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z3-z3-4.12.6.src.qe.nlqsat.cpp Maven / Gradle / Ivy
/*++
Copyright (c) 2015 Microsoft Corporation
Module Name:
nlqsat.cpp
Abstract:
Quantifier Satisfiability Solver for nlsat
Author:
Nikolaj Bjorner (nbjorner) 2015-10-17
Revision History:
--*/
#include "util/uint_set.h"
#include "util/scoped_ptr_vector.h"
#include "ast/expr2var.h"
#include "ast/ast_util.h"
#include "ast/rewriter/expr_safe_replace.h"
#include "ast/ast_pp.h"
#include "ast/for_each_expr.h"
#include "ast/rewriter/rewriter.h"
#include "ast/rewriter/th_rewriter.h"
#include "ast/rewriter/rewriter_def.h"
#include "ast/rewriter/quant_hoist.h"
#include "qe/nlqsat.h"
#include "qe/qsat.h"
#include "nlsat/nlsat_solver.h"
#include "nlsat/nlsat_explain.h"
#include "nlsat/nlsat_assignment.h"
#include "nlsat/tactic/goal2nlsat.h"
#include "tactic/core/tseitin_cnf_tactic.h"
namespace qe {
enum qsat_mode_t {
qsat_t,
elim_t
};
class nlqsat : public tactic {
typedef unsigned_vector assumption_vector;
typedef nlsat::scoped_literal_vector clause;
struct stats {
unsigned m_num_rounds;
stats() { reset(); }
void reset() { memset(this, 0, sizeof(*this)); }
};
struct solver_state {
ast_manager& m;
params_ref m_params;
nlsat::solver m_solver;
nlsat::literal m_is_true;
nlsat::assignment m_rmodel;
svector m_bmodel;
nlsat::assignment m_rmodel0;
svector m_bmodel0;
bool m_valid_model;
vector m_bound_rvars;
vector > m_bound_bvars;
scoped_ptr_vector m_preds;
svector m_rvar2level;
u_map m_bvar2level;
expr2var m_a2b, m_t2x;
u_map m_b2a, m_x2t;
nlsat::literal_vector m_assumptions;
nlsat::literal_vector m_asms;
nlsat::literal_vector m_cached_asms;
unsigned_vector m_cached_asms_lim;
u_map m_asm2fml;
solver_state(ast_manager& m, params_ref const& p):
m(m),
m_params(p),
m_solver(m.limit(), p, true),
m_rmodel(m_solver.am()),
m_rmodel0(m_solver.am()),
m_valid_model(false),
m_a2b(m),
m_t2x(m)
{}
~solver_state() {
reset();
}
void g2s(goal const& g) {
goal2nlsat gs;
gs(g, m_params, m_solver, m_a2b, m_t2x);
}
void init_expr2var(vector const& qvars) {
for (app_ref_vector const& qvs : qvars) {
init_expr2var(qvs);
}
}
void init_expr2var(app_ref_vector const& qvars) {
for (app* v : qvars) {
if (m.is_bool(v)) {
nlsat::bool_var b = m_solver.mk_bool_var();
m_solver.inc_ref(b);
m_a2b.insert(v, b);
}
else {
// TODO: assert it is of type Real.
