Knowledge Representations are ways of capturing knowledge and encoding it. The foremost example is Natural Language which has been with the human race in oral form for no-body knows how long and in written form for some more than 5000 years. It achieved sophisticated form certainly no later than 500 BC or earlier -- the works of the great Greek philosophers Three Old Greeks dates from about the mid-350's BC --- today's versions include AI KRL's (Knowledge Representation Languages) ontologies and more commonly the various data base systems.
We still seem to have a long way to go though before we have a system that is complete -- See Incomplete Notations --Ray Schneider
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