library ieee;
use ieee.std_logic_1164.all;
package mypack is 
function max (a,b: std_logic_vector)
         return std_logic_vector;
end ;
PACKAGE body mypack IS
     function max (a,b: std_logic_vector)
               return std_logic_vector is
begin
   if(a>b)THEN
         return a;
      ELSE
        return b;
   END IF;
       end ;
   end ;