Virtual Worldwide Seminar Project
AI Notions of Context
December 9, 1998
There will be overlap with my 1993 IJCAI article,
http://www-formal.stanford.edu/jmc/context.html, but I'll emphasize
We treat contexts as objects in (mostly) first order theories. The
most basic relation is _Ist(c,p)_ asserting that the proposition _p_
is true in the context _c_. Every assertion, including those about
contexts is made in a context, and therefore when we assert
_Ist(c,p)_, we do it in some context _c0_ and therefore write
Besides propositions, there are individual concepts, and
_Value(c,exp)_ denotes the value that the individual concept _exp_ has
in the context _c_.
We consider relations among contexts such as that one context
specializes another or has a certain relation to that of another.
Here are some ideas and topics that will be discussed.
The problem for AI is to get theories expressed in languages of
mathematical logic within which computer programs can reason about the
relations between objects associated with different contexts.
- "What is context?" is a misleading question to be replaced by "What
kinds of context objects are useful in AI, philosophy and
linguistics?" There are many.
- All assertions about particular contexts are made in contexts.
There is no outermost context, and the outermost considered so far may
- Two contexts with the same true sentences may differ in their
relation to other contexts.
- contexts associated with the beliefs of a person
- contexts associated with the contents of a database
- contexts associated with particular times and places, e.g. this
abstract or the context associated with the actual lecture
- relations between the values of expressions in two different
contexts asserted in a third, outer, context, e.g.
c[this abstract]: Value(c[Stanford-Stockholm seminar of 1998 January
Value(c[Stanford Computer Science Department],John McCarthy).
- contexts associated with assumptions including counterfactuals,
c[if another car had come over the hill when you passed that Lexus]
- contexts associated with mathematical theories, e.g. group theory
or common sense theories about the different kinds of automobiles
- fictional contexts, e.g. that of the Sherlock Holmes stories
Are UP! title.html
(Wed Dec 9 03:59:03 1998)
Gzipped, tarred version (so can look at locally)
- Formal Reasoning Group (Stanford University, USA)
- Mechanized Reasoning Group (DISA, Trento, Italy)
- Paolo Bouquet,
Roger Young, and their colleagues at University of Dundee (Scotland, U.K.)
Sandewall (Linköping university, Sweden)
Spalazzi (University of
- John Barnden (School of Computer Science, University of Birmingham, U.K.)
1 John McCarthy
Room 208, Gates Building 2A [click on the building for directions]
Computer Science Department
Stanford, California 94305-9020