People in costumes are walking around in the street.
People dressed up are walking down a street.
People dressed up could be people in costumes. Walking down a street is a rephrasing of walking around in the street.
exists e1 p1 x1 x2 x3.(n_street(x3) & in(e1,x3) & exists s1.(Theme(s1,x1) & a_around(s1)) & Topic(e1,p1) & Actor(e1,x1) & v_walk(e1) & in(x1,x2) & n_costume(x2) & n_people(x1))
exists e1 e2 s1 x1 x2 x3.(down(e2,x3) & n_street(x3) & Actor(e2,x1) & v_walk(e2) & a_up(s1) & Manner(e1,s1) & Theme(e1,x2) & v_dress(e1) & (x1 = x2) & n_people(x1))