| In this paper,we study some properties of (f-) coapproximation and strongly (f-) coapproximation in locally convex spaces and normed linear spaces. The characterization theorems of (f-) coapproximation, strongly (f-) coapproximation, and strongly (f-) Kol-mogorov set in locally convex spaces are obtained. Meanwhile, we give two examples to show that two main theorems of G. S. Rao do not hold, and then establish the corresponding correct results, parts of our results extend and improve the corresponding results due to Song、Rao、Narang and other authors. |
