| is a set | { } | |
| is an element of | ∈ | |
| is not an element of | ∉ | |
subset | is a subset of | ⊆ |
proper subset | is a proper subset of | ⊂ |
| is not a subset of | ⊄ | |
| union | ∪ | |
| intersection | ∩ | |
| the empty set | ∅ | |
proper superset | is a superset of | ⊇ |
superset | is a proper superset of | ⊃ |
Venn Diagram f(1) = 1 f(2) = 3 f(3) = 7 f(4) = 15 formula: f(1) = 1 f(n) = f(n-1) * 2 + 1