Two women are sitting and talking.
Two women are sitting on a bench.
people can sit on any number of types of furniture and no context is given to imply that the type of furniture is a bench.
exists e1 e2 x1 x2.(Actor(e2,x2) & v_talk(e2) & n_woman(x2) & card_eq_2(x2) & Actor(e1,x1) & v_sit(e1) & n_woman(x1) & card_eq_2(x1))
exists e1 x1 x2.(on(e1,x2) & n_bench(x2) & Actor(e1,x1) & v_sit(e1) & n_woman(x1) & card_eq_2(x1))