allow negative powers

[barvinok.git] / barvinok.cc

#include <assert.h>
#include <iostream>
#include <vector>
#include <deque>
#include <string>
#include <sstream>
#include <gmp.h>
#include <NTL/mat_ZZ.h>
#include <NTL/LLL.h>
#include <util.h>
extern "C" {
#include <polylib/polylibgmp.h>
#include "ev_operations.h"
#include "piputil.h"
}
#include "config.h"
#include <barvinok.h>

#ifdef NTL_STD_CXX
using namespace NTL;
#endif
using std::cout;
using std::endl;
using std::vector;
using std::deque;
using std::string;
using std::ostringstream;

#define ALLOC(p) (((long *) (p))[0])
#define SIZE(p) (((long *) (p))[1])
#define DATA(p) ((mp_limb_t *) (((long *) (p)) + 2))

static void value2zz(Value v, ZZ& z)
{
    int sa = v[0]._mp_size;
    int abs_sa = sa < 0 ? -sa : sa;

    _ntl_gsetlength(&z.rep, abs_sa);
    mp_limb_t * adata = DATA(z.rep);
    for (int i = 0; i < abs_sa; ++i)
        adata[i] = v[0]._mp_d[i];
    SIZE(z.rep) = sa;
}

static void zz2value(ZZ& z, Value& v)
{
    if (!z.rep) {
        value_set_si(v, 0);
        return;
    }

    int sa = SIZE(z.rep);
    int abs_sa = sa < 0 ? -sa : sa;

    mp_limb_t * adata = DATA(z.rep);
    _mpz_realloc(v, abs_sa);
    for (int i = 0; i < abs_sa; ++i)
        v[0]._mp_d[i] = adata[i];
    v[0]._mp_size = sa;
}

#undef ALLOC
#define ALLOC(t,p) p = (t*)malloc(sizeof(*p))

/*
 * We just ignore the last column and row
 * If the final element is not equal to one
 * then the result will actually be a multiple of the input
 */
static void matrix2zz(Matrix *M, mat_ZZ& m, unsigned nr, unsigned nc)
{
    m.SetDims(nr, nc);

    for (int i = 0; i < nr; ++i) {
//      assert(value_one_p(M->p[i][M->NbColumns - 1]));
        for (int j = 0; j < nc; ++j) {
            value2zz(M->p[i][j], m[i][j]);
        }
    }
}

static void values2zz(Value *p, vec_ZZ& v, int len)
{
    v.SetLength(len);

    for (int i = 0; i < len; ++i) {
        value2zz(p[i], v[i]);
    }
}

/*
 */
static void zz2values(vec_ZZ& v, Value *p)
{
    for (int i = 0; i < v.length(); ++i)
        zz2value(v[i], p[i]);
}

static void rays(mat_ZZ& r, Polyhedron *C)
{
    unsigned dim = C->NbRays - 1; /* don't count zero vertex */
    assert(C->NbRays - 1 == C->Dimension);
    r.SetDims(dim, dim);
    ZZ tmp;

    int i, c;
    for (i = 0, c = 0; i < dim; ++i)
        if (value_zero_p(C->Ray[i][dim+1])) {
            for (int j = 0; j < dim; ++j) {
                value2zz(C->Ray[i][j+1], tmp);
                r[j][c] = tmp;
            }
            ++c;
        }
}

static Matrix * rays(Polyhedron *C)
{
    unsigned dim = C->NbRays - 1; /* don't count zero vertex */
    assert(C->NbRays - 1 == C->Dimension);

    Matrix *M = Matrix_Alloc(dim+1, dim+1);
    assert(M);

    int i, c;
    for (i = 0, c = 0; i <= dim && c < dim; ++i)
        if (value_zero_p(C->Ray[i][dim+1])) {
            Vector_Copy(C->Ray[i] + 1, M->p[c], dim);
            value_set_si(M->p[c++][dim], 0);
        }
    assert(c == dim);
    value_set_si(M->p[dim][dim], 1);

    return M;
}

static Matrix * rays2(Polyhedron *C)
{
    unsigned dim = C->NbRays - 1; /* don't count zero vertex */
    assert(C->NbRays - 1 == C->Dimension);

    Matrix *M = Matrix_Alloc(dim, dim);
    assert(M);

    int i, c;
    for (i = 0, c = 0; i <= dim && c < dim; ++i)
        if (value_zero_p(C->Ray[i][dim+1]))
            Vector_Copy(C->Ray[i] + 1, M->p[c++], dim);
    assert(c == dim);

    return M;
}

/*
 * Returns the largest absolute value in the vector
 */
static ZZ max(vec_ZZ& v)
{
    ZZ max = abs(v[0]);
    for (int i = 1; i < v.length(); ++i)
        if (abs(v[i]) > max)
            max = abs(v[i]);
    return max;
}

class cone {
public:
    cone(Matrix *M) {
        Cone = 0;
        Rays = Matrix_Copy(M);
        set_det();
    }
    cone(Polyhedron *C) {
        Cone = Polyhedron_Copy(C);
        Rays = rays(C);
        set_det();
    }
    void set_det() {
        mat_ZZ A;
        matrix2zz(Rays, A, Rays->NbRows - 1, Rays->NbColumns - 1);
        det = determinant(A);
        Value v;
        value_init(v);
        zz2value(det, v);
        value_clear(v);
    }

    Vector* short_vector(vec_ZZ& lambda) {
        Matrix *M = Matrix_Copy(Rays);
        Matrix *inv = Matrix_Alloc(M->NbRows, M->NbColumns);
        int ok = Matrix_Inverse(M, inv);
        assert(ok);
        Matrix_Free(M);

        ZZ det2;
        mat_ZZ B;
        mat_ZZ U;
        matrix2zz(inv, B, inv->NbRows - 1, inv->NbColumns - 1);
        long r = LLL(det2, B, U);

        ZZ min = max(B[0]);
        int index = 0;
        for (int i = 1; i < B.NumRows(); ++i) {
            ZZ tmp = max(B[i]);
            if (tmp < min) {
                min = tmp;
                index = i;
            }
        }

        Matrix_Free(inv);

        lambda = B[index];

        Vector *z = Vector_Alloc(U[index].length()+1);
        assert(z);
        zz2values(U[index], z->p);
        value_set_si(z->p[U[index].length()], 0);

        Value tmp;
        value_init(tmp);
        Polyhedron *C = poly();
        int i;
        for (i = 0; i < C->NbConstraints; ++i) {
            Inner_Product(z->p, C->Constraint[i]+1, z->Size-1, &tmp);
            if (value_pos_p(tmp))
                break;
        }
        if (i == C->NbConstraints) {
            value_set_si(tmp, -1);
            Vector_Scale(z->p, z->p, tmp, z->Size-1);
        }
        value_clear(tmp);
        return z;
    }

    ~cone() {
        Polyhedron_Free(Cone);
        Matrix_Free(Rays);
    }

    Polyhedron *poly() {
        if (!Cone) {
            Matrix *M = Matrix_Alloc(Rays->NbRows+1, Rays->NbColumns+1);
            for (int i = 0; i < Rays->NbRows; ++i) {
                Vector_Copy(Rays->p[i], M->p[i]+1, Rays->NbColumns);
                value_set_si(M->p[i][0], 1);
            }
            Vector_Set(M->p[Rays->NbRows]+1, 0, Rays->NbColumns-1);
            value_set_si(M->p[Rays->NbRows][0], 1);
            value_set_si(M->p[Rays->NbRows][Rays->NbColumns], 1);
            Cone = Rays2Polyhedron(M, M->NbRows+1);
            assert(Cone->NbConstraints == Cone->NbRays);
            Matrix_Free(M);
        }
        return Cone;
    }

    ZZ det;
    Polyhedron *Cone;
    Matrix *Rays;
};

class dpoly {
public:
    vec_ZZ coeff;
    dpoly(int d, ZZ& degree, int offset = 0) {
        coeff.SetLength(d+1);

        int min = d + offset;
        if (degree >= 0 && degree < ZZ(INIT_VAL, min))
            min = to_int(degree);

        ZZ c = ZZ(INIT_VAL, 1);
        if (!offset)
            coeff[0] = c;
        for (int i = 1; i <= min; ++i) {
            c *= (degree -i + 1);
            c /= i;
            coeff[i-offset] = c;
        }
    }
    void operator *= (dpoly& f) {
        assert(coeff.length() == f.coeff.length());
        vec_ZZ old = coeff;
        coeff = f.coeff[0] * coeff;
        for (int i = 1; i < coeff.length(); ++i)
            for (int j = 0; i+j < coeff.length(); ++j)
                coeff[i+j] += f.coeff[i] * old[j];
    }
    void div(dpoly& d, mpq_t count, ZZ& sign) {
        int len = coeff.length();
        Value tmp;
        value_init(tmp);
        mpq_t* c = new mpq_t[coeff.length()];
        mpq_t qtmp;
        mpq_init(qtmp);
        for (int i = 0; i < len; ++i) {
            mpq_init(c[i]);
            zz2value(coeff[i], tmp);
            mpq_set_z(c[i], tmp);

            for (int j = 1; j <= i; ++j) {
                zz2value(d.coeff[j], tmp);
                mpq_set_z(qtmp, tmp);
                mpq_mul(qtmp, qtmp, c[i-j]);
                mpq_sub(c[i], c[i], qtmp);
            }

            zz2value(d.coeff[0], tmp);
            mpq_set_z(qtmp, tmp);
            mpq_div(c[i], c[i], qtmp);
        }
        if (sign == -1)
            mpq_sub(count, count, c[len-1]);
        else
            mpq_add(count, count, c[len-1]);

        value_clear(tmp);
        mpq_clear(qtmp);
        for (int i = 0; i < len; ++i)
            mpq_clear(c[i]);
        delete [] c;
    }
};

class dpoly_n {
public:
    Matrix *coeff;
    ~dpoly_n() {
        Matrix_Free(coeff);
    }
    dpoly_n(int d, ZZ& degree_0, ZZ& degree_1, int offset = 0) {
        Value d0, d1;
        value_init(d0);
        value_init(d1);
        zz2value(degree_0, d0);
        zz2value(degree_1, d1);
        coeff = Matrix_Alloc(d+1, d+1+1);
        value_set_si(coeff->p[0][0], 1);
        value_set_si(coeff->p[0][d+1], 1);
        for (int i = 1; i <= d; ++i) {
            value_multiply(coeff->p[i][0], coeff->p[i-1][0], d0);
            Vector_Combine(coeff->p[i-1], coeff->p[i-1]+1, coeff->p[i]+1,
                           d1, d0, i);
            value_set_si(coeff->p[i][d+1], i);
            value_multiply(coeff->p[i][d+1], coeff->p[i][d+1], coeff->p[i-1][d+1]);
            value_decrement(d0, d0);
        }
        value_clear(d0);
        value_clear(d1);
    }
    void div(dpoly& d, Vector *count, ZZ& sign) {
        int len = coeff->NbRows;
        Matrix * c = Matrix_Alloc(coeff->NbRows, coeff->NbColumns);
        Value tmp;
        value_init(tmp);
        for (int i = 0; i < len; ++i) {
            Vector_Copy(coeff->p[i], c->p[i], len+1);
            for (int j = 1; j <= i; ++j) {
                zz2value(d.coeff[j], tmp);
                value_multiply(tmp, tmp, c->p[i][len]);
                value_oppose(tmp, tmp);
                Vector_Combine(c->p[i], c->p[i-j], c->p[i],
                               c->p[i-j][len], tmp, len);
                value_multiply(c->p[i][len], c->p[i][len], c->p[i-j][len]);
            }
            zz2value(d.coeff[0], tmp);
            value_multiply(c->p[i][len], c->p[i][len], tmp);
        }
        if (sign == -1) {
            value_set_si(tmp, -1);
            Vector_Scale(c->p[len-1], count->p, tmp, len);
            value_assign(count->p[len], c->p[len-1][len]);
        } else
            Vector_Copy(c->p[len-1], count->p, len+1);
        Vector_Normalize(count->p, len+1);
        value_clear(tmp);
        Matrix_Free(c);
    }
};

/*
 * Barvinok's Decomposition of a simplicial cone
 *
 * Returns two lists of polyhedra
 */
void barvinok_decompose(Polyhedron *C, Polyhedron **ppos, Polyhedron **pneg)
{
    Polyhedron *pos = *ppos, *neg = *pneg;
    vector<cone *> nonuni;
    cone * c = new cone(C);
    ZZ det = c->det;
    int s = sign(det);
    assert(det != 0);
    if (abs(det) > 1) {
        nonuni.push_back(c);
    } else {
        Polyhedron *p = Polyhedron_Copy(c->Cone);
        p->next = pos;
        pos = p;
        delete c;
    }
    vec_ZZ lambda;
    while (!nonuni.empty()) {
        c = nonuni.back();
        nonuni.pop_back();
        Vector* v = c->short_vector(lambda);
        for (int i = 0; i < c->Rays->NbRows - 1; ++i) {
            if (lambda[i] == 0)
                continue;
            Matrix* M = Matrix_Copy(c->Rays);
            Vector_Copy(v->p, M->p[i], v->Size);
            cone * pc = new cone(M);
            assert (pc->det != 0);
            if (abs(pc->det) > 1) {
                assert(abs(pc->det) < abs(c->det));
                nonuni.push_back(pc);
            } else {
                Polyhedron *p = pc->poly();
                pc->Cone = 0;
                if (sign(pc->det) == s) {
                    p->next = pos;
                    pos = p;
                } else {
                    p->next = neg;
                    neg = p;
                }
                delete pc;
            }
            Matrix_Free(M);
        }
        Vector_Free(v);
        delete c;
    }
    *ppos = pos;
    *pneg = neg;
}

