MAYBE

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

Proof:
 RT Transformation Processor:
  strict:
   c(c(x1)) -> a(b(x1))
   b(x1) -> a(a(x1))
   b(b(b(x1))) -> a(c(b(x1)))
   a(c(a(x1))) -> a(c(c(x1)))
  weak:
   
  Matrix Interpretation Processor:
   dimension: 1
   interpretation:
    [a](x0) = x0 + 1,
    
    [b](x0) = x0 + 3,
    
    [c](x0) = x0 + 13
   orientation:
    c(c(x1)) = x1 + 26 >= x1 + 4 = a(b(x1))
    
    b(x1) = x1 + 3 >= x1 + 2 = a(a(x1))
    
    b(b(b(x1))) = x1 + 9 >= x1 + 17 = a(c(b(x1)))
    
    a(c(a(x1))) = x1 + 15 >= x1 + 27 = a(c(c(x1)))
   problem:
    strict:
     b(b(b(x1))) -> a(c(b(x1)))
     a(c(a(x1))) -> a(c(c(x1)))
    weak:
     c(c(x1)) -> a(b(x1))
     b(x1) -> a(a(x1))
   Matrix Interpretation Processor:
    dimension: 1
    interpretation:
     [a](x0) = x0 + 4,
     
     [b](x0) = x0 + 8,
     
     [c](x0) = x0 + 6
    orientation:
     b(b(b(x1))) = x1 + 24 >= x1 + 18 = a(c(b(x1)))
     
     a(c(a(x1))) = x1 + 14 >= x1 + 16 = a(c(c(x1)))
     
     c(c(x1)) = x1 + 12 >= x1 + 12 = a(b(x1))
     
     b(x1) = x1 + 8 >= x1 + 8 = a(a(x1))
    problem:
     strict:
      a(c(a(x1))) -> a(c(c(x1)))
     weak:
      b(b(b(x1))) -> a(c(b(x1)))
      c(c(x1)) -> a(b(x1))
      b(x1) -> a(a(x1))
    Open