A woman and her son walk down a long, leaf-strewn path, while two people ride their horses in the opposite direction.
The horse riders passed the woman and her son.
People who ride horses are horse riders, and if they ride in the opposite direction from people who walk, the have passed the people.
exists e1 p1 s1 s2 x1 x2 x3 x4 x5 x6 x8 x9.(n_direction(x9) & a_opposite(s2) & Theme(s2,x9) & exists e2 x7.(Theme(e2,x8) & Actor(e2,x7) & v_ride(e2) & in(x8,x9) & n_people(x7) & card_eq_2(x7)) & n_horse(x8) & of(x8,x2) & n_thing(x2) & while(e1,p1) & down(e1,x4) & n_path(x6) & a_leaf-strewn(s1) & Theme(s1,x6) & n_long(x5) & subset_of(x6,x4) & subset_of(x5,x4) & Actor(e1,x1) & v_walk(e1) & subset_of(x3,x1) & n_son(x3) & of(x3,x2) & n_female(x2) & subset_of(x2,x1) & n_woman(x2))
exists e1 x1 x2 x3 x4 x5.(n_son(x5) & of(x5,x4) & n_female(x4) & n_woman(x4) & n_rider(x1) & of(x1,x2) & n_horse(x2) & Theme(e1,x3) & Actor(e1,x1) & v_pass(e1) & subset_of(x5,x3) & subset_of(x4,x3))