diff --git a/packages/cplint/approx/bestfirst.pl b/packages/cplint/approx/bestfirst.pl
index 8f5cf20ee..f7c162f83 100644
--- a/packages/cplint/approx/bestfirst.pl
+++ b/packages/cplint/approx/bestfirst.pl
@@ -15,7 +15,7 @@
 :- use_module(library(system)).
 :- use_module(library(ugraphs)).
 :- use_module(params).
-:- use_module(tptreefile).
+:- use_module(tptree_lpad).
 :- use_module(utility).
 
 % :- source.
diff --git a/packages/cplint/approx/bestk.pl b/packages/cplint/approx/bestk.pl
index 7a47c8fd5..c71f8321f 100644
--- a/packages/cplint/approx/bestk.pl
+++ b/packages/cplint/approx/bestk.pl
@@ -15,7 +15,7 @@
 :- use_module(library(system)).
 :- use_module(library(ugraphs)).
 :- use_module(params).
-:- use_module(tptreefile).
+:- use_module(tptree_lpad).
 :- use_module(utility).
 
 % :- source.
diff --git a/packages/cplint/approx/deepdyn.pl b/packages/cplint/approx/deepdyn.pl
index 8bdb8b981..ced734864 100644
--- a/packages/cplint/approx/deepdyn.pl
+++ b/packages/cplint/approx/deepdyn.pl
@@ -15,7 +15,7 @@
 :- use_module(library(system)).
 :- use_module(library(ugraphs)).
 :- use_module(params).
-:- use_module(tptreefile).
+:- use_module(tptree_lpad).
 :- use_module(utility).
 
 % :- source.
diff --git a/packages/cplint/approx/deepit.pl b/packages/cplint/approx/deepit.pl
index 52c71047c..585351aba 100644
--- a/packages/cplint/approx/deepit.pl
+++ b/packages/cplint/approx/deepit.pl
@@ -15,7 +15,7 @@
 :- use_module(library(system)).
 :- use_module(library(ugraphs)).
 :- use_module(params).
-:- use_module(tptreefile).
+:- use_module(tptree_lpad).
 :- use_module(utility).
 
 % :- source.
diff --git a/packages/cplint/approx/exact.pl b/packages/cplint/approx/exact.pl
index ead21b34c..c7decaa11 100644
--- a/packages/cplint/approx/exact.pl
+++ b/packages/cplint/approx/exact.pl
@@ -15,7 +15,7 @@
 :- use_module(library(system)).
 :- use_module(library(ugraphs)).
 :- use_module(params).
-:- use_module(tptreefile).
+:- use_module(tptree_lpad).
 :- use_module(utility).
 
 % :- source.
diff --git a/packages/cplint/approx/simplecuddLPADs/ProblogBDD.c b/packages/cplint/approx/simplecuddLPADs/ProblogBDD.c
index 269ae533d..a472d5c8d 100644
--- a/packages/cplint/approx/simplecuddLPADs/ProblogBDD.c
+++ b/packages/cplint/approx/simplecuddLPADs/ProblogBDD.c
@@ -141,6 +141,13 @@
 *         The End                                                              *
 *                                                                              *
 \******************************************************************************/
+/* modified by Fabrizio Riguzzi in 2009 for dealing with multivalued variables:
+instead of variables or their negation, the script can contain equations of the 
+form
+variable=value
+Multivalued variables are translated to binary variables by means of a log 
+encodimg
+*/
 
 
 #include "simplecudd.h"
@@ -717,31 +724,17 @@ so that it is not recomputed
   double value;
 
