diff --git a/C/exec.c b/C/exec.c
index deab9ddcd..0638134e3 100755
--- a/C/exec.c
+++ b/C/exec.c
@@ -113,7 +113,7 @@ static inline bool CallPredicate(PredEntry *pen, choiceptr cut_pt,
  * @return              did we fiid it?
  */
 inline static bool CallMetaCall(Term t, Term mod USES_REGS) {
-  // we have a creep requesr waiting
+   // we have a creep requesr waiting
 
   ARG1 = t;
   ARG2 = cp_as_integer(B PASS_REGS); /* p_current_choice_point */
@@ -1009,7 +1009,6 @@ static bool complete_ge(bool out, Term omod, yhandle_t sl, bool creeping) {
 }
 
 static Int _user_expand_goal(USES_REGS1) {
-  BACKUP_MACHINE_REGS();
   yhandle_t sl = Yap_StartSlots();
   Int creeping = Yap_get_signal(YAP_CREEP_SIGNAL);
   PredEntry *pe;
@@ -1056,15 +1055,12 @@ static Int _user_expand_goal(USES_REGS1) {
            Yap_GetPredPropByFunc(FunctorGoalExpansion2, USER_MODULE))) &&
       pe->OpcodeOfPred != FAIL_OPCODE && pe->OpcodeOfPred != UNDEF_OPCODE &&
       Yap_execute_pred(pe, NULL PASS_REGS, false)) {
-    RECOVER_MACHINE_REGS();
     return complete_ge(true, omod, sl, creeping);
   }
-   RECOVER_MACHINE_REGS();
   return complete_ge(false, omod, sl, creeping);
 }
 
 static Int do_term_expansion(USES_REGS1) {
-  BACKUP_MACHINE_REGS();
   yhandle_t sl = Yap_StartSlots();
   Int creeping = Yap_get_signal(YAP_CREEP_SIGNAL);
   PredEntry *pe;
@@ -1079,7 +1075,6 @@ static Int do_term_expansion(USES_REGS1) {
            Yap_GetPredPropByFunc(FunctorTermExpansion, USER_MODULE))) &&
       pe->OpcodeOfPred != FAIL_OPCODE && pe->OpcodeOfPred != UNDEF_OPCODE &&
       Yap_execute_pred(pe, NULL, false PASS_REGS)) {
-   RECOVER_MACHINE_REGS();
     return complete_ge(true, omod, sl, creeping);
   }
   /* CurMod:term_expansion(A,B) */
@@ -1088,7 +1083,6 @@ static Int do_term_expansion(USES_REGS1) {
       (pe = RepPredProp(Yap_GetPredPropByFunc(FunctorTermExpansion, cmod))) &&
       pe->OpcodeOfPred != FAIL_OPCODE && pe->OpcodeOfPred != UNDEF_OPCODE &&
       Yap_execute_pred(pe, NULL, false PASS_REGS)) {
-   RECOVER_MACHINE_REGS();
     return complete_ge(true, omod, sl, creeping);
   }
   /* system:term_expansion(A,B) */
@@ -1100,10 +1094,8 @@ static Int do_term_expansion(USES_REGS1) {
            Yap_GetPredPropByFunc(FunctorTermExpansion, SYSTEM_MODULE))) &&
       pe->OpcodeOfPred != FAIL_OPCODE && pe->OpcodeOfPred != UNDEF_OPCODE &&
       Yap_execute_pred(pe, NULL, false PASS_REGS)) {
-   RECOVER_MACHINE_REGS();
     return complete_ge(true, omod, sl, creeping);
   }
-   RECOVER_MACHINE_REGS();
   return complete_ge(false, omod, sl, creeping);
 }
 
@@ -1667,6 +1659,7 @@ bool Yap_execute_pred(PredEntry *ppe, CELL *pt, bool pass_ex USES_REGS) {
   yamop *saved_p, *saved_cp;
   yamop *CodeAdr;
   bool out;
+
   saved_p = P;
   saved_cp = CP;
   LOCAL_PrologMode |= TopGoalMode;
diff --git a/C/utilpreds.c b/C/utilpreds.c
index 6562b9d93..185b09881 100644
--- a/C/utilpreds.c
+++ b/C/utilpreds.c
@@ -3002,9 +3002,9 @@ static Term non_singletons_in_complex_term(register CELL *pt0, register CELL *pt
 	CELL *pt2 = pt0;
 	while(IsVarTerm(*pt2))
 	  pt2 = (CELL *)(*pt2);
-	HR[1] = AbsPair(HR+2);
+	HR[0] = AbsPair(HR+2);
 	HR += 2;
-	HR[-2] = (CELL)pt2;
+	HR[-1] = (CELL)pt2;
 	*pt2 = TermRefoundVar;
       }
       continue;
@@ -3035,8 +3035,8 @@ static Term non_singletons_in_complex_term(register CELL *pt0, register CELL *pt
   clean_tr(TR0 PASS_REGS);
   if (HR != InitialH) {
     /* close the list */
-    RESET_VARIABLE(HR-1);
-    Yap_unify((CELL)(HR-1),ARG2);
+    RESET_VARIABLE(HR-2);
+    Yap_unify((CELL)(HR-2),ARG2);
     return output;
   } else {
     return ARG2;
@@ -3067,7 +3067,7 @@ p_non_singletons_in_term( USES_REGS1 )	/* non_singletons in term t		 */
   while (TRUE) {
     t = Deref(ARG1);
     if (IsVarTerm(t)) {
-      out = MkPairTerm(t,ARG2);
+      out = ARG2;
     }  else if (IsPrimitiveTerm(t)) {
       out = ARG2;
     } else if (IsPairTerm(t)) {
diff --git a/os/yio.yap b/os/yio.yap
index b37757a95..d2265ed6a 100644
--- a/os/yio.yap
+++ b/os/yio.yap
@@ -181,7 +181,7 @@ display(Stream, T) :-
 /* interface to user portray	*/
 '$portray'(T) :-
 	\+ '$undefined'(portray(_),user),
-	'$system_catch'(call(portray(T)),user,Error,user:'$Error'(Error)), !,
+	catch(user:portray(T),Error,'$Error'(Error)), !,
 	set_value('$portray',true), fail.
 '$portray'(_) :- set_value('$portray',false), fail.
 
diff --git a/pl/absf.yap b/pl/absf.yap
index dbfbb467b..781b71b48 100755
--- a/pl/absf.yap
+++ b/pl/absf.yap
@@ -164,13 +164,13 @@ absolute_file_name(File0,File) :-
      % look for solutions
      gated_call(
 
