This is the final part of the translation in this series of Ammonius’ commentary on Aristotle On Interpretation. This is the only commentary written out and published by Ammonius, teacher of the philosophers Philoponus, Simplicius, Asclepius and Olympiodorus. Ammonius based his commentary on the lectures of Proclus, which he supplemented with material from the copious commentary of Porphyry, which was also a main source of Boethius’ commentary, and the commentary of Proclus’ teacher Syrianus. A major contribution of Ammonius’ own was his demonstration that On Interpretation was a finished and coherent work of philosophy, not a set of notes.