two people wearing masks, one green one purple.
Nobody is wearing masks.
Nobody is different than two people.
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_wear(e1) & rel(x3,x4) & n_purple(x4) & card_eq_1(x4) & card_eq_1(x4) & a_green(s1) & Theme(s1,x4) & n_mask(x3) & (x1 = x2) & n_people(x1) & card_eq_2(x1))
-exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_wear(e1) & n_mask(x2) & n_person(x1))