diff --git a/H/Yap.h b/H/Yap.h
index 0aaf86196..313dac24f 100755
--- a/H/Yap.h
+++ b/H/Yap.h
@@ -49,6 +49,13 @@
 /* bzero */
 #include <strings.h>
 #endif
+#if HAVE_STDINT_H
+#include <stdint.h>
+#endif
+#if HAVE_INTTYPES_H
+#include <inttypes.h>
+#endif
+
 
 /*
 
@@ -445,16 +452,6 @@ extern ADDR Yap_HeapBase;
 #ifdef DEBUG
 extern int Yap_output_msg;
 #endif
-#if __ANDROID__
-#include <android/asset_manager.h>
-#include <android/asset_manager_jni.h>
-#include <android/log.h>
-#else
-inline void __android_log_print(int i, char *loc, char *msg, ...) {}
-#define ANDROID_LOG_INFO 0
-#define ANDROID_LOG_ERROR 0
-#define ANDROID_LOG_DEBUG 0
-#endif
 
 /*************************************************************************************************
                                 variables concerned with atoms table
diff --git a/H/YapHandles.h b/H/YapHandles.h
index 930bc1c5d..b4b0993a5 100755
--- a/H/YapHandles.h
+++ b/H/YapHandles.h
@@ -28,13 +28,13 @@ hence providing a way to access terms without being exposed to stack shifts or g
 of a function. Hence, slots should always be used as local variables.
 
 Slots are organized as follows:
----- Offset of next pointer in chain (tagged as an Int)
----- Number of entries (tagged as Int), in the example TAG(INT,4)
+---- Offset of next pointer in chain (tagged as an handle_t)
+---- Number of entries (tagged as handle_t), in the example TAG(INT,4)
 Entry 
 Entry 
 Entry 
 Entry 
----- Number of entries (tagged as Int), in the example TAG(INT,4)
+---- Number of entries (tagged as handle_t), in the example TAG(INT,4)
 
 Slots are not known to the yaam. Instead, A new set of slots is created when the emulator calls user C-code.
 (see YAP_Execute* functions). They are also created:
@@ -49,9 +49,9 @@ This section lists the main internal functions for slot management. These functi
 *************************************************************************************************/
 
 /// @brief start a new set of slots, linking them to the last active slots (who may, or not, be active).
-static inline Int
+static inline handle_t
 Yap_StartSlots( USES_REGS1 ) {
-  Int CurSlot = LOCAL_CurSlot;
+  handle_t CurSlot = LOCAL_CurSlot;
   // if (CurSlot == LCL0-(ASP+(IntOfTerm(ASP[0])+2)))
   //  return CurSlot;
   /* new slot */
@@ -65,56 +65,56 @@ Yap_StartSlots( USES_REGS1 ) {
 
 /// @brief reset slots to a well-known position in the stack
 static inline void
-Yap_CloseSlots( Int slot USES_REGS ) {
+Yap_CloseSlots( handle_t slot USES_REGS ) {
   LOCAL_CurSlot = slot;
 }
 
 /// @brief report the current position of the slots, assuming that they occupy the top of the stack.
-static inline Int
+static inline handle_t
 Yap_CurrentSlot( USES_REGS1 ) {
   return IntOfTerm(ASP[0]);
 }
 
 /// @brief read from a slot.
 static inline Term
-Yap_GetFromSlot(Int slot USES_REGS)
+Yap_GetFromSlot(handle_t slot USES_REGS)
 {
   return(Deref(LCL0[slot]));
 }
 
 /// @brief read from a slot. but does not try to dereference the slot.
 static inline Term
-Yap_GetDerefedFromSlot(Int slot USES_REGS)
+Yap_GetDerefedFromSlot(handle_t slot USES_REGS)
 {
   return LCL0[slot];
 }
 
 /// @brief read the object in a slot. but do not try to dereference the slot.
 static inline Term
-Yap_GetPtrFromSlot(Int slot USES_REGS)
+Yap_GetPtrFromSlot(handle_t slot USES_REGS)
 {
   return(LCL0[slot]);
 }
 
 /// @brief get the memory address of a slot
 static inline Term *
-Yap_AddressFromSlot(Int slot USES_REGS)
+Yap_AddressFromSlot(handle_t slot USES_REGS)
 {
   return(LCL0+slot);
 }
 
 /// @brief store  term in a slot
 static inline void
-Yap_PutInSlot(Int slot, Term t USES_REGS)
+Yap_PutInSlot(handle_t slot, Term t USES_REGS)
 {
   LCL0[slot] = t;
 }
 
 /// @brief allocate n empty new slots
-static inline Int
+static inline handle_t
 Yap_NewSlots(int n USES_REGS)
 {
-  Int old_slots = IntOfTerm(ASP[0]), oldn = n;
+  handle_t old_slots = IntOfTerm(ASP[0]), oldn = n;
   while (n > 0) {
     RESET_VARIABLE(ASP);
     ASP--;
@@ -128,7 +128,7 @@ Yap_NewSlots(int n USES_REGS)
 static inline Int
 Yap_InitSlot(Term t USES_REGS)
 {
-  Int old_slots = IntOfTerm(ASP[0]);
+  handle_t old_slots = IntOfTerm(ASP[0]);
   *ASP = t;
   ASP--;
   ASP[old_slots+2] = ASP[0] = MkIntTerm(old_slots+1);
@@ -137,9 +137,9 @@ Yap_InitSlot(Term t USES_REGS)
 