m_t2x.insert(v, m_solver.mk_var(false));
}
}
}
void init_var2expr() {
for (auto const& kv : m_t2x) {
m_x2t.insert(kv.m_value, kv.m_key);
}
for (auto const& kv : m_a2b) {
m_b2a.insert(kv.m_value, kv.m_key);
}
}
void save_model(bool is_exists) {
svector bvars;
for (auto const& kv : m_bvar2level) {
bvars.push_back(kv.m_key);
}
m_solver.get_rvalues(m_rmodel);
m_solver.get_bvalues(bvars, m_bmodel);
m_valid_model = true;
if (is_exists) {
m_rmodel0.copy(m_rmodel);
m_bmodel0.reset();
m_bmodel0.append(m_bmodel);
}
}
void unsave_model() {
SASSERT(m_valid_model);
m_solver.set_rvalues(m_rmodel);
m_solver.set_bvalues(m_bmodel);
}
void clear_model() {
m_valid_model = false;
m_rmodel.reset();
m_bmodel.reset();
m_solver.set_rvalues(m_rmodel);
}
void add_assumption_literal(clause& clause, expr* fml) {
nlsat::bool_var b = m_solver.mk_bool_var();
clause.push_back(nlsat::literal(b, true));
m_assumptions.push_back(nlsat::literal(b, false));
m_solver.inc_ref(b);
m_asm2fml.insert(b, fml);
m_bvar2level.insert(b, max_level());
}
expr_ref clause2fml(nlsat::scoped_literal_vector const& clause) {
expr_ref_vector fmls(m);
expr_ref fml(m);
expr* t;
nlsat2goal n2g(m);
for (nlsat::literal l : clause) {
if (m_asm2fml.find(l.var(), t)) {
fml = t;
if (l.sign()) {
fml = push_not(fml);
}
SASSERT(l.sign());
fmls.push_back(fml);
}
else {
fmls.push_back(n2g(m_solver, m_b2a, m_x2t, l));
}
}
fml = mk_or(fmls);
return fml;
}
void add_literal(nlsat::literal_vector& lits, nlsat::literal l) {
lbool r = m_solver.value(l);
switch (r) {
case l_true:
lits.push_back(l);
break;
case l_false:
lits.push_back(~l);
break;
default:
lits.push_back(l);
break;
}
}
void display(std::ostream& out) {
out << "level " << level() << "\n";
display_preds(out);
display_assumptions(out);
m_solver.display(out << "solver:\n");
}
void display_assumptions(std::ostream& out) {
m_solver.display(out << "assumptions: ", m_asms.size(), m_asms.data());
out << "\n";
}
void display_preds(std::ostream& out) {
for (unsigned i = 0; i < m_preds.size(); ++i) {
m_solver.display(out << i << ": ", m_preds[i]->size(), m_preds[i]->data());
out << "\n";
}
}
unsigned level() const {
return m_cached_asms_lim.size();
}
void reset() {
m_asms.reset();
m_cached_asms.reset();
m_cached_asms_lim.reset();
m_is_true = nlsat::null_literal;
m_rmodel.reset();
m_valid_model = false;
m_bound_rvars.reset();
m_bound_bvars.reset();
m_preds.reset();
for (auto const& kv : m_bvar2level) {
m_solver.dec_ref(kv.m_key);
}
m_rvar2level.reset();
m_bvar2level.reset();
m_t2x.reset();
m_a2b.reset();
m_b2a.reset();
m_x2t.reset();
m_assumptions.reset();
m_asm2fml.reset();
}
};
ast_manager& m;
solver_state s;
qsat_mode_t m_mode;
params_ref m_params;
tactic_ref m_nftactic;
stats m_stats;
statistics m_st;
obj_hashtable m_free_vars;
expr_ref_vector m_answer;
expr_safe_replace m_answer_simplify;
expr_ref_vector m_trail;
ref m_div_mc;
lbool check_sat() {
while (true) {
++m_stats.m_num_rounds;
check_cancel();
init_assumptions();
lbool res = s.m_solver.check(s.m_asms);
TRACE("qe", s.display(tout << res << "\n"); );
switch (res) {
case l_true:
