Two women talk and laugh while people walk by.
Two men eating Mexican food.
Subject could be either women or men.
(-x)
exists e1 s1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_eat(e1) & n_food(x3) & a_mexican(s1) & Theme(s1,x3) & (x1 = x2) & n_man(x1) & card_eq_2(x1))