Nedyalko Dimov Nenov

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Let a1, . . . , ar be positive integers, m = ∑r i=1(ai−1)+1 and p = max{a1, . . . , ar}. For a graph G the symbol G → {a1, . . . , ar} denotes that in every r-coloring of the vertices of G there exists a monochromatic ai-clique of color i for some i = 1, . . . , r. The vertex Folkman numbers F (a1, . . . , ar; m − 1) = min{|V (G)| : G → (a1 . . . ar) and(More)
Tort in [4] drew attention to the problem of the minimum number of vertices of the 5-chromatic graphs, not containing 4-cliques. Hanson et al. in [1] solve this problem by proving that the minimum number of vertices equals 11. But perhaps they were not aware that in paper of Nenov [3] given in the references under N 3 by them, the problem has already been(More)
Let G be a graph and V (G) be the vertex set of G. Let a1 ,. . . , ar be positive integers, m = ∑ r i=1 (ai−1)+1 and p = max{a1, . . . , ar}. The symbol G → {a1, . . . , ar} denotes that in every r-coloring of V (G) there exists a monochromatic ai-clique of color i for some i = 1, . . . , r. The vertex Folkman numbers F (a1, . . . , ar ; m − 1) = min{|V(More)
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