A lot of people are attending an aviation exposition.
People are at an aviation exposition.
attending and at are the same thing
exists e1 x1 x2 x3 x4.(Theme(e1,x3) & Actor(e1,x1) & v_attend(e1) & n_exposition(x3) & of(x3,x4) & n_aviation(x4) & of(x1,x2) & n_people(x2) & n_lot(x1))
exists p1 x1.(exists x2 x3.(at(x1,x2) & n_exposition(x2) & of(x2,x3) & n_aviation(x3)) & n_people(x1))