XPointer: Context initialization
An XPointer is basically an XPath expression occuring in a URI.
When evaluated, the initial context is defined as follows:
- The context node is the root node of the document.
- The context position and size are both 1.
- The variable bindings are empty.
- The function library consists of the core XPath functions
+ a few extra functions
- The namespace declarations are chosen to be the ones whose
scope contains the XPointer.