Yoneda lemma

Etymology
Lemma named after the Japanese mathematician Nobuo Yoneda (1930–1996).

Noun

 * 1)  Given a category $$\mathcal{C}$$ with an object A, let H be a hom functor represented by A, and let F be any functor (not necessarily representable) from $$\mathcal{C}$$ to Sets, then there is a natural isomorphism between Nat(H,F), the set of natural transformations from H to F, and the set F(A). (Any natural transformation $$\alpha$$ from H to F is determined by what $$\alpha_A(\mbox{id}_A)$$ is.)

Translations

 * Chinese:
 * Mandarin: 米田引理
 * French: lemme de Yoneda
 * German: Lemma von Yoneda
 * Italian: lemma di Yoneda
 * Japanese: 米田の補題
 * Korean: ^요네다 보조정리
 * Portuguese: lema de Yoneda
 * Spanish: lema de Yoneda