Three skateboarders are in a park.
people skateboard
Three skateboarders implies people.
exists p1 x1.(exists x2.(in(x1,x2) & n_park(x2)) & n_skateboarder(x1) & card_eq_3(x1))
exists e1 x1.(Actor(e1,x1) & v_skateboard(e1) & n_people(x1))