Spaces of the same clone type

Cancellation Law for Infinite Complexes

“…Although the calculation of a homotopy set [ i L(I, J ), S i+3 ] is difficult, it is comparatively easy to calculate the homotopy set Ph( i L(I, J ), S i+3 ) of phantom maps. Now we state our results of [6,7]. By making use of these theorems, we studied cancellation and non-cancellation phenomena under the wedge sum operation in the homotopy category.…”