s.save_model(is_exists(level()));
push();
break;
case l_false:
if (0 == level()) return l_false;
if (1 == level() && m_mode == qsat_t) return l_true;
project();
break;
case l_undef:
return res;
}
}
return l_undef;
}
void init_assumptions() {
unsigned lvl = level();
s.m_asms.reset();
s.m_asms.push_back(is_exists()?s.m_is_true:~s.m_is_true);
s.m_asms.append(s.m_assumptions);
TRACE("qe", tout << "model valid: " << s.m_valid_model << " level: " << lvl << " ";
s.display_assumptions(tout);
s.m_solver.display(tout););
if (!s.m_valid_model) {
s.m_asms.append(s.m_cached_asms);
return;
}
s.unsave_model();
if (lvl == 0) {
SASSERT(s.m_cached_asms.empty());
return;
}
if (lvl <= s.m_preds.size()) {
for (unsigned j = 0; j < s.m_preds[lvl - 1]->size(); ++j) {
s.add_literal(s.m_cached_asms, (*s.m_preds[lvl - 1])[j]);
}
}
s.m_asms.append(s.m_cached_asms);
for (unsigned i = lvl + 1; i < s.m_preds.size(); i += 2) {
for (unsigned j = 0; j < s.m_preds[i]->size(); ++j) {
nlsat::literal l = (*s.m_preds[i])[j];
max_level lv = s.m_bvar2level.find(l.var());
bool use =
(lv.m_fa == i && (lv.m_ex == UINT_MAX || lv.m_ex < lvl)) ||
(lv.m_ex == i && (lv.m_fa == UINT_MAX || lv.m_fa < lvl));
if (use) {
s.add_literal(s.m_asms, l);
}
}
}
TRACE("qe", s.display(tout);
tout << "assumptions\n";
for (nlsat::literal a : s.m_asms) {
s.m_solver.display(tout, a) << "\n";
});
s.save_model(is_exists(level()));
}
template
void insert_set(S& set, T const& vec) {
for (auto const& v : vec) {
set.insert(v);
}
}
void mbp(unsigned level, nlsat::scoped_literal_vector& result) {
nlsat::var_vector vars;
uint_set fvars;
extract_vars(level, vars, fvars);
mbp(vars, fvars, result);
}
void extract_vars(unsigned level, nlsat::var_vector& vars, uint_set& fvars) {
for (unsigned i = 0; i < s.m_bound_rvars.size(); ++i) {
if (i < level) {
insert_set(fvars, s.m_bound_bvars[i]);
}
else {
vars.append(s.m_bound_rvars[i]);
}
}
}
void display_project(std::ostream& out, nlsat::var v, nlsat::scoped_literal_vector const& r1, nlsat::scoped_literal_vector const& r2) {
for (auto const& kv : s.m_x2t) {
out << "(declare-const x" << kv.m_key << " Real)\n";
}
s.m_solver.display(out << "(assert (not (exists ((", v) << " Real)) \n";
s.m_solver.display_smt2(out << "(and ", r1.size(), r1.data()) << "))))\n";
s.m_solver.display_smt2(out << "(assert (and ", r2.size(), r2.data()); out << "))\n";
out << "(check-sat)\n(reset)\n";
}
void mbp(nlsat::var_vector const& vars, uint_set const& fvars, clause& result) {
//
// Also project auxiliary variables from clausification.
//
s.unsave_model();
nlsat::explain& ex = s.m_solver.get_explain();
nlsat::scoped_literal_vector new_result(s.m_solver);
result.reset();
// project quantified Boolean variables.
for (nlsat::literal lit : s.m_asms) {
if (!s.m_b2a.contains(lit.var()) || fvars.contains(lit.var())) {
result.push_back(lit);
}
}
TRACE("qe", s.m_solver.display(tout, result.size(), result.data()); tout << "\n";);
// project quantified real variables.
// They are sorted by size, so we project the largest variables first to avoid
// renaming variables.
