Results 21 to 30 of about 114 (83)
A $\beta$ Invariant for Greedoids and Antimatroids [PDF]
The Electronic Journal of Combinatorics, 1997 We extend Crapo's $\beta $ invariant from matroids to greedoids, concentrating especially on antimatroids. Several familiar expansions for $\beta (G)$ have greedoid analogs. We give combinatorial interpretations for $\beta (G)$ for simplicial shelling antimatroids associated with chordal graphs.
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Cospanning characterizations of antimatroids and convex geometries
CoRR, 2021 Given a finite set $E$ and an operator $σ:2^{E}\longrightarrow2^{E}$, two sets $X,Y\subseteq E$ are \textit{cospanning} if $σ\left( X\right) =σ\left( Y\right) $. Corresponding \textit{cospanning equivalence relations} were investigated for greedoids in much detail (Korte, Lovasz, Schrader; 1991).
Yulia Kempner, Vadim E. Levit
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Matroids and antimatroids—a survey
Discrete Mathematics, 1989 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
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Correspondence between two Antimatroid Algorithmic Characterizations [PDF]
The Electronic Journal of Combinatorics, 2003 The basic distinction between already known algorithmic characterizations of matroids and antimatroids is in the fact that for antimatroids the ordering of elements is of great importance.While antimatroids can also be characterized as set systems, the question whether there is an algorithmic description of antimatroids in terms of sets and set ...
Yulia Kempner, Vadim E. Levit
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The Forbidden Minor Characterization of Line-Search Antimatroids of Rooted Digraphs [PDF]
, 2002 An antimatroid is an accessible union-closed family of subsets of a finite set. A number of classes of antimatroids are closed under taking minors such as point-search antimatroids of rooted (di)graphs, line-search antimatroids of rooted (di)graphs ...
Nakamura, Masataka +3 more
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Geometry of antimatroidal point sets
CoRR, 2008 14 pages, 3 ...
Yulia Kempner, Vadim E. Levit
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An axiomatization of the Banzhaf value for cooperative games on antimatroids [PDF]
Mathematical Methods of Operations Research (ZOR), 2004 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Encarnación Algaba Durán +3 more
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Cooperative games under augmenting systems [PDF]
, 2003 The goal of this paper is to develop a theoretical framework inorder to analyze cooperative games inwhic h only certaincoalition s are allowed to form.
Bilbao Arrese, Jesús Mario +1 more
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Combinatorics of lopsided sets [PDF]
, 2006 We develop a theory of isometric subgraphs of hypercubes for which a certain inheritance of isometry plays a crucial role. It is well known that median graphs and closely related graphs embedded in hypercubes bear geometric features that involve ...
Bandelt, Hans-Jürgen +3 more
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Antimatroids, Betweenness, Convexity [PDF]
, 2008 Two classical examples of antimatroids arise from double shellings of partially ordered sets and from simplicial shellings of triangulated graphs. The corresponding convex geometries have Caratheodory number two and admit a natural description in terms of the ternary relation of betweenness in the underlying structure.
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