A person in brown shirt is doing rock climbing.
Someone is climbing the stairs.
A person can't be rock climbing on stairs.
exists e1 s1 x1 x2 x3 x4.(Theme(e1,x3) & Actor(e1,x1) & v_do(e1) & n_climb(x3) & of(x3,x4) & n_rock(x4) & in(x1,x2) & n_shirt(x2) & a_brown(s1) & Theme(s1,x2) & n_person(x1))
exists e1 x1 x2.(n_stair(x2) & Theme(e1,x2) & Actor(e1,x1) & v_climb(e1) & n_person(x1))