bold = Main text
  Liber, Caput     grey = Comment text

1     Not,       1|         elementa here and in 39 (αρχαι and στοιχεια) convertible
2     Not,       1|        elements στοιχεια but not αρχαι, which term would be reserved
3     Not,       1|      seems to be a ref. to those αρχαι της αποδειξεως of Arist.
4     Not,       2| naturally incapable of proof, so αρχαι in Gk. Digitum: cf. 58,
5     Not,       2|          after which he made two αρχαι, θερμον και ψυχρον τουτων