A teenager performing a trick on a stairway in public.
A teenager walks up the stairs.
The teenager cannot be performing a trick when he walks up the stairs
exists e1 x1 x2 x3 x4 x5.(a_topic(x1) & in(e1,x5) & n_public(x5) & on(e1,x4) & n_stairway(x4) & Theme(e1,x3) & Actor(e1,x2) & v_perform(e1) & n_trick(x3) & (x1 = x2) & n_teenager(x1))
exists e1 s1 x1 x2.(n_stair(x2) & a_up(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_walk(e1) & n_teenager(x1))