Preconditioners are often used to accelerate the convergence of iterative methods. In this paper the authors present two preconditioning techniques for systems of equations, where the coefficient matrix is a so-called $L$ matrix. The preconditioners are used to accelerate the successive over relaxation (SOR) method and convergence of the resulting iterative method is analyzed. Numerical results are presented that support the theoretical results of this paper.
Reviewer: Robert F. Remis (Delft)