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working on card

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2017-01-18 15:40:39 -08:00
parent e1640fcee9
commit 238e85867a
2 changed files with 185 additions and 83 deletions
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257
src/smt/theory_pb.cpp
View file

@ -996,15 +996,15 @@ namespace smt {
bool_var abv = ctx.mk_bool_var(atom);
ctx.set_var_theory(abv, get_id());
unsigned bound = m_util.get_k(atom).get_unsigned();
literal lit(abv);
card* c = alloc(card, literal(abv), bound);
card* c = alloc(card, lit, bound);
for (unsigned i = 0; i < num_args; ++i) {
expr* arg = atom->get_arg(i);
c->add_arg(compile_arg(arg));
}
literal lit(abv);
if (c->k() == 0) {
ctx.mk_th_axiom(get_id(), 1, &lit);
@ -1016,16 +1016,7 @@ namespace smt {
dealloc(c);
}
else if (c->k() == c->size()) {
literal_vector lits;
for (unsigned i = 0; i < c->size(); ++i) {
lits.push_back(~c->lit(i));
}
lits.push_back(lit);
ctx.mk_th_axiom(get_id(), lits.size(), lits.c_ptr());
for (unsigned i = 0; i < c->size(); ++i) {
literal lits2[2] = { ~lit, c->lit(i) };
ctx.mk_th_axiom(get_id(), 2, lits2);
}
card2conjunction(*c);
dealloc(c);
}
else {
@ -1040,6 +1031,23 @@ namespace smt {
return true;
}
// \brief define cardinality constraint as conjunction.
//
void theory_pb::card2conjunction(card const& c) {
context& ctx = get_context();
literal lit = c.lit();
literal_vector lits;
for (unsigned i = 0; i < c.size(); ++i) {
lits.push_back(~c.lit(i));
}
lits.push_back(lit);
ctx.mk_th_axiom(get_id(), lits.size(), lits.c_ptr());
for (unsigned i = 0; i < c.size(); ++i) {
literal lits2[2] = { ~lit, c.lit(i) };
ctx.mk_th_axiom(get_id(), 2, lits2);
}
}
void theory_pb::watch_literal(literal lit, card* c) {
init_watch(lit.var());
ptr_vector<card>* cards = m_var_infos[lit.var()].m_lit_cwatch[lit.sign()];
@ -1112,9 +1120,12 @@ namespace smt {
if (proofs_enabled()) {
js = alloc(theory_lemma_justification, get_id(), ctx, lits.size(), lits.c_ptr());
}
resolve_conflict(c, lits);
c.inc_propagations(*this);
ctx.mk_clause(lits.size(), lits.c_ptr(), js, CLS_AUX_LEMMA, 0);
if (!resolve_conflict(c, lits)) {
ctx.mk_clause(lits.size(), lits.c_ptr(), js, CLS_AUX_LEMMA, 0);
}
std::cout << "inconsistent: " << ctx.inconsistent() << "\n";
SASSERT(ctx.inconsistent());
}
void theory_pb::add_assign(card& c, literal_vector const& lits, literal l) {
@ -1938,25 +1949,24 @@ namespace smt {
}
bool theory_pb::validate_lemma() {
uint_set seen;
int value = -m_bound;
context& ctx = get_context();
normalize_active_coeffs();
for (unsigned i = 0; i < m_active_coeffs.size(); ++i) {
bool_var v = m_active_coeffs[i];
if (seen.contains(v)) {
continue;
}
seen.insert(v);
int coeff = get_coeff(v);
if (coeff == 0) continue;
SASSERT(coeff != 0);
