NOTA  1->0
SIGX  AT  0  IF  1T
NOTA  0->1
SIGX  AT  1  IF  0T
NOTA  2->0
SIGX  AT  0  IF  2T
NOTA  0->2
SIGX  AT  2  IF  0T
NOTA  3->0
SIGX  AT  0  IF  3T
NOTA  0->3
SIGX  AT  3  IF  0T
