Isomorphic ANTI-cores of caccc posets — an improvement Original Research Article

It was proved in Li and Milner (1996) that for a connected caccc poset which does not contain a one-way infinite fence, any two ANTI-perfect sequences have the same length and any two ANTI-cores are isomorphic. In the present paper we give a new proof of this result under the weaker assumption that the poset is caccc; the conditions that the poset be connected and contain no one-way infinite fence are not required.