 Bergman's diamond lemma

Bergman's diamond lemma is a result in the field of universal algebra, named after the mathematician I. N. Bergman. It is a tool used to study certain types of algebraic structures, particularly in the context of modules over a ring and in the theory of algebras. The lemma provides conditions under which certain kinds of "multiplications" can be approximately characterized by simpler forms, often involving a basis of sorts.