“…Further, it was proved by Vaserstein in [V3,Th. 4] that for A = C(X), the algebra of complex-valued continuous functions on a d-dimensional normal topological space X, E n (A) coincides with the set of null-homotopic maps, i.e., maps in SL n (A) := C(X, SL n (C)) homotopic (in this class of maps) to a constant map, and, moreover, there exists a constant v(d) ∈ N depending on d only such that sup n t n (A) ≤ v(d) (see also [DV,Lm.…”