Some Remarks on Pseudotrees

Carlos Alós-Ferrer, University of Konstanz
Klaus Ritzberger, Institute for Advanced Studies, Vienna

Abstract

This paper provides new results on pseudotrees. First, it is shown that pseudotrees are precisely those posets for which consistent sets, directed sets, and nonempty chains coincide. Second, we show that chain-complete pseudotrees yield complete meet-semilattices. Third, we prove that pseudotrees are precisely those posets that admit a set representation by sets of appropriate chains. This latter result generalizes results needed for applications in game theory and economics.