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EJC
2006
14 years 11 months ago
2006
Abstract. We show that the tree-width of a graph can be defined without reference to graph vertices, and hence the notion of tree-width can be naturally extended to matroids. (This...
EJC
2006
14 years 11 months ago
2006
For a fixed polyomial f Z[X], let k(N) denote the maximum size of a set A {1, 2, . . . , N} such that no product of k distinct elements of A is in the value set of f. In this pap...
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EJC
2002
14 years 11 months ago
2002
In this short note the neighbourhood graph of a Cayley graph is considered. It has as nodes a symmetric generating set of a finitely-generated group . Two nodes are connected by a...
122
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EJC
2008
14 years 12 months ago
2008
Partially ordered sets labeled with k labels (k-posets) and their homomorphisms are examined. The homomorphicity order of k-posets is shown to be a distributive lattice. Homomorph...
EJC
2008
14 years 12 months ago
2008
The aim of this note is to give some factorisation formulas for different versions of the Macdonald polynomials when the parameter t is specialized at roots of unity, generalizing...