 /// @brief Succeeds if it is to recover the space allocated for $n$ contiguos slots starting at topSlot.
 static inline int
-Yap_RecoverSlots(int n, Int topSlot USES_REGS)
+Yap_RecoverSlots(int n, handle_t topSlot USES_REGS)
 {
-  Int old_slots = IntOfTerm(ASP[0]);
+  handle_t old_slots = IntOfTerm(ASP[0]);
   if (old_slots  < n) {
     return FALSE;
   }
diff --git a/H/YapTerm.h b/H/YapTerm.h
index 08a6b64b0..e303a4c3b 100644
--- a/H/YapTerm.h
+++ b/H/YapTerm.h
@@ -16,6 +16,13 @@
 #ifndef YAP_H
 #include "YapTermConfig.h"
 
+#if HAVE_STDINT_H
+#include <stdint.h>
+#endif
+#if HAVE_INTTYPES_H
+#include <inttypes.h>
+#endif
+
 typedef void *Functor;
 typedef void *Atom;
 
@@ -31,11 +38,12 @@ typedef void *Atom;
 /* defines integer  types Int and UInt (unsigned) with the same size as a ptr
 ** and integer types Short and UShort with half the size of a ptr */
 
+/*   */ typedef intptr_t Int;
+/*   */ typedef uintptr_t UInt;
+
 #if SIZEOF_INT_P==4
 
 #if SIZEOF_INT==4
-/*   */ typedef int Int;
-/*   */ typedef unsigned int UInt;
 
 #define Int_FORMAT "%d"
 #define UInt_FORMAT "%u"
@@ -62,23 +70,17 @@ typedef void *Atom;
 #elif SIZEOF_INT_P==8
 
 #if SIZEOF_INT==8
-/*   */ typedef int Int;
-/*   */ typedef unsigned int UInt;
 
 #define Int_FORMAT "%d"
 #define UInt_FORMAT "%u"
 
 #elif SIZEOF_LONG_INT==8
-/*   */ typedef long int Int;
-/*   */ typedef unsigned long int UInt;
 
 #define Int_FORMAT "%ld"
 #define UInt_FORMAT "%lu"
 
 #   elif SIZEOF_LONG_LONG_INT==8
-/*   */ typedef long long int Int;
-/*   */ typedef unsigned long long int UInt;
-
+/
 #define Int_FORMAT "%I64d"
 #define UInt_FORMAT "%I64u"
 
@@ -129,6 +131,8 @@ typedef UInt BITS32;
 
 typedef CELL Term;
 
+typedef Int handle_t;
+
 /*   */ typedef double Float;
 
 #if SIZEOF_INT<SIZEOF_INT_P
diff --git a/H/Yapproto.h b/H/Yapproto.h
index 112a1c4f2..1e8613fbc 100755
--- a/H/Yapproto.h
+++ b/H/Yapproto.h
@@ -369,7 +369,7 @@ int	Yap_signal_index(const char *);
 #ifdef MAC
 void	Yap_SetTextFile(char *);
 #endif
-int     Yap_getcwd(const char *, int);
+char   *Yap_getcwd(const char *, size_t);
 void    Yap_cputime_interval(Int *,Int *);
 void    Yap_systime_interval(Int *,Int *);
 void    Yap_walltime_interval(Int *,Int *);
diff --git a/H/iatoms.h b/H/iatoms.h
index ebfab56a8..3ec5c612e 100644
--- a/H/iatoms.h
+++ b/H/iatoms.h
@@ -376,7 +376,7 @@
   FunctorContext2 = Yap_MkFunctor(AtomContext,2);
   FunctorConsistencyError = Yap_MkFunctor(AtomConsistencyError,1);
   FunctorCreep = Yap_MkFunctor(AtomCreep,1);
-  FunctorCsult = Yap_MkFunctor(AtomCsult,1);
+  FunctorCsult = Yap_MkFunctor(AtomCsult,2);
   FunctorCurrentModule = Yap_MkFunctor(AtomCurrentModule,1);
   FunctorCutBy = Yap_MkFunctor(AtomCutBy,1);
   FunctorDBREF = Yap_MkFunctor(AtomDBREF,1);
diff --git a/H/pl-shared.h b/H/pl-shared.h
index 4a7f60756..e601f8b35 100755
--- a/H/pl-shared.h
+++ b/H/pl-shared.h
@@ -28,6 +28,7 @@
 #endif
 #endif
 
+
 // SWI Options
 #define O_STRING		1
 #define O_QUASIQUOTATIONS	1
@@ -383,5 +384,4 @@ CloseList(Term t0, Term tail)
 }
 
