antichain

from The Free On-line Dictionary of Computing (8 July 2008)

antichain

   <mathematics> A subset S of a {partially ordered set} P is an
   antichain if,

    for all x, y in S,  x <= y  =>  x = y

   I.e. no two different elements are related.

   ("<=" is written in {LaTeX} as {\subseteq}).

   (1995-02-03)