 One work of Ammonius clearly survives in the written form he gave it, his ‘commentary’ (hupomnēma) on Aristotle’s De Interpretatione. His commentary on Porphyry’s Introduction (in Isag.), is described in the manuscripts variously as ‘Ammonius the Philosopher’s Exegesis (or Prolegomena or Commentary) of the Five Sayings’ and is perhaps another work given its final form by Ammonius; but its present Prooemium is, in any case, considered inauthentic, and other passages are also interpolations (Busse, CAG IV.3 p. vi).