MAYBE

We are left with following problem, upon which TcT provides the
certificate MAYBE.

Strict Trs:
  { append(@l1, @l2) -> append#1(@l1, @l2)
  , append#1(::(@x, @xs), @l2) -> ::(@x, append(@xs, @l2))
  , append#1(nil(), @l2) -> @l2
  , subtrees(@t) -> subtrees#1(@t)
  , subtrees#1(leaf()) -> nil()
  , subtrees#1(node(@x, @t1, @t2)) ->
    subtrees#2(subtrees(@t1), @t1, @t2, @x)
  , subtrees#2(@l1, @t1, @t2, @x) ->
    subtrees#3(subtrees(@t2), @l1, @t1, @t2, @x)
  , subtrees#3(@l2, @l1, @t1, @t2, @x) ->
    ::(node(@x, @t1, @t2), append(@l1, @l2)) }
Obligation:
  innermost runtime complexity
Answer:
  MAYBE

None of the processors succeeded.

Details of failed attempt(s):
-----------------------------
1) 'Fastest' failed due to the following reason:
   
   None of the processors succeeded.
   
   Details of failed attempt(s):
   -----------------------------
   1) 'matrix interpretation of dimension 4' failed due to the
      following reason:
      
      The input cannot be shown compatible
   
   2) 'matrix interpretation of dimension 3' failed due to the
      following reason:
      
      The input cannot be shown compatible
   
   3) 'matrix interpretation of dimension 3' failed due to the
      following reason:
      
      The input cannot be shown compatible
   
   4) 'matrix interpretation of dimension 2' failed due to the
      following reason:
      
      The input cannot be shown compatible
   
   5) 'matrix interpretation of dimension 2' failed due to the
      following reason:
      
      The input cannot be shown compatible
   
   6) 'matrix interpretation of dimension 1' failed due to the
      following reason:
      
      The input cannot be shown compatible
   

2) 'Fastest' failed due to the following reason:
   
   None of the processors succeeded.
   
   Details of failed attempt(s):
   -----------------------------
   1) 'custom shape polynomial interpretation' failed due to the
      following reason:
      
      The input cannot be shown compatible
   
   2) 'linear polynomial interpretation' failed due to the following
      reason:
      
      The input cannot be shown compatible
   
   3) 'custom shape polynomial interpretation' failed due to the
      following reason:
      
      The input cannot be shown compatible
   


Arrrr..