A boy is rock climbing.
A boy is on a rock climbing simulator.
The boy does not need to be in a rock climbing simulator to climb rocks.
exists p1 x1.(exists x2 x3.((x1 = x2) & n_climb(x2) & of(x2,x3) & n_rock(x3)) & n_boy(x1))
exists p1 x1.(exists e1 x2 x3.(on(x1,x2) & n_simulator(x2) & Actor(e1,x2) & v_climb(e1) & of(x2,x3) & n_rock(x3)) & n_boy(x1))