Limiting runtime limit checks in 'pdr'.

10 files changed, 1266 insertions, 2 deletions

diff --git a/Makefile b/Makefile
index 0950b167..ad1f6691 100644
--- a/Makefile
+++ b/Makefile
@@ -23,7 +23,8 @@ MODULES := \
 	src/opt/ret src/opt/res src/opt/lpk src/opt/nwk src/opt/rwt \
 	src/opt/cgt src/opt/csw src/opt/dar src/opt/dau src/opt/sfm \
 	src/sat/bsat src/sat/csat src/sat/msat src/sat/psat src/sat/cnf src/sat/bmc \
-	src/bool/bdc src/bool/deco src/bool/dec src/bool/kit src/bool/lucky src/bool/rsb \
+	src/bool/bdc src/bool/deco src/bool/dec src/bool/kit src/bool/lucky \
+	src/bool/rsb src/bool/rpo \
 	src/proof/pdr src/proof/int src/proof/bbr src/proof/llb src/proof/live \
 	src/proof/cec src/proof/dch src/proof/fraig src/proof/fra src/proof/ssw \
 	src/proof/abs src/proof/ssc \
diff --git a/abclib.dsp b/abclib.dsp
index 6175d0fa..d19dfee7 100644
--- a/abclib.dsp
+++ b/abclib.dsp
@@ -3886,6 +3886,10 @@ SOURCE=.\src\bool\rsb\rsbInt.h
 SOURCE=.\src\bool\rsb\rsbMan.c
 # End Source File
 # End Group
+# Begin Group "rpo"
+
+# PROP Default_Filter ""
+# End Group
 # End Group
 # Begin Group "prove"
 
diff --git a/src/base/abci/abc.c b/src/base/abci/abc.c
index ef973099..063388f7 100644
--- a/src/base/abci/abc.c
+++ b/src/base/abci/abc.c
@@ -53,6 +53,7 @@
 #include "sat/bmc/bmc.h"
 #include "proof/ssc/ssc.h"
 #include "opt/sfm/sfm.h"
+#include "bool/rpo/rpo.h"
 
 #ifndef _WIN32
 #include <unistd.h>
@@ -113,6 +114,7 @@ static int Abc_CommandAddBuffs               ( Abc_Frame_t * pAbc, int argc, cha
 //static int Abc_CommandMerge                  ( Abc_Frame_t * pAbc, int argc, char ** argv );
 static int Abc_CommandTestDec                ( Abc_Frame_t * pAbc, int argc, char ** argv );
 static int Abc_CommandTestNpn                ( Abc_Frame_t * pAbc, int argc, char ** argv );
+static int Abc_CommandTestRPO                ( Abc_Frame_t * pAbc, int argc, char ** argv );
 
 static int Abc_CommandRewrite                ( Abc_Frame_t * pAbc, int argc, char ** argv );
 static int Abc_CommandRefactor               ( Abc_Frame_t * pAbc, int argc, char ** argv );
@@ -663,6 +665,7 @@ void Abc_Init( Abc_Frame_t * pAbc )
 //    Cmd_CommandAdd( pAbc, "Synthesis",    "merge",         Abc_CommandMerge,            1 );
     Cmd_CommandAdd( pAbc, "Synthesis",    "testdec",       Abc_CommandTestDec,          0 );
     Cmd_CommandAdd( pAbc, "Synthesis",    "testnpn",       Abc_CommandTestNpn,          0 );
+    Cmd_CommandAdd( pAbc, "LogiCS",       "testrpo",       Abc_CommandTestRPO,          0 );
 
     Cmd_CommandAdd( pAbc, "Synthesis",    "rewrite",       Abc_CommandRewrite,          1 );
     Cmd_CommandAdd( pAbc, "Synthesis",    "refactor",      Abc_CommandRefactor,         1 );
@@ -5323,6 +5326,81 @@ usage:
     return 1;
 }
 
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Abc_CommandTestRPO(Abc_Frame_t * pAbc, int argc, char ** argv) {
+    extern int Abc_RpoTest(char * pFileName, int nVarNum, int nThreshold, int fVerbose);
+    char * pFileName;
+    int c;
+    int nVarNum = -1;
+    int fVerbose = 0;
+    int nThreshold = -1;
+    Extra_UtilGetoptReset();
+    while ((c = Extra_UtilGetopt(argc, argv, "TNvh")) != EOF) {
+        switch (c) {
+            case 'N':
+                if (globalUtilOptind >= argc) {
+                    Abc_Print(-1, "Command line switch \"-N\" should be followed by an integer.\n");
+                    goto usage;
+                }
+                nVarNum = atoi(argv[globalUtilOptind]);
+                globalUtilOptind++;
+                if (nVarNum < 0)
+                    goto usage;
+                break;
+            case 'T':
+                if (globalUtilOptind >= argc) {
+                    Abc_Print(-1, "Command line switch \"-T\" should be followed by an integer.\n");
+                    goto usage;
+                }
+                nThreshold = atoi(argv[globalUtilOptind]);
+                globalUtilOptind++;
+                if (nThreshold < 0)
+                    goto usage;
+                break;
+            case 'v':
+                fVerbose ^= 1;
+                break;
+            case 'h':
+                goto usage;
+            default:
+                goto usage;
+        }
+    }
+    if (argc != globalUtilOptind + 1) 
+    {
+        Abc_Print(1, "Input file is not given.\n");
+        goto usage;
+    }
+    // get the output file name
+    pFileName = argv[globalUtilOptind];
+    // call the testbench
+    Abc_RpoTest( pFileName, nVarNum, nThreshold, fVerbose );
+    return 0;
+
+usage:
+    Abc_Print(-2, "usage: testrpo [-NT <num>] [-vh] <file>\n");
+    Abc_Print(-2, "\t           RPO algorithm developed and implemented by Mayler G. A. Martins,\n");
+    Abc_Print(-2, "\t           Vinicius Callegaro, Renato P. Ribas and Andre' I. Reis\n");
+    Abc_Print(-2, "\t           at Federal University of Rio Grande do Sul, Porto Alegre, Brazil\n");
+    Abc_Print(-2, "\t-N <num> : the number of support variables (binary files only) [default = unused]\n");
+    Abc_Print(-2, "\t-T <num> : the number of recursions accepted before abort [default = INFINITE]\n");
+    Abc_Print(-2, "\t-v       : toggle verbose printout [default = %s]\n", fVerbose ? "yes" : "no");
+    Abc_Print(-2, "\t-h       : print the command usage\n");
+    Abc_Print(-2, "\t<file>   : a text file with truth tables in hexadecimal, listed one per line,\n");
+    Abc_Print(-2, "\t           or a binary file with an array of truth tables (in this case,\n");
+    Abc_Print(-2, "\t           -N <num> is required to determine how many functions are stored)\n");
+    return 1;
+}
 
 /**Function*************************************************************
 
diff --git a/src/base/abci/abcRpo.c b/src/base/abci/abcRpo.c
new file mode 100644
index 00000000..286ef80b
--- /dev/null
+++ b/src/base/abci/abcRpo.c
@@ -0,0 +1,442 @@
+/**CFile****************************************************************
+
+  FileName    [abcRpo.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [Rpo package.]
