diff --git a/C/atoms.c b/C/atoms.c
index 24732d688..fd4d71b93 100644
--- a/C/atoms.c
+++ b/C/atoms.c
@@ -30,6 +30,7 @@ static char     SccsId[] = "%W% %G%";
 #include "YapHeap.h"
 #include "eval.h"
 #include "yapio.h"
+#include "pl-shared.h"
 #ifdef TABLING
 #include "tab.macros.h"
 #endif /* TABLING */
@@ -656,8 +657,9 @@ p_atom_chars( USES_REGS1 )
       return(FALSE);		
     }
     {
+      LD_FROM_REGS
       /* ISO Prolog Mode */
-      int has_atoms = yap_flags[STRICT_ISO_FLAG];
+      int has_atoms = truePrologFlag(PLFLAG_ISO);
       int has_ints =  FALSE;
 
       while (t != TermNil) {
@@ -1308,7 +1310,8 @@ p_atom_length( USES_REGS1 )
     }
     return Yap_unify(ARG2, MkIntegerTerm(len));
   } else if (!IsAtomTerm(t1)) {
-    if (!yap_flags[STRICT_ISO_FLAG]) {
+    LD_FROM_REGS
+    if (!truePrologFlag(PLFLAG_ISO)) {
       char *String; 
 
       if (IsIntegerTerm(t1)) {
@@ -1547,7 +1550,8 @@ p_number_chars( USES_REGS1 )
   s = String;
   {
     /* ISO code */
-    int has_atoms = yap_flags[STRICT_ISO_FLAG];
+    LD_FROM_REGS
+    int has_atoms = truePrologFlag(PLFLAG_ISO);
     int has_ints =  FALSE;
 
     while (t != TermNil) {
diff --git a/C/init.c b/C/init.c
index fa9cc0df2..961668846 100755
--- a/C/init.c
+++ b/C/init.c
@@ -169,7 +169,8 @@ OpDec(int p, char *type, Atom a, Term m)
     WRITE_UNLOCK(ae->ARWLock);
   }
   if (i <= 3) {
-    if (yap_flags[STRICT_ISO_FLAG] && 
+    GET_LD
+    if (truePrologFlag(PLFLAG_ISO) && 
 	info->Posfix != 0) /* there is a posfix operator */ {
       /* ISO dictates */
       WRITE_UNLOCK(info->OpRWLock);
@@ -178,7 +179,8 @@ OpDec(int p, char *type, Atom a, Term m)
     }
     info->Infix = p;
   } else if (i <= 5) {
-    if (yap_flags[STRICT_ISO_FLAG] && 
+    GET_LD
+    if (truePrologFlag(PLFLAG_ISO) && 
 	info->Infix != 0) /* there is an infix operator */ {
       /* ISO dictates */
       WRITE_UNLOCK(info->OpRWLock);
@@ -902,7 +904,6 @@ InitFlags(void)
   /* note that Yap_heap_regs must be set first */
 
   yap_flags[LANGUAGE_MODE_FLAG] = 0;
-  yap_flags[STRICT_ISO_FLAG] = FALSE;
   yap_flags[SOURCE_MODE_FLAG] = FALSE;
   yap_flags[WRITE_QUOTED_STRING_FLAG] = FALSE;
   /* we do not garantee safe assert in parallel mode */
@@ -995,8 +996,6 @@ InitLogDBErasedMarker(void)
   INIT_CLREF_COUNT(Yap_heap_regs->logdb_erased_marker);
 }
 
-#define SWIAtomToAtom(X) SWI_Atoms[(X)>>1]
-
 static void 
 InitSWIAtoms(void)
 {
diff --git a/C/pl-yap.c b/C/pl-yap.c
index cb4d2cecb..f2dffaac9 100755
--- a/C/pl-yap.c
+++ b/C/pl-yap.c
@@ -1034,6 +1034,28 @@ PL_dispatch(int fd, int wait)
   return TRUE;
 }
 
