cudd/nanotrav/ntrBddTest.c

/**
  @file

  @ingroup nanotrav

  @brief %BDD test functions for the nanotrav program.

  @author Fabio Somenzi

  @copyright@parblock
  Copyright (c) 1995-2015, Regents of the University of Colorado

  All rights reserved.

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions
  are met:

  Redistributions of source code must retain the above copyright
  notice, this list of conditions and the following disclaimer.

  Redistributions in binary form must reproduce the above copyright
  notice, this list of conditions and the following disclaimer in the
  documentation and/or other materials provided with the distribution.

  Neither the name of the University of Colorado nor the names of its
  contributors may be used to endorse or promote products derived from
  this software without specific prior written permission.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  POSSIBILITY OF SUCH DAMAGE.
  @endparblock

*/

#include "ntr.h"
#include "cuddInt.h"

/*---------------------------------------------------------------------------*/
/* Constant declarations                                                     */
/*---------------------------------------------------------------------------*/

/*---------------------------------------------------------------------------*/
/* Stucture declarations                                                     */
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/* Type declarations                                                         */
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/*---------------------------------------------------------------------------*/
/* Variable declarations                                                     */
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/*---------------------------------------------------------------------------*/
/* Macro declarations                                                        */
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/** \cond */

/*---------------------------------------------------------------------------*/
/* Static function prototypes                                                */
/*---------------------------------------------------------------------------*/

static int ntrTestMinimizationAux (DdManager *dd, BnetNetwork *net1, DdNode *f, char *name, DdNode *c, char *cname, NtrOptions *option);
static int ntrTestDensityAux (DdManager *dd, BnetNetwork *net, DdNode *f, char *name, NtrOptions *option);
static int ntrTestDecompAux (DdManager *dd, BnetNetwork *net, DdNode *f, char *name, NtrOptions *option);
static int ntrTestCofEstAux (DdManager * dd, BnetNetwork * net, DdNode * f, char * name, NtrOptions * option);
static int ntrTestClippingAux (DdManager *dd, BnetNetwork *net1, DdNode *f, char *name, DdNode *g, char *gname, NtrOptions *option);
static int ntrTestEquivAndContainAux (DdManager *dd, BnetNetwork *net1, DdNode *f, char *fname, DdNode *g, char *gname, DdNode *d, char *dname, NtrOptions *option);
static int ntrTestClosestCubeAux (DdManager *dd, BnetNetwork *net, DdNode *f, char *fname, DdNode *g, char *gname, DdNode **vars, NtrOptions *option);
static int ntrTestCharToVect(DdManager * dd, DdNode * f, NtrOptions *option);
#if 0
static DdNode * ntrCompress1 (DdManager *dd, DdNode *f, int nvars, int threshold);
#endif
static DdNode * ntrCompress2 (DdManager *dd, DdNode *f, int nvars, int threshold);
static BnetNode * ntrNodeIsBuffer (BnetNode *nd, st_table *hash);

/** \endcond */


/*---------------------------------------------------------------------------*/
/* Definition of exported functions                                          */
/*---------------------------------------------------------------------------*/


/**
  @brief Tests %BDD minimization functions.

  @details Tests %BDD minimization functions, including
  leaf-identifying compaction, squeezing, and restrict. This function
  uses as constraint the first output of net2 and computes positive
  and negative cofactors of all the outputs of net1. For each
  cofactor, it checks whether compaction was safe (cofactor not larger
  than original function) and that the expansion based on each
  minimization function (used as a generalized cofactor) equals the
  original function.

  @return 1 if successful; 0 otherwise.

  @sideeffect None

*/
int
Ntr_TestMinimization(
  DdManager * dd,
  BnetNetwork * net1,
  BnetNetwork * net2,
  NtrOptions * option)
{
    DdNode *f;
    DdNode *c = NULL;
    char *cname = NULL;
    BnetNode *node;
    int i;
    int result;
    int nsize, csize;

    if (option->second == FALSE) return(1);

    (void) printf("Testing BDD minimization algorithms\n");
    /* Use largest output of second network as constraint. */
    csize = -1;
    for (i = 0; i < net2->noutputs; i++) {
	if (!st_lookup(net2->hash,net2->outputs[i],(void **)&node)) {
	    return(0);
	}
	nsize = Cudd_DagSize(node->dd);
	if (nsize > csize) {
	    c = node->dd;
	    cname = node->name;
	    csize = nsize;
	}
    }
    if (c == NULL || cname == NULL) return(0);
    (void) printf("TEST-MINI: Constrain (%s) %d nodes\n",
		  cname, Cudd_DagSize(c));

    if (option->node == NULL) {
	for (i = 0; i < net1->noutputs; i++) {
	    if (!st_lookup(net1->hash,net1->outputs[i],(void **)&node)) {
		return(0);
	    }
	    f = node->dd;
	    if (f == NULL) return(0);
	    result = ntrTestMinimizationAux(dd,net1,f,node->name,c,cname,
					    option);
	    if (result == 0) return(0);
	}
    } else {
	if (!st_lookup(net1->hash,option->node,(void **)&node)) {
	    return(0);
	}
	f = node->dd;
	if (f == NULL) return(0);
	result = ntrTestMinimizationAux(dd,net1,f,option->node,c,cname,option);
	if (result == 0) return(0);
    }

    return(1);

} /* end of Ntr_TestMinimization */


/**
  @brief Tests %BDD density-related functions.

  @return 1 if successful; 0 otherwise.

  @sideeffect None

*/
int
Ntr_TestDensity(
  DdManager * dd,
  BnetNetwork * net1,
  NtrOptions * option)
{
    DdNode *f;
    BnetNode *node;
    int i;
    int result;

    if (option->density == FALSE) return(1);

    (void) printf("Testing BDD density-related algorithms\n");
    if (option->node == NULL) {
	for (i = 0; i < net1->noutputs; i++) {
	    if (!st_lookup(net1->hash,net1->outputs[i],(void **)&node)) {
		return(0);
	    }
	    f = node->dd;
	    if (f == NULL) return(0);
	    result = ntrTestDensityAux(dd,net1,f,node->name,option);
	    if (result == 0) return(0);
	}
    } else {
	if (!st_lookup(net1->hash,option->node,(void **)&node)) {
	    return(0);
	}
	f = node->dd;
	if (f == NULL) return(0);
	result = ntrTestDensityAux(dd,net1,f,option->node,option);
	if (result == 0) return(0);
    }

    return(1);

} /* end of Ntr_TestDensity */


/**
  @brief Tests %BDD decomposition functions.

  @return 1 if successful; 0 otherwise.

  @sideeffect None

*/
int
Ntr_TestDecomp(
  DdManager * dd,
  BnetNetwork * net1,
  NtrOptions * option)
{
    DdNode *f;
    BnetNode *node;
    int i;
    int result;

    if (option->decomp == FALSE) return(1);

    (void) printf("Testing BDD decomposition algorithms\n");
    if (option->node == NULL) {
	for (i = 0; i < net1->noutputs; i++) {
	    if (!st_lookup(net1->hash,net1->outputs[i],(void **)&node)) {
		return(0);
	    }
	    f = node->dd;
	    if (f == NULL) return(0);
	    result = ntrTestDecompAux(dd,net1,f,node->name,option);
	    if (result == 0) return(0);
	}
    } else {
	if (!st_lookup(net1->hash,option->node,(void **)&node)) {
	    return(0);
	}
	f = node->dd;
	if (f == NULL) return(0);
	result = ntrTestDecompAux(dd,net1,f,option->node,option);
	if (result == 0) return(0);
    }

    return(1);

} /* end of ntrTestDecomp */


/**
  @brief Verify equivalence of combinational networks.

  @details The two networks are supposed to have the same names for
  inputs and outputs. The only exception is that the second network
  may miss output buffers that are present in the first network. This
  function tries to match both the output and the input of the buffer.

  @return 1 if successful and if the networks are equivalent; -1 if
  successful, but the networks are not equivalent; 0 otherwise.

  @sideeffect None

*/
int
Ntr_VerifyEquivalence(
  DdManager * dd,
  BnetNetwork * net1,
  BnetNetwork * net2,
  NtrOptions * option)
{
    BnetNode *node;
    char *oname;
    DdNode *odd1, *odd2;
    int i;
    int pr;

    (void) printf("Testing equivalence\n");
    if (net2->noutputs != net1->noutputs) {
	(void) printf("The two networks have different number of outputs\n");
	(void) printf("  %s has %d outputs\n  %s has %d outputs\n",
		      net1->name, net1->noutputs, net2->name, net2->noutputs);
	return(-1);
    }
    if (net2->nlatches != net1->nlatches) {
	(void) printf("The two networks have different number of latches\n");
	(void) printf("  %s has %d latches\n  %s has %d latches\n",
		      net1->name, net1->nlatches, net2->name, net2->nlatches);
	return(-1);
    }

    pr = option->verb;
    for (i = 0; i < net1->noutputs; i++) {
	oname = net1->outputs[i];
	if (!st_lookup(net1->hash,oname,(void **)&node)) {
	    return(0);
	}
	odd1 = node->dd;
	(void) printf("%s", oname);
	Cudd_PrintDebug(dd, node->dd, Cudd_ReadSize(dd), pr);
	if (!st_lookup(net2->hash,oname,(void **)&node)) {
	    BnetNode *inpnd;
	    if ((inpnd = ntrNodeIsBuffer(node,net1->hash)) == NULL ||
		!st_lookup(net2->hash,inpnd->name,(void **)&node)) {
		(void) printf("Output %s missing from network %s\n",
			      oname, net2->name);
		return(-1);
	    } else {
		odd2 = inpnd->dd;
	    }
	} else {
	    odd2 = node->dd;
	}
	if (odd1 != odd2) {
	    (void) printf("Output %s is not equivalent\n", oname);
	    return(-1);
	}
    }
    return(1);

} /* end of Ntr_VerifyEquivalence */


/**
  @brief Tests %BDD cofactor estimate functions.

