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fix #6165

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This commit is contained in:
Nikolaj Bjorner 2022-07-30 17:09:45 +02:00
parent 5d0dea05aa
commit 4a1baa7d2d
1 changed files with 64 additions and 17 deletions
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81
src/tactic/arith/fm_tactic.cpp
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@ -61,7 +61,8 @@ class fm_tactic : public tactic {
return m.is_false(val);
}
r_kind process(func_decl * x, expr * cls, arith_util & u, model& ev, rational & r) {
r_kind process(func_decl * x, expr * cls, arith_util & u, model& ev, rational & r, expr_ref& r_e) {
r_e = nullptr;
unsigned num_lits;
expr * const * lits;
if (m.is_or(cls)) {
@ -93,6 +94,7 @@ class fm_tactic : public tactic {
expr * lhs = to_app(l)->get_arg(0);
expr * rhs = to_app(l)->get_arg(1);
rational c;
expr_ref c_e(m);
if (!u.is_numeral(rhs, c))
return NONE;
if (neg)
@ -133,27 +135,41 @@ class fm_tactic : public tactic {
expr_ref val(m);
val = ev(monomial);
rational tmp;
if (!u.is_numeral(val, tmp))
return NONE;
if (neg)
tmp.neg();
c -= tmp;
if (u.is_numeral(val, tmp)) {
if (neg)
tmp.neg();
c -= tmp;
}
else {
// this happens for algebraic numerals
if (neg)
val = u.mk_uminus(val);
if (!c_e)
c_e = u.mk_uminus(val);
else
c_e = u.mk_sub(c_e, val);
}
}
}
if (u.is_int(x->get_range()) && strict) {
// a*x < c --> a*x <= c-1
SASSERT(c.is_int());
c--;
SASSERT(!c_e);
}
is_lower = a_val.is_neg();
c /= a_val;
if (c_e)
c_e = u.mk_div(c_e, u.mk_numeral(a_val, false));
if (u.is_int(x->get_range())) {
SASSERT(!c_e);
if (is_lower)
c = ceil(c);
else
c = floor(c);
}
r = c;
r_e = c_e;
}
}
(void)found;
@ -187,6 +203,12 @@ class fm_tactic : public tactic {
//model_evaluator ev(*(md.get()));
//ev.set_model_completion(true);
arith_util u(m);
auto mk_max = [&](expr* a, expr* b) {
return expr_ref(m.mk_ite(u.mk_ge(a, b), a, b), m);
};
auto mk_min = [&](expr* a, expr* b) {
return expr_ref(m.mk_ite(u.mk_ge(a, b), b, a), m);
};
unsigned i = m_xs.size();
while (i > 0) {
--i;
@ -194,42 +216,67 @@ class fm_tactic : public tactic {
rational lower;
rational upper;
rational val;
bool has_lower = false;
bool has_upper = false;
expr_ref val_e(m), val_upper_e(m), val_lower_e(m);
bool has_lower = false, has_upper = false;
TRACE("fm_mc", tout << "processing " << x->get_name() << "\n";);
for (expr* cl : m_clauses[i]) {
if (!m.inc())
throw tactic_exception(m.limit().get_cancel_msg());
switch (process(x, cl, u, *md, val)) {
switch (process(x, cl, u, *md, val, val_e)) {
case NONE:
TRACE("fm_mc", tout << "no bound for:\n" << mk_ismt2_pp(cl, m) << "\n";);
break;
case LOWER:
TRACE("fm_mc", tout << "lower bound: " << val << " for:\n" << mk_ismt2_pp(cl, m) << "\n";);
if (!has_lower || val > lower)
lower = val;
has_lower = true;
if (val_e)
val_lower_e = val_lower_e != nullptr ? mk_max(val_lower_e, val_e) : val_e;
else if (!has_lower || val > lower)
lower = val, has_lower = true;
break;
case UPPER:
TRACE("fm_mc", tout << "upper bound: " << val << " for:\n" << mk_ismt2_pp(cl, m) << "\n";);
if (!has_upper || val < upper)
upper = val;
has_upper = true;
if (val_e)
val_upper_e = val_upper_e != nullptr ? mk_min(val_upper_e, val_e) : val_e;
else if (!has_upper || val < upper)
upper = val, has_upper = true;
break;
}
}
expr * x_val;
if (u.is_int(x->get_range())) {
if (has_lower)
if (val_lower_e) {
x_val = val_lower_e;
if (has_lower)
x_val = mk_max(x_val, u.mk_numeral(lower, true));
}
else if (val_upper_e) {
x_val = val_upper_e;
if (has_upper)
x_val = mk_min(x_val, u.mk_numeral(upper, true));
}
else if (has_lower)
x_val = u.mk_numeral(lower, true);
else if (has_upper)
x_val = u.mk_numeral(upper, true);
else
x_val = u.mk_numeral(rational(0), true);
}
else {
if (has_lower && has_upper)
if (val_lower_e && has_lower)
val_lower_e = mk_max(val_lower_e, u.mk_numeral(lower, false));
if (val_upper_e && has_upper)
val_upper_e = mk_min(val_upper_e, u.mk_numeral(upper, false));
if (val_lower_e && val_upper_e)
x_val = u.mk_div(u.mk_add(val_lower_e, val_upper_e), u.mk_real(2));
else if (val_lower_e)
x_val = u.mk_add(val_lower_e, u.mk_real(1));
else if (val_upper_e)
x_val = u.mk_sub(val_upper_e, u.mk_real(1));
else if (has_lower && has_upper)
x_val = u.mk_numeral((upper + lower)/rational(2), false);
else if (has_lower)
x_val = u.mk_numeral(lower + rational(1), false);