more explicit indication of Output.Private_Hooks (still public to accomodate clones of Proof General for now);
(* Title: HOL/Metis_Examples/ROOT.ML
Author: Lawrence C Paulson, Cambridge University Computer Laboratory
Testing the metis method.
*)
use_thys ["set", "BigO", "Abstraction", "BT", "Message", "Tarski", "TransClosure"];