A rock climber practices on a rock climbing wall.
A rock climber is practicing.
A rock climber who practices does just that.
exists e1 x1 x2 x3 x4 x5 x6.(a_topic(x1) & on(x1,x4) & Theme(e1,x6) & Actor(e1,x5) & v_climb(e1) & n_wall(x6) & (x4 = x5) & n_rock(x4) & n_practice(x1) & of(x1,x3) & n_climber(x3) & of(x1,x2) & n_rock(x2))
exists e1 x1 x2.(Actor(e1,x1) & v_practice(e1) & n_climber(x1) & of(x1,x2) & n_rock(x2))