《资治通鉴·晋纪·晋纪二十九》
于是杨定便自称为秦州牧、陇西王。前秦后来也就按照他所自称的，委任他官职。
定自称秦州牧、陇西王，秦因其所称而授之。
So Yang Ding claimed himself to be the governor of Qinzhou and king of Longxi. Former Qin later followed his claim and appointed him.