+
+  Synopsis    [Procedures for executing RPO.]
+
+  Author      [Mayler G. A. Martins / Vinicius Callegaro]
+  
+  Affiliation [UFRGS]
+
+  Date        [Ver. 1.0. Started - May 08, 2013.]
+
+  Revision    [$Id: abcRpo.c,v 1.00 2013/05/08 00:00:00 mgamartins Exp $]
+
+ ***********************************************************************/
+
+#include "misc/extra/extra.h"
+
+#include "bool/rpo/rpo.h"
+#include "bool/rpo/literal.h"
+
+ABC_NAMESPACE_IMPL_START
+
+
+// data-structure to store a bunch of truth tables
+typedef struct Rpo_TtStore_t_ Rpo_TtStore_t;
+
+struct Rpo_TtStore_t_ {
+    int nVars;
+    int nWords;
+    int nFuncs;
+    word ** pFuncs;
+};
+
+
+// read/write/flip i-th bit of a bit string table:
+
+static inline int Abc_TruthGetBit(word * p, int i) {
+    return (int) (p[i >> 6] >> (i & 63)) & 1;
+}
+
+static inline void Abc_TruthSetBit(word * p, int i) {
+    p[i >> 6] |= (((word) 1) << (i & 63));
+}
+
+static inline void Abc_TruthXorBit(word * p, int i) {
+    p[i >> 6] ^= (((word) 1) << (i & 63));
+}
+
+// read/write k-th digit d of a hexadecimal number:
+
+static inline int Abc_TruthGetHex(word * p, int k) {
+    return (int) (p[k >> 4] >> ((k << 2) & 63)) & 15;
+}
+
+static inline void Abc_TruthSetHex(word * p, int k, int d) {
+    p[k >> 4] |= (((word) d) << ((k << 2) & 63));
+}
+
+static inline void Abc_TruthXorHex(word * p, int k, int d) {
+    p[k >> 4] ^= (((word) d) << ((k << 2) & 63));
+}
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+// read one hex character
+
+static inline int Abc_TruthReadHexDigit(char HexChar) {
+    if (HexChar >= '0' && HexChar <= '9')
+        return HexChar - '0';
+    if (HexChar >= 'A' && HexChar <= 'F')
+        return HexChar - 'A' + 10;
+    if (HexChar >= 'a' && HexChar <= 'f')
+        return HexChar - 'a' + 10;
+    assert(0); // not a hexadecimal symbol
+    return -1; // return value which makes no sense
+}
+
+// write one hex character
+
+static inline void Abc_TruthWriteHexDigit(FILE * pFile, int HexDigit) {
+    assert(HexDigit >= 0 && HexDigit < 16);
+    if (HexDigit < 10)
+        fprintf(pFile, "%d", HexDigit);
+    else
+        fprintf(pFile, "%c", 'A' + HexDigit - 10);
+}
+
+// read one truth table in hexadecimal
+
+static void Abc_TruthReadHex(word * pTruth, char * pString, int nVars) {
+    int nWords = (nVars < 7) ? 1 : (1 << (nVars - 6));
+    int k, Digit, nDigits = (nWords << 4);
+    char EndSymbol;
+    // skip the first 2 symbols if they are "0x"
+    if (pString[0] == '0' && pString[1] == 'x')
+        pString += 2;
+    // get the last symbol
+    EndSymbol = pString[nDigits];
+    // the end symbol of the TT (the one immediately following hex digits)
+    // should be one of the following: space, a new-line, or a zero-terminator
+    // (note that on Windows symbols '\r' can be inserted before each '\n')
+    assert(EndSymbol == ' ' || EndSymbol == '\n' || EndSymbol == '\r' || EndSymbol == '\0');
+    // read hexadecimal digits in the reverse order
+    // (the last symbol in the string is the least significant digit)
+    for (k = 0; k < nDigits; k++) {
+        Digit = Abc_TruthReadHexDigit(pString[nDigits - 1 - k]);
+        assert(Digit >= 0 && Digit < 16);
+        Abc_TruthSetHex(pTruth, k, Digit);
+    }
+}
+
+// write one truth table in hexadecimal (do not add end-of-line!)