 
-
 #endif /* PL_SHARED_INCLUDE */
diff --git a/H/yapio.h b/H/yapio.h
index e2b11b553..c6c40bfa4 100644
--- a/H/yapio.h
+++ b/H/yapio.h
@@ -267,6 +267,7 @@ int   Yap_GetCharForSIGINT(void);
 Int   Yap_StreamToFileNo(Term);
 Term  Yap_OpenStream(FILE *,char *,Term,int);
 char   *Yap_TermToString(Term t, char *s, size_t sz, size_t *length, int *encoding, int flags);
+char *Yap_HandleToString(term_t l, size_t sz, size_t *length, int *encoding, int flags);
 int     Yap_GetFreeStreamD(void);
 int     Yap_GetFreeStreamDForReading(void);
 
diff --git a/Makefile.in b/Makefile.in
index b8b5a21b9..77081a491 100755
--- a/Makefile.in
+++ b/Makefile.in
@@ -514,9 +514,6 @@ c_interface.i: C/c_interface.c include/c_interface.h
 	$(CC) -E $(C_INTERF_FLAGS) C/c_interface.c > $@
 #
 
-mycb: mycb.c
-	$(CC) $(CFLAGS) mycb.c -o mycb
-
 INSTALLED_PACKAGES= \
 	library/matrix \
 	library/random \
@@ -572,7 +569,7 @@ all: startup.yss
 	-rm -f startup.yss
 	echo "bootstrap('$(srcdir)/pl/init.yap'). module(user). qsave_program('startup.yss')." |  @PRE_INSTALL_ENV@ ./yap@EXEC_SUFFIX@ -b $(srcdir)/pl/boot.yap
 
-yap@EXEC_SUFFIX@: $(HEADERS) yap.o @YAPLIB@
+yap@EXEC_SUFFIX@: $(HEADERS) yap.o @YAPLIB@ libYap.a
 	$(MPI_CC) $(EXECUTABLE_CFLAGS) $(LDFLAGS) -o yap@EXEC_SUFFIX@ yap.o @YAPLIB@ $(LIBS)
 
 yap-win: yap-win@EXEC_SUFFIX@
@@ -583,27 +580,29 @@ yap-win@EXEC_SUFFIX@: $(PLCONS_OBJECTS) $(HEADERS) @YAPLIB@
 	(cd swi/console; $(MAKE))
 	$(MPI_CC) -municode -DUNICODE -D_UNICODE $(EXECUTABLE_CFLAGS) $(LDFLAGS) -Wl,-subsystem,windows -o yap-win@EXEC_SUFFIX@ $(PLCONS_OBJECTS) plterm.dll @YAPLIB@ $(LIBS) -lgdi32 @MPILDF@
 
-libYap.a: $(LIB_OBJECTS)
+libYap.a: $(LIB_OBJECTS) yapi.o
 	-rm -f libYap.a
-	$(AR) rc libYap.a $(LIB_OBJECTS)
+	$(AR) rc libYap.a $(LIB_OBJECTS) yapi.o
 	$(RANLIB) libYap.a
 
-@DYNYAPLIB@: $(LIB_OBJECTS) yapi.o libYap.a
-	@YAPLIB_LD@ -o @YAPLIB@ $(LIB_OBJECTS) $(LIBS) $(LDFLAGS) $(SONAMEFLAG)
+@DYNYAPLIB@: $(LIB_OBJECTS)
+	@SHLIB_LD@  -o @YAPLIB@ $(LIB_OBJECTS) $(LIBS) $(LDFLAGS) $(SONAMEFLAG)
 	for p in $(EXTRAYAPLIBS); do \
 	  $(LN_S) -f @DYNYAPLIB@ $$p; \
 	done
 
-@STARTUP_ANDROID@startup.yss: 	yap@EXEC_SUFFIX@ @DYNYAPLIB@ $(PL_SOURCES) $(SWI_LIB_SOURCES) install_unix
+@STARTUP_ANDROID@startup.yss: 	yap@EXEC_SUFFIX@ @DYNYAPLIB@ $(PL_SOURCES) $(SWI_LIB_SOURCES)
 	adb shell mkdir -p /data/yap
 	adb shell mkdir -p /data/yap/pl
 	adb shell mkdir -p /data/yap/swi/library
 	adb push yap /data/yap/
 	adb push @DYNYAPLIB@ /data/yap/
+	adb push $(GMPDIR)/lib/libgmp.so data/yap/
 	adb push $(srcdir)/swi/library /data/yap/swi/library
 	adb push $(srcdir)/pl /data/yap/pl/
 	adb shell "echo \"bootstrap('/data/yap/pl/init.yap'). module(user). qsave_program('/data/yap/startup.yss').\" | LD_LIBRARY_PATH=/data/yap /data/yap/yap@EXEC_SUFFIX@ -b /data/yap/pl/boot.yap"
 	adb pull /data/yap/startup.yss
+	$(MAKE) install_unix
 
 install: @INSTALL_COMMAND@ install_startup install_common
 
@@ -733,11 +732,11 @@ install_info:
 	fi; \
 	$(INSTALL_INFO) --quiet --section "Programming Languages" --entry="`cat pillow_doc.infoindex`" --info-dir=$(DESTDIR)$(INFODIR) pillow_doc.info
 
