src/Pure/library.ML

   val oooo: ('a -> 'b) * ('c -> 'd -> 'e -> 'f -> 'a) -> 'c -> 'd -> 'e -> 'f -> 'b
   val funpow: int -> ('a -> 'a) -> 'a -> 'a
   val funpow_yield: int -> ('a -> 'b * 'a) -> 'a -> 'b list * 'a
 
   (*errors*)
-  exception SYS_ERROR of string
-  val sys_error: string -> 'a
   exception ERROR of string
   val error: string -> 'a
   val cat_error: string -> string -> 'a
   val assert_all: ('a -> bool) -> 'a list -> ('a -> string) -> unit
 

   | funpow n f = f #> funpow (n - 1) f;
 
 fun funpow_yield (0 : int) _ x = ([], x)
   | funpow_yield n f x = x |> f ||>> funpow_yield (n - 1) f |>> op ::;
 
+
 (* errors *)
-
-exception SYS_ERROR of string;
-fun sys_error msg = raise SYS_ERROR msg;
 
 exception ERROR of string;
 fun error msg = raise ERROR msg;
 
 fun cat_error "" msg = error msg