-        '$sys':enter_absf( File, LOpts, Opts, HasSol, OldF, PreviousFileErrors, PreviousVerbose, Expand, Verbose, TakeFirst, FileErrors ),
-         '$sys':find_in_path(File, Opts,TrueFileName, HasSol, TakeFirst),
+        '$enter_absf'( File, LOpts, Opts, HasSol, OldF, PreviousFileErrors, PreviousVerbose, Expand, Verbose, TakeFirst, FileErrors ),
+         '$find_in_path'(File, Opts,TrueFileName, HasSol, TakeFirst),
          Port,
-     '$sys':absf_port(Port, File, TrueFileName, HasSol, OldF, PreviousFileErrors, PreviousVerbose, Expand, Verbose, TakeFirst, FileErrors )
+     '$absf_port'(Port, File, TrueFileName, HasSol, OldF, PreviousFileErrors, PreviousVerbose, Expand, Verbose, TakeFirst, FileErrors )
 	).
 
-'$sys':enter_absf( File, LOpts, Opts, HasSol, OldF, PreviousFileErrors, PreviousVerbose, Expand, Verbose, TakeFirst, FileErrors ) :-
+'$enter_absf'( File, LOpts, Opts, HasSol, OldF, PreviousFileErrors, PreviousVerbose, Expand, Verbose, TakeFirst, FileErrors ) :-
 	( var(File) -> instantiation_error(File) ; true),
 	abs_file_parameters(LOpts,Opts),
 	current_prolog_flag(open_expands_filename, OldF),
@@ -188,20 +188,20 @@ absolute_file_name(File0,File) :-
 	'$absf_trace_options'(LOpts),
     HasSol = t(no).
 
-'$sys':absf_port(answer, File, TrueFileName, HasSol, OldF, PreviousFileErrors, PreviousVerbose, Expand, Verbose, TakeFirst, FileErrors ) :-
-            '$sys':absf_port(exit, File, TrueFileName, HasSol, OldF, PreviousFileErrors, PreviousVerbose, Expand, Verbose, TakeFirst, FileErrors ).
-'$sys':absf_port(exit, _File, TrueFileName, HasSol, OldF, PreviousFileErrors, PreviousVerbose, _Expand, _Verbose, TakeFirst, _FileErrors ) :-
+'$absf_port'(answer, File, TrueFileName, HasSol, OldF, PreviousFileErrors, PreviousVerbose, Expand, Verbose, TakeFirst, FileErrors ) :-
+            '$absf_port'(exit, File, TrueFileName, HasSol, OldF, PreviousFileErrors, PreviousVerbose, Expand, Verbose, TakeFirst, FileErrors ).
+'$absf_port'(exit, _File, TrueFileName, HasSol, OldF, PreviousFileErrors, PreviousVerbose, _Expand, _Verbose, TakeFirst, _FileErrors ) :-
     (TakeFirst == first -> ! ; nb_setarg(1, HasSol, yes) ),
     set_prolog_flag( fileerrors, PreviousFileErrors ),
     set_prolog_flag( open_expands_filename, OldF),
     set_prolog_flag( verbose_file_search, PreviousVerbose ),
     '$absf_trace'(' |------- found  ~a', [TrueFileName]).
-'$sys':absf_port(redo, File, _TrueFileName, _HasSol, _OldF, _PreviousFileErrors, _PreviousVerbose, Expand, Verbose, _TakeFirst, FileErrors ) :-
+'$absf_port'(redo, File, _TrueFileName, _HasSol, _OldF, _PreviousFileErrors, _PreviousVerbose, Expand, Verbose, _TakeFirst, FileErrors ) :-
     set_prolog_flag( fileerrors, FileErrors ),
     set_prolog_flag( verbose_file_search, Verbose ),
     set_prolog_flag( file_name_variables, Expand ),
     '$absf_trace'(' |------- restarted search for  ~a', [File]).
-'$sys':absf_port(fail, File, TrueFileName, HasSol, OldF, PreviousFileErrors, PreviousVerbose, _Expand, _Verbose, _TakeFirst, FileErrors ) :-
+'$absf_port'(fail, File, TrueFileName, HasSol, OldF, PreviousFileErrors, PreviousVerbose, _Expand, _Verbose, _TakeFirst, FileErrors ) :-
     '$absf_trace'(' !------- failed.', []),
     set_prolog_flag( fileerrors, PreviousFileErrors ),
     set_prolog_flag( verbose_file_search, PreviousVerbose ),
@@ -210,22 +210,22 @@ absolute_file_name(File0,File) :-
     arg(1,HasSol,no),
     FileErrors = error,
     '$do_error'(existence_error(file,File),absolute_file_name(File, TrueFileName, ['...'])).
-'$sys':absf_port(!, _File, _TrueFileName, _HasSol, _OldF, _PreviousFileErrors, _PreviousVerbose, _Expand, _Verbose, _TakeFirst, _FileErrors ).
-'$sys':absf_port(exception(_), File, TrueFileName, HasSol, OldF, PreviousFileErrors, PreviousVerbose, Expand, Verbose, TakeFirst, FileErrors ) :-
-    '$sys':absf_port(fail, File, TrueFileName, HasSol, OldF, PreviousFileErrors, PreviousVerbose, Expand, Verbose, TakeFirst, FileErrors ).
-'$sys':absf_port(external_exception(_),  File, TrueFileName, HasSol, OldF, PreviousFileErrors, PreviousVerbose, Expand, Verbose, TakeFirst, FileErrors ) :-
-    '$sys':absf_port(fail,  File, TrueFileName, HasSol, OldF, PreviousFileErrors, PreviousVerbose, Expand, Verbose, TakeFirst, FileErrors ).
+'$absf_port'(!, _File, _TrueFileName, _HasSol, _OldF, _PreviousFileErrors, _PreviousVerbose, _Expand, _Verbose, _TakeFirst, _FileErrors ).
+'$absf_port'(exception(_), File, TrueFileName, HasSol, OldF, PreviousFileErrors, PreviousVerbose, Expand, Verbose, TakeFirst, FileErrors ) :-
+    '$absf_port'(fail, File, TrueFileName, HasSol, OldF, PreviousFileErrors, PreviousVerbose, Expand, Verbose, TakeFirst, FileErrors ).
+'$absf_port'(external_exception(_),  File, TrueFileName, HasSol, OldF, PreviousFileErrors, PreviousVerbose, Expand, Verbose, TakeFirst, FileErrors ) :-
+    '$absf_port'(fail,  File, TrueFileName, HasSol, OldF, PreviousFileErrors, PreviousVerbose, Expand, Verbose, TakeFirst, FileErrors ).
 
