A female and a male each sit on the sofa with a child.
The child belongs to the female and male.
A child sitting on a sofa with a female and a male does not imply that the child belongs to the female and male.
exists e1 x1 x2 x3 x4.(n_sofa(x3) & with(e1,x4) & n_child(x4) & on(e1,x3) & Actor(e1,x1) & v_sit(e1) & all x6 x5.(((x5 = x6) & n_male(x6)) -> subset_of(x5,x1)) & subset_of(x2,x1) & n_female(x2))
exists e1 x1 x2 x3 x4.(n_male(x4) & n_female(x3) & subset_of(x4,x2) & subset_of(x3,x2) & n_child(x1) & to(e1,x2) & Actor(e1,x1) & v_belong(e1))