Recently Sudan formulated a decoding procedure for decoding RScodes beyond the packing radius. The potential of the method for AGcodes was recognized by Shokrollahi and Wasserman. We discuss similarities and differences with some previous algebraic decoding procedures.

We investigate the stability of Fredholm properties on interpolation scales of quasi-Banach spaces. This analysis is motivated by problems arising in PDE’s and several applications are presented.

Let A be a linear bounded operator from a couple X = (X0, X1) to a couple Y = (Y0, Y1) such that the restrictions of A on the spaces X0 and X1 have bounded inverses. This condition does not imply that the restriction of A on the real interpolation space (X0, X1)θ,q has a bounded inverse for all values of the parameters θ and q. In this paper under some conditions on the kernel of A we describe ...

This paper provides some conditions to obtain best uniform coapproximation. Some error estimates are determined. A relation between interpolation and best uniform coapproximation is exhibited. Continuity properties of selections for the metric projection and the cometric projection are studied.

and Applied Analysis 3