OperationParameterPropertyType Operation parameters and groups .1 GeneralOperationParameter

138 Copyright © 2007 Open Geospatial Consortium, Inc. All Rights Reserved. NOTE 2 The corresponding topology schema document, topology.xsd see Annex C, is identified by the following location- independent name using URN syntax: urn:x-ogc:specification:gml:schema-xsd:topology:3.2.1 There are four instantiable classes of primitive topology objects, one for each dimension up to 3D. In addition, topology complexes are supported. There is strong symmetry in the topological boundary and coboundary relationships between topology primitives of adjacent dimensions. Topology primitives are bounded by directed primitives of one lower dimension. The coboundary of each topology primitive is formed from directed topology primitives of one higher dimension.

13.1.2 Relationship with ISO 19107

The spatial topology components of the GML schema specified in this clause provide a conformant, partial implementation of the ISO 19107 spatial schema topology. The relationship is discussed in detail in D.2.3. The ISO 19107 topology types implemented in GML are specified in ISO 19107; some additional constraints are specified in ISO 19107 for these types, which are also constraints on the spatial topology components of the GML schema. In addition, GML specifies complementary spatial topology schema components as described in D.3.10.

13.2 Abstract topology

complexType name=AbstractTopologyType abstract=true complexContent extension base=gml:AbstractGMLType complexContent complexType element name=AbstractTopology type=gml:AbstractTopologyType abstract=true substitutionGroup=gml:AbstractGML This abstract type supplies the root or base type for all topological elements including primitives and complexes. It inherits AbstractGMLType and hence can be identified using the gml:id attribute. gml:AbstractTopology implements ISO 19107 TP_Object see D.2.4.2 and ISO 19107:2003, 7.2.2.

13.3 Topological primitives

13.3.1 Abstract topological primitives 13.3.1.1 AbstractTopoPrimitive, AbstractTopoPrimtive complexType name=AbstractTopoPrimitiveType abstract=true complexContent extension base=gml:AbstractTopologyType sequence extension complexContent complexType element name=AbstractTopoPrimitive type=gml:AbstractTopoPrimitiveType abstract=true substitutionGroup=gml:AbstractTopology