Hi Jennie, hi Peter, I am currently looking into the XRPC syntax. Primarily I wanted to give you feedback to what you wrote in your Plan-X submission. So you are defining the syntax to be XRPCCall ::= "execute" "at" URILiteral FunctionCall Lateron, however, you allow more than just a literal URI, but rather an XQuery expression. So `URILiteral' is definitely wrong here. Once you changed this to, say, ExprSingle, you end up with ambiguity in your parser. Consider execute at "foo" eq ("bar") (I couldn't think of a better example ad hoc.) What we have here is an ambiguity: we don't know whether `eq' is supposed to be a function call, or if it is the binary operator `eq', followed by another expression in parenthesis. So I will take the freedom to modify your syntax proposal and do it in a more XQuery-like style: "execute" "at" "{" Expr "}" "{" FunctionCall "}" This avoids the ambiguity and should make it rather easy to parse. ...already hacking... Jens -- Jens Teubner Technische Universitaet Muenchen, Department of Informatics D-85748 Garching, Germany Tel: +49 89 289-17259 Fax: +49 89 289-17263 Time is money. Especially if you make clocks.