John F. Sowa's Conceptual Graphs allow the graphical statement of logic propositions, or predicates. Like the Unified Modeling Language, they allow construction of statements such as

• "England expects that every man will do his duty". -- Horatio Nelson

Sowa credits the Existential Graphs of Charles Sanders Peirce for his conceptual graphs. Together with concepts like conceptual schema, semantic network, knowledge representation, principal components analysis, Tuevo Kohonen's self-organizing map and Bayesian inference, Sowa's conceptual graphs may eventually make it possible to implement agents for unsupervised learning.

Reference: John F. Sowa, Conceptual Structures 1984 IBM Systems Programming Series ISBN 0-201-14472-7

External Link: John F. Sowa (http://www.jfsowa.com/cg/cgexamp.htm)