Man in a boat on a lake, surrounded by mountains and forestry.
Man on a boat in a river, surrounded by flatland.
The man on a boat has to be either on a lake or on a river, it can't be both.
exists e1 x1 x2 x3 x4 x5 x6 x7.(a_topic(x1) & in(x1,x2) & on(x2,x3) & Actor(e1,x5) & n_forestry(x7) & n_mountain(x6) & subset_of(x7,x5) & subset_of(x6,x5) & Theme(e1,x4) & v_surround(e1) & (x3 = x4) & n_lake(x3) & n_boat(x2) & n_man(x1))
exists e1 x1 x2 x3 x4 x5.(a_topic(x1) & on(x1,x2) & in(x2,x3) & Actor(e1,x5) & n_flatland(x5) & Theme(e1,x4) & v_surround(e1) & (x3 = x4) & n_river(x3) & n_boat(x2) & n_man(x1))