Many people are walking in a large public space, some are talking on cellphones.
Some people are on their phones.
Cellphones are a type of phones
exists e1 p1 s1 s2 x1 x2.(in(e1,x2) & exists e2 x3 x4.(on(e2,x4) & n_cellphone(x4) & Actor(e2,x3) & v_talk(e2) & n_thing(x3)) & that(x2,p1) & n_space(x2) & a_public(s2) & Theme(s2,x2) & a_large(s1) & Theme(s1,x2) & Actor(e1,x1) & v_walk(e1) & n_people(x1) & n_quantity(x1))
exists p1 x1 x2.(on(x1,x2) & n_phone(x2) & of(x2,x1) & n_thing(x1) & n_people(x1))