DAML-Spatial Primitives

From: Austin Tate (a.tate@ed.ac.uk)
Date: 03/07/03

  • Next message: Antony Galton: "Re: A DAML Spatial Ontology"
    How about the "primitives" Jerry...
    Space              Time
    -----               ----
    location            time-point
                          (interval) <- though I treat that as derived
    The idea being that a neutral word like location which does not restrict
    the meaning to be only one of a "point" or "area" or "volume" and leaves
    nature of the "location" open can be useful to allow relationships to be
    stated to give real meaning. It also then allows relationships to be given
    to grid and coordinate systems in some way.
    This is much like having a temporal ontology primitive like time point
    which allows you to relate time points to one another and to metric time
    descriptions on a calendar or timeline.
    Jerry Hobbs wrote in reply:
    >Good idea.  In the time ontology I tried to axiomatize instants in a
    >way that didn't force one to accept their existence.  So Allen's approach
    >in which everything is an interval is subsumed, and for him the axioms about
    >the properties of instants are all vacuously true.  I think I'd want to
    >do a similar thing for locations -- be silent about whether points actually
    >exist, but axiomatize what their properties would be if they did exist.
    >I'd suggest that you send this bit to daml-spatial, to help get a discussion
    Done via this message.   James Allen and I discussed the issue of time 
    points and time intervals by the way while developing other ontologies such 
    as PIF and NIST PSL and he believe (I hope I am not misrepresenting him) 
    that time points can be seen as primitive and intervals as made up of two 
    time points.  But his temporal calculus then uses these derived intervals 
    of course - which is fine.
    Prof. Austin Tate, Artificial Intelligence Applications Institute, Informatics,
    University of Edinburgh, Appleton Tower, Crichton Street, Edinburgh EH8 9LE, UK
    Tel: +44 131 650 2732 Fax: +44 131 650 6513 E-mail: a.tate@ed.ac.uk 

    This archive was generated by hypermail 2.1.4 : 03/07/03 EST