It has been conjectured by Cowan and Emerson [3] that every graph has an unfriendly partition; i.e., there is a partition of the vertex set V= V, v V, such that every vertex of V, is joined to atâ€¦ (More)

We obtain results concerning the behaviour of the function 2 t t (a G On) under the assumption of the existence of certain kind of ideals. These results complement those of Ulam [7], Tarski [6] andâ€¦ (More)

We provide some new Caratheodory-type selection theorems. i.e.. selections for correspondences of two variables which are continuous with respect to one variable and measurable with respect to theâ€¦ (More)

We introduce a notion of weak intersection number of a collection of sets, modifying the notion of intersection number due to J.L. Kelley, and obtain an analogue of Kelleyâ€™s characterization ofâ€¦ (More)