Man, son, and vendor smile while holding souvenir magazines.
The group of people seem to be happy.
Man, son, and vendor are a group of people, and smile implies happy.
exists e1 e2 x1 x2 x3 x4 x5 x6.(while(e1,e2) & Theme(e2,x5) & Actor(e2,x1) & v_hold(e2) & n_magazine(x5) & of(x5,x6) & n_souvenir(x6) & Actor(e1,x1) & v_smile(e1) & rel(x1,x2) & subset_of(x4,x2) & n_vendor(x4) & subset_of(x3,x2) & n_son(x3) & n_man(x1))
exists e1 p1 x1 x2.(n_group(x1) & Topic(e1,p1) & Actor(e1,x1) & v_seem(e1) & exists s1.(Theme(s1,x1) & a_happy(s1)) & of(x1,x2) & n_people(x2))