Turka T. The structure of semigroups of correspondences

There has been proved the theorem on the order of semigroups of correspondences of the finite group, there have been described the structure of the center of semigroup of correspondences, two natural partial orders on the semigroup of correspondences. There has been described Green's relations with semigroups of correspondences of the finite group, there have been described the main ideals of semigroup of correspondences of the eventual group. There has been proved the theorem on the structure of idempotents of semigroups of correspondences of the finite group. There has been described the structure of maximal sub-group for every idempotent which corresponds to this idempotent.