+
+static void Abc_TruthWriteHex(FILE * pFile, word * pTruth, int nVars) {
+    int nDigits, Digit, k;
+    nDigits = (1 << (nVars - 2));
+    for (k = 0; k < nDigits; k++) {
+        Digit = Abc_TruthGetHex(pTruth, k);
+        assert(Digit >= 0 && Digit < 16);
+        Abc_TruthWriteHexDigit(pFile, Digit);
+    }
+}
+
+
+
+/**Function*************************************************************
+
+  Synopsis    [Allocate/Deallocate storage for truth tables..]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+ ***********************************************************************/
+static Rpo_TtStore_t * Abc_TruthStoreAlloc(int nVars, int nFuncs) {
+    Rpo_TtStore_t * p;
+    int i;
+    p = (Rpo_TtStore_t *) malloc(sizeof (Rpo_TtStore_t));
+    p->nVars = nVars;
+    p->nWords = (nVars < 7) ? 1 : (1 << (nVars - 6));
+    p->nFuncs = nFuncs;
+    // alloc storage for 'nFuncs' truth tables as one chunk of memory
+    p->pFuncs = (word **) malloc((sizeof (word *) + sizeof (word) * p->nWords) * p->nFuncs);
+    // assign and clean the truth table storage
+    p->pFuncs[0] = (word *) (p->pFuncs + p->nFuncs);
+    memset(p->pFuncs[0], 0, sizeof (word) * p->nWords * p->nFuncs);
+    // split it up into individual truth tables
+    for (i = 1; i < p->nFuncs; i++)
+        p->pFuncs[i] = p->pFuncs[i - 1] + p->nWords;
+    return p;
+}
+
+static Rpo_TtStore_t * Abc_TruthStoreAlloc2(int nVars, int nFuncs, word * pBuffer) {
+    Rpo_TtStore_t * p;
+    int i;
+    p = (Rpo_TtStore_t *) malloc(sizeof (Rpo_TtStore_t));
+    p->nVars = nVars;
+    p->nWords = (nVars < 7) ? 1 : (1 << (nVars - 6));
+    p->nFuncs = nFuncs;
+    // alloc storage for 'nFuncs' truth tables as one chunk of memory
+    p->pFuncs = (word **) malloc(sizeof (word *) * p->nFuncs);
+    // assign and clean the truth table storage
+    p->pFuncs[0] = pBuffer;
+    // split it up into individual truth tables
+    for (i = 1; i < p->nFuncs; i++)
+        p->pFuncs[i] = p->pFuncs[i - 1] + p->nWords;
+    return p;
+}
+
+static void Abc_TtStoreFree(Rpo_TtStore_t * p, int nVarNum) {
+    if (nVarNum >= 0)
+        ABC_FREE(p->pFuncs[0]);
+    ABC_FREE(p->pFuncs);
+    ABC_FREE(p);
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Read file contents.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+ ***********************************************************************/
+extern int Abc_FileSize(char * pFileName);
+
+/**Function*************************************************************
+
+  Synopsis    [Read file contents.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+ ***********************************************************************/
+extern char * Abc_FileRead(char * pFileName);
+
+/**Function*************************************************************
+
+  Synopsis    [Determine the number of variables by reading the first line.]
+
+  Description [Determine the number of functions by counting the lines.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+ ***********************************************************************/
+extern void Abc_TruthGetParams(char * pFileName, int * pnVars, int * pnTruths);
+
+
+/**Function*************************************************************
+
+  Synopsis    [Read truth tables from file.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+ ***********************************************************************/
+static void Abc_TruthStoreRead(char * pFileName, Rpo_TtStore_t * p) {
+    char * pContents;
+    int i, nLines;
+    pContents = Abc_FileRead(pFileName);
+    if (pContents == NULL)
+        return;
+    // here it is assumed (without checking!) that each line of the file 
+    // begins with a string of hexadecimal chars followed by space
+
+    // the file will be read till the first empty line (pContents[i] == '\n')
+    // (note that Abc_FileRead() added several empty lines at the end of the file contents)
+    for (nLines = i = 0; pContents[i] != '\n';) {
+        // read one line
+        Abc_TruthReadHex(p->pFuncs[nLines++], &pContents[i], p->nVars);
+        // skip till after the end-of-line symbol
+        // (note that end-of-line symbol is also skipped)
+        while (pContents[i++] != '\n');
+    }
+    // adjust the number of functions read 
+    // (we may have allocated more storage because some lines in the file were empty)
+    assert(p->nFuncs >= nLines);
+    p->nFuncs = nLines;
+    ABC_FREE(pContents);
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Write truth tables into file.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+ ***********************************************************************/
+static void Abc_TtStoreWrite(char * pFileName, Rpo_TtStore_t * p, int fBinary) {
+    FILE * pFile;
+    int i, nBytes = 8 * Abc_Truth6WordNum(p->nVars);
+    pFile = fopen(pFileName, "wb");
+    if (pFile == NULL) {
+        printf("Cannot open file \"%s\" for writing.\n", pFileName);
+        return;
+    }
+    for (i = 0; i < p->nFuncs; i++) {
+        if (fBinary)
+            fwrite(p->pFuncs[i], nBytes, 1, pFile);
+        else
+            Abc_TruthWriteHex(pFile, p->pFuncs[i], p->nVars), fprintf(pFile, "\n");
+    }
+    fclose(pFile);
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Read truth tables from input file and write them into output file.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+ ***********************************************************************/
+static Rpo_TtStore_t * Abc_TtStoreLoad(char * pFileName, int nVarNum) {
+    Rpo_TtStore_t * p;
+    if (nVarNum < 0) {
+        int nVars, nTruths;
+        // figure out how many truth table and how many variables
+        Abc_TruthGetParams(pFileName, &nVars, &nTruths);
+        if (nVars < 2 || nVars > 16 || nTruths == 0)
+            return NULL;
+        // allocate data-structure
+        p = Abc_TruthStoreAlloc(nVars, nTruths);
+        // read info from file
+        Abc_TruthStoreRead(pFileName, p);
+    } else {
+        char * pBuffer;
+        int nFileSize = Abc_FileSize(pFileName);
+        int nBytes = (1 << (nVarNum - 3)); // why mishchencko put -3? ###
+        int nTruths = nFileSize / nBytes;
+        //Abc_Print(-2,"nFileSize=%d,nTruths=%d\n",nFileSize, nTruths);
+        if (nFileSize == -1)
+            return NULL;
+        assert(nVarNum >= 6);
+        if (nFileSize % nBytes != 0)
+            Abc_Print(0, "The file size (%d) is divided by the truth table size (%d) with remainder (%d).\n",
+                nFileSize, nBytes, nFileSize % nBytes);
+        // read file contents
+        pBuffer = Abc_FileRead(pFileName);
+        // allocate data-structure
+        p = Abc_TruthStoreAlloc2(nVarNum, nTruths, (word *) pBuffer);
+    }
+    return p;
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    [Apply decomposition to the truth table.]
