“…By the S-procedure, if (15) holds with P ≻ 0 and τ1 , τ2 , and τ3 nonnegative, then σ (1) 0 (𝜉(k)) ≥ 0 whenever σ1 (𝜉(k)) ≥ 0, σ2 (𝜉(k)) ≥ 0, and σ3 (𝜉(k)) ≥ 0. Similarly, if (16) holds with P ≻ 0, Q ≻ 0, and τ4 , τ5 , and τ6 nonnegative, then σ (2) 0 (𝜉(k)) ≥ 0 whenever σ1 (𝜉(k)) ≥ 0, σ2 (𝜉(k)) ≥ 0, and σ3 (𝜉(k)) ≥ 0. To conclude, σ2 (𝜉(k)) ≥ 0 since 𝚫 ∈ pwIQC(Ψ, S), σ3 (𝜉(k)) ≥ 0 since d(k) ∈ Λ , and σ1 (𝜉(k)) ≥ 0 by assumption.…”