A rollerskater does tricks on a half pipe.
A rollerskater does a trick at a popular skate park.
Half pipes are not necessarily present at a skate park, and a skate park is not necessarily popular.
exists e1 x1 x2 x3 x4.(on(e1,x3) & n_pipe(x3) & of(x3,x4) & n_half(x4) & Theme(e1,x2) & Actor(e1,x1) & v_do(e1) & n_trick(x2) & n_rollerskater(x1))
exists e1 s1 x1 x2 x3 x4.(at(e1,x3) & n_park(x3) & of(x3,x4) & n_skate(x4) & a_popular(s1) & Theme(s1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_do(e1) & n_trick(x2) & n_rollerskater(x1))