  @return 1 if successful; 0 otherwise.

  @sideeffect None

*/
int
Ntr_TestCofactorEstimate(
  DdManager * dd,
  BnetNetwork * net,
  NtrOptions * option)
{
    DdNode *f;
    BnetNode *node;
    int i;
    int result;

    if (option->cofest == FALSE) return(1);

    (void) printf("Testing BDD cofactor estimation algorithms\n");
    if (option->node == NULL) {
	for (i = 0; i < net->noutputs; i++) {
	    if (!st_lookup(net->hash,net->outputs[i],(void **)&node)) {
		return(0);
	    }
	    f = node->dd;
	    if (f == NULL) return(0);
	    result = ntrTestCofEstAux(dd,net,f,node->name,option);
	    if (result == 0) return(0);
	}
    } else {
	if (!st_lookup(net->hash,option->node,(void **)&node)) {
	    return(0);
	}
	f = node->dd;
	if (f == NULL) return(0);
	result = ntrTestCofEstAux(dd,net,f,option->node,option);
	if (result == 0) return(0);
    }

    return(1);

} /* end of Ntr_TestCofactorEstimate */


/**
  @brief Tests %BDD clipping functions.

  @return 1 if successful; 0 otherwise.

  @sideeffect None

*/
int
Ntr_TestClipping(
  DdManager * dd,
  BnetNetwork * net1,
  BnetNetwork * net2,
  NtrOptions * option)
{
    DdNode *f;
    DdNode *g = NULL;
    char *gname = NULL;
    BnetNode *node;
    int i;
    int result;
    int nsize, gsize;

    if (option->clip < 0.0) return(1);

    (void) printf("Testing BDD clipping algorithms\n");
    /* Use largest output of second network as second operand. */
    gsize = -1;
    for (i = 0; i < net2->noutputs; i++) {
	if (!st_lookup(net2->hash,net2->outputs[i],(void **)&node)) {
	    return(0);
	}
	nsize = Cudd_DagSize(node->dd);
	if (nsize > gsize) {
	    g = node->dd;
	    gname = node->name;
	    gsize = nsize;
	}
    }
    if (g == NULL || gname == NULL) return(0);
    (void) printf("TEST-CLIP: Second operand (%s) %d nodes\n",
		  gname, Cudd_DagSize(g));

    if (option->node == NULL) {
	for (i = 0; i < net1->noutputs; i++) {
	    if (!st_lookup(net1->hash,net1->outputs[i],(void **)&node)) {
		return(0);
	    }
	    f = node->dd;
	    if (f == NULL) return(0);
	    result = ntrTestClippingAux(dd,net1,f,node->name,g,gname,option);
	    if (result == 0) return(0);
	}
    } else {
	if (!st_lookup(net1->hash,option->node,(void **)&node)) {
	    return(0);
	}
	f = node->dd;
	if (f == NULL) return(0);
	result = ntrTestClippingAux(dd,net1,f,option->node,g,gname,option);
	if (result == 0) return(0);
    }

    return(1);

} /* end of Ntr_TestClipping */


/**
  @brief Tests %BDD equivalence and containment with don't cares.

  @details Tests functions for %BDD equivalence and containment
  with don't cares, including Cudd_EquivDC and Cudd_bddLeqUnless. This
  function uses as care set the first output of net2 and checkes
  equivalence and containment for of all the output pairs of net1.

  @return 1 if successful; 0 otherwise.

  @sideeffect None

*/
int
Ntr_TestEquivAndContain(
  DdManager *dd,
  BnetNetwork *net1,
  BnetNetwork *net2,
  NtrOptions *option)
{
    DdNode *f, *g;
    DdNode *d = NULL;
    char *dname = NULL;
    BnetNode *node1, *node2;
    int i, j;
    int result;
    int nsize, dsize;

    if (option->dontcares == FALSE) return(1);

    (void) printf("Testing BDD equivalence and containment algorithms\n");
    /* Use largest output of second network as constraint. */
    dsize = -1;
    for (i = 0; i < net2->noutputs; i++) {
	if (!st_lookup(net2->hash,net2->outputs[i],(void **)&node1)) {
	    return(0);
	}
	nsize = Cudd_DagSize(node1->dd);
	if (nsize > dsize) {
	    d = node1->dd;
	    dname = node1->name;
	    dsize = nsize;
	}
    }
    if (d == NULL || dname == NULL) return(0);
    (void) printf("TEST-DC: Don't care set (%s) %d nodes\n",
		  dname, Cudd_DagSize(d));

    if (option->node == NULL) {
	for (i = 0; i < net1->noutputs; i++) {
	    if (!st_lookup(net1->hash,net1->outputs[i],(void **)&node1)) {
		return(0);
	    }
	    f = node1->dd;
	    if (f == NULL) return(0);
	    for (j = 0; j < net1->noutputs; j++) {
		if (!st_lookup(net1->hash,net1->outputs[j],(void **)&node2)) {
		    return(0);
		}
		g = node2->dd;
		if (g == NULL) return(0);
		result = ntrTestEquivAndContainAux(dd,net1,f,node1->name,g,
						   node2->name,d,dname,option);
		if (result == 0) return(0);
	    }
	}
    } else {
	if (!st_lookup(net1->hash,option->node,(void **)&node1)) {
	    return(0);
	}
	f = node1->dd;
	if (f == NULL) return(0);
	for (j = 0; j < net1->noutputs; j++) {
	    if (!st_lookup(net1->hash,net1->outputs[j],(void **)&node2)) {
		return(0);
	    }
	    g = node2->dd;
	    if (g == NULL) return(0);
	    result = ntrTestEquivAndContainAux(dd,net1,f,option->node,
					       g,node2->name,d,dname,option);
	    if (result == 0) return(0);
	}
    }

    return(1);

} /* end of Ntr_TestEquivAndContain */


/**
  @brief Tests the Cudd_bddClosestCube function.

  @return 1 if successful; 0 otherwise.

  @sideeffect None

*/
int
Ntr_TestClosestCube(
  DdManager * dd,
  BnetNetwork * net,
  NtrOptions * option)
{
    DdNode *f, *g;
    BnetNode *node1, *node2;
    int i, j, nvars;
    int result;
    DdNode **vars;
    double calls;

    if (option->closestCube == FALSE) return(1);

    (void) printf("Testing Cudd_bddClosestCube\n");
    nvars = Cudd_ReadSize(dd);
    vars = ALLOC(DdNode *, nvars);
    if (vars == NULL) return(0);
    for (i = 0; i < nvars; i++) {
	vars[i] = Cudd_bddIthVar(dd,i);
    }
    calls = Cudd_ReadRecursiveCalls(dd);
    if (option->node == NULL) {
	for (i = 0; i < net->noutputs; i++) {
	    if (!st_lookup(net->hash,net->outputs[i],(void **)&node1)) {
		FREE(vars);
		return(0);
	    }
	    f = node1->dd;
	    if (f == NULL) {
		FREE(vars);
		return(0);
	    }
	    for (j = 0; j < net->noutputs; j++) {
		if (!st_lookup(net->hash,net->outputs[j],(void **)&node2)) {
		    FREE(vars);
		    return(0);
		}
		g = node2->dd;
		if (g == NULL) {
		    FREE(vars);
		    return(0);
		}
		result = ntrTestClosestCubeAux(dd,net,f,node1->name,g,
					       node2->name,vars,option);
		if (result == 0) {
		    FREE(vars);
		    return(0);
		}
	    }
	}
    } else {
	if (!st_lookup(net->hash,option->node,(void **)&node1)) {
	    FREE(vars);
	    return(0);
	}
	f = node1->dd;
	if (f == NULL) {
	    FREE(vars);
	    return(0);
	}
	for (j = 0; j < net->noutputs; j++) {
	    if (!st_lookup(net->hash,net->outputs[j],(void **)&node2)) {
		FREE(vars);
		return(0);
	    }
	    g = node2->dd;
	    if (g == NULL) {
		FREE(vars);
		return(0);
	    }
	    result = ntrTestClosestCubeAux(dd,net,f,option->node,g,
					   node2->name,vars,option);
	    if (result == 0) {
		FREE(vars);
		return(0);
	    }
	}
    }
    (void) printf("End of test.  Performed %.0f recursive calls.\n",
		  Cudd_ReadRecursiveCalls(dd) - calls);
    FREE(vars);
    return(1);

} /* end of Ntr_TestClosestCube */


/**
  @brief Tests extraction of two-literal clauses.

  @return 1 if successful; 0 otherwise.