 % This sequence must be followed:
 % user and user_input are special;
 % library(F) must check library_directories
 % T(F) must check file_search_path
 % all must try search in path
- '$sys':find_in_path(user,_,user_input,  _, _) :- !.
- '$sys':find_in_path(user_input,_,user_input, _, _) :- !.
- '$sys':find_in_path(user_output,_,user_ouput, _, _) :- !.
- '$sys':find_in_path(user_error,_,user_error, _, _) :- !.
- '$sys':find_in_path(Name, Opts, File, _, First) :-
+'$find_in_path'(user,_,user_input,  _, _) :- !.
+'$find_in_path'(user_input,_,user_input, _, _) :- !.
+'$find_in_path'(user_output,_,user_ouput, _, _) :- !.
+'$find_in_path'(user_error,_,user_error, _, _) :- !.
+'$find_in_path'(Name, Opts, File, _, First) :-
     %    (	atom(Name) -> true ; start_low_level_trace ),
 	get_abs_file_parameter( file_type, Opts, Type ),
     get_abs_file_parameter( access, Opts, Access ),
diff --git a/pl/boot.yap b/pl/boot.yap
index ffc7c7697..690ae8834 100644
--- a/pl/boot.yap
+++ b/pl/boot.yap
@@ -50,7 +50,30 @@ private(_).
         (not)/1,
         repeat/0,
         throw/1,
-        true/0], []).
+        true/0], ['$$compile'/4,
+        '$call'/4,
+        '$catch'/3,
+        '$check_callable'/2,
+        '$check_head_and_body'/4,
+        '$check_if_reconsulted'/2,
+        '$clear_reconsulting'/0,
+        '$command'/4,
+        '$cut_by'/1,
+        '$disable_debugging'/0,
+        '$do_live'/0,
+        '$'/0,
+        '$find_goal_definition'/4,
+        '$head_and_body'/3,
+        '$inform_as_reconsulted'/2,
+        '$init_system'/0,
+        '$init_win_graphics'/0,
+        '$loop'/2,
+        '$meta_call'/2,
+        '$prompt_alternatives_on'/1,
+        '$run_at_thread_start'/0,
+        '$system_catch'/4,
+        '$undefp'/1,
+		  '$version'/0]).
 
 :- use_system_module( '$_absf', ['$system_library_directories'/2]).
 
@@ -189,11 +212,11 @@ print_message(L,E) :-
 :- c_compile('directives.yap').
 :- c_compile('init.yap').
 
-'$sys':command(C,VL,Pos,Con) :-
+'$command'(C,VL,Pos,Con) :-
 	current_prolog_flag(strict_iso, true), !,      /* strict_iso on */
 	 '$yap_strip_module'(C, EM, EG),
    '$execute_command'(EG,EM,VL,Pos,Con,_Source).
-'$sys':command(C,VL,Pos,Con) :-
+'$command'(C,VL,Pos,Con) :-
 	( (Con = top ; var(C) ; C = [_|_])  ->
 	 '$yap_strip_module'(C, EM, EG),
 	  '$execute_command'(EG,EM,VL,Pos,Con,C) ;
diff --git a/pl/consult.yap b/pl/consult.yap
index b5a8f6364..5d0f57c65 100644
--- a/pl/consult.yap
+++ b/pl/consult.yap
@@ -40,7 +40,21 @@
         source_file/2,
         source_file_property/2,
         use_module/3],
-	['$initialization'/2]).
+	['$add_multifile'/3,
+        '$csult'/2,
+        '$do_startup_reconsult'/1,
+        '$elif'/2,
+        '$else'/1,
+        '$endif'/1,
+        '$if'/2,
+        '$include'/2,
+        '$initialization'/1,
+        '$initialization'/2,
+        '$lf_opt'/3,
+        '$load_files'/3,
+        '$require'/2,
+        '$set_encoding'/1,
+        '$use_module'/3]).
 
 :- use_system_module( '$_absf', ['$full_filename'/2]).
 
@@ -834,7 +848,7 @@ nb_setval('$if_le1vel',0).
 	erase(R),
 	G \= '$',
     strip_module(user:G, M0, G0),
-	( catch(M0:G0, Error, error_handler(Error, top))
+	( catch(M0:G0, Error, user:'$LoopError'(Error, top))
 	->
 	  true
 	;
@@ -851,7 +865,7 @@ nb_setval('$if_le1vel',0).
 '$process_init_goal'([G|_]) :-
 	'$yap_strip_module'( G, M0, G0),
 	(
-	 catch(M0:G0, Error, error_handler(Error, top))
+	 catch(M0:G0, Error, user:'$LoopError'(Error, top))
 	->
 	 true
 	;
@@ -915,7 +929,7 @@ nb_setval('$if_le1vel',0).
 	'$init_win_graphics',
 	fail.
 '$do_startup_reconsult'(X) :-
-    catch(load_files(user:X, [silent(true)]), Error, error_handler(Error, consult)),
+	catch(load_files(user:X, [silent(true)]), Error, '$LoopError'(Error, consult)),
 	!,
 	( current_prolog_flag(halt_after_consult, false) -> true ; halt).
 '$do_startup_reconsult'(_).
@@ -1455,24 +1469,7 @@ Similar to initialization/1, but allows for specifying when
 
 */
 initialization(G,OPT) :-
-    must_be_of_type(callable, G0, initialization(G0,OPT)),
-    must_be_of_type(oneof([after_load, now, restore]),
-                OPT, initialization(G0,OPT)),
-    '$yap_strip_module'(G0,M,G1),
-    '$expand_term'((M:G1), G),
-    (
-	OPT == now
-    ->
-    ( catch(G,E,error_handler(E)) -> true ; format(user_error,':- ~w failed.~n',[G]) )
-    ;
-    OPT == after_load
-    ->
-    '$initialization_queue'(G)
-    ;
-    OPT == restore
-    ->
-    recordz('$call_at_restore', G, _ )
-    ),
+   catch('$initialization'(G, OPT), Error, '$LoopError'( Error, consult ) ),
     fail.
 initialization(_G,_OPT).
 
@@ -1653,9 +1650,8 @@ End of conditional compilation.
 	nb_setval('$if_skip_mode',OldMode).
 