 
-  //printf("Prob node %d\n",node);
-  //index=Cudd_NodeReadIndex(node);
-  //printf("Prob INdex %d\n",index);
   if (Cudd_IsConstant(node))
   {
-    value=Cudd_V(node);//node->type.value;
-    //printf("Value %e comp %d\n",value,comp);
-    if (comp)//Cudd_IsComplement(node))
-    	//return (1.0-value);
-	//if (value>0)
+    value=Cudd_V(node);
+    if (comp)
 	{
-//	printf("return 0");
 	return 0.0;
 	}
 	else
 	{
-//	printf("return 1");
 	return 1.0;
 	}
-/*else
-	if (value>0)
-	return 1.0;
-	else
-	return 0.0;
-*/    //return value;
   }
   else
 {
@@ -749,22 +742,15 @@ so that it is not recomputed
 	
 	if (Found!=NULL)
 	{
-	//printf("value found %e\n",Found->dvalue);
 		return Found->dvalue;
 	}
 	else
   	{
 		index=Cudd_NodeReadIndex(node);
-		//printf("node absent %d comp %d\n",node,comp);
-    		//mVarIndex=array_fetch(int,bVar2mVar,index);
 		mVarIndex=MyManager.varmap.bVar2mVar[index];
-    		//v=array_fetch(variable,vars,mVarIndex);
 		v=MyManager.varmap.mvars[mVarIndex];
     		nBit=v.nBit;
-//		printf("calling prob bool mvar %d nbit %d\n",mVarIndex,nBit);
-		//scanf("%d",&r);
     		res=ProbBool(MyManager,node,0,nBit,0,v,comp);
-		//printf("New val %e\n",res);
 		AddNode1(MyManager.varmap.bVar2mVar,MyManager.his, MyManager.varmap.varstart, node, res, 0, NULL);
     		return res;
   	}
@@ -778,68 +764,40 @@ double ProbBool(extmanager MyManager, DdNode *node, int bits, int nBit,int posBV
   double p,res;
   double * probs;
   int index;
-// printf("ProbBool nBit %d\n",nBit); 
- //scanf("%d",&r);
   probs=v.probabilities;
   if (nBit==0)
   {
-  	//printf("last var bits %d larray %d comp %d\n",bits,array_n(probs),comp);
-//	printf("bits %d v.nbit %d\n",bits,v.nBit);
     if (bits>=v.nVal)
-   	//if (comp)
 	{
-	//printf("bits>=v.nbit return 0\n"); 
 	return 0.0;
 	}
-	//else
-      //{printf("return 0\n");
-      //return 1.0;}}
     else
     {
-     // printf("Val %d\n",bits);
-
-      //p=array_fetch(double,probs,bits);
       p=probs[bits];
-      //printf("prob %e\n",p);
       res=p*Prob(MyManager,node,comp);
-      //printf("prob %e\n",p);
-      //printf("bottom %e\n",res);
       return res;
     }
   }
   else
   {
-    //if (correctPosition(node->index,v,node,posBVar))
     index=Cudd_NodeReadIndex(node);
-    //printf("index %d\n",Cudd_NodeReadIndex(node));
      if (correctPosition(index,v,posBVar))
     {
-      //printf("node %d\n",node);
-      T = Cudd_T(node);//node->type.kids.T;
-      F = Cudd_E(node);//node->type.kids.E;
+      T = Cudd_T(node);
+      F = Cudd_E(node);
       bits=bits<<1;
-      //printf("calling on the true child %di complement %d\n",T,Cudd_IsComplement(T));
       res=ProbBool(MyManager,T,bits+1,nBit-1,posBVar+1,v,comp);
-      //printf("res %e\ncalling on the else child %d c %d\n",res,F,Cudd_IsComplement(F));
-      //printf("comp %d ",comp);
       comp=(!comp && Cudd_IsComplement(F)) || (comp && !Cudd_IsComplement(F));
-      //printf("comp %d \n",comp);
 res=res+ 
         ProbBool(MyManager,F,bits,nBit-1,posBVar+1,v,comp);
-	//printf("res 2 %e\n",res);
       return res;
     }
     else
     {
-     //printf("absent var\n"); 
       bits=bits<<1;
-     // printf("Var =1\n");
       res=ProbBool(MyManager,node,bits+1,nBit-1,posBVar+1,v,comp);
-      //printf("res 1 %e\n",res);
-//printf("var =0\n");
       res=res+ 
         ProbBool(MyManager,node,bits,nBit-1,posBVar+1,v,comp);
-    //  printf("res 2 %e\n",res);
 return res;
     }
   }
@@ -850,12 +808,8 @@ int correctPosition(int index,variable v,int posBVar)
 currently explored by ProbBool */
 {
   int bvar;
-//printf("posbvar %d\n",posBVar);
-//printf("length %d\n",array_n(v.booleanVars));
-  //bvar=array_fetch(DdNode *,v.booleanVars,posBVar);
   bvar=v.booleanVars[posBVar];
 
