The German shepherd leaps off the stairs.
A dog chases his ball down the stairs.
There is no mention of the German shepherd chasing a ball down the stairs.
exists e1 s1 s2 x1 x2.(n_stair(x2) & n_shepherd(x1) & a_german(s1) & Theme(s1,x1) & a_off(s2) & Manner(e1,s2) & Theme(e1,x2) & Actor(e1,x1) & v_leap(e1))
exists e1 x1 x2 x3.(n_stair(x3) & Theme(e1,x2) & Actor(e1,x1) & v_chase(e1) & down(x2,x3) & n_ball(x2) & of(x2,x1) & n_male(x1) & n_dog(x1))