==> main.fstb MAY NOT TERMINATE. 

Cycle with transition(s):

t3 [A = 0, B = 0, C = 1, D = 0, A__o = 1, B__o = 0, C__o = 0, D__o = 0]
 -> t5 [A = 0, B = 0, C = 1, D = 0, A__o = 1, B__o = 0, C__o = 0, D__o = 0]
 -> t7 [A = 0, B = 0, C = 1, D = 0, A__o = 1, B__o = 0, C__o = 0, D__o = 0]

is likely to be an infinite loop.