diff --git a/actios.cpp b/actios.cpp
index babdfd0..bcc233b 100644
--- a/actios.cpp
+++ b/actios.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #include "stdafx.h"
 #include "iafx.h"
diff --git a/actios.h b/actios.h
index 3d67ba6..fc07718 100644
--- a/actios.h
+++ b/actios.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _ACTIOS_H_
 #define _ACTIOS_H_
diff --git a/argali.cpp b/argali.cpp
index 11bea69..2803fc1 100644
--- a/argali.cpp
+++ b/argali.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #include "stdafx.h"
 #include "defsys.h"
diff --git a/argali.h b/argali.h
index d801bdb..f5c2b78 100644
--- a/argali.h
+++ b/argali.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _ARGALI_H_
 #define _ARGALI_H_
diff --git a/aritval.h b/aritval.h
index 96b2cbf..6e365d7 100644
--- a/aritval.h
+++ b/aritval.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,6 +19,7 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
+
 #ifndef _ARITVAL_H_
 #define _ARITVAL_H_
 
diff --git a/binlib.cpp b/binlib.cpp
index 2f35e2e..e2db60f 100644
--- a/binlib.cpp
+++ b/binlib.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 ///////////////////////
 // binary library data
diff --git a/binlib.h b/binlib.h
index 861501b..288bfd5 100644
--- a/binlib.h
+++ b/binlib.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _BINLIB_H_
 #define _BINLIB_H_
diff --git a/binstr.cpp b/binstr.cpp
index 7a81190..9c0a5ca 100644
--- a/binstr.cpp
+++ b/binstr.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #include "stdafx.h"
 #include "binstr.h"
diff --git a/binstr.h b/binstr.h
index ff139d8..0be59f1 100644
--- a/binstr.h
+++ b/binstr.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _BINSTR_H_
 #define _BINSTR_H_
diff --git a/btarit.cpp b/btarit.cpp
index f629f4b..207dd77 100644
--- a/btarit.cpp
+++ b/btarit.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 //---------------------
 // arithmetic builtins
diff --git a/btclass.cpp b/btclass.cpp
index 8badc0d..f7cf461 100644
--- a/btclass.cpp
+++ b/btclass.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 //------------------------------
 // term classification builtins
diff --git a/btcmp.cpp b/btcmp.cpp
index e74985a..29c2ebe 100644
--- a/btcmp.cpp
+++ b/btcmp.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 //---------------------
 // comparison builtins
diff --git a/btdb.cpp b/btdb.cpp
index bad9363..eaa7c5c 100644
--- a/btdb.cpp
+++ b/btdb.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 //--------------------
 // database interface
diff --git a/bterr.h b/bterr.h
index 9766123..dca9afe 100644
--- a/bterr.h
+++ b/bterr.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #define BTERR_REQ_INT_ARG		100
 #define BTERR_NOT_VALID_VAR		101
diff --git a/btexec.cpp b/btexec.cpp
index 7227bef..350925b 100644
--- a/btexec.cpp
+++ b/btexec.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 //-------------------
 // execution control
diff --git a/btil.cpp b/btil.cpp
index a65eb11..109c6d8 100644
--- a/btil.cpp
+++ b/btil.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 ////////////////////////////////////////////////////
 // my engine object model
diff --git a/btil.h b/btil.h
index 6d7148a..aeee9e8 100644
--- a/btil.h
+++ b/btil.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _BTIL_H_
 #define _BTIL_H_
diff --git a/btio.cpp b/btio.cpp
index 6267a3a..0fbd6a9 100644
--- a/btio.cpp
+++ b/btio.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 //-----------------------
 // IO oriented operation
diff --git a/btmath.cpp b/btmath.cpp
index a7d49b1..7172627 100644
--- a/btmath.cpp
+++ b/btmath.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 //--------------
 // math builtins
diff --git a/btmeta.cpp b/btmeta.cpp
index 483b38c..ab4516a 100644
--- a/btmeta.cpp
+++ b/btmeta.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 ////////////////////////
 // metalogical builtins
diff --git a/btmix.cpp b/btmix.cpp
index c0515af..e0e0819 100644
--- a/btmix.cpp
+++ b/btmix.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 ///////////////////////////////
 // mixing of useful predicates
diff --git a/btmix.h b/btmix.h
index 223518f..7415dce 100644
--- a/btmix.h
+++ b/btmix.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _BTMIX_H_
 #define _BTMIX_H_
@@ -59,8 +56,8 @@ inline mtime::mtime(time_t t)
 }
 inline void mtime::show(ostream &s) const
 {
-	char buf[100];
-	s << format(buf, 100);
+	char buf[1<<10];
+	s << format(buf, sizeof buf);
 }
 inline int mtime::copy_able() const
 {
diff --git a/btswi0.cpp b/btswi0.cpp
new file mode 100644
index 0000000..da7d31c
--- /dev/null
+++ b/btswi0.cpp
@@ -0,0 +1,58 @@
+
+/*
+    IL : Intlog Language
+    Object Oriented Prolog Project
+    Copyright (C) 1992-2016 - Ing. Capelli Carlo
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+*/
+
+
+#include "stdafx.h"
+#include "btswi0.h"
+#include "qdata.h"
+
+#include <dirent.h>
+#include <stdio.h>
+
+BtFDecl(cd);
+BtFDecl(ls);
+BtFDecl(pwd);
+
+BuiltIn btswi0[3] = {
+    {"cd",  0,   cd},
+//    {"cd",  1,   cd},
+    {"ls",  0,   ls},
+    {"pwd", 0,   pwd},
+};
+
+BtFImpl(cd, t, p) {
+    //if (t.getarg(0))
+        //;
+    return 0;
+}
+BtFImpl_P1(ls, p) {
+    if (DIR *d = opendir(".")) {
+        struct dirent *dir;
+        while ((dir = readdir(d)) != nullptr)
+            p->out() << dir->d_name << endl;
+        closedir(d);
+        return 1;
+    }
+    return 0;
+}
+BtFImpl_P1(pwd, p) {
+    return 0;
+}
diff --git a/btswi0.h b/btswi0.h
new file mode 100644
index 0000000..28d9c11
--- /dev/null
+++ b/btswi0.h
@@ -0,0 +1,29 @@
+
+/*
+    IL : Intlog Language
+    Object Oriented Prolog Project
+    Copyright (C) 1992-2016 - Ing. Capelli Carlo
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+*/
+
+
+#ifndef BTSWI0_H
+#define BTSWI0_H
+
+#include "builtin.h"
+extern BuiltIn btswi0[3];
+
+#endif // BTSWI0_H
diff --git a/bttrace.cpp b/bttrace.cpp
index a891878..6098eaf 100644
--- a/bttrace.cpp
+++ b/bttrace.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #include "stdafx.h"
 #include "defsys.h"
diff --git a/builtin.cpp b/builtin.cpp
index fda9e2a..ebeb50c 100644
--- a/builtin.cpp
+++ b/builtin.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #include "stdafx.h"
 #include "builtin.h"
@@ -31,6 +28,8 @@
 #include "bterr.h"
 #include "dbintlog.h"
 
