A pooling space is a ranked poset P such that the subposet w+ induced by the elements above w is atomic for each element w of P. Pooling spaces were introduced in [Discrete Mathem...
We introduce a new graph for all whose cartesian powers the vertex isoperimetric problem has nested solutions. This is the fourth kind of graphs with this property besides the wel...
Catalan numbers C(n) = 1 n+1 2n n enumerate binary trees and Dyck paths. The distribution of paths with respect to their number k of factors is given by ballot numbers B(n, k) = n-...
Rahilly [10] described a construction that relates any Hadamard design H on 4m -1 points with a line spread to an affine design having the same parameters as the classical design ...
Vassili C. Mavron, T. P. McDonough, Vladimir D. To...
A homogeneous factorisation of a digraph consists of a partition P = {P1, . . . , Pk} of the arc set A and two vertex-transitive subgroups M G Aut() such that M fixes each Pi set...
Michael Giudici, Cai Heng Li, Primoz Potocnik, Che...
The core of a game v on N, which is the set of additive games dominating v such that (N) = v(N), is a central notion in cooperative game theory, decision making and in combinator...