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debug conflict
Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner
parent
96921355cc
commit
696db3a6a4
2 changed files with 117 additions and 58 deletions
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@ -69,11 +69,9 @@ namespace smt {
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return (a*b)/gcd(a,b);
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}
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lbool theory_pb::ineq::normalize() {
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void theory_pb::ineq::unique() {
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numeral& k = m_k;
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arg_t& args = m_args;
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// normalize first all literals to be positive:
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// then we can compare them more easily.
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for (unsigned i = 0; i < size(); ++i) {
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@ -112,6 +110,13 @@ namespace smt {
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args.pop_back();
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}
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}
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}
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lbool theory_pb::ineq::normalize() {
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numeral& k = m_k;
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arg_t& args = m_args;
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//
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// Ensure all coefficients are positive:
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// c*l + y >= k
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@ -143,14 +148,24 @@ namespace smt {
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return l_false;
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}
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// Ensure the largest coefficient is not larger than k:
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sum = 0;
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for (unsigned i = 0; i < size(); ++i) {
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numeral c = coeff(i);
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if (c > k) {
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args[i].second = k;
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}
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sum += coeff(i);
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}
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SASSERT(!args.empty());
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// normalize tight inequalities to unit coefficients.
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if (sum == k) {
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for (unsigned i = 0; i < size(); ++i) {
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args[i].second = 1;
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}
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k = size();
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}
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// apply cutting plane reduction:
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numeral g = 0;
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for (unsigned i = 0; g != 1 && i < size(); ++i) {
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@ -257,6 +272,7 @@ namespace smt {
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args[i].second = -args[i].second;
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}
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k = -k;
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c->unique();
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lbool is_true = c->normalize();
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literal lit(abv);
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@ -985,33 +1001,53 @@ namespace smt {
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}
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void theory_pb::set_mark(bool_var v, unsigned idx) {
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SASSERT(v != null_bool_var);
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if (v >= static_cast<bool_var>(m_conseq_index.size())) {
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m_conseq_index.resize(v+1, null_index);
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}
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SASSERT(!is_marked(v) || m_conseq_index[v] == idx);
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if (m_conseq_index[v] == null_index) {
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m_conseq_index[v] = idx;
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}
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}
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bool theory_pb::is_marked(bool_var v) const {
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return
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(v < static_cast<bool_var>(m_conseq_index.size())) &&
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(m_conseq_index[v] != null_index);
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}
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void theory_pb::unset_mark(literal l) {
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bool_var v = l.var();
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SASSERT(v != null_bool_var);
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if (v < static_cast<bool_var>(m_conseq_index.size())) {
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m_conseq_index[v] = null_index;
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}
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}
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void theory_pb::process_antecedent(literal l, numeral coeff) {
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context& ctx = get_context();
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bool_var v = l.var();
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unsigned lvl = ctx.get_assign_level(v);
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IF_VERBOSE(2, verbose_stream() << "ante: " << l << "*" << coeff << " " << lvl << "\n";);
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if (ctx.get_assignment(l) != l_false) {
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m_lemma.m_k -= coeff;
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}
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else if (lvl > ctx.get_base_level()) {
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if (!ctx.is_marked(v)) {
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ctx.set_mark(v);
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m_unmark.push_back(v);
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if (is_marked(v)) {
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m_lemma.m_args[m_conseq_index[v]].second += coeff;
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}
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else {
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if (lvl == m_conflict_lvl) {
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++m_num_marks;
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if (v >= static_cast<bool_var>(m_conseq_index.size())) {
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m_conseq_index.resize(v+1);
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}
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m_conseq_index[v] = m_lemma_index;
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}
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set_mark(v, m_lemma.size());
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m_lemma.m_args.push_back(std::make_pair(l, coeff));
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}
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SASSERT(m_lemma_index <= m_lemma.size());
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if (m_lemma_index == m_lemma.size()) {
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m_lemma.m_args.resize(m_lemma_index+1);
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}
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m_lemma.m_args[m_lemma_index] = std::make_pair(l, coeff);
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m_lemma_index = m_lemma.size();
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TRACE("pb_verbose", tout
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<< "ante: " << m_lemma.lit(m_conseq_index[v]) << "*"
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<< m_lemma.coeff(m_conseq_index[v]) << " " << lvl << "\n";);
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}
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}
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@ -1019,9 +1055,6 @@ namespace smt {
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//
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// Create CUT.