- // return  var->index==index;
 return(bvar==index);
 }
 
diff --git a/packages/cplint/approx/simplecuddLPADs/general.c b/packages/cplint/approx/simplecuddLPADs/general.c
index 64a7f88e1..fd1d01fb4 100644
--- a/packages/cplint/approx/simplecuddLPADs/general.c
+++ b/packages/cplint/approx/simplecuddLPADs/general.c
@@ -140,6 +140,11 @@
 *         The End                                                              *
 *                                                                              *
 \******************************************************************************/
+/* modified by Fabrizio Riguzzi in 2009 for dealing with multivalued variables
+instead of variables or their negation, the script can contain equations of the 
+form
+variable=value
+*/
 
 
 #include "general.h"
diff --git a/packages/cplint/approx/simplecuddLPADs/general.h b/packages/cplint/approx/simplecuddLPADs/general.h
index 4441ed623..4411092e4 100644
--- a/packages/cplint/approx/simplecuddLPADs/general.h
+++ b/packages/cplint/approx/simplecuddLPADs/general.h
@@ -140,6 +140,11 @@
 *         The End                                                              *
 *                                                                              *
 \******************************************************************************/
+/* modified by Fabrizio Riguzzi in 2009 for dealing with multivalued variables
+instead of variables or their negation, the script can contain equations of the 
+form
+variable=value
+*/
 
 
 #include <stdio.h>
diff --git a/packages/cplint/approx/simplecuddLPADs/simplecudd.c b/packages/cplint/approx/simplecuddLPADs/simplecudd.c
index e361aeb91..52667ff3c 100644
--- a/packages/cplint/approx/simplecuddLPADs/simplecudd.c
+++ b/packages/cplint/approx/simplecuddLPADs/simplecudd.c
@@ -140,8 +140,11 @@
 *         The End                                                              *
 *                                                                              *
 \******************************************************************************/
-
-
+/* modified by Fabrizio Riguzzi in 2009 for dealing with multivalued variables
+instead of variables or their negation, the script can contain equations of the 
+form
+variable=value
+*/
 #include "simplecudd.h"
 
 /* BDD manager initialization */
@@ -587,7 +590,6 @@ int LoadMultiVariableData(DdManager * mgr,namedvars varmap, char *filename) {
         varname = (char *) malloc(sizeof(char) * strlen(dataread));
         strcpy(varname, dataread);
 	varmap.vars[index]=varname;
-	//printf("vname %d %s\n",index, varmap.vars[index]);
 
 	fscanf(data, "%d\n", &values);
 			varmap.loaded[index] = 1;
@@ -767,7 +769,6 @@ int AddNamedMultiVar(DdManager *mgr,namedvars varmap, const char *varname, int *
   int *booleanVars;
   char * vname;
   l=strlen(varname);
-  //printf("addnamed %s\n",varname);
   i=0;
 	while (varname[i]!='-')
 	{
@@ -776,11 +777,8 @@ int AddNamedMultiVar(DdManager *mgr,namedvars varmap, const char *varname, int *
 	vname=(char *)malloc(sizeof(char)*(l+1));
 	strncpy(vname,varname,i);
 	vname[i]='\0';
-	//printf("addnamed vname %s\n",vname);
 	sscanf(varname+i+1,"%d",value);
   index= GetNamedVarIndex(varmap, vname);
-  //printf("index %d\n",index);
-  //printf("init %d\n",varmap.mvars[index].init);
   if (index == -1 * varmap.varcnt) {
     return -1;
   } else if ((index < 0) || (index == 0 && varmap.vars[0] == NULL)) {
@@ -790,16 +788,14 @@ int AddNamedMultiVar(DdManager *mgr,namedvars varmap, const char *varname, int *
   if (varmap.mvars[index].init==0){
   nBit=varmap.mvars[index].nBit;
   booleanVars= varmap.mvars[index].booleanVars;
-  //Cudd_MakeTreeNode(mgr,boolVars,nBit,MTR_FIXED);
   for (i=0;i<nBit;i++)
 {
-	//printf("index %d %d bv %d\n",index,i,boolVars);
 	booleanVars[i]=boolVars;
 	varmap.bVar2mVar[boolVars]=index;
 	boolVars=boolVars+1;
 }
 varmap.mvars[index].init=1;
-} //else  printf("index found %d %d bv %d\n",index,i,varmap.mvars[index].booleanVars[0]);
+} 
   return index;
 }
 
