A priest delivering mass in a church.
A priest is preaching
If there is a priest delivering mass than a priest is preaching.
exists e1 x1 x2 x3 x4.(a_topic(x1) & in(e1,x4) & n_church(x4) & Theme(e1,x3) & Actor(e1,x2) & v_deliver(e1) & n_mass(x3) & (x1 = x2) & n_priest(x1))
exists e1 x1.(Actor(e1,x1) & v_preach(e1) & n_priest(x1))