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fixes

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This commit is contained in:
Nikolaj Bjorner 2021-12-21 21:31:59 -08:00
parent bc553c1f50
commit 8fd89c5e15
1 changed files with 97 additions and 61 deletions
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158
src/solver/smtmus.cpp
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@ -69,6 +69,8 @@ struct smtmus::imp {
for (auto& [w, coeff] : m_coeffs)
if (v != w && mdl.eval(w, val) && a.is_numeral(val, r))
value += r * coeff;
value.neg();
adjust_value(a, v, value);
return value;
}
@ -76,17 +78,20 @@ struct smtmus::imp {
void adjust_value(arith_util& a, func_decl* v, rational& value) {
bool is_int = a.is_int(v->get_range());
rational coeff = m_coeffs[v];
// coeff * v <= value or coeff * v < value
value = value / coeff;
if (is_int)
value = floor(value);
// v <= value / v < value or when coeff < 0: v >= value/ v > value
bool is_rounded = !value.is_int();
if (is_int && is_rounded)
value = coeff.is_pos() ? floor(value) : ceil(value);
switch (m_kind) {
case ineq_kind::LE:
break;
case ineq_kind::LT:
if (is_int)
value += 1;
else
value += rational(0.00001);
if (!is_int)
value += rational(coeff.is_pos() ? 0.001 : -0.001);
else if (!is_rounded)
value += coeff.is_pos() ? -1 : 1;
break;
default:
break;
@ -128,65 +133,96 @@ struct smtmus::imp {
m_soft.push_back(lit);
}
// initialize soft_clauses based on control variables in mus, or if mus already is a clause.
void init_soft_clauses() {
obj_map<expr, unsigned> lit2clause;
vector<expr_ref_vector> clauses;
obj_hashtable<expr> softs;
bool initialized = false;
auto init_lit2clause = [&]() {
if (initialized)
return;
initialized = true;
for (expr* s : m_soft)
softs.insert(s);
for (auto* f : m_solver.get_assertions()) {
expr_ref_vector ors(m);
flatten_or(f, ors);
unsigned idx = 0;
bool is_soft = false;
for (expr* e : ors) {
expr* s = nullptr;
if (m.is_not(e, s) && softs.contains(s)) {
ors[idx] = ors.back();
ors.pop_back();
if (lit2clause.find(s, idx)) {
expr_ref cl(m.mk_and(mk_or(clauses[idx]), mk_or(ors)), m);
ors.reset();
ors.push_back(cl);
clauses[idx].reset();
clauses[idx].append(ors);
}
else {
lit2clause.insert(s, clauses.size());
clauses.push_back(ors);
}
is_soft = true;
break;
}
++idx;
}
if (!is_soft)
m_hard.push_back(f);
}
};
unsigned cl;
void init_soft_clauses() {
obj_hashtable<expr> dups;
obj_map<expr, unsigned> soft2hard;
obj_map<expr, unsigned> softs;
u_map<expr*> hard2soft;
unsigned idx = 0;
// initialize hard clauses
m_hard.reset();
m_hard.append(m_solver.get_assertions());
// initialize soft clauses.
m_soft_clauses.reset();
for (expr* s : m_soft)
m_soft_clauses.push_back(expr_ref_vector(m, 1, &s));
// collect indicator variable candidates
for (expr* s : m_soft) {
expr_ref_vector clause(m);
if (m.is_or(s))
clause.append(to_app(s)->get_num_args(), to_app(s)->get_args());
else if (is_uninterp_const(s)) {
init_lit2clause();
if (lit2clause.find(s, cl))
clause.append(clauses[cl]);
if (is_uninterp_const(s)) {
if (softs.contains(s))
dups.insert(s);
else
clause.push_back(s);
softs.insert(s, idx);
}
else
clause.push_back(s);
m_soft_clauses.push_back(clause);
++idx;
}
for (auto* s : dups)
softs.remove(s);
if (softs.empty())
return;
// find all clauses where soft indicators are used.
idx = 0;
for (expr* f : m_hard) {
expr_ref_vector ors(m);
flatten_or(f, ors);
for (expr* e : ors) {
expr* s = nullptr;
if (m.is_not(e, s) && softs.contains(s)) {
soft2hard.insert(s, idx);
hard2soft.insert(idx, s);
break;
}
}
++idx;
}
// remove hard2soft associations if soft clauses don't occur uniquely.
idx = 0;
unsigned_vector to_remove;
for (expr* f : m_hard) {
for (expr* v : subterms::all(expr_ref(f, m))) {
unsigned idx2;
if (is_uninterp_const(v) && soft2hard.find(v, idx2) && idx != idx2) {
to_remove.push_back(idx2);
to_remove.push_back(idx);
}
}
++idx;
}
for (auto i : to_remove)
hard2soft.remove(i);
//
// update soft clauses using hard clauses.
// for soft clause s0 and hard clause ~s0 or lit1 or lit2,
// replace s0 by (lit1 or lit2), and replace hard clause by true.
//
idx = 0;
for (auto const& [i, s] : hard2soft) {
expr* f = m_hard.get(i);
expr_ref_vector ors(m);
flatten_or(f, ors);
idx = 0;
for (expr* e : ors) {
unsigned j;
expr* s2 = nullptr;
if (m.is_not(e, s2) && softs.find(s2, j)) {
ors[idx] = ors.back();
ors.pop_back();
m_soft_clauses[j].reset();
m_soft_clauses[j].append(ors);
break;
}
++idx;
}
SASSERT(idx < ors.size());
m_hard[i] = m.mk_true();
}
TRACE("satmus",
for (expr* s : m_soft)
tout << "soft " << mk_pp(s, m) << "\n";
@ -253,6 +289,7 @@ struct smtmus::imp {
auto* e = alloc(ineq, m, is_strict ? ineq_kind::LT : ineq_kind::LE);
expr_ref_vector basis(m);
rational coeff1;
// encode x - y <= 0 or x - y < 0
vector<std::pair<rational, expr*>> terms;
terms.push_back(std::make_pair(rational::one(), x));
terms.push_back(std::make_pair(-rational::one(), y));
@ -513,7 +550,6 @@ struct smtmus::imp {
return flips;
}
expr_ref_vector rotate_get_flips_agnostic(expr* lit, func_decl* v, model& mdl, unsigned limit) {
solver_ref s2 = mk_smt2_solver(m, m_solver.get_params());
s2->assert_expr(lit);