The chains of left strongly simple
semigroups are also characterized. There is an essential difference between
semigroups without order and ordered semigroups. While the decomposition of
a semigroup (without order) into archimedean (or left strongly simple) components
is unique, the decomposition of an ordered semigroup into archimedean
(or left strongly simple) components is not unique in general.
Suppose S is a semilattice of left strongly simple semigroups and that σ
is a semilattice congruence on S such that (x)σ is a left strongly simple sub