two-level algorithm; overcorrection; multigrid algorithm; convergence; efficiency
In this paper we analyse an algorithm which is a modification of the so-called two-level algorithm with overcorrection, published in . We illustrate the efficiency of this algorithm by a model example.
 R. Blaheta: A multilevel method with correction by aggregation for solving discrete elliptic problems
. Apl. Mat. 31 (1986), 365-378. MR 0863032
 R. Blaheta: Iterative methods for numerical solving of the boundary value problems of elasticity. Thesis, Ostrava, 1987.
 S. Míka P. Vaněk: The acceleration of a two-level algebraic algorithm by aggregation in smoothing process. Appl. Mat., to appear.