this again is talking about a set S whose elements are sets. any element that is in the union of all the sets will be in , that is any element that is in ANY set will be in the setfor any non-empty set S
denotes the set
I've never actually seen these represented using Venn Diagrams, but it may be possible. In the class I took we used a kind of number line approachCan it be explain using Venn Daigaram?