Customers walk about a grocery store.
People are inside a building
Customers are people and a grocery store is inside a building.
exists e1 x1 x2 x3.(about(e1,x2) & n_store(x2) & of(x2,x3) & n_grocery(x3) & Actor(e1,x1) & v_walk(e1) & n_customer(x1))
exists p1 x1.(exists x2.(inside(x1,x2) & n_building(x2)) & n_people(x1))