Adding subscripts to a variable allows that variable to mean more than one thing. In some cases it is desirable to have a variable fit into more than one of the defined variable types. Such variables are called mixed variables. This redefinition occurs automatically, but there are restrictions.
|•||If a subscript of a variable is a Level, other subscripts can be Data or Constants, but not Auxiliaries. |
|•||If a subscript is an Auxiliary, other subscripts can be Data or Constants (but not Levels).|
|•||If a subscript is an Unchangeable Constant other subscripts must also be Unchangeable Constants.|
|•||If a subscript is a Lookup other subscripts must also be Lookups.|
|•||If a subscript of a variable is not defined, you cannot use it. |
If you do define a mixed variable, the variable will typically be typed as a Level or Auxiliary (for example in the Variable tab of the Control Panel). When it is used in the computation it will be used as the appropriate type.