Qīng Yìxué scholar of Sānyuán 三原 (Shǎnxī), author of Zhōuyì xiángshuō 周易詳説 — a substantial close commentary on the Yì that is influential as a source for the Sìkù tíyào treatment of the Sòng yìlǐ tradition. He is repeatedly cited by the Sìkù editors for his observation that 程頤 Chéng Yí’s Yìzhuàn substantively derives from 胡瑗 Hú Yuán’s classroom teaching rather than from the canonical 周敦頤 Zhōu Dūnyí → Chéng-brother lineage that 朱熹 Zhū Xī later codified.