RE: SUO: RE: RE: A proposed SUO content outline
Dear John,
> Dear Matthew and Ian,
>
> Every term on your outline is necessary for a complete system
> of knowledge representation. Indeed, all of these terms have
> been used for many years in mathematics and physics, and they
> have been formalized, axiomatized, and reasoned and computed
> with in great depth in many different ways for a long time.
>
> The big question is not whether they belong in the SUO. The
> answer to that is simple: yes, of course.
>
> Even the issue of writing definitions and axioms for them is
> not a big problem. There are plenty of axiomatizations for all
> of them that can be taken out of the literature of math, logic,
> and physics, dusted off, and translated into KIF, CGs, and
> many other notations.
>
> One issue that has to be recognized: all those axioms
> were designed for different purposes, and they use very
> different primitives. As an example, I use the Eulerian and
> Langrangian systems of coordinates for fluid mechanics. Many
> of the same phenomena can be represented in either one, but
> the representations have very different structures and
> relationships. That is true of all those categories in
> the outline: there are many, many different coordinate
> systems and representations that have been used, all of them
> are valuable for different purposes, but the relationships
> between them are very far from clear. Taking one coordinate
> system instead of another is a purely arbitrary choice, and
> you have to know how they are related before you can make
> a rational decision about how they should be positioned
> in the ontology.
MW: Are you using an analogy here? If you are saying that
there are different ways to do this SUO, each potentially
useful and valid for different purposes, I agree.
I'm just trying to outline what I think one of them is. I do
not think it should be combined with the work Ian is doing,
but mapped to it. But then I don't control the work that Ian is
doing.
>
> The first thing that has to be determined is which of these
> issues belong to the logic, which of them belong to the
> ontology, how the logic relates to the ontology, and how
> the logic and the ontology relate to the real world and/or
> any possible world, situation, state of affairs, etc. And
> the next thing is how can you reason about them with the
> logic and talk about them with language(s) you want to use.
MW: Yes.
>
> We all know that the knowledge representation must accommodate
> individuals, states, events, space, time, space-time, process,
> activity, agents, etc. But you cannot start to put these things
> into a hierarchy until you have a very clear idea of what these
> things are, how you can refer to them in logic, how they are
> classifiable by the ontology (Note: classifiable is a
> prerequisite to being classified), and how they relate to
> what is in the world, what is perceived by humans, animals,
> or robots, how evidence for them is obtained, etc.
>
> Only after these questions are answered, does it become
> possible to say where you can position the categories in
> the hierarchy, outline, or whatever you want to call it.
MW: Well we have spent many years doing this amongst ourselves
for this set of subject areas in EPISTLE, though using entity
relationship approaches rather than straight FOL. Though as you
have pointed out there is a straigthforward mapping.
>
> Compared to that, questions like the following are a tiny,
> insignificant little nit:
>
> >MW: Do you have some things in the merged ontology that are
> not found here?
>
> >(e.g. holes).
>
> We still haven't answered where the concepts of Circle, Sphere,
> and Cube belong. When we know where those belong, then maybe
> we can begin to talk about holes in a cube or sphere.
MW: Circle would be a shape.
>
> All of Ian's questions about the following list are well taken,
> but that is barely scratching the surface of the ones that must
> be addressed before we can put these topics into some ordering:
MW: It would be a mistake to think that because you have not asked
the questions, none have been asked.
