YES(?,O(n^1))

We are left with following problem, upon which TcT provides the
certificate YES(?,O(n^1)).

Strict Trs:
  { +(0(), y) -> y
  , +(s(x), y) -> s(+(x, y))
  , -(x, 0()) -> x
  , -(0(), y) -> 0()
  , -(s(x), s(y)) -> -(x, y) }
Obligation:
  innermost runtime complexity
Answer:
  YES(?,O(n^1))

The input was oriented with the instance of 'Small Polynomial Path
Order (1-bounded)' as induced by the safe mapping

 safe(+) = {2}, safe(0) = {}, safe(s) = {1}, safe(-) = {1}

and precedence

 empty .

Following symbols are considered recursive:

 {+, -}

The recursion depth is 1.

For your convenience, here are the satisfied ordering constraints:

          +(0(); y) > y           
                                  
       +(s(; x); y) > s(; +(x; y))
                                  
          -(0(); x) > x           
                                  
          -(y; 0()) > 0()         
                                  
  -(s(; y); s(; x)) > -(y; x)     
                                  

Hurray, we answered YES(?,O(n^1))