reserve j, k, m for Nat;

theorem
  for II, I being Instruction of SCM, k being Element of NAT st (
InsCode I = 0 or ... or InsCode I = 5) & IncAddr (II, k) = I holds II = I
proof
  let II, I be Instruction of SCM, k be Element of NAT;
  assume that
A1: InsCode I = 0 or ... or InsCode I = 5 and
A2: IncAddr (II, k) = I;
   IncAddr(I,k) = I by A1,Th4;
  hence thesis by A2,COMPOS_0:6;
end;
