FunctionQName | ::= | (QNameToken | "ancestor" | "ancestor-or-self" | "and" | "as" | "cast" | "castable" | "child" | "descendant" | "descendant-or-self" | "div" | "doc" | "element-with-id" | "else" | "eq" | "every" | "except" | "following" | "following-sibling" | "for" | "ge" | "gt" | "id" | "idiv" | "in" | "instance" | "intersect" | "is" | "key" | "le" | "let" | "lt" | "mod" | "namespace" | "ne" | "of" | "or" | "parent" | "preceding" | "preceding-sibling" | "return" | "satisfies" | "self" | "some" | "then" | "to" | "treat" | "union") |