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:
“A horse, a buggy and several sets of harness, valued in all at about $250, were stolen last night from the stable of Howard Quinlan, near Kingsville. The county police are at work on the case, but so far no trace of either thieves or booty has been found.”
—H.L. (Henry Lewis)
“It is mediocrity which makes laws and sets mantraps and spring-guns in the realm of free song, saying thus far shalt thou go and no further.”
—James Russell Lowell (1819–91)
“Willing sets you free: that is the true doctrine of will and freedom—thus Zarathustra instructs you.”
—Friedrich Nietzsche (1844–1900)