MAYBE
Input TRS:
      1: a(b(c(x1))) -> b(x1)
      2: c(b(b(x1))) -> a(x1)
      3: c(x1) -> b(x1)
      4: a(a(x1)) -> c(b(a(c(x1))))
Number of strict rules: 4
Direct POLO(bPol) ... removes: 1
      a 	w: x1 + 35397
      b 	w: x1 + 11799
      c 	w: x1 + 11799
Number of strict rules: 3
Direct POLO(bPol) ... failed.
Uncurrying ... failed.
Dependency Pairs:
     #1: #c(b(b(x1))) -> #a(x1)
     #2: #a(a(x1)) -> #c(b(a(c(x1))))
     #3: #a(a(x1)) -> #a(c(x1))
     #4: #a(a(x1)) -> #c(x1)
Number of SCCs: 1, DPs: 4
  SCC { #1..4 }
POLO(Sum)... succeeded.
      a 	w: x1 + 26568
      b 	w: x1 + 8856
      c 	w: x1 + 8856
      #c 	w: x1
      #a 	w: x1 + 17712
    USABLE RULES: { 2..4 }
    Removed DPs: #3 #4
Number of SCCs: 1, DPs: 2
  SCC { #1 #2 }
POLO(Sum)... POLO(max)... QLPOS... POLO(mSum)... QWPOpS(mSum)... Mat2b... failed.
Finding a loop...  failed.