;--------------------------------- contact ------------------------------------
<preguntas_contact> -> (
   <pregunta_contact> | <pregunta_person> | <pregunta_organization>
)
<cont_preguntas_contact> -> (
   <cont_pregunta_person> | <cont_pregunta_organization>
)
<pregunta_contact> -> (
   where (can | could) I find maps
)
<pregunta_person> -> (
   who is <cont_pregunta_person> ?(of ?all ?the maps)
)
<cont_pregunta_person> -> (
   the ?(name of the) ?contact person
)
<pregunta_organization> -> (
   who is <cont_pregunta_organization> ?(of ?all ?the maps)
)
<cont_pregunta_organization> -> (
   the ?(name of the) ?contact organization
)
<atributos_inf_contact> -> (
   nil
)
<atributos_pregunta_contact> -> (
   ?contact position | 
   (address | email | telephone number | fax ?telephone) ?(of contact) | 
   city | state | postal code | country | 
   (voice | TDD | TTY) telephone ?number | hour ?(of service)
)