Three young boys enjoying nature.
the boys are very upset and not enjoying nature
In the first sentence, they are enjoying nature, but the 2nd sentence they are not enjoying it. These actions are contradictory because you can't enjoy something and not enjoy it at the same time.
exists e1 s1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_enjoy(e1) & n_nature(x3) & (x1 = x2) & n_boy(x1) & a_young(s1) & Theme(s1,x1) & card_eq_3(x1))
exists s1 s2 x1 x2 x3.(n_boy(x1) & a_topic(s1) & -exists e1 x4.(subset_of(e1,s1) & Theme(e1,x4) & Actor(e1,x3) & v_enjoy(e1) & n_nature(x4)) & n_thing(x3) & subset_of(x1,s1) & r_very(s2) & Theme(s2,x2) & a_upset(s2) & (x1 = x2))