RT Journal T1 Unipotent congruences on a proper weakly left type B semigroup A1 LI Chun-hua, XU Bao-gen, HUANG Hua-wei PB JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE) FD 2016-08-20 YR 2016 JF JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE) JO JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE) VO 51 IS 8 SP 49 DO 10.6040/j.issn.1671-9352.0.2015.248 K1 weakly left type B semigroups;proper;unipotent congruences;structure mappings LK {http://lxbwk.njournal.sdu.edu.cn/EN/article/article_2115.shtml}