Extensible select and enumeration types

and their elements in schema Envelope_arm taking into account BASED_ON types


 activity_item - EXTENSIBLE GENERIC_ENTITY SELECT
          Applied_state_definition_assignment

 approval_item - EXTENSIBLE GENERIC_ENTITY SELECT
          Envelope
          Message

 classification_item - EXTENSIBLE GENERIC_ENTITY SELECT
          Applied_state_assignment
          Applied_state_definition_assignment
          State
          State_definition
          State_definition_relationship
          State_relationship

 date_or_date_time_item - EXTENSIBLE SELECT
          Envelope
          Message

 identification_item - EXTENSIBLE SELECT
          State_definition
          State_definition_relationship

 measure_value - EXTENSIBLE SELECT
          any_number_value
          any_string_value
          length_measure
          plane_angle_measure

 message_definer_select - EXTENSIBLE SELECT
          Organization
          Person_in_organization

 organization_or_person_in_organization_item - EXTENSIBLE SELECT
          Envelope

 property_assignment_select - EXTENSIBLE SELECT
          Envelope

 represented_definition - EXTENSIBLE SELECT
          Assigned_property
          Independent_property

 security_classification_item - EXTENSIBLE SELECT
          Message

 state_definition_of_item - EXTENSIBLE GENERIC_ENTITY SELECT

 state_of_item - EXTENSIBLE GENERIC_ENTITY SELECT
          Message