src/Pure/General/scan.ML

 
 (* trace input *)
 
 fun trace scan xs =
   let val (y, xs') = scan xs
-  in ((y, (uncurry take) (length xs - length xs', xs)), xs') end;
+  in ((y, take (length xs - length xs') xs), xs') end;
 
 
 (* stopper *)
 
 datatype 'a stopper = Stopper of ('a list -> 'a) * ('a -> bool);