premise: A man looks back while laughing and walking.
hypothesis: A man is looks behind his shoulder to laugh.
explanation_1: A man looks behind his shoulder to laugh while also walking.
explanation_2: "Looks behind his shoulder" is a rephrasing of "looks back.
explanation_3: The man looks back is the same as the man looks behind.
premise_logic: exists e2 e1 e3 p1 x1.(while(e1,e3) & Actor(e3,x1) & v_walk(e3) & while(e1,e2) & Actor(e2,x1) & v_laugh(e2) & exists s1.(Theme(s1,x1) & a_back(s1)) & Topic(e1,p1) & Actor(e1,x1) & v_look(e1) & n_man(x1))
hypothesis_logic: exists e2 e1 x1 x2 x3 x4.(behind(e2,x4) & n_shoulder(x4) & of(x4,x1) & n_male(x1) & to(e2,x3) & n_laugh(x3) & Actor(e2,x1) & v_look(e2) & Actor(e1,x2) & v_be(e1) & (x1 = x2) & n_man(x1))