The man is skateboarding on a large brick staircase.
The man is skateboarding at a school.
Not all large brick staircases are at a school.
exists e1 s1 x1 x2 x3.(n_man(x1) & on(e1,x2) & n_staircase(x2) & of(x2,x3) & n_brick(x3) & a_large(s1) & Theme(s1,x2) & Actor(e1,x1) & v_skateboard(e1))
exists e1 x1 x2.(n_man(x1) & at(e1,x2) & n_school(x2) & Actor(e1,x1) & v_skateboard(e1))