The man is skateboarding on a large brick staircase.
A person is being dangerous
Not everyone who skateboards is being dangerous.
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 s1 x1.(Theme(s1,x1) & a_dangerous(s1) & n_person(x1))