Noun
law of identity
(logic) The logical principle that anything equals itself, expressed by the symbolic equation A=A.
The law of identity states that an apple is an apple.
Because the law of identity partitions its logical Universe into exactly two parts, it creates a dichotomy wherein the two parts are "mutually exclusive" and "jointly exhaustive". Source: Internet
Classic laws of thought The principle of excluded middle, along with its complement, the law of contradiction (the second of the three classic laws of thought ), are correlates of the law of identity (the first of these laws). Source: Internet