A man sitting in a boat is floating near a cave.
A man is standing up in a boat.
sitting while standing is an impossibility.
exists e2 e1 x1 x2 x3 x4.(near(e2,x4) & n_cave(x4) & Actor(e2,x1) & v_float(e2) & in(e1,x3) & n_boat(x3) & Actor(e1,x2) & v_sit(e1) & (x1 = x2) & n_man(x1))
exists e1 s1 x1 x2.(in(e1,x2) & n_boat(x2) & a_up(s1) & Manner(e1,s1) & Actor(e1,x1) & v_stand(e1) & n_man(x1))