“…According to [25], there exists a control v ∈ L 2 (0, T; L 2 (Ω) such that the corresponding solution z v of the system (1) verifies z v (T) = z d . Then, according to Theorem 5 there exists a control u * ∈ L 2 (0, T, R), which guarantees the exact attainability of z d at time T, and is a solution of the problem (P) with U ad = {u ∈ L 2 (0, T, L 2 (Ω)) /z(T) = z d }.…”