 (iii) The above pairs (per se 1 and 2, and containment and necessary implication) are associated with a further distinction between two types of inseparability. The theme is developed by Avicenna especially in connection with the Isagoge, most notably in Madḫal I.5, I.6, and I.8. The first type is conceptual inseparability (the counterpart of per se 1 and containment); the second type is inseparability in imagination (the counterpart of per se 2 and necessary implication) (Strobino 2016b).