diff --git a/pl/CMakeFiles/progress.marks b/pl/CMakeFiles/progress.marks
index 21e72e8ac..0691f67b2 100644
--- a/pl/CMakeFiles/progress.marks
+++ b/pl/CMakeFiles/progress.marks
@@ -1 +1 @@
-48
+52
diff --git a/pl/arith.yap b/pl/arith.yap
index bd9323168..cac89fa61 100644
--- a/pl/arith.yap
+++ b/pl/arith.yap
@@ -112,7 +112,7 @@ q(A):-
       A is 22.
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-*/
+w*/
 do_not_compile_expressions :- set_value('$c_arith',[]).
 
 '$c_built_in'(IN, M, H, OUT) :-
@@ -128,14 +128,12 @@ do_c_built_in(Mod:G, _, H, OUT) :-
 	var(G1), !,
 	do_c_built_metacall(G1, M1, H, OUT).
 do_c_built_in('C'(A,B,C), _, _, (A=[B|C])) :- !.
-do_c_built_in('$do_error'( Error, Goal), M, H,
-	      ('$p_and_cp'(Goal, Caller),
-	       functor(H,Na,Ar),
-	       throw(error(Error, [g=Goal,c=c(M:Na/Ar,File,FilePos),p=Caller]))
+do_c_built_in('$do_error'( Error, Goal), M, Head,
+	      (clause_location(Call, Caller),
+	       strip_module(M:Goal,M1,NGoal),
+	       throw(error(Error, [[g|g(M1:NGoal)],[p|Call],[e|Caller],[h|g(Head)]]))
 	      )
-	     ):-
-        stream_property( loop_stream, name(File) ),
-        stream_property( loop_stream, position(FilePos) ).
+	     ) :- !.
 do_c_built_in(X is Y, M, H,  P) :-
         primitive(X), !,
 	do_c_built_in(X =:= Y, M, H, P).
@@ -157,7 +155,7 @@ do_c_built_in(phrase(NT,Xs0,Xs), Mod, _,  NewGoal) :-
     '$goal_expansion_allowed'(phrase(NT,Xs0,Xs), Mod),
     Goal = phrase(NT,Xs0,Xs),
     callable(NT),
-    catch('$translate_rule'((pseudo_nt --> NT), Rule),
+    catch(prolog:'$translate_rule'((pseudo_nt --> NT), Rule),
 	  error(Pat,ImplDep),
 	  ( \+ '$harmless_dcgexception'(Pat),
 	    throw(error(Pat,ImplDep))
@@ -374,7 +372,7 @@ expand_expr(Op, X, Y, O, Q, P) :-
 '$harmless_dcgexception'(type_error(callable,_)).	% ex: phrase(27,L)
 
 
-
+:- set_value('$c_arith',true).
 /**
   @}
 */
diff --git a/pl/boot.yap b/pl/boot.yap
index ae81404f9..cd610c1c6 100644
--- a/pl/boot.yap
+++ b/pl/boot.yap
@@ -186,6 +186,7 @@ list, since backtracking could not "pass through" the cut.
 */
 
 
+
 system_module(_init, _SysExps, _Decls) :- !.
 system_module(M, SysExps, Decls) :-
 	'$current_module'(prolog, M),
@@ -286,6 +287,49 @@ private(_).
 :- use_system_module( '$_strict_iso', ['$check_iso_strict_clause'/1,
         '$iso_check_goal'/2]).
 
+'$prepare_goals'((A,B),(NA,NB),Any) :-
+	!,
+	'$prepare_goals'(A,NA,Any),
+	'$prepare_goals'(B,NB,Any).
+'$prepare_goals'((A;B),(NA;NB),Any) :-
+	!,
+	'$prepare_goals'(A,NA,Any),
+	'$prepare_goals'(B,NB,Any).
+'$prepare_goals'((A->B),(NA->NB),Any) :-
+	!,
+	'$prepare_goals'(A,NA,Any),
+	'$prepare_goals'(B,NB,Any).
+'$prepare_goals'((A*->B),(NA*->NB),Any) :-
+	!,
+	'$prepare_goals'(A,NA,Any),
+	'$prepare_goals'(B,NB,Any).
+'$prepare_goals'((\+ A),(\+ NA),Any) :-
+	!,
+	'$prepare_goals'(A,NA,Any).
+'$prepare_goals'('$do_error'(Error,Goal),
+               (clause_location(Call, Caller),
+		writeln(Goal),
+		strip_module(M:Goal,M1,NGoal),
+		throw(error(Error, [[g|g(M1:NGoal)],[p|Call],[e|Caller],[h|g(Head)]]))
+	       ),
+               true) :-
+	!.
+'$prepare_goals'(X is AOB,
+                 is(X, IOp, A, B ),
+		 true) :-
+	var(X),
+	functor(AOB, Op, 2),
+	arg(1, AOB, A),
+	arg(2, AOB, B),
+	!,
+	'$binary_op_as_integer'(Op,IOp).
+'$prepare_goals'((A,B),(A,B),_Any).
+
+'$prepare_clause'((H :- B), (H:-NB)) :-
+	'$prepare_goals'(B,NB,Any),
+	Any==true.
+
+
 
