premise: A man in a blue helmet jumping off of a hill on a dirt bike.
hypothesis: The man is a professional athlete.
explanation_1: We don't know that he is a professional athlete.
explanation_2: Sentence 2 lets us know that the man in the helmet is not only jumping off a hill on a dirt bike but that he is a professional athlete doing so.
explanation_3: Just because he is jumping off of a hill does not mean he is a professional athlete.
premise_logic: exists e1 s1 x1 x2 x3 x4 x5 x6.(a_topic(x1) & in(x1,x2) & of(e1,x4) & on(x4,x5) & n_bike(x5) & of(x5,x6) & n_dirt(x6) & n_hill(x4) & r_off(e1) & Actor(e1,x3) & v_jump(e1) & (x2 = x3) & n_helmet(x2) & a_blue(s1) & Theme(s1,x2) & n_man(x1))
hypothesis_logic: exists p1 x1.(n_man(x1) & exists s1 x2.((x1 = x2) & n_athlete(x2) & a_professional(s1) & Theme(s1,x2)))