<xs:element name="LandXML">
    <xs:complexType>
        <xs:choice maxOccurs="unbounded">
            <xs:element ref="Units" />
            <xs:element ref="CoordinateSystem" minOccurs="0" />
            <xs:element ref="Project" minOccurs="0" />
            <xs:element ref="Application" minOccurs="0" maxOccurs="unbounded" />
            <xs:element ref="Alignments" minOccurs="0" maxOccurs="unbounded" />
            <xs:element ref="CgPoints" minOccurs="0" maxOccurs="unbounded" />
            <xs:element ref="Amendment" minOccurs="0" maxOccurs="unbounded" />
            <xs:element ref="GradeModel" minOccurs="0" maxOccurs="unbounded" />
            <xs:element ref="Monuments" minOccurs="0" maxOccurs="unbounded" />
            <xs:element ref="Parcels" minOccurs="0" maxOccurs="unbounded" />
            <xs:element ref="PlanFeatures" minOccurs="0" maxOccurs="unbounded" />
            <xs:element ref="PipeNetworks" minOccurs="0" maxOccurs="unbounded" />
            <xs:element ref="Roadways" minOccurs="0" maxOccurs="unbounded" />
            <xs:element ref="Surfaces" minOccurs="0" maxOccurs="unbounded" />
            <xs:element ref="Survey" minOccurs="0" maxOccurs="unbounded" />
            <xs:any namespace="##other" processContents="skip" minOccurs="0" />
        </xs:choice>
        <xs:attribute name="date" type="xs:date" use="required" />
        <xs:attribute name="time" type="xs:time" use="required" />
        <xs:attribute name="version" type="xs:string" use="required" />
        <xs:attribute name="language" type="xs:string" />
        <xs:attribute name="readOnly" type="xs:boolean" />
        <xs:attribute name="LandXMLId" type="xs:int" />
        <xs:attribute name="crc" type="xs:integer" />
    </xs:complexType>
    <xs:unique name="uCoordGeomName">
        <xs:selector xpath="CoordGeom" />
        <xs:field xpath="@name" />
    </xs:unique>
    <xs:unique name="uCgPointsName">
        <xs:selector xpath="CgPoints" />
        <xs:field xpath="@name" />
    </xs:unique>
    <xs:unique name="uRoadwayName">
        <xs:selector xpath="Roadways/Roadway" />
        <xs:field xpath="@name" />
    </xs:unique>
    <xs:unique name="uGradeModelName">
        <xs:selector xpath="GradeModel" />
        <xs:field xpath="@name" />
    </xs:unique>
    <xs:key name="MonumentKey">
        <xs:selector xpath=".//Monuments/Monument" />
        <xs:field xpath="@name" />
    </xs:key>
    <xs:keyref name="SurveyMonument" refer="MonumentKey">
        <xs:selector xpath=".//SurveyMonument" />
        <xs:field xpath="@mntRef" />
    </xs:keyref>
    <xs:key name="StructKey">
        <xs:selector xpath=".//PipeNetwork/*/Struct" />
        <xs:field xpath="@name" />
    </xs:key>
    <xs:keyref name="PipeStart" refer="StructKey">
        <xs:selector xpath=".//PipeNetwork/*/Pipe" />
        <xs:field xpath="@refStart" />
    </xs:keyref>
    <xs:keyref name="PipeEnd" refer="StructKey">
        <xs:selector xpath=".//PipeNetwork/*/Pipe" />
        <xs:field xpath="@refEnd" />
    </xs:keyref>
    <xs:key name="PipeKey">
        <xs:selector xpath=".//PipeNetwork/*/Pipe" />
        <xs:field xpath="@name" />
    </xs:key>
    <xs:keyref name="StructInvert" refer="PipeKey">
        <xs:selector xpath=".//PipeNetwork/*/Struct/Invert" />
        <xs:field xpath="@refPipe" />
    </xs:keyref>
    <xs:key name="ReducedObservationName">
        <xs:selector xpath=".//*/ObservationGroup/*/ReducedObservation" />
        <xs:field xpath="@name" />
    </xs:key>
    <xs:key name="ReducedArcObservationName">
        <xs:selector xpath=".//*/ObservationGroup/*/ReducedArcObservation" />
        <xs:field xpath="@name" />
    </xs:key>
    <xs:key name="Coord3DGeomName">
        <xs:selector xpath=".//Parcels/*/Coord3DGeom" />
        <xs:field xpath="@name" />
    </xs:key>
    <xs:key name="AnnotationName">
        <xs:selector xpath=".//Survey/*/Annotation" />
        <xs:field xpath="@name" />
    </xs:key>
    <xs:key name="SurveyorCertificateName">
        <xs:selector xpath=".//Survey/*/SurveyorCertificate" />
        <xs:field xpath="@name" />
    </xs:key>
</xs:element>