Element (mathematics)

In mathematics, an element (or member) of a set is any one of the distinct objects that belong to that set. For example, given a set called containing the first four positive integers ($A\; =\; \backslash \{1,\; 2,\; 3,\; 4\backslash \}$), one could say that "3 is an element of ", expressed notationally as $3\; \backslash in\; A$. Provided by Wikipedia