Subject: question From: Martin.A.Arkowitz@Dartmouth.EDU (Martin A. Arkowitz) Date: 16 Oct 2005 18:24:16 EDT Let Z be the mapping cone of a map X-->Y. Then there is the Barratt-Puppe sequence X-->Y-->Z-->Sigma(X)-->... and an operation of [Sigma(X),V] on [Z,V] for any space V. Apart from certain obvious situations (eg, V an H-space or f the inclusion of X in the cone on X), does anyone know of concrete calculations of the operation in specific cases? For instance, what is the orbit or stability group of a non-trivial element in [Z,V]?