 %
 %
@@ -1326,6 +1370,7 @@ bootstrap(F) :-
 	'$start_consult'(consult, File, LC),
 	file_directory_name(File, Dir),
 	working_directory(OldD, Dir),
+
 	(
 	  current_prolog_flag(verbose_load, silent)
 	->
@@ -1452,7 +1497,7 @@ expand_term(Term,Expanded) :-
 % Grammar Rules expansion
 %
 '$expand_term_grammar'((A-->B), C) :-
-	'$translate_rule'((A-->B),C), !.
+	prolog:'$translate_rule'((A-->B),C), !.
 '$expand_term_grammar'(A, A).
 
 %
diff --git a/pl/consult.yap b/pl/consult.yap
index 73a33cf59..97faf5897 100644
--- a/pl/consult.yap
+++ b/pl/consult.yap
@@ -431,8 +431,8 @@ load_files(Files,Opts) :-
     b_setval('$source_file', File),
     ( var(Stream) ->
 	  /* need_to_open_file */
-	  '$full_filename'(File, Y, Call),
-	  open(Y, read, Stream)
+	  ( '$full_filename'(File, Y, Call) -> true ; '$do_error'(existence_error(source_sink,File),Call) ),
+	  ( open(Y, read, Stream) -> true ; '$do_error'(permission_error(input,stream,Y),Call) )
         ;
 	stream_property(Stream, file_name(Y))
     ), !,
@@ -446,8 +446,7 @@ load_files(Files,Opts) :-
     '$start_lf'(If, Mod, Stream, TOpts, File, Y, Reexport, Imports),
 %	stop_low_level_trace,
     close(Stream).
-'$lf'(X, _, Call, _) :-
-    '$do_error'(permission_error(input,stream,X),Call).
+
 
 '$start_lf'(not_loaded, Mod, _Stream, TOpts, UserFile, File, Reexport,Imports) :-
 	'$file_loaded'(File, Mod, Imports, TOpts), !,
diff --git a/pl/grammar.yap b/pl/grammar.yap
index eac07275d..e692c2deb 100644
--- a/pl/grammar.yap
+++ b/pl/grammar.yap
@@ -78,7 +78,7 @@ Grammar related built-in predicates:
 :- use_system_module( '$_errors', ['$do_error'/2]).
 
 % :- meta_predicate ^(?,0,?).
-% ^(Xs, Goal, Xs) :- call(Goal).
+				% ^(Xs, Goal, Xs) :- call(Goal).
 
 % :- meta_predicate ^(?,1,?,?).
 % ^(Xs0, Goal, Xs0, Xs) :- call(Goal, Xs).
diff --git a/pl/init.yap b/pl/init.yap
index 33ca7edf6..8e0bbb0c4 100644
--- a/pl/init.yap
+++ b/pl/init.yap
@@ -119,7 +119,7 @@ print_message(_, loaded(F,C,_M,T,H)) :- !,
 print_message(_, Msg) :-
 	format(user_error, '~w ~n', [Msg]).
 
-:- bootstrap('errors.yap').
+:- bootstrap(   'arith.yap').
 :- bootstrap('lists.yap').
 :- bootstrap('consult.yap').
 :- bootstrap('preddecls.yap').
@@ -129,14 +129,14 @@ print_message(_, Msg) :-
 :- bootstrap('atoms.yap').
 :- bootstrap('os.yap').
 :- bootstrap('absf.yap').
-xs%:- start_low_level_trace.
+%:- Start_low_level_trace.
 :-set_prolog_flag(verbose,  normal).
 
 :-set_prolog_flag(gc_trace, verbose).
 %:- set_prolog_flag( verbose_file_search, true ).
 
 :- [
-    'arith.yap',
+    'errors.yap',
     'directives.yap',
     'utils.yap',
     'control.yap',