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// TBD only process literals that were
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// assigned below current index 'idx'.
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// and/or relevant to the conflict.
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//
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//
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@ -1050,30 +1083,24 @@ namespace smt {
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m_lemma.m_k *= g;
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}
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g = lc/coeff2;
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for (unsigned i = 0; i < c.size(); ++i) {
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if (conseq == c.lit(i)) {
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// skip this one.
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SASSERT(ctx.get_assignment(c.lit(i)) == l_true);
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}
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else {
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process_antecedent(c.lit(i), g*c.coeff(i));
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}
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}
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m_lemma.m_k += g*c.k();
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//
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// TBD: we want c.lit() to be
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// an antecedent in a real clause.
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// The coefficient 'g' is also incorrect.
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//
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// process_antecedent(~c.lit(), g);
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for (unsigned i = 0; i < c.size(); ++i) {
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process_antecedent(c.lit(i), g*c.coeff(i));
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}
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SASSERT(ctx.get_assignment(c.lit()) == l_true);
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if (ctx.get_assign_level(c.lit().var()) > ctx.get_base_level()) {
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m_antecedents.push_back(~c.lit());
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}
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}
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//
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// modeled after sat_solver/smt_context
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//
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void theory_pb::resolve_conflict(literal conseq, ineq& c) {
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IF_VERBOSE(0, verbose_stream() << "RESOLVE: " << conseq << "\n"; display(verbose_stream(), c, true););
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TRACE("pb", tout << "RESOLVE: " << conseq << "\n"; display(verbose_stream(), c, true););
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bool_var v;
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context& ctx = get_context();
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@ -1093,7 +1120,7 @@ namespace smt {
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m_num_marks = 0;
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m_lemma.reset();
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m_lemma_index = 0;
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m_antecedents.reset();
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process_ineq(c, null_literal, 1); // add consequent to lemma.
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// point into stack of assigned literals
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@ -1101,10 +1128,10 @@ namespace smt {
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SASSERT(!lits.empty());
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unsigned idx = lits.size()-1;
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do {
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while (m_num_marks > 0) {
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TRACE("pb", display(tout, m_lemma, true););
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IF_VERBOSE(0, display(verbose_stream(), m_lemma, true););
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m_lemma.normalize();
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SASSERT(m_lemma.well_formed());
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//
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// find the next marked variable in the assignment stack
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@ -1114,21 +1141,32 @@ namespace smt {
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v = conseq.var();
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--idx;
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}
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while (!ctx.is_marked(v));
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while (!is_marked(v));
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unsigned conseq_index = m_conseq_index[v];
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numeral conseq_coeff = m_lemma.coeff(conseq_index);
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m_lemma_index = conseq_index;
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TRACE("pb", display(tout, m_lemma, true);
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tout << "conseq: " << conseq << " at index: " << conseq_index << "\n";);
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SASSERT(~conseq == m_lemma.lit(conseq_index));
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// Remove conseq from lemma:
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unsigned last = m_lemma.size()-1;
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if (conseq_index != last) {
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m_lemma.m_args[conseq_index] = m_lemma.m_args[last];
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m_conseq_index[m_lemma.lit(conseq_index).var()] = conseq_index;
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}
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m_lemma.m_args.pop_back();
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unset_mark(conseq);
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--m_num_marks;
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b_justification js = ctx.get_justification(v);
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//
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// Resolve selected conseq with antecedents.
