“…but it is necessary to add additional constraints, for example we can set ϕ H 2 (Ω) ≤ ρ 1 and ψ H 2 (Ω) ≤ ρ 1 which means that both ϕ and ψ are contained in the ball B H 2 (0, ρ 1 ) of center 0 and radius ρ 1 large enough (see Bergounioux et al [8]), for example, we can suppose that U ad = U ad ∩ B H 2 (0, ρ 1 ), where U ad = {(ϕ, ψ) ∈ U × U | ϕ ≤ ψ}, and U = H 2 (Ω) × H 1 0 (Ω). According to the result given in [18] the authors point out that, in spite of the elimination of the inequality constraint given by (6), we still get a local convergence property implied by the constraint ϕ n H 2 (Ω) ≤ R, where R is a positive radius large enough and ϕ n is an iterative solution (see [18]), hence, we are again confronted with the inequality constraint (6).…”