SUBRANGES
Just as you can create your own set of pre-defined data types, you can also create a smaller subset or subrange of an existing set which has been previously defined. Each subrange consists of a defined lower and upper limit. Consider the following,

	type DAY = (Monday,Tuesday,Wednesday,Thursday,Friday,Saturday,Sunday);
	     Weekday = Monday..Friday;     {subrange of DAY}
	     Weekend = Saturday..Sunday;   {subrange of DAY}
	     Hours   = 0..24;              {subrange of integers}
	     Capitals= 'A'..'Z';           {subrange of characters)

	NOTE: You cannot have subranges of type real.

	type  Gradepoints = 0.0..4.0;
	      Numbers = integer;
	      Alphabet = 'Z'..'A';