Dick,

It seems to me that:

> Every proposition has a context that defines the terms and assumptions of the proposition.

Could be written:

Every proposition is part of an ontology/theory that defines the terms in the proposition and the axioms that surround it.

Similarly:

> The context may be expressed as a list of propositions.

> context name :: { defining proposition list };

> at context name { proposition list };

may be written :

(IF (AND <defining proposition list> )

(AND <proposition list> ))

which is only to say that the proposition list in context is just another proposition.

What you are proposing is then strictly a notational difference, presumably based on the possible languages in which {proposition-list} may be written.

Which leads to the real issue:

The more serious problems with ‘context’ (as most of us understand it) are:

a) the knowledge engineer does not know
__exactly__ what the ‘context’ is, and

b) if s/he does, s/he may not have a notation in which it can be formally captured.

-Ed

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Edward J. Barkmeyer Email: edbark@xxxxxxxx

National Institute of Standards & Technology

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**From:** ontolog-forum-bounces@xxxxxxxxxxxxxxxx [mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx]
**On Behalf Of **Richard H. McCullough

**Sent:** Friday, February 21, 2014 11:49 AM

**To:** [ontolog-forum]

**Cc:** Adam Pease; Brian Riley; Richard S. Latimer

**Subject:** [ontolog-forum] context, space-time, group hierarchy

I hope that this brief note will clarify a few key ideas that I have discussed previously.

1. context

Every proposition has a context that defines the terms and assumptions of the proposition.

The context may be expressed as a list of propositions.

context name :: { defining proposition list };

at context name { proposition list };

2. space-time

Propositions may describe actions which cause changes over space-time.

Therefore context must include space, time component.

3. group hierarchy

Some propositions describe a group hierarchy, and it is useful to separate the

hierarchy propositions from the other propositions.

There are two interesting types of groups in use today

Class

Rand concept

I mistakenly believed that Rand concepts were appropriate for RDF, OWL, CycL.

I need to revise all my knowledge bases to use Class instead.

Briefly stated, we may say that

Class is group of individuals with 0 or more members

Rand concept is group of individuals with 2 or more members,

similar characteristics

Ayn Rand required 2 or more members to distinguish between abstract groups

and concrete individuals. Class does not make this distinction.

**Dick McCullough
**

Context Knowledge Systems

mKE and the mKR language

mKR/mKE tutorial