We provide an elementary proof of a result by V. P. Fonf and C. Zanco on point-finite coverings separable Hilbert spaces. Indeed, using variation the famous argument introduced J. Lindenstrauss R. Phelps [Israel Math. 6 (1968), pp. 39–48] to prove that unit ball reflexive infinite-dimensional Banach space has uncountably many extreme points, we following result. Let <inline-formula cont...

Abstract In this work a multi-point constraint unfitted finite element method for the solution of Poisson equation is presented. Key features approach are strong enforcement essential boundary, and interface conditions. This, along with stability method, achieved through use constraints that applied to so-called ghost nodes lie outside physical domain. Another key benefit lies in fact that, as ...

Abstract For a probability measure μ on [0, 1] without discrete component, the best possible order of approximation by finite point set in terms star-discrepancy is &amp;inline as has been proven relatively recently. However, if contains component no non-trivial lower bound holds general because it straightforward to construct examples any error this case. This might explain, why measures sets ...