  @sideeffect None

*/
int
Ntr_TestTwoLiteralClauses(
  DdManager * dd,
  BnetNetwork * net1,
  NtrOptions * option)
{
    DdNode *f;
    BnetNode *node;
    int result;
    char **inames = NULL;
    int i;

    if (option->clauses == FALSE) return(1);

    /* Initialize data structures. */
    inames = ALLOC(char *,Cudd_ReadSize(dd));
    if (inames == NULL) return(0);
    for (i = 0; i < Cudd_ReadSize(dd); i++) {
	inames[i] = NULL;
    }

    /* Find the input names. */
    for (i = 0; i < net1->ninputs; i++) {
	if (!st_lookup(net1->hash,net1->inputs[i],(void **)&node)) {
	    FREE(inames);
	    return(0);
	}
	inames[node->var] = net1->inputs[i];
    }
    for (i = 0; i < net1->nlatches; i++) {
	if (!st_lookup(net1->hash,net1->latches[i][1],(void **)&node)) {
	    FREE(inames);
	    return(0);
	}
	inames[node->var] = net1->latches[i][1];
    }

    (void) printf("Testing extraction of two literal clauses\n");
    if (option->node == NULL) {
	for (i = 0; i < net1->noutputs; i++) {
	    if (!st_lookup(net1->hash,net1->outputs[i],(void **)&node)) {
		return(0);
	    }
	    f = node->dd;
	    if (f == NULL) {
		FREE(inames);
		return(0);
	    }
	    (void) printf("*** %s ***\n", net1->outputs[i]);
	    result = Cudd_PrintTwoLiteralClauses(dd, f, inames, NULL);
	    if (result == 0) {
		FREE(inames);
		return(0);
	    }
	}
    } else {
	if (!st_lookup(net1->hash,option->node,(void **)&node)) {
	    return(0);
	}
	f = node->dd;
	if (f == NULL) {
	    FREE(inames);
	    return(0);
	}
	(void) printf("*** %s ***\n", option->node);
	result = Cudd_PrintTwoLiteralClauses(dd, f, inames, NULL);
	if (result == 0) {
	    FREE(inames);
	    return(0);
	}
    }

    FREE(inames);
    return(1);

} /* end of Ntr_TestTwoLiteralClauses */


/**
  @brief Test char-to-vect conversion.

  @return 1 if successful; 0 otherwise.

  @sideeffect None

*/
int
Ntr_TestCharToVect(
  DdManager * dd,
  BnetNetwork * net1,
  NtrOptions * option)
{
    DdNode *f;
    int result;
    BnetNode *node;
    int i;

    if (option->char2vect == FALSE) return(1);

    (void) printf("Testing char-to-vect\n");
    if (net1->nlatches > 0) {
	NtrPartTR *T;
	T = Ntr_buildTR(dd,net1,option,NTR_IMAGE_MONO);
	result = ntrTestCharToVect(dd,T->part[0],option);
	Ntr_freeTR(dd,T);
    } else if (option->node == NULL) {
	result = 1;
	for (i = 0; i < net1->noutputs; i++) {
	    if (!st_lookup(net1->hash,net1->outputs[i],(void **)&node)) {
		return(0);
	    }
	    f = node->dd;
	    if (f == NULL) return(0);
	    (void) printf("*** %s ***\n", net1->outputs[i]);
	    result = ntrTestCharToVect(dd,f,option);
	    if (result == 0) return(0);
	}
    } else {
	if (!st_lookup(net1->hash,option->node,(void **)&node)) {
	    return(0);
	}
	f = node->dd;
	if (f == NULL) return(0);
	result = ntrTestCharToVect(dd,f,option);
    }
    return(result);

} /* end of Ntr_TestCharToVect */


/*---------------------------------------------------------------------------*/
/* Definition of internal functions                                          */
/*---------------------------------------------------------------------------*/

/*---------------------------------------------------------------------------*/
/* Definition of static functions                                            */
/*---------------------------------------------------------------------------*/


/**
  @brief Processes one %BDD for Ntr_TestMinimization.

  @return 1 if successful; 0 otherwise.

  @sideeffect None

  @see Ntr_TestMinimization

*/
static int
ntrTestMinimizationAux(
  DdManager * dd,
  BnetNetwork * net1,
  DdNode * f,
  char * name,
  DdNode * c,
  char * cname,
  NtrOptions * option)
{
    DdNode *com1, *com0, *min1, *min0, *sq1, *sq0;
    DdNode *rs1, *rs0, *cs1, *cs0, *na1, *na0, *a1, *a0;
    DdNode *g, *u1, *l1, *u0, *l0;
    int pr, nvars;
    int sizeF, sizeMin1, sizeMin0, sizeSq1, sizeSq0, sizeCom1, sizeCom0;
    int sizeRs1, sizeRs0, sizeCs1, sizeCs0, sizeNa1, sizeNa0, sizeA1, sizeA0;
    static char *onames[11];
    DdNode *outputs[11];
    DdNode *fc[2];

    pr = option->verb;
    fc[0] = f; fc[1] = c;
    nvars = Cudd_VectorSupportSize(dd,fc,2);
    if (nvars == CUDD_OUT_OF_MEM) return(0);
    (void) printf("TEST-MINI:: %s\n", name);
    (void) printf("T-M    ");
    Cudd_PrintDebug(dd, f, nvars, pr);
    sizeF = Cudd_DagSize(f);

    /* Compute positive generalized cofactor. */
    com1 = Cudd_bddLICompaction(dd, f, c);
    if (com1 == NULL) {
	(void) printf("TEST-MINI: LI-compaction failed (1).\n");
	return(0);
    }
    Cudd_Ref(com1);
    (void) printf("T-M L1 ");
    Cudd_PrintDebug(dd, com1, nvars, pr);
    sizeCom1 = Cudd_DagSize(com1);
    if (sizeCom1 > sizeF) {
	(void) printf("TEST-MINI: LI-compaction not safe (1).\n");
	return(0);
    }
    min1 = Cudd_bddMinimize(dd, f, c);
    if (min1 == NULL) {
	(void) printf("TEST-MINI: minimize failed (1).\n");
	return(0);
    }
    Cudd_Ref(min1);
    (void) printf("T-M M1 ");
    Cudd_PrintDebug(dd, min1, nvars, pr);
    sizeMin1 = Cudd_DagSize(min1);
    if (sizeMin1 > sizeF) {
	(void) printf("TEST-MINI: minimize not safe (1).\n");
	return(0);
    }
    rs1 = Cudd_bddRestrict(dd, f, c);
    if (rs1 == NULL) {
	(void) printf("TEST-MINI: restrict failed (1).\n");
	return(0);
    }
    Cudd_Ref(rs1);
    (void) printf("T-M R1 ");
    Cudd_PrintDebug(dd, rs1, nvars, pr);
    sizeRs1 = Cudd_DagSize(rs1);
    cs1 = Cudd_bddConstrain(dd, f, c);
    if (cs1 == NULL) {
	(void) printf("TEST-MINI: constrain failed (1).\n");
	return(0);
    }
    Cudd_Ref(cs1);
    (void) printf("T-M C1 ");
    Cudd_PrintDebug(dd, cs1, nvars, pr);
    sizeCs1 = Cudd_DagSize(cs1);
    l1 = Cudd_bddAnd(dd, f, c);
    if (l1 == NULL) {
	(void) printf("TEST-MINI: lower bound failed (1).\n");
	return(0);
    }
    Cudd_Ref(l1);
    u1 = Cudd_bddOr(dd, f, Cudd_Not(c));
    if (u1 == NULL) {
	(void) printf("TEST-MINI: upper bound failed (1).\n");
	return(0);
    }
    Cudd_Ref(u1);
    (void) printf("TEST-MINI: (lb,ub) : (%d,%d) nodes\n",
		  Cudd_DagSize(l1), Cudd_DagSize(u1));
    sq1 = Cudd_bddSqueeze(dd, l1, u1);
    if (sq1 == NULL) {
	(void) printf("TEST-MINI: squeezing failed (1).\n");
	return(0);
    }
    Cudd_Ref(sq1);
    sizeSq1 = Cudd_DagSize(sq1);
    if (sizeSq1 > sizeF) {
	Cudd_RecursiveDeref(dd,sq1);
	sq1 = f;
	Cudd_Ref(sq1);
	sizeSq1 = sizeF;
    }
    (void) printf("T-M S1 ");
    Cudd_PrintDebug(dd, sq1, nvars, pr);
    na1 = Cudd_bddNPAnd(dd, f, c);
    if (na1 == NULL) {
	(void) printf("TEST-MINI: NPand failed (1).\n");
	return(0);
    }
    Cudd_Ref(na1);
    (void) printf("T-M N1 ");
    Cudd_PrintDebug(dd, na1, nvars, pr);
    sizeNa1 = Cudd_DagSize(na1);
    a1 = Cudd_bddAnd(dd, f, c);
    if (a1 == NULL) {
	(void) printf("TEST-MINI: and failed (1).\n");
	return(0);
    }
    Cudd_Ref(a1);
    (void) printf("T-M A1 ");
    Cudd_PrintDebug(dd, a1, nvars, pr);
    sizeA1 = Cudd_DagSize(a1);
    (void) printf("TEST-MINI: f %d comp %d mini %d rest %d cons %d sque %d na %d and %d\n",
		  sizeF, sizeCom1, sizeMin1, sizeRs1, sizeCs1, sizeSq1, sizeNa1, sizeA1);
    if (option->bdddump) {
	onames[0] = name;		outputs[0] = f;
	onames[1] = cname;		outputs[1] = c;
	onames[2] = (char *) "cons";	outputs[2] = cs1;
	onames[3] = (char *) "rest";	outputs[3] = rs1;
	onames[4] = (char *) "comp";	outputs[4] = com1;
	onames[5] = (char *) "mini";	outputs[5] = min1;
	onames[6] = (char *) "sqee";	outputs[6] = sq1;
	onames[7] = (char *) "lb";	outputs[7] = l1;
	onames[8] = (char *) "ub";	outputs[8] = u1;
	onames[9] = (char *) "na";	outputs[9] = na1;
	onames[10] = (char *) "and";	outputs[10] = a1;
	if (!Bnet_bddArrayDump(dd, net1, option->dumpfile, outputs, onames,
			       11, option->dumpFmt))
	    return(0);
    }
    Cudd_RecursiveDeref(dd,l1);
    Cudd_RecursiveDeref(dd,u1);

