People in a gymnasium dancing in a contest.
People in a library studying.
Ones can be either in gymnasium or in a library. Once can be either dancing or studying.
exists x1 x2 x3 x4.(a_topic(x1) & in(x1,x2) & in(x2,x4) & n_contest(x4) & n_dancing(x2) & of(x2,x3) & n_gymnasium(x3) & n_people(x1))
exists e1 x1 x2 x3.(a_topic(x1) & in(x1,x2) & Actor(e1,x3) & v_study(e1) & (x2 = x3) & n_library(x2) & n_people(x1))