%0 Journal Article %A Robin Harte %A %T An index formula for chains %J Studia Mathematica %D 1995 %P 283-294 %V 116 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/sm-116-3-283-294/ %R 10.4064/sm-116-3-283-294 %G fr %F 10_4064_sm_116_3_283_294