A person is surfing in the sea or ocean.
A person is learning to surf.
A person is surfing in the sea or ocean doesn't imply he is learning to surf.
exists e1 x1 x2.((n_sea(x2) | n_ocean(x2)) & in(e1,x2) & Actor(e1,x1) & v_surf(e1) & n_person(x1))
exists e1 x1 x2.(to(e1,x2) & n_surf(x2) & Actor(e1,x1) & v_learn(e1) & n_person(x1))