A definition should be neither too broad nor too narrow. A definition should not be expressed in ambiguous, obscure, pedantic or figurative language. 5.A definition should be affirmative where possible. Extensional definitions provide meaning for a term by identifying members of the class of things named by that term. These kinds of definitions assume you know the examples used.
Logic includes categorical logic, propositional logic and fuzzy logic.
Mary, John, Ellen and Sergei are all bakers. These definitions work fine, if the examples are already known. Eleanor Rosch on Definitions and Categorization Recent work by Eleanor Rosch on categorization stresses the fuzzy nature of classes. And carrots were a better example of vegetable than were pickles. A basic category is the largest class of which we can form a fairly concrete image, like chair or ball.