<?xml version='1.0' encoding='UTF-8'?>

<!ELEMENT gps-device (load*, tick-generator, gps-locator, navigation-display*)>

<!ELEMENT load EMPTY>
<!ATTLIST load library			CDATA #REQUIRED>

<!ELEMENT gps-locator EMPTY>
<!ATTLIST gps-locator use 		CDATA #REQUIRED>

<!ELEMENT tick-generator EMPTY>
<!ATTLIST tick-generator use		CDATA #REQUIRED>
<!ATTLIST tick-generator count		CDATA #REQUIRED>
<!ATTLIST tick-generator interval	CDATA #REQUIRED>

<!ELEMENT navigation-display EMPTY>
<!ATTLIST navigation-display use	CDATA #REQUIRED>