Small schema with MULTIPLE INHERITANCE error

test_schema.exp

--    $ make p21read_sdai_TEST_SCHEMA
--    build\TEST_SCHEMA\SdaiTEST_SCHEMA.cc:337:65: error: 'class SdaiPerson_and_organization_address' has no member named 'people_'
--    Errors in input

SCHEMA test_schema;

TYPE classification_item = SELECT (
person_and_organization_address,
address);
END_TYPE;

TYPE label = STRING;
END_TYPE;

TYPE identifier = STRING;
END_TYPE;

TYPE text = STRING;
END_TYPE;

ENTITY person_and_organization_address
	SUBTYPE OF (organizational_address, personal_address);
	SELF\organizational_address.organizations : SET [1:1] OF organization;
	SELF\personal_address.people : SET [1:1] OF person;
END_ENTITY;

ENTITY personal_address
	SUBTYPE OF (address);
	people : SET [1:?] OF person;
	description : OPTIONAL text;
END_ENTITY;

ENTITY organizational_address
	SUBTYPE OF (address);
	organizations : SET [1:?] OF organization;
	description : OPTIONAL text;
END_ENTITY;

ENTITY organization;
	id : OPTIONAL identifier;
	name : label;
	description : OPTIONAL text;
END_ENTITY;

ENTITY address;
	internal_location : OPTIONAL label;
	street_number : OPTIONAL label;
	street : OPTIONAL label;
	postal_box : OPTIONAL label;
	town : OPTIONAL label;
	region : OPTIONAL label;
	postal_code : OPTIONAL label;
	country : OPTIONAL label;
	facsimile_number : OPTIONAL label;
	telephone_number : OPTIONAL label;
	electronic_mail_address : OPTIONAL label;
	telex_number : OPTIONAL label;
END_ENTITY;

ENTITY person;
	id : identifier;
	last_name : OPTIONAL label;
	first_name : OPTIONAL label;
	middle_names : OPTIONAL LIST [1:?] OF label;
	prefix_titles : OPTIONAL LIST [1:?] OF label;
	suffix_titles : OPTIONAL LIST [1:?] OF label;
WHERE
	WR1 : EXISTS(last_name) OR EXISTS(first_name);
END_ENTITY;

END_SCHEMA;