renamed kill_all to kill, in conformance with atp_kill command;
simplified/unified treatment of preferences;
check_thread_manager: CRITICAL due to global ref;
goal addressing via Thm.cprem_of;
reduced NJ basis library stuff to bare minimum;
(* ID: $Id$ *)
use_thy "Examples";
use_thy "Functions";
use_thy "Relations";
use_thy "Recur";