“…Under the condition that Assumption holds at each time t , it is trivial to show that and V 1 ( y ) = 0 if and only if y 1 = y 2 = ⋯ = y n = 0 from the facts that and min i = 0,1, ⋯ , n { y i } ⩽ 0. Motivated by , we construct the following sets , . Following a similar analysis as in the proof of Theorem of , we can show that, under the condition that Assumption holds at each time t , …”