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working on incremtal PB theory

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2014-01-13 10:12:45 -08:00
parent 1f7c994e43
commit 236b2d2ff3
12 changed files with 1419 additions and 912 deletions
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54
src/ast/rewriter/pb_rewriter_def.h
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@ -23,20 +23,20 @@ Notes:
template<typename PBU>
void pb_rewriter_util<PBU>::display(std::ostream& out, typename PBU::args_t& args, typename PBU::numeral& k) {
void pb_rewriter_util<PBU>::display(std::ostream& out, typename PBU::args_t& args, typename PBU::numeral& k, bool is_eq) {
for (unsigned i = 0; i < args.size(); ++i) {
out << args[i].second << " * ";
m_util.display(out, args[i].first);
out << " ";
if (i+1 < args.size()) out << "+ ";
}
out << " >= " << k << "\n";
out << (is_eq?" = ":" >= ") << k << "\n";
}
template<typename PBU>
void pb_rewriter_util<PBU>::unique(typename PBU::args_t& args, typename PBU::numeral& k) {
void pb_rewriter_util<PBU>::unique(typename PBU::args_t& args, typename PBU::numeral& k, bool is_eq) {
TRACE("pb_verbose", display(tout << "pre-unique:", args, k););
TRACE("pb_verbose", display(tout << "pre-unique:", args, k, is_eq););
for (unsigned i = 0; i < args.size(); ++i) {
if (m_util.is_negated(args[i].first)) {
args[i].first = m_util.negate(args[i].first);
@ -85,19 +85,19 @@ void pb_rewriter_util<PBU>::unique(typename PBU::args_t& args, typename PBU::num
}
}
args.resize(i);
TRACE("pb_verbose", display(tout << "post-unique:", args, k););
TRACE("pb_verbose", display(tout << "post-unique:", args, k, is_eq););
}
template<typename PBU>
lbool pb_rewriter_util<PBU>::normalize(typename PBU::args_t& args, typename PBU::numeral& k) {
TRACE("pb_verbose", display(tout << "pre-normalize:", args, k););
lbool pb_rewriter_util<PBU>::normalize(typename PBU::args_t& args, typename PBU::numeral& k, bool is_eq) {
TRACE("pb_verbose", display(tout << "pre-normalize:", args, k, is_eq););
DEBUG_CODE(
bool found = false;
for (unsigned i = 0; !found && i < args.size(); ++i) {
found = args[i].second.is_zero();
}
if (found) display(verbose_stream(), args, k);
if (found) display(verbose_stream(), args, k, is_eq);
SASSERT(!found););
//
@ -121,17 +121,29 @@ lbool pb_rewriter_util<PBU>::normalize(typename PBU::args_t& args, typename PBU:
sum += args[i].second;
}
// detect tautologies:
if (k <= PBU::numeral::zero()) {
if (!is_eq && k <= PBU::numeral::zero()) {
args.reset();
k = PBU::numeral::zero();
return l_true;
}
if (is_eq && k.is_zero() && args.empty()) {
return l_true;
}
// detect infeasible constraints:
if (sum < k) {
args.reset();
k = PBU::numeral::one();
return l_false;
}
if (is_eq && k == sum) {
for (unsigned i = 0; i < args.size(); ++i) {
args[i].second = PBU::numeral::one();
}
k = PBU::numeral::one();
return l_undef;
}
bool all_int = true;
for (unsigned i = 0; all_int && i < args.size(); ++i) {
@ -150,6 +162,11 @@ lbool pb_rewriter_util<PBU>::normalize(typename PBU::args_t& args, typename PBU:
args[i].second *= d;
}
}
if (is_eq) {
TRACE("pb_verbose", display(tout << "post-normalize:", args, k, is_eq););
return l_undef;
}
// Ensure the largest coefficient is not larger than k:
sum = PBU::numeral::zero();
@ -193,7 +210,7 @@ lbool pb_rewriter_util<PBU>::normalize(typename PBU::args_t& args, typename PBU:
}
else if (g > PBU::numeral::one()) {
IF_VERBOSE(3, verbose_stream() << "cut " << g << "\n";
display(verbose_stream(), args, k);
display(verbose_stream(), args, k, is_eq);
);
//
@ -241,7 +258,7 @@ lbool pb_rewriter_util<PBU>::normalize(typename PBU::args_t& args, typename PBU:
PBU::numeral n1 = floor(n0);
PBU::numeral n2 = ceil(k/min) - PBU::numeral::one();
if (n1 == n2 && !n0.is_int()) {
IF_VERBOSE(3, display(verbose_stream() << "set cardinality\n", args, k););
IF_VERBOSE(3, display(verbose_stream() << "set cardinality\n", args, k, is_eq););
for (unsigned i = 0; i < args.size(); ++i) {
args[i].second = PBU::numeral::one();
@ -249,13 +266,15 @@ lbool pb_rewriter_util<PBU>::normalize(typename PBU::args_t& args, typename PBU:
k = n1 + PBU::numeral::one();
}
}
TRACE("pb_verbose", display(tout << "post-normalize:", args, k, is_eq););
return l_undef;
}
template<typename PBU>
void pb_rewriter_util<PBU>::prune(typename PBU::args_t& args, typename PBU::numeral& k) {
void pb_rewriter_util<PBU>::prune(typename PBU::args_t& args, typename PBU::numeral& k, bool is_eq) {
if (is_eq) {
return;
}
PBU::numeral nlt(0);
unsigned occ = 0;
for (unsigned i = 0; nlt < k && i < args.size(); ++i) {
@ -264,8 +283,7 @@ void pb_rewriter_util<PBU>::prune(typename PBU::args_t& args, typename PBU::nume
++occ;
}
}
if (0 < occ && nlt < k) {
if (0 < occ && nlt < k) {
for (unsigned i = 0; i < args.size(); ++i) {
if (args[i].second < k) {
args[i] = args.back();
@ -273,8 +291,8 @@ void pb_rewriter_util<PBU>::prune(typename PBU::args_t& args, typename PBU::nume
--i;
}
}
unique(args, k);
normalize(args, k);
unique(args, k, is_eq);
normalize(args, k, is_eq);
}
}