+let regexp nreference =
+ "cic:/" (* schema *)
+ uri_step ('/' uri_step)* (* path *)
+ '.'
+ ( "dec"
+ | "def" "(" number ")"
+ | "fix" "(" number "," number "," number ")"
+ | "cfx" "(" number ")"
+ | "ind" "(" number "," number "," number ")"
+ | "con" "(" number "," number "," number ")") (* ext + reference *)
+