A skateboard rolling down a ramp.
A dog is pushing the skateboard up the ramp.
The skateboard can't be doing up and down at the same time.
exists e1 s1 x1 x2 x3.(a_topic(x1) & a_down(s1) & Manner(e1,s1) & Theme(e1,x3) & Actor(e1,x2) & v_roll(e1) & n_ramp(x3) & (x1 = x2) & n_skateboard(x1))
exists e1 x1 x2 x3.(n_ramp(x3) & n_skateboard(x2) & up(e1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_push(e1) & n_dog(x1))