A. A. Mironov ,   V. I. Tsurkov Computer and Systems Sciences International , Vol.38 No.6 , 01.1999 , p. 933-940, language: английский ISSN 1064-2307  Аннотация A pair of vectors with a nonascending coordinate order is called extremal if it determines a unique transport matrix consisting of zeros and units; the latter is also called extremal. Any transport pair of vectors can be represented, as a convex combination of extremal pairs up to a permutation of coordinates and up to a multiplier. For the sets of extremal pairs of vectors and extremal matrices of the same dimension, two binary operations and metrics are introduced on both of them, with respect to which, these sets are isomorphic distrib- utive lattices and isometric spaces. The duality principle for lattices is applied to problems of linear program- ming.  Ключевые слова extremal matrices and vectors, metric, linear programming, transportation problems