Аннотации:
A metric space X is called h- homogeneous if IndX=0 and each nonempty open-closed subset of X is homeomorphic to X. We describe how to assign an h-homogeneous space of first category and of weight k to any strongly zero-dimensional metric space of weight ≤ k. We investigate the properties of such spaces. We show that if Q is the space of rational numbers and Y is a strongly zero-dimensional metric space, then QxYω is an h-homogeneous space and FxQxYω is homeomorphic to QxYω for any Fσ-subset F of QxYω. L. Keldysh proved that any two canonical elements of the Borel class α are homeomorphic. The last theorem is generalized for the nonseparable case. © 2010 Elsevier B.V.