A girl is riding a white horse surrounded by green trees.
A girl walking while leading a horse.
She can't ride a white horse and walk while leading a horse at the same time.
exists e2 e1 s1 s2 x1 x2 x3 x4.(Theme(e2,x2) & Actor(e2,x1) & v_ride(e2) & Actor(e1,x4) & n_tree(x4) & a_green(s2) & Theme(s2,x4) & Theme(e1,x3) & v_surround(e1) & (x2 = x3) & n_horse(x2) & a_white(s1) & Theme(s1,x2) & n_girl(x1))
(x)