 
-'$if_call'(Goal) :-
-	'$expand_term'(Goal,TrueGoal),
-	catch(once(TrueGoal), E, (print_message(error, E), fail)).
+'$if_call'(G) :-
+	catch('$eval_if'(G), E, (print_message(error, E), fail)).
 
 '$eval_if'(Goal) :-
 	'$expand_term'(Goal,TrueGoal),
diff --git a/pl/control.yap b/pl/control.yap
index 14e5c78dd..ae0baa865 100644
--- a/pl/control.yap
+++ b/pl/control.yap
@@ -390,19 +390,19 @@ version(T) :-
 '$set_toplevel_hook'(_).
 
 query_to_answer(G, V, Status, Bindings) :-
-	gated_call( true, (G,'$sys':delayed_goals(G, V, Vs, LGs, _DCP)), Status, '$sys':answer( Status, LGs, Vs, Bindings) ).
+	gated_call( true, (G,'$delayed_goals'(G, V, Vs, LGs, _DCP)), Status, '$answer'( Status, LGs, Vs, Bindings) ).
 
-  '$sys':answer( exit, LGs, Vs, Bindings) :-
+  '$answer'( exit, LGs, Vs, Bindings) :-
       !,
       '$process_answer'(Vs, LGs, Bindings).
-      '$sys':answer( answer, LGs, Vs, Bindings) :-
+      '$answer'( answer, LGs, Vs, Bindings) :-
           !,
           '$process_answer'(Vs, LGs, Bindings).
-'$sys':answer(!, _, _, _).
-'$sys':answer(fail,_,_,_).
-'$sys':answer(exception(E),_,_,_) :-
+'$answer'(!, _, _, _).
+'$answer'(fail,_,_,_).
+'$answer'(exception(E),_,_,_) :-
         '$LoopError'(E,error).
-'$sys':answer(external_exception(_),_,_,_).
+'$answer'(external_exception(_),_,_,_).
 
 
 %% @}
@@ -471,13 +471,14 @@ b_getval(GlobalVariable, Val) :-
 	it saves the importante data about current streams and
 	debugger state */
 
-'$debug_state'(state(Trace, Debug, State, SPY_GN, GList)) :-
+'$debug_state'(state(Trace, Debug, State, SPY_GN, GList, GDList)) :-
 	'$init_debugger',
 	nb_getval('$trace',Trace),
 	nb_getval('$debug_state',State),
 	current_prolog_flag(debug, Debug),
 	nb_getval('$spy_gn',SPY_GN),
-	b_getval('$spy_glist',GList).
+	b_getval('$spy_glist',GList),
+	b_getval('$spy_depth',GDList).
 
 
 '$debug_stop' :-
@@ -485,15 +486,17 @@ b_getval(GlobalVariable, Val) :-
 	b_setval('$trace',off),
 	set_prolog_flag(debug, false),
 	b_setval('$spy_glist',[]),
-	b_setval('$spy_gdlist',[]).
+	b_setval('$spy_gdlist',[]),
+	'$disable_debugging'.
 
-
-'$debug_restart'(state(Trace, Debug, State, SPY_GN, GList)) :-
+'$debug_restart'(state(Trace, Debug, State, SPY_GN, GList, GDList)) :-
 	b_setval('$spy_glist',GList),
+	b_setval('$spy_gdlist',GDList),
 	b_setval('$spy_gn',SPY_GN),
 	set_prolog_flag(debug, Debug),
-	nb_setval('$debug_state',State),
-	b_setval('$trace',Trace).
+    nb_setval('$debug_state',State),
+	b_setval('$trace',Trace),
+	'$enable_debugging'.
 
 /** @pred  break
 
@@ -512,34 +515,20 @@ debugging.
 
 */
 break :-
-    '$e_setup_call_cleanup'(
-	prolog:'$enter_break'(Dstate,StdStreams,BL,NBL),
-	prolog:'$do_break'(NBL),
-	prolog:'$leave_break'(Dstate,StdStreams,BL)
-    ).	
-
-'$enter_break'(DState,streams(InpStream,OutStream,ErrStream),BL,NBL),
         '$debug_state'(DState),
+        '$debug_start',
 	'$break'( true ),
-	yap_flag( user_input, InpStream ),
-	yap_flag( user_output, OutStream ),
-	yap_flag( user_error, ErrStream ),
+	current_output(OutStream), current_input(InpStream),
 	current_prolog_flag(break_level, BL ),
         NBL is BL+1,
-	set_prolog_flag(break_level, NBL ).
-
-
-'$do_break'(NBL) :-
-    format(user_error, '% Break (level ~w)~n', [NBL]),
+	set_prolog_flag(break_level, NBL ),
+	format(user_error, '% Break (level ~w)~n', [NBL]),
 	'$do_live',
-	!.
-
-'$leave_break'(DState,streams(InpStream,OutStream,ErrStream),BL) :-
+	!,
 	set_value('$live','$true'),
         '$debug_restore'(DState),
-	yap_flag( user_input, InpStream ),
-	yap_flag( user_output, OutStream ),
-	yap_flag( user_error, ErrStream ),
+	set_input(InpStream),
+	set_output(OutStream),
 	set_prolog_flag(break_level, BL ),
 	'$break'( false ).
 
@@ -599,7 +588,7 @@ halt(X) :-
 '$run_atom_goal'(GA) :-
 	'$current_module'(Module),
 	atom_to_term(GA, G, _),
-	catch(once(Module:G), Error,error_handler(Error)).
+	catch(once(Module:G), Error,user:'$Error'(Error)).
 
 '$add_dot_to_atom_goal'([],[0'.]) :- !. %'
 '$add_dot_to_atom_goal'([0'.],[0'.]) :- !.
diff --git a/pl/debug.yap b/pl/debug.yap
index d371e1696..8a3f9e58c 100644
--- a/pl/debug.yap
+++ b/pl/debug.yap
@@ -307,17 +307,17 @@ be lost.
     '$$save_by'(CP),
     '$trace_query'(G, Mod, CP, G, EG),
     gated_call(
-	'$debugger':d_input,
+	'$debugger_input',
 	EG,
 	E,
-	'$debugger':d_continue(E)
+	'$continue_debugging'(E)
     ).
 
 
-'$debugger':d_continue(exit) :- !, '$creep'.
-'$debugger':d_continue(answer) :- !, '$creep'.
-'$debugger':d_continue(fail) :- !, '$creep'.
-'$debugger':d_continue(_).
+'$continue_debugging'(exit) :- !, '$creep'.
+'$continue_debugging'(answer) :- !, '$creep'.
+'$continue_debugging'(fail) :- !, '$creep'.
+'$continue_debugging'(_).
 
