MAYBE
Input TRS:
      1: b(b(d(d(b(b(x1)))))) -> c(c(d(d(b(b(x1))))))
      2: b(b(a(a(c(c(x1)))))) -> b(b(c(c(x1))))
      3: a(a(d(d(x1)))) -> d(d(c(c(x1))))
      4: b(b(b(b(b(b(x1)))))) -> a(a(b(b(c(c(x1))))))
      5: d(d(c(c(x1)))) -> b(b(d(d(x1))))
      6: d(d(c(c(x1)))) -> d(d(b(b(d(d(x1))))))
      7: d(d(a(a(c(c(x1)))))) -> b(b(b(b(x1))))
Number of strict rules: 7
Direct POLO(bPol) ... removes: 2
      a 	w: 2 * x1 + 8366
      d 	w: x1
      b 	w: 2 * x1 + 8366
      c 	w: 2 * x1 + 8366
Number of strict rules: 6
Direct POLO(bPol) ... failed.
Uncurrying ... failed.
Dependency Pairs:
     #1: #d(d(c(c(x1)))) -> #d(d(b(b(d(d(x1))))))
     #2: #d(d(c(c(x1)))) -> #d(b(b(d(d(x1)))))
     #3: #d(d(c(c(x1)))) -> #b(b(d(d(x1))))
     #4: #d(d(c(c(x1)))) -> #b(d(d(x1)))
     #5: #d(d(c(c(x1)))) -> #d(d(x1))
     #6: #d(d(c(c(x1)))) -> #d(x1)
     #7: #d(d(a(a(c(c(x1)))))) -> #b(b(b(b(x1))))
     #8: #d(d(a(a(c(c(x1)))))) -> #b(b(b(x1)))
     #9: #d(d(a(a(c(c(x1)))))) -> #b(b(x1))
     #10: #d(d(a(a(c(c(x1)))))) -> #b(x1)
     #11: #d(d(c(c(x1)))) -> #b(b(d(d(x1))))
     #12: #d(d(c(c(x1)))) -> #b(d(d(x1)))
     #13: #d(d(c(c(x1)))) -> #d(d(x1))
     #14: #d(d(c(c(x1)))) -> #d(x1)
     #15: #a(a(d(d(x1)))) -> #d(d(c(c(x1))))
     #16: #a(a(d(d(x1)))) -> #d(c(c(x1)))
     #17: #b(b(b(b(b(b(x1)))))) -> #a(a(b(b(c(c(x1))))))
     #18: #b(b(b(b(b(b(x1)))))) -> #a(b(b(c(c(x1)))))
     #19: #b(b(b(b(b(b(x1)))))) -> #b(b(c(c(x1))))
     #20: #b(b(b(b(b(b(x1)))))) -> #b(c(c(x1)))
Number of SCCs: 1, DPs: 5
  SCC { #1 #5 #6 #13 #14 }
POLO(Sum)... succeeded.
      a 	w: x1 + 21239
      d 	w: x1
      b 	w: x1 + 21239
      c 	w: x1 + 21239
      #d 	w: x1
      #a 	w: 0
      #b 	w: 0
    USABLE RULES: { 1 3..7 }
    Removed DPs: #5 #6 #13 #14
Number of SCCs: 1, DPs: 1
  SCC { #1 }
POLO(Sum)... POLO(max)... QLPOS... POLO(mSum)... QWPOpS(mSum)... Mat2b... failed.
Finding a loop...  failed.