Deriving various simpleContent and complexContent types from the same base?

Problem:  

1.  I want to define an abstract element <_Observation>, 
whose substitutionGroup includes elements such as 
  <Quantity> which has simple content of type xsd:double
  <Value> with simple content of type xsd:string
  <Count> with simple content of type xsd:nonNegativeInteger

e.g. Can I define an abstract base type with no content 
(complexType?), or of "anyType" (can this be a simpleType?), 
and then "restrict" the base to the various simpleTypes?

2.  Can I also derive e.g. <TwoQuantity> with complex content 
- a sequence of <Quantity> elements -  
by extension from the same base <_Observation> type?

e.g. Is it possible to extend a simpleType by inserting 
elements as a content model?


I've a feeling that the second case is easier than the first, 
but have been going round in circles on this and need some help!

-- 
Simon.Cox@dem.csiro.au    CSIRO Exploration & Mining
T:+61(8) 9284 8443 F:+61(8) 9389 1906 M:0403 302 672
http://www.ned.dem.csiro.au/research/visualisation/

Received on Wednesday, 21 February 2001 03:34:26 UTC