for (unsigned i = vars.size(); i-- > 0;) {
new_result.reset();
ex.project(vars[i], result.size(), result.data(), new_result);
TRACE("qe", display_project(tout, vars[i], result, new_result););
result.swap(new_result);
}
negate_clause(result);
}
void negate_clause(clause& result) {
for (unsigned i = 0; i < result.size(); ++i) {
result.set(i, ~result[i]);
}
}
unsigned level() const {
return s.level();
}
void enforce_parity(clause& cl) {
cl.push_back(is_exists()?~s.m_is_true:s.m_is_true);
}
void add_clause(clause& cl) {
if (cl.empty()) {
cl.push_back(~s.m_solver.mk_true());
}
SASSERT(!cl.empty());
nlsat::literal_vector lits(cl.size(), cl.data());
s.m_solver.mk_clause(lits.size(), lits.data());
}
max_level get_level(clause const& cl) {
return get_level(cl.size(), cl.data());
}
max_level get_level(unsigned n, nlsat::literal const* ls) {
max_level level;
for (unsigned i = 0; i < n; ++i) {
level.merge(get_level(ls[i]));
}
return level;
}
max_level get_level(nlsat::literal l) {
max_level level;
if (s.m_bvar2level.find(l.var(), level)) {
return level;
}
nlsat::var_vector vs;
s.m_solver.vars(l, vs);
TRACE("qe", s.m_solver.display(tout << vs << " ", l) << "\n";);
for (unsigned v : vs) {
level.merge(s.m_rvar2level.get(v, max_level()));
}
if (level == max_level())
throw default_exception("level not in NRA");
set_level(l.var(), level);
return level;
}
void set_level(nlsat::bool_var v, max_level const& level) {
unsigned k = level.max();
while (s.m_preds.size() <= k) {
s.m_preds.push_back(alloc(nlsat::scoped_literal_vector, s.m_solver));
}
nlsat::literal l(v, false);
s.m_preds[k]->push_back(l);
s.m_solver.inc_ref(v);
s.m_bvar2level.insert(v, level);
TRACE("qe", s.m_solver.display(tout, l); tout << ": " << level << "\n";);
}
void project() {
TRACE("qe", s.display_assumptions(tout););
if (!s.m_valid_model) {
pop(1);
return;
}
if (m_mode == elim_t) {
project_qe();
return;
}
SASSERT(level() >= 2);
unsigned num_scopes;
clause cl(s.m_solver);
mbp(level()-1, cl);
max_level clevel = get_level(cl);
enforce_parity(cl);
add_clause(cl);
if (clevel.max() == UINT_MAX) {
num_scopes = 2*(level()/2);
}
else {
SASSERT(clevel.max() + 2 <= level());
num_scopes = level() - clevel.max();
SASSERT(num_scopes >= 2);
}
TRACE("qe", tout << "backtrack: " << num_scopes << "\n";);
pop(num_scopes);
}
void project_qe() {
SASSERT(level() >= 1 && m_mode == elim_t && s.m_valid_model);
clause cl(s.m_solver);
mbp(std::max(1u, level()-1), cl);
expr_ref fml = s.clause2fml(cl);
TRACE("qe", tout << level() << ": " << fml << "\n";);
max_level clevel = get_level(cl);
if (level() == 1 || clevel.max() == 0) {
add_assumption_literal(cl, fml);
}
else {
enforce_parity(cl);
}
add_clause(cl);
if (level() == 1) { // is_forall() && clevel.max() == 0
add_to_answer(fml);
}
if (level() == 1) {
pop(1);
}
else {
pop(2);
}
}
void add_to_answer(expr_ref& fml) {
m_answer_simplify(fml);
expr* e;
if (m.is_not(fml, e)) {
m_answer_simplify.insert(e, m.mk_false());
}
else {
m_answer_simplify.insert(fml, m.mk_true());
}
m_answer.push_back(fml);
}
void add_assumption_literal(clause& clause, expr* fml) {
s.add_assumption_literal(clause, fml);
m_trail.push_back(fml);
}
