 Kilwardby explains that in first-figure mixed necessity-assertoric syllogisms the necessity premise appropriates to itself a minor which is necessary per se; no such appropriation occurs in first-figure mixed assertoric-necessity syllogisms. There are similar appropriation rules for some mixed second-figure and third-figure moods with assertoric and necessity premises and for various mixed contingency moods pertaining to the kind of appropriated contingency premises or assertoric premises (Thom 2007, chs. 5–6).