diff --git a/C/text.c b/C/text.c
index 641b03b03..8cfaa7bb5 100644
--- a/C/text.c
+++ b/C/text.c
@@ -738,9 +738,9 @@ static Term write_number(unsigned char *s, seq_tv_t *out,
     yap_error_descriptor_t new_error;
     int i = push_text_stack();
     Yap_pushErrorContext(&new_error);
-  t = Yap_StringToNumberTerm((char *)s, &out->enc, error_on);
+  t = Yap_StringToNumberTerm((char *)s, &out->enc,true);
   pop_text_stack(i);
-    Yap_popErrorContext(true);
+    Yap_popErrorContext(error_on);
   return t;
 }
 
diff --git a/C/yap-args.c b/C/yap-args.c
index 3e2e65a42..f7deb5756 100755
--- a/C/yap-args.c
+++ b/C/yap-args.c
@@ -145,10 +145,9 @@ static void init_globals(YAP_init_args *yap_init) {
   }
 }
 
-
 const char *Yap_BINDIR, *Yap_ROOTDIR, *Yap_SHAREDIR, *Yap_LIBDIR, *Yap_DLLDIR,
-    *Yap_PLDIR, *Yap_BOOTSTRAP, *Yap_COMMONSDIR,
-  *Yap_STARTUP, *Yap_INPUT_STARTUP, *Yap_OUTPUT_STARTUP, *Yap_BOOTFILE, *Yap_INCLUDEDIR;
+    *Yap_PLDIR, *Yap_BOOTSTRAP, *Yap_COMMONSDIR, *Yap_STARTUP,
+    *Yap_INPUT_STARTUP, *Yap_OUTPUT_STARTUP, *Yap_BOOTFILE, *Yap_INCLUDEDIR;
 
 /* do initial boot by consulting the file boot.yap */
 static void consult(const char *b_file USES_REGS) {
@@ -168,7 +167,7 @@ static void consult(const char *b_file USES_REGS) {
   c_stream = YAP_InitConsult(YAP_BOOT_MODE, b_file, full, &oactive);
   if (c_stream < 0) {
     fprintf(stderr, "[ FATAL ERROR: could not open file %s ]\n", b_file);
-      pop_text_stack(lvl);
+    pop_text_stack(lvl);
     exit(1);
   }
   if (!Yap_AddAlias(AtomLoopStream, c_stream)) {
@@ -180,7 +179,8 @@ static void consult(const char *b_file USES_REGS) {
     CACHE_REGS
     YAP_Reset(YAP_FULL_RESET, false);
     Yap_StartSlots();
-      __android_log_print(ANDROID_LOG_INFO, "YAPDroid", "read %s <%d>", b_file, GLOBAL_Stream[c_stream].linecount);
+    __android_log_print(ANDROID_LOG_INFO, "YAPDroid", "read %s <%d>", b_file,
+                        GLOBAL_Stream[c_stream].linecount);
     Term vs = YAP_MkVarTerm(), pos = MkVarTerm();
     t = YAP_ReadClauseFromStream(c_stream, vs, pos);
     // Yap_GetNèwSlot(t);
@@ -213,42 +213,30 @@ static void consult(const char *b_file USES_REGS) {
 
 ///
 ///
-  static const char * sel(bool dir, ...) {
-  CACHE_REGS
-  va_list args;
-  va_start(args ,dir);
-  while (true) {
-  bool init = va_arg(args, int);
-    const char *fmt = va_arg(args, char *);
-    if (init) {
-      va_end(args);
-      return fmt;
-
-    }
-  }
+static const char *sel(bool dir, bool ok1, const char *s1, bool ok2, const char *s2,
+                       ...) {
+  if (ok1 && s1)
+    return s1;
+  if (ok2)
+    return s2;
   return NULL;
 }
 
-static const char * join(const char *s, ...) {
+static const char *join(const char *s0, const char *s1) {
   CACHE_REGS
-  va_list args;
-  va_start(args , s);
+
+  if (!s0 || s0[0] == '\0')
+    return s1;
+  if (!s1 || s1[0] == '\0')
+    return s0;
   //  int lvl = push_text_stack();
-  char *buf = malloc(FILENAME_MAX+1);
-  if (s && s[0])
-    strcpy(buf, s);
-  while (true) {
-    const char *fmt = va_arg(args, char *);
-    if (fmt == NULL) {
-      va_end(args);
-      //    return pop_output_text_stack(lvl,buf);
-      return buf;
-    }
-    strcat(buf, fmt);
-  }
+  char *buf = malloc(FILENAME_MAX + 1);
+  strcpy(buf, s0);
+  strcat(buf, s1);
+  return buf;
 }
 
- static void Yap_set_locations(YAP_init_args *iap) {
+static void Yap_set_locations(YAP_init_args *iap) {
 
   /// ROOT_DIR is the home of the YAP system. It can be:
   /// -- provided by the user;
@@ -257,126 +245,104 @@ static const char * join(const char *s, ...) {
   /// It is:
   //  --_not useful in Android, WIN32;
   /// -- DESTDIR/ in Anaconda
-  /// -- /usr/local in most Unix style systems
-  Yap_ROOTDIR = sel(true, iap->ROOTDIR != NULL, iap->ROOTDIR,
-		       true,
+  /// -- /usr/locall in most Unix style systems
+  Yap_ROOTDIR = sel(true, iap->ROOTDIR != NULL, iap->ROOTDIR, true,
 #if __ANDROID__
-			NULL,
+                    NULL,
 #else
-		    join(getenv("DESTDIR"),YAP_ROOTDIR, NULL),
+                    join(getenv("DESTDIR"), YAP_ROOTDIR),
 #endif
-		    false
-		    );
+                    false);
   /// BINDIR: where the OS stores header files, namely libYap...
-  Yap_BINDIR = sel(true,
-		   iap->BINDIR != NULL, iap->BINDIR,
-		   true,
+  Yap_BINDIR = sel(true, iap->BINDIR != NULL, iap->BINDIR, true,
 #if __ANDROID__
-		   NULL,
+                   NULL,
 #else
-		   join(getenv("DESTDIR"),YAP_BINDIR, NULL),
+                   join(getenv("DESTDIR"), YAP_BINDIR),
 #endif
-		      false    );
+                   false);
   /// LIBDIR: where the OS stores dynamic libraries, namely libYap...
-  Yap_LIBDIR = sel(true,
-		      iap->LIBDIR != NULL, iap->LIBDIR,
-		      true,
+  Yap_LIBDIR = sel(true, iap->LIBDIR != NULL, iap->LIBDIR, true,
 #if __ANDROID__
-		      NULL,
+                   NULL,
 #else
-		   join(getenv("DESTDIR"),YAP_LIBDIR,NULL),
+                   join(getenv("DESTDIR"), YAP_LIBDIR),
 #endif
-		      false    );
+                   false);
   /// DLLDIR: where libraries can find expicitely loaded DLLs
-  Yap_DLLDIR = sel(true,
-		      iap->DLLDIR != NULL, iap->DLLDIR,
-		      true,
+  Yap_DLLDIR = sel(true, iap->DLLDIR != NULL, iap->DLLDIR, true,
 #if __ANDROID__
-			NULL
+                   NULL
 #else
-		   join(getenv("DESTDIR"),YAP_DLLDIR, NULL),
+                   join(getenv("DESTDIR"), YAP_DLLDIR),
 #endif
-			false    );
+                   false);
   /// INCLUDEDIR: where the OS stores header files, namely libYap...
-  Yap_INCLUDEDIR = sel(true,
-		      iap->INCLUDEDIR != NULL, iap->INCLUDEDIR,
-		      true,
+  Yap_INCLUDEDIR = sel(true, iap->INCLUDEDIR != NULL, iap->INCLUDEDIR, true,
 #if __ANDROID__
-		      NULL,
+                       NULL,
 #else
-		       join(getenv("DESTDIR"),YAP_INCLUDEDIR, NULL),
+                       join(getenv("DESTDIR"), YAP_INCLUDEDIR),
 #endif
-		      false    );
+                       false);
   /// SHAREDIR: where OS & ARCH independent files live
-  Yap_SHAREDIR = sel(true,
-		      iap->SHAREDIR != NULL, iap->SHAREDIR,
-		      true,
+  Yap_SHAREDIR = sel(true, iap->SHAREDIR != NULL, iap->SHAREDIR, true,
 #if __ANDROID__
-			"/assets",
+                     "/assets",
 #else
-		      join(getenv("DESTDIR"),YAP_SHAREDIR, NULL),
+                     join(getenv("DESTDIR"), YAP_SHAREDIR),
 #endif
-			false    );
+                     false);
   /// PLDIR: where we can find Prolog files
-  Yap_PLDIR = sel(true,
-		      iap->PLDIR != NULL, iap->PLDIR,
-		      true,
+  Yap_PLDIR = sel(true, iap->PLDIR != NULL, iap->PLDIR, true,
 #if __ANDROID__
-		      "/assets/Yap",
+                  "/assets/Yap",
 #else
-		  join(getenv("DESTDIR"),YAP_PLDIR, NULL),
+                  join(getenv("DESTDIR"), YAP_PLDIR),
 #endif
-		     false    );
+                  false);
   /// ``COMMONSDIR: Prolog Commons
- Yap_COMMONSDIR = sel(true,
-		      iap->COMMONSDIR != NULL, iap->COMMONSDIR,
-		      true,
+  Yap_COMMONSDIR = sel(true, iap->COMMONSDIR != NULL, iap->COMMONSDIR, true,
 #if __ANDROID__
-		      "/assets/PrologCommons",
+                       "/assets/PrologCommons",
 #else
-		      join(getenv("DESTDIR"),YAP_SHAREDIR "/PrologCommons", NULL),
+                       join(getenv("DESTDIR"), YAP_SHAREDIR "/PrologCommons"),
 #endif
-			false    );
- /// BOOTPLDIR: where we can find Prolog bootstrap files
-   Yap_BOOTSTRAP = sel(true,
-		      iap->BOOTSTRAP != NULL, iap->BOOTSTRAP,
-		      true,
+                       false);
+  /// BOOTPLDIR: where we can find Prolog bootstrap files
+  Yap_BOOTSTRAP = sel(true, iap->BOOTSTRAP != NULL, iap->BOOTSTRAP, true,
 #if __ANDROID__
-		      "/assets/Yap/pl",
+                      "/assets/Yap/pl",
 #else
-		     join(getenv("DESTDIR"),YAP_BOOTSTRAP, NULL),
+                      join(getenv("DESTDIR"), YAP_BOOTSTRAP),
 #endif
-			false    );
- /// BOOTFILE: where we can find the core Prolog bootstrap file
- Yap_BOOTFILE = sel(false,
-		      iap->BOOTFILE != NULL, iap->BOOTFILE,
-		      true,
+                      false);
+  /// BOOTFILE: where we can find the core Prolog bootstrap file
+  Yap_BOOTFILE = sel(false, iap->BOOTFILE != NULL, iap->BOOTFILE, true,
 #if __ANDROID__
-		      "/assets/Yap/pl/boot.yap",
+                     "/assets/Yap/pl/boot.yap",
 #else
-		    join(getenv("DESTDIR"),YAP_BOOTFILE, NULL),
+                     join(getenv("DESTDIR"), YAP_BOOTFILE),
 #endif
-			false    );
- /// STARTUP: where we can find the core Prolog bootstrap file
-   Yap_OUTPUT_STARTUP = sel(false,
-                            iap->OUTPUT_STARTUP != NULL, iap->OUTPUT_STARTUP,
-                            true,
+                     false);
+  /// STARTUP: where we can find the core Prolog bootstrap file
+  Yap_OUTPUT_STARTUP =
+      sel(false, iap->OUTPUT_STARTUP != NULL, iap->OUTPUT_STARTUP, true,
 #if __ANDROID__
-           NULL,
+          NULL,
 #else
-                            join(getenv("DESTDIR"),YAP_OUTPUT_STARTUP,NULL),
+          join(getenv("DESTDIR"), YAP_OUTPUT_STARTUP),
 #endif
-                            false    );
-   Yap_INPUT_STARTUP = sel(false,
-                            iap->INPUT_STARTUP != NULL, iap->INPUT_STARTUP,
-                            true,
+          false);
+  Yap_INPUT_STARTUP =
+      sel(false, iap->INPUT_STARTUP != NULL, iap->INPUT_STARTUP, true,
 #if __ANDROID__
-           NULL,
+          NULL,
 #else
-                            join(getenv("DESTDIR"),YAP_INPUT_STARTUP,NULL),
+          join(getenv("DESTDIR"), YAP_INPUT_STARTUP),
 #endif
-                            false    );
- if (Yap_ROOTDIR)
+          false);
+  if (Yap_ROOTDIR)
     setAtomicGlobalPrologFlag(HOME_FLAG,
                               MkAtomTerm(Yap_LookupAtom(Yap_ROOTDIR)));
   if (Yap_PLDIR)
@@ -975,7 +941,7 @@ static void init_hw(YAP_init_args *yap_init, struct ssz_t *spt) {
 #if __ANDROID__
 
