premise: An old man holds up a sign.
hypothesis: A man is holding a sign.
explanation_1: If a man is holding up a sign, he must be holding a sign.
explanation_2: An old man is still a man, and a sign is a sign.
explanation_3: An old man is a man.
premise_logic: exists e1 s1 s2 x1 x2.(a_up(s2) & Manner(e1,s2) & Theme(e1,x2) & Actor(e1,x1) & v_hold(e1) & n_sign(x2) & n_man(x1) & a_old(s1) & Theme(s1,x1))
hypothesis_logic: exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_hold(e1) & n_sign(x2) & n_man(x1))