+/* SWI: int PL_get_arg(int index, term_t t, term_t a)
+   YAP: YAP_Term YAP_ArgOfTerm(int argno, YAP_Term t)*/
+X_API int _PL_get_arg__LD(int index, term_t ts, term_t a ARG_LD)
+{
+  REGS_FROM_LD
+  YAP_Term t = Yap_GetFromSlot(ts PASS_REGS);
+  if ( !YAP_IsApplTerm(t) ) {
+    if (YAP_IsPairTerm(t)) {
+      if (index == 1){
+	Yap_PutInSlot(a,HeadOfTerm(t) PASS_REGS);
+	return 1;
+      } else if (index == 2) {
+	Yap_PutInSlot(a,TailOfTerm(t) PASS_REGS);
+	return 1;
+      }
+    }
+    return 0;
+  }
+  Yap_PutInSlot(a,ArgOfTerm(index, t) PASS_REGS);
+  return 1;
+}
+   
 /* SWI: int PL_get_atom(term_t t, YAP_Atom *a)
    YAP: YAP_Atom YAP_AtomOfTerm(Term) */
 int PL_get_atom__LD(term_t ts, atom_t *a ARG_LD)
@@ -1046,6 +1068,13 @@ int PL_get_atom__LD(term_t ts, atom_t *a ARG_LD)
   return 1;
 }
 
+X_API int PL_put_atom__LD(term_t t, atom_t a ARG_LD)
+{
+  REGS_FROM_LD
+  Yap_PutInSlot(t,MkAtomTerm(SWIAtomToAtom(a)) PASS_REGS);
+  return TRUE;
+}
+
 void PL_put_term__LD(term_t d, term_t s ARG_LD)
 {
   REGS_FROM_LD
diff --git a/C/scanner.c b/C/scanner.c
index dac2ea073..7bb9687d0 100644
--- a/C/scanner.c
+++ b/C/scanner.c
@@ -232,12 +232,11 @@ extern double atof(const char *);
 static Term
 float_send(char *s, int sign)
 {
-  CACHE_REGS
+  GET_LD
   Float f = (Float)atof(s);
 #if HAVE_FINITE
-  if (yap_flags[LANGUAGE_MODE_FLAG] == 1) { /* iso */
+  if (truePrologFlag(PLFLAG_ISO)) { /* iso */
     if (!finite(f)) {
-      CACHE_REGS
       LOCAL_ErrorMessage = "Float overflow while scanning";
       return(MkEvalFl(0.0));
     }
@@ -279,6 +278,7 @@ send_error_message(char s[])
 static wchar_t
 read_quoted_char(int *scan_nextp, IOSTREAM *inp_stream)
 {
+  GET_LD
   int ch;
 
   /* escape sequence */
@@ -359,7 +359,7 @@ read_quoted_char(int *scan_nextp, IOSTREAM *inp_stream)
   case '`':
     return '`';
   case '^':
-    if (FALSE /*yap_flags[CHARACTER_ESCAPE_FLAG] == ISO_CHARACTER_ESCAPES */) {
+    if (truePrologFlag(PLFLAG_ISO)) {
       return send_error_message("invalid escape sequence");
     } else {
       ch = getchrq(inp_stream);
@@ -458,7 +458,7 @@ num_send_error_message(char s[])
 static Term
 get_num(int *chp, int *chbuffp, IOSTREAM *inp_stream, char *s, UInt max_size, int sign)
 {
-  CACHE_REGS
+  GET_LD
   char *sp = s;
   int ch = *chp;
   Int val = 0L, base = ch - '0';
@@ -574,7 +574,7 @@ get_num(int *chp, int *chbuffp, IOSTREAM *inp_stream, char *s, UInt max_size, in
     ch = getchr(inp_stream);
   }
   if (might_be_float && ( ch == '.'  || ch == 'e' || ch == 'E')) {
-    if (yap_flags[STRICT_ISO_FLAG] && (ch == 'e' || ch == 'E')) {
+    if (truePrologFlag(PLFLAG_ISO) && (ch == 'e' || ch == 'E')) {
       return num_send_error_message("Float format not allowed in ISO mode");
     }
     if (ch == '.') {
@@ -796,7 +796,7 @@ ch_to_wide(char *base, char *charp)
 TokEntry *
 Yap_tokenizer(IOSTREAM *inp_stream, int store_comments, Term *tposp)
 {
-  CACHE_REGS
+  GET_LD
   TokEntry *t, *l, *p;
   enum TokenKinds kind;
   int solo_flag = TRUE;
@@ -1076,7 +1076,7 @@ Yap_tokenizer(IOSTREAM *inp_stream, int store_comments, Term *tposp)
 	  LOCAL_ErrorMessage = "Heap Overflow While Scanning: please increase code space (-h)";
 	  break;
 	}
-	if (ch == 10  &&  FALSE /*yap_flags[CHARACTER_ESCAPE_FLAG] == ISO_CHARACTER_ESCAPES */) {
+	if (ch == 10  &&  truePrologFlag(PLFLAG_ISO)) {
 	  /* in ISO a new line terminates a string */
 	  LOCAL_ErrorMessage = "layout character \n inside quotes";
 	  break;
diff --git a/C/stdpreds.c b/C/stdpreds.c
index 392e70dba..b9fbe30ac 100644
--- a/C/stdpreds.c
+++ b/C/stdpreds.c
@@ -273,6 +273,7 @@ static char     SccsId[] = "%W% %G%";
 #include "YapHeap.h"
 #include "eval.h"
 #include "yapio.h"
+#include "pl-shared.h"
 #ifdef TABLING
 #include "tab.macros.h"
 #endif /* TABLING */
@@ -330,6 +331,7 @@ static Int p_runtime( USES_REGS1 );
 static Int p_walltime( USES_REGS1 );
 static Int p_access_yap_flags( USES_REGS1 );
 static Int p_set_yap_flags( USES_REGS1 );
+static Int p_break( USES_REGS1 );
 
