On matching extensions with prescribed and proscribed edge sets II
نویسندگان
چکیده
منابع مشابه
Matching extensions with prescribed and forbidden edges
Suppose G connected graph on p vertices that contains perfect Then G is said to have property n) if p 2: 2(m + n + 1) and if for each pair of disjoint independent M, N E( G) of m, n there exists a perfect matching P in G such that M S;;;; P and 0. We discuss the circumstances under which E(m, n) =? E(x, y), and prove that (surprisingly) in general E(m, n) does not imply E(m, n-1).
متن کاملSets with Prescribed Arithmetic Densities
Using concepts of generalized asymptotic and logarithmic densities based on weighted arithmetic means over an arithmetical semigroup G we prove that under some additional technical assumptions on the weighted counting function of its elements, a subset of G exists with all four generalized densities (upper and lower asymptotic and logarithmic) prescribed subject to the natural condition 0 ≤ d(A...
متن کاملIndependent sets in edge-clique graphs II
We show that edge-clique graphs of cocktail party graphs have unbounded rankwidth. This, and other observations lead us to conjecture that the edge-clique cover problem is NP-complete for cographs. We show that the independent set problem on edge-clique graphs of cographs and of distance-hereditary graphs can be solved in polynomial time. We show that the independent set problem on edge-clique ...
متن کاملOn existence of hypergraphs with prescribed edge degree profile
The degree profile of an edge e of a finite hypergraph H is the map assigning to a positive integer i the number of vertices of degree i incident with e. The edge degree profile of H is the map describing for any possible degree profile ~ the number of edges in H with degree profile ~. A necessary and sufficient condition for existence of hypergraphs of prescribed edge degree profile is found. ...
متن کاملOn extensions, linear extensions, upsets and downsets of ordered sets
We consider the problem of characterizing the set (P ) of all extensions of an order P on a set of elements E, where |E| = n, |P | = m and is the number of extensions of the order. Initially, we describe two distinct characterizations of (P ). The first characterization is a one-to-one correspondence between extensions of P and pairs of upsets and downsets of certain suborders of P . The second...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Discrete Mathematics
سال: 1999
ISSN: 0012-365X
DOI: 10.1016/s0012-365x(99)90035-3