Re: querying RDF lists

One small corollary: special cases are possible with custom fucntions.

 > (a) a standard function (or some other mechanism) for querying whether some 
 > node is an element of some RDF list (i.e. something like isElementOfList(A, 
 > B))
 >
 >... and preferably also ...
 >
 >(b)  a standard function (or some other mechanism) for returning the
 >numerical position of a node in an RDF list (i.e. something like
 > listPosition(A, B))

In the special case where A and B to be bound or constant,
you might be able to write a custom filter function because the function just 
returns a boolean or integer.  Depends on the implementation.

The thing you can't do in a custom function would be to associate multiple 
possible values to variables.

	Andy