A Membership_of_property_distribution_space is a Classification that is between a Possession_of_property and a Property_distribution and that indicates the Possession_of_property is a member of the Property_distribution.
EXPRESS specification:
*) ENTITY Membership_of_property_distribution SUBTYPE OF (Classification); class : Property_distribution; member : Possession_of_property; END_ENTITY; (*
Attribute definitions:
class: the Property_distribution that has the member.
member: the Possession_of_property that is a member of the class.