Heinz-Jürgen Voss

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The prism over a graph G is the Cartesian product G2K 2 of G with the complete graph K 2. If G is hamiltonian, then G2K 2 is also hamiltonian but the converse does not hold in general. Having a hamiltonian prism is shown to be an interesting relaxation of being hamiltonian. In this paper, we examine classical problems on hamiltonicity of graphs in the(More)
A mixed hypergraph is a triple H = (X, C, D), where X is the vertex set and each of C, D is a family of subsets of X, the C-edges and D-edges, respectively. A proper k-coloring of H is a mapping c : X → [k] such that each C-edge has two vertices with a common color and each D-edge has two vertices with distinct colors. A mixed hypergraph H is called(More)