/*
 *  Returns a single list of npos "positive" cones followed by nneg
 *  "negative" cones.
 *  The input cone is freed
 */
void decompose(Polyhedron *cone, Polyhedron **parts, int *npos, int *nneg, unsigned MaxRays)
{
    Polyhedron_Polarize(cone);
    if (cone->NbRays - 1 != cone->Dimension) {
        Polyhedron *tmp = cone;
        cone = triangularize_cone(cone, MaxRays);
        Polyhedron_Free(tmp);
    }
    Polyhedron *polpos = NULL, *polneg = NULL;
    *npos = 0; *nneg = 0;
    for (Polyhedron *Polar = cone; Polar; Polar = Polar->next)
        barvinok_decompose(Polar, &polpos, &polneg);

    Polyhedron *last;
    for (Polyhedron *i = polpos; i; i = i->next) {
        Polyhedron_Polarize(i);
        ++*npos;
        last = i;
    }
    for (Polyhedron *i = polneg; i; i = i->next) {
        Polyhedron_Polarize(i);
        ++*nneg;
    }
    if (last) {
        last->next = polneg;
        *parts = polpos;
    } else
        *parts = polneg;
    Domain_Free(cone);
}

const int MAX_TRY=10;
/*
 * Searches for a vector that is not othogonal to any
 * of the rays in rays.
 */
static void nonorthog(mat_ZZ& rays, vec_ZZ& lambda)
{
    int dim = rays.NumCols();
    bool found = false;
    lambda.SetLength(dim);
    for (int i = 2; !found && i <= 50*dim; i+=4) {
        for (int j = 0; j < MAX_TRY; ++j) {
            for (int k = 0; k < dim; ++k) {
                int r = random_int(i)+2;
                int v = (2*(r%2)-1) * (r >> 1);
                lambda[k] = v;
            }
            int k = 0;
            for (; k < rays.NumRows(); ++k)
                if (lambda * rays[k] == 0)
                    break;
            if (k == rays.NumRows()) {
                found = true;
                break;
            }
        }
    }
    assert(found);
}

static void add_rays(mat_ZZ& rays, Polyhedron *i, int *r)
{
    unsigned dim = i->Dimension;
    for (int k = 0; k < i->NbRays; ++k) {
        if (!value_zero_p(i->Ray[k][dim+1]))
            continue;
        values2zz(i->Ray[k]+1, rays[(*r)++], dim);
    }
}

void lattice_point(Value* values, Polyhedron *i, vec_ZZ& lambda, ZZ& num)
{
    vec_ZZ vertex;
    unsigned dim = i->Dimension;
    if(!value_one_p(values[dim])) {
        Matrix* Rays = rays(i);
        Matrix *inv = Matrix_Alloc(Rays->NbRows, Rays->NbColumns);
        int ok = Matrix_Inverse(Rays, inv);
        assert(ok);
        Matrix_Free(Rays);
        Rays = rays(i);
        Vector *lambda = Vector_Alloc(dim+1);
        Vector_Matrix_Product(values, inv, lambda->p);
        Matrix_Free(inv);
        for (int j = 0; j < dim; ++j)
            mpz_cdiv_q(lambda->p[j], lambda->p[j], lambda->p[dim]);
        value_set_si(lambda->p[dim], 1);
        Vector *A = Vector_Alloc(dim+1);
        Vector_Matrix_Product(lambda->p, Rays, A->p);
        Vector_Free(lambda);
        Matrix_Free(Rays);
        values2zz(A->p, vertex, dim);
        Vector_Free(A);
    } else
        values2zz(values, vertex, dim);

    num = vertex * lambda;
}

static evalue *term(int param, ZZ& c, Value *den = NULL)
{
    evalue *EP = new evalue();
    value_init(EP->d);
    value_set_si(EP->d,0);
    EP->x.p = new_enode(polynomial, 2, param + 1);
    evalue_set_si(&EP->x.p->arr[0], 0, 1);
    value_init(EP->x.p->arr[1].x.n);
    if (den == NULL)
        value_set_si(EP->x.p->arr[1].d, 1);
    else
        value_assign(EP->x.p->arr[1].d, *den);
    zz2value(c, EP->x.p->arr[1].x.n);
    return EP;
}

static void vertex_period(
                    Polyhedron *i, vec_ZZ& lambda, Matrix *T, 
                    Value lcm, int p, Vector *val, 
                    evalue *E, evalue* ev,
                    ZZ& offset)
{
    unsigned nparam = T->NbRows - 1;
    unsigned dim = i->Dimension;
    Value tmp;
    ZZ nump;

    if (p == nparam) {
        ZZ num, l;
        Vector * values = Vector_Alloc(dim + 1);
        Vector_Matrix_Product(val->p, T, values->p);
        value_assign(values->p[dim], lcm);
        lattice_point(values->p, i, lambda, num);
        value2zz(lcm, l);
        num *= l;
        num += offset;
        value_init(ev->x.n);
        zz2value(num, ev->x.n);
        value_assign(ev->d, lcm);
        Vector_Free(values);
        return;
    }

    value_init(tmp);
    vec_ZZ vertex;
    values2zz(T->p[p], vertex, dim);
    nump = vertex * lambda;
    if (First_Non_Zero(val->p, p) == -1) {
        value_assign(tmp, lcm);
        evalue *ET = term(p, nump, &tmp);
        eadd(ET, E);   
        free_evalue_refs(ET); 
        delete ET;
    }

    value_assign(tmp, lcm);
    if (First_Non_Zero(T->p[p], dim) != -1)
        Vector_Gcd(T->p[p], dim, &tmp);
    Gcd(tmp, lcm, &tmp);
    if (value_lt(tmp, lcm)) {
        ZZ count;

        value_division(tmp, lcm, tmp);
        value_set_si(ev->d, 0);
        ev->x.p = new_enode(periodic, VALUE_TO_INT(tmp), p+1);
        value2zz(tmp, count);
        do {
            value_decrement(tmp, tmp);
            --count;
            ZZ new_offset = offset - count * nump;
            value_assign(val->p[p], tmp);
            vertex_period(i, lambda, T, lcm, p+1, val, E, 
                          &ev->x.p->arr[VALUE_TO_INT(tmp)], new_offset);
        } while (value_pos_p(tmp));
    } else
        vertex_period(i, lambda, T, lcm, p+1, val, E, ev, offset);
    value_clear(tmp);
}

static void mask_r(Matrix *f, int nr, Vector *lcm, int p, Vector *val, evalue *ev)
{
    unsigned nparam = lcm->Size;

    if (p == nparam) {
        Vector * prod = Vector_Alloc(f->NbRows);
        Matrix_Vector_Product(f, val->p, prod->p);
        int isint = 1;
        for (int i = 0; i < nr; ++i) {
            value_modulus(prod->p[i], prod->p[i], f->p[i][nparam+1]);
            isint &= value_zero_p(prod->p[i]);
        }
        value_set_si(ev->d, 1);
        value_init(ev->x.n);
        value_set_si(ev->x.n, isint);
        Vector_Free(prod);
        return;
    }

    Value tmp;
    value_init(tmp);
    if (value_one_p(lcm->p[p]))
        mask_r(f, nr, lcm, p+1, val, ev);
    else { 
        value_assign(tmp, lcm->p[p]);
        value_set_si(ev->d, 0);
        ev->x.p = new_enode(periodic, VALUE_TO_INT(tmp), p+1);
        do {
            value_decrement(tmp, tmp);
            value_assign(val->p[p], tmp);
            mask_r(f, nr, lcm, p+1, val, &ev->x.p->arr[VALUE_TO_INT(tmp)]);
        } while (value_pos_p(tmp));
    }
    value_clear(tmp);
}

static evalue *multi_monom(vec_ZZ& p)
{
    evalue *X = new evalue();
    value_init(X->d);
    value_init(X->x.n);
    unsigned nparam = p.length()-1;
    zz2value(p[nparam], X->x.n);
    value_set_si(X->d, 1);
    for (int i = 0; i < nparam; ++i) {
        if (p[i] == 0)
            continue;
        evalue *T = term(i, p[i]);
        eadd(T, X); 
        free_evalue_refs(T); 
        delete T;
    }
    return X;
}

/*
 * Check whether mapping polyhedron P on the affine combination
 * num yields a range that has a fixed quotient on integer
 * division by d
 * If zero is true, then we are only interested in the quotient
 * for the cases where the remainder is zero.
 * Returns NULL if false and a newly allocated value if true.
 */
static Value *fixed_quotient(Polyhedron *P, vec_ZZ& num, Value d, bool zero)
{
    Value* ret = NULL;
    int len = num.length();
    Matrix *T = Matrix_Alloc(2, len);
    zz2values(num, T->p[0]);
    value_set_si(T->p[1][len-1], 1);
    Polyhedron *I = Polyhedron_Image(P, T, P->NbConstraints);
    Matrix_Free(T);

    int i;
    for (i = 0; i < I->NbRays; ++i)
        if (value_zero_p(I->Ray[i][2])) {
            Polyhedron_Free(I);
            return NULL;
        }

    Value min, max;
    value_init(min);
    value_init(max);
    int bounded = line_minmax(I, &min, &max);
    assert(bounded);

    if (zero)
        mpz_cdiv_q(min, min, d);
    else
        mpz_fdiv_q(min, min, d);
    mpz_fdiv_q(max, max, d);

    if (value_eq(min, max)) {
        ALLOC(Value, ret);
        value_init(*ret);
        value_assign(*ret, min);
    } 
    value_clear(min);
    value_clear(max);
    return ret;
}

/*
 * Normalize linear expression coef modulo m
 * Removes common factor and reduces coefficients
 * Returns index of first non-zero coefficient or len
 */
static int normal_mod(Value *coef, int len, Value *m)
{
    Value gcd;
    value_init(gcd);

    Vector_Gcd(coef, len, &gcd);
    Gcd(gcd, *m, &gcd);
    Vector_AntiScale(coef, coef, gcd, len);

    value_division(*m, *m, gcd);
    value_clear(gcd);

    if (value_one_p(*m))
        return len;

    int j;
    for (j = 0; j < len; ++j)
        mpz_fdiv_r(coef[j], coef[j], *m);
    for (j = 0; j < len; ++j)
        if (value_notzero_p(coef[j]))
            break;

    return j;
}

#ifdef USE_MODULO
static void mask(Matrix *f, evalue *factor)
{
    int nr = f->NbRows, nc = f->NbColumns;
    int n;
    bool found = false;
    for (n = 0; n < nr && value_notzero_p(f->p[n][nc-1]); ++n)
        if (value_notone_p(f->p[n][nc-1]) &&
            value_notmone_p(f->p[n][nc-1]))
                found = true;
    if (!found)
        return;

    evalue EP;
    nr = n;

    Value m;
    value_init(m);

    evalue EV;
    value_init(EV.d);
    value_init(EV.x.n);
    value_set_si(EV.x.n, 1);

    for (n = 0; n < nr; ++n) {
        value_assign(m, f->p[n][nc-1]);
        if (value_one_p(m) || value_mone_p(m))
            continue;

        int j = normal_mod(f->p[n], nc-1, &m);
        if (j == nc-1) {
            free_evalue_refs(factor);
            value_init(factor->d);
            evalue_set_si(factor, 0, 1);
            break;
        }
        vec_ZZ row;
        values2zz(f->p[n], row, nc-1);
        ZZ g;
        value2zz(m, g);
        if (j < (nc-1)-1 && row[j] > g/2) {
            for (int k = j; k < (nc-1); ++k)
                if (row[k] != 0)
                    row[k] = g - row[k];
        }

        value_init(EP.d);
        value_set_si(EP.d, 0);
        EP.x.p = new_enode(relation, 2, 0);
        value_clear(EP.x.p->arr[1].d);
        EP.x.p->arr[1] = *factor;
        evalue *ev = &EP.x.p->arr[0];
        value_set_si(ev->d, 0);
        ev->x.p = new_enode(fractional, 3, -1);
        evalue_set_si(&ev->x.p->arr[1], 0, 1);
        evalue_set_si(&ev->x.p->arr[2], 1, 1);
        evalue *E = multi_monom(row);
        value_assign(EV.d, m);
        emul(&EV, E);
        value_clear(ev->x.p->arr[0].d);
        ev->x.p->arr[0] = *E;
        delete E;
        *factor = EP;
    }

    value_clear(m);
    free_evalue_refs(&EV); 
}
#else
/*
 * 
 */
static void mask(Matrix *f, evalue *factor)
{
    int nr = f->NbRows, nc = f->NbColumns;
    int n;
    bool found = false;
    for (n = 0; n < nr && value_notzero_p(f->p[n][nc-1]); ++n)
        if (value_notone_p(f->p[n][nc-1]) &&
            value_notmone_p(f->p[n][nc-1]))
                found = true;
    if (!found)
        return;

