MAYBE
Input TRS:
      1: a(a(a(b(b(x1))))) -> b(b(a(b(b(a(a(a(x1))))))))
      2: b(b(a(x1))) -> x1
      3: a(x1) -> b(b(b(x1)))
      4: a(x1) -> b(x1)
Number of strict rules: 4
Direct POLO(bPol) ... failed.
Uncurrying ... failed.
Dependency Pairs:
     #1: #a(x1) -> #b(b(b(x1)))
     #2: #a(x1) -> #b(b(x1))
     #3: #a(x1) -> #b(x1)
     #4: #a(a(a(b(b(x1))))) -> #b(b(a(b(b(a(a(a(x1))))))))
     #5: #a(a(a(b(b(x1))))) -> #b(a(b(b(a(a(a(x1)))))))
     #6: #a(a(a(b(b(x1))))) -> #a(b(b(a(a(a(x1))))))
     #7: #a(a(a(b(b(x1))))) -> #b(b(a(a(a(x1)))))
     #8: #a(a(a(b(b(x1))))) -> #b(a(a(a(x1))))
     #9: #a(a(a(b(b(x1))))) -> #a(a(a(x1)))
     #10: #a(a(a(b(b(x1))))) -> #a(a(x1))
     #11: #a(a(a(b(b(x1))))) -> #a(x1)
     #12: #a(x1) -> #b(x1)
Number of SCCs: 1, DPs: 4
  SCC { #6 #9..11 }
POLO(Sum)... POLO(max)... QLPOS... POLO(mSum)... QWPOpS(mSum)... Mat2b... failed.
Finding a loop...  failed.