Two people in white tops and black aprons.
The people are cooking.
People in white tops and black aprons are not necessarily cooking.
exists s1 s2 x1 x2 x3 x4.(a_topic(x1) & in(x1,x2) & subset_of(x4,x2) & n_apron(x4) & a_black(s2) & Theme(s2,x4) & subset_of(x3,x2) & n_top(x3) & a_white(s1) & Theme(s1,x3) & n_people(x1) & card_eq_2(x1))
exists e1 x1.(n_people(x1) & Actor(e1,x1) & v_cook(e1))