Ertuğrul, Z.Kocatepe, Mefharet2020-11-092020-11-0919951300-0098http://hdl.handle.net/11693/54449In this note, we study the relationship between the vanishing of the functor Ext (Ex F, E x F) for two Kothe spaces E and F, one of which having property (DN), and the existence of a pseudo-regular basis in the space Ex F and E®"F.EnglishArticle