Zorn's lemma

noun

ˈzȯrnz-  ˈtsȯrnz- 

: a lemma in set theory: if a set S is partially ordered and if each subset for which every pair of elements is related by exactly one of the relationships "less than," "equal to," or "greater than" has an upper bound in S, then S contains at least one element for which there is no greater element in S compare axiom of choice

Word History

Etymology

Max August Zorn †1993 German mathematician

First Known Use

circa 1950, in the meaning defined above