People are taking pictures.
The people were talking on their smartphones.
The people cannot be taking pictures and talking on the smartphones simultaneously
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_take(e1) & n_picture(x2) & n_people(x1))
exists e1 x1 x2.(n_smartphone(x2) & of(x2,x1) & n_thing(x1) & n_people(x1) & on(e1,x2) & Actor(e1,x1) & v_talk(e1))