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

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

The problem is match-bounded by 1. The enriched problem is
compatible with the following automaton.
{ f_0(2) -> 1
, f_1(3) -> 1
, c_0(2, 2) -> 2
, c_1(2, 4) -> 3
, c_1(4, 2) -> 5
, s_0(2) -> 2
, s_1(2) -> 4
, s_1(4) -> 4
, g_0(2) -> 1
, g_1(5) -> 1 }

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