MAYBE

'epo* (timeout of 60.0 seconds)'
--------------------------------
Answer:           MAYBE
Input Problem:    innermost runtime-complexity with respect to
  Rules:
    {  app(nil(), k) -> k
     , app(l, nil()) -> l
     , app(cons(x, l), k) -> cons(x, app(l, k))
     , sum(cons(x, nil())) -> cons(x, nil())
     , sum(cons(x, cons(y, l))) -> sum(cons(a(x, y, h()), l))
     , a(h(), h(), x) -> s(x)
     , a(x, s(y), h()) -> a(x, y, s(h()))
     , a(x, s(y), s(z)) -> a(x, y, a(x, s(y), z))
     , a(s(x), h(), z) -> a(x, z, z)}

Proof Output:    
  The input cannot be shown compatible