自じ同どう律りつじどうりつMeanings1nounlaw of identity; principle of identitylogicTechnical term in logic; refers to the axiom that each thing is identical with itself (A = A).自じ同どう律りつは論ろん理り学がくの基き本ほん原げん理りの一ひとつである。The law of identity is one of the fundamental principles of logic.