    Value tmp;
    value_init(tmp);
    nr = n;
    unsigned np = nc - 2;
    Vector *lcm = Vector_Alloc(np);
    Vector *val = Vector_Alloc(nc);
    Vector_Set(val->p, 0, nc);
    value_set_si(val->p[np], 1);
    Vector_Set(lcm->p, 1, np);
    for (n = 0; n < nr; ++n) {
        if (value_one_p(f->p[n][nc-1]) ||
            value_mone_p(f->p[n][nc-1]))
            continue;
        for (int j = 0; j < np; ++j)
            if (value_notzero_p(f->p[n][j])) {
                Gcd(f->p[n][j], f->p[n][nc-1], &tmp);
                value_division(tmp, f->p[n][nc-1], tmp);
                value_lcm(tmp, lcm->p[j], &lcm->p[j]);
            }
    }
    evalue EP;
    value_init(EP.d);
    mask_r(f, nr, lcm, 0, val, &EP);
    value_clear(tmp);
    Vector_Free(val);
    Vector_Free(lcm);
    emul(&EP,factor); 
    free_evalue_refs(&EP);
}
#endif

struct term_info {
    evalue         *E;
    ZZ              constant;
    ZZ              coeff;
    int             pos;
};

static bool mod_needed(Polyhedron *PD, vec_ZZ& num, Value d, evalue *E)
{
    Value *q = fixed_quotient(PD, num, d, false);

    if (!q)
        return true;

    value_oppose(*q, *q);
    evalue EV;
    value_init(EV.d);
    value_set_si(EV.d, 1);
    value_init(EV.x.n);
    value_multiply(EV.x.n, *q, d);
    eadd(&EV, E);
    free_evalue_refs(&EV); 
    value_clear(*q);
    free(q);
    return false;
}

static void ceil_mod(Value *coef, int len, Value d, ZZ& f, evalue *EP, Polyhedron *PD)
{
    Value m;
    value_init(m);
    value_set_si(m, -1);

    Vector_Scale(coef, coef, m, len);

    value_assign(m, d);
    int j = normal_mod(coef, len, &m);

    if (j == len) {
        value_clear(m);
        return;
    }

    vec_ZZ num;
    values2zz(coef, num, len);

    ZZ g;
    value2zz(m, g);

    evalue tmp;
    value_init(tmp.d);
    evalue_set_si(&tmp, 0, 1);

    int p = j;
    if (g % 2 == 0)
        while (j < len-1 && (num[j] == g/2 || num[j] == 0))
            ++j;
    if ((j < len-1 && num[j] > g/2) || (j == len-1 && num[j] >= (g+1)/2)) {
        for (int k = j; k < len-1; ++k)
            if (num[k] != 0)
                num[k] = g - num[k];
        num[len-1] = g - 1 - num[len-1];
        value_assign(tmp.d, m);
        ZZ t = f*(g-1);
        zz2value(t, tmp.x.n);
        eadd(&tmp, EP);
        f = -f;
    }

    if (p >= len-1) {
        ZZ t = num[len-1] * f;
        zz2value(t, tmp.x.n);
        value_assign(tmp.d, m);
        eadd(&tmp, EP);
    } else {
        evalue *E = multi_monom(num);
        evalue EV;
        value_init(EV.d);

        if (PD && !mod_needed(PD, num, m, E)) {
            value_init(EV.x.n);
            zz2value(f, EV.x.n);
            value_assign(EV.d, m);
            emul(&EV, E);
            eadd(E, EP);
        } else {
            value_init(EV.x.n);
            value_set_si(EV.x.n, 1);
            value_assign(EV.d, m);
            emul(&EV, E);
            value_clear(EV.x.n);
            value_set_si(EV.d, 0);
            EV.x.p = new_enode(fractional, 3, -1);
            evalue_copy(&EV.x.p->arr[0], E);
            evalue_set_si(&EV.x.p->arr[1], 0, 1);
            value_init(EV.x.p->arr[2].x.n);
            zz2value(f, EV.x.p->arr[2].x.n);
            value_set_si(EV.x.p->arr[2].d, 1);

            eadd(&EV, EP);
        }

        free_evalue_refs(&EV); 
        free_evalue_refs(E); 
        delete E;
    }

    free_evalue_refs(&tmp); 

out:
    value_clear(m);
}

evalue* bv_ceil3(Value *coef, int len, Value d, Polyhedron *P)
{
    Vector *val = Vector_Alloc(len);

    Value t;
    value_init(t);
    value_set_si(t, -1);
    Vector_Scale(coef, val->p, t, len);
    value_absolute(t, d);

    vec_ZZ num;
    values2zz(val->p, num, len);
    evalue *EP = multi_monom(num);

    evalue tmp;
    value_init(tmp.d);
    value_init(tmp.x.n);
    value_set_si(tmp.x.n, 1);
    value_assign(tmp.d, t);

    emul(&tmp, EP);

    ZZ one;
    one = 1;
    ceil_mod(val->p, len, t, one, EP, P);
    value_clear(t);

    /* copy EP to malloc'ed evalue */
    evalue *E;
    ALLOC(evalue, E);
    *E = *EP;
    delete EP;

    free_evalue_refs(&tmp); 
    Vector_Free(val);

    return E;
}

#ifdef USE_MODULO
evalue* lattice_point(
    Polyhedron *i, vec_ZZ& lambda, Matrix *W, Value lcm, Polyhedron *PD)
{
    unsigned nparam = W->NbColumns - 1;

    Matrix* Rays = rays2(i);
    Matrix *T = Transpose(Rays);
    Matrix *T2 = Matrix_Copy(T);
    Matrix *inv = Matrix_Alloc(T2->NbRows, T2->NbColumns);
    int ok = Matrix_Inverse(T2, inv);
    assert(ok);
    Matrix_Free(Rays);
    Matrix_Free(T2);
    mat_ZZ vertex;
    matrix2zz(W, vertex, W->NbRows, W->NbColumns);

    vec_ZZ num;
    num = lambda * vertex;

    evalue *EP = multi_monom(num);

    evalue tmp;
    value_init(tmp.d);
    value_init(tmp.x.n);
    value_set_si(tmp.x.n, 1);
    value_assign(tmp.d, lcm);

    emul(&tmp, EP);

    Matrix *L = Matrix_Alloc(inv->NbRows, W->NbColumns);
    Matrix_Product(inv, W, L);

    mat_ZZ RT;
    matrix2zz(T, RT, T->NbRows, T->NbColumns);
    Matrix_Free(T);

    vec_ZZ p = lambda * RT;

    for (int i = 0; i < L->NbRows; ++i) {
        ceil_mod(L->p[i], nparam+1, lcm, p[i], EP, PD);
    }

    Matrix_Free(L);

    Matrix_Free(inv);
    free_evalue_refs(&tmp); 
    return EP;
}
#else
evalue* lattice_point(
    Polyhedron *i, vec_ZZ& lambda, Matrix *W, Value lcm, Polyhedron *PD)
{
    Matrix *T = Transpose(W);
    unsigned nparam = T->NbRows - 1;

    evalue *EP = new evalue();
    value_init(EP->d);
    evalue_set_si(EP, 0, 1);

    evalue ev;
    Vector *val = Vector_Alloc(nparam+1);
    value_set_si(val->p[nparam], 1);
    ZZ offset(INIT_VAL, 0);
    value_init(ev.d);
    vertex_period(i, lambda, T, lcm, 0, val, EP, &ev, offset);
    Vector_Free(val);
    eadd(&ev, EP);
    free_evalue_refs(&ev);   

    Matrix_Free(T);

    reduce_evalue(EP);

    return EP;
}
#endif

void lattice_point(
    Param_Vertices* V, Polyhedron *i, vec_ZZ& lambda, term_info* term,
    Polyhedron *PD)
{
    unsigned nparam = V->Vertex->NbColumns - 2;
    unsigned dim = i->Dimension;
    mat_ZZ vertex;
    vertex.SetDims(V->Vertex->NbRows, nparam+1);
    Value lcm, tmp;
    value_init(lcm);
    value_init(tmp);
    value_set_si(lcm, 1);
    for (int j = 0; j < V->Vertex->NbRows; ++j) {
        value_lcm(lcm, V->Vertex->p[j][nparam+1], &lcm);
    }
    if (value_notone_p(lcm)) {
        Matrix * mv = Matrix_Alloc(dim, nparam+1);
        for (int j = 0 ; j < dim; ++j) {
            value_division(tmp, lcm, V->Vertex->p[j][nparam+1]);
            Vector_Scale(V->Vertex->p[j], mv->p[j], tmp, nparam+1);
        }

        term->E = lattice_point(i, lambda, mv, lcm, PD);
        term->constant = 0;

        Matrix_Free(mv);
        value_clear(lcm);
        value_clear(tmp);
        return;
    }
    for (int i = 0; i < V->Vertex->NbRows; ++i) {
        assert(value_one_p(V->Vertex->p[i][nparam+1]));  // for now
        values2zz(V->Vertex->p[i], vertex[i], nparam+1);
    }

    vec_ZZ num;
    num = lambda * vertex;

    int p = -1;
    int nn = 0;
    for (int j = 0; j < nparam; ++j)
        if (num[j] != 0) {
            ++nn;
            p = j;
        }
    if (nn >= 2) {
        term->E = multi_monom(num);
        term->constant = 0;
    } else {
        term->E = NULL;
        term->constant = num[nparam];
        term->pos = p;
        if (p != -1)
            term->coeff = num[p];
    }

    value_clear(lcm);
    value_clear(tmp);
}

void normalize(Polyhedron *i, vec_ZZ& lambda, ZZ& sign, ZZ& num, vec_ZZ& den)
{
    unsigned dim = i->Dimension;

    int r = 0;
    mat_ZZ rays;
    rays.SetDims(dim, dim);
    add_rays(rays, i, &r);
    den = rays * lambda;
    int change = 0;

    for (int j = 0; j < den.length(); ++j) {
        if (den[j] > 0)
            change ^= 1;
        else {
            den[j] = abs(den[j]);
            num += den[j];
        }
    }
    if (change)
        sign = -sign;
}

typedef Polyhedron * Polyhedron_p;

void barvinok_count(Polyhedron *P, Value* result, unsigned NbMaxCons)
{
    Polyhedron ** vcone;
    vec_ZZ sign;
    int ncone = 0;
    sign.SetLength(ncone);
    unsigned dim;
    int allocated = 0;
    Value factor;
    Polyhedron *Q;
    int r = 0;

    if (emptyQ(P)) {
        value_set_si(*result, 0);
        return;
    }
    if (P->NbBid == 0)
        for (; r < P->NbRays; ++r)
            if (value_zero_p(P->Ray[r][P->Dimension+1]))
                break;
    if (P->NbBid !=0 || r < P->NbRays) {
        value_set_si(*result, -1);
        return;
    }
    if (P->NbEq != 0) {
        P = remove_equalities(P);
        if (emptyQ(P)) {
            Polyhedron_Free(P);
            value_set_si(*result, 0);
            return;
        }
        allocated = 1;
    }
    value_init(factor);
    value_set_si(factor, 1);
    Q = Polyhedron_Reduce(P, &factor);
    if (Q) {
        if (allocated)
            Polyhedron_Free(P);
        P = Q;
        allocated = 1;
    }
    if (P->Dimension == 0) {
        value_assign(*result, factor);
        if (allocated)
            Polyhedron_Free(P);
        value_clear(factor);
        return;
    }

    dim = P->Dimension;
    vcone = new Polyhedron_p[P->NbRays];

    for (int j = 0; j < P->NbRays; ++j) {
        int npos, nneg;
        Polyhedron *C = supporting_cone(P, j);
        decompose(C, &vcone[j], &npos, &nneg, NbMaxCons);
        ncone += npos + nneg;
        sign.SetLength(ncone);
        for (int k = 0; k < npos; ++k)
            sign[ncone-nneg-k-1] = 1;
        for (int k = 0; k < nneg; ++k)
            sign[ncone-k-1] = -1;
    }

    mat_ZZ rays;
    rays.SetDims(ncone * dim, dim);
    r = 0;
    for (int j = 0; j < P->NbRays; ++j) {
        for (Polyhedron *i = vcone[j]; i; i = i->next) {
            assert(i->NbRays-1 == dim);
            add_rays(rays, i, &r);
        }
    }
    vec_ZZ lambda;
    nonorthog(rays, lambda);

    vec_ZZ num;
    mat_ZZ den;
    num.SetLength(ncone);
    den.SetDims(ncone,dim);

    int f = 0;
    for (int j = 0; j < P->NbRays; ++j) {
        for (Polyhedron *i = vcone[j]; i; i = i->next) {
            lattice_point(P->Ray[j]+1, i, lambda, num[f]);
            normalize(i, lambda, sign[f], num[f], den[f]);
            ++f;
        }
    }
    ZZ min = num[0];
    for (int j = 1; j < num.length(); ++j)
        if (num[j] < min)
            min = num[j];
    for (int j = 0; j < num.length(); ++j)
        num[j] -= min;

    f = 0;
    mpq_t count;
    mpq_init(count);
    for (int j = 0; j < P->NbRays; ++j) {
        for (Polyhedron *i = vcone[j]; i; i = i->next) {
            dpoly d(dim, num[f]);
            dpoly n(dim, den[f][0], 1);
            for (int k = 1; k < dim; ++k) {
                dpoly fact(dim, den[f][k], 1);
                n *= fact;
            }
            d.div(n, count, sign[f]);
            ++f;
        }
    }
    assert(value_one_p(&count[0]._mp_den));
    value_multiply(*result, &count[0]._mp_num, factor);
    mpq_clear(count);

    for (int j = 0; j < P->NbRays; ++j)
        Domain_Free(vcone[j]);

    delete [] vcone;

    if (allocated)
        Polyhedron_Free(P);
    value_clear(factor);
}

static void uni_polynom(int param, Vector *c, evalue *EP)
{ 
    unsigned dim = c->Size-2;
    value_init(EP->d);
    value_set_si(EP->d,0);
    EP->x.p = new_enode(polynomial, dim+1, param+1);
    for (int j = 0; j <= dim; ++j)
        evalue_set(&EP->x.p->arr[j], c->p[j], c->p[dim+1]);
}

static void multi_polynom(Vector *c, evalue* X, evalue *EP)
{
    unsigned dim = c->Size-2;
    evalue EC;

    value_init(EC.d);
    evalue_set(&EC, c->p[dim], c->p[dim+1]);

    value_init(EP->d);
    evalue_set(EP, c->p[dim], c->p[dim+1]);
        
    for (int i = dim-1; i >= 0; --i) {
        emul(X, EP);       
        value_assign(EC.x.n, c->p[i]);
        eadd(&EC, EP);
    }
    free_evalue_refs(&EC);
}

