A group of people riding a roller coaster upside down.
A group of people rode a roller coaster but it stalled.
A group of people riding a roller coaster upside down and others rode a roller coaster but it stalled.
exists e1 s1 x1 x2 x3 x4 x5.(a_topic(x1) & of(x1,x2) & r_upside(e1) & a_down(s1) & Manner(e1,s1) & Theme(e1,x4) & Actor(e1,x3) & v_ride(e1) & n_coaster(x4) & of(x4,x5) & n_roller(x5) & (x2 = x3) & n_people(x2) & n_group(x1))
exists e2 e1 x1 x2 x3 x4.(Actor(e2,x1) & v_stall(e2) & n_thing(x1) & Theme(e1,x3) & Actor(e1,x1) & v_ride(e1) & n_coaster(x3) & of(x3,x4) & n_roller(x4) & of(x1,x2) & n_people(x2) & n_group(x1))