A person is rock climbing.
A person is practicing climbing in a gym.
You cannot assume that a person rock climbing is practicing climbing in a gym, because there are many places to go rock climbing outside.
exists p1 x1.(exists x2 x3.((x1 = x2) & n_climb(x2) & of(x2,x3) & n_rock(x3)) & n_person(x1))
exists e1 p1 x1.(exists e2 x2.(in(e2,x2) & n_gym(x2) & Actor(e2,x1) & v_climb(e2)) & Topic(e1,p1) & Actor(e1,x1) & v_practice(e1) & n_person(x1))