YES
Input TRS:
    1: h(x) -> a()
    2: g(x) -> x
    3: g(x) -> a() | h(x) --> b()
    4: c() -> c()
Infeasibility test:
    h(x) --> b()
Symbol transition graph:
    h	--> a
    c	--> c
    g	-->  # a b c g h
  Collapsable symbols: { g }