Polyhedron *unfringe (Polyhedron *P, unsigned MaxRays)
{
    int len = P->Dimension+2;
    Polyhedron *T, *R = P;
    Value g;
    value_init(g);
    Vector *row = Vector_Alloc(len);
    value_set_si(row->p[0], 1);

    R = DomainConstraintSimplify(Polyhedron_Copy(P), MaxRays);

    Matrix *M = Matrix_Alloc(2, len-1);
    value_set_si(M->p[1][len-2], 1);
    for (int v = 0; v < P->Dimension; ++v) {
        value_set_si(M->p[0][v], 1);
        Polyhedron *I = Polyhedron_Image(P, M, 2+1);
        value_set_si(M->p[0][v], 0);
        for (int r = 0; r < I->NbConstraints; ++r) {
            if (value_zero_p(I->Constraint[r][0]))
                continue;
            if (value_zero_p(I->Constraint[r][1]))
                continue;
            if (value_one_p(I->Constraint[r][1]))
                continue;
            if (value_mone_p(I->Constraint[r][1]))
                continue;
            value_absolute(g, I->Constraint[r][1]);
            Vector_Set(row->p+1, 0, len-2);
            value_division(row->p[1+v], I->Constraint[r][1], g);
            mpz_fdiv_q(row->p[len-1], I->Constraint[r][2], g);
            T = R;
            R = AddConstraints(row->p, 1, R, MaxRays);
            if (T != P)
                Polyhedron_Free(T);
        }
        Polyhedron_Free(I);
    }
    Matrix_Free(M);
    Vector_Free(row);
    value_clear(g);
    return R;
}

static Polyhedron *reduce_domain(Polyhedron *D, Matrix *CT, Polyhedron *CEq,
                                 Polyhedron **fVD, int nd, unsigned MaxRays)
{
    assert(CEq);

    Polyhedron *Dt;
    Dt = CT ? DomainPreimage(D, CT, MaxRays) : D;
    Polyhedron *rVD = DomainIntersection(Dt, CEq, MaxRays);

    /* if rVD is empty or too small in geometric dimension */
    if(!rVD || emptyQ(rVD) ||
            (rVD->Dimension-rVD->NbEq < Dt->Dimension-Dt->NbEq-CEq->NbEq)) {
        if(rVD)
            Domain_Free(rVD);
        if (CT)
            Domain_Free(Dt);
        return 0;               /* empty validity domain */
    }

    if (CT)
        Domain_Free(Dt);

    fVD[nd] = Domain_Copy(rVD);
    for (int i = 0 ; i < nd; ++i) {
        Polyhedron *I = DomainIntersection(fVD[nd], fVD[i], MaxRays);
        if (emptyQ(I)) {
            Domain_Free(I);
            continue;
        }
        Polyhedron *F = DomainSimplify(I, fVD[nd], MaxRays);
        if (F->NbEq == 1) {
            Polyhedron *T = rVD;
            rVD = DomainDifference(rVD, F, MaxRays);
            Domain_Free(T);
        }
        Domain_Free(F);
        Domain_Free(I);
    }

    rVD = DomainConstraintSimplify(rVD, MaxRays);
    if (emptyQ(rVD)) {
        Domain_Free(fVD[nd]);
        Domain_Free(rVD);
        return 0;
    }

    Value c;
    value_init(c);
    barvinok_count(rVD, &c, MaxRays);
    if (value_zero_p(c)) {
        Domain_Free(rVD);
        rVD = 0;
    }
    value_clear(c);

    return rVD;
}

evalue* barvinok_enumerate_ev(Polyhedron *P, Polyhedron* C, unsigned MaxRays)
{
    //P = unfringe(P, MaxRays);
    Polyhedron *CEq = NULL, *rVD, *pVD, *CA;
    Matrix *CT = NULL;
    Param_Polyhedron *PP = NULL;
    Param_Domain *D, *next;
    Param_Vertices *V;
    int r = 0;
    unsigned nparam = C->Dimension;
    evalue *eres;
    ALLOC(evalue, eres);
    value_init(eres->d);
    value_set_si(eres->d, 0);

    evalue factor;
    value_init(factor.d);
    evalue_set_si(&factor, 1, 1);
    
    CA = align_context(C, P->Dimension, MaxRays);
    P = DomainIntersection(P, CA, MaxRays);
    Polyhedron_Free(CA);

    if (C->Dimension == 0 || emptyQ(P)) {
constant:
        eres->x.p = new_enode(partition, 2, C->Dimension);
        EVALUE_SET_DOMAIN(eres->x.p->arr[0], 
            DomainConstraintSimplify(CEq ? CEq : Polyhedron_Copy(C), MaxRays));
        value_set_si(eres->x.p->arr[1].d, 1);
        value_init(eres->x.p->arr[1].x.n);
        if (emptyQ(P))
            value_set_si(eres->x.p->arr[1].x.n, 0);
        else
            barvinok_count(P, &eres->x.p->arr[1].x.n, MaxRays);
out:
        emul(&factor, eres);
        reduce_evalue(eres);
        free_evalue_refs(&factor);
        Polyhedron_Free(P);
        if (CT)
            Matrix_Free(CT);
        if (PP)
            Param_Polyhedron_Free(PP);
           
        return eres;
    }
    for (r = 0; r < P->NbRays; ++r)
        if (value_zero_p(P->Ray[r][0]) ||
                value_zero_p(P->Ray[r][P->Dimension+1])) {
            int i;
            for (i = P->Dimension - nparam; i < P->Dimension; ++i)
                if (value_notzero_p(P->Ray[r][i+1]))
                    break;
            if (i >= P->Dimension)
                break;
        }
    if (r <  P->NbRays)
        goto constant;

    if (P->NbEq != 0) {
        Matrix *f;
        P = remove_equalities_p(P, P->Dimension-nparam, &f);
        mask(f, &factor);
        Matrix_Free(f);
    }
    if (P->Dimension == nparam) {
        CEq = P;
        P = Universe_Polyhedron(0);
        goto constant;
    }

    Polyhedron *Q = ParamPolyhedron_Reduce(P, P->Dimension-nparam, &factor);
    if (Q) {
        Polyhedron_Free(P);
        if (Q->Dimension == nparam) {
            CEq = Q;
            P = Universe_Polyhedron(0);
            goto constant;
        }
        P = Q;
    }
    Polyhedron *oldP = P;
    PP = Polyhedron2Param_SimplifiedDomain(&P,C,MaxRays,&CEq,&CT);
    if (P != oldP)
        Polyhedron_Free(oldP);

    if (isIdentity(CT)) {
        Matrix_Free(CT);
        CT = NULL;
    } else {
        assert(CT->NbRows != CT->NbColumns);
        if (CT->NbRows == 1)            // no more parameters
            goto constant;
        nparam = CT->NbRows - 1;
    }

    unsigned dim = P->Dimension - nparam;
    Polyhedron ** vcone = new Polyhedron_p[PP->nbV];
    int * npos = new int[PP->nbV];
    int * nneg = new int[PP->nbV];
    vec_ZZ sign;

    int i;
    for (i = 0, V = PP->V; V; ++i, V = V->next) {
        Polyhedron *C = supporting_cone_p(P, V);
        decompose(C, &vcone[i], &npos[i], &nneg[i], MaxRays);
    }

    Vector *c = Vector_Alloc(dim+2);

    int nd;
    for (nd = 0, D=PP->D; D; ++nd, D=D->next);
    struct section { Polyhedron *D; evalue E; };
    section *s = new section[nd];
    Polyhedron **fVD = new Polyhedron_p[nd];

    for(nd = 0, D=PP->D; D; D=next) {
        next = D->next;

        Polyhedron *rVD = reduce_domain(D->Domain, CT, CEq,
                                        fVD, nd, MaxRays);
        if (!rVD)
            continue;

        pVD = CT ? DomainImage(rVD,CT,MaxRays) : rVD;

        int ncone = 0;
        sign.SetLength(ncone);
        FORALL_PVertex_in_ParamPolyhedron(V,D,PP) // _i is internal counter
            ncone += npos[_i] + nneg[_i];
            sign.SetLength(ncone);
            for (int k = 0; k < npos[_i]; ++k)
                sign[ncone-nneg[_i]-k-1] = 1;
            for (int k = 0; k < nneg[_i]; ++k)
                sign[ncone-k-1] = -1;
        END_FORALL_PVertex_in_ParamPolyhedron;

        mat_ZZ rays;
        rays.SetDims(ncone * dim, dim);
        r = 0;
        FORALL_PVertex_in_ParamPolyhedron(V,D,PP) // _i is internal counter
            for (Polyhedron *i = vcone[_i]; i; i = i->next) {
                assert(i->NbRays-1 == dim);
                add_rays(rays, i, &r);
            }
        END_FORALL_PVertex_in_ParamPolyhedron;
        vec_ZZ lambda;
        nonorthog(rays, lambda);

        mat_ZZ den;
        den.SetDims(ncone,dim);
        term_info *num = new term_info[ncone];
          
        int f = 0;
        FORALL_PVertex_in_ParamPolyhedron(V,D,PP)
            for (Polyhedron *i = vcone[_i]; i; i = i->next) {
                lattice_point(V, i, lambda, &num[f], pVD);
                normalize(i, lambda, sign[f], num[f].constant, den[f]);
                ++f;
            }
        END_FORALL_PVertex_in_ParamPolyhedron;
        ZZ min = num[0].constant;
        for (int j = 1; j < ncone; ++j)
            if (num[j].constant < min)
                min = num[j].constant;
        for (int j = 0; j < ncone; ++j)
            num[j].constant -= min;
        f = 0;
        value_init(s[nd].E.d);
        evalue_set_si(&s[nd].E, 0, 1);
        mpq_t count;
        mpq_init(count);
        FORALL_PVertex_in_ParamPolyhedron(V,D,PP)
            for (Polyhedron *i = vcone[_i]; i; i = i->next) {
                dpoly n(dim, den[f][0], 1);
                for (int k = 1; k < dim; ++k) {
                    dpoly fact(dim, den[f][k], 1);
                    n *= fact;
                }
                if (num[f].E != NULL) {
                    ZZ one(INIT_VAL, 1);
                    dpoly_n d(dim, num[f].constant, one);
                    d.div(n, c, sign[f]);
                    evalue EV; 
                    multi_polynom(c, num[f].E, &EV);
                    eadd(&EV , &s[nd].E);
                    free_evalue_refs(&EV);
                    free_evalue_refs(num[f].E);
                    delete num[f].E; 
                } else if (num[f].pos != -1) {
                    dpoly_n d(dim, num[f].constant, num[f].coeff);
                    d.div(n, c, sign[f]);
                    evalue EV;
                    uni_polynom(num[f].pos, c, &EV);
                    eadd(&EV , &s[nd].E);
                    free_evalue_refs(&EV);
                } else {
                    mpq_set_si(count, 0, 1);
                    dpoly d(dim, num[f].constant);
                    d.div(n, count, sign[f]);
                    evalue EV;
                    value_init(EV.d);
                    evalue_set(&EV, &count[0]._mp_num, &count[0]._mp_den);
                    eadd(&EV , &s[nd].E);
                    free_evalue_refs(&EV);
                } 
                ++f;
            }
        END_FORALL_PVertex_in_ParamPolyhedron;

        mpq_clear(count);
        delete [] num;

        if (CT)
            addeliminatedparams_evalue(&s[nd].E, CT);
        s[nd].D = rVD;
        ++nd;
        if (rVD != pVD)
            Domain_Free(pVD);
    }

    if (nd == 0)
        evalue_set_si(eres, 0, 1);
    else {
        eres->x.p = new_enode(partition, 2*nd, C->Dimension);
        for (int j = 0; j < nd; ++j) {
            EVALUE_SET_DOMAIN(eres->x.p->arr[2*j], s[j].D);
            value_clear(eres->x.p->arr[2*j+1].d);
            eres->x.p->arr[2*j+1] = s[j].E;
            Domain_Free(fVD[j]);
        }
    }
    delete [] s;
    delete [] fVD;

