Given: All Zams are Bams, All Bams are Bings, All Zams are Zings. This means Zams are a subset of Bams, which are a subset of Bings. Zams are also a subset of Zings. Since Zams exist and are both Bings and Zings, there must be some overlap between Bings and Zings (at minimum, the Zams themselves are both). However, we don't know if ALL Zings are Bings or if some Zings aren't Bams.