LIBRARY IEEE;USE IEEE.std_logic_1164.ALL;USE IEEE.numeric_std.ALL;PACKAGE viterbi_block_pkg IS  TYPE vector_of_std_logic_vector4 IS ARRAY (NATURAL RANGE <>) OF std_logic_vector(3 DOWNTO 0);  TYPE vector_of_std_logic_vector2 IS ARRAY (NATURAL RANGE <>) OF std_logic;END viterbi_block_pkg;