-install_docs:
+install_docs: doxygen
 	$(MAKE) pdf
 	$(MAKE) html
-	$(INSTALL_DATA) yap.html* $(DESTDIR)$(DOCSDIR)
-	$(INSTALL_DATA) yap.pdf $(DESTDIR)$(DOCSDIR)
+	$(INSTALL_DATA) html $(DESTDIR)$(DOCSDIR)
+	$(INSTALL_DATA) pdf $(DESTDIR)$(DOCSDIR)
 	$(INSTALL_DATA) README.TXT $(DESTDIR)$(DOCSDIR)
 	$(INSTALL_DATA) Artistic $(DESTDIR)$(DOCSDIR)
 	$(INSTALL_DATA) COPYING $(DESTDIR)$(DOCSDIR)
@@ -746,6 +745,8 @@ install_docs:
 	$(INSTALL_DATA) changes-5.1.html $(DESTDIR)$(DOCSDIR)
 	$(INSTALL_DATA) changes-6.0.html $(DESTDIR)$(DOCSDIR)
 
+doxygen:
+	doxygen $(srcdir)/docs/doxygen.rc
 
 info: yap.info
 
diff --git a/YapTermConfig.h.in b/YapTermConfig.h.in
index 1b2a0b953..0e83d1de2 100644
--- a/YapTermConfig.h.in
+++ b/YapTermConfig.h.in
@@ -12,4 +12,12 @@
 #undef  SIZEOF_FLOAT
 #undef  SIZEOF_DOUBLE
 
+#ifndef HAVE_INTTYPES_H
+#undef  HAVE_INTTYPES_H
+#endif
+
+#ifndef HAVE_STDINT_H
+#undef  HAVE_STDINT_H
+#endif
+
 #endif
diff --git a/config.h.in b/config.h.in
index 4b1c2e9c2..74f1a76aa 100644
--- a/config.h.in
+++ b/config.h.in
@@ -507,6 +507,9 @@
 /* Define to 1 if you have the `pthread_mutexattr_settype' function. */
 #undef HAVE_PTHREAD_MUTEXATTR_SETTYPE
 
+/* Define to 1 if you have the `pthread_setconcurrency' function. */
+#undef HAVE_PTHREAD_SETCONCURRENCY
+
 /* Define to 1 if you have the `putenv' function. */
 #undef HAVE_PUTENV
 
diff --git a/configure b/configure
index 9c7b50124..acd623dec 100755
--- a/configure
+++ b/configure
@@ -707,6 +707,7 @@ TARGETS
 IN_SWI
 IN_YAP
 PROLOG_SYSTEM
+GCC_VERSION
 M4GENABSMI
 SAVED_STATE_PREFIX
 INSTALL_PRISM
@@ -865,7 +866,7 @@ enable_chr
 enable_clpqr
 enable_april
 enable_dlcompat
-enable_clpbn_horus
+enable_horus
 with_gmp
 with_R
 with_judy
@@ -1543,7 +1544,7 @@ Optional Features:
  --enable-clpqr            install clpqr library
  --enable-april             compile Yap to support April ILP system
  --enable-dlcompat          use dlcompat library for dynamic loading on Mac OS X
- --enable-clpbn-horus           enable CLPBN HORUS library.
+ --enable-horus           enable CLPBN HORUS library.
  --enable-myddas[=DIR]      enable the MYDDAS library
  --enable-myddas-stats      enable the MYDDAS library statistics support
  --enable-myddas-top-level  enable the MYDDAS top-level support to MySQL
@@ -4527,11 +4528,11 @@ else
 fi
 
 
-# Check whether --enable-clpbn-horus was given.
-if test "${enable_clpbn_horus+set}" = set; then :
-  enableval=$enable_clpbn_horus; yap_cv_clpbn_horus="$enableval"
+# Check whether --enable-horus was given.
+if test "${enable_horus+set}" = set; then :
+  enableval=$enable_horus; yap_cv_horus="$enableval"
 else
-  horus=yes
+  yap_cv_horus=yes
 fi
 
 
@@ -4784,7 +4785,7 @@ else
   INSTALL_PRISM="packages/prism/src/c packages/prism/src/prolog"
 fi
 
-if test "$yap_cv_clpbn_bp"="yes"; then
+if test "$yap_cv_horus"="yes"; then
   ac_ext=cpp
 ac_cpp='$CXXCPP $CPPFLAGS'
 ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
@@ -4813,7 +4814,7 @@ $as_echo "yes" >&6; }
 else
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; }
-    yap_cv_clpbn_bp=no
+    yap_cv_horus=no
 
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
@@ -4826,7 +4827,7 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
 fi
 
