A word is abelian square-free if it does not contain two adjacent subwords which are permutations of each other. Over an alphabet k on k letters, an abelian squarefree word is max...
A construction is described for combining affine designs with complete sets of mutually orthogonal frequency squares to produce other complete sets. Key words: Matrices, orthogona...
We constructively prove that the partially ordered set of finite permutations ordered by deletion of entries contains an infinite antichain. In other words, there exists an infini...
: We prove two extensions of the Hales-Jewett coloring theorem. The first is a polynomial version of a finitary case of Furstenberg and Katznelson's multiparameter elaboration...
The idea of graph compositions, which was introduced by A. Knopfmacher and M. E. Mays, generalizes both ordinary compositions of positive integers and partitions of finite sets. ...