Minimal sequences in semigroups
Mohan S. Putcha · Transactions of the American Mathematical Society · 1974
In this paper we generalize a result of Tamura on δ \delta -indecomposable semigroups. Based on this, the concept of a minimal sequence between two points, and from a point to another, is introduced. The relationship between two minimal sequences between the same points is studied. The rank of a semigroup S is defined to be the supremum of the lengths of the minimal sequences between points in S . The semirank of a semigroup S is defined to be the supremum of the lengths of the minimal sequences from a point to another in S . Rank and semirank are further studied.