P0 -> P1
T0 -> T1
P1 -> P0
T1 -> T0
P1 -> P2
T1 -> T2
P2 -> P1
T2 -> T1
P0 -> 0
T0 -> 0
P1 -> 0
T1 -> 0
P2 -> 0
T2 -> 0
P2 + T2 <-> CC
CC <-> Cn
CC -> 0
Cn -> 0
0 -> Mp
0 -> Mt
0 -> P0
0 -> T0
Mp -> 0
Mt -> 0