I've been trying to think of the grammatically correct way to translate A[itex]\cup[/itex]B and A[itex]\cap[/itex]B. So, let's say A is the set of all animals and B is the set of all boats. Then, A[itex]\cup[/itex]B is the set of all entities which are either animals or boats (or both). And A[itex]\cap[/itex]B is the set of entities which are both animals and boats. I'm wondering if there's any ambiguity in my translation now that I've used very precise wording. What do you think?