M. Redivo Zaglia 

      Universita degli Studi di Padova Dipartimento di
	   Matematica Pura ed Applicata, Italy


  "A Schur complement approach to a general extrapolation algorithm"

This work  is devoted to a Schur complement approach to the E-transformation
which is the most general scalar sequence transformation known so far for
accelerating the convergence. A new derivation of known results on Schur
complements is given in the first part of the paper. Then, Schur complements
and their properties are used to obtain various interpretations of the
E-transformation. The recursive rules of the E-algorithm for its
implementation are also recovered. New results on its kernel are derived and
issues on its convergence are discussed. This approach can be extended to the
vector case, thus leading to new vector sequence transformations.

This is a joint work with Claude Brezinski from University of Lille.