A boy with glasses on is sitting in a chair at the dentist.
a boy is in dentist place
He is probably at th dentist's office, not the dentist's place.
exists e1 s1 x1 x2 x3 x4 x5.(n_dentist(x5) & at(e1,x5) & in(e1,x4) & n_chair(x4) & Actor(e1,x1) & v_sit(e1) & with(x1,x2) & Theme(s1,x3) & a_on(s1) & (x2 = x3) & n_glass(x2) & n_boy(x1))
exists p1 x1.(exists x2 x3.(in(x1,x2) & n_place(x2) & of(x2,x3) & n_dentist(x3)) & n_boy(x1))