Department of Mathematics, Faculty of Science, Okayama University Acta Medica Okayama 0030-1566 3 1 1953 Inverses in Euclidean mobs EN A. D. Wallace No potential conflict of interest relevant to this article was reported.

Department of Mathematics, Faculty of Science, Okayama University Acta Medica Okayama 0030-1566 3 1 1953 Indecomposable semigroups EN A. D. Wallace No potential conflict of interest relevant to this article was reported.