MAYBE
Time: 1.078

Problem:
 Equations:
  fAC(fAC(x0,x1),x2) -> fAC(x0,fAC(x1,x2))
  fAC(x0,x1) -> fAC(x1,x0)
  fAC(x0,fAC(x1,x2)) -> fAC(fAC(x0,x1),x2)
  fAC(x1,x0) -> fAC(x0,x1)
 TRS:
  fAC(g(fAC(h(a()),a())),a()) -> fAC(h(a()),fAC(a(),a()))
  fAC(h(a()),g(a())) -> fAC(g(h(a())),a())
  fAC(g(h(a())),fAC(b(),fAC(b(),b()))) -> fAC(g(fAC(h(a()),a())),a())
  fAC(h(a()),a()) -> fAC(h(a()),b())

Proof:
 Open