In this paper we describe a method of calculation of master integrals based
on the solution of systems of difference equations in one variable. Various
explicit examples are given, as well as the generalization to arbitrary
diagrams.Comment: LaTex, 10 pages, uses appolb.cls. Presented at the XXVII
International Conference of Theoretical Physics "Matter to the Deepest",
Ustron, Poland, 15-21 September 2003. To appear in Acta Physica Polonica.
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