“…Additionally, V1 → −∞ as θ → 2. This along with the fact that V 1 → ∞ whenever θ → 2 and ∇z c > µ 1 > 0, implies that D 1 is a forward invariant set, and thus θ ∈ [0, 2) for all t. For the forced system f (t, θ, δ), we obtain (35) where 1 . Therefore, using Definition 3.3 of local input-to-state stability in [15], and according to Theorem 4.19 in [23], the origin of the forced system f (t, θ, δ) is locally input-to-state stable.…”