MAYBE
Input TRS:
      1: a(x1) -> x1
      2: a(x1) -> b(x1)
      3: a(c(x1)) -> c(c(a(b(x1))))
      4: b(b(x1)) -> a(x1)
Number of strict rules: 4
Direct POLO(bPol) ... failed.
Uncurrying ... failed.
Dependency Pairs:
     #1: #a(x1) -> #b(x1)
     #2: #a(c(x1)) -> #a(b(x1))
     #3: #a(c(x1)) -> #b(x1)
     #4: #b(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.