-if test "$yap_cv_clpbn_bp" = no
+if test "$yap_cv_horus" = no
 then
   PKG_CLPBN="packages/CLPBN"
 else
@@ -6256,7 +6257,7 @@ fi
 
   fi
 else
-  if test "$prefix" = "NONE"
+  if test "$prefix" = "NONE" -a x"$SYSROOT" = x
   then
     prefix=/usr/local
   fi
@@ -6264,8 +6265,11 @@ else
   then
      LDFLAGS="$LDFLAGS -L${prefix}/lib64"
   fi
-  LDFLAGS="$LDFLAGS -L${prefix}/lib"
-  CPPFLAGS="$CPPFLAGS -I${prefix}/include"
+  if test x"$SYSROOT" = x
+  then
+    LDFLAGS="$LDFLAGS -L${prefix}/lib"
+    CPPFLAGS="$CPPFLAGS -I${prefix}/include"
+  fi
   if test "$exec_prefix" != "NONE" -a "$exec_prefix" != "$prefix"
   then
      if test -d "${exec_prefix}/lib64" -a "$YAP_TARGET" = amd64; then
@@ -6317,7 +6321,7 @@ _ACEOF
 
 fi
 
-		   	{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for main in -llog" >&5
+		   { $as_echo "$as_me:${as_lineno-$LINENO}: checking for main in -llog" >&5
 $as_echo_n "checking for main in -llog... " >&6; }
 if ${ac_cv_lib_log_main+:} false; then :
   $as_echo_n "(cached) " >&6
@@ -6990,7 +6994,7 @@ fi
 
 done
 
-  for ac_func in pthread_mutexattr_setkind_np pthread_mutexattr_settype
+  for ac_func in pthread_mutexattr_setkind_np pthread_mutexattr_settype pthread_setconcurrency
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
@@ -8041,7 +8045,7 @@ fi
 
 done
 
-for ac_header in float.h fpu_control.h ieeefp.h io.h limits.h
+for ac_header in float.h fpu_control.h ieeefp.h inttypes.h io.h limits.h
 do :
   as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
 ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"
@@ -9567,6 +9571,8 @@ case "$host" in
     *android*)
       echo "no locale"
       SAVED_STATE_PREFIX="/assets/lib/Yap/"
+
+
       ;;
       **)
       for ac_header in locale.h
@@ -10699,7 +10705,11 @@ case "$CPP" in
 	*) ACPP="$CPP"
 esac
 
-( CC=$ACC; LD=$ALD; CPP=$ACPP; CFLAGS=$SHLIB_CFLAGS; LDFLAGS=$LDFLAGS;
+( if test x"$SYSROOT" != x; then
+   CC="$ACC  --sysroot=$SYSROOT"; LD=$ALD; CPP="$ACPP  --sysroot=$SYSROOT"; CFLAGS=$SHLIB_CFLAGS; LDFLAGS=$LDFLAGS;
+  else
+   CC=$ACC; LD=$ALD; CPP=$ACPP; CFLAGS=$SHLIB_CFLAGS; LDFLAGS=$LDFLAGS;
+  fi
   export CC LD CFLAGS LDFLAGS;
   mkdir -p packages/clib/maildrop/rfc822;
   mkdir -p packages/clib/maildrop/rfc2045;
@@ -12629,7 +12639,7 @@ else
 JAVA_TEST=Test.java
 CLASS_TEST=Test.class
 cat << \EOF > $JAVA_TEST
-/* #line 12632 "configure" */
+/* #line 12642 "configure" */
 public class Test {
 }
 EOF
@@ -12805,7 +12815,7 @@ EOF
 if uudecode$EXEEXT Test.uue; then
         ac_cv_prog_uudecode_base64=yes
 else
-        echo "configure: 12808: uudecode had trouble decoding base 64 file 'Test.uue'" >&5
+        echo "configure: 12818: uudecode had trouble decoding base 64 file 'Test.uue'" >&5
         echo "configure: failed file was:" >&5
         cat Test.uue >&5
         ac_cv_prog_uudecode_base64=no
@@ -12936,7 +12946,7 @@ else
 JAVA_TEST=Test.java
 CLASS_TEST=Test.class
 cat << \EOF > $JAVA_TEST
-/* #line 12939 "configure" */
+/* #line 12949 "configure" */
 public class Test {
 }
 EOF
@@ -12971,7 +12981,7 @@ JAVA_TEST=Test.java
 CLASS_TEST=Test.class
 TEST=Test
 cat << \EOF > $JAVA_TEST
-/* [#]line 12974 "configure" */
+/* [#]line 12984 "configure" */
 public class Test {
 public static void main (String args[]) {
         System.exit (0);
@@ -15741,7 +15751,7 @@ else
 fi
 
 
-if test -d /usr/local/include/gecode; then
+if test -d /usr/local/include/gecode -a x$SYSROOT = x; then
   CFLAGS="$CFLAGS -I/usr/local/include"
   SHLIB_CXXFLAGS="$SHLIB_CXXFLAGS -I/usr/local/include"
   GECODE_EXTRALIBS="-L/usr/local/lib"
@@ -15961,7 +15971,7 @@ _ACEOF
 
 
 cat >>confdefs.h <<_ACEOF
-#define C_CFLAGS "$CFLAGS $YAP_EXTRAS $DEFS  -D_YAP_NOT_INSTALLED_=1 $CPPFLAGS  -I. -I$srcdir/H -I$srcdir/include  -I$srcdir/os -I$srcdir/OPTYap -I$srcdir/BEAM"
+#define C_CFLAGS "$CFLAGS $YAP_EXTRAS $  -D_YAP_NOT_INSTALLED_=1 $CPPFLAGS  -I. -I$srcdir/H -I$srcdir/include  -I$srcdir/os -I$srcdir/OPTYap -I$srcdir/BEAM"
 _ACEOF
 
 
diff --git a/configure.in b/configure.in
index b80cb13ea..06f27afd3 100755
--- a/configure.in
+++ b/configure.in
@@ -184,9 +184,9 @@ AC_ARG_ENABLE(dlcompat,
 	[ --enable-dlcompat          use dlcompat library for dynamic loading on Mac OS X],
 	use_dlcompat="$enableval", use_dlcompat=no)
 
