MAYBE
Input TRS:
      1: c(c(c(a(x1)))) -> d(d(x1))
      2: d(b(x1)) -> c(c(x1))
      3: b(c(x1)) -> b(a(c(x1)))
      4: c(x1) -> a(a(x1))
      5: d(x1) -> b(c(x1))
Number of strict rules: 5
Direct POLO(bPol) ... removes: 4
      a 	w: x1
      d 	w: x1 + 17562
      b 	w: x1 + 5854
      c 	w: x1 + 11708
Number of strict rules: 4
Direct POLO(bPol) ... failed.
Uncurrying ... failed.
Dependency Pairs:
     #1: #d(b(x1)) -> #c(c(x1))
     #2: #d(b(x1)) -> #c(x1)
     #3: #d(x1) -> #b(c(x1))
     #4: #d(x1) -> #c(x1)
     #5: #b(c(x1)) -> #b(a(c(x1)))
     #6: #c(c(c(a(x1)))) -> #d(d(x1))
     #7: #c(c(c(a(x1)))) -> #d(x1)
Number of SCCs: 1, DPs: 5
  SCC { #1 #2 #4 #6 #7 }
POLO(Sum)... succeeded.
      a 	w: x1
      d 	w: x1 + 31353
      b 	w: x1 + 10451
      c 	w: x1 + 20902
      #d 	w: x1 + 10451
      #c 	w: x1
      #b 	w: 0
    USABLE RULES: { 1..3 5 }
    Removed DPs: #2 #4 #7
Number of SCCs: 1, DPs: 2
  SCC { #1 #6 }
POLO(Sum)... POLO(max)... QLPOS... POLO(mSum)... QWPOpS(mSum)... Mat2b... failed.
Finding a loop...  failed.