if (coeff < 0 && ctx.get_assignment(v) != l_true) {
value -= coeff;
}
else if (coeff > 0 && ctx.get_assignment(v) != l_false) {
value += coeff;
}
else if (coeff == 0) {
std::cout << "unexpected 0 coefficient\n";
}
}
std::cout << "bound: " << m_bound << " value " << value << " lemma is " << (value >= 0 ? "sat" : "unsat") << "\n";
std::cout << "bound: " << m_bound << " value " << value << " coeffs: " << m_active_coeffs.size() << " lemma is " << (value >= 0 ? "sat" : "unsat") << "\n";
return value < 0;
}
@ -1977,18 +1987,21 @@ namespace smt {
return arg_max;
}
literal theory_pb::cardinality_reduction() {
uint_set seen;
literal theory_pb::cardinality_reduction(card*& c) {
normalize_active_coeffs();
SASSERT(m_seen.empty());
c = 0;
int s = 0;
int new_bound = 0;
int coeff;
while (s < m_bound) {
int arg = arg_max(seen, coeff);
int arg = arg_max(m_seen, coeff);
if (arg == -1) break;
s += coeff;
++new_bound;
seen.insert(arg);
m_seen.insert(arg);
}
m_seen.reset(); // use a trail
int slack = m_bound;
for (unsigned i = 0; i < m_active_coeffs.size(); ++i) {
coeff = get_abs_coeff(m_active_coeffs[i]);
@ -2013,32 +2026,92 @@ namespace smt {
}
// create cardinality constraint
literal card_lit = null_literal;
card* c = alloc(card, card_lit, new_bound);
seen.reset();
for (unsigned i = 0; i < m_active_coeffs.size(); ++i) {
bool_var v = m_active_coeffs[i];
if (seen.contains(v)) continue;
seen.insert(v);
coeff = get_coeff(v);
if (coeff < 0) {
c->add_arg(literal(v, true));
m_coeffs[v] = -1;
}
else if (coeff > 0) {
c->add_arg(literal(v, false));
m_coeffs[v] = 1;
}
}
// display(std::cout, *c, true);
dealloc(c);
}
m_bound = new_bound;
validate_lemma();
if (validate_lemma()) {
ast_manager& m = get_manager();
context& ctx = get_context();
pb_util pb(m);
expr_ref atom(pb.mk_fresh_bool(), m);
bool_var abv = ctx.mk_bool_var(atom);
ctx.set_var_theory(abv, get_id());
card_lit = literal(abv);
c = alloc(card, card_lit, new_bound);
normalize_active_coeffs();
for (unsigned i = 0; i < m_active_coeffs.size(); ++i) {
bool_var v = m_active_coeffs[i];
if (coeff < 0) {
c->add_arg(literal(v, true));
}
else if (coeff > 0) {
c->add_arg(literal(v, false));
}
}
m_stats.m_num_predicates++;
// display(std::cout, *c, true);
if (c->k() == 0) {
UNREACHABLE();
}
else if (c->size() < c->k()) {
card_lit = false_literal;
dealloc(c);
c = 0;
}
else if (c->size() == c->k()) {
card_lit = null_literal;
unsigned lvl = UINT_MAX;
for (unsigned i = 0; i < c->size(); ++i) {
literal lit = c->lit(i);
if (ctx.get_assignment(lit) == l_false && ctx.get_assign_level(lit) < lvl) {
lvl = ctx.get_assign_level(lit);
card_lit = lit;
}
}
std::cout << "cardinality: " << card_lit << " " << atom << "\n";
dealloc(c);
c = 0;
}
else {
init_watch(abv);
m_var_infos[abv].m_card = c;
m_card_trail.push_back(abv);
}
}
return card_lit;
