library ieee;
use ieee.std_logic_1164.all;

package my_utilities is

function inc(s : std_logic_vector) return std_logic_vector;

function dec(s : std_logic_vector) return std_logic_vector;

end my_utilities;

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_arith.all;
use ieee.std_logic_unsigned.all;

package body my_utilities is

function inc(s : std_logic_vector) return std_logic_vector is
begin
    return s + 1;
end;

function dec(s : std_logic_vector) return std_logic_vector is
begin
    return s - 1;
end;

end my_utilities;