 
 
@@ -374,19 +374,19 @@ be lost.
   *   user_input is bound to a file.
   *
 */
-'$debugger':d_input :-
+'$debugger_input' :-
 	stream_property(_,alias(debugger_input)),
 	!.
-'$debugger':d_input :-
+'$debugger_input' :-
         S = user_input,
         stream_property(S,tty(true)),
     %    stream_property(S,input),
 	!,
 	set_stream(S,alias(debugger_input)).
-'$debugger':d_input :-
+'$debugger_input' :-
 	current_prolog_flag(unix, true ), !,
         open('/dev/tty', read, _S, [alias(debugger_input),bom(false)]).
-'$debugger':d_input :-
+'$debugger_input' :-
         current_prolog_flag(windows, true ), !,
         open('CONIN$', read, _S, [alias(debugger_input),bom(false)]).
 
@@ -469,10 +469,10 @@ be lost.
         '$debugger_expand_meta_call'(M:G, [], G1),
 	strip_module(G1, MF, NG),
 	gated_call(
-		   '$sys':enter_trace(GoalNumber, G, M, H),
-		   '$debugger':execute_nonstop(NG,MF),
+		   '$enter_trace'(GoalNumber, G, M, H),
+		   '$execute_nonstop'(NG,MF),
 		   Port,
-		   '$sys':trace_port(Port, GoalNumber, G, M, true, H)
+		   '$trace_port'(Port, GoalNumber, G, M, true, H)
                   ).
 % system_
 '$trace_goal'(G, M, GoalNumber, H) :-
@@ -483,24 +483,22 @@ be lost.
     ),
     !,
     gated_call(
-	'$sys':enter_trace(GoalNumber, G, M, H),
-	'$debugger':execute_nonstop(G,M),
+	'$enter_trace'(GoalNumber, G, M, H),
+	'$execute_nonstop'(G,M),
 	Port,
-	'$sys':trace_port(Port, GoalNumber, G, M, true, H)
+	'$trace_port'(Port, GoalNumber, G, M, true, H)
     ).
 '$trace_goal'(G, M, GoalNumber, H) :-
     gated_call(
-	'$sys':enter_trace(GoalNumber, G, M, H),
-	'$sys':debug( GoalNumber, G, M, H),
+	'$enter_trace'(GoalNumber, G, M, H),
+	'$debug'( GoalNumber, G, M, H),
 	Port,
-	'$sys':trace_port(Port, GoalNumber, G, M, true, H)
+	'$trace_port'(Port, GoalNumber, G, M, true, H)
     ).
 
-'$debugger':execute_nonstop(G,M) :-
-    '$execute_nonstop'(G,M).
 
 /**
- * @pred '$sys':enter_trace(+L, 0:G, +Module, +Info)
+ * @pred '$enter_trace'(+L, 0:G, +Module, +Info)
  *
  * call goal: prelims
  *
@@ -509,7 +507,7 @@ be lost.
  * @parameter _Info_ describes the goal
  *
  */
-'$sys':enter_trace(L, G, Module, Info) :-
+'$enter_trace'(L, G, Module, Info) :-
         /* get goal no.	*/
         ( var(L) ->
         '__NB_getval__'('$spy_gn',L,fail),
@@ -537,7 +535,7 @@ be lost.
         '__NB_setval__'('$spy_gn',L1).
 
 /**
- * @pred '$sys':enter_trace(+L, 0:G, +Module, +Info)
+ * @pred '$enter_trace'(+L, 0:G, +Module, +Info)
  *
  * call goal: setup the diferrent cases
  *  - zip, just run through
@@ -550,16 +548,16 @@ be lost.
  *
  */
 
-'$sys':debug(_, G, M, _H) :-
+'$debug'(_, G, M, _H) :-
     '__NB_getval__'('$debug_status',state(zip,_Border,Spy), fail),
     ( Spy == stop -> \+ '$pred_being_spied'(G,M) ; true ),
 	!,
 	'$execute_nonstop'( G, M ).
-'$sys':debug(GoalNumber, G, M, Info) :-
+'$debug'(GoalNumber, G, M, Info) :-
 	'$is_source'(G,M),
 	!,
 	'$trace_go'(GoalNumber, G, M, Info).
-'$sys':debug(GoalNumber, G, M, Info) :-
+'$debug'(GoalNumber, G, M, Info) :-
 	'$creep_step'(GoalNumber, G, M, Info).
 
 
@@ -600,7 +598,7 @@ be lost.
 '$retry_clause'(GoalNumber, G, Module, Info, _X) :-
     '$trace_port_'(redo, GoalNumber, G, Module, Info).
 
-'$sys':trace_port(Port, GoalNumber, G, Module, _CalledFromDebugger, Info) :-
+'$trace_port'(Port, GoalNumber, G, Module, _CalledFromDebugger, Info) :-
     '$stop_creeping'(_) ,
     current_prolog_flag(debug, true),
     '__NB_getval__'('$debug_status',state(Skip,Border,_), fail),
@@ -608,7 +606,7 @@ be lost.
     !,
     '__NB_setval__'('$debug_status', state(creep, 0, stop)),
     '$trace_port_'(Port, GoalNumber, G, Module, Info).
-'$sys':trace_port(_Port, _GoalNumber, _G, _Module, _CalledFromDebugger, _Info).
+'$trace_port'(_Port, _GoalNumber, _G, _Module, _CalledFromDebugger, _Info).
 
 '$trace_port_'(call, GoalNumber, G, Module, Info) :-
     '$port'(call,G,Module,GoalNumber,deterministic, Info).
@@ -782,7 +780,7 @@ be lost.
 	skip( debugger_input, 10),
 	break,
 	fail.
-'$action'('A',_,_,_,_,_) :- !,			% A		ancestors
+'$action'('A',_,_,_,_,_) :- !,			% 'b		break
 	skip( debugger_input, 10),
 	'$stack_dump',
 	fail.
diff --git a/pl/directives.yap b/pl/directives.yap
index 6efeb612e..38540758b 100644
--- a/pl/directives.yap
+++ b/pl/directives.yap
@@ -125,13 +125,11 @@
 
