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