Lemma (mathematics)

In mathematics, a lemma is a proven proposition which is used as a stepping stone to a larger result rather than an independent statement, in and of itself. A good stepping stone leads to many others, so some of the most powerful results in mathematics are known as lemmas: Zorn's lemma, Bézout's lemma, Gauss lemma, Fatou's lemma, Nakayama lemma, etc. There is no inherent distinction between a lemma and a theorem.

References

• N. Higham, Handbook of writing for the mathematical sciences, Society for Industrial and Applied Mathematics, 1998 (p. 16)