   // if (yap_init->assetManager)
-  //Yap_InitAssetManager();
+  // Yap_InitAssetManager();
 
 #endif
 
@@ -1007,7 +973,7 @@ static YAP_file_type_t end_init(YAP_init_args *yap_init, YAP_file_type_t rc) {
   return rc;
 }
 
- static void start_modules(void) {
+static void start_modules(void) {
   Term cm = CurrentModule;
   size_t i;
   for (i = 0; i < n_mdelays; i++) {
@@ -1017,7 +983,6 @@ static YAP_file_type_t end_init(YAP_init_args *yap_init, YAP_file_type_t rc) {
   CurrentModule = cm;
 }
 
-
 /* this routine is supposed to be called from an external program
    that wants to control Yap */
 
@@ -1027,8 +992,8 @@ X_API YAP_file_type_t YAP_Init(YAP_init_args *yap_init) {
   struct ssz_t minfo;
 
   if (YAP_initialized)
-  /* ignore repeated calls to YAP_Init */
-  return YAP_FOUND_BOOT_ERROR;
+    /* ignore repeated calls to YAP_Init */
+    return YAP_FOUND_BOOT_ERROR;
   if (!LOCAL_TextBuffer)
     LOCAL_TextBuffer = Yap_InitTextAllocator();
 
@@ -1058,8 +1023,10 @@ X_API YAP_file_type_t YAP_Init(YAP_init_args *yap_init) {
   Yap_ExecutionMode = yap_init->ExecutionMode;
   Yap_set_locations(yap_init);
 
-  if (!do_bootstrap && Yap_INPUT_STARTUP && yap_init->boot_file_type != YAP_BOOT_PL &&
-      Yap_SavedInfo(Yap_INPUT_STARTUP, &minfo.Trail, &minfo.Stack, &minfo.Heap) &&
+  if (!do_bootstrap && Yap_INPUT_STARTUP &&
+      yap_init->boot_file_type != YAP_BOOT_PL &&
+      Yap_SavedInfo(Yap_INPUT_STARTUP, &minfo.Trail, &minfo.Stack,
+                    &minfo.Heap) &&
       Yap_Restore(Yap_INPUT_STARTUP)) {
     setBooleanGlobalPrologFlag(SAVED_PROGRAM_FLAG, true);
     CurrentModule = LOCAL_SourceModule = USER_MODULE;
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 30f0d0d97..4c0410eb0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -294,7 +294,7 @@ set(datadir ${CMAKE_INSTALL_PREFIX}/share) #DATADIR})
 set(mandir ${CMAKE_INSTALL_PREFIX}/share/man) #MANDIR})
 set(docdir ${CMAKE_INSTALL_PREFIX}/share/docs) #MANDIR})
 
-set(libpl ${datarootdir}/Yap)
+set(libpl ${datadir}/Yap)
 
 set(dlls ${libdir}/Yap)
 
diff --git a/CXX/yapi.cpp b/CXX/yapi.cpp
index 6db3510d5..c30e903e5 100644
--- a/CXX/yapi.cpp
+++ b/CXX/yapi.cpp
@@ -458,14 +458,14 @@ bool YAPEngine::mgoal(Term t, Term tmod) {
     CACHE_REGS
     BACKUP_MACHINE_REGS();
     Term *ts = nullptr;
-      Yap_DebugPlWriteln(tmod);
       if (IsStringTerm(tmod))
           tmod = MkAtomTerm(Yap_LookupAtom(StringOfTerm(tmod)));
     PredEntry *ap = (new YAPPredicate(t, tmod, ts, "C++"))->ap;
-      Yap_DebugPlWriteln(t);
     if (ap == nullptr || ap->OpcodeOfPred == UNDEF_OPCODE) {
       ap = rewriteUndefEngineQuery(ap, t, tmod);
     }
+    if (IsApplTerm(t)) ts = RepAppl(t)+1;
+    else if (IsPairTerm(t)) ts = RepPair(t);
     /* legal ap */
     arity_t arity = ap->ArityOfPE;
 
@@ -739,12 +739,12 @@ PredEntry *YAPQuery::rewriteUndefQuery() {
   return ap = PredCall;
 }
 
-PredEntry *YAPEngine::rewriteUndefEngineQuery(PredEntry *a, Term tgoal,
+PredEntry *YAPEngine::rewriteUndefEngineQuery(PredEntry *a, Term &tgoal,
                                               Term mod) {
   Term ts[2];
   ts[0] = mod;
   ts[1] = tgoal;
-  ARG1 = Yap_MkApplTerm(FunctorModule, 2, ts);
+  ARG1 = tgoal = Yap_MkApplTerm(FunctorModule, 2, ts);
   //goal = YAPTerm(Yap_MkApplTerm(FunctorMetaCall, 1, &ARG1));
   return PredCall;
   
diff --git a/CXX/yapq.hh b/CXX/yapq.hh
index 9afd2561d..cf5f31101 100644
--- a/CXX/yapq.hh
+++ b/CXX/yapq.hh
@@ -217,12 +217,14 @@ public:
 
   inline bool getMaxTrailSize() { return MaxTrailSize; };
 
-  inline void setLibDir(const char *fl) {
+  inline void setPLDIR(const char *fl) {
     LIBDIR = (const char *)malloc(strlen(fl) + 1);
     strcpy((char *)LIBDIR, fl);
   };
 
-  inline const char *setINPUT_STARTUP(const char *fl) {
+  inline const char *getPLDIR() { return PLDIR; };
+
+  inline void setINPUT_STARTUP(const char *fl) {
     INPUT_STARTUP = (const char *)malloc(strlen(fl) + 1);
     strcpy((char *)INPUT_STARTUP, fl);
   };
@@ -290,7 +292,7 @@ private:
   YAPError yerror;
   void doInit(YAP_file_type_t BootMode, YAPEngineArgs *cargs);
   YAP_dogoalinfo q;
-  PredEntry *rewriteUndefEngineQuery(PredEntry *ap, Term t, Term tmod);
+  PredEntry *rewriteUndefEngineQuery(PredEntry *ap, Term &t, Term tmod);
 
 public:
   /// construct a new engine; may use a variable number of arguments
diff --git a/config.h.cmake b/config.h.cmake
index b7236931b..2bf5293f7 100644
--- a/config.h.cmake
+++ b/config.h.cmake
@@ -2002,6 +2002,15 @@ significant byte first (like Motorola and SPARC, unlike Intel). */
 #define YAP_DLLDIR "${YAP_LIBDIR}/Yap"
 #endif
 
