A person is riding in a boat on a lake.
A person is in a boat on the lake.
If a person is in a boat, that means he/she is riding in a boat.
exists e1 x1 x2 x3.(in(e1,x2) & on(x2,x3) & n_lake(x3) & n_boat(x2) & Actor(e1,x1) & v_ride(e1) & n_person(x1))
exists p1 x1 x3.(n_lake(x3) & exists x2.(in(x1,x2) & on(x2,x3) & n_boat(x2)) & n_person(x1))