“…For any , let us define
and
Then from Lemma 2.2 it follows that and are both pairwise NQD, and
Furthermore, let us define , then the limit (2.2) holds if we show
and
Using the proof of Lemma 2.2 in [4], we get
and
From Lemma 2.1 and Lemma 2.3, we have
which implies (2.6). Similarly, for any , we have
which yields (2.7).…”