Several people are fishing in an extensive body of water beside a large bridge.
Some of the people have gone fishing there before.
The first sentence does not imply that some of the people have been fishing there before.
exists e1 s1 s2 s3 x1 x2 x3 x4.(in(e1,x2) & beside(x2,x4) & n_bridge(x4) & a_large(s3) & Theme(s3,x4) & of(x2,x3) & n_water(x3) & n_body(x2) & a_extensive(s2) & Theme(s2,x2) & Actor(e1,x1) & v_fish(e1) & n_people(x1) & a_several(s1) & Theme(s1,x1))
exists e1 s1 s2 x1 x2 x3.(n_people(x2) & a_before(s2) & Manner(e1,s2) & a_there(s1) & Manner(e1,s1) & Theme(e1,x3) & Actor(e1,x1) & v_go(e1) & n_fishing(x3) & of(x1,x2) & n_thing(x1))