    Vector_Free(c);

    for (int j = 0; j < PP->nbV; ++j)
        Domain_Free(vcone[j]);
    delete [] vcone;
    delete [] npos;
    delete [] nneg;

    if (CEq)
        Polyhedron_Free(CEq);

    goto out;
}

Enumeration* barvinok_enumerate(Polyhedron *P, Polyhedron* C, unsigned MaxRays)
{
    evalue *EP = barvinok_enumerate_ev(P, C, MaxRays);

    return partition2enumeration(EP);
}

static void SwapColumns(Value **V, int n, int i, int j)
{
    for (int r = 0; r < n; ++r)
        value_swap(V[r][i], V[r][j]);
}

static void SwapColumns(Polyhedron *P, int i, int j)
{
    SwapColumns(P->Constraint, P->NbConstraints, i, j);
    SwapColumns(P->Ray, P->NbRays, i, j);
}

static void negative_test_constraint(Value *l, Value *u, Value *c, int pos,
                                     int len, Value *v)
{
    value_oppose(*v, u[pos+1]);
    Vector_Combine(l+1, u+1, c+1, *v, l[pos+1], len-1);
    value_multiply(*v, *v, l[pos+1]);
    value_substract(c[len-1], c[len-1], *v);
    value_set_si(*v, -1);
    Vector_Scale(c+1, c+1, *v, len-1);
    value_decrement(c[len-1], c[len-1]);
    ConstraintSimplify(c, c, len, v);
}

static void oppose_constraint(Value *c, int len, Value *v)
{
    value_set_si(*v, -1);
    Vector_Scale(c+1, c+1, *v, len-1);
    value_decrement(c[len-1], c[len-1]);
}

static bool SplitOnConstraint(Polyhedron *P, int i, int l, int u,
                              int nvar, int len, int exist, int MaxRays,
                              Vector *row, Value& f, bool independent,
                              Polyhedron **pos, Polyhedron **neg)
{
    negative_test_constraint(P->Constraint[l], P->Constraint[u],
                             row->p, nvar+i, len, &f);
    *neg = AddConstraints(row->p, 1, P, MaxRays);

    /* We found an independent, but useless constraint
     * Maybe we should detect this earlier and not
     * mark the variable as INDEPENDENT
     */
    if (emptyQ((*neg))) {
        Polyhedron_Free(*neg);
        return false;
    }

    oppose_constraint(row->p, len, &f);
    *pos = AddConstraints(row->p, 1, P, MaxRays);

    if (emptyQ((*pos))) {
        Polyhedron_Free(*neg);
        Polyhedron_Free(*pos);
        return false;
    }

    return true;
}

/*
 * unimodularly transform P such that constraint r is transformed
 * into a constraint that involves only a single (the first)
 * existential variable
 *
 */
static Polyhedron *rotate_along(Polyhedron *P, int r, int nvar, int exist,
                                unsigned MaxRays)
{
    Value g;
    value_init(g);

    Vector *row = Vector_Alloc(exist);
    Vector_Copy(P->Constraint[r]+1+nvar, row->p, exist);
    Vector_Gcd(row->p, exist, &g);
    if (value_notone_p(g))
        Vector_AntiScale(row->p, row->p, g, exist);
    value_clear(g);

    Matrix *M = unimodular_complete(row);
    Matrix *M2 = Matrix_Alloc(P->Dimension+1, P->Dimension+1);
    for (r = 0; r < nvar; ++r)
        value_set_si(M2->p[r][r], 1);
    for ( ; r < nvar+exist; ++r)
        Vector_Copy(M->p[r-nvar], M2->p[r]+nvar, exist);
    for ( ; r < P->Dimension+1; ++r)
        value_set_si(M2->p[r][r], 1);
    Polyhedron *T = Polyhedron_Image(P, M2, MaxRays);

    Matrix_Free(M2);
    Matrix_Free(M);
    Vector_Free(row);

    return T;
}

static bool SplitOnVar(Polyhedron *P, int i, 
                              int nvar, int len, int exist, int MaxRays,
                              Vector *row, Value& f, bool independent,
                              Polyhedron **pos, Polyhedron **neg)
{
    int j;

    for (int l = P->NbEq; l < P->NbConstraints; ++l) {
        if (value_negz_p(P->Constraint[l][nvar+i+1]))
            continue;

        if (independent) {
            for (j = 0; j < exist; ++j)
                if (j != i && value_notzero_p(P->Constraint[l][nvar+j+1]))
                    break;
            if (j < exist)
                continue;
        }

        for (int u = P->NbEq; u < P->NbConstraints; ++u) {
            if (value_posz_p(P->Constraint[u][nvar+i+1]))
                continue;

            if (independent) {
                for (j = 0; j < exist; ++j)
                    if (j != i && value_notzero_p(P->Constraint[u][nvar+j+1]))
                        break;
                if (j < exist)
                    continue;
            }

            if (SplitOnConstraint(P, i, l, u, 
                                   nvar, len, exist, MaxRays,
                                   row, f, independent,
                                   pos, neg)) {
                if (independent) {
                    if (i != 0)
                        SwapColumns(*neg, nvar+1, nvar+1+i);
                }
                return true;
            }
        }
    }

    return false;
}

static bool double_bound_pair(Polyhedron *P, int nvar, int exist,
                         int i, int l1, int l2,
                         Polyhedron **pos, Polyhedron **neg)
{
    Value f;
    value_init(f);
    Vector *row = Vector_Alloc(P->Dimension+2);
    value_set_si(row->p[0], 1);
    value_oppose(f, P->Constraint[l1][nvar+i+1]);
    Vector_Combine(P->Constraint[l1]+1, P->Constraint[l2]+1,
                   row->p+1,
                   P->Constraint[l2][nvar+i+1], f,
                   P->Dimension+1);
    ConstraintSimplify(row->p, row->p, P->Dimension+2, &f);
    *pos = AddConstraints(row->p, 1, P, 0);
    value_set_si(f, -1);
    Vector_Scale(row->p+1, row->p+1, f, P->Dimension+1);
    value_decrement(row->p[P->Dimension+1], row->p[P->Dimension+1]);
    *neg = AddConstraints(row->p, 1, P, 0);
    Vector_Free(row);
    value_clear(f);

    return !emptyQ((*pos)) && !emptyQ((*neg));
}

static bool double_bound(Polyhedron *P, int nvar, int exist,
                         Polyhedron **pos, Polyhedron **neg)
{
    for (int i = 0; i < exist; ++i) {
        int l1, l2;
        for (l1 = P->NbEq; l1 < P->NbConstraints; ++l1) {
            if (value_negz_p(P->Constraint[l1][nvar+i+1]))
                continue;
            for (l2 = l1 + 1; l2 < P->NbConstraints; ++l2) {
                if (value_negz_p(P->Constraint[l2][nvar+i+1]))
                    continue;
                if (double_bound_pair(P, nvar, exist, i, l1, l2, pos, neg))
                    return true;
            }
        }
        for (l1 = P->NbEq; l1 < P->NbConstraints; ++l1) {
            if (value_posz_p(P->Constraint[l1][nvar+i+1]))
                continue;
            if (l1 < P->NbConstraints)
                for (l2 = l1 + 1; l2 < P->NbConstraints; ++l2) {
                    if (value_posz_p(P->Constraint[l2][nvar+i+1]))
                        continue;
                if (double_bound_pair(P, nvar, exist, i, l1, l2, pos, neg))
                    return true;
            }
        }
        return false;
    }
    return false;
}

enum constraint { 
ALL_POS = 1 << 0,
ONE_NEG = 1 << 1,
INDEPENDENT = 1 << 2
};

static evalue* enumerate_or(Polyhedron *D,
                          unsigned exist, unsigned nparam, unsigned MaxRays)
{
#ifdef DEBUG_ER
    fprintf(stderr, "\nER: Or\n");
#endif /* DEBUG_ER */

    Polyhedron *N = D->next;
    D->next = 0;
    evalue *EP = 
        barvinok_enumerate_e(D, exist, nparam, MaxRays);
    Polyhedron_Free(D);

    for (D = N; D; D = N) {
        N = D->next;
        D->next = 0;

        evalue *EN = 
            barvinok_enumerate_e(D, exist, nparam, MaxRays);

        eor(EN, EP);
        free_evalue_refs(EN); 
        free(EN);
        Polyhedron_Free(D);
    }

    reduce_evalue(EP);

    return EP;
}

static evalue* enumerate_sum(Polyhedron *P,
                          unsigned exist, unsigned nparam, unsigned MaxRays)
{
    int nvar = P->Dimension - exist - nparam;
    int toswap = nvar < exist ? nvar : exist;
    for (int i = 0; i < toswap; ++i)
        SwapColumns(P, 1 + i, nvar+exist - i);
    nparam += nvar;

#ifdef DEBUG_ER
    fprintf(stderr, "\nER: Sum\n");
#endif /* DEBUG_ER */

    evalue *EP = barvinok_enumerate_e(P, exist, nparam, MaxRays);

    for (int i = 0; i < /* nvar */ nparam; ++i) {
        Matrix *C = Matrix_Alloc(1, 1 + nparam + 1);
        value_set_si(C->p[0][0], 1);
        evalue split;
        value_init(split.d);
        value_set_si(split.d, 0);
        split.x.p = new_enode(partition, 4, nparam);
        value_set_si(C->p[0][1+i], 1);
        Matrix *C2 = Matrix_Copy(C);
        EVALUE_SET_DOMAIN(split.x.p->arr[0],
            Constraints2Polyhedron(C2, MaxRays));
        Matrix_Free(C2);
        evalue_set_si(&split.x.p->arr[1], 1, 1);
        value_set_si(C->p[0][1+i], -1);
        value_set_si(C->p[0][1+nparam], -1);
        EVALUE_SET_DOMAIN(split.x.p->arr[2],
            Constraints2Polyhedron(C, MaxRays));
        evalue_set_si(&split.x.p->arr[3], 1, 1);
        emul(&split, EP);
        free_evalue_refs(&split);
        Matrix_Free(C);
    }
    reduce_evalue(EP);
    evalue_range_reduction(EP);

    evalue_frac2floor(EP);

    evalue *sum = esum(EP, nvar);

    free_evalue_refs(EP); 
    free(EP);
    EP = sum;

    evalue_range_reduction(EP);

    return EP;
}

static evalue* split_sure(Polyhedron *P, Polyhedron *S,
                          unsigned exist, unsigned nparam, unsigned MaxRays)
{
    int nvar = P->Dimension - exist - nparam;

    Matrix *M = Matrix_Alloc(exist, S->Dimension+2);
    for (int i = 0; i < exist; ++i)
        value_set_si(M->p[i][nvar+i+1], 1);
    Polyhedron *O = S;
    S = DomainAddRays(S, M, MaxRays);
    Polyhedron_Free(O);
    Polyhedron *F = DomainAddRays(P, M, MaxRays);
    Polyhedron *D = DomainDifference(F, S, MaxRays);
    O = D;
    D = Disjoint_Domain(D, 0, MaxRays);
    Polyhedron_Free(F);
    Domain_Free(O);
    Matrix_Free(M);

    M = Matrix_Alloc(P->Dimension+1-exist, P->Dimension+1);
    for (int j = 0; j < nvar; ++j)
        value_set_si(M->p[j][j], 1);
    for (int j = 0; j < nparam+1; ++j)
        value_set_si(M->p[nvar+j][nvar+exist+j], 1);
    Polyhedron *T = Polyhedron_Image(S, M, MaxRays);
    evalue *EP = barvinok_enumerate_e(T, 0, nparam, MaxRays);
    Polyhedron_Free(S);
    Polyhedron_Free(T);
    Matrix_Free(M);

    for (Polyhedron *Q = D; Q; Q = Q->next) {
        Polyhedron *N = Q->next;
        Q->next = 0;
        T = DomainIntersection(P, Q, MaxRays);
        evalue *E = barvinok_enumerate_e(T, exist, nparam, MaxRays);
        eadd(E, EP);
        free_evalue_refs(E); 
        free(E);
        Polyhedron_Free(T);
        Q->next = N;
    }
    Domain_Free(D);
    return EP;
}

static evalue* enumerate_sure(Polyhedron *P,
                          unsigned exist, unsigned nparam, unsigned MaxRays)
{
    int i;
    Polyhedron *S = P;
    int nvar = P->Dimension - exist - nparam;
    Value lcm;
    Value f;
    value_init(lcm);
    value_init(f);

    for (i = 0; i < exist; ++i) {
        Matrix *M = Matrix_Alloc(S->NbConstraints, S->Dimension+2);
        int c = 0;
        value_set_si(lcm, 1);
        for (int j = 0; j < S->NbConstraints; ++j) {
            if (value_negz_p(S->Constraint[j][1+nvar+i]))
                continue;
            if (value_one_p(S->Constraint[j][1+nvar+i]))
                continue;
            value_lcm(lcm, S->Constraint[j][1+nvar+i], &lcm);
        }

        for (int j = 0; j < S->NbConstraints; ++j) {
            if (value_negz_p(S->Constraint[j][1+nvar+i]))
                continue;
            if (value_one_p(S->Constraint[j][1+nvar+i]))
                continue;
            value_division(f, lcm, S->Constraint[j][1+nvar+i]);
            Vector_Scale(S->Constraint[j], M->p[c], f, S->Dimension+2);
            value_substract(M->p[c][S->Dimension+1], 
                            M->p[c][S->Dimension+1],
                            lcm);
            value_increment(M->p[c][S->Dimension+1], 
                            M->p[c][S->Dimension+1]);
            ++c;
        }
        Polyhedron *O = S;
        S = AddConstraints(M->p[0], c, S, MaxRays);
        if (O != P)
            Polyhedron_Free(O);
        Matrix_Free(M);
        if (emptyQ(S)) {
            Polyhedron_Free(S);
            value_clear(lcm);
            value_clear(f);
            return 0;
        }
    }
    value_clear(lcm);
    value_clear(f);

#ifdef DEBUG_ER
    fprintf(stderr, "\nER: Sure\n");
#endif /* DEBUG_ER */

    return split_sure(P, S, exist, nparam, MaxRays);
}

static evalue* enumerate_sure2(Polyhedron *P,
                          unsigned exist, unsigned nparam, unsigned MaxRays)
{
    int nvar = P->Dimension - exist - nparam;
    int r;
    for (r = 0; r < P->NbRays; ++r)
        if (value_one_p(P->Ray[r][0]) &&
                value_one_p(P->Ray[r][P->Dimension+1]))
            break;

    if (r >= P->NbRays)
        return 0;