 
 '$exec_directive'(multifile(D), _, M, _, _) :-
-    catch(multifile(M:D),
+	'$system_catch'('$multifile'(D, M), M,
 	      Error,
-	      loop_Error(Error, top)).
+	      user:'$LoopError'(Error, top)).
 '$exec_directive'(discontiguous(D), _, M, _, _) :-
-    catch(discontiguous(M:D),
-	      Error,
-	      loop_Error(Error, top)).
+	'$discontiguous'(D,M).
 /** @pred initialization
 
 
diff --git a/pl/grammar.yap b/pl/grammar.yap
index 3e7c08718..63dd7ad93 100644
--- a/pl/grammar.yap
+++ b/pl/grammar.yap
@@ -94,10 +94,7 @@ Grammar related built-in predicates:
     Also, phrase/2-3 check their first argument.
 */
 
-prolog:'$translate_rule'(Rule, T) :-
-    translate_rule(Rule, T ).
-
-translate_rule(Rule, (NH :- B) ) :-
+prolog:'$translate_rule'(Rule, (NH :- B) ) :-
     source_module( SM ),
     '$yap_strip_module'( SM:Rule,  M0, (LP-->RP) ),
     t_head(LP, NH0, NGs, S, SR, (LP-->SM:RP)),
@@ -284,7 +281,7 @@ prolog:'\\+'(A, S0, S) :-
 
 '$c_built_in_phrase'(NT, Xs0, Xs, Mod, NewGoal) :-
 	nonvar(NT),
-    catch('$_grammar':translate_rule(
+    catch(prolog:'$translate_rule'(
           (pseudo_nt --> Mod:NT), Rule),
      	  error(Pat,ImplDep),
      	  ( \+ '$harmless_dcgexception'(Pat),
@@ -326,4 +323,3 @@ do_c_built_in(phrase(NT,Xs),Mod,_,NewGoal) :-
 /**
 @}
 */
-
diff --git a/pl/init.yap b/pl/init.yap
index 43aa8bfd6..330bc76c4 100644
--- a/pl/init.yap
+++ b/pl/init.yap
@@ -114,7 +114,7 @@
     fail.
 '$startup_goals' :-
     recorded('$startup_goal',G,_),
-    catch(once(user:G),Error,error_handler(Error)),
+    catch(once(user:G),Error,user:'$Error'(Error)),
     fail.
 '$startup_goals' :-
 	get_value('$init_goal',GA),
@@ -125,7 +125,7 @@
 '$startup_goals' :-
     recorded('$restore_flag', goal(Module:GA), R),
     erase(R),
-    catch(once(Module:GA),Error,error_handler(Error)),
+    catch(once(Module:GA),Error,user:'$Error'(Error)),
     fail.
 '$startup_goals' :-
 	get_value('$myddas_goal',GA), GA \= [],
@@ -204,7 +204,7 @@
 	recorded('$restore_goal',G,R),
 	erase(R),
 	prompt(_,'| '),
-	catch(once(user:G),Error,error_handler(Error)),
+	catch(once(user:G),Error,user:'$Error'(Error)),
 	fail.
 
 '$init_path_extensions' :-
diff --git a/pl/listing.yap b/pl/listing.yap
index a6ca3227a..753a38f27 100644
--- a/pl/listing.yap
+++ b/pl/listing.yap
@@ -318,6 +318,7 @@ portray_clause(Clause) :-
 
 '$beautify_vs'(T) :-
     '$non_singletons_in_term'(T,[],Fs),
+writeln(Fs),
     '$vv_transform'(Fs,1),
     term_variables(T, NFs),
     '$v_transform'(NFs).
diff --git a/pl/setof.yap b/pl/setof.yap
index 1225935dc..5ad05131c 100644
--- a/pl/setof.yap
+++ b/pl/setof.yap
@@ -292,7 +292,7 @@ Note that all/3 will fail if no answers are found.
 all(T, G same X,S) :- !, all(T same X,G,Sx), '$$produce'(Sx,S,X).
 all(T,G,S) :-
 	'$init_db_queue'(Ref),
-	( catch(G, Error,'$sys':clean_findall(Ref,Error) ),
+	( catch(G, Error,'$clean_findall'(Ref,Error) ),
 	  '$execute'(G),
 	  '$db_enqueue'(Ref, T),
 	  fail
diff --git a/pl/threads.yap b/pl/threads.yap
index 67a11e64b..5fe496375 100644
--- a/pl/threads.yap
+++ b/pl/threads.yap
@@ -132,11 +132,11 @@ volatile(P) :-
 	'$current_module'(Module),
 	'$run_at_thread_start',
 	% always finish with a throw to make sure we clean stacks.
-	catch((Module:G -> throw('$thread_finished'(true)) ; throw('$thread_finished'(false))),Exception,'$threads´:close_thread'(Exception,Detached)),
+	'$system_catch'((G -> throw('$thread_finished'(true)) ; throw('$thread_finished'(false))),Module,Exception,'$close_thread'(Exception,Detached)),
 	% force backtracking and handling exceptions
 	fail.
 
-'$threads´:close_thread'(Status, _Detached) :-
+'$close_thread'(Status, _Detached) :-
 	'$thread_zombie_self'(Id0), !,
 	'$record_thread_status'(Id0,Status),
 	'$run_at_thread_exit'(Id0),
diff --git a/pl/top.yap b/pl/top.yap
index 81a6fc1be..becde72e6 100644
--- a/pl/top.yap
+++ b/pl/top.yap
@@ -30,7 +30,7 @@ live :-
     ;
     format(user_error,'[~w]~n', [Module])
     ),
-    '$enter_top_level'.
+    '$system_catch'('$enter_top_level',Module,Error,'$Error'(Error)).
 
 % Start file for yap
 
@@ -46,9 +46,18 @@ live :-
 /* main execution loop							*/
 '$read_toplevel'(Goal, Bindings, Pos) :-
 	'$prompt',
-	read_term(user_input,
+	catch(read_term(user_input,
 			Goal,
-			[variable_names(Bindings), syntax_errors(dec10), term_position(Pos)]).
+			[variable_names(Bindings), syntax_errors(dec10), term_position(Pos)]),
+			 E, '$handle_toplevel_error'( E) ).
+
+'$handle_toplevel_error'( syntax_error(_)) :-
+	!,
+	fail.
+'$handle_toplevel_error'( error(io_error(read,user_input),_)) :-
+	!.
+'$handle_toplevel_error'(_, E) :-
+	throw(E).
 
