Two fisherman walking to work by the pier.
Two fisherman are walking and trip then fall.
Walking doesn't always result in a trip then fall.
exists p1 x1 x2 x3.(n_pier(x3) & a_topic(x1) & Topic(x1,p1) & exists e1.(by(e1,x3) & Actor(e1,x1) & v_work(e1)) & n_walking(x1) & of(x1,x2) & n_fisherman(x2) & card_eq_2(x1))
exists e2 e1 s1 x1 x2 x3.(Actor(e2,x1) & v_fall(e2) & a_then(s1) & Manner(e1,s1) & Theme(e1,x3) & Actor(e1,x2) & v_walk(e1) & n_trip(x3) & (x1 = x2) & n_fisherman(x1) & card_eq_2(x1))