Sets
Writing A = {1, 2, 3, 4 } means that the elements of the set A are the numbers 1, 2, 3 and 4. Sets of elements of A, for example {1, 2}, are subsets of A.
Sets can themselves be elements. For example consider the set B = {1, 2, {3, 4}}. The elements of B are not 1, 2, 3, and 4. Rather, there are only three elements of B, namely the numbers 1 and 2, and the set {3, 4}.
The elements of a set can be anything. For example, C = { red, green, blue }, is the set whose elements are the colors red, green and blue.
Read more about this topic: Element (mathematics)
Famous quotes containing the word sets:
“To me this world is all one continued vision of fancy or imagination, and I feel flattered when I am told so. What is it sets Homer, Virgil and Milton in so high a rank of art? Why is Bible more entertaining and instructive than any other book? Is it not because they are addressed to the imagination, which is spiritual sensation, and but mediately to the understanding or reason?”
—William Blake (1757–1827)
“Whether changes in the sibling relationship during adolescence create long-term rifts that spill over into adulthood depends upon the ability of brothers and sisters to constantly redefine their connection. Siblings either learn to accept one another as independent individuals with their own sets of values and behaviors or cling to the shadow of the brother and sister they once knew.”
—Jane Mersky Leder (20th century)
“Willing sets you free: that is the true doctrine of will and freedom—thus Zarathustra instructs you.”
—Friedrich Nietzsche (1844–1900)