For any set S and any object x, either x is a member of S or it is not.
In order to indicate that x is a member of S,
we write
x S
x S is a shorthand for: x is a member of S.
In order to indicate that x is not a member of S,
we write
x S
x S is a shorthand for: x is not a member of S.
Examples: The following are true statements
Last modified: 27/July/98 (12:14)