MAYBE
Input TRS:
      1: f(a(),f(a(),f(a(),f(x,b())))) -> f(f(a(),f(a(),f(a(),x))),b())
      2: f(f(f(a(),x),b()),b()) -> f(f(a(),f(f(x,b()),b())),b())
Number of strict rules: 2
Direct POLO(bPol) ... failed.
Uncurrying ... failed.
Dependency Pairs:
     #1: #f(f(f(a(),x),b()),b()) -> #f(f(a(),f(f(x,b()),b())),b())
     #2: #f(f(f(a(),x),b()),b()) -> #f(a(),f(f(x,b()),b()))
     #3: #f(f(f(a(),x),b()),b()) -> #f(f(x,b()),b())
     #4: #f(f(f(a(),x),b()),b()) -> #f(x,b())
     #5: #f(a(),f(a(),f(a(),f(x,b())))) -> #f(f(a(),f(a(),f(a(),x))),b())
     #6: #f(a(),f(a(),f(a(),f(x,b())))) -> #f(a(),f(a(),f(a(),x)))
     #7: #f(a(),f(a(),f(a(),f(x,b())))) -> #f(a(),f(a(),x))
     #8: #f(a(),f(a(),f(a(),f(x,b())))) -> #f(a(),x)
Number of SCCs: 1, DPs: 8
  SCC { #1..8 }
POLO(Sum)... succeeded.
      a 	w: 21239
      b 	w: 0
      f 	w: x1 + x2
      #f 	w: x1 + x2
    USABLE RULES: { 1 2 }
    Removed DPs: #3 #4 #7 #8
Number of SCCs: 1, DPs: 4
  SCC { #1 #2 #5 #6 }
POLO(Sum)... POLO(max)... QLPOS... POLO(mSum)... QWPOpS(mSum)... Mat2b... succeeded.
      a 	w: [1;5723]
      b 	w: [42258;0]
      f 	w: [0,0;0,1] * x1 + [0,1;0,1] * x2 + [36536;0]
      #f 	w: [0,0;0,1] * x1 + x2
    USABLE RULES: { 1 2 }
    Removed DPs: #2 #5
Number of SCCs: 2, DPs: 2
  SCC { #6 }
POLO(Sum)... POLO(max)... QLPOS... POLO(mSum)... QWPOpS(mSum)... Mat2b... failed.
Finding a loop...  failed.