Chén Yuán 陳元, Eastern Hàn Yì-master in the 費直 Fèi Zhí line of transmission, between Fèi Zhí and 鄭眾 Zhèng Zhòng / 馬融 Mǎ Róng / 鄭玄 Zhèng Xuán / 王弼 Wáng Bì — the standard pre-medieval Yì-transmission line that became the canonical received recension. Cited in the Sìkù notice on KR1a0156.