Tourists mingle on a street.
People are on a street.
Tourists are people.
exists e1 x1 x2.(on(e1,x2) & n_street(x2) & Actor(e1,x1) & v_mingle(e1) & n_tourist(x1))
exists p1 x1.(exists x2.(on(x1,x2) & n_street(x2)) & n_people(x1))