}
void theory_pb::normalize_active_coeffs() {
SASSERT(m_seen.empty());
unsigned i = 0, j = 0, sz = m_active_coeffs.size();
for (; i < sz; ++i) {
bool_var v = m_active_coeffs[i];
if (!m_seen.contains(v) && get_coeff(v) != 0) {
m_seen.insert(v);
if (j != i) {
m_active_coeffs[j] = m_active_coeffs[i];
}
++j;
}
}
sz = j;
m_active_coeffs.shrink(sz);
for (i = 0; i < sz; ++i) {
m_seen.remove(m_active_coeffs[i]);
}
SASSERT(m_seen.empty());
}
void theory_pb::inc_coeff(literal l, int offset) {
SASSERT(offset > 0);
bool_var v = l.var();
@ -2055,11 +2128,11 @@ namespace smt {
int coeff1 = inc + coeff0;
m_coeffs[v] = coeff1;
if (coeff0 > 0 && 0 > coeff1) {
m_bound += coeff1;
if (coeff0 > 0 && inc < 0) {
m_bound -= coeff0 - std::max(0, coeff1);
}
else if (coeff0 < 0 && 0 < coeff1) {
m_bound += coeff0;
else if (coeff0 < 0 && inc > 0) {
m_bound -= std::min(0, coeff1) + coeff0;
}
}
@ -2068,37 +2141,36 @@ namespace smt {
*/
void theory_pb::cut() {
unsigned g = 0;
for (unsigned i = 0; i < m_active_coeffs.size(); ++i) {
for (unsigned i = 0; g != 1 && i < m_active_coeffs.size(); ++i) {
bool_var v = m_active_coeffs[i];
int coeff = m_coeffs[v];
int coeff = get_abs_coeff(v);
if (coeff == 0) {
m_active_coeffs[i] = m_active_coeffs.back();
m_active_coeffs.pop_back();
continue;
}
if (coeff < 0) {
coeff = -coeff;
}
if (m_bound < coeff) {
m_coeffs[v] = m_bound;
if (m_bound < coeff) {
if (get_coeff(v) > 0) {
m_coeffs[v] = m_bound;
}
else {
m_coeffs[v] = -m_bound;
}
coeff = m_bound;
}
SASSERT(0 < coeff && coeff <= m_bound);
if (g == 0) {
g = static_cast<unsigned>(coeff);
}
else if (g != 1) {
else {
g = u_gcd(g, static_cast<unsigned>(coeff));
}
}
if (g != 1 && g != 0) {
uint_set seen;
if (g >= 2) {
normalize_active_coeffs();
for (unsigned i = 0; i < m_active_coeffs.size(); ++i) {
bool_var v = m_active_coeffs[i];
if (!seen.contains(v)) {
seen.insert(v);
m_coeffs[v] /= g;
}
m_coeffs[m_active_coeffs[i]] /= g;
}
m_bound /= g;
std::cout << "CUT " << g << "\n";
TRACE("pb", display_resolved_lemma(tout << "cut\n"););
}
}
@ -2119,6 +2191,8 @@ namespace smt {
return false;
}
std::cout << c.lit() << "\n";
reset_coeffs();
m_num_marks = 0;
m_bound = c.k();
@ -2142,22 +2216,30 @@ namespace smt {
v = conseq.var();
TRACE("pb", display_resolved_lemma(tout << conseq << "\n"););
int offset = get_coeff(v);
int offset = get_abs_coeff(v);
if (offset == 0) {
goto process_next_resolvent;
}
else if (offset < 0) {
offset = -offset;
SASSERT(validate_lemma());
if (offset > 1000) {
while (m_num_marks > 0 && idx > 0) {
v = lits[idx].var();
if (ctx.is_marked(v)) {
ctx.unset_mark(v);
}
--idx;
}
return false;
}
SASSERT(offset > 0);
js = ctx.get_justification(v);
validate_lemma();
// ctx.display(std::cout, js);
inc_coeff(conseq, offset);
//
// Resolve selected conseq with antecedents.