+/* run-time boot */
+#ifndef YAP_INPUT_STARTUP
+#define YAP_INPUT_STARTUP "${YAP_DLLDIR}/${YAP_STARTUP}"
+#endif
+
+/* init-time boot */
+#ifndef YAP_OUTPUT_STARTUP
+#define YAP_OUTPUT_STARTUP "${CMAKE_BINARY_DIR}/${YAP_STARTUP}"
+#endif
 
 /* name of YAP JIT library */
 #ifndef YAP_YAPJITLIB
@@ -2009,17 +2018,17 @@ significant byte first (like Motorola and SPARC, unlike Intel). */
 #endif
 
 #ifndef YAP_SHAREDIR
-#define YAP_SHAREDIR  "${YAP_ROOTDIR}/share"
+#define YAP_SHAREDIR  "${YAP_DATADIR}"
 #endif
 
 /* name of YAP PL library */
 #ifndef YAP_PLDIR
-#define YAP_PLDIR "${YAP_SHAREDIR}/Yap"
+#define YAP_PLDIR "${YAP_PLDIR}"
 #endif
 
 /* name of Commons library */
 #ifndef YAP_COMMONSDIR
-#define YAP COMMONSDIR "${YAP_SHAREDIR}/PrologCommmons"
+#define YAP COMMONSDIR "${YAP_DATADIR}/PrologCommmons"
 #endif
 
 
@@ -2035,16 +2044,6 @@ significant byte first (like Motorola and SPARC, unlike Intel). */
 
 
 
-/* run-time boot */
-#ifndef YAP_INPUT_STARTUP
-#define YAP_INPUT_STARTUP "${YAP_DLLDIR}/${YAP_STARTUP}"
-#endif
-
-/* init-time boot */
-#ifndef YAP_OUTPUT_STARTUP
-#define YAP_OUTPUT_STARTUP "${CMAKE_BINARY_DIR}/${YAP_STARTUP}"
-#endif
-
 /* HP-UX old socket stuff */
 #ifndef _XOPEN_SOURCE
 #cmakedefine _XOPEN_SOURCE "${_XOPEN_SOURCE}"
diff --git a/include/YapError.h b/include/YapError.h
index ada04ff9b..579a77c56 100644
--- a/include/YapError.h
+++ b/include/YapError.h
@@ -1,16 +1,16 @@
 /*************************************************************************
- *									 *
- *	 YAP Prolog 	%W% %G% 					 *
- *	Yap Prolog was developed at NCCUP - Universidade do Porto	 *
- *									 *
- * Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997	 *
- *									 *
- **************************************************************************
- *									 *
- * File:		YapError.h * mods:
- ** comments:	error header file for YAP				 *
- * version:      $Id: Yap.h,v 1.38 2008-06-18 10:02:27 vsc Exp $	 *
- *************************************************************************/
+   *									 *
+   *	 YAP Prolog 	%W% %G% 					 *
+   *	Yap Prolog was developed at NCCUP - Universidade do Porto	 *
+   *									 *
+   * Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997	 *
+   *									 *
+   **************************************************************************
+   *									 *
+   * File:		YapError.h * mods:
+   ** comments:	error header file for YAP				 *
+   * version:      $Id: Yap.h,v 1.38 2008-06-18 10:02:27 vsc Exp $	 *
+   *************************************************************************/
 
 #ifndef YAP_ERROR_H
 #define YAP_ERROR_H 1
@@ -37,13 +37,16 @@
 
 #define MAX_ERROR_MSG_SIZE 1024
 
-extern void Yap_InitError__(const char *file, const char *function, int lineno, yap_error_number e, YAP_Term g, ...);
+    extern void
+    Yap_InitError__(const char *file, const char *function, int lineno,
+                    yap_error_number e, YAP_Term g, ...);
 
-extern struct yami *Yap_Error__(const char *file, const char *function, int lineno,
-                         yap_error_number err, YAP_Term wheret, ...);
+extern struct yami *Yap_Error__(const char *file, const char *function,
+                                int lineno, yap_error_number err,
+                                YAP_Term wheret, ...);
 
 extern void Yap_ThrowError__(const char *file, const char *function, int lineno,
-                      yap_error_number err, YAP_Term wheret, ...)
+                             yap_error_number err, YAP_Term wheret, ...)
 #ifndef MSC_VER
     __attribute__((noreturn))
 #endif
@@ -52,7 +55,7 @@ extern void Yap_ThrowError__(const char *file, const char *function, int lineno,
 #define Yap_NilError(id, ...)                                                  \
   Yap_Error__(__FILE__, __FUNCTION__, __LINE__, id, TermNil, __VA_ARGS__)
 
-#define Yap_InitError(id, ...)                                                  \
+#define Yap_InitError(id, ...)                                                 \
   Yap_InitError__(__FILE__, __FUNCTION__, __LINE__, id, TermNil, __VA_ARGS__)
 
 #define Yap_Error(id, inp, ...)                                                \
diff --git a/library/CMakeLists.txt b/library/CMakeLists.txt
index f39857656..50c709b43 100644
--- a/library/CMakeLists.txt
+++ b/library/CMakeLists.txt
@@ -55,7 +55,6 @@ set (LIBRARY_PL
   wgraphs.yap
   wundgraphs.yap
   lam_mpi.yap
-  ypp.yap
    ytest.yap
    c_alarms.yap
   flags.yap
diff --git a/os/alias.c b/os/alias.c
index 96c8dd97d..2a92e652f 100644
--- a/os/alias.c
+++ b/os/alias.c
@@ -225,6 +225,12 @@ Yap_SetAlias (Atom arg, int sno)
     // replace alias
     if (aliasp->name == arg) {
       aliasp->alias_stream = sno;
+      if (arg == AtomUserIn)
+	  LOCAL_c_input_stream = sno;
+       if (arg == AtomUserOut)
+	  LOCAL_c_output_stream = sno;
+       if (arg == AtomUserErr)
+	  LOCAL_c_error_stream = sno;
       return;
     }
     aliasp++;
@@ -310,6 +316,18 @@ ExistsAliasForStream (int sno, Atom al)
 
   while (aliasp < aliasp_max) {
     if (aliasp->alias_stream == sno && aliasp->name == al) {
+       if (al == AtomUserIn) {
+	  LOCAL_c_input_stream = StdInStream;
+	  aliasp->alias_stream = StdInStream;
+      }
+       if (al == AtomUserOut) {
+	  LOCAL_c_output_stream = StdOutStream;
+	  aliasp->alias_stream = StdOutStream;
+      }
+      if (al == AtomUserErr) {
+	LOCAL_c_error_stream = StdErrStream;
+	  aliasp->alias_stream = StdErrStream;
+      }
       return true;
     }
     aliasp++;
diff --git a/os/encoding.h b/os/encoding.h
index a4141bad5..bac5bbf39 100644
--- a/os/encoding.h
+++ b/os/encoding.h
@@ -26,7 +26,7 @@
 
 #endif
 
-typedef enum {
+typedef enum YAP_encoding {
   ENC_OCTET = 0,          /// binary files
   ENC_ISO_LATIN1 = 1,     /// US+West Europe
   ENC_ISO_ASCII = 2,      /// US only
diff --git a/os/iopreds.c b/os/iopreds.c
index 7522b1aa3..3035c5f33 100644
--- a/os/iopreds.c
+++ b/os/iopreds.c
@@ -315,57 +315,8 @@ static void unix_upd_stream_info(StreamDesc *s) {
   s->status |= Seekable_Stream_f;
 }
 
-void Yap_DefaultStreamOps(StreamDesc *st) {
-  CACHE_REGS
-  st->stream_wputc = put_wchar;
-  if (st->encoding == ENC_ISO_UTF8)
-    st->stream_wgetc = get_wchar_UTF8;
-  else
-    st->stream_wgetc = get_wchar;
-  if (st->vfs) {
-    st->stream_putc = st->vfs->put_char;
-    st->stream_wgetc = st->vfs->get_char;
-  } else {
-    st->stream_putc = FilePutc;
-    st->stream_getc = PlGetc;
-  }
-  if (st->status & Pipe_Stream_f) {
-    Yap_PipeOps(st);
-  } else if (st->status & InMemory_Stream_f) {
-    Yap_MemOps(st);
-  } else if (st->status & Tty_Stream_f) {
-    Yap_ConsoleOps(st);
-  } else {
-    unix_upd_stream_info(st);
-  }
-  if (st->status & (Promptable_Stream_f)) {
-    Yap_ConsoleOps(st);
-  }
-#ifndef _WIN32
-  else if (st->file != NULL && 0 && !(st->status & InMemory_Stream_f)) {
-    st->stream_wgetc = get_wchar_from_file;
-  }
-#endif
-  if (st->buf.on) {
-    st->stream_getc = Yap_popChar;
-    st->stream_wgetc = Yap_popChar;
-  }
-#if USE_READLINE
-  if (st->status & Readline_Stream_f) {
-      st->stream_peek = Yap_ReadlinePeekChar;
-      st->stream_wpeek = Yap_ReadlinePeekChar;
-    }
-  /* else {
-      st->stream_peek = Yap_peekWithGetc;
-      st->stream_wpeek = Yap_peekWideWithGetwc;
-    }
-  } else if (st->status & Seekable_Stream_f) {
-    st->stream_peek = Yap_peekWithSeek;
-    st->stream_wpeek = Yap_peekWideWithSeek;
-    } */
-  else
-#endif
-    {
+static void default_peek(StreamDesc *st) {
+  {
     st->stream_peek = Yap_peekChar;
     st->stream_wpeek = Yap_peekWide;
   }
@@ -381,6 +332,64 @@ void Yap_DefaultStreamOps(StreamDesc *st) {
     st->stream_wgetc_for_read = st->stream_wgetc;
 }
 
