V. I. Tsurkov Autom. Remote Control , 41 , 01.1980 , p. 408-415, language: английский ISSN 0005-1179  Аннотация A decomposition method is proposed for finding extremal element of some class of systems. We suppose that some part of connections in the ssytem has the block-diagonal structure, while the oter part as well as the criterion is block separable. Decomposition employs aggregation of variables and uses duality principles.  Ключевые слова decomposition of functional systems; aggregation of variables; duality principles