“…In the following theorem, we will study the relationship between K |Ω GV |,|Ω B | (A(Ω GV ), B(Ω B )) and K |Ω QS |,|Ω B | (A(Ω QS ), B(Ω B )). The similar conclusions had been obtained for eigenvalue, generalized eigenvalue computations and linear system solving for {1;1}-quasiseparable matrices in [11,16,17], respectively. Before that, we need to review Lemma 5.1, which describes the perturbation magnitude relationship between the Givens-vector representation via tangents given in Definition 2.3 and the quasiseparable representation given in Definition 2.1.…”