 Boethius also wrote a commentary on the Categories. This commentary was intended to be an elementary exposition of the treatise. Boethius planned to write a second exposition, addressed to more advanced students (Boethius In Cat. 160 A-B). It is just unclear whether he was able to produce this more advanced commentary. (For further information on Boethius as a commentator, see Section 2 of the entry on  Anicius Manlius Severinus Boethius.)