Two people are at a park.
Two people are at an ice rink.
Two people cannot be at a park and at an ice rink at the same time.
exists p1 x1.(exists x2.(at(x1,x2) & n_park(x2)) & n_people(x1) & card_eq_2(x1))
exists p1 x1.(exists x2 x3.(at(x1,x2) & n_rink(x2) & of(x2,x3) & n_ice(x3)) & n_people(x1) & card_eq_2(x1))