“…Based on the results in [31–33], a general solution to GHSE (20) is given by where is an arbitrary parameter matrix. Lemma Given the DHQ systems (1a) and (1b) satisfying Assumptions 1–4, let and be a pair of polynomial matrices satisfying RCF (21). Based on the results in [19, 26], there also exists a pair of polynomial matrices and for the ADHQ systems (4a) and (4b) such that …”