A group of people walking between two buildings.
A group of students are sitting in class.
The group of people are walking, so they cannot be sitting.
exists e1 x1 x2 x3 x4.(a_topic(x1) & of(x1,x2) & between(e1,x4) & n_building(x4) & card_eq_2(x4) & Actor(e1,x3) & v_walk(e1) & (x2 = x3) & n_people(x2) & n_group(x1))
exists e1 x1 x2 x3.(in(e1,x3) & n_class(x3) & Actor(e1,x1) & v_sit(e1) & of(x1,x2) & n_student(x2) & n_group(x1))