bool is_exists() const { return is_exists(level()); }
bool is_forall() const { return is_forall(level()); }
bool is_exists(unsigned level) const { return (level % 2) == 0; }
bool is_forall(unsigned level) const { return is_exists(level+1); }
void check_cancel() {
}
struct div {
expr_ref num, den;
app_ref name;
div(ast_manager& m, expr* n, expr* d, app* nm):
num(n, m), den(d, m), name(nm, m) {}
};
class div_rewriter_cfg : public default_rewriter_cfg {
ast_manager& m;
arith_util a;
expr_ref m_zero;
vector m_divs;
public:
div_rewriter_cfg(nlqsat& s): m(s.m), a(s.m), m_zero(a.mk_real(0), m) {}
~div_rewriter_cfg() {}
br_status reduce_app(func_decl* f, unsigned sz, expr* const* args, expr_ref& result, proof_ref& pr) {
rational r1, r(1);
if (a.is_div(f) && sz == 2 && a.is_numeral(args[0], r1) && a.is_numeral(args[1], r) && !r.is_zero()) {
result = a.mk_real(r1 / r);
return BR_DONE;
}
if (is_decl_of(f, a.get_family_id(), OP_DIV) &&
sz == 2 &&
is_ground(args[0]) && is_ground(args[1])) {
result = m.mk_fresh_const("div", a.mk_real());
m_divs.push_back(div(m, args[0], args[1], to_app(result)));
return BR_DONE;
}
return BR_FAILED;
}
vector
const& divs() const { return m_divs; }
};
//template class rewriter_tpl
;
class div_rewriter_star : public rewriter_tpl {
div_rewriter_cfg m_cfg;
public:
div_rewriter_star(nlqsat& s):
rewriter_tpl(s.m, false, m_cfg),
m_cfg(s)
{}
vector const& divs() const { return m_cfg.divs(); }
};
class is_pure_proc {
nlqsat& s;
arith_util a;
bool m_has_divs;
public:
is_pure_proc(nlqsat& s): s(s), a(s.m), m_has_divs(false) {}
void operator()(::var * n) {
if (!a.is_real(n) && !s.m.is_bool(n)) {
throw tactic_exception("not NRA");
}
}
void operator()(app * n) {
if (n->get_family_id() == s.m.get_basic_family_id()) {
return;
}
if (is_uninterp_const(n) && (a.is_real(n) || s.m.is_bool(n))) {
return;
}
if (a.is_mul(n) || a.is_add(n) || a.is_sub(n) || a.is_uminus(n) || a.is_numeral(n) ||
a.is_le(n) || a.is_ge(n) || a.is_lt(n) || a.is_gt(n)) {
return;
}
expr* n1, *n2;
rational r;
if (a.is_power(n, n1, n2) && a.is_numeral(n2, r) && r.is_unsigned() && r.is_pos()) {
return;
}
if (a.is_div(n) && s.m_mode == qsat_t && is_ground(n)) {
m_has_divs = true;
return;
}
TRACE("qe", tout << "not NRA: " << mk_pp(n, s.m) << "\n";);
throw tactic_exception("not NRA");
}
void operator()(quantifier * n) {}
bool has_divs() const { return m_has_divs; }
};
/*
Ackermanize division
For each p/q:
q != 0 => div_pq*q = p
For each p/q, p'/q'
p = p', q = q' => div_pq = div_pq'
*/
void ackermanize_div(expr_ref& fml, expr_ref_vector& paxioms) {
is_pure_proc is_pure(*this);
{
expr_fast_mark1 visited;
quick_for_each_expr(is_pure, visited, fml);
}
if (is_pure.has_divs()) {
arith_util arith(m);
proof_ref pr(m);
div_rewriter_star rw(*this);
rw(fml, fml, pr);
vector
const& divs = rw.divs();
m_div_mc = alloc(generic_model_converter, m, "purify");
for (unsigned i = 0; i < divs.size(); ++i) {
expr_ref den_is0(m.mk_eq(divs[i].den, arith.mk_real(0)), m);
paxioms.push_back(m.mk_or(den_is0, m.mk_eq(divs[i].num, arith.mk_mul(divs[i].den, divs[i].name))));
for (unsigned j = i + 1; j < divs.size(); ++j) {
paxioms.push_back(m.mk_or(m.mk_not(m.mk_eq(divs[i].den, divs[j].den)),
