YES
Input TRS:
    1: pin(a()) -> pout(b())
    2: pin(b()) -> pout(c())
    3: tc(x) -> x
    4: tc(x) -> y | pin(x) --> pout(z()) | tc(z()) --> y
Infeasibility test:
    pin(x1) --> pout(z())
    tc(z()) --> x2
Symbol transition graph:
    tc	-->  # a b c pin pout tc z
    pin	--> pout
  Collapsable symbols: { tc tc }