A class full of students.
A class of students waits to hear a science lecture.
Students are waiting to hear a science lecture.
exists s1 x1 x2 x3.(a_topic(x1) & of(s1,x3) & n_student(x3) & Theme(s1,x2) & a_full(s1) & (x1 = x2) & n_class(x1))
exists p1 x1 x2 x3.(a_topic(x1) & of(x1,x2) & Topic(x2,p1) & exists e1 x4 x5.(Theme(e1,x4) & Actor(e1,x2) & v_hear(e1) & n_lecture(x4) & of(x4,x5) & n_science(x5)) & Time(x2,x3) & n_wait(x3) & n_student(x2) & n_class(x1))