A man is skating on a vert ramp
The man is skating on the street course.
Ramp and street are different.
exists e1 x1 x2 x3.(on(e1,x2) & n_ramp(x2) & of(x2,x3) & n_vert(x3) & Actor(e1,x1) & v_skate(e1) & n_man(x1))
exists e1 x1 x2 x3.(n_course(x2) & of(x2,x3) & n_street(x3) & n_man(x1) & on(e1,x2) & Actor(e1,x1) & v_skate(e1))