A person standing outside is using an umbrella in the heavy rain.
Someone is standing on the sidewalk.
Standing outside does not imply being on the sidewalk.
exists e1 e2 s1 x1 x2 x3 x4 x5.(n_rain(x5) & a_heavy(s1) & Theme(s1,x5) & in(e2,x5) & Theme(e2,x4) & Actor(e2,x1) & v_use(e2) & n_umbrella(x4) & Time(e1,x3) & n_outside(x3) & Actor(e1,x2) & v_stand(e1) & (x1 = x2) & n_person(x1))
exists e1 x1 x2.(n_sidewalk(x2) & on(e1,x2) & Actor(e1,x1) & v_stand(e1) & n_person(x1))