+
+  Description [Returns the number of AIG nodes.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+ ***********************************************************************/
+void Abc_TruthRpoPerform(Rpo_TtStore_t * p, int nThreshold, int fVerbose) {
+    clock_t clk = clock();
+    int i;
+    int rpoCount = 0;
+    Literal_t* lit;
+    float percent;
+    for (i = 0; i < p->nFuncs; i++) {
+//        if(i>1000) {
+//            continue;
+//        }
+////        
+//        if(i!= 2196 ) { //5886
+//            continue;
+//        }
+        if(fVerbose) {
+            Abc_Print(-2,"%d: ", i+1);
+        }
+            
+        lit = Rpo_Factorize((unsigned *) p->pFuncs[i], p->nVars, nThreshold, fVerbose);
+        if (lit != NULL) {
+            if(fVerbose) {
+                Abc_Print(-2, "Solution : %s\n", lit->expression->pArray);
+                Abc_Print(-2, "\n\n");
+            }
+            Lit_Free(lit);
+            rpoCount++;
+        } else {
+            if(fVerbose) {
+                Abc_Print(-2, "null\n");
+                Abc_Print(-2, "\n\n");
+            }
+        }
+    }
+    percent = (rpoCount * 100.0) / p->nFuncs;
+    Abc_Print(-2,"%d of %d (%.2f %%) functions are RPO.\n", rpoCount,p->nFuncs,percent);
+    Abc_PrintTime(1, "Time", clock() - clk);
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Apply decomposition to truth tables.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+ ***********************************************************************/
+void Abc_TruthRpoTest(char * pFileName, int nVarNum, int nThreshold, int fVerbose) {
+    Rpo_TtStore_t * p;
+
+    // allocate data-structure
+//    if (fVerbose) {
+//        Abc_Print(-2, "Number of variables = %d\n", nVarNum);
+//    }
+    p = Abc_TtStoreLoad(pFileName, nVarNum);
+
+    if (fVerbose) {
+        Abc_Print(-2, "Number of variables = %d\n", p->nVars);
+    }
+    // consider functions from the file
+    Abc_TruthRpoPerform(p, nThreshold, fVerbose);
+
+    // delete data-structure
+    Abc_TtStoreFree(p, nVarNum);
+    //    printf( "Finished decomposing truth tables from file \"%s\".\n", pFileName );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Testbench for decomposition algorithms.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+ ***********************************************************************/
+int Abc_RpoTest(char * pFileName, int nVarNum,int nThreshold, int fVerbose) {
+    if (fVerbose) {
+        printf("Using truth tables from file \"%s\"...\n", pFileName);
+    }
+    Abc_TruthRpoTest(pFileName, nVarNum, nThreshold, fVerbose);
+    fflush(stdout);
+    return 0;
+}
+
+
+/////////////////////ert truth table to ///////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
+ABC_NAMESPACE_IMPL_END
+
+
diff --git a/src/base/abci/module.make b/src/base/abci/module.make
index c7645775..5554ea93 100644
--- a/src/base/abci/module.make
+++ b/src/base/abci/module.make
@@ -55,6 +55,7 @@ SRC +=    src/base/abci/abc.c \
     src/base/abci/abcRestruct.c \
     src/base/abci/abcResub.c \
     src/base/abci/abcRewrite.c \
+    src/base/abci/abcRpo.c \
     src/base/abci/abcRr.c \
     src/base/abci/abcSat.c \
     src/base/abci/abcScorr.c \
diff --git a/src/base/main/mainInit.c b/src/base/main/mainInit.c
index bbe0bbd1..bdf0613e 100644
--- a/src/base/main/mainInit.c
+++ b/src/base/main/mainInit.c
@@ -23,7 +23,7 @@
 
 ABC_NAMESPACE_IMPL_START
 
-//#define USE_ABC2
+#define USE_ABC2
 //#define USE_ABC85
  
 ////////////////////////////////////////////////////////////////////////
diff --git a/src/bool/rpo/literal.h b/src/bool/rpo/literal.h
new file mode 100644
index 00000000..2faf0981
--- /dev/null
+++ b/src/bool/rpo/literal.h
@@ -0,0 +1,297 @@
+/**CFile****************************************************************
+
+  FileName    [literal.h]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [RPO]
+
+  Synopsis    [Literal structure]
+
+  Author      [Mayler G. A. Martins / Vinicius Callegaro]
+  
+  Affiliation [UFRGS]
+
+  Date        [Ver. 1.0. Started - May 08, 2013.]
+
+  Revision    [$Id: literal.h,v 1.00 2013/05/08 00:00:00 mgamartins Exp $]
+
+ ***********************************************************************/
+
+#ifndef ABC__bool__rpo__literal_h
+#define ABC__bool__rpo__literal_h
+
+////////////////////////////////////////////////////////////////////////
+///                          INCLUDES                                ///
+////////////////////////////////////////////////////////////////////////
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "bool/kit/kit.h"
+#include "misc/vec/vec.h"
+#include "misc/util/abc_global.h"
+
+ABC_NAMESPACE_HEADER_START
+
+
+////////////////////////////////////////////////////////////////////////
+///                         PARAMETERS                               ///
+////////////////////////////////////////////////////////////////////////
+
+// associations
+typedef enum {
+    LIT_NONE = 0, // 0: unknown
+    LIT_AND, // 1: AND association
+    LIT_OR, // 2: OR association
+    LIT_XOR // 3: XOR association (not used yet)
+} Operator_t;
+
+
+typedef struct Literal_t_ Literal_t;
+
+struct Literal_t_ {
+    unsigned * transition;
+    unsigned * function;
+    Vec_Str_t * expression;
+};
+
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Compute the positive transition]
+
+  Description [The inputs are a function, the number of variables and a variable index and the output is a function]
+               
+  SideEffects [Should this function be in kitTruth.c ?]
