MAYBE
Time: 0.016

Problem:
 Equations:
  +AC(+AC(x3,x4),x5) -> +AC(x3,+AC(x4,x5))
  +AC(x3,x4) -> +AC(x4,x3)
  +AC(x3,+AC(x4,x5)) -> +AC(+AC(x3,x4),x5)
  +AC(x4,x3) -> +AC(x3,x4)
 TRS:
  +AC(f(b()),g(a())) -> +AC(f(a()),g(b()))
  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