two people repel down into a hole.
The spelunkers are riding mountain bikes.
They would not be able to repel down into a hole and ride mountain bikes at the same time.
exists e1 s1 x1 x2.(into(e1,x2) & n_hole(x2) & a_down(s1) & Manner(e1,s1) & Actor(e1,x1) & v_repel(e1) & n_people(x1) & card_eq_2(x1))
exists e1 x1 x2 x3.(n_spelunker(x1) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_bike(x2) & of(x2,x3) & n_mountain(x3))