¿    Variables
   Implicit definition
   
 •   it is a good practice to explicitly define all variables
                 used in your program
 •   Variables that are assigned values but not defined will
                be assumed to be of REAL type unless the variable
                name starts with  any of  the following letters:
   
            I             J             K             L             M             N
 •   if the variable name starts with
        I             J            K             L             M             N
        and not defined , it will be assumed as INTEGER