+void Yap_DefaultStreamOps(StreamDesc *st) {
+  CACHE_REGS
+
+  st->stream_wputc = put_wchar;
+  st->stream_wgetc = get_wchar;
+  if (st->vfs) {
+    st->stream_putc = st->vfs->put_char;
+    st->stream_wputc = st->vfs->put_char;
+    st->stream_getc = st->vfs->get_char;
+    st->stream_wgetc = st->vfs->get_char;
+    default_peek(st);
+    return;
+  } else {
+    if (st->encoding == ENC_ISO_UTF8)
+      st->stream_wgetc = get_wchar_UTF8;
+    st->stream_putc = FilePutc;
+    st->stream_getc = PlGetc;
+    if (st->status & Pipe_Stream_f) {
+      Yap_PipeOps(st);
+    } else if (st->status & InMemory_Stream_f) {
+      Yap_MemOps(st);
+    } else if (st->status & Tty_Stream_f) {
+      Yap_ConsoleOps(st);
+    } else {
+      unix_upd_stream_info(st);
+    }
+    if (st->status & (Promptable_Stream_f)) {
+      Yap_ConsoleOps(st);
+    }
+#ifndef _WIN32
+    else if (st->file != NULL && 0 && !(st->status & InMemory_Stream_f)) {
+      st->stream_wgetc = get_wchar_from_file;
+    }
+#endif
+    if (st->buf.on) {
+      st->stream_getc = Yap_popChar;
+      st->stream_wgetc = Yap_popChar;
+    }
+  }
+#if USE_READLINE
+  if (st->status & Readline_Stream_f) {
+    st->stream_peek = Yap_ReadlinePeekChar;
+    st->stream_wpeek = Yap_ReadlinePeekChar;
+  }
+
+  /* else {
+      st->stream_peek = Yap_peekWithGetc;
+      st->stream_wpeek = Yap_peekWideWithGetwc;
+    }
+  } else if (st->status & Seekable_Stream_f) {
+    st->stream_peek = Yap_peekWithSeek;
+    st->stream_wpeek = Yap_peekWideWithSeek;
+    } */
+  else
+#endif
+    default_peek(st);
+}
+
 static void InitFileIO(StreamDesc *s) {
   CACHE_REGS
   Yap_DefaultStreamOps(s);
@@ -1279,16 +1288,16 @@ do_open(Term file_name, Term t2,
                  : false) ||
             trueGlobalPrologFlag(OPEN_EXPANDS_FILENAME_FLAG);
   // expand file name?
-    int lvl = push_text_stack();
+  int lvl = push_text_stack();
   const char *fname = Yap_AbsoluteFile(fname0, ok);
 
   if (!fname) {
-      pop_text_stack(lvl);
+    pop_text_stack(lvl);
     PlIOError(EXISTENCE_ERROR_SOURCE_SINK, ARG1, NULL);
   }
 
   // Skip scripts that start with !#/.. or similar
-    pop_text_stack(lvl);
+  pop_text_stack(lvl);
   bool script =
       (args[OPEN_SCRIPT].used ? args[OPEN_SCRIPT].tvalue == TermTrue : false);
   // binary type
@@ -1309,8 +1318,8 @@ do_open(Term file_name, Term t2,
 #endif
       /* note that this matters for UNICODE style  conversions */
     } else {
-        pop_text_stack(lvl);
-        Yap_Error(DOMAIN_ERROR_STREAM, tlist,
+      pop_text_stack(lvl);
+      Yap_Error(DOMAIN_ERROR_STREAM, tlist,
                 "type is ~a, must be one of binary or text", t);
     }
   }
@@ -1336,13 +1345,14 @@ do_open(Term file_name, Term t2,
   } else if (open_mode == AtomAppend) {
     strncpy(io_mode, "a", 8);
   } else {
-      pop_text_stack(lvl);
+    pop_text_stack(lvl);
     return false;
   }
   if ((sno = Yap_OpenStream(fname, io_mode, file_name)) < 0) {
-      pop_text_stack(lvl);
+    pop_text_stack(lvl);
     return false;
   }
+
   st = &GLOBAL_Stream[sno];
   st->user_name = file_name;
   // user requested encoding?
@@ -1374,11 +1384,11 @@ do_open(Term file_name, Term t2,
   else
     st->encoding = encoding;
   if (script) {
-      open_header(sno, open_mode);
+    open_header(sno, open_mode);
   }
-    pop_text_stack(lvl);
+  pop_text_stack(lvl);
 
-    free(args);
+  free(args);
   UNLOCK(st->streamlock);
   {
     Term t = Yap_MkStream(sno);
@@ -1501,16 +1511,17 @@ static Int p_file_expansion(USES_REGS1) { /* '$file_expansion'(+File,-Name) */
     PlIOError(INSTANTIATION_ERROR, file_name, "absolute_file_name/3");
     return (FALSE);
   }
-    int lvl = push_text_stack();
-   const char *tmp;
-  if ((tmp=Yap_AbsoluteFile(RepAtom(AtomOfTerm(file_name))->StrOfAE, false)) ==  NULL) {
-      pop_text_stack(lvl);
-      return (PlIOError(EXISTENCE_ERROR_SOURCE_SINK, file_name,
-                        "absolute_file_name/3"));
+  int lvl = push_text_stack();
+  const char *tmp;
+  if ((tmp = Yap_AbsoluteFile(RepAtom(AtomOfTerm(file_name))->StrOfAE,
+                              false)) == NULL) {
+    pop_text_stack(lvl);
+    return (PlIOError(EXISTENCE_ERROR_SOURCE_SINK, file_name,
+                      "absolute_file_name/3"));
   }
   bool rc = (Yap_unify(ARG2, MkAtomTerm(Yap_LookupAtom(tmp))));
-    pop_text_stack(lvl);
-    return rc;
+  pop_text_stack(lvl);
+  return rc;
 }
 
 static Int p_open_null_stream(USES_REGS1) {
@@ -1565,7 +1576,7 @@ int Yap_OpenStream(const char *fname, const char *io_mode, Term user_name) {
   // read, write, append
   st->file = NULL;
   st->status = 0;
-  //fname = Yap_VF(fname);
+  // fname = Yap_VF(fname);
   if ((vfsp = vfs_owner(fname)) != NULL) {
     if (!vfsp->open(vfsp, sno, fname, "r")) {
       UNLOCK(st->streamlock);
@@ -1573,7 +1584,7 @@ int Yap_OpenStream(const char *fname, const char *io_mode, Term user_name) {
                 "%s", fname);
       return -1;
     }
-      vfsp = GLOBAL_Stream[sno].vfs;
+    vfsp = GLOBAL_Stream[sno].vfs;
   } else {
     fd = st->file = fopen(fname, io_mode);
     if (fd == NULL) {
diff --git a/os/streams.c b/os/streams.c
index c72fc9e94..4ff0ec45b 100644
--- a/os/streams.c
+++ b/os/streams.c
@@ -1109,7 +1109,6 @@ bool Yap_SetOutputStream( Term sd )
       Yap_CheckStream(sd, Output_Stream_f | Append_Stream_f, "set_output/2");
   if (sno < 0)
     return false;
-  LOCAL_c_output_stream = sno;
   UNLOCK(GLOBAL_Stream[sno].streamlock);
   Yap_SetAlias(AtomUserOut, sno);
   return true;
diff --git a/os/writeterm.c b/os/writeterm.c
index f61cd85bb..3bd01145c 100644
--- a/os/writeterm.c
+++ b/os/writeterm.c
@@ -600,6 +600,7 @@ static Int writeln(USES_REGS1) {
     return false;
   }
   int output_stream = Yap_CheckTextStream(ARG1, Output_Stream_f, "writeln/2");
+  fprintf(stderr,"writeln %d\n", output_stream);
   if (output_stream < 0) {
     free(args);
     return false;
diff --git a/packages/python/CMakeLists.txt b/packages/python/CMakeLists.txt
index b44c66a60..17787b257 100644
--- a/packages/python/CMakeLists.txt
+++ b/packages/python/CMakeLists.txt
@@ -1,7 +1,7 @@
 
 #CHECK: PythonLibs, changed to work in WIN32
 
-set (PYTHON_SOURCES python.c pl2py.c pybips.c py2pl.c pl2pl.c pypreds.c)
+set (PYTHON_SOURCES python.c pl2py.c pybips.c py2pl.c pl2pl.c pypreds.c pyio.c)
 set (PYTHON_HEADERS py4yap.h)
 set (CMAKE_POSITION_INDEPENDENT_CODE TRUE)
 
diff --git a/packages/python/py4yap.h b/packages/python/py4yap.h
index 1cd70f1ad..b6418ed20 100644
--- a/packages/python/py4yap.h
+++ b/packages/python/py4yap.h
@@ -56,8 +56,10 @@ extern X_API PyObject *yap_to_python(YAP_Term t, bool eval, PyObject *o,
                                      bool cvt);
 extern X_API PyObject *string_to_python(const char *s, bool eval, PyObject *p0);
 typedef YAP_Arity arity_t;
+extern  bool init_python_vfs(void);
 
