In this paper,we investigate the properties of strongly coapproximation in normed linear spaces and lo- cally,convex spaces.The relations between strongly coapproximation and strongly unique approximation and of the f...In this paper,we investigate the properties of strongly coapproximation in normed linear spaces and lo- cally,convex spaces.The relations between strongly coapproximation and strongly unique approximation and of the f-coapproximation and f-approximation,are also considered.展开更多
The concepts of quasi-Chebyshev and weakly-Chebyshev and σ-Chebyshev were defined [3 - 7], andas a counterpart to best approximation in normed linear spaces, best coapprozimation was introduced by Franchetti and Furi...The concepts of quasi-Chebyshev and weakly-Chebyshev and σ-Chebyshev were defined [3 - 7], andas a counterpart to best approximation in normed linear spaces, best coapprozimation was introduced by Franchetti and Furi^[1]. In this research, we shall define τ-Chebyshev subspaces and τ-cochebyshev subspaces of a Banach space, in which the property τ is compact or weakly-compact, respectively. A set of necessary and sufficient theorems under which a subspace is τ-Chebyshev is defined.展开更多
文摘In this paper,we investigate the properties of strongly coapproximation in normed linear spaces and lo- cally,convex spaces.The relations between strongly coapproximation and strongly unique approximation and of the f-coapproximation and f-approximation,are also considered.
文摘The concepts of quasi-Chebyshev and weakly-Chebyshev and σ-Chebyshev were defined [3 - 7], andas a counterpart to best approximation in normed linear spaces, best coapprozimation was introduced by Franchetti and Furi^[1]. In this research, we shall define τ-Chebyshev subspaces and τ-cochebyshev subspaces of a Banach space, in which the property τ is compact or weakly-compact, respectively. A set of necessary and sufficient theorems under which a subspace is τ-Chebyshev is defined.
