The complexity of the isomorphism problem for regular trees, regular linear orders, and regular words is analyzed. A tree is regular if it is isomorphic to the prefix order on a r...
Error correcting codes and matroids have been widely used in the study of ordinary secret sharing schemes. In this paper, we study the connections between codes, matroids, and a s...
Ronald Cramer, Vanesa Daza, Ignacio Gracia, Jorge ...
We consider submodular optimization problems, and provide a general way of translating oracle inapproximability results arising from the symmetry gap technique to computational co...
We show that for most complexity classes of interest, all sets complete under rstorder projections (fops) are isomorphic under rst-order isomorphisms. That is, a very restricted v...
Abstract. The maximum intersection problem for a matroid and a greedoid, given by polynomial-time oracles, is shown NP-hard by expressing the satisfiability of boolean formulas in...