premise: A boy stands in the middle of a crowd of teenagers.
hypothesis: A sad boy stands in the middle of a crowd of teenagers.
explanation_1: Not all boys are sad.
explanation_2: Not all boys standing in the middle of a crowd are sad.
explanation_3: We weren't told he's sad in the first sentence.
premise_logic: exists e1 x1 x2 x3 x4.(n_middle(x2) & in(e1,x2) & of(x2,x3) & of(x3,x4) & n_teenager(x4) & n_crowd(x3) & Actor(e1,x1) & v_stand(e1) & n_boy(x1))
hypothesis_logic: exists s1 x1 x2 x3 x4 x5.(n_middle(x3) & a_topic(x1) & in(x1,x3) & of(x3,x4) & of(x4,x5) & n_teenager(x5) & n_crowd(x4) & n_stand(x1) & of(x1,x2) & n_boy(x2) & a_sad(s1) & Theme(s1,x1))