People in costumes are walking around in the street.
A group of children are trick or treating for Halloween.
Not all people are children. People in costumes walking around in the street are not necessarily doing trick or treating for Halloween.
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 x3 x6.(ne_geo_halloween(x6) & ne_geo_halloween(x3) & (exists s1 x1 x2.(for(s1,x3) & Theme(s1,x1) & a_trick(s1) & of(x1,x2) & n_child(x2) & n_group(x1)) | exists s2 x4 x5.(for(s2,x6) & Theme(s2,x4) & a_treat(s2) & of(x4,x5) & n_child(x5) & n_group(x4))))