You can create your own variables and change their values. When using
        variables, the following guidelines apply:
          - Variable names are case insensitive and are limited to 32
            characters.
 
          - The variable name must be unique.
 
          - A variable can be referenced as $X or
            $(X).
 
          - If a variable already exists, it is overwritten. No error message
            is displayed.
 
          - The variable expression can be a constant value, another variable,
            or a combination of the above with operators and functions. Operators are described in ,
            and functions are described in .
 
          - Only the set var
            command supports expression evaluation.
 
          - If the variable name X contains special characters such as +-/*,
            then the variable needs to be enclosed in parentheses. For example: set var z ($(x) +
            100).
 
          - When you use a variable with a TCL special character in the $TCL
            function, the variable must be enclosed in braces. For example: set var x $TCL(string
            length ${CLI.USER}.
 
          - For more information on TCL functions,
            see Using Built-In Functions.

Note   
ExtremeXOS does not
              consider the dot/period character as a de-limiter. This is different from standard TCL
              behavior, where dot/period is considered as a de-limiter.