A young male child is playing on a climbing wall.
A child is climbing.
"Playing on a climbing wall" is a rephrasing of "climbing."
exists e1 e2 s1 s2 x1 x2.(on(e1,x2) & n_wall(x2) & Actor(e2,x2) & v_climb(e2) & Actor(e1,x1) & v_play(e1) & n_child(x1) & a_male(s2) & Theme(s2,x1) & a_young(s1) & Theme(s1,x1))
exists e1 x1.(Actor(e1,x1) & v_climb(e1) & n_child(x1))