“…Proof. For system (12), define V 1 , V 2 , and V 3 as before and assume that there exists a number δ > 0 such that sup t≥τ |x i (s)| < δ, i � 1, 2, 3. By the Itô formula, we calculate LV 1 , LV 2 , and LV 3 along system (12), respectively, then x 2 3 (s)ds,…”