premise: A skateboarder goes down a railing.
hypothesis: A skateboarder finally succeeds in going down a railing after many tries.
explanation_1: The fact that skateboarder  goes down a railing does not imply that he succeeded in doing so only after many tries.
explanation_2: Goes down a railing doesn't imply skateboarder did it after many tries.
explanation_3: Sentence 1 doesn't say the skateboarder has ever tried going down a railing before the current time. Therefore we don't know that he's only accomplished this after many tries.
premise_logic: exists e1 s1 x1 x2.(a_down(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_go(e1) & n_railing(x2) & n_skateboarder(x1))
hypothesis_logic: exists e1 e2 s1 s2 x1 x2 x3.(in(e1,e2) & after(e2,x3) & n_try(x3) & n_quantity(x3) & a_down(s2) & Manner(e2,s2) & Theme(e2,x2) & Actor(e2,x1) & v_go(e2) & n_railing(x2) & a_finally(s1) & Manner(e1,s1) & Actor(e1,x1) & v_succeed(e1) & n_skateboarder(x1))