Derivation by restriction from complexType/simpleContent

What is the correct syntax for derivation from complexType/simpleContent
types?
For example, if I write

<complexType name="MeasureType">
	<simpleContent>
		<extension base="double">
			<attribute name="uom" type="token"
use="required"/>
		</extension>
	</simpleContent>
</complexType>

<complexType name="LengthType">
	<simpleContent>
		<restriction base="gml:MeasureType"/>
	</simpleContent>
</complexType>

1. Is the "double" simpleContent preserved or not?
2. Is there any way I can restrict the value of uom?

Simon Cox
______
Simon.Cox@csiro.au  CSIRO Exploration & Mining
26 Dick Perry Avenue, Kensington WA 6151
PO Box 1130, Bentley WA 6102  AUSTRALIA
T: +61(8) 6436 8639  F: +61(8) 6436 8555  
C: +61(4) 0330 2672 callto://dr_shorthair 
http://www.em.csiro.au 
  

Received on Thursday, 2 December 2004 10:37:31 UTC