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add comments, fix mixup between lower/upper

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2020-05-13 13:42:50 -07:00
parent 33042268b5
commit 16aec328f1
1 changed files with 20 additions and 5 deletions
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25
src/math/lp/monomial_bounds.cpp
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@ -26,6 +26,9 @@ namespace nla {
return propagated;
}
/**
* Accumulate product of variables in monomial starting at position 'start'
*/
void monomial_bounds::compute_product(unsigned start, monic const& m, scoped_dep_interval& product) {
auto & intervals = c().m_intervals;
auto & dep_intervals = intervals.get_dep_intervals();
@ -43,26 +46,31 @@ namespace nla {
}
}
/**
* Monomial definition implies that a variable v is within 'range'
* If the current value of v is outside of the range, we add
* a bounds axiom.
*/
bool monomial_bounds::propagate_value(dep_interval& range, lpvar v) {
auto & intervals = c().m_intervals;
auto & dep_intervals = intervals.get_dep_intervals();
if (dep_intervals.is_below(range, c().val(v))) {
lp::explanation ex;
dep_intervals.get_upper_dep(range, ex);
new_lemma lemma(c(), "propagate up - upper bound of range is below value");
lemma &= ex;
auto const& upper = dep_intervals.upper(range);
auto cmp = dep_intervals.upper_is_open(range) ? llc::LT : llc::LE;
new_lemma lemma(c(), "propagate value - upper bound of range is below value");
lemma &= ex;
lemma |= ineq(v, cmp, upper);
return true;
}
else if (dep_intervals.is_above(range, c().val(v))) {
lp::explanation ex;
dep_intervals.get_lower_dep(range, ex);
new_lemma lemma(c(), "propagate up - lower bound of range is above value");
lemma &= ex;
auto const& lower = dep_intervals.upper(range);
auto const& lower = dep_intervals.lower(range);
auto cmp = dep_intervals.lower_is_open(range) ? llc::GT : llc::GE;
new_lemma lemma(c(), "propagate value - lower bound of range is above value");
lemma &= ex;
lemma |= ineq(v, cmp, lower);
return true;
}
@ -95,6 +103,13 @@ namespace nla {
}
}
/**
* Propagate bounds for monomial 'm'.
* For each variable v in m, compute the intervals of the remaining variables in m.
* Compute also the interval for m.var() as mi
* If the value of v is outside of mi / product_of_other, add a bounds lemma.
* If the value of m.var() is outside of product_of_all_vars, add a bounds lemma.
*/
bool monomial_bounds::propagate(monic const& m) {
auto & intervals = c().m_intervals;
auto & dep_intervals = intervals.get_dep_intervals();