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