Soldiers stand next to a tank.
a man swims in a creek
Soldiers who stand cannot swim at the same time.
exists e1 x1 x2.(to(e1,x2) & n_tank(x2) & r_next(e1) & Actor(e1,x1) & v_stand(e1) & n_soldier(x1))
exists e1 x1 x2.(in(e1,x2) & n_creek(x2) & Actor(e1,x1) & v_swim(e1) & n_man(x1))