 
 /** @pred  stream_property( Stream, Prop )
@@ -76,7 +85,7 @@ live :-
 				% stop at spy-points if debugging is on.
 	nb_setval('$debug_run',off),
 	nb_setval('$debug_jump',off),
-	catch('$sys':command(Command,Varnames,Pos,top),E,error_handler(E)),
+	'$command'(Command,Varnames,Pos,top),
 	current_prolog_flag(break_level, BreakLevel),
 	(
 	 BreakLevel \= 0
@@ -116,7 +125,7 @@ live :-
 '$execute_commands'([C|Cs],M,VL,Pos,Con,Source) :-
     !,
     (
-	'$execute_command'(C,M,VL,Pos,Con,Source),
+	'$system_catch'('$execute_command'(C,M,VL,Pos,Con,Source),prolog,Error,'$LoopError'(Error, Con)),
 	fail
     ;
     '$execute_commands'(Cs,M,VL,Pos,Con,Source)
@@ -131,20 +140,20 @@ live :-
 '$execute_command'(C,_,_,_,_,Source) :-
     var(C),
     !,
-    '$do_error'(instantiation_error,meta_call(Source)).
+	'$do_error'(instantiation_error,meta_call(Source)).
 '$execute_command'(C,_,_,_,_top,Source) :-
     number(C),
     !,
-    '$do_error'(type_error(callable,C),meta_call(Source)).
+	'$do_error'(type_error(callable,C),meta_call(Source)).
  '$execute_command'(R,_,_,_,_top,Source) :-
      db_reference(R),
      !,
-     '$do_error'(type_error(callable,R),meta_call(Source)).
+	 '$do_error'(type_error(callable,R),meta_call(Source)).
  '$execute_command'(end_of_file,_,_,_,_,_) :- !.
  '$execute_command'(Command,_,_,_,_,_) :-
-     '__NB_getval__'('$if_skip_mode', skip, fail),
-     \+ '$if_directive'(Command),
-     !.
+	 '__NB_getval__'('$if_skip_mode', skip, fail),
+	 \+ '$if_directive'(Command),
+	 !.
 '$execute_command'((:-G),M,VL,Pos,Option,_) :-
     Option \= top,
     !,			% allow user expansion
@@ -153,29 +162,29 @@ live :-
     (
             NO = (:- G1)
         ->
-	'$process_directive'(G1, Option, NM, VL, Pos)
+	      '$process_directive'(G1, Option, NM, VL, Pos)
      ;
-     '$execute_commands'(G1,NM,VL,Pos,Option,O)
-    ).
+           '$execute_commands'(G1,NM,VL,Pos,Option,O)
+        ).
 '$execute_command'((?-G), M, VL, Pos, Option, Source) :-
-    Option \= top,
-    !,
-    '$execute_command'(G, M, VL, Pos, top, Source).
+	 Option \= top,
+	 !,
+	 '$execute_command'(G, M, VL, Pos, top, Source).
  '$execute_command'(G, M, VL, Pos, Option, Source) :-
-     '$continue_with_command'(Option, VL, Pos, M:G, Source).
+	 '$continue_with_command'(Option, VL, Pos, M:G, Source).
 
 '$expand_term'(T,O) :-
-    '$expand_term'(T,top,O).
+	 '$expand_term'(T,top,O).
 
 '$expand_term'(T,Con,O) :-
-	 '$expand_term0'(T,Con,O),
+	catch( '$expand_term0'(T,Con,O), _,( '$disable_debugging', fail) ),
       	!.
 
-'$expand_term0'(T,consult,O) :-
-    expand_term( T,  O).
-'$expand_term0'(T,reconsult,O) :-
-    expand_term( T,  O).
-'$expand_term0'(T,top,O) :-
+		'$expand_term0'(T,consult,O) :-
+		expand_term( T,  O).
+		'$expand_term0'(T,reconsult,O) :-
+		expand_term( T,  O).
+		'$expand_term0'(T,top,O) :-
 	expand_term( T,  T1),
 	!,
  	'$expand_term1'(T1,O).
@@ -188,16 +197,16 @@ live :-
 
 '$continue_with_command'(Where,V,'$stream_position'(C,_P,A1,A2,A3),'$source_location'(_F,L):G,Source) :-
     !,
-    '$continue_with_command'(Where,V,'$stream_position'(C,L,A1,A2,A3),G,Source).
+	'$continue_with_command'(Where,V,'$stream_position'(C,L,A1,A2,A3),G,Source).
 '$continue_with_command'(reconsult,V,Pos,G,Source) :-
 %    writeln(G),
-    '$go_compile_clause'(G,V,Pos,reconsult,Source),
-    fail.
+	'$go_compile_clause'(G,V,Pos,reconsult,Source),
+	fail.
 '$continue_with_command'(consult,V,Pos,G,Source) :-
-    '$go_compile_clause'(G,V,Pos,consult,Source),
-    fail.
+	'$go_compile_clause'(G,V,Pos,consult,Source),
+	fail.
 '$continue_with_command'(top,V,_,G,_) :-
-    '$query'(G,V).
+	'$query'(G,V).
 
  %%
  % @pred '$go_compile_clause'(G,Vs,Pos, Where, Source) is det
@@ -282,31 +291,31 @@ live :-
 	 '$yes_no'(G,(?-)).
 '$query'(G,V) :-
 	 (
-	     '$current_module'(M),
-	     '$current_choice_point'(CP),
-	     '$user_call'(G, M),
-	     '$current_choice_point'(NCP),
-	     '$sys':delayed_goals(G, V, Vs, LGs, DCP),
-	     '$write_answer'(Vs, LGs, Written),
-	     '$write_query_answer_true'(Written),
-	     (
-		 '$prompt_alternatives_on'(determinism), CP == NCP, DCP = 0
-	     ->
-	     format(user_error, '.~n', []),
-	     !
-	     ;
-	     '$another',
-	     !
-	     ),
-	     fail
+     '$current_module'(M),
+     '$current_choice_point'(CP),
+     '$user_call'(G, M),
+     '$current_choice_point'(NCP),
+     '$delayed_goals'(G, V, Vs, LGs, DCP),
+     '$write_answer'(Vs, LGs, Written),
+	  '$write_query_answer_true'(Written),
+	  (
+	   '$prompt_alternatives_on'(determinism), CP == NCP, DCP = 0
+	   ->
+	   format(user_error, '.~n', []),
+	   !
+	  ;
+	   '$another',
+	   !
+	  ),
+	  fail
 	 ;
-	 '$out_neg_answer'
+	  '$out_neg_answer'
 	 ).
 
