A cashier at a grocery store.
A cashier is at a drug store
He is either at the grocery store or at a drug store.
exists x1 x2 x3.(a_topic(x1) & at(x1,x2) & n_store(x2) & of(x2,x3) & n_grocery(x3) & n_cashier(x1))
exists p1 x1.(exists x2 x3.(at(x1,x2) & n_store(x2) & of(x2,x3) & n_drug(x3)) & n_cashier(x1))