Commutative Semigroups

General structure theory. - I. Elementary properties. - II. Cancellative semigroups. - III. Semilattice decompositions. - IV. Subdirect decompositions. - V. Group coextensions. - VI. Finitely generated semigroups. - VII. Subcomplete semigroups. - VIII. Other results. - Congruences. - IX. Nilsemigroups. - X. Group-free semigroups. - XI. Subcomplete semigroups. - Cohomology. - XII. Commutative semigroup cohomology. - XIII. The overpath method. - XIV. Semigroups with zero cohomology. - References. - Author Index. - Notation. Language: English