RE: SUO: RE: A proposed SUO content outline
Dear Pat and Ian,
> > >
> > > State
> > >
> > > Contains axioms and relations that apply to all individuals
> > > that have a non-zero temporal extent.
> >
> >I don't see how "State" differs from "Individual". Since
> all individuals
> >exist in space/time, wouldn't they necessarily have a
> non-zero temporal
> >extent?
>
> No. Something can be temporally located but have a zero extent.
> Timepoints are the obvious example, but more 'physical' examples
> might be instantaneous events like lightning flashes, or beginning
> and endings of longer events.
MW: Actually lightning flashes would not count for us. The duration is
certainly very short, but it is both finite and positive. Only the beginning
and ending of states, and points in time qualify.
>
> > >
> > > Period of Time
> > >
> > > Contains axioms and relations that apply to all individuals
> > > that cover all of space between two points in time.
> >
> >The corresponding axioms and relations in the merged
> ontology can be found
> >in the section "Temporal Definitions/Axioms".
> >
> > >
> > > Activity
> > >
> > > Contains axioms and relations that apply to all individuals
> > > that are something happening to bring about change.
> >
> >As I've mentioned in other emails, the subject of change has not been
> >systematically addressed in the merged ontology. I'm researching the
> >possibility of incorporating something like the Situation
> Calculus, and I
> >would welcome any suggestions along these lines.
>
> The situation calculus is hopelessly limited for a general physical
> ontology. A process ontology would be a more generally useful overall
> framework.
MW: This is what I think we call Activity.
> There are a number of quite elaborate process ontologies
> in the public domain, any of which would be better than the sitcalc.
> At a minimum, we need notions of process and subprocesss;
MW: We have this.
> combinations of processes into larger processes including temporal
> sequencing,
MW: We have this.
> conditions,
MW: Depends what you mean, but we certainly have some capability here.
> parallel operations
MW: Depends what you mean, but at least nothing to prevent this.
> and ideas like a process
> which 'spawns' other processes.
MW: How about one activity causing the start of another?
> We need to be able to reason both
> forwards and backwards in time in a uniform framework,
MW: Out of the box with 4D.
> and we need to
> be able to talk about constraints on processes (and classes of
> processes) in terms of temporal and spatial constraints at the
> boundaries, things and materials involved in the processes (either
> being changed by them or required for them), and things conserved by
> the process.
MW: We can do all that.
>
<snip>
> >
> > >
> > > Status
> > >
> > > Contains axioms and relations that apply to all classes that
> > > are characteristics or qualities that is described by discrete,
> > > unordered values.
> >
> >I agree that this is an important category, and it is also a
> gap in the
> >current version of the merged ontology.
>
> I have no clear idea what you guys are agreeing on. Can anyone give a
> couple of examples of what this means?
MW: examples would be painted, open, approved.
>
> >
> > >
> > > Organisational Level
> > >
> > > Contains axioms and relations that apply to all classes that
> > > define the level of structure, e.g. atom, molecule, cell,
> > > organism.
> >
> >I'm not sure exactly what you mean here. Do you envision
> having a predicate
> >that would relate a class with a quantitative or qualitative
> attribute
> >specifying the level of granularity of the class? This
> might be a good
> >idea, and there is nothing like this in the current version
> of the ontology.
> >Note that the folks at the Ontology Group at ITBM-CNR have
> developed an
> >ontology called "Granularity" to cover just this sort of
> representational
> >need.
>
> Everyone agrees that there is a need for this, but not many people
> know how to do it!
MW: I think we have identified some general principles and some useful
organisational levels(following some of Nicola's work) but I agree there is
a lot of work to do here.
>
<snip>
>
> >
> > >
> > > Set
> > >
> > > Contains axioms and relations that apply to all mathematically
> > > defined sets.
>
> The idea of a 'mathematically defined' set is a bad idea. There is no
> clear category of a mathematical definition (as opposed to a
> nonmathematical one), and in any case what is in a set isn't
> determined by the form of the definition.
MW: No but what things are sets is. I only mean here that to be a set you
must be iteratively constructed, and you can't for example have yourself as
a member. As far as I can make out this is common ground for what a set is
consdered to be. But I'm prepared to hear that the contrary is true.
>
> >This is covered in the new and provisional "Set Theory"
> section of the
> >merged ontology.
Regards
Matthew
============================================
Matthew West
Operations & Asset Management
Shell Services International
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E-mail: Matthew.R.West@is.shell.com
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