“…Proof. According to Remark 4.2 in [2], pro-π k (X, X 0 , x 0 ) is a zero-object in pro-Grp (pro-Set in case k = 1) when π * k (X, X 0 , x 0 ) = 0, for k ∈ N, and then, by Lemma 5.5 in [4], pro-π * k (X, X 0 , x 0 ) is a zero-object in pro-Grp. The conditions of Theorem 3.3 are fulfilled, so ( H1), ( H2) and ( H3) hold.…”