A climber wearing a white helmet is perched on the side of a rock face.
A person in a white helmet is rock climbing.
a climber is a person. if they are perched on the side of a rock face, it follows that they are rock climbing.
exists e2 e1 s1 x1 x2 x3 x4 x5 x6.(n_side(x4) & on(e2,x4) & of(x4,x5) & n_face(x5) & of(x5,x6) & n_rock(x6) & Theme(e2,x1) & v_perch(e2) & Theme(e1,x3) & Actor(e1,x2) & v_wear(e1) & n_helmet(x3) & a_white(s1) & Theme(s1,x3) & (x1 = x2) & n_climber(x1))
exists p1 s1 x1 x2.(exists x3 x4.((x1 = x3) & n_climb(x3) & of(x3,x4) & n_rock(x4)) & in(x1,x2) & n_helmet(x2) & a_white(s1) & Theme(s1,x2) & n_person(x1))