    /* Compute negative generalized cofactor. */
    (void) printf("TEST-MINI:: %s\n", name);
    (void) printf("T-M    ");
    Cudd_PrintDebug(dd, f, nvars, pr);

    com0 = Cudd_bddLICompaction(dd, f, Cudd_Not(c));
    if (com0 == NULL) {
	(void) printf("TEST-MINI: LI-compaction failed (2).\n");
	return(0);
    }
    Cudd_Ref(com0);
    (void) printf("T-M L0 ");
    Cudd_PrintDebug(dd, com0, nvars, pr);
    sizeCom0 = Cudd_DagSize(com0);
    if (sizeCom0 > sizeF) {
	(void) printf("TEST-MINI: LI-compaction not safe (2).\n");
	return(0);
    }
    min0 = Cudd_bddMinimize(dd, f, Cudd_Not(c));
    if (min0 == NULL) {
	(void) printf("TEST-MINI: minimize failed (2).\n");
	return(0);
    }
    Cudd_Ref(min0);
    (void) printf("T-M M0 ");
    Cudd_PrintDebug(dd, min0, nvars, pr);
    sizeMin0 = Cudd_DagSize(min0);
    if (sizeMin0 > sizeF) {
	(void) printf("TEST-MINI: minimize not safe (2).\n");
	return(0);
    }
    rs0 = Cudd_bddRestrict(dd, f, Cudd_Not(c));
    if (rs0 == NULL) {
	(void) printf("TEST-MINI: restrict failed (2).\n");
	return(0);
    }
    Cudd_Ref(rs0);
    (void) printf("T-M R0 ");
    Cudd_PrintDebug(dd, rs0, nvars, pr);
    sizeRs0 = Cudd_DagSize(rs0);
    cs0 = Cudd_bddConstrain(dd, f, Cudd_Not(c));
    if (cs0 == NULL) {
	(void) printf("TEST-MINI: constrain failed (2).\n");
	return(0);
    }
    Cudd_Ref(cs0);
    (void) printf("T-M C0 ");
    Cudd_PrintDebug(dd, cs0, nvars, pr);
    sizeCs0 = Cudd_DagSize(cs0);

    l0 = Cudd_bddAnd(dd, f, Cudd_Not(c));
    if (l0 == NULL) {
	(void) printf("TEST-MINI: lower bound failed (2).\n");
	return(0);
    }
    Cudd_Ref(l0);
    u0 = Cudd_bddOr(dd, f, c);
    if (u0 == NULL) {
	(void) printf("TEST-MINI: upper bound failed (2).\n");
	return(0);
    }
    Cudd_Ref(u0);
    (void) printf("TEST-MINI: (lb,ub) : (%d,%d) nodes\n",
		  Cudd_DagSize(l0), Cudd_DagSize(u0));
    sq0 = Cudd_bddSqueeze(dd, l0, u0);
    if (sq0 == NULL) {
	(void) printf("TEST-MINI: squeezing failed (2).\n");
	return(0);
    }
    Cudd_Ref(sq0);
    Cudd_RecursiveDeref(dd,l0);
    Cudd_RecursiveDeref(dd,u0);
    sizeSq0 = Cudd_DagSize(sq0);
    if (sizeSq0 > sizeF) {
	Cudd_RecursiveDeref(dd,sq0);
	sq0 = f;
	Cudd_Ref(sq0);
	sizeSq0 = sizeF;
    }
    (void) printf("T-M S0 ");
    Cudd_PrintDebug(dd, sq0, nvars, pr);
    na0 = Cudd_bddNPAnd(dd, f, Cudd_Not(c));
    if (na0 == NULL) {
	(void) printf("TEST-MINI: NPand failed (2).\n");
	return(0);
    }
    Cudd_Ref(na0);
    (void) printf("T-M N0 ");
    Cudd_PrintDebug(dd, na0, nvars, pr);
    sizeNa0 = Cudd_DagSize(na0);
    a0 = Cudd_bddAnd(dd, f, Cudd_Not(c));
    if (a0 == NULL) {
	(void) printf("TEST-MINI: and failed (2).\n");
	return(0);
    }
    Cudd_Ref(a0);
    (void) printf("T-M A0 ");
    Cudd_PrintDebug(dd, a0, nvars, pr);
    sizeA0 = Cudd_DagSize(a0);
    (void) printf("TEST-MINI: f %d comp %d mini %d rest %d cons %d sque %d na %d, and %d\n",
		  sizeF, sizeCom0, sizeMin0, sizeRs0, sizeCs0, sizeSq0, sizeNa0, sizeA0);

    /* Check fundamental identity. */
    g = Cudd_bddIte(dd,c,com1,com0);
    if (g == NULL) {
	(void) printf("TEST-MINI: LI-compaction failed (3).\n");
	return(0);
    }
    Cudd_Ref(g);
    if (g != f) {
	(void) printf("TEST-MINI: LI-compaction failed (4).\n");
	return(0);
    }
    Cudd_RecursiveDeref(dd,com1);
    Cudd_RecursiveDeref(dd,com0);
    Cudd_RecursiveDeref(dd,g);
    g = Cudd_bddIte(dd,c,min1,min0);
    if (g == NULL) {
	(void) printf("TEST-MINI: minimize failed (3).\n");
	return(0);
    }
    Cudd_Ref(g);
    if (g != f) {
	(void) printf("TEST-MINI: minimize failed (4).\n");
	return(0);
    }
    Cudd_RecursiveDeref(dd,min1);
    Cudd_RecursiveDeref(dd,min0);
    Cudd_RecursiveDeref(dd,g);
    g = Cudd_bddIte(dd,c,sq1,sq0);
    if (g == NULL) {
	(void) printf("TEST-MINI: squeezing failed (3).\n");
	return(0);
    }
    Cudd_Ref(g);
    if (g != f) {
	(void) printf("TEST-MINI: squeezing failed (4).\n");
	return(0);
    }
    Cudd_RecursiveDeref(dd,sq1);
    Cudd_RecursiveDeref(dd,sq0);
    Cudd_RecursiveDeref(dd,g);
    g = Cudd_bddIte(dd,c,rs1,rs0);
    if (g == NULL) {
	(void) printf("TEST-MINI: restrict failed (3).\n");
	return(0);
    }
    Cudd_Ref(g);
    if (g != f) {
	(void) printf("TEST-MINI: restrict failed (4).\n");
	return(0);
    }
    Cudd_RecursiveDeref(dd,rs1);
    Cudd_RecursiveDeref(dd,rs0);
    Cudd_RecursiveDeref(dd,g);
    g = Cudd_bddIte(dd,c,cs1,cs0);
    if (g == NULL) {
	(void) printf("TEST-MINI: constrain failed (3).\n");
	return(0);
    }
    Cudd_Ref(g);
    if (g != f) {
	(void) printf("TEST-MINI: constrain failed (4).\n");
	return(0);
    }
    Cudd_RecursiveDeref(dd,cs1);
    Cudd_RecursiveDeref(dd,cs0);
    Cudd_RecursiveDeref(dd,g);
    g = Cudd_bddIte(dd,c,na1,na0);
    if (g == NULL) {
	(void) printf("TEST-MINI: NPand failed (3).\n");
	return(0);
    }
    Cudd_Ref(g);
    if (g != f) {
	(void) printf("TEST-MINI: NPand failed (4).\n");
	return(0);
    }
    Cudd_RecursiveDeref(dd,na1);
    Cudd_RecursiveDeref(dd,na0);
    Cudd_RecursiveDeref(dd,g);
    g = Cudd_bddIte(dd,c,a1,a0);
    if (g == NULL) {
	(void) printf("TEST-MINI: and failed (3).\n");
	return(0);
    }
    Cudd_Ref(g);
    if (g != f) {
	(void) printf("TEST-MINI: and failed (4).\n");
	return(0);
    }
    Cudd_RecursiveDeref(dd,a1);
    Cudd_RecursiveDeref(dd,a0);
    Cudd_RecursiveDeref(dd,g);

    return(1);

} /* end of ntrTestMinimizationAux */


/**
  @brief Processes one %BDD for Ntr_TestDensity.

  @return 1 if successful; 0 otherwise.

  @sideeffect None

  @see Ntr_TestDensity ntrCompress1

*/
static int
ntrTestDensityAux(
  DdManager * dd,
  BnetNetwork * net,
  DdNode * f,
  char * name,
  NtrOptions * option)
{
    DdNode *s, *b, *hb, *sp, *ua, *c1, *c2;
    int pr;
    int result;
    int nvars;
    int size, sizeS;
    double densityF, densityB, densityS, densityHB, densitySP, densityUA;
    double densityC1, densityC2;
    char *onames[8];
    DdNode *outputs[8];

