theorem Th6:
  for i being Element of the InstructionsF of STC N
    holds InsCode i = 1 or InsCode i = 0
proof
  let i be Element of the InstructionsF of STC N;
  the InstructionsF of STC N = III by Def7;
  then i = [1,0,0] or i = [0,0,0] by TARSKI:def 2;
  hence thesis;
end;
