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About the ratio of the size of a maximum antichain to the size of a maximum level in finite partially ordered sets
Authors:Konrad Engel  Nikolaj Nikolajevič Kuzjurin
Institution:1. Sektion Mathematik. Wilhelm-Pieck-Universit?t, 2500, Rostock, German Democratic Republic
Abstract:LetP be a finite partially ordered set. The lengthl(x) of an elementx ofP is defined by the maximal number of elements, which lie in a chain withx at the top, reduced by one. Letw(P) (d(P)) be the maximal number of elements ofP which have the same length (which form an antichain). Further let 
$$p^n : = \underbrace {PX...XP}_{n - times}$$
. The numbers 
$$r_k : = \mathop {\max }\limits_{P:|P| = k} \frac{{d(P)}}{{w(P)}}$$
and 
$$s_k : = \mathop {\max }\limits_{P:|P| = k} \mathop {\lim }\limits_{n \to \infty } \frac{{d(P^n )}}{{w(P^n )}}$$
as well as all partially ordered sets for which these maxima are attained are determined.
Keywords:06 A 10  05 A 99
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