-extern atom_t ATOM_true, ATOM_false, ATOM_colon, ATOM_dot, ATOM_none, ATOM_t,
+
+        extern atom_t ATOM_true, ATOM_false, ATOM_colon, ATOM_dot, ATOM_none, ATOM_t,
     ATOM_comma, ATOM_builtin, ATOM_V, ATOM_A, ATOM_self, ATOM_nil,
     ATOM_brackets, ATOM_curly_brackets;
 
diff --git a/packages/python/pyio.c b/packages/python/pyio.c
new file mode 100644
index 000000000..026ca94f8
--- /dev/null
+++ b/packages/python/pyio.c
@@ -0,0 +1,122 @@
+
+
+#include "py4yap.h"
+#include <VFS.h>
+
+#include "YapStreams.h"
+
+VFS_t pystream;
+
+static void *py_open(VFS_t *me, int sno, const char *name,
+                     const char *io_mode) {
+#if HAVE_STRCASESTR
+  if (strcasestr(name, "/python/") == name)
+    name += strlen("/python/");
+#else
+  if (strstr(name, "/python/") == name)
+    name += strlen("/python/");
+#endif
+  StreamDesc *st = YAP_RepStreamFromId(sno);
+  // we assume object is already open, so there is no need to open it.
+  PyObject *stream = string_to_python(name, true, NULL);
+  if (stream == Py_None)
+    return NULL;
+  Py_INCREF(stream);
+  st->u.private_data = stream;
+  st->vfs = me;
+  st->name = YAP_LookupAtom(name);
+  st->user_name = YAP_MkAtomTerm(st->name);
+  return stream;
+}
+
+static bool py_close(int sno) { return true; }
+
+static int py_put(int sno, int ch) {
+  // PyObject *pyw; // buffer
+  // int pyw_kind;
+  // PyObject *pyw_data;
+  // PySys_WriteStdout("%C", ch);
+  //  return ch;
+  char s[2];
+  StreamDesc *st = YAP_GetStreamFromId(sno);
+  //  PyUnicode_WRITE(pyw_kind, pyw_data, 0, ch);
+  PyObject *err, *fput = PyObject_GetAttrString(st->u.private_data, "write");
+  s[0] = ch;
+  s[1] = '\0';
+  PyObject_CallMethodObjArgs(st->u.private_data, PyUnicode_FromString("write"),
+                             PyUnicode_FromString(s), NULL);
+  if ((err = PyErr_Occurred())) {
+    PyErr_SetString(
+        err,
+        "Error in put\n"); // %s:%s:%d!\n", __FILE__, __FUNCTION__, __LINE__);
+  }
+  return ch;
+}
+
+static int py_get(int sno) {
+  StreamDesc *s = YAP_GetStreamFromId(sno);
+  PyObject *fget = PyObject_GetAttrString(s->u.private_data, "read");
+  PyObject *pyr = PyObject_CallFunctionObjArgs(fget, PyLong_FromLong(1), NULL);
+  return PyUnicode_READ_CHAR(pyr, 0);
+}
+
+static int py_peek(int sno) {
+  StreamDesc *s = YAP_GetStreamFromId(sno);
+  PyObject *fget = PyObject_GetAttrString(s->u.private_data, "peek");
+  PyObject *pyr = PyObject_CallFunctionObjArgs(fget, PyLong_FromLong(1), NULL);
+  return PyUnicode_READ_CHAR(pyr, 0);
+}
+
+static int64_t py_seek(int sno, int64_t where, int how) {
+  StreamDesc *s = YAP_GetStreamFromId(sno);
+  PyObject *fseek = PyObject_GetAttrString(s->u.private_data, "seek");
+  PyObject *pyr = PyObject_CallFunctionObjArgs(fseek, PyLong_FromLong(where),
+                                               PyLong_FromLong(how), NULL);
+  return PyLong_AsLong(pyr);
+}
+
+static void py_flush(int sno) {
+  StreamDesc *s = YAP_GetStreamFromId(sno);
+  PyObject *flush = PyObject_GetAttrString(s->u.private_data, "flush");
+  PyObject_CallFunction(flush, NULL);
+}
+
+#if 0
+static void python_output(void) {
+  PyObject *stream = string_to_python("sys.stdout", true, NULL);
+  StreamDesc *st = YAP_GetStreamFromId(1);
+  st->u.private_data = stream;
+  st->vfs = &pystream;
+  stream = string_to_python("sys.stderr", true, NULL);
+  st = YAP_GetStreamFromIds(2);
+  st->u.private_data = stream;
+  st->vfs = &pystream;
+}
+#endif
+
+static bool initialized = false;
+
+bool init_python_vfs(void) {
+  // pyw = PyUnicode_FromString("x");
+  // pyw_kind = PyUnicode_KIND(pyw);
+  // pyw_data = PyUnicode_DATA(pyw);
+  if (initialized)
+    return false;
+  initialized = true;
+  pystream.name = "python stream";
+  pystream.vflags =
+      VFS_CAN_WRITE | VFS_CAN_EXEC | VFS_CAN_READ | VFS_HAS_PREFIX;
+  pystream.prefix = "/python/";
+  pystream.suffix = NULL;
+  pystream.open = py_open;
+  pystream.close = py_close;
+  pystream.get_char = py_get;
+  pystream.peek_char = py_peek;
+  pystream.put_char = py_put;
+  pystream.flush = py_flush;
+  pystream.seek = py_seek;
+  pystream.next = GLOBAL_VFS;
+  GLOBAL_VFS = &pystream;
+  // NULL;
+  return true;
+}
diff --git a/packages/python/pypreds.c b/packages/python/pypreds.c
index 4eef7f4f2..8c609f16d 100644
--- a/packages/python/pypreds.c
+++ b/packages/python/pypreds.c
@@ -680,4 +680,6 @@ install_t install_pypreds(void) {
   PL_register_foreign("python_import", 2, python_import, 0);
   PL_register_foreign("python_access", 3, python_access, 0);
   PL_register_foreign("python_threaded", 0, p_python_threaded, 0);
+
+  init_python_vfs();
 }
diff --git a/packages/python/python.c b/packages/python/python.c
index 2b7b3603e..bcb1b53e6 100644
--- a/packages/python/python.c
+++ b/packages/python/python.c
@@ -25,130 +25,6 @@ X_API PyObject *py_Sys;
 PyObject *py_Context;
 PyObject *py_ModDict;
 
-VFS_t pystream;
-
-static void *
-py_open(VFS_t *me, int sno, const char *name,
-                     const char *io_mode) {
-#if HAVE_STRCASESTR
-  if (strcasestr(name, "/python/") == name)
-    name += strlen("/python/");
-#else
-  if (strstr(name, "/python/") == name)
-    name += strlen("/python/");
-#endif
-  StreamDesc *st = YAP_RepStreamFromId(sno);
-  fprintf(stderr,"opened %d\n", sno);
-  // we assume object is already open, so there is no need to open it.
-  PyObject *stream = string_to_python(name, true, NULL);
-  if (stream == Py_None)
-    return NULL;
-  Py_INCREF(stream);
-  st->u.private_data = stream;
-  st->vfs = me;
-  if (strchr(io_mode,'r'))
-      st->status = Input_Stream_f;
-      else
-  st->status = Append_Stream_f | Output_Stream_f;
-  Yap_DefaultStreamOps(st);
-  return stream;
-}
-
-static bool
-py_close(int sno) {
-  return true;
-  StreamDesc *s = YAP_GetStreamFromId(sno);
-  PyObject *fclose = PyObject_GetAttrString(s->u.private_data, "close");
-  PyObject *rc = PyObject_CallObject(fclose, NULL);
-  bool v = (rc == Py_True);
-  return v;
-}
-
-static int
-py_put(int sno, int ch) {
-  // PyObject *pyw; // buffer
-  // int pyw_kind;
-  // PyObject *pyw_data;
-
-  char s[2];
-  StreamDesc *st = YAP_GetStreamFromId(sno);
-  //  PyUnicode_WRITE(pyw_kind, pyw_data, 0, ch);
-  PyObject *err, *fput = PyObject_GetAttrString(st->u.private_data, "write");
-  s[0] = ch;
-  s[1] = '\0';
-  PyObject_CallFunctionObjArgs(fput, PyBytes_FromString(s), NULL);
-  if ((err = PyErr_Occurred())) {
-    PyErr_SetString(
-        err,
-        "Error in put\n"); // %s:%s:%d!\n", __FILE__, __FUNCTION__, __LINE__);
-  }
-  return ch;
-}
-
-static int py_get(int sno) {
-  StreamDesc *s = YAP_GetStreamFromId(sno);
-  PyObject *fget = PyObject_GetAttrString(s->u.private_data, "read");
-  PyObject *pyr = PyObject_CallFunctionObjArgs(fget, PyLong_FromLong(1), NULL);
-  return PyUnicode_READ_CHAR(pyr, 0);
-}
-
-static int py_peek(int sno) {
-  StreamDesc *s = YAP_GetStreamFromId(sno);
-  PyObject *fget = PyObject_GetAttrString(s->u.private_data, "peek");
-  PyObject *pyr = PyObject_CallFunctionObjArgs(fget, PyLong_FromLong(1), NULL);
-  return PyUnicode_READ_CHAR(pyr, 0);
-}
-
-static int64_t py_seek(int sno, int64_t where, int how) {
-  StreamDesc *s = YAP_GetStreamFromId(sno);
-  PyObject *fseek = PyObject_GetAttrString(s->u.private_data, "seek");
-  PyObject *pyr = PyObject_CallFunctionObjArgs(fseek, PyLong_FromLong(where),
-                                               PyLong_FromLong(how), NULL);
-  return PyLong_AsLong(pyr);
-}
-
-static void py_flush(int sno) {
-  StreamDesc *s = YAP_GetStreamFromId(sno);
-  PyObject *flush = PyObject_GetAttrString(s->u.private_data, "flush");
-  PyObject_CallFunction(flush, NULL);
-}
-
-#if 0
-static void python_output(void) {
-  PyObject *stream = string_to_python("sys.stdout", true, NULL);
-  StreamDesc *st = YAP_GetStreamFromId(1);
-  st->u.private_data = stream;
-  st->vfs = &pystream;
-  stream = string_to_python("sys.stderr", true, NULL);
-  st = YAP_GetStreamFromIds(2);
-  st->u.private_data = stream;
-  st->vfs = &pystream;
-}
-#endif
-
-static bool init_python_stream(void) {
-  // pyw = PyUnicode_FromString("x");
-  // pyw_kind = PyUnicode_KIND(pyw);
-  // pyw_data = PyUnicode_DATA(pyw);
-
-  pystream.name = "python stream";
-  pystream.vflags =
-      VFS_CAN_WRITE | VFS_CAN_EXEC | VFS_CAN_READ | VFS_HAS_PREFIX;
-  pystream.prefix = "/python/";
-  pystream.suffix = NULL;
-  pystream.open = py_open;
-  pystream.close = py_close;
-  pystream.get_char = py_get;
-  pystream.peek_char = py_peek;
-  pystream.put_char = py_put;
-  pystream.flush = py_flush;
-  pystream.seek = py_seek;
-  pystream.next = GLOBAL_VFS;
-  GLOBAL_VFS = &pystream;
-  // NULL;
-  return true;
-}
-
 X_API PyObject *Py_f2p;
 