+
+  SeeAlso     []
+//
+***********************************************************************/
+
+static inline void Lit_TruthPositiveTransition( unsigned * pIn, unsigned * pOut, int nVars, int varIdx )
+{
+    unsigned * cof0 = ABC_ALLOC (unsigned, Kit_TruthWordNum(nVars) );
+    unsigned * cof1 = ABC_ALLOC (unsigned, Kit_TruthWordNum(nVars) );
+    unsigned * ncof0;
+    Kit_TruthCofactor0New(cof0, pIn,nVars,varIdx);
+    Kit_TruthCofactor1New(cof1, pIn,nVars,varIdx);
+    ncof0 = ABC_ALLOC (unsigned, Kit_TruthWordNum(nVars) );
+    Kit_TruthNot(ncof0,cof0,nVars);
+    Kit_TruthAnd(pOut,ncof0,cof1, nVars);
+    ABC_FREE(cof0);
+    ABC_FREE(ncof0);
+    ABC_FREE(cof1);
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    [Compute the negative transition]
+
+  Description [The inputs are a function, the number of variables and a variable index and the output is a function]
+               
+  SideEffects [Should this function be in kitTruth.c ?]
+
+  SeeAlso     []
+
+***********************************************************************/
+
+static inline void Lit_TruthNegativeTransition( unsigned * pIn, unsigned * pOut, int nVars, int varIdx )
+{
+    unsigned * cof0 = ABC_ALLOC (unsigned, Kit_TruthWordNum(nVars) );
+    unsigned * cof1 = ABC_ALLOC (unsigned, Kit_TruthWordNum(nVars) );
+    unsigned * ncof1;
+    Kit_TruthCofactor0New(cof0, pIn,nVars,varIdx);
+    Kit_TruthCofactor1New(cof1, pIn,nVars,varIdx);
+    ncof1 = ABC_ALLOC (unsigned, Kit_TruthWordNum(nVars) );
+    Kit_TruthNot(ncof1,cof1,nVars);
+    Kit_TruthAnd(pOut,ncof1,cof0,nVars);
+    ABC_FREE(cof0);
+    ABC_FREE(cof1);
+    ABC_FREE(ncof1);
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    [Create a literal given a polarity ]
+
+  Description [The inputs are the function, index and its polarity and a the output is a literal]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+ ***********************************************************************/
+
+static inline Literal_t* Lit_Alloc(unsigned* pTruth, int nVars, int varIdx, char pol) {
+    unsigned * transition;
+    unsigned * function;
+    Vec_Str_t * exp;
+    Literal_t* lit;
+    assert(pol == '+' || pol == '-');
+    transition = ABC_ALLOC(unsigned, Kit_TruthWordNum(nVars));
+    if (pol == '+') {
+        Lit_TruthPositiveTransition(pTruth, transition, nVars, varIdx);
+    } else {
+        Lit_TruthNegativeTransition(pTruth, transition, nVars, varIdx);
+    }
+    if (!Kit_TruthIsConst0(transition,nVars)) {
+        function = ABC_ALLOC(unsigned, Kit_TruthWordNum(nVars));
+        Kit_TruthIthVar(function, nVars, varIdx);
+        //Abc_Print(-2, "Allocating function %X %d %c \n", *function, varIdx, pol);
+        exp = Vec_StrAlloc(5);
+        if (pol == '-') {
+            Kit_TruthNot(function, function, nVars);
+            Vec_StrPutC(exp, '!');
+        }
+        Vec_StrPutC(exp, (char)('a' + varIdx));
+        Vec_StrPutC(exp, '\0');
+        lit = ABC_ALLOC(Literal_t, 1);
+        lit->function = function;
+        lit->transition = transition;
+        lit->expression = exp;
+        return lit;
+    } else {
+        ABC_FREE(transition); // free the function.
+        return NULL;
+    }
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    [Group 2 literals using AND or OR]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+ ***********************************************************************/
+
+static inline Literal_t* Lit_GroupLiterals(Literal_t* lit1, Literal_t* lit2, Operator_t op, int nVars) {
+    unsigned * newFunction = ABC_ALLOC(unsigned, Kit_TruthWordNum(nVars));
+    unsigned * newTransition = ABC_ALLOC(unsigned, Kit_TruthWordNum(nVars));
+    Vec_Str_t * newExp = Vec_StrAlloc(lit1->expression->nSize + lit2->expression->nSize + 3);
+    Literal_t* newLiteral;
+    char opChar = '%';
+    switch (op) {
+        case LIT_AND:
+        {
+            //Abc_Print(-2, "Grouping AND %X %X \n", *lit1->function, *lit2->function);
+            Kit_TruthAnd(newFunction, lit1->function, lit2->function, nVars);
+            opChar = '*';
+            break;
+        }
+        case LIT_OR:
+        {
+            //Abc_Print(-2, "Grouping OR %X %X \n", *lit1->function, *lit2->function);
+            Kit_TruthOr(newFunction, lit1->function, lit2->function, nVars);
+            opChar = '+';
+            break;
+        }
+        default:
+        {
+            Abc_Print(-2, "Lit_GroupLiterals with op not defined.");
+            //TODO Call ABC Abort
+        }
+    }
+
+    Kit_TruthOr(newTransition, lit1->transition, lit2->transition, nVars);
+    // create a new expression.
