diff --git a/include/YapRegs.h b/include/YapRegs.h
new file mode 100644
index 000000000..1c79064ec
--- /dev/null
+++ b/include/YapRegs.h
@@ -0,0 +1,28 @@
+#ifndef YAP_REGS_H
+
+#define YAP_REGS_H 1
+
+#if defined(TABLING) || defined(YAPOR_SBA)
+typedef struct trail_frame {
+  Term term;
+  CELL value;
+} *tr_fr_ptr;
+
+#define TrailTerm(X)   ((X)->term)
+#else
+typedef Term *tr_fr_ptr;
+
+#define TrailTerm(X)   ((X)->term)
+#endif
+
+typedef void *choiceptr;
+
+typedef void *yamop;
+
+typedef char *ADDR;
+
+#define RESET_VARIABLE(X) (*(X) = (CELL)(X))
+
+#include "src/Regs.h"
+
+#endif
diff --git a/include/YapTags.h b/include/YapTags.h
new file mode 100644
index 000000000..587900b54
--- /dev/null
+++ b/include/YapTags.h
@@ -0,0 +1,119 @@
+/***********************************************************************/
+
+     /*
+        absrectype Term = Int + Float + Atom + Pair + Appl + Ref + Var
+
+        with AbsAppl(t) : *CELL -> Term
+        and  RepAppl(t) : Term -> *CELL
+
+        and  AbsPair(t) : *CELL -> Term
+        and  RepPair(t) : Term -> *CELL
+
+        and  IsIntTerm(t) = ...
+        and  IsAtomTerm(t) = ...
+        and  IsVarTerm(t) = ...
+        and  IsPairTerm(t) = ...
+        and  IsApplTerm(t) = ...
+        and  IsFloatTerm(t) = ...
+        and  IsRefTerm(t) = ...
+        and  IsNonVarTerm(t) = ! IsVar(t)
+        and  IsNumterm(t) = IsIntTerm(t) || IsFloatTerm(t)
+        and  IsAtomicTerm(t) = IsNumTerm(t) || IsAtomTerm(t)
+        and  IsPrimitiveTerm(t) = IsAtomicTerm(t) || IsRefTerm(t)
+
+        and  MkIntTerm(n) = ...
+        and  MkFloatTerm(f) = ...
+        and  MkAtomTerm(a) = ...
+        and  MkVarTerm(r) = ...
+        and  MkApplTerm(f,n,args) = ...
+        and  MkPairTerm(hd,tl) = ...
+        and  MkRefTerm(R) = ...
+
+        and  PtrOfTerm(t) : Term -> CELL * = ...
+        and  IntOfTerm(t) : Term -> int = ...
+        and  FloatOfTerm(t) : Term -> flt = ...
+        and  AtomOfTerm(t) : Term -> Atom = ...
+        and  VarOfTerm(t) : Term -> *Term = ....
+        and  HeadOfTerm(t) : Term -> Term = ...
+        and  TailOfTerm(t) : Term -> Term = ...
+        and  FunctorOfTerm(t) : Term -> Functor = ...
+        and  ArgOfTerm(i,t)  : Term -> Term= ...
+        and  RefOfTerm(t) : Term -> DBRef = ...
+
+      */
+
+/* 
+   YAP can use several different tag schemes, according to the kind of
+   machine we are experimenting with.
+*/
+
+#if LONG_ADDRESSES && defined(OLD_TAG_SCHEME)
+
+#include "Tags_32bits.h"
+
+#endif /* LONG_ADDRESSES && defined(OLD_TAG_SCHEME) */
+
+/* AIX will by default place mmaped segments at 0x30000000. This is
+	incompatible with the high tag scheme. Linux-ELF also does not like
+	if you place things in the lower addresses (power to the libc people).
+*/
+
+#if defined(__APPLE__)
+/* mmap on __APPLE__ is not the greatest idea. It overwrites memory allocated by malloc */
+#undef USE_DL_MALLOC
+#ifndef USE_SYSTEM_MALLOC
+#define USE_SYSTEM_MALLOC 1
+#endif
+#elif (defined(_AIX) || (defined(__APPLE__) && !defined(__LP64__)) || defined(_WIN32) || defined(sparc) || defined(__sparc) || defined(mips) || defined(__FreeBSD__) || defined(_POWER) || defined(__POWERPC__) || defined(__linux__) || defined(IN_SECOND_QUADRANT) || defined(__CYGWIN__)) || defined(__NetBSD__) || defined(__DragonFly__)
+#define USE_LOW32_TAGS 1
+#endif
+
+#if LONG_ADDRESSES && SIZEOF_INT_P==4 && !defined(OLD_TAG_SCHEME) && !defined(USE_LOW32_TAGS)
+
+#include "Tags_32Ops.h"
+
+#endif /* LONG_ADDRESSES && !defined(OLD_TAG_SCHEME) && !defined(USE_LOW32_TAGS) */
+
+#if LONG_ADDRESSES && SIZEOF_INT_P==4 && !defined(OLD_TAG_SCHEME) && defined(USE_LOW32_TAGS)
+
+#include "Tags_32LowTag.h"
+
+#endif /* LONG_ADDRESSES && !defined(OLD_TAG_SCHEME) */
+
+#if LONG_ADDRESSES && SIZEOF_INT_P==8 && !defined(OLD_TAG_SCHEME)
+
+#include "Tags_64bits.h"
+
+#endif /* LONG_ADDRESSES && SIZEOF_INT_P==8 && !defined(OLD_TAG_SCHEME) */
+
+#if !LONG_ADDRESSES
+
+#include "Tags_24bits.h"
+
+#endif /* !LONG_ADDRESSES */
+
+#ifdef TAG_LOW_BITS_32
+
+#if !GC_NO_TAGS
+#define MBIT     0x80000000
+#define RBIT     0x40000000
+
+#if IN_SECOND_QUADRANT
+#define INVERT_RBIT 1		/* RBIT is 1 by default */
+#endif
+#endif /* !GC_NO_TAGS  */
+
+#else
+
+#if !GC_NO_TAGS
+#if defined(YAPOR_SBA) && defined(__linux__)
+#define MBIT     /* 0x20000000 */ MKTAG(0x1,0)	/* mark bit */
+#else
+#define RBIT     /* 0x20000000 */ MKTAG(0x1,0)	/* relocation chain bit */
+#define MBIT     /* 0x40000000 */ MKTAG(0x2,0)	/* mark bit */
+#endif
+#endif /* !GC_NO_TAGS */
+
+#endif
+
+#define	TermSize    sizeof(Term)