Across
- 4. all members of all sets
- 7. a series of overlapping circles
- 8. when 2 sets overlap
- 9. a set within a set
Down
- 1. not A'
- 2. a whole number
- 3. something that belongs to a set
- 4. everything in all sets
- 5. a collection of items
- 6. what A,B,C,D... are