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    The chain covering number of a poset with no infinite antichains

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    The chain covering number \Cov(P) of a poset PP is the least number of chains needed to cover PP. For a cardinal ν\nu, we give a list of posets of cardinality and covering number ν\nu such that for every poset PP with no infinite antichain, \Cov(P)\geq \nu if and only if PP embeds a member of the list. This list has two elements if ν\nu is a successor cardinal, namely [ν]2[\nu]^2 and its dual, and four elements if ν\nu is a limit cardinal with \cf(\nu) weakly compact. For ν=ℵ1\nu= \aleph_1, a list was given by the first author; his construction was extended by F. Dorais to every infinite successor cardinal ν\nu.Comment: P page
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