Contexts, canons and coreferent types
A major area of development in the field of knowledge representation is the idea of contexts. In a large system a reasoner can't re-examine everything known all the time. To deal with the shear size and complexity of large knowledge bases like CYC, a reasoner must be able to limit its search to some context relevant to the immediate problem at hand.
In the theory of conceptual graphs, Sowa has defined contexts as containers of graphs and canons as well-defined knowledge bases. Others, in particular Guha, have defined other versions of contexts. His most notably use of contexts is as the basis for his microtheories and lifting rules.
This paper reviews the conceptual graph theory of contexts and canons. It shows how canons can be viewed as contexts+types+individuals. It gives examples of two canons having the same type, called type coreference, and formalizes their meaning. Lastly, it gives examples of how higher order logic statements can be made using canons. A companion paper  compares and contrasts conceptual graph and microtheory contexts.
KeywordsContext Conceptual Graph Concept Canon Higher Order Logic
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