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In a series of papers and in his 2009 book on configurations Branko Grunbaum described a sequence of operations to produce new $(n_{4})$ configurations from various input configurations. These operations were later called the Grunbaum Incidence Calculus. We generalize two of these operations to produce operations on arbitrary $(n_{k})$ configurations. Using them, we show that for any $k$ there exists an integer $N_k$ such that for any $n geq N_k$ there exists a geometric $(n_k)$ configuration. We use empirical results for $k = 2, 3, 4$, and some more detailed analysis to improve the upper bound for larger values of $k$.
We define a new class of shift spaces which contains a number of classes of interest, like Sturmian shifts used in discrete geometry. We show that this class is closed under two natural transformations. The first one is called conjugacy and is obtain
A factorisation $x = u_1 u_2 cdots$ of an infinite word $x$ on alphabet $X$ is called `monochromatic, for a given colouring of the finite words $X^*$ on alphabet $X$, if each $u_i$ is the same colour. Wojcik and Zamboni proved that the word $x$ is pe
We investigate the correlation between integrated proton-neutron interactions obtained by using the up-to-date experimental data of binding energies and the $N_{rm p} N_{rm n}$, the product of valence proton number and valence neutron number with res
We discuss several partial results towards proving Dennis Whites conjecture on the extreme rays of the $(N,2)$-Schur cone. We are interested in which vectors are extreme in the cone generated by all products of Schur functions of partitions with $k$
Let $m_2(n, q), n geq 3$, be the maximum size of k for which there exists a complete k-cap in PG(n, q). In this paper the known bounds for $m_2(n, q), n geq 4$, q even and $q geq 2048$, will be considerably improved.