premise: Riot police are standing in the background while a young man with a red scarf covering his face is walking.
hypothesis: there are police
explanation_1: Riot police is part of the police
explanation_2: "There are police" conveys the same message as "police are standing."
explanation_3: Riot police are a type of police.
premise_logic: exists e1 p1 x1 x2 x3 x7.(n_face(x7) & of(x7,x3) & n_male(x3) & n_background(x3) & exists e3 e2 s1 s2 x4 x5 x6.(Actor(e3,x4) & v_walk(e3) & with(x4,x5) & Theme(e2,x7) & Actor(e2,x6) & v_cover(e2) & (x5 = x6) & n_scarf(x5) & a_red(s2) & Theme(s2,x5) & n_man(x4) & a_young(s1) & Theme(s1,x4)) & while(e1,p1) & in(e1,x3) & Actor(e1,x1) & v_stand(e1) & n_police(x1) & (x1 = x2) & ne_nam_riot(x2))
hypothesis_logic: exists p1 x1 x2.((x1 = x2) & n_police(x2))