The Description List of Concepts A concept is defined as a class of objects whose members can be distinguished by processing its properties. Property is defined to mean a partition of the set of all objects into disjoint classes. The formal definition of a concept is recursive in nature. A concept is described by a list structure. A one-to-one correspondence is established between the recursive definition of a concept and its description list structure. Like the definition, the description list structure of a concept is also built up from elementary list structures by a recursive process. The list structures obtained this way are compared with the description list structure discussed by the author in a previous publication. CACM August, 1962 Banerji, R. B. CA620801 JB March 17, 1978 7:39 PM 527 5 527 527 5 527 527 5 527