%0 Journal Article %A Goralčík, P. %A Goralčíková, A. %A Koubek, V. %T How much semigroup structure is needed to encode graphs ? %J RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications %D 1986 %P 191-206 %V 20 %N 2 %I AFCET - Gauthier-Villars %C Paris %U http://archive.numdam.org/item/ITA_1986__20_2_191_0/ %G en %F ITA_1986__20_2_191_0