/*	File	:	part21_schema.pro
	Created	:	11/8/97
	
	Adaptation of example schema from IS0 10303:21 'Clear text encoding of the exchange structure
*/

/*	EXPRESS TYPE definitions are handled using the xpr1_type/4 predicate.
	xpr1_type(Schema, Type_ID, Base_Type, Where_Rules)
*/

/*
TYPE length_measure = NUMBER;
END_TYPE;
*/

xpr1_type(part21, length_measure, number, []) .

xpr1_type(part21, edge_or_logical, select(edge, edge_logical_structure), []) .

/*	
	EXPRESS ENTITY definitions are handled using the xpr1_entity/9 predicate.
	xpr1_entity(Schema, Entity_ID, Abstract, Super_Types, Sub_Types, Attributes, 
					Inverse, Unique, Where).
*/

/*
ENTITY cartesian_point;
  x_coordinate  : length_measure;
  y_coordinate  : length_measure;
  z_coordinate  : OPTIONAL length_measure;
END_ENTITY;
*/

xpr1_entity(part21, cartesian_point, not_abstract, [], [], 
	[	(x_coordinate, self, not_optional, length_measure),		% Explicit Attributes
		(y_coordinate, self, not_optional, length_measure),
		(z_coordinate, self, optional, length_measure)
	] ,
	[],		% Inverse
	[],		% Unique
	[]		% Where
	) .

xpr1_entity(part21, topology, not_abstract, [], [oneof(vertex, edge, loop)], 
	[], [], [], [] ) .

/*
ENTITY vertex
SUBTYPE OF (topology);
  vertex_point : OPTIONAL cartesian_point;
END_ENTITY;
*/

xpr1_entity(part21, vertex, not_abstract, [topology], [], 
	[	(vertex_point, self, optional, point)
	],
	[], [], [] ) .

/*
ENTITY edge
SUBTYPE OF (topology);
  edge_start   : vertex;
  edge_end     : vertex;
END_ENTITY;
*/

xpr1_entity(part21, edge, not_abstract, [topology], [], 
	[	(edge_start, self, not_optional, vertex),
		(edge_end, self, not_optional, vertex)
	],
	[], [], [] ) .

/*
ENTITY edge_logical_structure;
  edge_element : edge;
  flag : BOOLEAN;
END_ENTITY;
*/

xpr1_entity(part21, edge_logical_structure, not_abstract, [topology], [], 
	[	(edge_element, self, not_optional, edge),
		(flag, self, not_optional, boolean)
	],
	[], [], [] ) .

/*
ENTITY loop
SUPERTYPE OF (ONEOF(edge_loop))
SUBTYPE OF (topology);
END_ENTITY;
*/

xpr1_entity(part21, loop, not_abstract, [topology], [oneof(edge_loop)], 
	[], [], [], [] ) .

/*
ENTITY edge_loop
SUBTYPE OF (loop);
  loop_edges : LIST [1:?] OF edge_or_logical;
END_ENTITY;
*/

xpr1_entity(part21, edge_loop, not_abstract, [loop], [], 
	[	(loop_edges, self, not_optional, list(1, '?', edge_or_logical))
	],
	[], [], [] ) .