Students are sitting lined up on stair steps while they wait and check their electronic devices.
Students sit in line and wait for class while looking for updates on their phones.
Just because the students are sitting lined up on stair steps while they wait and check their electronic devices does not mean the electronic devices are their phones.
exists e1 p1 s2 x1 x4.(exists e2 p2 s1 x2 x3.(exists e4 e3.(Theme(e4,x4) & Actor(e4,x1) & v_check(e4) & Actor(e3,x1) & v_wait(e3)) & while(e2,p2) & on(e2,x2) & n_step(x2) & of(x2,x3) & n_stair(x3) & a_up(s1) & Manner(e2,s1) & Theme(e2,x1) & v_line(e2)) & n_device(x4) & a_electronic(s2) & Theme(s2,x4) & of(x4,x1) & n_thing(x1) & n_thing(x1) & Topic(e1,p1) & Actor(e1,x1) & v_sit(e1) & n_student(x1))
exists e2 e1 x1 x2 x3 x4 x5 x6 x7.(while(e1,e2) & for(e2,x6) & on(x6,x7) & n_phone(x7) & of(x7,x1) & n_thing(x1) & n_update(x6) & Actor(e2,x1) & v_look(e2) & for(e1,x5) & n_class(x5) & in(e1,x2) & n_wait(x4) & n_line(x3) & subset_of(x4,x2) & subset_of(x3,x2) & Actor(e1,x1) & v_sit(e1) & n_student(x1))