Re: SUO: RE: OpenCyc problems
On Mon, Jun 23, 2003 at 04:55:42PM -0400, Patrick Cassidy wrote:
>
> Eric --
> >
> > [ELP] Pat, in OpenCyc 0.7.0 12-15-02 (which is the latest version)
> > SOSS is not any sort of generalization of PC.
> >
> Right. I didn't check the latest version before
> sending the note. Moving target.
>
> >
> > I think I remember you bring up the function issue at VerticalNet.
> >
> > How did Cycorp respond to your concerns? I'd like to see their
> > responses.
> >
> I haven't seen a response.
>
> >
> > [ELP] The OpenCyc IDE doesn't supply constant grepping out of the box
> > like full-Cyc. And I couldn't find "Process" in an initial substring of
> > any constant. I need a text version like yours to search, but of the
> > current version.
> >
> > To what specific process-related constant are you referring?
> >
> There are several examples, but the "processes" in CYC are named
> with "process" at the end, not beginning. They are all subclasses
> of "Event". One gets, for example, the branch
> . . .
> TransformationEvent
> TransformationProcess
> DecompositionEvent
>
> . . . which shows that "Event" and "Process" are considered
> subclasses of each other -- no real distinction. The
> distinctions seem to come only in the metaclass "Type"
> classes:
That's right. There is no significant distinction between an event and a
process. There are only various types of events. Some events are
"logically instantaneous," in the sense that semantically they can be
regarded as occurring at an indivisible time interval. Some events
aren't. Some of these distinctions may not be in the latest versions,
sorry but I actually don't follow opencyc that closely in my daily work.
>
> (#$isa #$DecompositionEvent #$TemporalObjectType)
> (#$isa #$DecompositionProcess #$TemporalStuffType)
>
> Where "stuff" has some continuous character.
"stuff" doesn't imply temporal continuity (as opposed to discreteness).
"Stuff" means something like qualitative continuity: if G is a stuff-like
property, proper temporal parts of any G instance inherit its G-ness. I
believe that either the Leipzig group or Aldo Gangemi have a nice
classification of meta-properties such as this; Pierre Grenone can set us
straight.
>
> I don't know how these metaclass distinctions are
> applied in CYC. I presume their applications find some
> way around what appears to me at least clumsy and possibly
> a logical inconsistency. The use of metaclasses to make
> such distinctions is to me one of the serious weaknesses of
> CYC as a standard. It is unnecessary and makes the structure
I actually find metaclasses a very intuitive way to classify .... well,
classes -- just as second-order properties seem to be useful in
classifying properties. Why do you think that's obscure?
> more obscure, which is a serious detriment in a standard that
> needs to be widely used in order to serve its function. Perhaps
> if a Cyclist would explain where and how F=ma is represented
> (I mean the physical phenomenon, not the mathematical equation,
> or the classification of "acceleration" as a physical quantity),
> it would make the reasons for their choices clearer.
INteresting question, but:
(i) what do you mean by the physical phenomenon "as opposed to" the
equation? I suspect most people think the equation is a representation of
the "phenomenon" (of course, where "phenomenon" is used in something like
a stricter sense, this can't really be a phenomenon. No law can.)
(ii) how is this problem related to the meta-classes issue?
> The Cyc representation of "process" as a series of discrete
> steps is not unusual -- it is the same in SUMO and PSL. There
I don't believe process is represented that way. Nor do I think it
should. Sorry but I gotta go. Will follow your response, if any.
Good questions all of them. Best,
> is a long history of the use of the word "process" to refer to
> such sequences. I'm not hung up on terminology. But there
> is a distinction between "something happening at some point in time"
> and "something that happened in some time interval", which does
> not seem to be adequately represented in OpenCyc. The WordNet
> has "process" and "event" in two separate branches, neither a
> subtype of the other. I believe that this corresponds more
> closely to the linguistic distinctions that are found for
> many uses of the gerund "-ing" to refer to things happening at
> some point, in contrast to time-delimited actions. Both of
> these are important concepts to have at our disposal for
> representing physical phenomena and the way people talk
> about them.
>
> >
> >>and substances which are more abstract
> >>than pieces of a particular substance.
> >
> >
> > [ELP] I'm not sure that I understand this second one. Can you point me
> > to the offending axioms?
> >
> >
> The problem is in the usage in Cyc that any "Substance" is
> represented as a piece of substance, a physical object. A
> substance like water is only a subtype of tangible things.
> In some cases things that are considered "substances" in
> everyday parlance (water, oil, whiskey) are distinguished by
> the use of metaclasses like "#$TangibleStuffCompositionType"
>
> Take the definitions of #$NaturalTangibleStuff,
> "OrganicStuff" and "Water":
>
> OPENCYC 1: MAY 23, 2002
> An instance of #$ExistingStuffType and a sub-collection of
> #$PartiallyTangible. Each instance of #$NaturalTangibleStuff is a
> naturally occurring partially tangible thing. Specializations of
> #$NaturalTangibleStuff include #$EarthStuff, #$Wood, and #$Air.
> Man-made materials are _not_ instances of #$NaturalTangibleStuff.
>
> (#$comment #$OrganicStuff "A collection of tangible things. Each
> instance of #$OrganicStuff is a tangible thing composed of one or more
> types of organic #$Molecule. Instances of #$OrganicStuff usually have
> their origin in the bodies (or other products) of living things.