+#include "btswi0.h"
+
 /////////////////////////////////////////
 // standard Edinburgh builtin predicates
 /////////////////////////////////////////
@@ -135,4 +134,6 @@ void BuiltIn::Initialize(DbIntlog* pDB, MsgTable *msg)
 	addt(mixing);
 	addt(interface_obj);
 	addt(mathfunctions);
+
+    addt(btswi0);
 }
diff --git a/builtin.h b/builtin.h
index 89b8884..3c84410 100644
--- a/builtin.h
+++ b/builtin.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _BUILTIN_H_
 #define _BUILTIN_H_
diff --git a/chkrel.h b/chkrel.h
index 7e01768..454143a 100644
--- a/chkrel.h
+++ b/chkrel.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,6 +19,7 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
+
 #define RELEASE_LEVEL	9
 #define DEMO_LEVEL		1
 #define EXPERT_LEVEL	2
diff --git a/clause.cpp b/clause.cpp
index c23d22a..9450168 100644
--- a/clause.cpp
+++ b/clause.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 #include "stdafx.h"
 #include "query.h"
diff --git a/clause.h b/clause.h
index 08bf2a3..6f16637 100644
--- a/clause.h
+++ b/clause.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _CLAUSE_H_
 #define _CLAUSE_H_
diff --git a/constr.cpp b/constr.cpp
index b5cdbd5..8c00bb4 100644
--- a/constr.cpp
+++ b/constr.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,6 +19,7 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
+
 #include "stdafx.h"
 #include "iafx.h"
 #include "constr.h"
diff --git a/constr.h b/constr.h
index 0f5f546..021738a 100644
--- a/constr.h
+++ b/constr.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,6 +19,7 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
+
 #ifndef _CONSTR_H_
 #define _CONSTR_H_
 
