A young lady talking on her cellphone while sitting on steps.
The young lady talks to her boyfriend on the phone while she sits.
young lady talking on her cellphone does not imply she is taking to her boyfriend
exists e1 e2 s1 x1 x2 x3 x4.(a_topic(x1) & while(e1,e2) & on(e2,x4) & n_step(x4) & Actor(e2,x2) & v_sit(e2) & on(e1,x3) & n_cellphone(x3) & of(x3,x1) & n_female(x1) & Actor(e1,x2) & v_talk(e1) & (x1 = x2) & n_lady(x1) & a_young(s1) & Theme(s1,x1))
exists p1 p2 p3 s1 x1 x2 x3 x4 x5.(n_female(x3) & n_female(x3) & to(x1,x4) & on(x4,x5) & n_phone(x5) & n_boyfriend(x4) & of(x4,x3) & n_talk(x1) & of(x1,x2) & n_lady(x2) & a_young(s1) & Theme(s1,x1) & Time(p1,x1) & exists x6.n_event(x6) & exists e1.(Actor(e1,x3) & v_sit(e1)) & while(p2,p3))