YES(?,ELEMENTARY)

We are left with following problem, upon which TcT provides the
certificate YES(?,ELEMENTARY).

Strict Trs:
  { rev(a()) -> a()
  , rev(b()) -> b()
  , rev(++(x, x)) -> rev(x)
  , rev(++(x, y)) -> ++(rev(y), rev(x)) }
Obligation:
  innermost runtime complexity
Answer:
  YES(?,ELEMENTARY)

The input was oriented with the instance of 'Lightweight Multiset
Path Order' as induced by the safe mapping

 safe(rev) = {}, safe(a) = {}, safe(b) = {}, safe(++) = {1, 2}

and precedence

 empty .

Following symbols are considered recursive:

 {rev}

The recursion depth is 1.

For your convenience, here are the satisfied ordering constraints:

          rev(a();) > a()                    
                                             
          rev(b();) > b()                    
                                             
  rev(++(; x,  x);) > rev(x;)                
                                             
  rev(++(; x,  y);) > ++(; rev(y;),  rev(x;))
                                             

Hurray, we answered YES(?,ELEMENTARY)