A man wearing a life jacket uses a map while on a small boat.
The man uses celestial navigation as well as the map for navigation.
Using a map does not imply using celestial navigation.
exists e1 e2 s1 x1 x2 x3 x4 x5 x6.(on(e2,x6) & n_boat(x6) & a_small(s1) & Theme(s1,x6) & r_while(e2) & Theme(e2,x5) & Actor(e2,x1) & v_use(e2) & n_map(x5) & Theme(e1,x3) & Actor(e1,x2) & v_wear(e1) & n_jacket(x3) & of(x3,x4) & n_life(x4) & (x1 = x2) & n_man(x1))
exists e1 s1 x1 x2 x3 x4 x5.(n_map(x4) & n_man(x1) & Theme(e1,x2) & Actor(e1,x1) & v_use(e1) & subset_of(x4,x2) & for(x4,x5) & n_navigation(x5) & subset_of(x3,x2) & n_navigation(x3) & a_celestial(s1) & Theme(s1,x3))