The dressed up young people are sitting in chairs while they wait.
A dressed up young couple standing in chairs.
They can't be sitting in chairs and standing in chairs at the same time.
exists e1 e2 p1 s1 x1 x2.(n_thing(x1) & n_people(x1) & a_young(s1) & Theme(s1,x1) & r_up(x1) & Theme(e1,x1) & v_dress(e1) & exists e3.(Actor(e3,x1) & v_wait(e3)) & while(e2,p1) & in(e2,x2) & n_chair(x2) & Actor(e2,x1) & v_sit(e2))
exists e1 s1 s2 x1 x2 x3.(a_topic(x1) & in(x1,x3) & n_chair(x3) & n_standing(x1) & of(x1,x2) & n_couple(x2) & a_young(s2) & Theme(s2,x1) & a_up(s1) & Theme(s1,x1) & Theme(e1,x1) & v_dress(e1))