 extern X_API bool python_in_python;
@@ -170,7 +46,7 @@ static void add_modules(void) {
   Py_f2p = PythonLookup("f2p", NULL);
   if (Py_f2p)
     Py_INCREF(Py_f2p);
-  init_python_stream();
+  init_python_vfs();
 }
 
 static void install_py_constants(void) {
diff --git a/packages/python/python.pl b/packages/python/python.pl
index 792e44279..42a2ef10d 100644
--- a/packages/python/python.pl
+++ b/packages/python/python.pl
@@ -31,11 +31,7 @@
 	   release_GIL/0,
 		 python_threaded/0,
 		 prolog_list_to_python_list/3,
-	   (:=)/2,
-	   (:=)/1,
-	%   (<-)/2,
-	%   (<-)/1,
-	   op(100,fy,$),
+		   op(100,fy,$),
 	   op(950,fy,:=),
 	   op(950,yfx,:=),
 	   op(950,fx,<-),
@@ -114,41 +110,60 @@ Data types are
 :- use_module(library(charsio)).
 :- dynamic python_mref_cache/2, python_obj_cache/2.
 
+:- multifile user:(:=)/2,
+        user:(:=)/1,
+        user:(<-)/1,
+        user:(<-)/2, user:'()'/1, user:'{}'/1, user:dot_qualified_goal/2, user:import_arg/1.
+
+
+import( F ) :- catch( python:python_import(F), _, fail ).
+
+user:dot_qualified_goal(Fs) :- catch( python:python_proc(Fs), _, fail ).
+
+user:F() :-
+	catch( python:python_proc(F() ), _, fail ).
+
+
+user(P1,P2) :- !,
+	:= P1,
+	:= P2.
+
+:= F :- catch( python:python_proc(F), _, fail ).
+
 := (P1,P2) :- !,
 	:= P1,
 	:= P2.
-:= import( F ) :- !, python_import(F).
-:= F :- python_proc(F).
 
-V <- F :-
+user:(:= ) :- catch( python:python_proc(F), _, fail ).
+
+user:( V := F ) :-
+    python:python_assign(F, V).
+
+user:(<- F) :-
+	catch( python:python_proc(F), _, fail ).
+
+user:(V <- F) :-
 	V := F.
 
-( V := F ) :-
-    python_assign(F, V).
-
-((<- F)) :-
-	:= F.
-
-python_import(Module) :-
-    python_import(Module, _).
+python:python_import(Module) :-
+    python:python_import(Module, _).
 
 
 python(Exp, Out) :-
 	Out := Exp.
 
 python_command(Cmd) :-
-       python_run_command(Cmd).
-
+       python:python_run_command(Cmd).
 
 start_python :-
-	python_import('inspect', _),
+	python:python_import('inspect', _),
 	at_halt(end_python).
 
 add_cwd_to_python :-
 	unix(getcwd(Dir)),
 	atom_concat(['sys.path.append(\"',Dir,'\")'], Command),
-	python_command(Command),
-	python_command("sys.argv = [\"yap\"]").
+	python:python_command(Command),
+	python:python_command("sys.argv = [\"yap\"]").
 	% done
 
 :- initialization( load_foreign_files(['YAPPython'], [], init_python_dll), now ).
diff --git a/packages/python/swig/prolog/yapi.yap b/packages/python/swig/prolog/yapi.yap
index bd226da15..e45c49a93 100644
--- a/packages/python/swig/prolog/yapi.yap
+++ b/packages/python/swig/prolog/yapi.yap
@@ -1,7 +1,7 @@
 %% @file yapi.yap
 %% @brief support yap shell
 %%
-:- start_low_level_trace.
+%:- start_low_level_trace.
  :- module(yapi, [
  		 python_ouput/0,
  		 show_answer/2,
@@ -60,7 +60,8 @@ argi(N,I,I1) :-
     atomic_concat(`A`,I,N),
 	I1 is I+1.
 
-python_query( Self, String ) :-
+python_query( Caller, String ) :-
+    Self := Caller.it,
  	atomic_to_term( String, Goal, VarNames ),
 	query_to_answer( Goal, VarNames, Status, Bindings),
 	Self.port := Status,
diff --git a/packages/python/swig/yap4py/yapi.py b/packages/python/swig/yap4py/yapi.py
index e3afa04fd..8ee768e91 100644
--- a/packages/python/swig/yap4py/yapi.py
+++ b/packages/python/swig/yap4py/yapi.py
@@ -18,11 +18,11 @@ class Engine( YAPEngine ):
         if self_contained:
             yap_lib_path = os.path.dirname(__file__)
             args.setYapShareDir(os.path.join(yap_lib_path, "prolog"))
-            args.setYapLibDir(yap_lib_path)
+            args.setYapPLDIR(yap_lib_path)
             args.setSavedState(os.path.join(yap_lib_path, "startup.yss"))
         YAPEngine.__init__(self, args)
         self.goal(set_prolog_flag('verbose', 'silent'))
-        self.goal(use_module(library('yapi')))
+        self.goal(compile(library('yapi')))
         self.goal(set_prolog_flag('verbose', 'normal'))
 
     def run(self, g, m=None):
@@ -49,19 +49,22 @@ class Predicate( YAPPredicate ):
 
 class Goal(object):
     """Goal is a predicate instantiated under a specific environment """
-    def __init__(self, g, engine, module="user",program=None, max_answers=None ):
-        self.g = g
+    def __init__(self, engine, g):
+        self.q = engine.query(g)
         self.e = engine
+        self.port = "call"
+        self.bindings = None
 
     def __iter__(self):
-        return PrologTableIter( self.e, self.g )
+        return PrologTableIter( self.e, self )
 
 class PrologTableIter:
 
-    def __init__(self, e, query):
+    def __init__(self, e, g):
         try:
             self.e = e
-            self.q = e.query(python_query(self, query))
+            self.g = g
+            self.q = g.q
         except:
             print('Error')
 
@@ -74,8 +77,8 @@ class PrologTableIter:
         if not self.q:
             raise StopIteration()
         if self.q.next():
-            rc = self.q.bindings
-            if self.q.port == "exit":
+            rc = self.g.bindings
+            if self.g.port == "exit":
                 self.close()
             return rc
         else:
@@ -98,7 +101,7 @@ global engine, handler
 
 yap_lib_path = os.path.dirname(__file__)
 
-use_module = namedtuple('use_module', 'file')
+compile = namedtuple('compile', 'file')
 bindvars = namedtuple('bindvars', 'list')
 library = namedtuple('library', 'list')
 v = namedtuple( 'v', 'slot')
@@ -153,7 +156,7 @@ class YAPShell:
 
 
     def query_prolog(self, engine, query):
-        import pdb; pdb.set_trace()
+        #import pdb; pdb.set_trace()
         #
         # construct a query from a one-line string
         # q is opaque to Python
@@ -174,8 +177,9 @@ class YAPShell:
         do_ask = True
         self.e = engine
         bindings = []
+        g = python_query(self, query)
         if not self.q:
-            self.it = PrologTableIter( self.e, query )
+            self.it = Goal( engine, g )
         for bind in self.it:
             bindings += [bind]
             if do_ask:
diff --git a/packages/python/yap_kernel/setup.py b/packages/python/yap_kernel/setup.py
index 1e1d49eed..5ffe87dfd 100644
--- a/packages/python/yap_kernel/setup.py
+++ b/packages/python/yap_kernel/setup.py
@@ -37,15 +37,15 @@ from distutils.core import setup
 
 pjoin = os.path.join
 here = os.path.abspath(os.path.dirname(__file__))
-packages = []
+packages = ['yap_kernel','yap_ipython']
 # pkg_root = pjoin(here, name)
 
-for d, _, _ in os.walk(pjoin(here, 'yap_kernel')):
-    if os.path.exists(pjoin(d, '__init__.py')):
-        packages.append(d[len(here)+1:].replace(os.path.sep, '.'))
-for d, _, _ in os.walk(pjoin(here, 'yap_ipython')):
-    if os.path.exists(pjoin(d, '__init__.py')):
-        packages.append(d[len(here)+1:].replace(os.path.sep, '.'))
+# for d, _, _ in os.walk(pjoin(here, 'yap_kernel')):
+#     if os.path.exists(pjoin(d, '__init__.py')):
+#         packages.append(d[len(here)+1:].replace(os.path.sep, '.'))
+# for d, _, _ in os.walk(pjoin(here, 'yap_ipython')):
+#     if os.path.exists(pjoin(d, '__init__.py')):
+#         packages.append(d[len(here)+1:].replace(os.path.sep, '.'))
 
 sys.path.insert(0, here)
 package_data = {
diff --git a/packages/python/yap_kernel/yap_ipython/core/interactiveshell.py b/packages/python/yap_kernel/yap_ipython/core/interactiveshell.py
index 1f741361d..170260c82 100644
--- a/packages/python/yap_kernel/yap_ipython/core/interactiveshell.py
+++ b/packages/python/yap_kernel/yap_ipython/core/interactiveshell.py
@@ -2324,8 +2324,8 @@ class InteractiveShell(SingletonConfigurable):
           Command to execute (can not end in '&', as background processes are
           not supported.
         split : bool, optional
-          If True, split the output into an yap_ipython SList.  Otherwise, an
-          yap_ipython LSString is returned.  These are objects similar to normal
+          If True, split the output into an IPython SList.  Otherwise, an
+          ipython LSString is returned.  These are objects similar to normal
           lists and strings, with a few convenience attributes for easier
           manipulation of line-based output.  You can use '?' on them for
           details.
@@ -2598,7 +2598,7 @@ class InteractiveShell(SingletonConfigurable):
         with prepended_to_syspath(dname):
             try:
                 for cell in get_cells():
-                    result = self.run_cell(cell, silent=True, shell_futures=shell_futures)
+                    result = self.run_cell(cell, silent=False , shell_futures=shell_futures)
                     if raise_exceptions:
                         result.raise_error()
                     elif not result.success:
diff --git a/packages/python/yap_kernel/yap_ipython/prolog/jupyter.yap b/packages/python/yap_kernel/yap_ipython/prolog/jupyter.yap
index 17a57f620..5685f68ca 100644
--- a/packages/python/yap_kernel/yap_ipython/prolog/jupyter.yap
+++ b/packages/python/yap_kernel/yap_ipython/prolog/jupyter.yap
@@ -1,3 +1,4 @@
+
 /**
  * @file jupyter.yap
  *
@@ -20,30 +21,30 @@
  %%            ).
 