 #ifdef BEAM
 Int use_eam( USES_REGS1 );
@@ -1659,11 +1661,6 @@ p_set_yap_flags( USES_REGS1 )
     }
     yap_flags[LANGUAGE_MODE_FLAG] = value;
     break;
-  case STRICT_ISO_FLAG:
-    if (value != 0 && value !=  1)
-      return(FALSE);
-    yap_flags[STRICT_ISO_FLAG] = value;
-    break;
   case SOURCE_MODE_FLAG:
     if (value != 0 && value !=  1)
       return(FALSE);
@@ -1837,13 +1834,17 @@ p_loop( USES_REGS1 ) {
 
 
 static Int
-p_max_tagged_integer( USES_REGS1 ) {
-  return Yap_unify(ARG1, MkIntTerm(MAX_ABS_INT-((CELL)1)));
-}
-
-static Int
-p_min_tagged_integer( USES_REGS1 ) {
-  return Yap_unify(ARG1, MkIntTerm(-MAX_ABS_INT));
+p_break( USES_REGS1 ) {
+  Atom at = AtomOfTerm(Deref( ARG1 ));
+  if (at == AtomTrue) {
+    LOCAL_PL_local_data_p->break_level++;
+    return TRUE;
+  }
+  if (at == AtomFalse) {
+    LOCAL_PL_local_data_p->break_level--;
+    return TRUE;
+  }
+  return FALSE;
 }
 
 void 
@@ -1922,8 +1923,7 @@ Yap_InitCPreds(void)
   Yap_InitCPred("$set_yap_flags", 2, p_set_yap_flags, SafePredFlag|SyncPredFlag);
   Yap_InitCPred("$p_system_mode", 1, p_system_mode, SafePredFlag|SyncPredFlag);
   Yap_InitCPred("abort", 0, p_abort, SyncPredFlag);
-  Yap_InitCPred("$max_tagged_integer", 1, p_max_tagged_integer, SafePredFlag);
-  Yap_InitCPred("$min_tagged_integer", 1, p_min_tagged_integer, SafePredFlag);
+  Yap_InitCPred("$break", 1, p_break, SafePredFlag);
 #ifdef BEAM
   Yap_InitCPred("@", 0, eager_split, SafePredFlag);
   Yap_InitCPred(":", 0, force_wait, SafePredFlag);
diff --git a/H/Yap.h b/H/Yap.h
index b5d4b72f0..8212df502 100755
--- a/H/Yap.h
+++ b/H/Yap.h
@@ -343,7 +343,6 @@ typedef pthread_rwlock_t rwlock_t;
 typedef enum
 {
   LANGUAGE_MODE_FLAG = 8,
-  STRICT_ISO_FLAG = 9,
   SOURCE_MODE_FLAG = 11,
   WRITE_QUOTED_STRING_FLAG = 13,
   ALLOW_ASSERTING_STATIC_FLAG = 14,
diff --git a/H/eval.h b/H/eval.h
index 46d1bcb45..04531ab15 100644
--- a/H/eval.h
+++ b/H/eval.h
@@ -42,6 +42,9 @@
 #define Int_MIN  (-Int_MAX-(CELL)1)
 #endif
 
