I'm about ready to pull my hair out! For the following code:
library BITLIB;
use BITLIB.bit_apack.all;
entity COUNTER is
port (a, b, c, d: in bit; x, y, z: out bit);
end entity;
architecture COUNT of COUNTER is
signal na, nb, nc, nd: bit;
begin
na <= NOT a;
nb <= NOT b;
nc <=...