Two people working in mud.
Some people and some mud.
Some implies two or more.
exists e1 x1 x2 x3.(a_topic(x1) & in(e1,x3) & n_mud(x3) & Actor(e1,x2) & v_work(e1) & (x1 = x2) & n_people(x1) & card_eq_2(x1))
exists s1 x1 x2.(a_topic(s1) & subset_of(x2,s1) & n_mud(x2) & subset_of(x1,s1) & n_people(x1))