+#define  PLMAXTAGGEDINT (MAX_ABS_INT-((CELL)1))
+#define  PLMINTAGGEDINT (-MAX_ABS_INT)
+
 #define PLMAXINT Int_MAX
 #define PLMININT Int_MIN
 
diff --git a/H/pl-basic.h b/H/pl-basic.h
index 6b5fa7c0e..7ff45093e 100644
--- a/H/pl-basic.h
+++ b/H/pl-basic.h
@@ -111,6 +111,8 @@ typedef void *pl_function_t;
 #define IGNORE_LD
 
 #define REGS_FROM_LD
+#define LD_FROM_CACHE 
+
 #else
 
 #define LOCAL_LD (__PL_ld)
@@ -126,6 +128,7 @@ typedef void *pl_function_t;
 #define IGNORE_LD (void)__PL_ld;
 
 #define REGS_FROM_LD  struct regstore_t *regcache = __PL_ld->reg_cache;
+#define LD_FROM_REGS struct PL_local_data *__PL_ld = LOCAL_PL_local_data_p;
 
 #endif
 
diff --git a/H/pl-incl.h b/H/pl-incl.h
index a1dc2f454..a1b0b0757 100755
--- a/H/pl-incl.h
+++ b/H/pl-incl.h
@@ -173,6 +173,7 @@ typedef enum
 #endif
 #if __YAP_PROLOG__
 #include "pl-yap.h"
+
 #if _WIN32
 #define __WINDOWS__ 1
 #else
@@ -533,8 +534,6 @@ extern int _PL_unify_atomic(term_t t, PL_atomic_t a);
 extern int _PL_unify_string(term_t t, word w);
 
 
-#define _PL_get_arg(X,Y,Z) PL_get_arg(X,Y,Z)
-
 extern IOSTREAM **			/* provide access to Suser_input, */
   _PL_streams(void);			/* Suser_output and Suser_error */
 
@@ -781,12 +780,14 @@ COMMON(int)             f_is_prolog_atom_start(wint_t c);
 COMMON(int)             f_is_prolog_identifier_continue(wint_t c);
 COMMON(int)             f_is_prolog_symbol(wint_t c);
 
+COMMON(int)		_PL_get_arg__LD(int index, term_t t, term_t a ARG_LD);
 
 COMMON(int) 		PL_get_atom__LD(term_t t1, atom_t *a ARG_LD);
 COMMON(int) 		PL_get_atom_ex__LD(term_t t, atom_t *a ARG_LD);
 COMMON(int)		PL_get_text__LD(term_t l, PL_chars_t *text, int flags ARG_LD);
 COMMON(int) 		PL_is_variable__LD(term_t t ARG_LD);
 COMMON(term_t) 		PL_new_term_ref__LD(ARG1_LD);
+COMMON(int) 		PL_put_atom__LD(term_t t, atom_t a ARG_LD);
 COMMON(void) 		PL_put_term__LD(term_t t1, term_t t2 ARG_LD);
 COMMON(int) 		PL_unify__LD(term_t t1, term_t t2 ARG_LD);
 COMMON(int) 		PL_unify_atom__LD(term_t t, atom_t a ARG_LD);
diff --git a/H/pl-shared.h b/H/pl-shared.h
index 1d76ef025..225640589 100644
--- a/H/pl-shared.h
+++ b/H/pl-shared.h
@@ -147,5 +147,8 @@ getUnknownModule(module_t m);
 
 COMMON(int)		debugmode(debug_type new, debug_type *old);
 COMMON(int)		tracemode(debug_type new, debug_type *old);
+COMMON(void)		Yap_setCurrentSourceLocation(IOSTREAM **s);
+
+#define SWIAtomToAtom(X) SWI_Atoms[(X)>>1]
 