@@ -854,7 +850,6 @@ int SetNamedVarValues(namedvars varmap, const char *varname, double dvalue, int
 int GetNamedVarIndex(const namedvars varmap, const char *varname) {
   int i,j;
   for (i = 0; i < varmap.varcnt; i++) {
-  //	printf(" %d %s %s\n",i,varmap.vars[i],varname);
     if (varmap.vars[i] == NULL) return -1 * i;
     if (strcmp(varmap.vars[i], varname) == 0) return i;
   }
@@ -969,11 +964,9 @@ DdNode* FileGenerateBDD(DdManager *manager, namedvars varmap, bddfileheader file
             Line = LineParser(manager, varmap, inter, fileheader.intercnt, inputline, iline);
 	endAt = clock();
 	secs = ((double) (endAt - startAt)) / ((double) CLOCKS_PER_SEC)*1000;
-	//printf("line %e\n",secs);
           } else {
             interfileheader = ReadFileHeader(filename);
             if (interfileheader.inputfile == NULL) {
-              //Line = simpleBDDload(manager, &varmap, filename);
               Line = NULL;
             } else {
               Line = FileGenerateBDD(manager, varmap, interfileheader);
@@ -1113,9 +1106,7 @@ DdNode* LineParser(DdManager *manager, namedvars varmap, DdNode **inter, int max
           inegvar = 1;
         } else {
           iconst = 0;
-	  //printf("term %s\n",term + inegvar);
           ivar = AddNamedMultiVar(manager,varmap, term + inegvar,&value);
-  	//printf("term %s var %d\n",term + inegvar,ivar);
 
           if (ivar == -1) {
             fprintf(stderr, "Line Parser Error at line: %i. More BDD variables than the reserved term: %s.\n", iline, term);
diff --git a/packages/cplint/approx/simplecuddLPADs/simplecudd.h b/packages/cplint/approx/simplecuddLPADs/simplecudd.h
index 998ad182b..92d19ad7e 100644
--- a/packages/cplint/approx/simplecuddLPADs/simplecudd.h
+++ b/packages/cplint/approx/simplecuddLPADs/simplecudd.h
@@ -140,6 +140,11 @@
 *         The End                                                              *
 *                                                                              *
 \******************************************************************************/
+/* modified by Fabrizio Riguzzi in 2009 for dealing with multivalued variables
+instead of variables or their negation, the script can contain equations of the 
+form
+variable=value
+*/
 
 
 #include <stdio.h>
diff --git a/packages/cplint/approx/tptree_lpad.pl b/packages/cplint/approx/tptree_lpad.pl
index d0e724167..d3db013b9 100644
--- a/packages/cplint/approx/tptree_lpad.pl
+++ b/packages/cplint/approx/tptree_lpad.pl
@@ -6,8 +6,14 @@
 % remembers shortest prefix of a conjunction only (i.e. a*b+a*b*c results in a*b only, but b*a+a*b*c is not reduced)
 % children are sorted, but branches aren't (to speed up search while keeping structure sharing from proof procedure)
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+/* derived from tptree.yap from ProbLog by Fabrizio Riguzzi in 2009 
+for dealing with multivalued variables
+instead of variables or their negation, the script can contain equations of the 
+form
+variable=value
+*/
 
-:- module(ptree,[init_ptree/1,
+:- module(ptree_lpad,[init_ptree/1,
 	delete_ptree/1,
 	rename_ptree/2,
 	member_ptree/2,