-AC_ARG_ENABLE(clpbn-horus,
-	[ --enable-clpbn-horus           enable CLPBN HORUS library.  ],
-	yap_cv_clpbn_horus="$enableval", horus=yes)
+AC_ARG_ENABLE(horus,
+	[ --enable-horus           enable CLPBN HORUS library.  ],
+	yap_cv_horus="$enableval", yap_cv_horus=yes)
 
 AC_ARG_WITH(gmp,
 	[ --with-gmp[=DIR]           use GNU Multiple Precision in DIR],
@@ -368,7 +368,7 @@ else
   INSTALL_PRISM="packages/prism/src/c packages/prism/src/prolog"
 fi
 
-if test "$yap_cv_clpbn_bp"="yes"; then
+if test "$yap_cv_horus"="yes"; then
   AC_LANG_PUSH([C++])
   my_save_cxxflags="$CXXFLAGS"
   CXXFLAGS=-std=c++0x
@@ -376,13 +376,13 @@ if test "$yap_cv_clpbn_bp"="yes"; then
   AC_COMPILE_IFELSE([AC_LANG_PROGRAM([])],
     [AC_MSG_RESULT([yes])],
     [AC_MSG_RESULT([no])]
-    [yap_cv_clpbn_bp=no]
+    [yap_cv_horus=no]
   )
   CXXFLAGS="$my_save_cxxflags"
   AC_LANG_POP()
 fi
 
-if test "$yap_cv_clpbn_bp" = no
+if test "$yap_cv_horus" = no
 then
   PKG_CLPBN="packages/CLPBN"
 else
@@ -597,7 +597,7 @@ then
     AC_CHECK_LIB(pthread,pthread_create)
   fi
 else
-  if test "$prefix" = "NONE"
+  if test "$prefix" = "NONE" -a x"$SYSROOT" = x
   then
     prefix=/usr/local
   fi
@@ -605,8 +605,11 @@ else
   then
      LDFLAGS="$LDFLAGS -L${prefix}/lib64"
   fi
-  LDFLAGS="$LDFLAGS -L${prefix}/lib"
-  CPPFLAGS="$CPPFLAGS -I${prefix}/include"
+  if test x"$SYSROOT" = x
+  then
+    LDFLAGS="$LDFLAGS -L${prefix}/lib"
+    CPPFLAGS="$CPPFLAGS -I${prefix}/include"
+  fi
   if test "$exec_prefix" != "NONE" -a "$exec_prefix" != "$prefix"
   then
      if test -d "${exec_prefix}/lib64" -a "$YAP_TARGET" = amd64; then
@@ -620,7 +623,7 @@ else
   case "$host" in
 		*android*)
 		   AC_CHECK_LIB(android,main)
-		   	AC_CHECK_LIB(log,main)
+		   AC_CHECK_LIB(log,main)
 			;;
 			**)
        STARTUP_ANDROID="x"
@@ -672,7 +675,7 @@ fi
 if test "$threads" = yes
 then
   AC_CHECK_HEADERS(pthread.h)
-  AC_CHECK_FUNCS(pthread_mutexattr_setkind_np pthread_mutexattr_settype)
+  AC_CHECK_FUNCS(pthread_mutexattr_setkind_np pthread_mutexattr_settype pthread_setconcurrency)
   if test "$pthreadlocking" = yes
   then
     AC_DEFINE(USE_PTHREAD_LOCKING, 1, [do not use our own locking routines])
@@ -1238,7 +1241,7 @@ AC_HEADER_SYS_WAIT
 AC_CHECK_HEADERS(arpa/inet.h alloca.h crtdbg.h crypt.h)
 AC_CHECK_HEADERS(ctype.h direct.h dirent.h dlfcn.h)
 AC_CHECK_HEADERS(errno.h execinfo.h fcntl.h fenv.h)
-AC_CHECK_HEADERS(float.h fpu_control.h ieeefp.h io.h limits.h)
+AC_CHECK_HEADERS(float.h fpu_control.h ieeefp.h inttypes.h io.h limits.h)
 AC_CHECK_HEADERS(malloc.h math.h memory.h)
 AC_CHECK_HEADERS(netdb.h netinet/in.h netinet/tcp.h pwd.h regex.h shlobj.h)
 AC_CHECK_HEADERS(siginfo.h signal.h stdarg.h stdint.h string.h stropts.h)
@@ -1655,6 +1658,8 @@ case "$host" in
     *android*)
       echo "no locale"
       SAVED_STATE_PREFIX="/assets/lib/Yap/"
+      AC_SUBST(C_PARSER_FLAGS)
+      AC_SUBST(GCC_VERSION)
       ;;
       **)
       AC_CHECK_HEADERS(locale.h)
@@ -2027,7 +2032,7 @@ yap_nversion=`expr $YAP_MAJOR_VERSION \* 10000 + $YAP_MINOR_VERSION \* 100 + $YA
 yap_startup=startup.yss
 