 #endif /* PL_SHARED_INCLUDE */
diff --git a/H/pl-yap.h b/H/pl-yap.h
index e96208662..1aa013a36 100644
--- a/H/pl-yap.h
+++ b/H/pl-yap.h
@@ -193,10 +193,13 @@ charCode(Term w)
 #define PL_get_text(l, t, f)	PL_get_text__LD(l, t, f PASS_LD)
 #define PL_is_variable(t)	PL_is_variable__LD(t PASS_LD)
 #define PL_new_term_ref()	PL_new_term_ref__LD(PASS_LD1)
+#define PL_put_atom(t, a)	PL_put_atom__LD(t, a PASS_LD)
 #define PL_put_term(t1, t2)	PL_put_term__LD(t1, t2 PASS_LD)
 #define PL_unify_atom(t, a)	PL_unify_atom__LD(t, a PASS_LD)
 #define PL_unify_integer(t, i)	PL_unify_integer__LD(t, i PASS_LD)
 
+#define _PL_get_arg(i, t, a) _PL_get_arg__LD(i, t, a PASS_LD);
+
 #endif /* __YAP_PROLOG__ */
 
 unsigned int getUnknownModule(module_t m);
diff --git a/library/dialect/swi/fli/swi.c b/library/dialect/swi/fli/swi.c
index 204a688b5..fe69bfa53 100755
--- a/library/dialect/swi/fli/swi.c
+++ b/library/dialect/swi/fli/swi.c
@@ -207,28 +207,6 @@ X_API int PL_get_arg(int index, term_t ts, term_t a)
   return 1;
 }
    
-/* SWI: int PL_get_arg(int index, term_t t, term_t a)
-   YAP: YAP_Term YAP_ArgOfTerm(int argno, YAP_Term t)*/
-X_API int _PL_get_arg(int index, term_t ts, term_t a)
-{
-  CACHE_REGS
-  YAP_Term t = Yap_GetFromSlot(ts PASS_REGS);
-  if ( !YAP_IsApplTerm(t) ) {
-    if (YAP_IsPairTerm(t)) {
-      if (index == 1){
-	Yap_PutInSlot(a,HeadOfTerm(t) PASS_REGS);
-	return 1;
-      } else if (index == 2) {
-	Yap_PutInSlot(a,TailOfTerm(t) PASS_REGS);
-	return 1;
-      }
-    }
-    return 0;
-  }
-  Yap_PutInSlot(a,ArgOfTerm(index, t) PASS_REGS);
-  return 1;
-}
-   
 /* SWI: int PL_get_atom(term_t t, YAP_Atom *a)
    YAP: YAP_Atom YAP_AtomOfTerm(Term) */
 X_API int PL_get_atom(term_t ts, atom_t *a)
diff --git a/os/pl-prologflag.c b/os/pl-prologflag.c
index 43ffe59cd..5271cc2c6 100644
--- a/os/pl-prologflag.c
+++ b/os/pl-prologflag.c
@@ -1174,13 +1174,8 @@ initPrologFlags(void)
   setPrologFlag("max_integer",	   FT_INT64|FF_READONLY, PLMAXINT);
   setPrologFlag("min_integer",	   FT_INT64|FF_READONLY, PLMININT);
 #endif
-#ifndef __YAP_PROLOG__
   setPrologFlag("max_tagged_integer", FT_INTEGER|FF_READONLY, PLMAXTAGGEDINT);
   setPrologFlag("min_tagged_integer", FT_INTEGER|FF_READONLY, PLMINTAGGEDINT);
-#else
-  setPrologFlag("max_tagged_integer", FT_INTEGER|FF_READONLY, Int_MAX);
-  setPrologFlag("min_tagged_integer", FT_INTEGER|FF_READONLY, Int_MIN);
-#endif
 #ifdef O_GMP
   setPrologFlag("bounded",		   FT_BOOL|FF_READONLY,	   FALSE, 0);
 #ifdef __GNU_MP__
diff --git a/pl/boot.yap b/pl/boot.yap
index 28dcbe40d..1c3053108 100755
--- a/pl/boot.yap
+++ b/pl/boot.yap
@@ -93,7 +93,7 @@ true :- true.
 
