theorem Th25:
  UsedILoc I = UsedILoc Reloc(I, k)
proof
A1:  Reloc(I,k) = IncAddr(Shift(I,k),k) by COMPOS_1:34;
  UsedILoc Reloc(I, k) = UsedILoc Shift (I, k) by Th24,A1
    .= UsedILoc I by Th22;
  hence thesis;
end;
