[FS]Is "XQuery Core grammar" a complete language?

Dear XQuery Formal semantic editor:
   
	I have some question about  XQuery/Xpath core grammar in "XQuery 1.0 and XPath 2.0 Formal Semantics" (2004-2-20).

	1)Some Non-Terminal only occur in the left side of core grammar production,but no Non-Terminal can yield it.
	  For example:
      	PrimaryExpr
	  	OrderByClause
      	QuantifiedExpr
      could you explain it in detail?

    2)In Formal semantic,OrderByClause can be normalized to nested let and for expressions,but why it still
       remain in the core grammar?

    3) In XQuery standard grammar:
		ExprSingle    ::=     FLWORExpr
							| QuantifiedExpr
							| TypeswitchExpr
							| IfExpr
							| OrExpr   
        In XQuery Core grammar:
         ExprSingle    ::=    FLWORExpr
							| TypeswitchExpr
							| IfExpr
							| OrExpr 
		QuantifiedExpr has been removed ,why?

   
    At last ,what is the purpose of "XQuery Core grammar"? 
      

		best regards
						liao wei

Received on Thursday, 26 February 2004 07:20:46 UTC