let find_info idx key =
match key with
| Key.SigKey k -> Signature.find_info idx.sgn k
| Key.CallStmt _ -> raise CallStatement (* see find_info_call *)
| Key.SigCallKey (call, k) -> find_info_sig_call idx call k
| Key.VarDecl _ | Key.Stmt _ | Key.Label _ ->
(try H.find idx.other (Hkey.hkey key)
with Not_found -> raise Not_found)