    result = 1;
    pr = option->verb;
    nvars = Cudd_SupportSize(dd,f);
    if (nvars == CUDD_OUT_OF_MEM) return(0);
    densityF = Cudd_Density(dd,f,nvars);
    (void) printf("TEST-DENSITY:: %s (%d variables)\n", name, nvars);
    if (pr > 0) {
	(void) printf("T-D    (%g)", densityF);
	Cudd_PrintDebug(dd, f, nvars, pr);
	(void) printf("T-D APA ");
	if (!Cudd_ApaPrintMinterm(stdout, dd, f, nvars))
	    result = 0;
    }
    /* Test remapping underapproximation. */
    /* s = Cudd_SubsetRemap(dd,f); */
    s = Cudd_RemapUnderApprox(dd,f,nvars,0,option->quality);
    if (s == NULL) {
	(void) printf("TEST-DENSITY: computation failed\n");
	return(0);
    }
    Cudd_Ref(s);
    sizeS = Cudd_DagSize(s);
    densityS = Cudd_Density(dd,s,nvars);
    if (pr > 0) {
	(void) printf("T-D ID (%g)", densityS);
	Cudd_PrintDebug(dd, s, nvars, pr);
    }
    if (!Cudd_bddLeq(dd,s,f)) {
	(void) printf("TEST-DENSITY: result not a subset\n");
	result = 0;
    }
    if (densityF > densityS) {
	(void) printf("TEST-DENSITY: result less dense\n");
	/* result = 0; */
    }
    size = sizeS;
    /* Test biased underapproximation. */
    b = Cudd_BiasedUnderApprox(dd,f,Cudd_Not(s),nvars,0,
			       option->quality*1.1,option->quality*0.5);
    if (b == NULL) {
	(void) printf("TEST-DENSITY: computation failed\n");
	return(0);
    }
    Cudd_Ref(b);
    densityB = Cudd_Density(dd,b,nvars);
    if (pr > 0) {
	(void) printf("T-D BU (%g)", densityB);
	Cudd_PrintDebug(dd, b, nvars, pr);
    }
    if (!Cudd_bddLeq(dd,b,f)) {
	(void) printf("TEST-DENSITY: result not a subset\n");
	result = 0;
    }
    if (densityF > densityB) {
	(void) printf("TEST-DENSITY: result less dense\n");
	/* result = 0; */
    }
    /* Test heavy-branch subsetting. */
    hb = Cudd_SubsetHeavyBranch(dd, f, nvars, size);
    if (hb == NULL) {
	(void) printf("TEST-DENSITY: HB computation failed\n");
	Cudd_RecursiveDeref(dd,s);
	return(0);
    }
    Cudd_Ref(hb);
    densityHB = Cudd_Density(dd,hb,nvars);
    if (pr > 0) {
	(void) printf("T-D HB (%g)", densityHB);
	Cudd_PrintDebug(dd, hb, nvars, pr);
    }
    if (!Cudd_bddLeq(dd,hb,f)) {
	(void) printf("TEST-DENSITY: HB not a subset\n");
	result = 0;
    }
    /* Test short paths subsetting. */
    sp = Cudd_SubsetShortPaths(dd, f, nvars, size, 0);
    if (sp == NULL) {
	(void) printf("TEST-DENSITY: SP computation failed\n");
	Cudd_RecursiveDeref(dd,s);
	Cudd_RecursiveDeref(dd,hb);
	return(0);
    }
    Cudd_Ref(sp);
    densitySP = Cudd_Density(dd,sp,nvars);
    if (pr > 0) {
	(void) printf("T-D SP (%g)", densitySP);
	Cudd_PrintDebug(dd, sp, nvars, pr);
    }
    if (!Cudd_bddLeq(dd,sp,f)) {
	(void) printf("TEST-DENSITY: SP not a subset\n");
	result = 0;
    }
    /* Test underapproximation. */
    ua = Cudd_UnderApprox(dd,f,nvars,0,FALSE,option->quality);
    if (ua == NULL) {
	(void) printf("TEST-DENSITY: computation failed\n");
	Cudd_RecursiveDeref(dd,s);
	Cudd_RecursiveDeref(dd,hb);
	Cudd_RecursiveDeref(dd,sp);
	return(0);
    }
    Cudd_Ref(ua);
    densityUA = Cudd_Density(dd,ua,nvars);
    if (pr > 0) {
	(void) printf("T-D UA (%g)", densityUA);
	Cudd_PrintDebug(dd, ua, nvars, pr);
    }
    if (!Cudd_bddLeq(dd,ua,f)) {
	(void) printf("TEST-DENSITY: result not a subset\n");
	result = 0;
    }
    if (densityF > densityUA) {
	(void) printf("TEST-DENSITY: result less dense\n");
    }
    /* Test compress 2 method. */
    c1 = ntrCompress2(dd, f, nvars, size);
    if (c1 == NULL) {
	(void) printf("TEST-DENSITY: C1 computation failed\n");
	Cudd_RecursiveDeref(dd,s);
	Cudd_RecursiveDeref(dd,hb);
	Cudd_RecursiveDeref(dd,sp);
	Cudd_RecursiveDeref(dd,ua);
	return(0);
    }
    densityC1 = Cudd_Density(dd,c1,nvars);
    if (pr > 0) {
	(void) printf("T-D C1 (%g)", densityC1);
	Cudd_PrintDebug(dd, c1, nvars, pr);
    }
    if (!Cudd_bddLeq(dd,c1,f)) {
	(void) printf("TEST-DENSITY: C1 not a subset\n");
	result = 0;
    }
    /* Test compress subsetting. */
    c2 = Cudd_SubsetCompress(dd, f, nvars, size);
    if (c2 == NULL) {
	(void) printf("TEST-DENSITY: C2 computation failed\n");
	Cudd_RecursiveDeref(dd,s);
	Cudd_RecursiveDeref(dd,hb);
	Cudd_RecursiveDeref(dd,sp);
	Cudd_RecursiveDeref(dd,ua);
	Cudd_RecursiveDeref(dd,c1);
	return(0);
    }
    Cudd_Ref(c2);
    densityC2 = Cudd_Density(dd,c2,nvars);
    if (pr > 0) {
	(void) printf("T-D C2 (%g)", densityC2);
	Cudd_PrintDebug(dd, c2, nvars, pr);
    }
    if (!Cudd_bddLeq(dd,c2,f)) {
	(void) printf("TEST-DENSITY: C2 not a subset\n");
	result = 0;
    }
    /* Dump results if so requested. */
    if (option->bdddump) {
	onames[0] = name;		outputs[0] = f;
	onames[1] = (char *) "id";	outputs[1] = s;
	onames[2] = (char *) "bu";	outputs[2] = b;
	onames[3] = (char *) "hb";	outputs[3] = hb;
	onames[4] = (char *) "sp";	outputs[4] = sp;
	onames[5] = (char *) "ua";	outputs[5] = ua;
	onames[6] = (char *) "c1";	outputs[6] = c1;
	onames[7] = (char *) "c2";	outputs[7] = c2;
	result &= Bnet_bddArrayDump(dd, net, option->dumpfile, outputs,
				     onames, 8, option->dumpFmt);
    }

    Cudd_RecursiveDeref(dd,s);
    Cudd_RecursiveDeref(dd,b);
    Cudd_RecursiveDeref(dd,hb);
    Cudd_RecursiveDeref(dd,sp);
    Cudd_RecursiveDeref(dd,ua);
    Cudd_RecursiveDeref(dd,c1);
    Cudd_RecursiveDeref(dd,c2);

    return(result);

} /* end of ntrTestDensityAux */


/**
  @brief Processes one %BDD for Ntr_TestDecomp.

  @return 1 if successful; 0 otherwise.

  @sideeffect None

  @see Ntr_TestDecomp

*/
static int
ntrTestDecompAux(
  DdManager * dd,
  BnetNetwork * net,
  DdNode * f,
  char * name,
  NtrOptions * option)
{
    DdNode *one, *g, *h, *product;
    DdNode **A, **I, **G, **V;
    int pr;
    int i, result;
    int nA, nI, nG, nV;
    int nvars;
    int sizeSa;
    int sizeSi, sizeSg, sizeSv;
    char *onames[9];
    DdNode *outputs[9];

    result = 1;
    pr = option->verb;
    nvars = Cudd_SupportSize(dd,f);
    if (nvars == CUDD_OUT_OF_MEM) return(0);
    (void) printf("TEST-DECOMP:: %s (%d variables)\n", name, nvars);
    if (pr > 0) {
	(void) printf("T-d    ");
	Cudd_PrintDebug(dd, f, nvars, pr);
    }
    one = Cudd_ReadOne(dd);

    /* Test Cudd_bddApproxConjDecomp */
    nA = Cudd_bddApproxConjDecomp(dd,f,&A);
    if (nA == 0) {
	(void) printf("TEST-DECOMP: computation failed\n");
	return(0);
    }
    g = A[0];
    h = (nA == 2) ? A[1] : one;
    sizeSa = Cudd_SharingSize(A,nA);
    if (pr > 0) {
	(void) printf("T-d SS : %d nodes\n", sizeSa);
	(void) printf("T-d GS ");
	Cudd_PrintDebug(dd, g, nvars, pr);
	(void) printf("T-d HS ");
	Cudd_PrintDebug(dd, h, nvars, pr);
    }
    product = Cudd_bddAnd(dd,g,h);
    if (product == NULL) {
	(void) printf("TEST-DECOMP: computation failed\n");
	return(0);
    }
    Cudd_Ref(product);
    if (product != f) {
	(void) printf("TEST-DECOMP: result not a decomposition\n");
	result = 0;
    }
    Cudd_RecursiveDeref(dd,product);

    /* Test Cudd_bddIterConjDecomp */
    nI = Cudd_bddIterConjDecomp(dd,f,&I);
    if (nI == 0) {
	(void) printf("TEST-DECOMP: computation failed\n");
	return(0);
    }
    g = I[0];
    h = (nI == 2) ? I[1] : one;
    sizeSi = Cudd_SharingSize(I,nI);
    if (pr > 0) {
	(void) printf("T-d SI : %d nodes\n", sizeSi);
	(void) printf("T-d GI ");
	Cudd_PrintDebug(dd, g, nvars, pr);
	(void) printf("T-d HI ");
	Cudd_PrintDebug(dd, h, nvars, pr);
    }
    product = Cudd_bddAnd(dd,g,h);
    if (product == NULL) {
	(void) printf("TEST-DECOMP: computation failed\n");
	return(0);
    }
    Cudd_Ref(product);
    if (product != f) {
	(void) printf("TEST-DECOMP: result not a decomposition\n");
	result = 0;
    }
    Cudd_RecursiveDeref(dd,product);

