“…A set K ⊂ Z is τ -relatively compact if the following three conditions hold:(a) ∀u ∈ K and all t ∈ [0, T ], u(t) ∈ L 2 (O) and sup u∈K sup s∈[0,T ] u(s) L 2 < ∞, ds < ∞, i.e. K is bounded in L 2 (0, T ; H 1 0 (O)), (c) lim δ→0 sup u∈K w [0,T ],H −1 (O) (u, δ) = 0.For proof see Lemma 3.3 in[11], Lemma 4.1 in[36], Theorem 2 of[37], Lemma 2.7 in[35] …”