Definitions in mathematics are always stipulative definitions. They are stipulative in the sense that they specify usage rather than report usage. Stipulative definitions do not have a truth value. They are neither true nor false - they just are! A definition in mathematics does not announce what has been meant by the word in the past or what it commonly means now. Rather it announces (stipulates) what will be meant by the word (or term) in the present work. Unlike extracted definitions, stipulative definitions cannot be reliably learned by repeated exposure to instances of the definition. They must be memorized.