title: How can you check if an element belongs to one subtype or another?
body: <p>I just learnt about Enums and Types in Ada and decided to write a small program to practice:</p>
  
  <pre><code>with Ada.Text_IO;                       use Ada.Text_IO;
  with Ada.Integer_Text_IO;       use Ada.Integer_Text_IO;
  
  procedure Day is 
  
      type Day_Of_The_Week is (Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday);
  
      subtype Weekday is Day_Of_The_Week range Monday..Friday;
  
      subtype Weekend is Day_Of_The_Week range Saturday..Sunday;
  
          function is_Weekday ( dayOfTheWeek: in Day_Of_The_Week) return Boolean is
          begin
              if(--?--)
          end is_Weekday;
  
      selected_day_value  :   Integer;
      selected_day                :   Day_Of_The_Week;
  
  begin
      Put_Line("Enter the number co-responding to the desired day of the week:");
      Put_Line("0 - Monday");
      Put_Line("1 - Tuesday");
      Put_Line("2 - Wednesday");
      Put_Line("3 - Thursday");
      Put_Line("4 - Friday");
      Put_Line("5 - Saturday");
      Put_Line("6 - Sunday");
      Get(selected_day_value);
      selected_day = Day_Of_The_Week'pos(selected_day_value);
  
      if( is_Weekday(selected_day))
          Put_Line( Day_Of_The_Week'Image(selected_day) &amp; " is a weekday." );
      else
          Put_Line( Day_Of_The_Week'Image(selected_day) &amp; " is a weekday." );
  
  end Day;
  </code></pre>
  
  <p>I'm having trouble with the if statement. How can I check whether or not dayOfTheWeek is in the Weekday subtype or the weekend subtype?</p>