On the dual König property of the order - interval hy - pergraph of a new class of poset
نویسنده
چکیده
Let P be a finite poset. We consider the hypergraph H(P ) whose vertices are the elements of P and whose edges are the maximal intervals of P . It is known that H(P ) has the König and dual König properties for the class of series-parallel posets. Here we introduce a new class which contains series-parallel posets and for which the dual König property is satisfied. For the class of N-free posets, again a generalization of series-parallel posets, we give a counterexample to see that the König property is not satisfied.
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