NOTATION

xv

Tm

denotes the representation of {S&)m associated with the representation

r o f «. (§5.1)

ML, MR, MJ denote the minimal conditions on the set of principal left,

right, two-sided ideals, respectively, of a semigroup. (A partially ordered

set P is said to satisfy the minimal condition if each non-empty subset A

of P contains at least one minimal element, i.e., an element x of A such

that yx(yeP) implies y$A.) (§§5.3, 5.4)