    Matrix *M = Matrix_Alloc(nvar + 1 + nparam, P->Dimension+2);
    for (int i = 0; i < nvar; ++i)
        value_set_si(M->p[i][1+i], 1);
    for (int i = 0; i < nparam; ++i)
        value_set_si(M->p[i+nvar][1+nvar+exist+i], 1);
    Vector_Copy(P->Ray[r]+1+nvar, M->p[nvar+nparam]+1+nvar, exist);
    value_set_si(M->p[nvar+nparam][0], 1);
    value_set_si(M->p[nvar+nparam][P->Dimension+1], 1);
    Polyhedron * F = Rays2Polyhedron(M, MaxRays);
    Matrix_Free(M);

    Polyhedron *I = DomainIntersection(F, P, MaxRays);
    Polyhedron_Free(F);

#ifdef DEBUG_ER
    fprintf(stderr, "\nER: Sure2\n");
#endif /* DEBUG_ER */

    return split_sure(P, I, exist, nparam, MaxRays);
}

static evalue* enumerate_cyclic(Polyhedron *P,
                          unsigned exist, unsigned nparam, 
                          evalue * EP, int r, int p, unsigned MaxRays)
{
    int nvar = P->Dimension - exist - nparam;

    /* If EP in its fractional maps only contains references
     * to the remainder parameter with appropriate coefficients
     * then we could in principle avoid adding existentially
     * quantified variables to the validity domains.
     * We'd have to replace the remainder by m { p/m }
     * and multiply with an appropriate factor that is one
     * only in the appropriate range.
     * This last multiplication can be avoided if EP
     * has a single validity domain with no (further)
     * constraints on the remainder parameter
     */

    Matrix *CT = Matrix_Alloc(nparam+1, nparam+3);
    Matrix *M = Matrix_Alloc(1, 1+nparam+3);
    for (int j = 0; j < nparam; ++j)
        if (j != p)
            value_set_si(CT->p[j][j], 1);
    value_set_si(CT->p[p][nparam+1], 1);
    value_set_si(CT->p[nparam][nparam+2], 1);
    value_set_si(M->p[0][1+p], -1);
    value_absolute(M->p[0][1+nparam], P->Ray[0][1+nvar+exist+p]);
    value_set_si(M->p[0][1+nparam+1], 1);
    Polyhedron *CEq = Constraints2Polyhedron(M, 1);
    Matrix_Free(M);
    addeliminatedparams_enum(EP, CT, CEq, MaxRays, nparam);
    Polyhedron_Free(CEq);
    Matrix_Free(CT);

    return EP;
}

static void enumerate_vd_add_ray(evalue *EP, Matrix *Rays, unsigned MaxRays)
{
    if (value_notzero_p(EP->d))
        return;

    assert(EP->x.p->type == partition);
    assert(EP->x.p->pos == EVALUE_DOMAIN(EP->x.p->arr[0])->Dimension);
    for (int i = 0; i < EP->x.p->size/2; ++i) {
        Polyhedron *D = EVALUE_DOMAIN(EP->x.p->arr[2*i]);
        Polyhedron *N = DomainAddRays(D, Rays, MaxRays);
        EVALUE_SET_DOMAIN(EP->x.p->arr[2*i], N);
        Domain_Free(D);
    }
}

static evalue* enumerate_line(Polyhedron *P,
                          unsigned exist, unsigned nparam, unsigned MaxRays)
{
    if (P->NbBid == 0)
        return 0;

#ifdef DEBUG_ER
    fprintf(stderr, "\nER: Line\n");
#endif /* DEBUG_ER */

    int nvar = P->Dimension - exist - nparam;
    int i, j;
    for (i = 0; i < nparam; ++i)
        if (value_notzero_p(P->Ray[0][1+nvar+exist+i]))
            break;
    assert(i < nparam);
    for (j = i+1; j < nparam; ++j)
        if (value_notzero_p(P->Ray[0][1+nvar+exist+i]))
            break;
    assert(j >= nparam); // for now

    Matrix *M = Matrix_Alloc(2, P->Dimension+2);
    value_set_si(M->p[0][0], 1);
    value_set_si(M->p[0][1+nvar+exist+i], 1);
    value_set_si(M->p[1][0], 1);
    value_set_si(M->p[1][1+nvar+exist+i], -1);
    value_absolute(M->p[1][1+P->Dimension], P->Ray[0][1+nvar+exist+i]);
    value_decrement(M->p[1][1+P->Dimension], M->p[1][1+P->Dimension]);
    Polyhedron *S = AddConstraints(M->p[0], 2, P, MaxRays);
    evalue *EP = barvinok_enumerate_e(S, exist, nparam, MaxRays);
    Polyhedron_Free(S);
    Matrix_Free(M);

    return enumerate_cyclic(P, exist, nparam, EP, 0, i, MaxRays);
}

static int single_param_pos(Polyhedron*P, unsigned exist, unsigned nparam, 
                            int r)
{
    int nvar = P->Dimension - exist - nparam;
    if (First_Non_Zero(P->Ray[r]+1, nvar) != -1)
        return -1;
    int i = First_Non_Zero(P->Ray[r]+1+nvar+exist, nparam);
    if (i == -1)
        return -1;
    if (First_Non_Zero(P->Ray[r]+1+nvar+exist+1, nparam-i-1) != -1)
        return -1;
    return i;
}

static evalue* enumerate_remove_ray(Polyhedron *P, int r,
                          unsigned exist, unsigned nparam, unsigned MaxRays)
{
#ifdef DEBUG_ER
    fprintf(stderr, "\nER: RedundantRay\n");
#endif /* DEBUG_ER */

    Value one;
    value_init(one);
    value_set_si(one, 1);
    int len = P->NbRays-1;
    Matrix *M = Matrix_Alloc(2 * len, P->Dimension+2);
    Vector_Copy(P->Ray[0], M->p[0], r * (P->Dimension+2));
    Vector_Copy(P->Ray[r+1], M->p[r], (len-r) * (P->Dimension+2));
    for (int j = 0; j < P->NbRays; ++j) {
        if (j == r)
            continue;
        Vector_Combine(P->Ray[j], P->Ray[r], M->p[len+j-(j>r)], 
                       one, P->Ray[j][P->Dimension+1], P->Dimension+2);
    }

    P = Rays2Polyhedron(M, MaxRays);
    Matrix_Free(M);
    evalue *EP = barvinok_enumerate_e(P, exist, nparam, MaxRays);
    Polyhedron_Free(P);
    value_clear(one);

    return EP;
}

static evalue* enumerate_redundant_ray(Polyhedron *P,
                          unsigned exist, unsigned nparam, unsigned MaxRays)
{
    assert(P->NbBid == 0);
    int nvar = P->Dimension - exist - nparam;
    Value m;
    value_init(m);

    for (int r = 0; r < P->NbRays; ++r) {
        if (value_notzero_p(P->Ray[r][P->Dimension+1]))
            continue;
        int i1 = single_param_pos(P, exist, nparam, r);
        if (i1 == -1)
            continue;
        for (int r2 = r+1; r2 < P->NbRays; ++r2) {
            if (value_notzero_p(P->Ray[r2][P->Dimension+1]))
                continue;
            int i2 = single_param_pos(P, exist, nparam, r2);
            if (i2 == -1)
                continue;
            if (i1 != i2)
                continue;

            value_division(m, P->Ray[r][1+nvar+exist+i1], 
                              P->Ray[r2][1+nvar+exist+i1]);
            value_multiply(m, m, P->Ray[r2][1+nvar+exist+i1]);
            /* r2 divides r => r redundant */
            if (value_eq(m, P->Ray[r][1+nvar+exist+i1])) {
                value_clear(m);
                return enumerate_remove_ray(P, r, exist, nparam, MaxRays);
            }

            value_division(m, P->Ray[r2][1+nvar+exist+i1], 
                              P->Ray[r][1+nvar+exist+i1]);
            value_multiply(m, m, P->Ray[r][1+nvar+exist+i1]);
            /* r divides r2 => r2 redundant */
            if (value_eq(m, P->Ray[r2][1+nvar+exist+i1])) {
                value_clear(m);
                return enumerate_remove_ray(P, r2, exist, nparam, MaxRays);
            }
        }
    }
    value_clear(m);
    return 0;
}

static Polyhedron *upper_bound(Polyhedron *P, 
                               int pos, Value *max, Polyhedron **R)
{
    Value v;
    int r;
    value_init(v);

    *R = 0;
    Polyhedron *N;
    Polyhedron *B = 0;
    for (Polyhedron *Q = P; Q; Q = N) {
        N = Q->next;
        for (r = 0; r < P->NbRays; ++r) {
            if (value_zero_p(P->Ray[r][P->Dimension+1]) &&
                    value_pos_p(P->Ray[r][1+pos]))
                break;
        }
        if (r < P->NbRays) {
            Q->next = *R;
            *R = Q;
            continue;
        } else {
            Q->next = B;
            B = Q;
        }
        for (r = 0; r < P->NbRays; ++r) {
            if (value_zero_p(P->Ray[r][P->Dimension+1]))
                continue;
            mpz_fdiv_q(v, P->Ray[r][1+pos], P->Ray[r][1+P->Dimension]);
            if ((!Q->next && r == 0) || value_gt(v, *max))
                value_assign(*max, v);
        }
    }
    value_clear(v);
    return B;
}

static evalue* enumerate_ray(Polyhedron *P,
                          unsigned exist, unsigned nparam, unsigned MaxRays)
{
    assert(P->NbBid == 0);
    int nvar = P->Dimension - exist - nparam;

    int r;
    for (r = 0; r < P->NbRays; ++r)
        if (value_zero_p(P->Ray[r][P->Dimension+1]))
            break;
    if (r >= P->NbRays)
        return 0;

    int r2;
    for (r2 = r+1; r2 < P->NbRays; ++r2)
        if (value_zero_p(P->Ray[r2][P->Dimension+1]))
            break;
    if (r2 < P->NbRays) {
        if (nvar > 0)
            return enumerate_sum(P, exist, nparam, MaxRays);
    }

#ifdef DEBUG_ER
    fprintf(stderr, "\nER: Ray\n");
#endif /* DEBUG_ER */

    Value m;
    Value one;
    value_init(m);
    value_init(one);
    value_set_si(one, 1);
    int i = single_param_pos(P, exist, nparam, r);
    assert(i != -1); // for now;

    Matrix *M = Matrix_Alloc(P->NbRays, P->Dimension+2);
    for (int j = 0; j < P->NbRays; ++j) {
        Vector_Combine(P->Ray[j], P->Ray[r], M->p[j], 
                       one, P->Ray[j][P->Dimension+1], P->Dimension+2);
    }
    Polyhedron *S = Rays2Polyhedron(M, MaxRays);
    Matrix_Free(M);
    Polyhedron *D = DomainDifference(P, S, MaxRays);
    Polyhedron_Free(S);
    // Polyhedron_Print(stderr, P_VALUE_FMT, D);
    assert(value_pos_p(P->Ray[r][1+nvar+exist+i])); // for now
    Polyhedron *R;
    D = upper_bound(D, nvar+exist+i, &m, &R);
    assert(D);
    Domain_Free(D);

    M = Matrix_Alloc(2, P->Dimension+2);
    value_set_si(M->p[0][0], 1);
    value_set_si(M->p[1][0], 1);
    value_set_si(M->p[0][1+nvar+exist+i], -1);
    value_set_si(M->p[1][1+nvar+exist+i], 1);
    value_assign(M->p[0][1+P->Dimension], m);
    value_oppose(M->p[1][1+P->Dimension], m);
    value_addto(M->p[1][1+P->Dimension], M->p[1][1+P->Dimension], 
                P->Ray[r][1+nvar+exist+i]);
    value_decrement(M->p[1][1+P->Dimension], M->p[1][1+P->Dimension]);
    // Matrix_Print(stderr, P_VALUE_FMT, M);
    D = AddConstraints(M->p[0], 2, P, MaxRays);
    // Polyhedron_Print(stderr, P_VALUE_FMT, D);
    value_substract(M->p[0][1+P->Dimension], M->p[0][1+P->Dimension], 
                    P->Ray[r][1+nvar+exist+i]);
    // Matrix_Print(stderr, P_VALUE_FMT, M);
    S = AddConstraints(M->p[0], 1, P, MaxRays);
    // Polyhedron_Print(stderr, P_VALUE_FMT, S);
    Matrix_Free(M);

    evalue *EP = barvinok_enumerate_e(D, exist, nparam, MaxRays);
    Polyhedron_Free(D);
    value_clear(one);
    value_clear(m);

    if (value_notone_p(P->Ray[r][1+nvar+exist+i]))
        EP = enumerate_cyclic(P, exist, nparam, EP, r, i, MaxRays);
    else {
        M = Matrix_Alloc(1, nparam+2);
        value_set_si(M->p[0][0], 1);
        value_set_si(M->p[0][1+i], 1);
        enumerate_vd_add_ray(EP, M, MaxRays);
        Matrix_Free(M);
    }

    if (!emptyQ(S)) {
        evalue *E = barvinok_enumerate_e(S, exist, nparam, MaxRays);
        eadd(E, EP);
        free_evalue_refs(E);
        free(E);
    }
    Polyhedron_Free(S);

    if (R) {
        assert(nvar == 0);
        evalue *ER = enumerate_or(R, exist, nparam, MaxRays);
        eor(ER, EP);
        free_evalue_refs(ER);
        free(ER);
    }

    return EP;
}

static evalue* new_zero_ep()
{
    evalue *EP;
    ALLOC(evalue, EP);
    value_init(EP->d);
    evalue_set_si(EP, 0, 1);
    return EP;
}

static evalue* enumerate_vd(Polyhedron **PA,
                          unsigned exist, unsigned nparam, unsigned MaxRays)
{
    Polyhedron *P = *PA;
    int nvar = P->Dimension - exist - nparam;
    Param_Polyhedron *PP = NULL;
    Polyhedron *C = Universe_Polyhedron(nparam);
    Polyhedron *CEq;
    Matrix *CT;
    Polyhedron *PR = P;
    PP = Polyhedron2Param_SimplifiedDomain(&PR,C,MaxRays,&CEq,&CT);
    Polyhedron_Free(C);

    int nd;
    Param_Domain *D, *last;
    Value c;
    value_init(c);
    for (nd = 0, D=PP->D; D; D=D->next, ++nd)
        ;

