A biker is practicing a trick while his friend watch him as his audience.
children walking in the wall.
A biker practicing a trick cannot be the one walking.
exists e1 s1 x1 x2 x3 x4 x5.(as(e1,x5) & n_audience(x5) & of(x5,x1) & n_male(x1) & n_male(x1) & a_he(s1) & Manner(e1,s1) & while(e1,x3) & n_watch(x3) & of(x3,x4) & n_friend(x4) & of(x3,x1) & Theme(e1,x2) & Actor(e1,x1) & v_practice(e1) & n_trick(x2) & n_biker(x1))
exists e1 x1 x2 x3.(n_wall(x3) & a_topic(x1) & in(e1,x3) & Actor(e1,x2) & v_walk(e1) & (x1 = x2) & n_child(x1))