The girls were in the crowd.
The boys stood in the crowd.
Either there were boys or girls who stood in the crowd.
exists p1 x1 x2.(n_crowd(x2) & n_girl(x1) & in(x1,x2))
exists e1 x1 x2.(n_crowd(x2) & n_boy(x1) & in(e1,x2) & Actor(e1,x1) & v_stand(e1))