 
-%:-	 reexport(library(yapi)).
+:-	 reexport(library(yapi)).
 :-	 use_module(library(lists)).
 :-	 use_module(library(maplist)).
 :-	 use_module(library(python)).
 
 :- python_import(sys).
 
-jupyter_query(Self, Cell, Line ) :-
-        start_low_level_trace,
-	setup_call_cleanup(
-			   enter_cell(Self),
-			  jupyter_cell(Self, Cell, Line),
-			   exit_cell(Self)
-	 	   ).
+jupyter_query(Caller, Cell, Line ) :-
+	jupyter_cell(Caller, Cell, Line).
 
-jupyter_cell(_Self, Cell, _) :-
+jupyter_cell(_Caller, Cell, _) :-
 	jupyter_consult(Cell),
 	fail.
-jupyter_cell( _Self, _, Line ) :-
+jupyter_cell( _Caller, _, Line ) :-
 	blank( Line ),
 	!.
-jupyter_cell( _Self, _, [] ) :- !.
-jupyter_cell( Self, _, Line ) :-
-	python_query( Self, Line ).
+jupyter_cell( _Caller, _, [] ) :- !.
+jupyter_cell( Caller, _, Line ) :-
+gated_call(
+		   enter_cell(call),
+		  python_query( Caller, Line ),
+		  Port,
+		   enter_cell(Port)
+	   ).
 
 jupyter_consult(Text) :-
 	blank( Text ),
@@ -61,18 +62,31 @@ blankc(' ').
 blankc('\n').
 blankc('\t').
 
-enter_cell(_Self) :-
-	open('/python/input', read, Input, []),
-	open('/python/sys.stdout', append, Output, []),
-	open('/python/sys.stdout', append, Error, []),
-	set_prolog_flag(user_input, Input),
-	set_prolog_flag(user_output, Output),
-	set_prolog_flag(user_error, Error).
+enter_cell(retry) :-
+	enter_cell(call).
+enter_cell(call) :-
+	into_cell.
+enter_cell(fail) :-
+	enter_cell(exit).
+enter_cell(answer) :-
+	enter_cell(exit).
+enter_cell(exception(_)) :-
+	enter_cell(exit).
+enter_cell(external_exception(_)).
+	enter_cell(!).
+enter_cell(exit) :-
+    nb_setval(jupyter_cell, off),
+	close( user_output).
 
-exit_cell(_Self) :-
-	close( user_input),
-	close( user_output),
-	close( user_error).
+
+into_cell :-
+    nb_setval(jupyter_cell, on),
+	open('/python/sys.input', read, _Input, [bom(false)]),
+    open('/python/sys.stdout', append, _Output, []),
+    open('/python/sys.stderr', append, _Error, []),
+	set_prolog_flag(user_input,_Output),
+	set_prolog_flag(user_output,_Output),
+    set_prolog_flag(user_error,_Error).
 
 
 completions(S, Self) :-
@@ -188,14 +202,14 @@ errors( Self, Text ) :-
        			   close_events( Self )
        	 	   ).
 
-clauses(Self, Stream) :-
+clauses(_Self, Stream) :-
     repeat,
     read_clause(Stream, Cl, [term_position(_Pos), syntax_errors(fail)] ),
 %	command( Self, Cl ),
     Cl == end_of_file,
     !.
 
-goals(Self, Stream) :-
+goals(_Self, Stream) :-
     repeat,
     read_term(Stream, Cl, [term_position(_Pos), syntax_errors(fail)] ),
 %	command( Self, Cl ),
@@ -252,14 +266,14 @@ user:portray_message(_Severity, error(syntax_error(Cause),info(between(_,LN,_),
         assert( syntax_error(Cause,LN,CharPos,Details) ).
 user:portray_message(_Severity, error(style_check(_),_) ) :-
 	nb_getval(jupyter_cell, on).
-      
+
 open_events(Self, Text, Stream) :-
 	Self.errors := [],
 	nb_setval( jupyter, on),
     open_mem_read_stream( Text, Stream ).
 
 :- initialization( nb_setval( jupyter, off ) ).
-		     
+
 close_events( _Self ) :-
 	nb_setval( jupyter, off ),
 	retract( undo(G) ),
@@ -271,4 +285,4 @@ close_events( Self ) :-
     fail.
 close_events( _ ).
 
-:- ( start_low_level_trace ).
+%:- ( start_low_level_trace ).
diff --git a/packages/python/yap_kernel/yap_ipython/yapi.py b/packages/python/yap_kernel/yap_ipython/yapi.py
index c355f8c9c..fdc8c0957 100644
--- a/packages/python/yap_kernel/yap_ipython/yapi.py
+++ b/packages/python/yap_kernel/yap_ipython/yapi.py
@@ -9,20 +9,21 @@ from typing import Iterator, List, Tuple, Iterable, Union
 from traitlets import Bool, Enum, observe, Int
 
 try:
-    from yap4py.yapi import Engine
+    from yap4py.yapi import Engine, Goal, EngineArgs, PrologTableIter
 except:
     print("Could not load _yap dll.")
-from yap_ipython.core import interactiveshell
 from yap_ipython.core.completer import Completer, Completion
 from yap_ipython.utils.strdispatch import StrDispatch
 # import yap_ipython.core
 from traitlets import Instance
 from yap_ipython.core.inputsplitter import *
 from yap_ipython.core.inputtransformer import *
+from yap_ipython.core.interactiveshell import *
 from pygments import highlight
 from pygments.lexers.prolog import PrologLexer
 from pygments.formatters import HtmlFormatter
 
+from yap_ipython.core import interactiveshell
 
 from collections import namedtuple
 
@@ -106,7 +107,6 @@ class YAPInputSplitter(InputSplitter):
     def validQuery(self, text, line=None):
         """Return whether a legal query
         """
-        print("valid")
         if not  line:
             (_,line,_) = self.shell.prolog_cell(text)
         line = line.strip().rstrip()
@@ -114,7 +114,6 @@ class YAPInputSplitter(InputSplitter):
             return False
         self.errors = []
         self.yapeng.mgoal(errors(self, line),"user")
-        print(self.errors)
         return self.errors != []
 
 
@@ -279,7 +278,7 @@ class YAPCompleter(Completer):
                   help="""Activate greedy completion
         PENDING DEPRECTION. this is now mostly taken care of with Jedi.
 
-        This will enable completion on elements of lists, results of function calls, etc.,
+        This will enable completion on elements of lists, self.results of function calls, etc.,
         but can be unsafe because the code is actually evaluated on TAB.
         """
                   ).tag(config=True)
@@ -511,8 +510,9 @@ class YAPRun:
         self.yapeng = Engine()
         self.yapeng.goal(use_module(library("jupyter")))
         self.q = None
-        self.run = False
-        self.shell.port = None
+        self.port = "call"
+        self.os = None
+        self.it = None
         self.shell.yapeng = self.yapeng
         self._get_exc_info = shell._get_exc_info
 
@@ -525,27 +525,37 @@ class YAPRun:
         self.yapeng.mgoal(errors(self,text),"user")
         return self.errors
 
-    def jupyter_query(self, s, mx):
+    def jupyter_query(self, s):
         #
         # construct a self.query from a one-line string
         # self.q is opaque to Python
-        iterations = 0
-        bindings = []
-        program,query,_ = self.prolog_cell(s)
-        if query == self.shell.os:
-            q = self.shell.q
-            self.shell.os = None
+        program,query,mx = self.prolog_cell(s)
+        Found = False
+
+        if query != self.os:
+            self.os = None
+            self.iterations = 0
+            pg = jupyter_query( self, program, query)
+            self.it = Goal( self.yapeng,  pg)
         else:
-            q = Goal(jupyter_query(self, query), self.yapeng, module="user",program=program)
-        for q in q:
-            bindings += [q.bindings()]
-            iterations += 1
-            if mx == iterations:
-                break
-        if q:
-            self.shell.os = query
-        self.shell.q = q
-        return bindings
+            mx += self.iterations
+            self.os = s
+        for answ in self.it:
+            found = True
+            self.bindings += [answ]
+            self.iterations += 1
+            if mx == self.iterations:
+                return True, self.bindings
+        port = self.it.port
+        if port == "exit":
+            self.q = None
+            self.os = None
+            return True,self.bindings
+        if port == "fail":
+            self.q = none
+            self.os = None
+            if self.bindings_message:
+                return True,self.bindings
 
 
     def _yrun_cell(self, raw_cell, store_history=True, silent=False,
@@ -563,7 +573,7 @@ class YAPRun:
                    IPython's machinery, this
                    should be set to False.
                    silent : bool
-          If True, avoid side-effects, such as implicit displayhooks and
+v          If True, avoid side-effects, such as implicit displayhooks and
                    and logging.  silent=True forces store_history=False.
                    shell_futures : bool
           If True, the code will share future statements with the interactive
@@ -576,7 +586,7 @@ class YAPRun:
 
