mirror of
https://github.com/Z3Prover/z3
synced 2025-04-23 09:05:31 +00:00
working on HS
Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner
parent
84d971b69a
commit
d7d85aa18a
1 changed files with 79 additions and 33 deletions
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@ -140,30 +140,33 @@ namespace opt {
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m_vars.push_back(m_solver.mk_var());
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}
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void add_exists_false(unsigned sz, unsigned const* S) {
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add_exists(sz, S, true);
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unsigned add_exists_false(unsigned sz, unsigned const* S) {
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return add_exists(sz, S, true);
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}
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void add_exists_true(unsigned sz, unsigned const* S) {
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add_exists(sz, S, false);
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unsigned add_exists_true(unsigned sz, unsigned const* S) {
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return add_exists(sz, S, false);
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}
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void add_exists(unsigned sz, unsigned const* S, bool sign) {
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unsigned add_exists(unsigned sz, unsigned const* S, bool sign) {
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vector<unsigned_vector>& use_list = sign?m_fuse_list:m_tuse_list;
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lbool val = sign?l_false:l_true;
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unsigned clause_id;
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vector<set>& Sets = sign?m_F:m_T;
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vector<unsigned_vector>& watch = sign?m_fwatch:m_twatch;
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SASSERT(sz > 0);
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for (unsigned i = 0; i < sz; ++i) {
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use_list[S[i]].push_back(Sets.size());
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}
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init_weights();
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init_weights();
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if (sz == 1) {
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clause_id = UINT_MAX;
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assign(S[0], val, justification(justification::AXIOM));
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}
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else {
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watch[S[0]].push_back(Sets.size());
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watch[S[1]].push_back(Sets.size());
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clause_id = Sets.size();
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watch[S[0]].push_back(clause_id);
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watch[S[1]].push_back(clause_id);
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Sets.push_back(unsigned_vector(sz, S));
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}
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add_simplex_row(!sign, sz, S);
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@ -173,6 +176,7 @@ namespace opt {
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lits.push_back(sat::literal(m_vars[S[i]], sign));
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}
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m_solver.mk_clause(lits.size(), lits.c_ptr());
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return clause_id;
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}
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lbool compute_lower() {
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@ -257,18 +261,18 @@ namespace opt {
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}
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void display(std::ostream& out) const {
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for (unsigned i = 0; i < m_weights.size(); ++i) {
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out << i << ": " << m_model[i]<< " " << m_weights[i] << "\n";
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}
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for (unsigned i = 0; i < m_T.size(); ++i) {
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display(out << "+ ", m_T[i]);
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}
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for (unsigned i = 0; i < m_F.size(); ++i) {
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display(out << "- ", m_F[i]);
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}
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out << "inconsistent: " << m_inconsistent << "\n";
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out << "weight: " << m_weight << "\n";
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out << "use lists:\n";
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for (unsigned i = 0; i < m_weights.size(); ++i) {
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out << i << ": " << value(i) << " " << m_weights[i] << "\n";
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}
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for (unsigned i = 0; i < m_T.size(); ++i) {
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display(out << "+" << i << ": ", m_T[i]);
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}
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for (unsigned i = 0; i < m_F.size(); ++i) {
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display(out << "-" << i << ": ", m_F[i]);
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}
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out << "watch lists:\n";
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for (unsigned i = 0; i < m_fwatch.size(); ++i) {
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out << i << ": ";
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for (unsigned j = 0; j < m_twatch[i].size(); ++j) {
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@ -697,9 +701,9 @@ namespace opt {
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SASSERT(!inconsistent());
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}
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if (!decide()) {
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SASSERT(validate_model());
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m_model.reset();
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m_model.append(m_value);
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SASSERT(validate_model());
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m_upper = m_weight;
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// SASSERT(m_weight < m_max_weight);
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return l_true;
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@ -714,6 +718,9 @@ namespace opt {
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for (unsigned j = 0; !found && j < S.size(); ++j) {
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found = value(S[j]) == l_true;
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}
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CTRACE("opt", !found,
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display(tout << "not found: " << i << "\n", S);
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display(tout););
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SASSERT(found);
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}
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for (unsigned i = 0; i < m_F.size(); ++i) {
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@ -722,13 +729,31 @@ namespace opt {
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for (unsigned j = 0; !found && j < S.size(); ++j) {
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found = value(S[j]) != l_true;
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}
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CTRACE("opt", !found, display(tout << "not found: " << i << "\n", S););
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CTRACE("opt", !found,
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display(tout << "not found: " << i << "\n", S);
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display(tout););
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SASSERT(found);
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}
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return true;
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}
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bool invariant() {
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for (unsigned i = 0; i < m_fwatch.size(); ++i) {
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for (unsigned j = 0; j < m_fwatch[i].size(); ++j) {
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set const& S = m_F[m_fwatch[i][j]];