 AC_DEFINE_UNQUOTED( C_CC, [ "$CC" ], [c-compiler used])
-AC_DEFINE_UNQUOTED( C_CFLAGS, ["$CFLAGS $YAP_EXTRAS $DEFS  -D_YAP_NOT_INSTALLED_=1 $CPPFLAGS  -I. -I$srcdir/H -I$srcdir/include  -I$srcdir/os -I$srcdir/OPTYap -I$srcdir/BEAM" ], [compilation flags])
+AC_DEFINE_UNQUOTED( C_CFLAGS, ["$CFLAGS $YAP_EXTRAS $  -D_YAP_NOT_INSTALLED_=1 $CPPFLAGS  -I. -I$srcdir/H -I$srcdir/include  -I$srcdir/os -I$srcdir/OPTYap -I$srcdir/BEAM" ], [compilation flags])
 AC_DEFINE_UNQUOTED( C_LDFLAGS, [ "$LDFLAGS" ], [linking flags])
 AC_DEFINE_UNQUOTED( C_LIBS, [ "$LIBS" ], [main libs for YAP])
 AC_DEFINE_UNQUOTED( C_LIBPLSO, [ "$LIBS $EXTRA_LIBS_FOR_DLLS" ], [libs for linking with DLLs])
diff --git a/include/SWI-Prolog.h b/include/SWI-Prolog.h
index e70f2095f..8336747f9 100755
--- a/include/SWI-Prolog.h
+++ b/include/SWI-Prolog.h
@@ -136,7 +136,7 @@ typedef unsigned long uintptr_t;
 
 #ifndef PL_HAVE_TERM_T
 #define PL_HAVE_TERM_T
-typedef	uintptr_t    term_t;
+typedef	intptr_t    term_t;
 #endif
 typedef	struct mod_entry *module_t;
 typedef struct DB_STRUCT *record_t;
@@ -505,7 +505,7 @@ extern X_API  int PL_compare(term_t, term_t);
 /* begin PL_unify_* functions =============================*/
 extern X_API  int PL_unify(term_t, term_t);
 extern X_API  int PL_unify_atom(term_t, atom_t);
-extern X_API  int PL_unify_arg(int, term_t, atom_t);
+extern X_API  int PL_unify_arg(int, term_t, term_t);
 extern X_API  int PL_unify_atom_chars(term_t, const char *);
 extern X_API  int PL_unify_atom_nchars(term_t, size_t len, const char *);
 extern X_API  int PL_unify_float(term_t, double);
diff --git a/include/YapDefs.h b/include/YapDefs.h
index 052ca55c3..4b154a345 100755
--- a/include/YapDefs.h
+++ b/include/YapDefs.h
@@ -43,6 +43,8 @@ typedef Term YAP_Module;
 
 typedef int YAP_Bool;
 
+typedef handle_t YAP_handle_t;
+
 #define YAP_PredEntryPtr struct pred_entry *
 
 #define YAP_UserCPred CPredicate
@@ -91,6 +93,8 @@ typedef double YAP_Float;
 #define FALSE	0
 #endif
 
+typedef YAP_Int YAP_handle_t;
+
 typedef struct YAP_pred_entry *YAP_PredEntryPtr;
 
 typedef YAP_Bool (* YAP_UserCPred)(void);
@@ -110,6 +114,9 @@ typedef struct YAP_thread_attr_struct {
   YAP_Term              egoal, alias;
 } YAP_thread_attr;
 
+#ifdef YAP_H
+#include <threads.h>
+#endif
 
 typedef enum {
   YAP_TAG_ATT = 0x1,
@@ -293,4 +300,16 @@ typedef enum
     YAPC_ENABLE_AGC                 /* enable or disable atom garbage collection */
   } yap_flag_t;
 
+
+#if __ANDROID__
+#include <android/asset_manager.h>
+#include <android/asset_manager_jni.h>
+#include <android/log.h>
+#else
+    inline void __android_log_print(int i, const char loc[], const char msg[], ...) {}
+#define ANDROID_LOG_INFO 0
+#define ANDROID_LOG_ERROR 0
+#define ANDROID_LOG_DEBUG 0
+#endif
+
 #endif /* _YAPDEFS_H */
diff --git a/include/YapInterface.h b/include/YapInterface.h
index bc32b7cbc..1ae36c42b 100755
--- a/include/YapInterface.h
+++ b/include/YapInterface.h
@@ -420,31 +420,31 @@ extern X_API void YAP_FlushAllStreams(void);
 #define YAP_SEEKABLE_STREAM	0x80
 
 /*  YAP_Term  *YAP_NewSlots()  */
-extern X_API YAP_Int YAP_NewSlots(int);
+extern X_API YAP_handle_t YAP_NewSlots(int);
 
