Someone is in a speed boat on the water.
A person is in a speed boat and stranded in the middle of the lake.
Not all speed boats are stranded in the middle of the lake.
exists p1 x1 x4.(n_water(x4) & exists x2 x3.(in(x1,x2) & on(x2,x4) & n_boat(x2) & of(x2,x3) & n_speed(x3)) & n_person(x1))
exists e1 e3 e2 x1 x2 x3 x4 x5 x6.(n_lake(x6) & n_middle(x5) & for(e2,e3) & in(e3,x5) & of(x5,x6) & Theme(e3,x4) & v_strand(e3) & Actor(e2,x4) & v_be(e2) & n_person(x4) & in(e1,x2) & n_boat(x2) & of(x2,x3) & n_speed(x3) & Actor(e1,x1) & v_be(e1) & n_person(x1))