People walking in the rain.
People walking outside.
Walking in the rain obviously means walking outside.
exists e1 x1 x2 x3.(n_rain(x3) & a_topic(x1) & in(e1,x3) & Actor(e1,x2) & v_walk(e1) & (x1 = x2) & n_people(x1))
exists e1 s1 x1 x2.(a_topic(x1) & a_outside(s1) & Manner(e1,s1) & Actor(e1,x2) & v_walk(e1) & (x1 = x2) & n_people(x1))