A middle-aged man and women in a blue shirt look at the man's diploma.
two parents look at their son's diploma
Just because a middle-aged man and women in a blue shirt are looking at a man's diploma dose not mean that they are parents, or that the man whose diploma they are looking at is there son.
exists s1 s2 s3 x1 x2 x3 x4 x5.(a_topic(s1) & subset_of(x2,s1) & in(x2,x3) & at(x3,x5) & n_diploma(x5) & of(x5,x1) & n_man(x1) & n_man(x1) & n_look(x3) & of(x3,x4) & n_shirt(x4) & a_blue(s3) & Theme(s3,x3) & n_woman(x2) & subset_of(x1,s1) & a_middle-aged(s2) & Theme(s2,x1))
exists e1 x1 x2 x3.(at(e1,x3) & n_diploma(x3) & of(x3,x2) & n_son(x2) & of(x2,x1) & n_thing(x1) & Actor(e1,x1) & v_look(e1) & n_parent(x1) & card_eq_2(x1))