public Ab<E> fillDret() throws ArbreException {
if (this.arrel == null) throw new ArbreException("Ab buit no te fills");
AbEnll<E> retorn = new AbEnll<E>();
retorn.arrel = this.arrel.dret;
return retorn;
}
public Ab<E> fillEsquerre() throws ArbreException {
if (this.arrel == null) throw new ArbreException("Ab buit no te fills");
AbEnll<E> resultat = new AbEnll<E>();
resultat.arrel = this.arrel.esq;
return resultat;
}