A rock climber ascends.
A man is climbing rocks.
A rock climber can practice or use their skills in many places not just on rocks.
exists e1 x1 x2.(Actor(e1,x1) & v_ascend(e1) & n_climber(x1) & of(x1,x2) & n_rock(x2))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_climb(e1) & n_rock(x2) & n_man(x1))