%0 Journal Article %A Jane Day %T Monotone relations which preserve arcs and acyclicity %J Fundamenta Mathematicae %D 1966 %P 59-65 %V 58 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/fm-58-1-59-65/ %R 10.4064/fm-58-1-59-65 %G en %F 10_4064_fm_58_1_59_65