MAYBE
Time: 0.017

Problem:
 Equations:
  
 TRS:
  +AC(f(a()),g(b())) -> +AC(f(b()),g(a()))
  k(a(),g(g(a()))) -> k(g(a()),f(a()))
  +AC(g(x),y) -> g(+AC(x,y))
  f(+AC(x,y)) -> +AC(f(x),y)
  k(a(),b()) -> k(b(),a())
  k(g(a()),a()) -> k(a(),g(b()))
  k(g(a()),b()) -> k(a(),g(a()))

Proof:
 Open