+    Vec_StrPutC(newExp, '(');
+    Vec_StrAppend(newExp, lit1->expression->pArray);
+    //Vec_StrPop(newExp); // pop the \0
+    Vec_StrPutC(newExp, opChar);
+    Vec_StrAppend(newExp, lit2->expression->pArray);
+    //Vec_StrPop(newExp); // pop the \0
+    Vec_StrPutC(newExp, ')');
+    Vec_StrPutC(newExp, '\0');
+
+    newLiteral = ABC_ALLOC(Literal_t, 1);
+    newLiteral->function = newFunction;
+    newLiteral->transition = newTransition;
+    newLiteral->expression = newExp;
+    return newLiteral;
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    [Create a const literal ]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+ ***********************************************************************/
+
+static inline Literal_t* Lit_CreateLiteralConst(unsigned* pTruth, int nVars, int constant) {
+    Vec_Str_t * exp = Vec_StrAlloc(3);
+    Literal_t* lit;
+    Vec_StrPutC(exp, (char)('0' + constant));
+    Vec_StrPutC(exp, '\0');
+    lit = ABC_ALLOC(Literal_t, 1);
+    lit->expression = exp;
+    lit->function = pTruth;
+    lit->transition = pTruth; // wrong but no effect ###
+    return lit;
+}
+
+static inline Literal_t* Lit_Copy(Literal_t* lit, int nVars) {
+    Literal_t* newLit = ABC_ALLOC(Literal_t,1);
+    newLit->function = ABC_ALLOC(unsigned, Kit_TruthWordNum(nVars));
+    Kit_TruthCopy(newLit->function,lit->function,nVars);
+    newLit->transition = ABC_ALLOC(unsigned, Kit_TruthWordNum(nVars));
+    Kit_TruthCopy(newLit->transition,lit->transition,nVars);
+    newLit->expression = Vec_StrDup(lit->expression);
+//    Abc_Print(-2,"Copying: %s\n",newLit->expression->pArray); 
+    return newLit;
+}
+
+static inline void Lit_PrintTT(unsigned* tt, int nVars) {
+    int w;
+    for(w=nVars-1; w>=0; w--) {
+            Abc_Print(-2, "%08X", tt[w]);
+    }
+}
+
+static inline void Lit_PrintExp(Literal_t* lit) {
+    Abc_Print(-2, "%s", lit->expression->pArray);
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Delete the literal ]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+ ***********************************************************************/
+
+static inline void Lit_Free(Literal_t * lit) {
+    if(lit == NULL) {
+        return;
+    }
+//    Abc_Print(-2,"Freeing: %s\n",lit->expression->pArray); 
+    ABC_FREE(lit->function);
+    ABC_FREE(lit->transition);
+    Vec_StrFree(lit->expression);
+    ABC_FREE(lit);
+}
+
+ABC_NAMESPACE_HEADER_END
+
+#endif    /* LITERAL_H */
+
diff --git a/src/bool/rpo/module.make b/src/bool/rpo/module.make
new file mode 100644
index 00000000..5c07110c
--- /dev/null
+++ b/src/bool/rpo/module.make
@@ -0,0 +1 @@
+SRC +=    src/bool/rpo/rpo.c
\ No newline at end of file
diff --git a/src/bool/rpo/rpo.c b/src/bool/rpo/rpo.c
new file mode 100644
index 00000000..5311e107
--- /dev/null
+++ b/src/bool/rpo/rpo.c
@@ -0,0 +1,383 @@
+/**CFile****************************************************************
+
+  FileName    [rpo.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [RPO]
+
+  Synopsis    [Performs read polarity once factorization.]
+
+  Author      [Mayler G. A. Martins / Vinicius Callegaro]
+  
+  Affiliation [UFRGS]
+
+  Date        [Ver. 1.0. Started - May 08, 2013.]
+
+  Revision    [$Id: rpo.c,v 1.00 2013/05/08 00:00:00 mgamartins Exp $]
+
+ ***********************************************************************/
+
+#include <stdio.h>
+
+#include "literal.h"
+#include "rpo.h"
+#include "bool/kit/kit.h"
+#include "misc/util/abc_global.h"
+#include "misc/vec/vec.h"
+
+
+ABC_NAMESPACE_IMPL_START
+
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+
+typedef struct Rpo_Man_t_ Rpo_Man_t;
+
+struct Rpo_Man_t_ {
+    unsigned * target;
+    int nVars;
+
+    Literal_t ** literals;
+    int nLits;
+    int nLitsMax;
+
+    Rpo_LCI_Edge_t* lci;
+    int nLCIElems;
+
+    int thresholdMax;
+
+};
+
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Check if two literals are AND-grouped]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+ ***********************************************************************/
+int Rpo_CheckANDGroup(Literal_t* lit1, Literal_t* lit2, int nVars) {
+    unsigned* notLit1Func = ABC_ALLOC(unsigned, Kit_TruthWordNum(nVars));
+    unsigned* notLit2Func = ABC_ALLOC(unsigned, Kit_TruthWordNum(nVars));
+    unsigned* and1;
+    unsigned* and2;
+    int isZero;
+
+    Kit_TruthNot(notLit1Func, lit1->function, nVars);
+    Kit_TruthNot(notLit2Func, lit2->function, nVars);
+    and1 = ABC_ALLOC(unsigned, Kit_TruthWordNum(nVars));
+    and2 = ABC_ALLOC(unsigned, Kit_TruthWordNum(nVars));
+    Kit_TruthAnd(and1, lit1->transition, notLit2Func, nVars);
+    isZero = Kit_TruthIsConst0(and1, nVars);
+    if (isZero) {
+        Kit_TruthAnd(and2, lit2->transition, notLit1Func, nVars);
+        isZero = Kit_TruthIsConst0(and2, nVars);
+    }
+    ABC_FREE(notLit1Func);
+    ABC_FREE(notLit2Func);
+    ABC_FREE(and1);
+    ABC_FREE(and2);
