... • zero-sum free if ∈ / (X), • a zero-sum sequence if σ(X) = 0, • squarefree if vg (X) for all g ∈ G, moreover, a squarefree sequence can be considered as a subset of G the electronic journal of ... the proof In this section, we present some Lemmas that will be used in the proof of the main result Lemma 5.1 Let X ⊆ G be a zero-sum free generating set of G, |X| = 4, and X has no element of order ... if In part of the Lemma, case (b) and case (c) not hold simultaneously Proof of the Theorem 1.1 Proof Let X ⊂ G be a zero-sum free subset with |X| = 7, and let S = (X) Without loss of generality,...