%0 Journal Article %A Hartmut Höpft %T A normal form for some semigroups generated by idempotents %J Fundamenta Mathematicae %D 1974 %P 75-78 %V 84 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/fm-84-1-75-78/ %R 10.4064/fm-84-1-75-78 %G en %F 10_4064_fm_84_1_75_78