                    -------
 
-`result : :class:`ExecutionResult`
+`self.result : :class:`Executionself.result`
                    """
 
         # construct a query from a one-line string
@@ -594,22 +604,22 @@ class YAPRun:
         info = interactiveshell.ExecutionInfo(
             raw_cell, store_history, silent, shell_futures)
 
-        result = interactiveshell.ExecutionResult(info)
+        self.result = interactiveshell.ExecutionResult(info)
 
         if (raw_cell == "") or raw_cell.isspace():
             self.shell.last_execution_succeeded = True
-            return result
+            return self.result
 
         if silent:
             store_history = False
 
         if store_history:
-            result.execution_count = self.shell.execution_count+1
+            self.result   .execution_count = self.shell.execution_count+1
 
         def error_before_exec(value):
-            result.error_before_exec = value
+            self.result   .error_before_exec = value
             self.shell.last_execution_succeeded = False
-            return result
+            return self.result
 
         self.shell.events.trigger('pre_execute')
         if not silent:
@@ -646,12 +656,10 @@ class YAPRun:
             except SyntaxError:
                 self.shell.showsyntaxerror(  )
                 preprocessing_exc_tuple = sys.exc_info()
-
         # Store raw and processed history
         if store_history:
             self.shell.history_manager.store_inputs(self.shell.execution_count,
                                               cell, raw_cell)
-        silent = False
         if not silent:
             self.shell.logger.log(cell, raw_cell)
         # # Display the exception if input processing failed.
@@ -681,32 +689,33 @@ class YAPRun:
                 line = txt[1]
             else:
                 line = ""
+            if len(txt0) == 2:
+                cell = txt0[1]
+            else:
+                cell = ""
             if linec:
                 self.shell.run_line_magic(magic, line)
-                if len(txt0) == 2:
-                    cell = txt0[1]
-                else:
-                    cellArea = ""
             else:
                 self.shell.run_cell_magic(magic, line, cell)
-                return
+                cell = ""
         # Give the displayhook a reference to our ExecutionResult so it
         # can fill in the output value.
-        self.shell.displayhook.exec_result = result
+        self.shell.displayhook.exec_result = self.result
         has_raised = False
         try:
+            state = None
             self.shell.bindings = dict = {}
-            state = self.jupyter_query( cell)
+            if cell.strip():
+                state = self.jupyter_query( cell )
             if state:
                 self.shell.last_execution_succeeded = True
-                result.result = (True, dict)
+                self.result.result    = (True, dict)
             else:
                 self.shell.last_execution_succeeded = True
-                result.result = (True, {})
+                self.result.result = (True, {})
         except Exception as e:
-            print(e)
             has_raised = True
-            result.result = False
+            self.result.result = False
 
         self.shell.last_execution_succeeded = not has_raised
 
@@ -724,10 +733,10 @@ class YAPRun:
             # Each cell is a *single* input, regardless of how many lines it has
             self.shell.execution_count += 1
 
-        return result
+        return self.result
 
     def    prolog_cell(self,s):
-        """"
+        """
         Trasform a text into program+query. A query is the
         last line if the last line is non-empty and does not terminate
         on a dot. You can also finish with
diff --git a/pl/CMakeLists.txt b/pl/CMakeLists.txt
index 14e71a8c1..d7a5636f8 100644
--- a/pl/CMakeLists.txt
+++ b/pl/CMakeLists.txt
@@ -56,6 +56,7 @@ set(PL_BOOT_SOURCES
         undefined.yap
         utils.yap
         yapor.yap
+        ypp.yap
         )
 
 add_to_group(PL_BOOT_SOURCES pl_boot_library)
@@ -91,8 +92,5 @@ endif()
 
 
 install(FILES ${PL_BOOT_SOURCES}
-        DESTINATION ${libpl}/pl
-        )
-install(FILES ../library/ypp.yap
-        DESTINATION ${libpl}/library
+        DESTINATION ${libpl}/pll
         )
diff --git a/pl/boot.yap b/pl/boot.yap
index 861ceda6a..d6286f335 100644
--- a/pl/boot.yap
+++ b/pl/boot.yap
@@ -109,65 +109,6 @@ private(_).
 
 % be careful here not to generate an undefined exception..
 
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
 print_message(L,E) :-
 	'$number_of_clauses'(print_message(L,E), prolog_complete, 1),
 	!,
@@ -326,7 +267,7 @@ initialize_prolog :-
 :- [
     % lists is often used.
    	 '../os/yio.yap',
-	 '../pl/debug.yap',
+	 'debug.yap',
 	 'checker.yap',
 	 'depth_bound.yap',
 	 'ground.yap',
@@ -418,7 +359,7 @@ sub-goal  _NG_ will replace  _G_ and will be processed in the same
 :- use_module('corout.yap').
 :- use_module('dialect.yap').
 :- use_module('dbload.yap').
-:- use_module('../library/ypp.yap').
+:- use_module('ypp.yap').
 :- use_module('../os/chartypes.yap').
 :- ensure_loaded('../os/edio.yap').
 
diff --git a/pl/consult.yap b/pl/consult.yap
index 87b52dcfe..fb67853a6 100644
--- a/pl/consult.yap
+++ b/pl/consult.yap
@@ -1,4 +1,4 @@
-/*************************************************************************
+s444444444444444444444444444444444444444444444444444444444444444444444444/*************************************************************************
 *									 *
   *	 YAP Prolog  							 *
 *									 *
@@ -650,12 +650,17 @@ db_files(Fs) :-
 	'$load_files'(Fs, [consult(db), if(not_loaded)], exo_files(Fs)).
 
 
+'$csult'(Fs, M) :-
+	 '$skip_list'(_, Fs ,L),
+	 L \== [],
+	 user:dot_qualified_goal(Fs),
+	 !.
 '$csult'(Fs, M) :-
 	'$extract_minus'(Fs, MFs), !,
 	'$load_files'(M:MFs,[],[M:Fs]).
 '$csult'(Fs, M) :-
 	'$load_files'(M:Fs,[consult(consult)],[M:Fs]).
-
+	
 '$extract_minus'([], []).
 '$extract_minus'([-F|Fs], [F|MFs]) :-
 	'$extract_minus'(Fs, MFs).
@@ -1627,6 +1632,8 @@ End of conditional compilation.
 
 consult_depth(LV) :- '$show_consult_level'(LV).
 
+:- '$add_multifile'(Name,Arity,Module).
+
 /**
   @}
 
diff --git a/pl/control.yap b/pl/control.yap
index 3e91343b5..fa38c654b 100644
--- a/pl/control.yap
+++ b/pl/control.yap
@@ -429,7 +429,7 @@ query_to_answer(G, V, Status, Bindings) :-
       '$answer'( answer, LGs, Vs, Bindings) :-
           !,
           '$process_answer'(Vs, LGs, Bindings).
-'$answer'(cut, _, _, _).
+'$answer'(!, _, _, _).
 '$answer'(fail,_,_,_).
 '$answer'(exception(E),_,_,_) :-
         '$LoopError'(E,error).
diff --git a/pl/debug.yap b/pl/debug.yap
index cb6bebcf0..d9614e38c 100644
--- a/pl/debug.yap
+++ b/pl/debug.yap
@@ -469,7 +469,7 @@ be lost.
 	 Border < GoalNumber,
 	 ( Spy == ignore ; '$pred_being_spied'(G, M) )
 	),
-	writeln(go:G:M),
+	%writeln(go:G:M),
 	!,
 	'$execute_nonstop'(G,M).
 '$trace_goal'(G, M, GoalNumber, H) :-
diff --git a/pl/directives.yap b/pl/directives.yap
index f54db8cc4..64cd8d9e0 100644
--- a/pl/directives.yap
+++ b/pl/directives.yap
@@ -238,7 +238,7 @@ user_defined_directive(Dir,Action) :-
 
 '$thread_initialization'(M:D) :-
 	eraseall('$thread_initialization'),
-	writeln(M:D),
+	%writeln(M:D),
 	recorda('$thread_initialization',M:D,_),
 	fail.
 '$thread_initialization'(M:D) :-
diff --git a/pl/modules.yap b/pl/modules.yap
index 45f4c5314..aaeab21f2 100644
--- a/pl/modules.yap
+++ b/pl/modules.yap
@@ -365,7 +365,6 @@ system_module(Mod) :-
 	functor(G0, N, K),
 	'$autoloader_find_predicate'(G0,ExportingMod),
 	ExportingMod \= ImportingMod,
-    writeln((ExportingMod,ImportingMod,G0,G0, N  ,K)),
     (recordzifnot('$import','$import'(ExportingMod,ImportingMod,G0,G0, N  ,K),_) -> true ; true ).
 
 
@@ -399,7 +398,7 @@ be associated to a new file.
 */
 
 '$declare_module'(Name, _Super, Context, _File, _Line) :-
-	add_import_module(Name, Context, start).
+	addi_mport_module(Name, Context, start).
 
 /**
  @pred abolish_module( + Mod) is det
@@ -492,11 +491,9 @@ export_list(Module, List) :-
 	G1=..[N1|Args],
 	( '$check_import'(M0,ContextMod,N1,K) ->
 	  ( ContextMod == prolog ->
-	   writeln((M0,ContextMod,G0,G1,N1,K)),
       recordzifnot('$import','$import'(M0,user,G0,G1,N1,K),_),
         fail
 	  ;
-    writeln((M0,ContextMod,G0,G1,N1,K)),
 	    recordaifnot('$import','$import'(M0,ContextMod,G0,G1,N1,K),_),
         fail
         ;
diff --git a/library/ypp.yap b/pl/ypp.yap
similarity index 100%
rename from library/ypp.yap
rename to pl/ypp.yap