> Since some organic substances can be synthesized, #$OrganicStuff is
> not a subcollection of #$NaturalTangibleStuff. Chemically, instances
> of #$OrganicStuff have fairly (or very) complex carbon-based
> structures. Examples include all instances of the collections #$Oil,
> #$DNAStuff, #$Alcohol-Compound, #$Ivory, and #$AnimalBodyPart.")
>
> OPENCYC 1: MAY 23, 2002
> A collection of tangible things and a subcollection of #$Oxide. Each
> instance of #$Water is one piece of some portion of the chemical
> compound H2O. Instances of #$Water may be in a gaseous, liquid, or
> solid state (see #$stateOfMatter); they may be salty, not salty,
> drinkable, or not drinkable. Examples include portions of the ocean,
> such as the #$BayOfBiscay and the #$BayOfBengal (see also #$SeaWater);
> bodies of fresh water, such as #$NiagaraFalls or the #$GangesRiver;
> quantities of chlorinated water (see #$PoolWater); and the contents of
> bottles of tonic water (see #$SeltzerWater). Any portion of liquid
> that consist mostly of water but differs from it in one or more
> important properties (e.g. urine, coffee, and lemonade) is not itself
> an instance of #$Water, but has an instance of #$Water as its main
> constituent (see #$mainConstituent).
>
>
> Consider these metaclasses:
>
> (#$isa #$NaturalTangibleStuff #$ExistingStuffType)
> (#$isa #$InorganicStuff #$ExistingStuffType)
> (#$isa #$OrganicStuff #$TangibleStuffCompositionType)
>
> Why do organic stuff and inorganic stuff have different
> metaclasses?
>
> How about Water?
> (#$genls #$Water #$InanimateThing)
> (#$genls #$Water #$Individual)
> (#$isa #$Water #$ChemicalSubstanceType)
> (#$isa #$Water #$TemporalStuffType)
>
> It has none of the metaclasses of either organic stuff or
> inorganic stuff or NaturalTangibleStuff.
>
> The only thing in common is that these things are
> "#$PartiallyTangible" (i.e. physical objects). Why partially?
> What part of water is intangible?
>
> My head reels trying to figure out why there are differences like
> this and how they are used. Of course, there is or once was
> some rationale, and Cyc does somehow manage to use them --
> lots of clever people at Cycorp -- but I feel sorry for the
> contortions they must have to go through.
> Certainly the notion that a "substance" is a piece of some matter
> does not conform to the way I heard the term used for thirty years
> in the laboratory. Things are *composed of* substances, they aren't
> subtypes of substances. A "piece of iron" isn't a part of a larger
> piece of iron, it's an object made of iron. It appears that at an
> early phase someone at Cyc tried to shoehorn the notion of "composed
> of" into some kind of "part of" predicate. It got distorted in the
> process.
>
> I think that the fundamental problem is a failure in Cyc to have
> a more abstract class of Substance -- it could be done in several
> ways, but the outline of the one that I find most flexible is:
>
> A class called PhysicalSubstanceType -- abstract and primitive,
> corresponding to "composition" as expressed in terms like water,
> oil, meat, wood, metal, etc. -- mass nouns. This allows every
> different mixture to be a different substance, e.g. a mixture of
> NaCl and water in a mass ratio of 2/100 would be one SubstanceType --
> a saline solution of specified concentration. Each SubstanceType has
> a minimum granularity.
> A Class called "Substance" which would also be abstract, but
> would correspond to a SubstanceType at a particular density,
> such as NaCl at 20 g/l. A Substance need not occupy all
> of space -- it can be part of a mixture. NaCl at 20 g/l can
> be located in the same volume as water at 990 g/l, and if
> those are the only two Substances in that volume it would
> be a 2% saline solution.
> A particular volume of a Substance (a SubstanceType at a particular
> density) would be a QuantityOfSubstance -- a physical object with
> a mass (volume x density = mass) of a particular SubstanceType.
> This Object does not have to fill space, it can co-occupy a
> region of space with other Quantities of substances. So we
> can consider the 20 grams of NaCl in the solution in my
> beaker as a QuantityOfSubstance.
> If one wants to specify that a substance takes up all the
> space -- that it is all there is there -- it can be done either
> with a property ("neat") or by making it a subclass of
> "SpaceFillingObject".
>
> These distinctions provide one with the flexibility to describe
> mixtures and their properties.
>
> I suppose Cyc has some mechanism to handle mixtures, but I did ask
> about that once and never got a reply.
>
> I could discuss this further, but it would seem to be better
> to put it off until we start a thread on "Substances" and
> homogeneous objects.
>
> Bottom line -- Doug Lenat was fond of saying that everything that
> was put into Cyc was put there because it was needed. That's a good
> philosophy. We should put things into the SUO because they are
> needed, not because at some time someone for some reason thought
> that they might be useful (or merely adequate) for one of Cyc's
> applications.
>
> I think an abstract substance is needed to handle mixtures
> properly.
>
> Pat
>
> =============================================
> Patrick Cassidy
>
> MICRA, Inc. || (908) 561-3416
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>
> internet: cassidy@micra.com
> =============================================
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