m.mk_not(m.mk_eq(divs[i].num, divs[j].num)),
m.mk_eq(divs[i].name, divs[j].name)));
}
}
expr_ref body(arith.mk_real(0), m);
expr_ref v0(m.mk_var(0, arith.mk_real()), m);
expr_ref v1(m.mk_var(1, arith.mk_real()), m);
for (auto const& p : divs) {
body = m.mk_ite(m.mk_and(m.mk_eq(v0, p.num), m.mk_eq(v1, p.den)), p.name, body);
}
m_div_mc->add(arith.mk_div0(), body);
}
}
void reset() override {
s.reset();
m_st.reset();
s.m_solver.collect_statistics(m_st);
m_free_vars.reset();
m_answer.reset();
m_answer_simplify.reset();
m_trail.reset();
}
void push() {
s.m_cached_asms_lim.push_back(s.m_cached_asms.size());
}
void pop(unsigned num_scopes) {
s.clear_model();
unsigned new_level = level() - num_scopes;
s.m_cached_asms.shrink(s.m_cached_asms_lim[new_level]);
s.m_cached_asms_lim.shrink(new_level);
}
// expr -> nlsat::solver
bool hoist(expr_ref& fml) {
expr_ref_vector paxioms(m);
ackermanize_div(fml, paxioms);
quantifier_hoister hoist(m);
vector
qvars;
app_ref_vector vars(m);
bool is_forall = false;
pred_abs abs(m);
expr_ref fml_a(m.mk_and(fml, mk_and(paxioms)), m);
abs.get_free_vars(fml_a, vars);
insert_set(m_free_vars, vars);
qvars.push_back(vars);
vars.reset();
if (m_mode == elim_t) {
is_forall = true;
hoist.pull_quantifier(is_forall, fml, vars);
qvars.push_back(vars);
}
else {
hoist.pull_quantifier(is_forall, fml, vars);
qvars.back().append(vars);
}
do {
is_forall = !is_forall;
vars.reset();
hoist.pull_quantifier(is_forall, fml, vars);
qvars.push_back(vars);
}
while (!vars.empty());
SASSERT(qvars.size() >= 2);
SASSERT(qvars.back().empty());
s.init_expr2var(qvars);
expr_ref is_true(m), fml1(m), fml2(m);
is_true = m.mk_fresh_const("is_true", m.mk_bool_sort());
fml = m.mk_iff(is_true, fml);
goal_ref g = alloc(goal, m);
g->assert_expr(fml);
for (expr* f : paxioms) {
g->assert_expr(f);
}
expr_dependency_ref core(m);
goal_ref_buffer result;
(*m_nftactic)(g, result);
SASSERT(result.size() == 1);
TRACE("qe", result[0]->display(tout););
s.g2s(*result[0]);
// insert variables and their levels.
for (unsigned i = 0; i < qvars.size(); ++i) {
s.m_bound_bvars.push_back(svector());
s.m_bound_rvars.push_back(nlsat::var_vector());
max_level lvl;
if (is_exists(i)) lvl.m_ex = i; else lvl.m_fa = i;
for (app* v : qvars[i]) {
if (s.m_a2b.is_var(v)) {
SASSERT(m.is_bool(v));
nlsat::bool_var b = s.m_a2b.to_var(v);
TRACE("qe", tout << mk_pp(v, m) << " |-> b" << b << "\n";);
s.m_bound_bvars.back().push_back(b);
set_level(b, lvl);
}
else if (s.m_t2x.is_var(v)) {
nlsat::var w = s.m_t2x.to_var(v);
TRACE("qe", tout << mk_pp(v, m) << " |-> x" << w << "\n";);
s.m_bound_rvars.back().push_back(w);
s.m_rvar2level.setx(w, lvl, max_level());
}
else {
TRACE("qe", tout << mk_pp(v, m) << " not found\n";);
}
}
}
s.init_var2expr();
s.m_is_true = nlsat::literal(s.m_a2b.to_var(is_true), false);
// insert literals from arithmetical sub-formulas
nlsat::atom_vector const& atoms = s.m_solver.get_atoms();
TRACE("qe", s.m_solver.display(tout););
for (unsigned i = 0; i < atoms.size(); ++i) {
if (atoms[i]) {
get_level(nlsat::literal(i, false));
}
}
TRACE("qe", tout << fml << "\n";);
return true;
}
// Return false if nlsat assigned noninteger value to an integer variable.