 '$init_globals' :-
 	'$init_consult',
-	nb_setval('$break',0),
+	% '$swi_set_prolog_flag'(break_level, 0),
 	% '$set_read_error_handler'(error), let the user do that 
 	nb_setval('$system_mode',off),
 	nb_setval('$chr_toplevel_show_store',false).
@@ -189,7 +189,7 @@ true :- true.
 	'$clean_up_dead_clauses',
 	fail.
 '$enter_top_level' :-
-	'$nb_getval'('$break',BreakLevel,fail),
+	'$swi_current_prolog_flag'(break_level, BreakLevel),
         '$swi_current_prolog_flag'(debug, DBON),
 	(
 	 '$nb_getval'('$trace', on, fail)
@@ -208,8 +208,8 @@ true :- true.
 	get_value('$top_level_goal',GA), GA \= [], !,
 	set_value('$top_level_goal',[]),
 	'$run_atom_goal'(GA),
-	'$nb_getval'('$break',BreakLevel,fail),
-	( BreakLevel \= 0 -> true ; '$pred_exists'(halt(_), user) -> halt(0) ; '$halt'(0) ).
+	'$swi_current_prolog_flag'(break_level, BreakLevel),
+	( Breaklevel \= 0 -> true ; '$pred_exists'(halt(_), user) -> halt(0) ; '$halt'(0) ).
 '$enter_top_level' :-
 	'$run_toplevel_hooks',
 	prompt1(' ?- '),
@@ -219,7 +219,7 @@ true :- true.
 	nb_setval('$debug_run',off),
 	nb_setval('$debug_jump',off),
 	'$command'(Command,Varnames,_Pos,top),
-	'$nb_getval'('$break',BreakLevel,fail),
+	'$swi_current_prolog_flag'(break_level, BreakLevel),
 	( BreakLevel \= 0 -> true ; '$pred_exists'(halt(_), user) -> halt(0) ; '$halt'(0) ).
 
 
@@ -559,7 +559,7 @@ true :- true.
         flush_output,
 	fail.
 '$present_answer'((?-), Answ) :-
-	'$nb_getval'('$break',BL,fail),
+	'$swi_current_prolog_flag'(break_level, BL ),
 	( BL \= 0 -> 	format(user_error, '[~p] ',[BL]) ;
 			true ),
         ( recorded('$print_options','$toplevel'(Opts),_) ->
@@ -1221,7 +1221,7 @@ catch_ball(Ball, V) :-
 catch_ball(C, C).
 
 '$run_toplevel_hooks' :-
-	'$nb_getval'('$break', 0, fail),
+	'$swi_current_prolog_flag'(break_level, 0 ),
 	recorded('$toplevel_hooks',H,_), 
 	H \= fail, !,
 	( call(user:H1) -> true ; true).
diff --git a/pl/control.yap b/pl/control.yap
index d429959b7..9d4ca15e1 100644
--- a/pl/control.yap
+++ b/pl/control.yap
@@ -273,12 +273,12 @@ break :-
 	nb_getval('$debug_run',Run),
 	'$swi_current_prolog_flag'(debug, Debug),
 	'$swi_set_prolog_flag'(debug, false),
-	nb_getval('$break',BL), NBL is BL+1,
+	'$break'( true ),
 	nb_getval('$spy_gn',SPY_GN),
 	b_getval('$spy_glist',GList),
 	b_setval('$spy_glist',[]),
-	nb_setval('$break',NBL),
 	current_output(OutStream), current_input(InpStream),
+	'$swi_current_prolog_flag'(break_level, NBL ),
 	format(user_error, '% Break (level ~w)~n', [NBL]),
 	'$do_live',
 	!,
@@ -291,7 +291,7 @@ break :-
 	nb_setval('$debug_jump',Jump),
 	nb_setval('$debug_run',Run),
 	nb_setval('$trace',Trace),
-	nb_setval('$break',BL),
+	'$break'( false ),
 	nb_setval('$system_mode',SystemMode).
 
 
diff --git a/pl/flags.yap b/pl/flags.yap
index 5812f3492..153ed21ad 100755
--- a/pl/flags.yap
+++ b/pl/flags.yap
@@ -506,12 +506,10 @@ yap_flag(max_threads,X) :-
 	'$do_error'(domain_error(flag_value,max_threads+X),yap_flag(max_threads,X)).
 
 '$yap_system_flag'(agc_margin).
-'$yap_system_flag'(answer_format).
 '$yap_system_flag'(chr_toplevel_show_store).
 '$yap_system_flag'(debugger_print_options).
 '$yap_system_flag'(discontiguous_warnings).
 '$yap_system_flag'(dollar_as_lower_case).
-'$yap_system_flag'(double_quotes).
 %		V = fast  ;
 % '$yap_system_flag'(file_name_variables).
 % '$yap_system_flag'(fileerrors ).