mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2025-04-23 09:05:31 +00:00
Code Activity

Skip redundant intervals in viable::resolve (disabled for now)

Browse source
This commit is contained in:
Jakob Rath 2022-10-03 11:03:05 +02:00
parent 0b560e5117
commit 6caa3ba1b7
1 changed files with 35 additions and 12 deletions
Download patch file Download diff file Expand all files Collapse all files

47
src/math/polysat/viable.cpp
View file

@ -633,12 +633,47 @@ namespace polysat {
if (has_viable(v))
return false;
auto* e = m_units[v];
// TODO: in the forbidden interval paper, they start with the longest interval. We should also try that at some point.
entry* first = e;
SASSERT(e);
// If there is a full interval, all others would have been removed
SASSERT(!e->interval.is_full() || e->next() == e);
SASSERT(e->interval.is_full() || all_of(*e, [](entry const& f) { return !f.interval.is_full(); }));
do {
// Build constraint: upper bound of each interval is not contained in the next interval,
// using the equivalence: t \in [l;h[ <=> t-l < h-l
entry* n = e->next();
#if 0
// Choose the next interval which furthest extends the covered region.
// Example:
// covered: [-------]
// e: [-------] <--- not required for the lemma because all points are also covered by other intervals
// n: [-------]
//
// Note that intervals are sorted by their starting points,
// so the intervals to be considered (i.e., those that
// contain the current endpoint), form a prefix of the list.
//
// Furthermore, because we remove intervals that are subsets
// of other intervals, also the endpoints must be increasing,
// so the last interval of this prefix is the best choice.
//
// current: [------[
// next: [---[ <--- impossible, would have been removed.
//
// current: [------[
// next: [-------[ <--- thus, the next interval is always the better choice.
//
// The interval 'first' is always part of the lemma. If we reach first again here, we have covered the complete domain.
while (n != first) {
entry* n1 = n->next();
if (!e->interval.currently_contains(n1->interval.lo_val()))
break;
n = n1;
}
#endif
if (!e->interval.is_full()) {
auto const& hi = e->interval.hi();
auto const& next_lo = n->interval.lo();
@ -647,18 +682,6 @@ namespace polysat {
auto rhs = next_hi - next_lo;
signed_constraint c = s.m_constraints.ult(lhs, rhs);
core.insert_eval(c);
#if 0
if (n != first) {
while {
entry* n1 = n->next();
if (n1 != first && e->currently_contains(*n1)) {
n = n1;
continue;
}
}
while (false);
}
#endif
}
for (auto sc : e->side_cond)
core.insert_eval(sc);