Four students are sitting on the floor by a model volcano.
Four students are sitting together.
Four students are sitting shows that the  students are sitting together.
exists e1 x1 x2 x3 x4.(n_floor(x2) & by(e1,x3) & n_volcano(x3) & of(x3,x4) & n_model(x4) & on(e1,x2) & Actor(e1,x1) & v_sit(e1) & n_student(x1) & card_eq_4(x1))
exists e1 p1 x1.(exists s1.(Theme(s1,x1) & a_together(s1)) & Topic(e1,p1) & Actor(e1,x1) & v_sit(e1) & n_student(x1) & card_eq_4(x1))