    /* Test Cudd_bddGenConjDecomp */
    nG = Cudd_bddGenConjDecomp(dd,f,&G);
    if (nG == 0) {
	(void) printf("TEST-DECOMP: computation failed\n");
	return(0);
    }
    g = G[0];
    h = (nG == 2) ? G[1] : one;
    sizeSg = Cudd_SharingSize(G,nG);
    if (pr > 0) {
	(void) printf("T-d SD : %d nodes\n", sizeSg);
	(void) printf("T-d GD ");
	Cudd_PrintDebug(dd, g, nvars, pr);
	(void) printf("T-d HD ");
	Cudd_PrintDebug(dd, h, nvars, pr);
    }
    product = Cudd_bddAnd(dd,g,h);
    if (product == NULL) {
	(void) printf("TEST-DECOMP: computation failed\n");
	return(0);
    }
    Cudd_Ref(product);
    if (product != f) {
	(void) printf("TEST-DECOMP: result not a decomposition\n");
	result = 0;
    }
    Cudd_RecursiveDeref(dd,product);

    /* Test Cudd_bddVarConjDecomp */
    nV = Cudd_bddVarConjDecomp(dd,f,&V);
    if (nV == 0) {
	(void) printf("TEST-DECOMP: computation failed\n");
	return(0);
    }
    g = V[0];
    h = (nV == 2) ? V[1] : one;
    sizeSv = Cudd_SharingSize(V,nV);
    if (pr > 0) {
	(void) printf("T-d SQ : %d nodes\n", sizeSv);
	(void) printf("T-d GQ ");
	Cudd_PrintDebug(dd, g, nvars, pr);
	(void) printf("T-d HQ ");
	Cudd_PrintDebug(dd, h, nvars, pr);
    }
    product = Cudd_bddAnd(dd,g,h);
    if (product == NULL) {
	(void) printf("TEST-DECOMP: computation failed\n");
	return(0);
    }
    Cudd_Ref(product);
    if (product != f) {
	(void) printf("TEST-DECOMP: result not a decomposition\n");
	result = 0;
    }
    Cudd_RecursiveDeref(dd,product);

    /* Dump to file if requested. */
    if (option->bdddump) {
	onames[0] = name;		outputs[0] = f;
	onames[1] = (char *) "ga";	outputs[1] = A[0];
	onames[2] = (char *) "ha";	outputs[2] = (nA == 2) ? A[1] : one;
	onames[3] = (char *) "gi";	outputs[3] = I[0];
	onames[4] = (char *) "hi";	outputs[4] = (nI == 2) ? I[1] : one;
	onames[5] = (char *) "gg";	outputs[5] = G[0];
	onames[6] = (char *) "hg";	outputs[6] = (nG == 2) ? G[1] : one;
	onames[7] = (char *) "gv";	outputs[7] = V[0];
	onames[8] = (char *) "hv";	outputs[8] = (nV == 2) ? V[1] : one;
	result &= Bnet_bddArrayDump(dd, net, option->dumpfile, outputs,
				     onames, 9, option->dumpFmt);
    }

    /* Clean up. */
    for (i = 0; i < nA; i++) {
	Cudd_RecursiveDeref(dd,A[i]);
    }
    for (i = 0; i < nI; i++) {
	Cudd_RecursiveDeref(dd,I[i]);
    }
    for (i = 0; i < nG; i++) {
	Cudd_RecursiveDeref(dd,G[i]);
    }
    for (i = 0; i < nV; i++) {
	Cudd_RecursiveDeref(dd,V[i]);
    }
    FREE(A);
    FREE(I);
    FREE(G);
    FREE(V);

    return(result);

} /* end of ntrTestDecompAux */


/**
  @brief Processes one %BDD for Ntr_TestCofactorEstimate.

  @return 1 if successful; 0 otherwise.

  @sideeffect None

*/
static int
ntrTestCofEstAux(
  DdManager * dd,
  BnetNetwork * net,
  DdNode * f,
  char * name,
  NtrOptions * option)
{
    DdNode *support, *scan, *cof;
    int pr;
    int nvars;
    int exactSize, estimate, estimateS;
    int totalExactSize = 0;
    int totalEstimate = 0;
    int totalEstimateS = 0;
    int largestError = -1;
    int largestErrorS = -1;
    DdNode *errorVar = NULL;

    pr = option->verb;
    support = Cudd_Support(dd,f);
    if (support == NULL) return(0);
    Cudd_Ref(support);
    nvars = Cudd_DagSize(support) - 1;
    scan = support;
    while (!Cudd_IsConstant(scan)) {
	DdNode *var = Cudd_bddIthVar(dd,scan->index);
	cof = Cudd_Cofactor(dd,f,var);
	if (cof == NULL) return(0);
	Cudd_Ref(cof);
	exactSize = Cudd_DagSize(cof);
	totalExactSize += exactSize;
	estimate = Cudd_EstimateCofactor(dd,f,scan->index,1);
	totalEstimate += estimate;
	if (estimate < exactSize)
	    (void) printf("Optimistic estimate!\n");
	if (estimate - exactSize > largestError) {
	    largestError = estimate - exactSize;
	    errorVar = var;
	}
	estimateS = Cudd_EstimateCofactorSimple(f,scan->index);
	totalEstimateS += estimateS;
	if (estimateS < exactSize)
	    (void) printf("Optimistic estimateS!\n");
	if (estimateS - exactSize > largestErrorS)
	    largestErrorS = estimateS - exactSize;
	Cudd_RecursiveDeref(dd,cof);
	scan = cuddT(scan);
    }
    Cudd_RecursiveDeref(dd,support);
    (void) printf("TEST-COF:: %s (%d vars)", name, nvars);
    Cudd_PrintDebug(dd, f, nvars, pr);
    (void) printf("T-c   : %d\n", totalExactSize);
    (void) printf("T-c E : %d %d\n", totalEstimate, largestError);
    (void) printf("T-c S : %d %d\n", totalEstimateS, largestErrorS);

    /* Dump to file if requested. */
    if (option->bdddump) {
	char *onames[3];
	DdNode *outputs[3];
	int result;
	cof = Cudd_Cofactor(dd,f,errorVar);
	if (cof == NULL) return(0);
	Cudd_Ref(cof);
	onames[0] = name;		outputs[0] = f;
	onames[1] = (char *) "var";	outputs[1] = errorVar;
	onames[2] = (char *) "cof";	outputs[2] = cof;
	result = Bnet_bddArrayDump(dd, net, option->dumpfile, outputs,
				     onames, 3, option->dumpFmt);
	Cudd_RecursiveDeref(dd,cof);
	if (result == 0) return(0);
    }

    return(1);

} /* end of ntrTestCofEstAux */


/**
  @brief Processes one %BDD for Ntr_TestClipping.

  @details It checks whether clipping was correct.

  @return 1 if successful; 0 otherwise.

  @sideeffect None

  @see Ntr_TestClipping

*/
static int
ntrTestClippingAux(
  DdManager * dd,
  BnetNetwork * net1,
  DdNode * f,
  char * name,
  DdNode * g,
  char * gname,
  NtrOptions * option)
{
    DdNode *prod, *sub, *sup;
    DdNode *subF, *subG, *psub;
    DdNode *supF, *supG, *psup;
    int pr, nvars, depth;
    int sizeProd, sizeSub, sizeSup;
    static char *onames[7];
    DdNode *outputs[7];
    DdNode *operands[2];
    int retval = 1;
    int threshold = (option->threshold < 0) ? 0 : option->threshold;

    pr = option->verb;
    operands[0] = f; operands[1] = g;
    nvars = Cudd_VectorSupportSize(dd,operands,2);
    if (nvars == CUDD_OUT_OF_MEM) return(0);
    depth = (int) ((double) nvars * option->clip);
    (void) printf("TEST-CLIP:: %s depth = %d\n", name, depth);
    (void) printf("T-C    ");
    Cudd_PrintDebug(dd, f, nvars, pr);

    /* Compute product. */
    prod = Cudd_bddAnd(dd, f, g);
    if (prod == NULL) {
	(void) printf("TEST-CLIP: product failed.\n");
	return(0);
    }
    Cudd_Ref(prod);
    (void) printf("T-C P= ");
    Cudd_PrintDebug(dd, prod, nvars, pr);
    sizeProd = Cudd_DagSize(prod);

    /* Compute subset of product. */
    sub = Cudd_bddClippingAnd(dd, f, g, depth, 0);
    if (sub == NULL) {
	(void) printf("TEST-CLIP: subsetting product failed.\n");
	return(0);
    }
    Cudd_Ref(sub);
    (void) printf("T-C P- ");
    Cudd_PrintDebug(dd, sub, nvars, pr);
    sizeSub = Cudd_DagSize(sub);
    if (sizeSub > sizeProd) {
	(void) printf("TEST-CLIP: subsetting product not safe.\n");
    }

    /* Compute product of subsets. */
    subF = Cudd_RemapUnderApprox(dd,f,nvars,threshold,option->quality);
    if (subF == NULL) {
	(void) printf("TEST-CLIP: subsetting of f failed.\n");
	return(0);
    }
    Cudd_Ref(subF);
    subG = Cudd_RemapUnderApprox(dd,g,nvars,threshold,option->quality);
    if (subF == NULL) {
	(void) printf("TEST-CLIP: subsetting of g failed.\n");
	return(0);
    }
    Cudd_Ref(subG);
    psub = Cudd_bddAnd(dd,subF,subG);
    if (psub == NULL) {
	(void) printf("TEST-CLIP: product of subsets failed.\n");
	return(0);
    }
    Cudd_Ref(psub);
    Cudd_RecursiveDeref(dd,subF);
    Cudd_RecursiveDeref(dd,subG);
    (void) printf("T-C P< ");
    Cudd_PrintDebug(dd, psub, nvars, pr);

    /* Compute superset of product. */
    sup = Cudd_bddClippingAnd(dd, f, g, depth, 1);
    if (sup == NULL) {
	(void) printf("TEST-CLIP: supersetting product failed.\n");
	return(0);
    }
    Cudd_Ref(sup);
    (void) printf("T-C P+ ");
    Cudd_PrintDebug(dd, sup, nvars, pr);
    sizeSup = Cudd_DagSize(sup);
    if (sizeSup > sizeProd) {
	(void) printf("TEST-CLIP: supersetting product not safe.\n");
    }