>
> >> > 1. Thing
> >> > 1.1. Individual
> >> > 1.1.1. State
> >> > 1.1.1.1. Period of Time
> >> > 1.1.1.2. Activity
> >> > 1.1.1.3. Physical Object
> >> > 1.1.1.3.1. Materialised Physical Object
> >> > 1.1.1.3.2. Functional Physical Object
> >> > 1.1.1.3.3. Stream
> >> > 1.1.2. Temporal Boundary
> >> > 1.1.2.1. Point in Time
> >> > 1.1.2.2. Event
> >> > 1.2. Collection
> >> > 1.2.1. Class
> >> > 1.2.1.1. Class of Individual
> >> > 1.2.1.1.1. Quantifiable Property
> >> > 1.2.1.1.2. Role
> >> > 1.2.1.1.3. Status
> >> > 1.2.1.1.4. Organisational Level
> >> > 1.2.1.1.4.1. Shape
> >> > 1.2.1.1.5. Information Pattern
> >> > 1.2.1.2. Class of Class
> >> > 1.2.1.2.1. Number
> >> > 1.2.1.2.2. Class of Relation
> >> > 1.2.1.2.2.1. Specialisation
> >> > 1.2.1.2.2.2. Unit of Measure Mapping of Property to Number Space
> >> > 1.2.1.2.2.3. Class of Representation
> >> > 1.2.1.2.2.3.1. Identification
> >> > 1.2.1.2.2.3.2. Definition
> >> > 1.2.1.2.2.3.3. Description
> >> > 1.2.1.3. Relation
> >> > 1.2.1.3.1. Classification
> >> > 1.2.1.3.2. Cause and Effect
> >> > 1.2.1.3.3. Whole-Part
> >> > 1.2.1.3.3.1. Fusion Whole-Part
> >> > 1.2.1.3.3.2. Arrangement Whole-Part
> >> > 1.2.1.3.3.3. Assembly Whole-Part
> >> > 1.2.1.3.3.4. Feature Whole-Part
> >> > 1.2.1.3.3.5. Temporal Whole-Part
> >> > 1.2.1.3.3.6. Participation in Activity
> >> > 1.2.1.3.3.7. Temporal Bounding of State
> >> > 1.2.1.3.3.8. Containment of Individual
> >> > 1.2.1.3.4. Connection
> >> > 1.2.1.3.5. Temporal Sequence
> >> > 1.2.1.3.6. Involvement in Activity
> >> > 1.2.2. Set
>
> Every level of this outline raises very serious questions about
> why things are placed on that level, how they are related to
> their siblings or their parents and children. Why, for example,
> is "period of time" under "state"? What is time? Why is
> "cause and effect" a sibling node of "whole-part"? What is
> causality? How does causality relate to time? Which is more
> fundamental, time or causality? Which one presupposes the
> other in its definition? Why?
MW: Most of these have been asked and answered, but not here.
>
> Having a laundry list of items to be considered is useful.
> But without a very serious answer to all these questions,
> it should not considered as anything that has any more
> structure than a laundry list.
MW: Perhaps we should start on the questions.
> Why, for example, is "period of time" under "state"?
MW: State is any spatio-temporal extent with a non-zero time
component. A period of time here is taken to be a temporal part
of the whole universe during some temporal extent (from some
viewpoint). These may not be the usages of these terms that you
are used to.
MW: There is of course a time dimension, just as there are spatial
dimensions, but these require a frame of reference etc.
> What is time?
MW: Just another dimension, like the spatial ones (however many
there are) but with (apparently) some constraints on the
direction of travel.
> Why is "cause and effect" a sibling node of "whole-part"?
MW: Well it would be more relevant to ask why it is under
Relation. Being a sibling of Whole-Part simply means it isn't
under it. We treat cause and effect has how activities cause
states to start or terminate (events).
> What is causality?
MW: In our use of the term, simply the link between activity
and the change(s) it brings about. There are of course classes
of cause that talk about what types of activity cause what types
of change.
> How does causality relate to time?
MW: Activities are spatio-temporal extents, and events are part of
a point in time (this is a 4D ontology so time is built in). The
link between cause and effect is simply a timeless relation that
notes that this activity is considered to cause this state change.
> Which is more fundamental, time or causality?
MW: I consider that they are inextricably intertwined. As far as I
can see if there are no events, then time does not pass. It is by
certain regular events, such as the Earth turning on its axis, or
encircling the Sun that we measure time.
> Which one presupposes the other in its definition?
MW: I guess we start with time.
>Why?
MW: This is a 4D ontology.
>
> John Sowa
>
Regards
Matthew
============================================
Matthew West
Operations & Asset Management
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