A diverse group of younger looking people seem to be waiting for a lecture to start.
The people are at school.
Just because people are waiting for a lecture doesn't mean that they are at school.
exists e2 e1 p1 s1 s2 x1 x2.(Topic(e2,p1) & Actor(e2,x1) & v_seem(e2) & exists e3 p2 x3.(for(e3,x3) & Topic(x3,p2) & exists e4.(Actor(e4,x3) & v_start(e4)) & n_lecture(x3) & Actor(e3,x1) & v_wait(e3)) & of(x1,x2) & n_people(x2) & Actor(e1,x2) & v_look(e1) & r_more(s2) & a_younger(s2) & Theme(s2,x2) & n_group(x1) & a_diverse(s1) & Theme(s1,x1))
exists p1 x1.(n_people(x1) & exists x2.(at(x1,x2) & n_school(x2)))