diff --git a/dbdisp.cpp b/dbdisp.cpp
index 730b3a8..702aa4e 100644
--- a/dbdisp.cpp
+++ b/dbdisp.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 ///////////////////////////
 // IntLog database Display
diff --git a/dbintlog.cpp b/dbintlog.cpp
index 35eeeaf..4854b50 100644
--- a/dbintlog.cpp
+++ b/dbintlog.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 ///////////////////
 // IntLog database
diff --git a/dbintlog.h b/dbintlog.h
index ebc3d4a..7b693ee 100644
--- a/dbintlog.h
+++ b/dbintlog.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _DBINTLOG_H_
 #define _DBINTLOG_H_
diff --git a/defsys.cpp b/defsys.cpp
index 9906c93..a6c93ca 100644
--- a/defsys.cpp
+++ b/defsys.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 //-----------------------
 // default messages/data
diff --git a/defsys.h b/defsys.h
index 142297c..a1c753e 100644
--- a/defsys.h
+++ b/defsys.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _DEFSYS_H_
 #define _DEFSYS_H_
diff --git a/dlist.h b/dlist.h
index a2ab1b9..4616f3c 100644
--- a/dlist.h
+++ b/dlist.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _DLIST_H_
 #define _DLIST_H_
diff --git a/eng.cpp b/eng.cpp
index b0f9edd..f34b619 100644
--- a/eng.cpp
+++ b/eng.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 /////////////////////////////////////
 // engine objects mapped to handlers
diff --git a/eng.h b/eng.h
index 0fc41fb..137c3f5 100644
--- a/eng.h
+++ b/eng.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _ENG_H_
 #define _ENG_H_
diff --git a/fastree.cpp b/fastree.cpp
index bef1be8..f3131ff 100644
--- a/fastree.cpp
+++ b/fastree.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,6 +19,7 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
+
 #include "stdafx.h"
 #include "fastree.h"
 #include <iomanip>
diff --git a/fastree.h b/fastree.h
index 39efd86..b17099d 100644
--- a/fastree.h
+++ b/fastree.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,6 +19,7 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
+
 #ifndef _FASTREE_H_
 #define _FASTREE_H_
 
diff --git a/findall.cpp b/findall.cpp
index 2086fcc..1a0a510 100644
--- a/findall.cpp
+++ b/findall.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #include "stdafx.h"
 #include "qdata.h"
diff --git a/hasht.cpp b/hasht.cpp
index 6199eb2..49d6f2f 100644
--- a/hasht.cpp
+++ b/hasht.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 //--------------------
 // resizing hashtable
diff --git a/hasht.h b/hasht.h
index e73621f..ddc19e2 100644
--- a/hasht.h
+++ b/hasht.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _HASHT_H_
 #define _HASHT_H_
diff --git a/iafx.cpp b/iafx.cpp
index 65ad6d2..f5ee2cf 100644
--- a/iafx.cpp
+++ b/iafx.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #include "stdafx.h"
 #include <sstream>
diff --git a/iafx.h b/iafx.h
index 31e9810..e3a9f66 100644
--- a/iafx.h
+++ b/iafx.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _IAFX_H_
 #define _IAFX_H_
diff --git a/iostreams_qt/iostreams_qt.pro b/iostreams_qt/iostreams_qt.pro
index 5d888dc..32b4aa6 100644
--- a/iostreams_qt/iostreams_qt.pro
+++ b/iostreams_qt/iostreams_qt.pro
@@ -74,7 +74,8 @@ SOURCES += \
     ../argali.cpp \
     ../actios.cpp \
     text_widget.cpp \
-    main_window.cpp
+    main_window.cpp \
+    ../btswi0.cpp
 
 OTHER_FILES += \
     ../README.md
@@ -125,4 +126,5 @@ HEADERS += \
     ../argali.h \
     ../actios.h \
     text_widget.h \
-    main_window.h
+    main_window.h \
+    ../btswi0.h
diff --git a/kstr.cpp b/kstr.cpp
index c4c7702..826083a 100644
--- a/kstr.cpp
+++ b/kstr.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 //-----------------
 // string storage
diff --git a/kstr.h b/kstr.h
index a89c485..906c3e5 100644
--- a/kstr.h
+++ b/kstr.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _KSTR_H_
 #define _KSTR_H_
diff --git a/membuf.h b/membuf.h
index f79b3b7..55a713f 100644
--- a/membuf.h
+++ b/membuf.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,12 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
+
 #ifndef _MEMBUF_H_
 #define _MEMBUF_H_
 
