Problem:
 app(nil(),YS) -> YS
 app(cons(X,XS),YS) -> cons(X,app(XS,YS))
 from(X) -> cons(X,from(s(X)))
 zWadr(nil(),YS) -> nil()
 zWadr(XS,nil()) -> nil()
 zWadr(cons(X,XS),cons(Y,YS)) -> cons(app(Y,cons(X,nil())),zWadr(XS,YS))
 prefix(L) -> cons(nil(),zWadr(L,prefix(L)))

Proof:
 Containment Processor: loop length: 1
                        terms:
                         from(X)
                        context: cons(X,[])
                        substitution:
                         X -> s(X)
  Qed