A rollerblade athlete takes a big jump while performing a trick.
A rollerblader gives a demo for children.
A rollerblader is not necessarily an athlete. Just because the athlete takes a big jump does not mean he is giving a demo for children.
exists e2 e1 s1 x1 x2 x3 x4.(while(e1,e2) & Theme(e2,x4) & Actor(e2,x1) & v_perform(e2) & n_trick(x4) & Theme(e1,x3) & Actor(e1,x1) & v_take(e1) & n_jump(x3) & a_big(s1) & Theme(s1,x3) & n_athlete(x1) & of(x1,x2) & n_rollerblade(x2))
exists e1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_give(e1) & for(x2,x3) & n_child(x3) & n_demo(x2) & n_rollerblader(x1))