-'$yes_no'(G,C):-
+ '$yes_no'(G,C) :-
 	 '$current_module'(M),
 	 '$do_yes_no'(G,M),
-	 '$sys':delayed_goals(G, [], NV, LGs, _),
+	 '$delayed_goals'(G, [], NV, LGs, _),
 	 '$write_answer'(NV, LGs, Written),
 	 ( Written = [] ->
 	   !,'$present_answer'(C, true)
@@ -321,15 +330,15 @@ live :-
 
 
 '$process_answer'(Vs, LGs, Bindings) :-
-    '$purge_dontcares'(Vs,IVs),
-    '$sort'(IVs, NVs),
-    '$prep_answer_var_by_var'(NVs, LAnsw, LGs),
-    '$name_vars_in_goals'(LAnsw, Vs, Bindings).
+'$purge_dontcares'(Vs,IVs),
+'$sort'(IVs, NVs),
+'$prep_answer_var_by_var'(NVs, LAnsw, LGs),
+'$name_vars_in_goals'(LAnsw, Vs, Bindings).
 
 %
 % *-> at this point would require compiler support, which does not exist.
 %
-'$sys':delayed_goals(G, V, NV, LGs, NCP) :-
+'$delayed_goals'(G, V, NV, LGs, NCP) :-
 	(
 	 '$$save_by'(NCP1),
 	 attributes:delayed_goals(G, V, NV, LGs),
@@ -634,11 +643,10 @@ write_query_answer( Bindings ) :-
 
 '$call'(M:_,_,G0,_) :- var(M), !,
 	'$do_error'(instantiation_error,call(G0)).
-/*'$call'(M:G,CP,G0,_M0) :- !,
+'$call'(M:G,CP,G0,_M0) :- !,
 '$expand_meta_call'(M:G, [], NG),
 '$yap_strip_module'(NG,NM,NC),
         '$call'(NC,CP,G0,NM).
-*/
 '$call'((X,Y),CP,G0,M) :- !,
         '$call'(X,CP,G0,M),
         '$call'(Y,CP,G0,M).
@@ -740,7 +748,8 @@ write_query_answer( Bindings ) :-
     prompt1(': '), prompt(_,'     '),
 	'$current_module'(OldModule),
 	repeat,
-	dbload_from_stream(Stream, OldModule, exo),
+		'$system_catch'(dbload_from_stream(Stream, OldModule, exo), '$db_load', Error,
+			 user:'$LoopError'(Error, top)),
 	prolog_flag(agc_margin,_,Old),
 	!.
 '$loop'(Stream,db) :-
@@ -748,13 +757,17 @@ write_query_answer( Bindings ) :-
     prompt1(': '), prompt(_,'     '),
 	'$current_module'(OldModule),
 	repeat,
-	dbload_from_stream(Stream, OldModule, db),
+		'$system_catch'(dbload_from_stream(Stream, OldModule, db), '$db_load', Error,
+			 user:'$LoopError'(Error, top)),
 	prolog_flag(agc_margin,_,Old),
 	!.
 '$loop'(Stream,Status) :-
  	repeat,
-	'$current_module'( OldModule, OldModule ),
-	 '$enter_command'(Stream,OldModule,Status),
+  '$current_module'( OldModule, OldModule ),
+	'$system_catch'( '$enter_command'(Stream,OldModule,Status),
+                     OldModule, Error,
+			         user:'$LoopError'(Error, Status)
+                   ),
 	!.
 
 '$boot_loop'(Stream,Where) :-
@@ -762,19 +775,22 @@ write_query_answer( Bindings ) :-
 	'$current_module'( OldModule, OldModule ),
 	read_clause(Stream, Command, [module(OldModule), syntax_errors(dec10),variable_names(_Vars), term_position(_Pos)]),
 	(Command == end_of_file
-	->
-	    !
+  ->
+    !
 	;
-	Command = (:- Goal) ->
-	'$boot_execute'(Goal),
-	fail
-	;
-	Command = (H --> B) ->
-     '$boot_dcg'(H,B, Where),
+   Command = (:- Goal) ->
+     '$system_catch'('$boot_execute'(Goal),   prolog, Error,
+        user:'$LoopError'(Error, consult) ),
+    fail
+   ;
+Command = (H --> B) ->
+     '$system_catch'('$boot_dcg'(H,B, Where),   prolog, Error,
+        user:'$LoopError'(Error, consult) ),
 
   fail
  ;
-     '$boot_clause'( Command, Where ),
+     '$system_catch'('$boot_clause'( Command, Where ),  prolog, Error,
+        user:'$LoopError'(Error, consult) ),
   fail
  ).
 
@@ -800,9 +816,8 @@ write_query_answer( Bindings ) :-
 
 
 '$enter_command'(Stream, Mod, Status) :-
-    prompt1(': '),
-    prompt(_,'     '),
-    Options = [module(Mod), syntax_errors(dec10),variable_names(Vars), term_position(Pos)],
+    prompt1(': '), prompt(_,'     '),
+	Options = [module(Mod), syntax_errors(dec10),variable_names(Vars), term_position(Pos)],
     (
       Status == top
     ->
@@ -810,7 +825,7 @@ write_query_answer( Bindings ) :-
     ;
       read_clause(Stream, Command, Options)
     ),
-    catch('$sys':command(Command,Vars,Pos, Status), Error, error_handler(Error,top)).
+	'$command'(Command,Vars,Pos, Status).
 
 /** @pred  user:expand_term( _T_,- _X_) is dynamic,multifile.
 
@@ -909,7 +924,7 @@ expand_term(Term,Expanded) :-
 % Grammar Rules expansion
 %
 '$expand_term_grammar'((A-->B), C) :-
-	'$translate_rule'((A-->B),C), !.
+	prolog:'$translate_rule'((A-->B),C), !.
 '$expand_term_grammar'(A, A).
 
 %
@@ -1020,8 +1035,7 @@ a matching catch/3, or until reaching top-level.
 	current_prolog_flag(break_level, 0 ),
 	recorded('$toplevel_hooks',H,_),
 	H \= fail, !,
-	ignore(user:H),
-	fail.
+	( call(user:H) -> true ; true).
 '$run_toplevel_hooks'.
 
 '$run_at_thread_start' :-
diff --git a/pl/yio.yap b/pl/yio.yap
index 4bbc7a708..785e6b8de 100644
--- a/pl/yio.yap
+++ b/pl/yio.yap
@@ -181,7 +181,7 @@ display(Stream, T) :-
 /* interface to user portray	*/
 '$portray'(T) :-
 	\+ '$undefined'(portray(_),user),
-	catch(user:portray(T),Error,error_handler(Error)), !,
+	catch(user:portray(T),Error,user:'$Error'(Error)), !,
 	set_value('$portray',true), fail.
 '$portray'(_) :- set_value('$portray',false), fail.