+    return isZero;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Check if two literals are AND-grouped]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+ ***********************************************************************/
+int Rpo_CheckORGroup(Literal_t* lit1, Literal_t* lit2, int nVars) {
+    unsigned* and1 = ABC_ALLOC(unsigned, Kit_TruthWordNum(nVars));
+    unsigned* and2 = ABC_ALLOC(unsigned, Kit_TruthWordNum(nVars));
+    int isZero;
+    Kit_TruthAnd(and1, lit1->transition, lit2->function, nVars);
+    isZero = Kit_TruthIsConst0(and1, nVars);
+    if (isZero) {
+        Kit_TruthAnd(and2, lit2->transition, lit1->function, nVars);
+        isZero = Kit_TruthIsConst0(and2, nVars);
+    }
+    ABC_FREE(and1);
+    ABC_FREE(and2);
+    return isZero;
+}
+
+Rpo_LCI_Edge_t* Rpo_CreateEdge(Operator_t op, int i, int j, int* vertexDegree) {
+    Rpo_LCI_Edge_t* edge = ABC_ALLOC(Rpo_LCI_Edge_t, 1);
+    edge->connectionType = op;
+    edge->idx1 = i;
+    edge->idx2 = j;
+    edge->visited = 0;
+    vertexDegree[i]++;
+    vertexDegree[j]++;
+    return edge;
+}
+
+int Rpo_computeMinEdgeCost(Rpo_LCI_Edge_t** edges, int edgeCount, int* vertexDegree) {
+    int minCostIndex = -1;
+    int minVertexIndex = -1;
+    unsigned int minCost = ~0;
+    Rpo_LCI_Edge_t* edge;
+    unsigned int edgeCost;
+    int minVertex;
+    int i;
+    for (i = 0; i < edgeCount; ++i) {
+        edge = edges[i];
+        if (!edge->visited) {
+            edgeCost = vertexDegree[edge->idx1] + vertexDegree[edge->idx2];
+            minVertex = (edge->idx1 < edge->idx2) ? edge->idx1 : edge->idx2;
+            if (edgeCost < minCost) {
+                minCost = edgeCost;
+                minCostIndex = i;
+                minVertexIndex = minVertex;
+            } else if ((edgeCost == minCost) && minVertex < minVertexIndex) {
+                minCost = edgeCost;
+                minCostIndex = i;
+                minVertexIndex = minVertex;
+            }
+        }
+    }
+    return minCostIndex;
+}
+
+void Rpo_PrintEdge(Rpo_LCI_Edge_t* edge) {
+    Abc_Print(-2, "Edge (%d,%d)/%d\n", edge->idx1, edge->idx2, edge->connectionType);
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Test]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+ ***********************************************************************/
+Literal_t* Rpo_Factorize(unsigned* target, int nVars, int nThreshold, int verbose) {
+
+    int nLitCap = nVars * 2;
+    int nLit = 0;
+    int w;
+    Literal_t** vecLit;
+    Literal_t* lit;
+    Literal_t* result;
+    int thresholdCount = 0;
+
+    if (Kit_TruthIsConst0(target, nVars)) {
+        return Lit_CreateLiteralConst(target, nVars, 0);
+    } else if (Kit_TruthIsConst1(target, nVars)) {
+        return Lit_CreateLiteralConst(target, nVars, 1);
+    }
+
+    //    if (nThreshold == -1) {
+    //        nThreshold = nLitCap + nVars;
+    //    }
+    if (verbose) {
+        Abc_Print(-2, "Target: ");
+        Lit_PrintTT(target, nVars);
+        Abc_Print(-2, "\n");
+    }
+    vecLit = ABC_ALLOC(Literal_t*, nLitCap);
+
+    for (w = nVars - 1; w >= 0; w--) {
+        lit = Lit_Alloc(target, nVars, w, '+');
+        if (lit != NULL) {
+            vecLit[nLit] = lit;
+            nLit++;
+        }
+        lit = Lit_Alloc(target, nVars, w, '-');
+        if (lit != NULL) {
+            vecLit[nLit] = lit;
+            nLit++;
+        }
+    }
+    if (verbose) {
+        Abc_Print(-2, "Allocated %d literal clusters\n", nLit);
+    }
+
+    result = Rpo_Recursion(target, vecLit, nLit, nLit, nVars, &thresholdCount, nThreshold, verbose);
+
+    //freeing the memory
+    for (w = 0; w < nLit; ++w) {
+        Lit_Free(vecLit[w]);
+    }
+    ABC_FREE(vecLit);
+
+    return result;
+
+}
+
+Literal_t* Rpo_Recursion(unsigned* target, Literal_t** vecLit, int nLit, int nLitCount, int nVars, int* thresholdCount, int thresholdMax, int verbose) {
+    int i, j, k;
+    Literal_t* copyResult;
+    int* vertexDegree;
+    int v;
+    int edgeSize;
+    Rpo_LCI_Edge_t** edges;
+    int edgeCount = 0;
+    int isAnd;
+    int isOr;
+    Rpo_LCI_Edge_t* edge;
+    Literal_t* result = NULL;
+    int edgeIndex;
+    int minLitIndex;
+    int maxLitIndex;
+    Literal_t* oldLit1;
+    Literal_t* oldLit2;
+    Literal_t* newLit;
+
+    *thresholdCount = *thresholdCount + 1;
+    if (*thresholdCount == thresholdMax) {
+        return NULL;
+    }
+    if (verbose) {
+        Abc_Print(-2, "Entering recursion %d\n", *thresholdCount);
+    }
+    // verify if solution is the target or not
+    if (nLitCount == 1) {
+        if (verbose) {
+            Abc_Print(-2, "Checking solution: ");
+        }
+        for (k = 0; k < nLit; ++k) {
+            if (vecLit[k] != NULL) {
+                if (Kit_TruthIsEqual(target, vecLit[k]->function, nVars)) {
+                    copyResult = Lit_Copy(vecLit[k], nVars);
+                    if (verbose) {
+                        Abc_Print(-2, "FOUND!\n", thresholdCount);
+                    }
+                    thresholdCount = 0; //??
