Two chinese people are standing by a chalkboard.
A professor about to teach his student something on a chalkboard.
Two people standing by a chalkboard does not make them a professor about to teach his student. They could be two students or two professors and no one could be teaching anyone anything.
exists e1 s1 x1 x2.(by(e1,x2) & n_chalkboard(x2) & Actor(e1,x1) & v_stand(e1) & n_people(x1) & a_chinese(s1) & Theme(s1,x1) & card_eq_2(x1))
exists p1 s1 x1 x2 x3.(a_topic(x1) & Topic(s1,p1) & Actor(s1,x2) & a_about(s1) & exists e1 s2 x4.(on(e1,x4) & n_chalkboard(x4) & a_something(s2) & Manner(e1,s2) & Theme(e1,x3) & Actor(e1,x2) & v_teach(e1)) & n_student(x3) & of(x3,x1) & n_male(x1) & (x1 = x2) & n_professor(x1))