SomeresultsonKronecker,DirichletandHelsonsets T -W K

We give a simple proof of the “tree-width duality theorem” of Seymour and Thomas that the tree-width of a finite graph is exactly one less than the largest order of its brambles..

A similar Poincar´e inequality is established in a more general setting in Ambrosio [1], which develops a general theory of functions of bounded variation taking values in a

(refer to fig. Our model category proof is preceded by the following lemma which says, roughly, that a pullback of a weak équivalence along a fibration is a weak équivalence. This

Assume tha,t a concrete ca.tegory (A, U) is a small-based category with enough implicit operations. This is a consequence of the fact that the class of 7~-algebras

Their proof is based on the following result: a barreled metrizable space is not the union of an increasing sequence of closed absolutely convex.. nowhere dense

In this paper, we present a new proof of the celebrated theorem of Kellerer, stating that every integrable process, which increases in the convex order, has the same

Using, on the one side, a general result in linear algebra due to Klingenberg (see [Kli54]) and on the other side, a theorem on the holonomy of pseudo-Riemannian ma- nifolds

The roots f 1 , f 2 of the derivative polynomial are situated in the interior of the triangle abc and they have an interesting geometric property: f 1 and f 2 are the focal points