+                    return copyResult;
+                }
+            }
+        }
+        if (verbose) {
+            Abc_Print(-2, "FAILED!\n", thresholdCount);
+        }
+        return NULL;
+    }
+
+    vertexDegree = ABC_ALLOC(int, nLit);
+    //    if(verbose) {
+    //        Abc_Print(-2,"Allocating vertexDegree...\n");
+    //    }
+    for (v = 0; v < nLit; v++) {
+        vertexDegree[v] = 0;
+    }
+    // building edges
+    edgeSize = (nLit * (nLit - 1)) / 2;
+    edges = ABC_ALLOC(Rpo_LCI_Edge_t*, edgeSize);
+    if (verbose) {
+        Abc_Print(-2, "Creating Edges: \n");
+    }
+
+    for (i = 0; i < nLit; ++i) {
+        if (vecLit[i] == NULL) {
+            continue;
+        }
+        for (j = i; j < nLit; ++j) {
+            if (vecLit[j] == NULL) {
+                continue;
+            }
+            isAnd = Rpo_CheckANDGroup(vecLit[i], vecLit[j], nVars);
+            isOr = Rpo_CheckORGroup(vecLit[i], vecLit[j], nVars);
+            if (isAnd) {
+                if (verbose) {
+                    Abc_Print(-2, "Grouped: ");
+                    Lit_PrintExp(vecLit[j]);
+                    Abc_Print(-2, " AND ");
+                    Lit_PrintExp(vecLit[i]);
+                    Abc_Print(-2, "\n");
+                }
+                // add edge
+                edge = Rpo_CreateEdge(LIT_AND, i, j, vertexDegree);
+                edges[edgeCount++] = edge;
+            }
+            if (isOr) {
+                if (verbose) {
+                    Abc_Print(-2, "Grouped: ");
+                    Lit_PrintExp(vecLit[j]);
+                    Abc_Print(-2, " OR ");
+                    Lit_PrintExp(vecLit[i]);
+                    Abc_Print(-2, "\n");
+                }
+                // add edge
+                edge = Rpo_CreateEdge(LIT_OR, i, j, vertexDegree);
+                edges[edgeCount++] = edge;
+            }
+        }
+    }
+    if (verbose) {
+        Abc_Print(-2, "%d edges created.\n", edgeCount);
+    }
+
+
+    //traverse the edges, grouping new Literal Clusters
+    do {
+        edgeIndex = Rpo_computeMinEdgeCost(edges, edgeCount, vertexDegree);
+        if (edgeIndex < 0) {
+            if (verbose) {
+                Abc_Print(-2, "There is no edges unvisited... Exiting recursion.\n");
+                //exit(-1);
+            }
+            break;
+            //return NULL; // the graph does not have unvisited edges
+        }
+        edge = edges[edgeIndex];
+        edge->visited = 1;
+        //Rpo_PrintEdge(edge);
+        minLitIndex = (edge->idx1 < edge->idx2) ? edge->idx1 : edge->idx2;
+        maxLitIndex = (edge->idx1 > edge->idx2) ? edge->idx1 : edge->idx2;
+        oldLit1 = vecLit[minLitIndex];
+        oldLit2 = vecLit[maxLitIndex];
+        newLit = Lit_GroupLiterals(oldLit1, oldLit2, edge->connectionType, nVars);
+        vecLit[minLitIndex] = newLit;
+        vecLit[maxLitIndex] = NULL;
+
+        if (verbose) {
+            Abc_Print(-2, "New Literal Cluster found: ");
+            Lit_PrintExp(newLit);
+            Abc_Print(-2, " -> ");
+            Lit_PrintTT(newLit->function, nVars);
+            Abc_Print(-2, "\n");
+        }
+        result = Rpo_Recursion(target, vecLit, nLit, (nLitCount - 1), nVars, thresholdCount, thresholdMax, verbose);
+        //independent of result, free the newLit and restore the vector of Literal Clusters
+        Lit_Free(newLit);
+        vecLit[minLitIndex] = oldLit1;
+        vecLit[maxLitIndex] = oldLit2;
+        if (*thresholdCount == thresholdMax) {
+            break;
+        }
+    } while (result == NULL);
+    //freeing memory
+    //    if(verbose) {
+    //        Abc_Print(-2,"Freeing vertexDegree...\n");
+    //    }
+    ABC_FREE(vertexDegree);
+    for (i = 0; i < edgeCount; ++i) {
+        //Abc_Print(-2, "%p ", edges[i]);
+        ABC_FREE(edges[i]);
+    }
+    ABC_FREE(edges);
+    return result;
+}
+
+ABC_NAMESPACE_IMPL_END
\ No newline at end of file
diff --git a/src/bool/rpo/rpo.h b/src/bool/rpo/rpo.h
new file mode 100644
index 00000000..08f4a479
--- /dev/null
+++ b/src/bool/rpo/rpo.h
@@ -0,0 +1,57 @@
+/**CFile****************************************************************
+
+  FileName    [rpo.h]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [RPO]
+
+  Synopsis    [Rpo Header]
+
+  Author      [Mayler G. A. Martins / Vinicius Callegaro]
+  
+  Affiliation [UFRGS]
+
+  Date        [Ver. 1.0. Started - May 08, 2013.]
+
+  Revision    [$Id: rpo.h,v 1.00 2013/05/08 00:00:00 mgamartins Exp $]
+
+***********************************************************************/
+ 
+#ifndef ABC__bool__rpo__rpo_h
+#define ABC__bool__rpo__rpo_h
+
+////////////////////////////////////////////////////////////////////////
+///                          INCLUDES                                ///
+////////////////////////////////////////////////////////////////////////
+
+#include "literal.h"
+
+ABC_NAMESPACE_HEADER_START
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+typedef struct Rpo_LCI_Edge_t_ Rpo_LCI_Edge_t;
+
+struct Rpo_LCI_Edge_t_ {
+    unsigned long visited : 1;
+    unsigned long connectionType : 2;
+    unsigned long reserved : 1;
+    unsigned long idx1 : 30;
+    unsigned long idx2 : 30;
+};
+
+void Rpo_PrintEdge(Rpo_LCI_Edge_t* edge);
+int Rpo_CheckANDGroup(Literal_t* lit1, Literal_t* lit2, int nVars);
+int Rpo_CheckORGroup(Literal_t* lit1, Literal_t* lit2, int nVars);
+Literal_t* Rpo_Factorize(unsigned* target, int nVars, int nThreshold, int verbose);
+Literal_t* Rpo_Recursion(unsigned* target, Literal_t** vecLit, int nLit, int nLitCount, int nVars, int* thresholdCount, int thresholdMax, int verbose);
+Rpo_LCI_Edge_t* Rpo_CreateEdge(Operator_t op, int i, int j, int* vertexDegree);
+int Rpo_computeMinEdgeCost(Rpo_LCI_Edge_t** edges, int edgeCount, int* vertexDegree);
+
+ABC_NAMESPACE_HEADER_END
+        
+#endif
+  
\ No newline at end of file