Two children walking up a hill away from ducks on a lake.
Two children are riding the ducks.
you cannot be walking up a hill and riding the ducks at the same time
exists e1 s1 x1 x2 x3 x4 x5.(a_topic(x1) & on(e1,x5) & n_lake(x5) & from(e1,x4) & n_duck(x4) & r_away(e1) & a_up(s1) & Manner(e1,s1) & Theme(e1,x3) & Actor(e1,x2) & v_walk(e1) & n_hill(x3) & (x1 = x2) & n_child(x1) & card_eq_2(x1))
exists e1 x1 x2.(n_duck(x2) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_child(x1) & card_eq_2(x1))