%0 Journal Article %A Knast, Robert %T A semigroup characterization of dot-depth one languages %J RAIRO. Informatique théorique %D 1983 %P 321-330 %V 17 %N 4 %I EDP-Sciences %U http://www.numdam.org/item/ITA_1983__17_4_321_0/ %G en %F ITA_1983__17_4_321_0