0 <-> As
As <-> 0
As <-> 0
As <-> 0
As <-> 0
0 <-> Bs
0 <-> Bs
0 <-> Bs
Bs <-> 0
0 <-> Asyn
Asyn <-> 0
Asyn <-> 0
Asyn <-> 0
0 <-> Bsyn
0 <-> Bsyn
0 <-> Bsyn
Bsyn <-> 0