On the Structure of π-Left Zero Semigroups and Their Lattice of Congruences
Luo Xiao-qiang · Sichuan University of Arts and Science Journal · 2007
In this paper,the author discusses the structure of π-left zero semi-groups,to prove that if S is a finite π-left zero semi-groups such that |E(s)|≤4,then the lattice of congruences C(S) of S is a semi-modular lattice.