A man on rollerblades grinds a wall.
A man is skating.
Skating is done with rollerblades.
exists e1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_grind(e1) & n_wall(x3) & on(x1,x2) & n_rollerblade(x2) & n_man(x1))
exists e1 x1.(Actor(e1,x1) & v_skate(e1) & n_man(x1))