Minimal trees and monophonic convexity
Discussiones Mathematicae. Graph Theory, Tome 32 (2012) no. 4, pp. 685-704
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Let V be a finite set and a collection of subsets of V. Then is an alignment of V if and only if is closed under taking intersections and contains both V and the empty set. If is an alignment of V, then the elements of are called convex sets and the pair (V, ) is called an alignment or a convexity. If S ⊆ V, then the convex hull of S is the smallest convex set that contains S. Suppose X ∈ ℳ. Then x ∈ X is an extreme point for X if X∖x ∈ ℳ. A convex geometry on a finite set is an aligned space with the additional property that every convex set is the convex hull of its extreme points. Let G = (V,E) be a connected graph and U a set of vertices of G. A subgraph T of G containing U is a minimal U-tree if T is a tree and if every vertex of V(T)∖U is a cut-vertex of the subgraph induced by V(T). The monophonic interval of U is the collection of all vertices of G that belong to some minimal U-tree. Several graph convexities are defined using minimal U-trees and structural characterizations of graph classes for which the corresponding collection of convex sets is a convex geometry are characterized.
Keywords:
minimal trees, monophonic intervals of sets, k-monophonic convexity, convex geometries
@article{DMGT_2012_32_4_a6,
author = {C\'aceres, Jose and Oellermann, Ortrud and Puertas, M.},
title = {Minimal trees and monophonic convexity},
journal = {Discussiones Mathematicae. Graph Theory},
pages = {685--704},
publisher = {mathdoc},
volume = {32},
number = {4},
year = {2012},
language = {en},
url = {http://geodesic.mathdoc.fr/item/DMGT_2012_32_4_a6/}
}
TY - JOUR AU - Cáceres, Jose AU - Oellermann, Ortrud AU - Puertas, M. TI - Minimal trees and monophonic convexity JO - Discussiones Mathematicae. Graph Theory PY - 2012 SP - 685 EP - 704 VL - 32 IS - 4 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/DMGT_2012_32_4_a6/ LA - en ID - DMGT_2012_32_4_a6 ER -
Cáceres, Jose; Oellermann, Ortrud; Puertas, M. Minimal trees and monophonic convexity. Discussiones Mathematicae. Graph Theory, Tome 32 (2012) no. 4, pp. 685-704. http://geodesic.mathdoc.fr/item/DMGT_2012_32_4_a6/