This paper considers the following game on a hypercube, first suggested by Lagarias and Saks. Suppose 2 pebbles are distributed onto vertices of an n-cube (with 2 vertices). A pebbling step is to remove two pebbles from some vertex and then place one pebble at an adjacent vertex. The question of interest is to determine if it is possible to get one pebble to a specified vertex by repeatedly usi...

The chromatic number χ(G) of a graph G is the minimum number of colors in a proper coloring of the vertices of G. The biclique partition number bp(G) is the minimum number of complete bipartite subgraphs whose edges partition the edge-set of G. The Rank-Coloring Conjecture (formulated by van Nuffelen in 1976) states that χ(G) ≤ rank(A(G)), where rank(A(G)) is the rank of the adjacency matrix of...

A net (xα) in a vector lattice X is said to uo-converge to x if |xα−x|∧u o −→ 0 for every u ≥ 0. In the first part of this paper, we study some functional-analytic aspects of uo-convergence. We prove that uo-convergence is stable under passing to and from regular sublattices. This fact leads to numerous applications presented throughout the paper. In particular, it allows us to improve several ...

Borodin, Linial, and Saks introduce a general model for online systems in [Borodin et al. 1992] called metrical task systems. In this paper, the unfair two state problem, a natural generalization of the two state metrical task system problem, is studied. A randomized algorithm for this problem is presented, and it is shown that this algorithm is optimal. Using the analysis of unfair two state p...