A crowd of people is gathered in front of a bank.
There is nobody in front of the bank.
There is either a crowd of people or nobody.
exists e1 x1 x2 x3 x4.(in(e1,x3) & of(x3,x4) & n_bank(x4) & n_front(x3) & Theme(e1,x1) & v_gather(e1) & of(x1,x2) & n_people(x2) & n_crowd(x1))
exists p1 x1 x4.(n_bank(x4) & -exists x2 x3.((x1 = x2) & in(x2,x3) & of(x3,x4) & n_front(x3) & n_person(x2)))