Statements: All bags are cakes. All lamps are cakes. Conclusions: I. Some lamps are bags. II. No lamp is a bag.

Bags and lamps both lie inside cakes, but nothing links bags with lamps, so neither conclusion follows on its own. The two conclusions, however, form a complementary pair about the same subject and predicate: either some lamps are bags or no lamp is a bag, and one of them must be true. So 'either I or II follows'; 'neither I nor II follows' would ignore this complementary pair.