    Polyhedron **VD = new Polyhedron_p[nd];
    Polyhedron **fVD = new Polyhedron_p[nd];
    for(nd = 0, D=PP->D; D; D=D->next) {
        Polyhedron *rVD = reduce_domain(D->Domain, CT, CEq,
                                        fVD, nd, MaxRays);
        if (!rVD)
            continue;

        VD[nd++] = rVD;
        last = D;
    }

    evalue *EP = 0;

    if (nd == 0)
        EP = new_zero_ep();

    /* This doesn't seem to have any effect */
    if (nd == 1) {
        Polyhedron *CA = align_context(VD[0], P->Dimension, MaxRays);
        Polyhedron *O = P;
        P = DomainIntersection(P, CA, MaxRays);
        if (O != *PA)
            Polyhedron_Free(O);
        Polyhedron_Free(CA);
        if (emptyQ(P))
            EP = new_zero_ep();
    }

    if (!EP && CT->NbColumns != CT->NbRows) {
        Polyhedron *CEqr = DomainImage(CEq, CT, MaxRays);
        Polyhedron *CA = align_context(CEqr, PR->Dimension, MaxRays);
        Polyhedron *I = DomainIntersection(PR, CA, MaxRays);
        Polyhedron_Free(CEqr);
        Polyhedron_Free(CA);
#ifdef DEBUG_ER
        fprintf(stderr, "\nER: Eliminate\n");
#endif /* DEBUG_ER */
        nparam -= CT->NbColumns - CT->NbRows;
        EP = barvinok_enumerate_e(I, exist, nparam, MaxRays);
        nparam += CT->NbColumns - CT->NbRows;
        addeliminatedparams_enum(EP, CT, CEq, MaxRays, nparam);
        Polyhedron_Free(I);
    }
    if (PR != *PA)
        Polyhedron_Free(PR);
    PR = 0;

    if (!EP && nd > 1) {
#ifdef DEBUG_ER
        fprintf(stderr, "\nER: VD\n");
#endif /* DEBUG_ER */
        for (int i = 0; i < nd; ++i) {
            Polyhedron *CA = align_context(VD[i], P->Dimension, MaxRays);
            Polyhedron *I = DomainIntersection(P, CA, MaxRays);

            if (i == 0)
                EP = barvinok_enumerate_e(I, exist, nparam, MaxRays);
            else {
                evalue *E = barvinok_enumerate_e(I, exist, nparam, MaxRays);
                eadd(E, EP);
                free_evalue_refs(E); 
                free(E);
            }
            Polyhedron_Free(I);
            Polyhedron_Free(CA);
        }
    }

    for (int i = 0; i < nd; ++i) {
        Polyhedron_Free(VD[i]);
        Polyhedron_Free(fVD[i]);
    }
    delete [] VD;
    delete [] fVD;
    value_clear(c);

    if (!EP && nvar == 0) {
        Value f;
        value_init(f);
        Param_Vertices *V, *V2;
        Matrix* M = Matrix_Alloc(1, P->Dimension+2);

        FORALL_PVertex_in_ParamPolyhedron(V, last, PP) {
            bool found = false;
            FORALL_PVertex_in_ParamPolyhedron(V2, last, PP) {
                if (V == V2) {
                    found = true;
                    continue;
                }
                if (!found)
                    continue;
                for (int i = 0; i < exist; ++i) {
                    value_oppose(f, V->Vertex->p[i][nparam+1]);
                    Vector_Combine(V->Vertex->p[i],
                                   V2->Vertex->p[i],
                                   M->p[0] + 1 + nvar + exist,
                                   V2->Vertex->p[i][nparam+1],
                                   f,
                                   nparam+1);
                    int j;
                    for (j = 0; j < nparam; ++j)
                        if (value_notzero_p(M->p[0][1+nvar+exist+j]))
                            break;
                    if (j >= nparam)
                        continue;
                    ConstraintSimplify(M->p[0], M->p[0], 
                                       P->Dimension+2, &f);
                    value_set_si(M->p[0][0], 0);
                    Polyhedron *para = AddConstraints(M->p[0], 1, P,
                                                      MaxRays);
                    if (emptyQ(para)) {
                        Polyhedron_Free(para);
                        continue;
                    }
                    Polyhedron *pos, *neg;
                    value_set_si(M->p[0][0], 1);
                    value_decrement(M->p[0][P->Dimension+1],
                                    M->p[0][P->Dimension+1]);
                    neg = AddConstraints(M->p[0], 1, P, MaxRays);
                    value_set_si(f, -1);
                    Vector_Scale(M->p[0]+1, M->p[0]+1, f, 
                                 P->Dimension+1);
                    value_decrement(M->p[0][P->Dimension+1],
                                    M->p[0][P->Dimension+1]);
                    value_decrement(M->p[0][P->Dimension+1],
                                    M->p[0][P->Dimension+1]);
                    pos = AddConstraints(M->p[0], 1, P, MaxRays);
                    if (emptyQ(neg) && emptyQ(pos)) {
                        Polyhedron_Free(para);
                        Polyhedron_Free(pos);
                        Polyhedron_Free(neg);
                        continue;
                    }
#ifdef DEBUG_ER
                    fprintf(stderr, "\nER: Order\n");
#endif /* DEBUG_ER */
                    EP = barvinok_enumerate_e(para, exist, nparam, MaxRays);
                    evalue *E;
                    if (!emptyQ(pos)) {
                        E = barvinok_enumerate_e(pos, exist, nparam, MaxRays);
                        eadd(E, EP);
                        free_evalue_refs(E); 
                        free(E);
                    }
                    if (!emptyQ(neg)) {
                        E = barvinok_enumerate_e(neg, exist, nparam, MaxRays);
                        eadd(E, EP);
                        free_evalue_refs(E); 
                        free(E);
                    }
                    Polyhedron_Free(para);
                    Polyhedron_Free(pos);
                    Polyhedron_Free(neg);
                    break;
                }
                if (EP)
                    break;
            } END_FORALL_PVertex_in_ParamPolyhedron;
            if (EP)
                break;
        } END_FORALL_PVertex_in_ParamPolyhedron;

        if (!EP) {
            /* Search for vertex coordinate to split on */
            /* First look for one independent of the parameters */
            FORALL_PVertex_in_ParamPolyhedron(V, last, PP) {
                for (int i = 0; i < exist; ++i) {
                    int j;
                    for (j = 0; j < nparam; ++j)
                        if (value_notzero_p(V->Vertex->p[i][j]))
                            break;
                    if (j < nparam)
                        continue;
                    value_set_si(M->p[0][0], 1);
                    Vector_Set(M->p[0]+1, 0, nvar+exist);
                    Vector_Copy(V->Vertex->p[i], 
                                M->p[0] + 1 + nvar + exist, nparam+1);
                    value_oppose(M->p[0][1+nvar+i], 
                                 V->Vertex->p[i][nparam+1]);

                    Polyhedron *pos, *neg;
                    value_set_si(M->p[0][0], 1);
                    value_decrement(M->p[0][P->Dimension+1],
                                    M->p[0][P->Dimension+1]);
                    neg = AddConstraints(M->p[0], 1, P, MaxRays);
                    value_set_si(f, -1);
                    Vector_Scale(M->p[0]+1, M->p[0]+1, f, 
                                 P->Dimension+1);
                    value_decrement(M->p[0][P->Dimension+1],
                                    M->p[0][P->Dimension+1]);
                    value_decrement(M->p[0][P->Dimension+1],
                                    M->p[0][P->Dimension+1]);
                    pos = AddConstraints(M->p[0], 1, P, MaxRays);
                    if (emptyQ(neg) || emptyQ(pos)) {
                        Polyhedron_Free(pos);
                        Polyhedron_Free(neg);
                        continue;
                    }
                    Polyhedron_Free(pos);
                    value_increment(M->p[0][P->Dimension+1],
                                    M->p[0][P->Dimension+1]);
                    pos = AddConstraints(M->p[0], 1, P, MaxRays);
#ifdef DEBUG_ER
                    fprintf(stderr, "\nER: Vertex\n");
#endif /* DEBUG_ER */
                    pos->next = neg;
                    EP = enumerate_or(pos, exist, nparam, MaxRays);
                    break;
                }
                if (EP)
                    break;
            } END_FORALL_PVertex_in_ParamPolyhedron;
        }

        if (!EP) {
            /* Search for vertex coordinate to split on */
            /* Now look for one that depends on the parameters */
            FORALL_PVertex_in_ParamPolyhedron(V, last, PP) {
                for (int i = 0; i < exist; ++i) {
                    value_set_si(M->p[0][0], 1);
                    Vector_Set(M->p[0]+1, 0, nvar+exist);
                    Vector_Copy(V->Vertex->p[i], 
                                M->p[0] + 1 + nvar + exist, nparam+1);
                    value_oppose(M->p[0][1+nvar+i], 
                                 V->Vertex->p[i][nparam+1]);

                    Polyhedron *pos, *neg;
                    value_set_si(M->p[0][0], 1);
                    value_decrement(M->p[0][P->Dimension+1],
                                    M->p[0][P->Dimension+1]);
                    neg = AddConstraints(M->p[0], 1, P, MaxRays);
                    value_set_si(f, -1);
                    Vector_Scale(M->p[0]+1, M->p[0]+1, f, 
                                 P->Dimension+1);
                    value_decrement(M->p[0][P->Dimension+1],
                                    M->p[0][P->Dimension+1]);
                    value_decrement(M->p[0][P->Dimension+1],
                                    M->p[0][P->Dimension+1]);
                    pos = AddConstraints(M->p[0], 1, P, MaxRays);
                    if (emptyQ(neg) || emptyQ(pos)) {
                        Polyhedron_Free(pos);
                        Polyhedron_Free(neg);
                        continue;
                    }
                    Polyhedron_Free(pos);
                    value_increment(M->p[0][P->Dimension+1],
                                    M->p[0][P->Dimension+1]);
                    pos = AddConstraints(M->p[0], 1, P, MaxRays);
#ifdef DEBUG_ER
                    fprintf(stderr, "\nER: ParamVertex\n");
#endif /* DEBUG_ER */
                    pos->next = neg;
                    EP = enumerate_or(pos, exist, nparam, MaxRays);
                    break;
                }
                if (EP)
                    break;
            } END_FORALL_PVertex_in_ParamPolyhedron;
        }

        Matrix_Free(M);
        value_clear(f);
    }

    if (CEq)
        Polyhedron_Free(CEq);
    if (CT)
        Matrix_Free(CT);
    if (PP)
        Param_Polyhedron_Free(PP);
    *PA = P;

    return EP;
}

#ifndef HAVE_PIPLIB
evalue *barvinok_enumerate_pip(Polyhedron *P,
                          unsigned exist, unsigned nparam, unsigned MaxRays)
{
    return 0;
}
#else
evalue *barvinok_enumerate_pip(Polyhedron *P,
                          unsigned exist, unsigned nparam, unsigned MaxRays)
{
    int nvar = P->Dimension - exist - nparam;
    evalue *EP = new_zero_ep();
    Polyhedron *Q, *N, *T = 0;
    Value min, tmp;
    value_init(min);
    value_init(tmp);

#ifdef DEBUG_ER
    fprintf(stderr, "\nER: PIP\n");
#endif /* DEBUG_ER */

    for (int i = 0; i < P->Dimension; ++i) {
        bool pos = false;
        bool neg = false;
        bool posray = false;
        bool negray = false;
        value_set_si(min, 0);
        for (int j = 0; j < P->NbRays; ++j) {
            if (value_pos_p(P->Ray[j][1+i])) {
                pos = true;
                if (value_zero_p(P->Ray[j][1+P->Dimension]))
                    posray = true;
            } else if (value_neg_p(P->Ray[j][1+i])) {
                neg = true;
                if (value_zero_p(P->Ray[j][1+P->Dimension]))
                    negray = true;
                else {
                    mpz_fdiv_q(tmp, 
                               P->Ray[j][1+i], P->Ray[j][1+P->Dimension]);
                    if (value_lt(tmp, min))
                        value_assign(min, tmp);
                }
            }
        }
        if (pos && neg) {
            assert(!(posray && negray));
            assert(!negray);            // for now
            Polyhedron *O = T ? T : P;
            /* shift by a safe amount */
            Matrix *M = Matrix_Alloc(O->NbRays, O->Dimension+2);
            Vector_Copy(O->Ray[0], M->p[0], O->NbRays * (O->Dimension+2));
            for (int j = 0; j < P->NbRays; ++j) {
                if (value_notzero_p(M->p[j][1+P->Dimension])) {
                    value_multiply(tmp, min, M->p[j][1+P->Dimension]);
                    value_substract(M->p[j][1+i], M->p[j][1+i], tmp);
                }
            }
            if (T)
                Polyhedron_Free(T);
            T = Rays2Polyhedron(M, MaxRays);
            Matrix_Free(M);
        } else if (neg) {
            /* negating a parameter requires that we substitute in the
             * sign again afterwards.
             * Disallow for now.
             */
            assert(i < nvar+exist);
            if (!T)
                T = Polyhedron_Copy(P);
            for (int j = 0; j < T->NbRays; ++j)
                value_oppose(T->Ray[j][1+i], T->Ray[j][1+i]);
            for (int j = 0; j < T->NbConstraints; ++j)
                value_oppose(T->Constraint[j][1+i], T->Constraint[j][1+i]);
        }
    }
    value_clear(min);
    value_clear(tmp);

