downto                   Allows FOR Loops to Count Backward

 for <index> := <start> downto <finish> do
   <statement>;

    The DOWNTO keyword is used when you want the index variable (<index>)
    in a FOR loop to be decremented (going from a high to a low value). If
    <start> is less than <finish>, then <statement> is never executed.

         <index>    Any declared ordinal (Integer, Char, Boolean,
                    enumerated) variable.

<start>,<finish>    Any expression of the same type as <index>.

     <statement>    Any legal statement; for multiple statements, use a
                    compound statement.

  -------------------------------- Example ---------------------------------

           for I := 25 downto 17 do
             writeln(I);

           for Ch := 'Z' downto 'A' do
             writeln(Ch);