The setup polyhedron of series-parallel posets
نویسندگان
چکیده
منابع مشابه
The Permutahedron of Series-parallel Posets
The permutahedron Perm(P) of a poset P is defined as the convex hull of those permutations that are linear extensions of P. Von Arnim et al. (1990) gave a linear description of the permutahedron of a series-parallel poset. Unfortunately, their main theorem characterizing the facet defining inequalities is only correct for not series-decomposable posets. We do not only give a proof of the revise...
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The poset retraction problem for a poset P is whether a given poset Q containing P as a subposet admits a retraction onto P, that is, whether there is a homomorphism from Q onto P which fixes every element of P. We study this problem for finite series-parallel posets P. We present equivalent combinatorial, algebraic, and topological charaterisations of posets for which the problem is tractable,...
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We investigate the Tutte polynomial f(P; t, z) of a series-parallel partially ordered set P. We show that f(P) can be computed in polynomial-time when P is series-parallel and that series-parallel posets having isomorphic deletions and contractions are themselves isomorphic. A formula forf’(P*) in terms off(P) is obtained and shows these two polynomials factor over Z[t, z] the same way. We exam...
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N-free posets have recently taken some importance and motivated many studies. This class of posets introduced by Grillet [8] and Heuchenne [11] are very related to another important class of posets, namely the series-parallel posets, introduced by Lawler [12] and studied by Valdes et al. [21]. This paper shows how N-free posets can be considered as generalizations of series-parallel posets, by ...
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We show that a set of uniformly width-bounded infinite seriesparallel pomsets is ω-series-rational iff it is axiomatizable in monadic second order logic iff it is ω-recognizable. This extends recent work by Lodaya and Weil on sets of finite series-parallel pomsets in two aspects: It relates their notion of series-rationality to logical concepts, and it generalizes the equivalence of recognizabi...
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ژورنال
عنوان ژورنال: Discrete Applied Mathematics
سال: 1997
ISSN: 0166-218X
DOI: 10.1016/s0166-218x(97)00044-9