 // in-memory files support
-// 
+//
 struct IAFX_API membuf : public e_slist {
     kstring id;
     char *mem;
diff --git a/memstore.h b/memstore.h
index f5f58b9..40508ff 100644
--- a/memstore.h
+++ b/memstore.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _MEMSTORE_H_
 #define _MEMSTORE_H_
diff --git a/message.cpp b/message.cpp
index 0fbfc08..8d939f8 100644
--- a/message.cpp
+++ b/message.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #include "stdafx.h"
 #include "message.h"
diff --git a/message.h b/message.h
index d21fa10..573f022 100644
--- a/message.h
+++ b/message.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _MESSAGE_H_
 #define _MESSAGE_H_
diff --git a/mycont.h b/mycont.h
index b995e47..d3d72a1 100644
--- a/mycont.h
+++ b/mycont.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _MYCONT_H_
 #define _MYCONT_H_
diff --git a/operator.cpp b/operator.cpp
index df648b7..03af3eb 100644
--- a/operator.cpp
+++ b/operator.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 ////////////////////////////
 // operator table handling
diff --git a/operator.h b/operator.h
index e2cd20d..9b21547 100644
--- a/operator.h
+++ b/operator.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _OPERATOR_H_
 #define _OPERATOR_H_
diff --git a/parse.cpp b/parse.cpp
index 3bdec9f..be6f735 100644
--- a/parse.cpp
+++ b/parse.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 //------------------------------------------------------
 // parse required file (recursive descendent algorithm)
diff --git a/parse.h b/parse.h
index 0835fa8..34568b4 100644
--- a/parse.h
+++ b/parse.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _PARSE_H_
 #define _PARSE_H_
diff --git a/parsemsg.h b/parsemsg.h
index e4741ee..0c51f82 100644
--- a/parsemsg.h
+++ b/parsemsg.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 // parser error codes
 #define FILE_NOT_FOUND			0
diff --git a/proios.cpp b/proios.cpp
index d92de73..4673230 100644
--- a/proios.cpp
+++ b/proios.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 ///////////////////////////////
 // modelling Intlog IO streams
diff --git a/proios.h b/proios.h
index 8c1f05e..e1df7ce 100644
--- a/proios.h
+++ b/proios.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _PROIOS_H_
 #define _PROIOS_H_
diff --git a/qdata.cpp b/qdata.cpp
index 33ff5aa..cd61233 100644
--- a/qdata.cpp
+++ b/qdata.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 ///////////////////////
 // query data access
diff --git a/qdata.h b/qdata.h
index 8f905e9..6286f41 100644
--- a/qdata.h
+++ b/qdata.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _QDATA_H_
 #define _QDATA_H_
diff --git a/qstack.cpp b/qstack.cpp
index a167568..bf5cf9d 100644
--- a/qstack.cpp
+++ b/qstack.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 //-------------------------
 // query evaluation stacks
diff --git a/query.cpp b/query.cpp
index 0069962..aab8780 100644
--- a/query.cpp
+++ b/query.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 //-------------------------
 // IntlogExec query engine
diff --git a/query.h b/query.h
index 41f81fd..09c82c0 100644
--- a/query.h
+++ b/query.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-    Intlog Language
-    Object Oriented Prolog Project
-    Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _QUERY_H_
 #define _QUERY_H_
diff --git a/reduce.cpp b/reduce.cpp
index 7950ecd..0d43098 100644
--- a/reduce.cpp
+++ b/reduce.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 //-------------------------
 // term parsing reduction
diff --git a/reduce.h b/reduce.h
index 2c19c96..b3f785b 100644
--- a/reduce.h
+++ b/reduce.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _REDUCE_H_
 #define _REDUCE_H_
diff --git a/scanner.cpp b/scanner.cpp
index 4b1a66d..8dea7de 100644
--- a/scanner.cpp
+++ b/scanner.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,13 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-
-	intlog tokens scanner
-*/
 