// [copied from nlsat_tactic.cpp]
bool mk_model(model_converter_ref & mc) {
bool ok = true;
model_ref md = alloc(model, m);
arith_util util(m);
for (auto const& kv : s.m_t2x) {
nlsat::var x = kv.m_value;
expr * t = kv.m_key;
if (!is_uninterp_const(t) || !m_free_vars.contains(t))
continue;
expr * v;
try {
v = util.mk_numeral(s.m_solver.am(), s.m_rmodel0.value(x), util.is_int(t));
}
catch (z3_error & ex) {
throw ex;
}
catch (z3_exception &) {
v = util.mk_to_int(util.mk_numeral(s.m_solver.am(), s.m_rmodel0.value(x), false));
ok = false;
}
md->register_decl(to_app(t)->get_decl(), v);
}
for (auto const& kv : s.m_a2b) {
expr * a = kv.m_key;
nlsat::bool_var b = kv.m_value;
if (a == nullptr || !is_uninterp_const(a) || b == s.m_is_true.var() || !m_free_vars.contains(a))
continue;
lbool val = s.m_bmodel0.get(b, l_undef);
if (val == l_undef)
continue; // don't care
md->register_decl(to_app(a)->get_decl(), val == l_true ? m.mk_true() : m.mk_false());
}
mc = model2model_converter(md.get());
return ok;
}
public:
nlqsat(ast_manager& m, qsat_mode_t mode, params_ref const& p):
m(m),
s(m, p),
m_mode(mode),
m_params(p),
m_nftactic(nullptr),
m_answer(m),
m_answer_simplify(m),
m_trail(m),
m_div_mc(nullptr) {
s.m_solver.get_explain().set_signed_project(true);
m_nftactic = mk_tseitin_cnf_tactic(m);
}
char const* name() const override { return "nlqsat"; }
void updt_params(params_ref const & p) override {
params_ref p2(p);
p2.set_bool("factor", false);
s.m_solver.updt_params(p2);
}
void collect_param_descrs(param_descrs & r) override {
}
void operator()(/* in */ goal_ref const & in,
/* out */ goal_ref_buffer & result) override {
tactic_report report("nlqsat-tactic", *in);
ptr_vector fmls;
expr_ref fml(m);
in->get_formulas(fmls);
fml = mk_and(m, fmls.size(), fmls.data());
if (m_mode == elim_t) {
fml = m.mk_not(fml);
}
reset();
TRACE("qe", tout << fml << "\n";);
if (!hoist(fml)) {
result.push_back(in.get());
return;
}
TRACE("qe", tout << "ex: " << fml << "\n";);
lbool is_sat = check_sat();
switch (is_sat) {
case l_false:
in->reset();
in->inc_depth();
if (m_mode == elim_t) {
fml = mk_and(m_answer);
}
else {
fml = m.mk_false();
}
in->assert_expr(fml);
result.push_back(in.get());
break;
case l_true:
SASSERT(m_mode == qsat_t);
in->reset();
in->inc_depth();
result.push_back(in.get());
if (in->models_enabled()) {
model_converter_ref mc;
VERIFY(mk_model(mc));
mc = concat(m_div_mc.get(), mc.get());
in->add(mc.get());
#if 0
model_ref mdl;
model_converter2model(m, mc.get(), mdl);
for (expr* f : fmls) {
if (is_ground(f))
std::cout << mk_pp(f, m) << " |-> " << (*mdl)(f) << "\n";
}
break;
ptr_vector todo;
todo.append(fmls.size(), fmls.c_ptr());
ast_mark visited;
while (!todo.empty()) {
expr* e = todo.back();
todo.pop_back();
if (visited.is_marked(e)) continue;
visited.mark(e, true);
if (is_ground(e)) {
std::cout << mk_pp(e, m) << " |-> " << (*mdl)(e) << "\n";
}
if (is_app(e)) {
for (expr* arg : *to_app(e)) todo.push_back(arg);
}
else if (is_quantifier(e)) {
todo.push_back(to_quantifier(e)->get_expr());
}
}
#endif
}
break;
case l_undef:
result.push_back(in.get());
throw tactic_exception("search failed");
}
}
void collect_statistics(statistics & st) const override {
st.copy(m_st);
st.update("qsat num rounds", m_stats.m_num_rounds);
}
void reset_statistics() override {
m_stats.reset();
s.m_solver.reset_statistics();
}
void cleanup() override {
reset();
}
void set_logic(symbol const & l) override {
}
void set_progress_callback(progress_callback * callback) override {
}
tactic * translate(ast_manager & m) override {
return alloc(nlqsat, m, m_mode, m_params);
}
};
};
tactic * mk_nlqsat_tactic(ast_manager & m, params_ref const& p) {
return alloc(qe::nlqsat, m, qe::qsat_t, p);
}
tactic * mk_nlqe_tactic(ast_manager & m, params_ref const& p) {
return alloc(qe::nlqsat, m, qe::elim_t, p);
}