--  Types, and functions:
   type BitArray32 is ...
   function INT_TO_BITARRAY32 is new unchecked_conversion(Integer, BitArray32);

   function swap_nibbles(x: BitArray32) return BitArray32 is ... --  Assume it exists

   subtype Str4 is String(1 .. 4)
   function BITARRAY32_TO_STR4 is new unchecked_conversion(BITARRAY32, Str4);


   --  DATAFLOW: Values are shown indented, in various forms.
   --     Data transformations are shown in column 1

   One of the integers from the file decode2.txt, 
      8 ASCII characters, as rendered by editor:
         43308546

      64 bits show how that number is actually stored in the file (spaces added for readability):
         0011 0100 0011 0011 0011 0011 0011 0000 0011 1000 0011 0101 0011 1001 0011 0110
      hex version of bits that are stored:
         34 33 33 30 38 35 34 36


   i: Integer
GET(i)

   Contents of i: 
      32 bits that are actually stored (spaces added for readability):
         0000 0010 1001 0100 1101 0110 0000 0010 
      hex version of bits that are stored
         02 94 D6 02 


b: BitArray32 := INT_TO_BITARRAY32(i);

   Contents of b: 
      32 bits that are actually stored (spaces added for readability):
         0000 0010 1001 0100 1101 0110 0000 0010 
      hex version of bits that are stored
         02 94 D6 02 

c: BitArray32 := swap_nibbles(b);  --  Assume it exists

   Contents of c: 
      32 bits that are actually stored (spaces added for readability):
        0010  0000 0100 1001 0110 1101 0010 0000 
      hex version of bits that are stored
         20 49 6D 20 

s4: Str4 := BITARRAY32_TO_STR4(i)

   Contents of s4 (which are identical to i at the bit level)
      32 bits that are actually stored (spaces added for readability):
         0010 0000 0100 1001 0110 1101 0010 0000
      hex version of bits that are stored
         20 49 6D 20 

PUT("<" & s4 & ">");
   Output from put command (ie printed as string with <&gt; to show blanks):
         < Im >