Representation of discrete variables

Let us decide some conventions for use with discrete variables:

• We shall mostly deal with time as the discrete variable, and shall denote it by “n” and keep “t” for continuous time.

• We will enclose discrete variables in brackets [.] as opposed to parenthesis (.) for continuous variables.

• A discrete signal is also called a sequence - the word coming from the familiar usage in mathematics.

We shall next discuss about systems.