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//
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IF_VERBOSE(0, verbose_stream() << "conseq: " << conseq << " at index: " << conseq_index << "\n";);
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switch(js.get_kind()) {
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case b_justification::CLAUSE: {
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@ -1144,7 +1182,6 @@ namespace smt {
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for (unsigned i = 2; i < num_lits; ++i) {
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process_antecedent(cls.get_literal(i), conseq_coeff);
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}
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m_lemma.m_k += conseq_coeff;
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TRACE("pb", for (unsigned i = 0; i < num_lits; ++i) tout << cls.get_literal(i) << " "; tout << "\n";);
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justification* cjs = cls.get_justification();
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if (cjs) {
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@ -1154,7 +1191,6 @@ namespace smt {
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break;
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}
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case b_justification::BIN_CLAUSE:
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m_lemma.m_k += conseq_coeff;
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process_antecedent(~js.get_literal(), conseq_coeff);
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TRACE("pb", tout << "binary: " << js.get_literal() << "\n";);
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break;
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@ -1166,26 +1202,43 @@ namespace smt {
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if (j.get_from_theory() != get_id()) break;
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pb_justification& pbj = dynamic_cast<pb_justification&>(j);
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// weaken the lemma and resolve.
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TRACE("pb", display(tout, pbj.get_ineq(), true););
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process_ineq(pbj.get_ineq(), conseq, conseq_coeff);
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TRACE("pb", display(tout, pbj.get_ineq()););
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break;
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}
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default:
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UNREACHABLE();
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}
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}
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m_lemma.normalize();
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}
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while (m_num_marks > 0);
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m_lemma.normalize();
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// unset the marks on lemmas
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while (!m_unmark.empty()) {
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ctx.unset_mark(m_unmark.back());
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m_unmark.pop_back();
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for (unsigned i = 0; i < m_lemma.size(); ++i) {
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unset_mark(m_lemma.lit(i));
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}
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TRACE("pb", display(tout << "lemma: ", m_lemma););
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IF_VERBOSE(1, display(verbose_stream() << "lemma: ", m_lemma););
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// TBD:
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// create clause m_antecedents \/ m_lemma;
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//
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#if 1
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ast_manager& m = get_manager();
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svector<int> coeffs;
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expr_ref_vector args(m);
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expr_ref tmp(m);
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for (unsigned i = 0; i < m_lemma.size(); ++i) {
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ctx.literal2expr(m_lemma.lit(i), tmp);
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args.push_back(tmp);
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coeffs.push_back(static_cast<int>(m_lemma.coeff(i)));
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}
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int k = static_cast<int>(m_lemma.k());
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tmp = m_util.mk_le(coeffs.size(), coeffs.c_ptr(), args.c_ptr(), k);
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internalize_atom(to_app(tmp), false);
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m_antecedents.push_back(literal(ctx.get_bool_var(tmp)));
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justification* mjs = 0;
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ctx.mk_clause(m_antecedents.size(), m_antecedents.c_ptr(), mjs, CLS_AUX_LEMMA, 0);
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#endif
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}
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}
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@ -87,6 +87,7 @@ namespace smt {
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void negate();
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lbool normalize();
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void unique();
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bool well_formed() const;
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@ -139,10 +140,15 @@ namespace smt {
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unsigned m_num_marks;
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unsigned m_conflict_lvl;
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ineq m_lemma;
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literal_vector m_antecedents;
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// bool_var |-> index into m_lemma
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unsigned_vector m_conseq_index;
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unsigned m_lemma_index;
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svector<bool_var> m_unmark;
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void set_next_index(unsigned i);
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static const unsigned null_index = UINT_MAX;
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bool is_marked(bool_var v) const;
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void set_mark(bool_var v, unsigned idx);
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void unset_mark(literal l);
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void resolve_conflict(literal conseq, ineq& c);
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void process_antecedent(literal l, numeral coeff);
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void process_ineq(ineq& c, literal conseq, numeral coeff);
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