People are seated outdoors to see someone on stage.
people at concert
The fact that people are seated outdoors to see someone on stage doesn't imply that they are at a concert.
exists e1 p1 x1 x2 x3.(Topic(e1,p1) & exists e2 x4 x5.(on(e2,x5) & n_stage(x5) & Theme(e2,x4) & Actor(e2,x1) & v_see(e2) & n_person(x4)) & Recipient(e1,x3) & Theme(e1,x2) & v_seat(e1) & n_outdoors(x3) & n_people(x2) & n_people(x1))
exists x1 x2.(a_topic(x1) & at(x1,x2) & n_concert(x2) & n_people(x1))