Xiàhóu Yáng 夏侯陽
Sui-period mathematician; birth and death years not securely recorded. The Sìkù 提要 of KR3f0038 Xiàhóu Yáng suànjīng establishes him as a Sui-period scholar (post-Zhēn Luán, pre-Tang) on internal-textual evidence: his preface refers to Zhēn Luán and Liú Huī as predecessors whose work was already complete; the work uses Sui institutional terminology (the cāngkù lìng granary regulations, the fùyì lìng labor regulations, the Tiánlìng land regulations) consistent with Sui-period administrative practice; and the work references the Liáng-period (505) and Sòng-period (425) bronze-vessel standardizations as historical precedents.
His sole surviving work is the Xiàhóu Yáng suànjīng 夏侯陽算經 (KR3f0038), in 3 juàn (originally 12 topical sections). The work is a practical-administrative mathematical handbook particularly oriented to the calculation of land taxation, labor service (kèzū / yōngdiào), grain measurement, and other government-bureau computational concerns. It is one of the Suànjīng shíshū (Ten Mathematical Classics) canonized under the Tang.