YES
Input TRS:
      1: a(a(a(x1))) -> b(b(x1))
      2: b(b(b(x1))) -> c(x1)
      3: c(x1) -> d(d(x1))
      4: d(x1) -> a(a(x1))
Number of strict rules: 4
Direct POLO(bPol) ... removes: 4 1 3 2
      a 	w: x1 + 11
      d 	w: x1 + 23
      b 	w: x1 + 16
      c 	w: x1 + 47
Number of strict rules: 0