    /* Compute product of supersets. */
    supF = Cudd_RemapOverApprox(dd,f,nvars,threshold,option->quality);
    if (supF == NULL) {
	(void) printf("TEST-CLIP: supersetting of f failed.\n");
	return(0);
    }
    Cudd_Ref(supF);
    supG = Cudd_RemapOverApprox(dd,g,nvars,threshold,option->quality);
    if (supF == NULL) {
	(void) printf("TEST-CLIP: supersetting of g failed.\n");
	return(0);
    }
    Cudd_Ref(supG);
    psup = Cudd_bddAnd(dd,supF,supG);
    if (psup == NULL) {
	(void) printf("TEST-CLIP: product of supersets failed.\n");
	return(0);
    }
    Cudd_Ref(psup);
    Cudd_RecursiveDeref(dd,supF);
    Cudd_RecursiveDeref(dd,supG);
    (void) printf("T-C P> ");
    Cudd_PrintDebug(dd, psup, nvars, pr);

    if (option->bdddump) {
	onames[0] = name;		outputs[0] = f;
	onames[1] = gname;		outputs[1] = g;
	onames[2] = (char *) "prod";	outputs[2] = prod;
	onames[3] = (char *) "sub";	outputs[3] = sub;
	onames[4] = (char *) "sup";	outputs[4] = sup;
	onames[5] = (char *) "psub";	outputs[5] = psub;
	onames[6] = (char *) "psup";	outputs[6] = psup;
	retval &= Bnet_bddArrayDump(dd, net1, option->dumpfile, outputs,
				     onames, 7, option->dumpFmt);
    }

    /* Check correctness. */
    if (!Cudd_bddLeq(dd,sub,prod)) {
	(void) printf("TEST-CLIP: subsetting product not a subset.\n");
	return(0);
    }
    if (!Cudd_bddLeq(dd,prod,sup)) {
	(void) printf("TEST-CLIP: supersetting product not a superset.\n");
	return(0);
    }
    if (!Cudd_bddLeq(dd,psub,prod)) {
	(void) printf("TEST-CLIP: product of subsets not a subset.\n");
	return(0);
    }
    if (!Cudd_bddLeq(dd,prod,psup)) {
	(void) printf("TEST-CLIP: product of supersets not a superset.\n");
	return(0);
    }

    Cudd_RecursiveDeref(dd,prod);
    Cudd_RecursiveDeref(dd,sub);
    Cudd_RecursiveDeref(dd,sup);
    Cudd_RecursiveDeref(dd,psub);
    Cudd_RecursiveDeref(dd,psup);

    return(retval);

} /* end of ntrTestClippingAux */



/**
  @brief Processes one triplet of BDDs for Ntr_TestEquivAndContain.

  @return 1 if successful; 0 otherwise.

  @sideeffect None

  @see Ntr_TestEquivAndContain

*/
static int
ntrTestEquivAndContainAux(
  DdManager *dd,
  BnetNetwork *net1,
  DdNode *f,
  char *fname,
  DdNode *g,
  char *gname,
  DdNode *d,
  char *dname,
  NtrOptions *option)
{
    DdNode *xor_, *diff, *ndiff;
    int pr, nvars;
    int equiv, implies;
    static char *onames[6];
    DdNode *outputs[6];
    DdNode *fgd[3];

    pr = option->verb;
    fgd[0] = f; fgd[1] = g; fgd[2] = d;
    nvars = Cudd_VectorSupportSize(dd,fgd,3);
    if (nvars == CUDD_OUT_OF_MEM) return(0);
    (void) printf("TEST-DC:: %s [=<]= %s unless %s\n", fname, gname, dname);
    (void) printf("T-F    ");
    Cudd_PrintDebug(dd, f, nvars, pr);
    (void) printf("T-G    ");
    Cudd_PrintDebug(dd, g, nvars, pr);
    (void) printf("T-D    ");
    Cudd_PrintDebug(dd, d, nvars, pr);

    /* Check equivalence unless don't cares. */
    xor_ = Cudd_bddXor(dd, f, g);
    if (xor_ == NULL) {
	(void) printf("TEST-DC: XOR computation failed (1).\n");
	return(0);
    }
    Cudd_Ref(xor_);
    equiv = Cudd_EquivDC(dd, f, g, d);
    if (equiv != Cudd_bddLeq(dd,xor_,d)) {
	(void) printf("TEST-DC: EquivDC computation incorrect (1).\n");
	(void) printf("  EquivDC states that %s and %s are %s\n",
		      fname, gname, equiv ? "equivalent" : "not equivalent");
	(void) printf("T-X    ");
	Cudd_PrintDebug(dd, xor_, nvars, pr);
	return(0);
    }
    equiv = Cudd_EquivDC(dd, f, g, Cudd_Not(d));
    if (equiv != Cudd_bddLeq(dd,xor_,Cudd_Not(d))) {
	(void) printf("TEST-DC: EquivDC computation incorrect (2).\n");
	(void) printf("  EquivDC states that %s and %s are %s\n",
		      fname, gname, equiv ? "equivalent" : "not equivalent");
	(void) printf("T-X    ");
	Cudd_PrintDebug(dd, xor_, nvars, pr);
	return(0);
    }
    equiv = Cudd_EquivDC(dd, f, Cudd_Not(g), d);
    if (equiv != Cudd_bddLeq(dd,Cudd_Not(xor_),d)) {
	(void) printf("TEST-DC: EquivDC computation incorrect (3).\n");
	(void) printf("  EquivDC states that %s and not %s are %s\n",
		      fname, gname, equiv ? "equivalent" : "not equivalent");
	(void) printf("T-X    ");
	Cudd_PrintDebug(dd, Cudd_Not(xor_), nvars, pr);
	return(0);
    }
    equiv = Cudd_EquivDC(dd, f, Cudd_Not(g), Cudd_Not(d));
    if (equiv != Cudd_bddLeq(dd,d,xor_)) {
	(void) printf("TEST-DC: EquivDC computation incorrect (4).\n");
	(void) printf("  EquivDC states that %s and not %s are %s\n",
		      fname, gname, equiv ? "equivalent" : "not equivalent");
	(void) printf("T-X    ");
	Cudd_PrintDebug(dd, Cudd_Not(xor_), nvars, pr);
	return(0);
    }

    /* Check containment unless don't cares. */
    diff = Cudd_bddAnd(dd, f, Cudd_Not(g));
    if (diff == NULL) {
	(void) printf("TEST-DC: AND/NOT computation failed (1).\n");
	return(0);
    }
    Cudd_Ref(diff);
    implies = Cudd_bddLeqUnless(dd, f, g, d);
    if (implies != Cudd_bddLeq(dd,diff,d)) {
	(void) printf("TEST-DC: LeqUnless computation incorrect (1).\n");
	(void) printf("  LeqUnless states that %s %s %s\n",
		      fname, implies ? "implies" : "does not imply", gname);
	(void) printf("T-I    ");
	Cudd_PrintDebug(dd, diff, nvars, pr);
	return(0);
    }
    implies = Cudd_bddLeqUnless(dd, f, g, Cudd_Not(d));
    if (implies != Cudd_bddLeq(dd,diff,Cudd_Not(d))) {
	(void) printf("TEST-DC: LeqUnless computation incorrect (2).\n");
	(void) printf("  LeqUnless states that %s %s %s\n",
		      fname, implies ? "implies" : "does not imply", gname);
	(void) printf("T-I    ");
	Cudd_PrintDebug(dd, diff, nvars, pr);
	return(0);
    }
    ndiff = Cudd_bddAnd(dd, f, g);
    if (ndiff == NULL) {
	(void) printf("TEST-DC: AND computation failed (3).\n");
	return(0);
    }
    Cudd_Ref(ndiff);
    implies = Cudd_bddLeqUnless(dd, f, Cudd_Not(g), d);
    if (implies != Cudd_bddLeq(dd,ndiff,d)) {
	(void) printf("TEST-DC: LeqUnless computation incorrect (3).\n");
	(void) printf("  LeqUnless states that %s %s not(%s)\n",
		      fname, implies ? "implies" : "does not imply", gname);
	(void) printf("T-I    ");
	Cudd_PrintDebug(dd, ndiff, nvars, pr);
	return(0);
    }
    implies = Cudd_bddLeqUnless(dd, f, Cudd_Not(g), Cudd_Not(d));
    if (implies != Cudd_bddLeq(dd,ndiff,Cudd_Not(d))) {
	(void) printf("TEST-DC: LeqUnless computation incorrect (3).\n");
	(void) printf("  LeqUnless states that %s %s not(%s)\n",
		      fname, implies ? "implies" : "does not imply", gname);
	(void) printf("T-I    ");
	Cudd_PrintDebug(dd, ndiff, nvars, pr);
	return(0);
    }
    if (option->bdddump) {
	onames[0] = fname;		outputs[0] = f;
	onames[1] = gname;		outputs[1] = g;
	onames[2] = dname;		outputs[2] = d;
	onames[3] = (char *) "xor";	outputs[3] = xor_;
	onames[4] = (char *) "diff";	outputs[4] = diff;
	onames[5] = (char *) "ndiff";	outputs[5] = ndiff;
	if (!Bnet_bddArrayDump(dd, net1, option->dumpfile, outputs, onames,
			       6, option->dumpFmt))
	    return(0);
    }
    Cudd_RecursiveDeref(dd,xor_);
    Cudd_RecursiveDeref(dd,diff);
    Cudd_RecursiveDeref(dd,ndiff);

    return(1);

} /* end of ntrTestEquivAndContainAux */


/**
  @brief Processes one pair of BDDs for Ntr_TestClosestCube.

  @return 1 if successful; 0 otherwise.