//
@ -2167,6 +2249,7 @@ namespace smt {
switch(js.get_kind()) {
case b_justification::CLAUSE: {
inc_coeff(conseq, offset);
clause& cls = *js.get_clause();
justification* cjs = cls.get_justification();
if (cjs && !is_proof_justification(*cjs)) {
@ -2189,6 +2272,7 @@ namespace smt {
break;
}
case b_justification::BIN_CLAUSE:
inc_coeff(conseq, offset);
process_antecedent(~js.get_literal(), offset);
TRACE("pb", tout << "binary: " << js.get_literal() << "\n";);
break;
@ -2204,11 +2288,17 @@ namespace smt {
}
if (pbj == 0) {
TRACE("pb", tout << "skip justification for " << conseq << "\n";);
inc_coeff(conseq, offset);
}
else {
process_card(pbj->get_card(), offset);
bound = pbj->get_card().k();
card& c2 = pbj->get_card();
process_card(c2, offset);
unsigned i = 0;
for (i = 0; i < c2.size() && c2.lit(i) != conseq; ++i) {}
std::cout << c2.lit() << " index at " << i << " of " << c2.size();
bound = c2.k();
}
std::cout << " offset: " << offset << " bound: " << bound << "\n";
break;
}
default:
@ -2234,36 +2324,45 @@ namespace smt {
--idx;
--m_num_marks;
}
validate_lemma();
SASSERT(validate_lemma());
TRACE("pb", display_resolved_lemma(tout << "done\n"););
uint_set seen;
normalize_active_coeffs();
int count = 0, sz = 0;
for (unsigned i = 0; i < m_active_coeffs.size(); ++i) {
bool_var v = m_active_coeffs[i];
if (seen.contains(v)) {
continue;
}
seen.insert(v);
int coeff = get_abs_coeff(v);
if (coeff == 0) continue;
SASSERT(coeff > 0);
++sz;
count += coeff;
}
std::cout << "New " << count << "(" << sz << ") >= " << m_bound << " " << c.size() << " >= " << c.k() << " new diff: " << count - m_bound << " old diff: " << c.size() - c.k() << "\n";
literal card_lit = cardinality_reduction();
card* cr = 0;
literal card_lit = cardinality_reduction(cr);
if (card_lit != null_literal) {
for (unsigned i = 0; i < m_antecedents.size(); ++i) {
m_antecedents[i].neg();
}
m_antecedents.push_back(card_lit);
ctx.mk_clause(m_antecedents.size(), m_antecedents.c_ptr(), 0, CLS_AUX_LEMMA, 0); // TBD add delete handler to GC card closure.
ctx.assign(card_lit, ctx.mk_justification(theory_propagation_justification(get_id(), ctx.get_region(), m_antecedents.size(), m_antecedents.c_ptr(), card_lit, 0, 0)));
}
return true;
if (cr != 0) {
m_antecedents.reset();
m_antecedents.push_back(card_lit);
unsigned slack = cr ? (cr->size() - cr->k()) : 0;
for (unsigned i = 0; 0 < slack && i < cr->size(); ++i) {
literal lit = cr->lit(i);
SASSERT(lit.var() != conseq.var() || lit == ~conseq);
if (lit.var() != conseq.var() && ctx.get_assignment(lit) == l_false) {
m_antecedents.push_back(~lit);
--slack;
}
}
ctx.assign(~conseq, ctx.mk_justification(theory_propagation_justification(get_id(), ctx.get_region(), m_antecedents.size(), m_antecedents.c_ptr(), ~conseq, 0, 0)));
std::cout << conseq << " " << ctx.get_assignment(conseq) << "\n";
}
return card_lit != null_literal;
}
bool theory_pb::is_proof_justification(justification const& j) const {

11
src/smt/theory_pb.h
View file

@ -324,6 +324,7 @@ namespace smt {
unsigned_vector m_card_lim;
bool is_cardinality_constraint(app * atom);
bool internalize_card(app * atom, bool gate_ctx);
void card2conjunction(card const& c);
void watch_literal(literal lit, card* c);
void unwatch_literal(literal w, card* c);
@ -367,20 +368,22 @@ namespace smt {
unsigned m_num_marks;
unsigned_vector m_resolved;
unsigned m_conflict_lvl;
// Conflict PB constraints
svector<int> m_coeffs;
svector<bool_var> m_active_coeffs;
int m_bound;
literal_vector m_antecedents;
uint_set m_seen;
void normalize_active_coeffs();
void inc_coeff(literal l, int offset);
int get_coeff(bool_var v) const;
int get_abs_coeff(bool_var v) const;
int get_abs_coeff(bool_var v) const;
int arg_max(uint_set& seen, int& coeff);
void reset_coeffs();
literal cardinality_reduction();
literal cardinality_reduction(card*& c);
bool resolve_conflict(card& c, literal_vector const& conflict_clause);
void process_antecedent(literal l, int offset);