Business people talk after making a presentation.
Businessmen are talking.
Not all business people are businessmen.
exists e1 e2 x1 x2 x3.(after(e1,e2) & Theme(e2,x3) & Actor(e2,x1) & v_make(e2) & n_presentation(x3) & Actor(e1,x1) & v_talk(e1) & n_people(x1) & of(x1,x2) & n_business(x2))
exists e1 x1.(Actor(e1,x1) & v_talk(e1) & n_businessman(x1))