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SASSERT(S[0] == i || S[1] == i);
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}
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}
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for (unsigned i = 0; i < m_twatch.size(); ++i) {
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for (unsigned j = 0; j < m_twatch[i].size(); ++j) {
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set const& S = m_T[m_twatch[i][j]];
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SASSERT(S[0] == i || S[1] == i);
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}
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}
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return true;
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}
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bool resolve_conflict() {
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while (true) {
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if (!resolve_conflict_core()) return false;
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@ -798,19 +823,23 @@ namespace opt {
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while (num_marks > 0);
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m_lemma[0] = conflict_l;
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unsigned new_scope_lvl = 0;
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TRACE("opt",
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for (unsigned i = 0; i < m_lemma.size(); ++i) {
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tout << m_lemma[i] << " ";
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tout << m_lemma[i] << " " << value(m_lemma[i]) << " ";
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}
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tout << "\n";);
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for (unsigned i = 0; i < m_lemma.size(); ++i) {
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unsigned new_scope_lvl = 0;
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for (unsigned i = 1; i < m_lemma.size(); ++i) {
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SASSERT(l_true == value(m_lemma[i]));
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new_scope_lvl = std::max(new_scope_lvl, lvl(m_lemma[i]));
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reset_mark(m_lemma[i]);
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}
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pop(scope_lvl() - new_scope_lvl);
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add_exists_false(m_lemma.size(), m_lemma.c_ptr());
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SASSERT(l_undef == value(conflict_l));
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unsigned clause_id = add_exists_false(m_lemma.size(), m_lemma.c_ptr());
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if (clause_id != UINT_MAX) {
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assign(conflict_l, l_false, justification(clause_id, false));
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}
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return true;
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}
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@ -819,7 +848,7 @@ namespace opt {
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SASSERT(alvl <= m_conflict_lvl);
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if (!is_marked(antecedent) && alvl > 0) {
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mark(antecedent);
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if (alvl == m_conflict_lvl) {
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if (alvl == m_conflict_lvl || value(antecedent) == l_false) {
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++num_marks;
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}
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else {
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@ -876,6 +905,8 @@ namespace opt {
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}
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void propagate() {
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TRACE("opt", display(tout););
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SASSERT(invariant());
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while (m_qhead < m_trail.size() && !inconsistent() && !canceled()) {
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unsigned idx = m_trail[m_qhead];
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++m_qhead;
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@ -896,9 +927,10 @@ namespace opt {
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void propagate(unsigned idx, lbool good_val, vector<unsigned_vector>& watch, vector<set>& Fs)
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{
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TRACE("opt", tout << idx << "\n";);
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TRACE("opt", tout << idx << " " << value(idx) << "\n";);
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unsigned sz = watch[idx].size();
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lbool bad_val = ~good_val;
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SASSERT(value(idx) == bad_val);
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unsigned l = 0;
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for (unsigned i = 0; i < sz && !canceled(); ++i, ++l) {
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unsigned clause_id = watch[idx][i];
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@ -925,20 +957,32 @@ namespace opt {
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if (!found) {
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if (value(F[k2]) == bad_val) {
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set_conflict(F[k2], justification(clause_id, good_val == l_true));
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return;
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for (; l <= i && i < sz; ++i, ++l) {
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watch[idx][l] = watch[idx][i];
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}
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break;
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}
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else {
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SASSERT(value(F[k2]) == l_undef);
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assign(F[k2], good_val, justification(clause_id, good_val == l_true));
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watch[idx][l] = watch[idx][i];
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}
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SASSERT(value(F[k2]) == l_undef);
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assign(F[k2], good_val, justification(clause_id, good_val == l_true));
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watch[idx][l] = watch[idx][i];
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}
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}
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watch[idx].shrink(l);
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SASSERT(invariant());
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TRACE("opt", tout << idx << " " << value(idx) << "\n";);
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SASSERT(value(idx) == bad_val);
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}
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bool infeasible_lookahead() {
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// TBD: make this more powerful
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// by using L1, L2, L3 pruning criteria.
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return (m_weight >= m_max_weight);
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}
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void prune_branch() {
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// TBD: make this more powerful
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// by using L1, L2, L3 pruning criteria.
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if (m_weight >= m_max_weight) {
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if (infeasible_lookahead()) {
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m_inconsistent = true;
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for (unsigned i = m_trail.size(); i > 0; ) {
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--i;
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@ -951,6 +995,8 @@ namespace opt {
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}
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}
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// TBD: derive strong inequalities and add them to Simplex.
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// x_i1 + .. + x_ik >= k-1 for each subset k from set n: x_1 + .. + x_n >= k
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};
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hitting_sets::hitting_sets() { m_imp = alloc(imp); }
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