YES
Time: 0.034

Problem:
 Equations:
  
 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:
 AC-RPO Processor:
  precedence:
   h > fAC > g > a > b
  status:
   
  problem:
   Equations:
    
   TRS:
    
  Qed