 #include "stdafx.h"
 #include "defsys.h"
diff --git a/scanner.h b/scanner.h
index 222643a..ef905b2 100644
--- a/scanner.h
+++ b/scanner.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _SCANNER_H_
 #define _SCANNER_H_
diff --git a/slist.cpp b/slist.cpp
index 9af1f58..828cf10 100644
--- a/slist.cpp
+++ b/slist.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 //--------------------
 // single linked list
diff --git a/slist.h b/slist.h
index 4c6d5bf..ced0176 100644
--- a/slist.h
+++ b/slist.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _SLIST_H_
 #define _SLIST_H_
diff --git a/srcpos.h b/srcpos.h
index 08e6c2b..176564d 100644
--- a/srcpos.h
+++ b/srcpos.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,6 +19,7 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
+
 #ifndef _SRCPOS_H_
 #define _SRCPOS_H_
 
diff --git a/stack.h b/stack.h
index c17b4a5..2460278 100644
--- a/stack.h
+++ b/stack.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _STACK_H_
 #define _STACK_H_
diff --git a/stdafx.h b/stdafx.h
index c635ae7..5b3f6b3 100644
--- a/stdafx.h
+++ b/stdafx.h
@@ -1,7 +1,8 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
-    2011 - Ported to Qt 4.7
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -18,6 +19,7 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
+
 #include <stdlib.h>
 #include <string.h>
 #include <iostream>
diff --git a/strftime.cpp b/strftime.cpp
index e6ea3f6..e046e70 100644
--- a/strftime.cpp
+++ b/strftime.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,6 +19,7 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
+
 #include "stdafx.h"
 #include <time.h>
 #include <sstream>
diff --git a/syntaxcolor.h b/syntaxcolor.h
index f3b161e..079bcbc 100644
--- a/syntaxcolor.h
+++ b/syntaxcolor.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,6 +19,7 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
+
 #ifndef _SyntaxColor_h_
 #define _SyntaxColor_h_
 
diff --git a/sysdata.cpp b/sysdata.cpp
index bdf75fd..8d3afe7 100644
--- a/sysdata.cpp
+++ b/sysdata.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #include "stdafx.h"
 #include "defsys.h"
diff --git a/term.cpp b/term.cpp
index 9045e7f..402b28a 100644
--- a/term.cpp
+++ b/term.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 //-----------------
 // term operations
@@ -544,5 +541,6 @@ inline Term TermArgs::getarg(int n) const
 	counter++;
 	ASSERT(n >= 0 && n < arity);
 #endif
-	return args[n];
+
+	return args ? args[n] : Term(f_NOTERM);
 }
diff --git a/term.h b/term.h
index 6cbb45b..9866c04 100644
--- a/term.h
+++ b/term.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _TERM_H_
 #define _TERM_H_
diff --git a/tracer.cpp b/tracer.cpp
index 110d885..47224b0 100644
--- a/tracer.cpp
+++ b/tracer.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 //---------------------------
 // trace/spy model interface
diff --git a/tracer.h b/tracer.h
index 4e7cd22..538cec2 100644
--- a/tracer.h
+++ b/tracer.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _TRACER_H_
 #define _TRACER_H_
diff --git a/unify.cpp b/unify.cpp
index 844f232..465bef7 100644
--- a/unify.cpp
+++ b/unify.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #include "stdafx.h"
 #include "qdata.h"
diff --git a/unify.h b/unify.h
index 8e79fae..0308c60 100644
--- a/unify.h
+++ b/unify.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _UNIFY_H_
 #define _UNIFY_H_
diff --git a/vectb.h b/vectb.h
index 3d61b81..cb28094 100644
--- a/vectb.h
+++ b/vectb.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
- Intlog Language
- Object Oriented Prolog Project
- Ing. Capelli Carlo - Brescia
-*/
 
 #ifndef _VECTB_H_
 #define _VECTB_H_
diff --git a/waittask.cpp b/waittask.cpp
index 2edb496..0204386 100644
--- a/waittask.cpp
+++ b/waittask.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,6 +19,7 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
+
 #include "stdafx.h"
 
 bool WaitTaskExecution(UINT /*ntc*/)
diff --git a/write.cpp b/write.cpp
index 8b197bf..4b95abc 100644
--- a/write.cpp
+++ b/write.cpp
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,11 +19,6 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
-/*
-	Intlog Language
-	Object Oriented Prolog Project
-	Ing. Capelli Carlo - Brescia
-*/
 
 #include "stdafx.h"
 #include "qdata.h"
diff --git a/xtrace.h b/xtrace.h
index 05bbe69..6f08a3f 100644
--- a/xtrace.h
+++ b/xtrace.h
@@ -1,5 +1,7 @@
+
 /*
-    IL : Prolog interpreter
+    IL : Intlog Language
+    Object Oriented Prolog Project
     Copyright (C) 1992-2016 - Ing. Capelli Carlo
 
     This program is free software; you can redistribute it and/or modify
@@ -17,6 +19,7 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
+
 #include <stdarg.h>
 
 #undef TRACE