Resumen de Functional characterization of best and good approximation in normed product spaces

Manuel Fernández García-Hierro , Carlos Benítez Rodríguez

• In [6], C. Dierick deals with a small but important collection of norms in the product of a finite number of normed linear spaces and he extends to such products some results on functional characterization of best approximations. In this paper we establish the widest scope in which the mentioned results remain valid.