Mirsky's theorem

Mirsky's theorem

[′mir·skēz ‚thir·əm]
(mathematics)
The theorem that, in a finite partially ordered set, the maximum cardinality of a chain is equal to the minimum number of disjoint antichains into which the partially ordered set can be partitioned.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.