A person standing on a frozen lake.
a person is swimming in a lake
A person cant be swimming in a frozen lake.
exists e1 s1 x1 x2 x3.(a_topic(x1) & on(e1,x3) & n_lake(x3) & a_frozen(s1) & Theme(s1,x3) & Actor(e1,x2) & v_stand(e1) & (x1 = x2) & n_person(x1))
exists e1 x1 x2.(in(e1,x2) & n_lake(x2) & Actor(e1,x1) & v_swim(e1) & n_person(x1))