YES

Problem:
 a(x1) -> x1
 a(a(b(x1))) -> b(a(b(a(x1))))
 b(b(x1)) -> c(a(x1))

Proof:
 String Reversal Processor:
  a(x1) -> x1
  b(a(a(x1))) -> a(b(a(b(x1))))
  b(b(x1)) -> a(c(x1))
  DP Processor:
   DPs:
    b#(a(a(x1))) -> b#(x1)
    b#(a(a(x1))) -> a#(b(x1))
    b#(a(a(x1))) -> b#(a(b(x1)))
    b#(a(a(x1))) -> a#(b(a(b(x1))))
    b#(b(x1)) -> a#(c(x1))
   TRS:
    a(x1) -> x1
    b(a(a(x1))) -> a(b(a(b(x1))))
    b(b(x1)) -> a(c(x1))
   TDG Processor:
    DPs:
     b#(a(a(x1))) -> b#(x1)
     b#(a(a(x1))) -> a#(b(x1))
     b#(a(a(x1))) -> b#(a(b(x1)))
     b#(a(a(x1))) -> a#(b(a(b(x1))))
     b#(b(x1)) -> a#(c(x1))
    TRS:
     a(x1) -> x1
     b(a(a(x1))) -> a(b(a(b(x1))))
     b(b(x1)) -> a(c(x1))
    graph:
     b#(a(a(x1))) -> b#(a(b(x1))) -> b#(b(x1)) -> a#(c(x1))
     b#(a(a(x1))) -> b#(a(b(x1))) -> b#(a(a(x1))) -> a#(b(a(b(x1))))
     b#(a(a(x1))) -> b#(a(b(x1))) -> b#(a(a(x1))) -> b#(a(b(x1)))
     b#(a(a(x1))) -> b#(a(b(x1))) -> b#(a(a(x1))) -> a#(b(x1))
     b#(a(a(x1))) -> b#(a(b(x1))) -> b#(a(a(x1))) -> b#(x1)
     b#(a(a(x1))) -> b#(x1) -> b#(b(x1)) -> a#(c(x1))
     b#(a(a(x1))) -> b#(x1) -> b#(a(a(x1))) -> a#(b(a(b(x1))))
     b#(a(a(x1))) -> b#(x1) -> b#(a(a(x1))) -> b#(a(b(x1)))
     b#(a(a(x1))) -> b#(x1) -> b#(a(a(x1))) -> a#(b(x1))
     b#(a(a(x1))) -> b#(x1) -> b#(a(a(x1))) -> b#(x1)
    SCC Processor:
     #sccs: 1
     #rules: 2
     #arcs: 10/25
     DPs:
      b#(a(a(x1))) -> b#(a(b(x1)))
      b#(a(a(x1))) -> b#(x1)
     TRS:
      a(x1) -> x1
      b(a(a(x1))) -> a(b(a(b(x1))))
      b(b(x1)) -> a(c(x1))
     Arctic Interpretation Processor:
      dimension: 2
      interpretation:
       [b#](x0) = [-& 0 ]x0 + [0],
       
                 [0 ]
       [c](x0) = [-&],
       
                 [0  -&]     [2]
       [b](x0) = [0  -&]x0 + [0],
       
                 [0 2]     [-&]
       [a](x0) = [2 2]x0 + [2 ]
      orientation:
       b#(a(a(x1))) = [4 4]x1 + [4] >= [2  -&]x1 + [4] = b#(a(b(x1)))
       
       b#(a(a(x1))) = [4 4]x1 + [4] >= [-& 0 ]x1 + [0] = b#(x1)
       
               [0 2]     [-&]           
       a(x1) = [2 2]x1 + [2 ] >= x1 = x1
       
                     [4 4]     [4]    [4  -&]     [4]                 
       b(a(a(x1))) = [4 4]x1 + [4] >= [4  -&]x1 + [4] = a(b(a(b(x1))))
       
                  [0  -&]     [2]    [0]           
       b(b(x1)) = [0  -&]x1 + [2] >= [2] = a(c(x1))
      problem:
       DPs:
        b#(a(a(x1))) -> b#(a(b(x1)))
       TRS:
        a(x1) -> x1
        b(a(a(x1))) -> a(b(a(b(x1))))
        b(b(x1)) -> a(c(x1))
      EDG Processor:
       DPs:
        b#(a(a(x1))) -> b#(a(b(x1)))
       TRS:
        a(x1) -> x1
        b(a(a(x1))) -> a(b(a(b(x1))))
        b(b(x1)) -> a(c(x1))
       graph:
        b#(a(a(x1))) -> b#(a(b(x1))) -> b#(a(a(x1))) -> b#(a(b(x1)))
       Arctic Interpretation Processor:
        dimension: 2
        interpretation:
         [b#](x0) = [-& 0 ]x0 + [0],
         
                   [0 ]
         [c](x0) = [-&],
         
                   [-& 1 ]     [0]
         [b](x0) = [-& 0 ]x0 + [0],
         
                   [0 2]     [1]
         [a](x0) = [0 0]x0 + [0]
        orientation:
         b#(a(a(x1))) = [0 2]x1 + [1] >= [-& 1 ]x1 + [0] = b#(a(b(x1)))
         
                 [0 2]     [1]           
         a(x1) = [0 0]x1 + [0] >= x1 = x1
         
                       [1 3]     [2]    [-& 3 ]     [2]                 
         b(a(a(x1))) = [0 2]x1 + [1] >= [-& 2 ]x1 + [1] = a(b(a(b(x1))))
         
                    [-& 1 ]     [1]    [1]           
         b(b(x1)) = [-& 0 ]x1 + [0] >= [0] = a(c(x1))
        problem:
         DPs:
          
         TRS:
          a(x1) -> x1
          b(a(a(x1))) -> a(b(a(b(x1))))
          b(b(x1)) -> a(c(x1))
        Qed