A class full of students.
A professor speaks with a single student.
There is either a class full of student or a single student.
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 e1 s1 x1 x2.(with(e1,x2) & n_student(x2) & a_single(s1) & Theme(s1,x2) & Actor(e1,x1) & v_speak(e1) & n_professor(x1))