 /*  YAP_Int  YAP_CurrentSlot()  */
-extern X_API YAP_Int YAP_CurrentSlot(void);
+extern X_API YAP_handle_t YAP_CurrentSlot(void);
 
 /*  YAP_Term  *YAP_InitSlot()  */
-extern X_API YAP_Int YAP_InitSlot(YAP_Term);
+extern X_API YAP_handle_t YAP_InitSlot(YAP_Term);
 
 /*  YAP_Term  YAP_GetFromSlots(t)  */
-extern X_API YAP_Term YAP_GetFromSlot(YAP_Int);
+extern X_API YAP_Term YAP_GetFromSlot(YAP_handle_t);
 
 /*  YAP_Term  *YAP_AddressFromSlots(t)  */
-extern X_API YAP_Term *YAP_AddressFromSlot(YAP_Int);
+extern X_API YAP_Term *YAP_AddressFromSlot(YAP_handle_t);
 
 /*  YAP_Term  *YAP_AddressOfTermInSlot(t)  */
-extern X_API YAP_Term *YAP_AddressOfTermInSlot(YAP_Int);
+extern X_API YAP_Term *YAP_AddressOfTermInSlot(YAP_handle_t);
 
 /*  YAP_Term  YAP_PutInSlots(t)  */
-extern X_API void YAP_PutInSlot(YAP_Int, YAP_Term);
+extern X_API void YAP_PutInSlot(YAP_handle_t, YAP_Term);
 
-extern X_API int YAP_RecoverSlots(int n, YAP_Int top_slot);
+extern X_API int YAP_RecoverSlots(int n, YAP_handle_t top_slot);
 
-extern X_API YAP_Int YAP_ArgsToSlots(int);
+extern X_API YAP_handle_t YAP_ArgsToSlots(int);
 
-extern X_API void YAP_SlotsToArgs(int, YAP_Int);
+extern X_API void YAP_SlotsToArgs(int, YAP_handle_t);
 
 /*  void  YAP_Throw()  */
 extern X_API void YAP_Throw(YAP_Term);
diff --git a/library/system/sys.c b/library/system/sys.c
index 35eadc50d..94450dbc0 100644
--- a/library/system/sys.c
+++ b/library/system/sys.c
@@ -295,6 +295,23 @@ list_directory(void)
     YAP_PutInSlot(sl,YAP_MkPairTerm(ti, YAP_GetFromSlot(sl)));
   }
   _findclose( hFile );
+#elif __ANDROID__
+ {
+    extern AAssetManager *assetManager;
+     const char *dirName = buf+strlen("/assets/");
+     AAssetManager* mgr = assetManager;
+    AAssetDir	 *de;
+    const char* dp;
+
+   if ((de = AAssetManager_openDir(mgr, dirName)) == NULL) {
+     return(YAP_Unify(YAP_ARG3, YAP_MkIntTerm(errno)));
+   }
+   while (( dp = AAssetDir_getNextFileName(de))) {
+     YAP_Term ti = YAP_MkAtomTerm(YAP_LookupAtom(dp));
+     YAP_PutInSlot(sl,YAP_MkPairTerm(ti, YAP_GetFromSlot(sl)));
+   }
+   AAssetDir_close(de);
+ }
 #elif HAVE_OPENDIR
  {
    DIR *de;
diff --git a/misc/ATOMS b/misc/ATOMS
index 6c70026b2..bfb8c5654 100644
--- a/misc/ATOMS
+++ b/misc/ATOMS
@@ -381,7 +381,7 @@ F	CommentHook		CommentHook	3
 F	Context2		Context		2
 F	ConsistencyError	ConsistencyError	1
 F	Creep			Creep		1
-F	Csult			Csult		1
+F	Csult			Csult		2
 F	CurrentModule		CurrentModule	1
 F	CutBy			CutBy		1
 F	DBREF			DBREF		1
diff --git a/misc/LOCALS b/misc/LOCALS
index 001839bc8..1849ae64b 100755
--- a/misc/LOCALS
+++ b/misc/LOCALS
@@ -269,7 +269,7 @@ UInt				exo_arg					=0
 struct scan_atoms*		search_atoms				void
 
 // Slots
-Int				CurSlot					=0
+handle_t				CurSlot					=0
 
 
 Term				SourceModule				=0
diff --git a/packages/gecode/configure.in b/packages/gecode/configure.in
index a3fa90a1a..6fbcfc6c1 100755
--- a/packages/gecode/configure.in
+++ b/packages/gecode/configure.in
@@ -5,7 +5,7 @@ AC_ARG_ENABLE(gecode,
         [use_gecode="$enableval"], use_gecode=no)
 
 dnl gecode is usually in /usr/local
-if test -d /usr/local/include/gecode; then
+if test -d /usr/local/include/gecode -a x$SYSROOT = x; then
   CFLAGS="$CFLAGS -I/usr/local/include"
   SHLIB_CXXFLAGS="$SHLIB_CXXFLAGS -I/usr/local/include"
   GECODE_EXTRALIBS="-L/usr/local/lib"