? In a data model, one would enforce a
> constraint to avoid "creator" being updated, to reflect the intended semantics of the property. Is this what we mean by "fixed"?
> And even then, that's assuming too much already: updates to "creator" may be acceptable if the original value is found to be wrong,
> for example.
> -Paolo
> On 6/26/11 9:56 AM, Pgroth wrote:
>> For my clarification, once an asseter  has an invariant view of some stuff the asserter can talk about the stuff's provenance with respect to the set of properties that have been declared fixed?
>> Thanks
>> Paul
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Dr Simon Miles
Lecturer, Department of Informatics
Kings College London, WC2R 2LS, UK
+44 (0)20 7848 1166

Received on Sunday, 26 June 2011 11:25:34 UTC