premise: A skateboarding youth does a trick on a rail.
hypothesis: A young person on a skateboard.
explanation_1: Skateboarding youth implies a young person.  A skateboarding youth must be on a skateboard in order to do a trick on a rail.
explanation_2: Youth describes a young person. A young person is skateboarding, so they must be on a skateboard.
explanation_3: you have to get on the skate board before doing tricks
premise_logic: exists e2 e1 x1 x2 x3.(on(e2,x3) & n_rail(x3) & Theme(e2,x2) & Actor(e2,x1) & v_do(e2) & n_trick(x2) & n_youth(x1) & Actor(e1,x1) & v_skateboard(e1))
hypothesis_logic: exists s1 x1 x2.(a_topic(x1) & on(x1,x2) & n_skateboard(x2) & n_person(x1) & a_young(s1) & Theme(s1,x1))
premise_sim: exists e2 e1 x1 x2 x3.(v_skateboard(e1) & v_do(e2) & on(e2,x3) & n_youth(x1) & n_trick(x2) & n_rail(x3) & Theme(e2,x2) & Actor(e2,x1) & Actor(e1,x1))
hypothesis_sim: exists s1 x1 x2.(on(x1,x2) & n_skateboard(x2) & n_person(x1) & a_young(s1) & a_topic(x1) & Theme(s1,x1))