  @sideeffect None

  @see Ntr_TestClosestCube

*/
static int
ntrTestClosestCubeAux(
  DdManager *dd,
  BnetNetwork *net,
  DdNode *f,
  char *fname,
  DdNode *g,
  char *gname,
  DdNode **vars,
  NtrOptions *option)
{
    DdNode *cube, *cubeN;
    int distance, pr, nvars;
    DdNode *fg[2];
    static char *onames[4];
    DdNode *outputs[4];

    pr = option->verb;
    fg[0] = f; fg[1] = g;
    nvars = Cudd_VectorSupportSize(dd,fg,2);
    if (nvars == CUDD_OUT_OF_MEM) return(0);
    (void) printf("TEST-CC:: H(%s, %s)\n", fname, gname);
    (void) printf("T-F    ");
    Cudd_PrintDebug(dd, f, nvars, pr);
    (void) printf("T-G    ");
    Cudd_PrintDebug(dd, g, nvars, pr);

    cube = Cudd_bddClosestCube(dd, f, g, &distance);
    if (cube == NULL) {
	(void) printf("TEST-CC: computation failed (1).\n");
	return(0);
    }
    Cudd_Ref(cube);
    (void) printf("T-C (%d) ", distance);
    Cudd_PrintDebug(dd, cube, nvars, pr);
    if (distance == 0) {
	if (!Cudd_bddLeq(dd,cube,g)) {
	    (void) printf("TEST-CC: distance-0 cube not in g (2).\n");
	    return(0);
	}
    }

    (void) printf("T-GN   ");
    Cudd_PrintDebug(dd, Cudd_Not(g), nvars, pr);
    cubeN = Cudd_bddClosestCube(dd, f, Cudd_Not(g), &distance);
    if (cubeN == NULL) {
	(void) printf("TEST-CC: computation failed (3).\n");
	return(0);
    }
    Cudd_Ref(cubeN);
    (void) printf("T-N (%d) ", distance);
    Cudd_PrintDebug(dd, cubeN, nvars, pr);
    if (distance == 0) {
	if (!Cudd_bddLeq(dd,cubeN,Cudd_Not(g))) {
	    (void) printf("TEST-CC: distance-0 cube not in not(g) (4).\n");
	    return(0);
	}
    } else {
	int d, *minterm;
	int numvars = Cudd_ReadSize(dd);
	DdNode *scan, *zero;
	DdNode *minBdd = Cudd_bddPickOneMinterm(dd,cubeN,vars,numvars);
	if (minBdd == NULL) {
	    (void) printf("TEST-CC: minterm selection failed (5).\n");
	    return(0);
	}
	Cudd_Ref(minBdd);
	minterm = ALLOC(int,numvars);
	if (minterm == NULL) {
	    (void) printf("TEST-CC: allocation failed (6).\n");
	    Cudd_RecursiveDeref(dd,minBdd);
	    return(0);
	}
	scan = minBdd;
	zero = Cudd_Not(DD_ONE(dd));
	while (!Cudd_IsConstant(scan)) {
	    DdNode *R = Cudd_Regular(scan);
	    DdNode *T = Cudd_T(R);
	    DdNode *E = Cudd_E(R);
	    if (R != scan) {
		T = Cudd_Not(T);
		E = Cudd_Not(E);
	    }
	    if (T == zero) {
		minterm[Cudd_NodeReadIndex(R)] = 0;
		scan = E;
	    } else {
		minterm[Cudd_NodeReadIndex(R)] = 1;
		scan = T;
	    }
	}
	Cudd_RecursiveDeref(dd,minBdd);
	d = Cudd_MinHammingDist(dd,Cudd_Not(g),minterm,numvars);
	FREE(minterm);
	if (d != distance) {
	    (void) printf("TEST-CC: distance disagreement (7).\n");
	    return(0);
	}
    }

    if (option->bdddump) {
	onames[0] = fname;		outputs[0] = f;
	onames[1] = gname;		outputs[1] = g;
	onames[2] = (char *) "cube";	outputs[2] = cube;
	onames[3] = (char *) "cubeN";	outputs[3] = cubeN;
	if (!Bnet_bddArrayDump(dd, net, option->dumpfile, outputs, onames,
			       4, option->dumpFmt))
	    return(0);
    }
    Cudd_RecursiveDeref(dd,cube);
    Cudd_RecursiveDeref(dd,cubeN);

    return(1);

} /* end of ntrTestClosestCubeAux */


/**
  @brief Processes one BDDs for Ntr_TestCharToVect.

  @return 1 if successful; 0 otherwise.

  @sideeffect None

  @see Ntr_TestCharToVect

*/
static int
ntrTestCharToVect(
  DdManager * dd,
  DdNode * f,
  NtrOptions *option)
{
    DdNode **vector;
    int sharingSize;
    DdNode *verify;
    int pr = option->verb;
    int i;

    (void) fprintf(stdout,"f");
    Cudd_PrintDebug(dd, f, Cudd_ReadSize(dd), 1);
    if (pr > 1) {
	Cudd_bddPrintCover(dd, f, f);
    }
    vector = Cudd_bddCharToVect(dd,f);
    if (vector == NULL) return(0);
    sharingSize = Cudd_SharingSize(vector, Cudd_ReadSize(dd));
    (void) fprintf(stdout, "Vector Size: %d components %d nodes\n",
		   Cudd_ReadSize(dd), sharingSize);
    for (i = 0; i < Cudd_ReadSize(dd); i++) {
	(void) fprintf(stdout,"v[%d]",i);
	Cudd_PrintDebug(dd, vector[i], Cudd_ReadSize(dd), 1);
	if (pr > 1) {
	    Cudd_bddPrintCover(dd, vector[i], vector[i]);
	}
    }
    verify = Cudd_bddVectorCompose(dd,f,vector);
    if (verify != Cudd_ReadOne(dd)) {
	(void) fprintf(stdout, "Verification failed!\n");
	return(0);
    }
    Cudd_Ref(verify);
    Cudd_IterDerefBdd(dd, verify);
    for (i = 0; i < Cudd_ReadSize(dd); i++) {
	Cudd_IterDerefBdd(dd, vector[i]);
    }
    FREE(vector);
    return(1);

} /* end of ntrTestCharToVect */


#if 0
/**
  @brief Try hard to squeeze a %BDD.

  @return a pointer to the squeezed %BDD if successful; NULL otherwise.

  @sideeffect None

  @see ntrTestDensityAux Cudd_SubsetCompress

*/
static DdNode *
ntrCompress1(
  DdManager * dd,
  DdNode * f,
  int  nvars,
  int  threshold)
{
    DdNode *res, *tmp1, *tmp2;
    int sizeI, size;

    tmp1 = Cudd_RemapUnderApprox(dd,f,nvars,0,1.0);
    if (tmp1 == NULL) return(NULL);
    Cudd_Ref(tmp1);
    sizeI = Cudd_DagSize(tmp1);
    size = (sizeI < threshold) ? sizeI : threshold;
    tmp2 = Cudd_SubsetShortPaths(dd, tmp1, nvars, size, 0);
    if (tmp2 == NULL) {
	Cudd_RecursiveDeref(dd,tmp1);
	return(NULL);
    }
    Cudd_Ref(tmp2);
    Cudd_RecursiveDeref(dd,tmp1);
    res = Cudd_bddSqueeze(dd,tmp2,f);
    if (res == NULL) {
	Cudd_RecursiveDeref(dd,tmp2);
	return(NULL);
    }
    Cudd_Ref(res);
    Cudd_RecursiveDeref(dd,tmp2);
    return(res);

} /* end of ntrCompress1 */
#endif


/**
  @brief Try hard to squeeze a %BDD.

  @return a pointer to the squeezed %BDD if successful; NULL otherwise.

  @sideeffect None

  @see ntrTestDensityAux Cudd_SubsetCompress

*/
static DdNode *
ntrCompress2(
  DdManager * dd,
  DdNode * f,
  int  nvars,
  int  threshold)
{
    DdNode *res, *tmp1, *tmp2;
    int sizeI;

    tmp1 = Cudd_RemapUnderApprox(dd,f,nvars,0,1.0);
    if (tmp1 == NULL) return(NULL);
    Cudd_Ref(tmp1);
    sizeI = Cudd_DagSize(tmp1);
    if (sizeI > threshold) {
	tmp2 = Cudd_SubsetShortPaths(dd, tmp1, nvars, threshold, 0);
	if (tmp2 == NULL) {
	    Cudd_RecursiveDeref(dd,tmp1);
	    return(NULL);
	}
	Cudd_Ref(tmp2);
	Cudd_RecursiveDeref(dd,tmp1);
    } else {
	tmp2 = tmp1;
    }
    res = Cudd_bddSqueeze(dd,tmp2,f);
    if (res == NULL) {
	Cudd_RecursiveDeref(dd,tmp2);
	return(NULL);
    }
    Cudd_Ref(res);
    if (Cudd_Density(dd,res,nvars) < Cudd_Density(dd,tmp2,nvars)) {
	Cudd_RecursiveDeref(dd,res);
	return(tmp2);
    } else {
	Cudd_RecursiveDeref(dd,tmp2);
	return(res);
    }

} /* end of ntrCompress2 */


/**
  @brief Checks whether node is a buffer.

  @return a pointer to the input node if nd is a buffer; NULL
  otherwise.

  @sideeffect None

*/
static BnetNode *
ntrNodeIsBuffer(
  BnetNode *nd,
  st_table *hash)
{
    BnetNode *inpnd;

    if (nd->ninp != 1) return(0);
    if (!st_lookup(hash, nd->inputs[0], (void **) &inpnd)) return(0);

    return(nd->dd == inpnd->dd ? inpnd : NULL);

} /* end of ntrNodeIsBuffer */