three children playy together.
Three children are good friends.
Just because children are playing together doesn't necessarily mean that they are good friends.
exists x1.(a_topic(x1) & n_playy(x1) & r_together(x1) & n_child(x1) & card_eq_3(x1))
exists p1 x1.(exists s1 x2.((x1 = x2) & n_friend(x2) & a_good(s1) & Theme(s1,x2)) & n_child(x1) & card_eq_3(x1))