A person is rock climbing.
A person is engaged in a physical activity
Rock climbing  is a physical activity.
exists p1 x1.(exists x2 x3.((x1 = x2) & n_climb(x2) & of(x2,x3) & n_rock(x3)) & n_person(x1))
exists e1 s1 x1 x2.(in(e1,x2) & n_activity(x2) & a_physical(s1) & Theme(s1,x2) & Theme(e1,x1) & v_engage(e1) & n_person(x1))