The key relation between sets is membership – when one set is an element of another. If a is a member of B, this is denoted a ∈ B, while if c is not a member of B then c ∉ B. For example, with respect to the sets A = {1,2,3,4}, B = {blue, white, red}, and F = {n2 − 4 : n is an integer; and 0 ≤ n ≤ 19} defined above,
- 4 ∈ A and 285 ∈ F; but
- 9 ∉ F and green ∉ B.
Read more about this topic: Set (mathematics)
Famous quotes containing the word membership:
“The two real political parties in America are the Winners and the Losers. The people don’t acknowledge this. They claim membership in two imaginary parties, the Republicans and the Democrats, instead.”
—Kurt Vonnegut, Jr. (b. 1922)