    Polyhedron *D = pip_lexmin(T ? T : P, exist, nparam);
    for (Q = D; Q; Q = N) {
        N = Q->next;
        Q->next = 0;
        evalue *E;
        exist = Q->Dimension - nvar - nparam;
        E = barvinok_enumerate_e(Q, exist, nparam, MaxRays);
        Polyhedron_Free(Q);
        eadd(E, EP);
        free_evalue_refs(E); 
        free(E);
    }

    if (T)
        Polyhedron_Free(T);

    return EP;
}
#endif


static bool is_single(Value *row, int pos, int len)
{
    return First_Non_Zero(row, pos) == -1 && 
           First_Non_Zero(row+pos+1, len-pos-1) == -1;
}

static evalue* barvinok_enumerate_e_r(Polyhedron *P, 
                          unsigned exist, unsigned nparam, unsigned MaxRays);

#ifdef DEBUG_ER
static int er_level = 0;

evalue* barvinok_enumerate_e(Polyhedron *P, 
                          unsigned exist, unsigned nparam, unsigned MaxRays)
{
    fprintf(stderr, "\nER: level %i\n", er_level);
    int nvar = P->Dimension - exist - nparam;
    fprintf(stderr, "%d %d %d\n", nvar, exist, nparam);

    Polyhedron_Print(stderr, P_VALUE_FMT, P);
    ++er_level;
    P = DomainConstraintSimplify(Polyhedron_Copy(P), MaxRays);
    evalue *EP = barvinok_enumerate_e_r(P, exist, nparam, MaxRays);
    Polyhedron_Free(P);
    --er_level;
    return EP;
}
#else
evalue* barvinok_enumerate_e(Polyhedron *P, 
                          unsigned exist, unsigned nparam, unsigned MaxRays)
{
    P = DomainConstraintSimplify(Polyhedron_Copy(P), MaxRays);
    evalue *EP = barvinok_enumerate_e_r(P, exist, nparam, MaxRays);
    Polyhedron_Free(P);
    return EP;
}
#endif

static evalue* barvinok_enumerate_e_r(Polyhedron *P, 
                          unsigned exist, unsigned nparam, unsigned MaxRays)
{
    if (exist == 0) {
        Polyhedron *U = Universe_Polyhedron(nparam);
        evalue *EP = barvinok_enumerate_ev(P, U, MaxRays);
        //char *param_name[] = {"P", "Q", "R", "S", "T" };
        //print_evalue(stdout, EP, param_name);
        Polyhedron_Free(U);
        return EP;
    }

    int nvar = P->Dimension - exist - nparam;
    int len = P->Dimension + 2;

    if (emptyQ(P))
        return new_zero_ep();

    if (nvar == 0 && nparam == 0) {
        evalue *EP = new_zero_ep();
        barvinok_count(P, &EP->x.n, MaxRays);
        if (value_pos_p(EP->x.n))
            value_set_si(EP->x.n, 1);
        return EP;
    }

    int r;
    for (r = 0; r < P->NbRays; ++r)
        if (value_zero_p(P->Ray[r][0]) ||
                value_zero_p(P->Ray[r][P->Dimension+1])) {
            int i;
            for (i = 0; i < nvar; ++i)
                if (value_notzero_p(P->Ray[r][i+1]))
                    break;
            if (i >= nvar)
                continue;
            for (i = nvar + exist; i < nvar + exist + nparam; ++i)
                if (value_notzero_p(P->Ray[r][i+1]))
                    break;
            if (i >= nvar + exist + nparam)
                break;
        }
    if (r <  P->NbRays) {
        evalue *EP = new_zero_ep();
        value_set_si(EP->x.n, -1);
        return EP;
    }

    int first;
    for (r = 0; r < P->NbEq; ++r)
        if ((first = First_Non_Zero(P->Constraint[r]+1+nvar, exist)) != -1)
                break;
    if (r < P->NbEq) {
        if (First_Non_Zero(P->Constraint[r]+1+nvar+first+1, 
                           exist-first-1) != -1) {
            Polyhedron *T = rotate_along(P, r, nvar, exist, MaxRays);
#ifdef DEBUG_ER
            fprintf(stderr, "\nER: Equality\n");
#endif /* DEBUG_ER */
            evalue *EP = barvinok_enumerate_e(T, exist-1, nparam, MaxRays);
            Polyhedron_Free(T);
            return EP;
        } else {
#ifdef DEBUG_ER
            fprintf(stderr, "\nER: Fixed\n");
#endif /* DEBUG_ER */
            if (first == 0)
                return barvinok_enumerate_e(P, exist-1, nparam, MaxRays);
            else {
                Polyhedron *T = Polyhedron_Copy(P);
                SwapColumns(T, nvar+1, nvar+1+first);
                evalue *EP = barvinok_enumerate_e(T, exist-1, nparam, MaxRays);
                Polyhedron_Free(T);
                return EP;
            }
        }
    }

    Vector *row = Vector_Alloc(len);
    value_set_si(row->p[0], 1);

    Value f;
    value_init(f);

    enum constraint* info = new constraint[exist];
    for (int i = 0; i < exist; ++i) {
        info[i] = ALL_POS;
        for (int l = P->NbEq; l < P->NbConstraints; ++l) {
            if (value_negz_p(P->Constraint[l][nvar+i+1]))
                continue;
            bool l_parallel = is_single(P->Constraint[l]+nvar+1, i, exist);
            for (int u = P->NbEq; u < P->NbConstraints; ++u) {
                if (value_posz_p(P->Constraint[u][nvar+i+1]))
                    continue;
                bool lu_parallel = l_parallel ||
                            is_single(P->Constraint[u]+nvar+1, i, exist);
                value_oppose(f, P->Constraint[u][nvar+i+1]);
                Vector_Combine(P->Constraint[l]+1, P->Constraint[u]+1, row->p+1,
                               f, P->Constraint[l][nvar+i+1], len-1);
                if (!(info[i] & INDEPENDENT)) {
                    int j;
                    for (j = 0; j < exist; ++j)
                        if (j != i && value_notzero_p(row->p[nvar+j+1]))
                            break;
                    if (j == exist) {
                        //printf("independent: i: %d, l: %d, u: %d\n", i, l, u);
                        info[i] = (constraint)(info[i] | INDEPENDENT);
                    }
                }
                if (info[i] & ALL_POS) {
                    value_addto(row->p[len-1], row->p[len-1], 
                              P->Constraint[l][nvar+i+1]);
                    value_addto(row->p[len-1], row->p[len-1], f);
                    value_multiply(f, f, P->Constraint[l][nvar+i+1]);
                    value_substract(row->p[len-1], row->p[len-1], f);
                    value_decrement(row->p[len-1], row->p[len-1]);
                    ConstraintSimplify(row->p, row->p, len, &f);
                    value_set_si(f, -1);
                    Vector_Scale(row->p+1, row->p+1, f, len-1);
                    value_decrement(row->p[len-1], row->p[len-1]);
                    Polyhedron *T = AddConstraints(row->p, 1, P, MaxRays);
                    if (!emptyQ(T)) {
                        //printf("not all_pos: i: %d, l: %d, u: %d\n", i, l, u);
                        info[i] = (constraint)(info[i] ^ ALL_POS);
                    }
                    //puts("pos remainder");
                    //Polyhedron_Print(stdout, P_VALUE_FMT, T);
                    Polyhedron_Free(T);
                }
                if (!(info[i] & ONE_NEG)) {
                    if (lu_parallel) {
                        negative_test_constraint(P->Constraint[l],
                                                 P->Constraint[u],
                                                 row->p, nvar+i, len, &f);
                        oppose_constraint(row->p, len, &f);
                        Polyhedron *T = AddConstraints(row->p, 1, P, MaxRays);
                        if (emptyQ(T)) {
                            //printf("one_neg i: %d, l: %d, u: %d\n", i, l, u);
                            info[i] = (constraint)(info[i] | ONE_NEG);
                        }
                        //puts("neg remainder");
                        //Polyhedron_Print(stdout, P_VALUE_FMT, T);
                        Polyhedron_Free(T);
                    }
                }
                if (!(info[i] & ALL_POS) && (info[i] & ONE_NEG))
                    goto next;
            }
        }
        if (info[i] & ALL_POS)
            break;
next:
        ;
    }

    /*
    for (int i = 0; i < exist; ++i)
        printf("%i: %i\n", i, info[i]);
    */
    for (int i = 0; i < exist; ++i)
        if (info[i] & ALL_POS) {
#ifdef DEBUG_ER
            fprintf(stderr, "\nER: Positive\n");
#endif /* DEBUG_ER */
            // Eliminate
            // Maybe we should chew off some of the fat here
            Matrix *M = Matrix_Alloc(P->Dimension, P->Dimension+1);
            for (int j = 0; j < P->Dimension; ++j)
                value_set_si(M->p[j][j + (j >= i+nvar)], 1);
            Polyhedron *T = Polyhedron_Image(P, M, MaxRays);
            Matrix_Free(M);
            evalue *EP = barvinok_enumerate_e(T, exist-1, nparam, MaxRays);
            Polyhedron_Free(T);
            value_clear(f);
            Vector_Free(row);
            delete [] info;
            return EP;
        }
    for (int i = 0; i < exist; ++i)
        if (info[i] & ONE_NEG) {
#ifdef DEBUG_ER
            fprintf(stderr, "\nER: Negative\n");
#endif /* DEBUG_ER */
            Vector_Free(row);
            value_clear(f);
            delete [] info;
            if (i == 0)
                return barvinok_enumerate_e(P, exist-1, nparam, MaxRays);
            else {
                Polyhedron *T = Polyhedron_Copy(P);
                SwapColumns(T, nvar+1, nvar+1+i);
                evalue *EP = barvinok_enumerate_e(T, exist-1, nparam, MaxRays);
                Polyhedron_Free(T);
                return EP;
            }
        }
    for (int i = 0; i < exist; ++i)
        if (info[i] & INDEPENDENT) {
            Polyhedron *pos, *neg;

            /* Find constraint again and split off negative part */

            if (SplitOnVar(P, i, nvar, len, exist, MaxRays,
                           row, f, true, &pos, &neg)) {
#ifdef DEBUG_ER
                fprintf(stderr, "\nER: Split\n");
#endif /* DEBUG_ER */

                evalue *EP = 
                    barvinok_enumerate_e(neg, exist-1, nparam, MaxRays);
                evalue *E = 
                    barvinok_enumerate_e(pos, exist, nparam, MaxRays);
                eadd(E, EP);
                free_evalue_refs(E); 
                free(E);
                Polyhedron_Free(neg);
                Polyhedron_Free(pos);
                value_clear(f);
                Vector_Free(row);
                delete [] info;
                return EP;
            }
        }
    delete [] info;

    Polyhedron *O = P;
    Polyhedron *F;

    evalue *EP;

    EP = enumerate_line(P, exist, nparam, MaxRays);
    if (EP)
        goto out;

    EP = barvinok_enumerate_pip(P, exist, nparam, MaxRays);
    if (EP)
        goto out;

    EP = enumerate_redundant_ray(P, exist, nparam, MaxRays);
    if (EP)
        goto out;

    EP = enumerate_sure(P, exist, nparam, MaxRays);
    if (EP)
        goto out;

    EP = enumerate_ray(P, exist, nparam, MaxRays);
    if (EP)
        goto out;

    EP = enumerate_sure2(P, exist, nparam, MaxRays);
    if (EP)
        goto out;

    F = unfringe(P, MaxRays);
    if (!PolyhedronIncludes(F, P)) {
#ifdef DEBUG_ER
        fprintf(stderr, "\nER: Fringed\n");
#endif /* DEBUG_ER */
        EP = barvinok_enumerate_e(F, exist, nparam, MaxRays);
        Polyhedron_Free(F);
        goto out;
    }
    Polyhedron_Free(F);

    if (nparam)
        EP = enumerate_vd(&P, exist, nparam, MaxRays);
    if (EP)
        goto out2;

    if (nvar != 0) {
        EP = enumerate_sum(P, exist, nparam, MaxRays);
        goto out2;
    }

    assert(nvar == 0);

    int i;
    Polyhedron *pos, *neg;
    for (i = 0; i < exist; ++i)
        if (SplitOnVar(P, i, nvar, len, exist, MaxRays,
                       row, f, false, &pos, &neg))
            break;

    assert (i < exist);

    pos->next = neg;
    EP = enumerate_or(pos, exist, nparam, MaxRays);

out2:
    if (O != P)
        Polyhedron_Free(P);

out:
    value_clear(f);
    Vector_Free(row);
    return EP;
}