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Merge forbidden intervals for positive and negative equations

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This commit is contained in:
Jakob Rath 2022-12-13 11:42:52 +01:00
parent 6c7f556496
commit 6f1e4283bb
2 changed files with 16 additions and 50 deletions
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61
src/math/polysat/forbidden_intervals.cpp
View file

@ -181,11 +181,10 @@ namespace polysat {
SASSERT(b2.is_val());
// a*v + b <= 0, a odd
// a*v + b > 0, a odd
if (match_zero(c, a1, b1, e1, a2, b2, e2, fi))
return true;
// a*v + b > 0, a odd
if (match_non_zero_linear(c, a1, b1, e1, a2, b2, e2, fi))
return true;
if (match_linear1(c, a1, b1, e1, a2, b2, e2, fi))
return true;
if (match_linear2(c, a1, b1, e1, a2, b2, e2, fi))
@ -390,7 +389,7 @@ namespace polysat {
*
* TODO: extend to
* 2^k*a*v <= 0, a odd
* (using periodic intervals?)
* (using intervals for the lower bits of v)
*/
bool forbidden_intervals::match_zero(
signed_constraint const& c,
@ -398,52 +397,24 @@ namespace polysat {
rational const & a2, pdd const& b2, pdd const& e2,
fi_record& fi) {
_last_function = __func__;
if (c.is_positive() && a1.is_odd() && a2.is_zero() && b2.is_zero()) {
if (a1.is_odd() && a2.is_zero() && b2.is_zero()) {
auto& m = e1.manager();
rational const& mod_value = m.two_to_N();
rational a1_inv;
VERIFY(a1.mult_inverse(m.power_of_2(), a1_inv));
rational hi_val = mod(-b1.val() * a1_inv, mod_value);
pdd hi = -e1 * a1_inv;
rational lo_val = mod(hi_val + 1, mod_value);
pdd lo = hi + 1;
fi.coeff = 1;
fi.interval = eval_interval::proper(lo, lo_val, hi, hi_val);
if (b1 != e1)
fi.side_cond.push_back(s.eq(b1, e1));
if (b2 != e2)
fi.side_cond.push_back(s.eq(b2, e2));
return true;
}
return false;
}
/**
* a*v + b > 0, a odd
*
* TODO: extend to
* 2^k*a*v + b > 0, a odd
* (using periodic intervals?)
*/
bool forbidden_intervals::match_non_zero_linear(
signed_constraint const& c,
rational const & a1, pdd const& b1, pdd const& e1,
rational const & a2, pdd const& b2, pdd const& e2,
fi_record& fi) {
_last_function = __func__;
if (c.is_negative() && a1.is_odd() && a2.is_zero() && b2.is_zero()) {
// a*v + b > 0
// <=> a*v + b != 0
// <=> v + a^-1 * b != 0
// <=> v != - a^-1 * b
auto& m = e1.manager();
rational const& mod_value = m.two_to_N();
rational a1_inv;
VERIFY(a1.mult_inverse(m.power_of_2(), a1_inv));
rational lo_val(mod(-b1.val() * a1_inv, mod_value));
auto lo = -e1 * a1_inv;
rational hi_val(mod(lo_val + 1, mod_value));
auto hi = lo + 1;
// interval for a*v + b > 0 is [n,n+1[ where n = -b * a^-1
rational lo_val = mod(-b1.val() * a1_inv, mod_value);
pdd lo = -e1 * a1_inv;
rational hi_val = mod(lo_val + 1, mod_value);
pdd hi = lo + 1;
// interval for a*v + b <= 0 is the complement
if (c.is_positive()) {
std::swap(lo_val, hi_val);
std::swap(lo, hi);
}
fi.coeff = 1;
fi.interval = eval_interval::proper(lo, lo_val, hi, hi_val);
if (b1 != e1)

5
src/math/polysat/forbidden_intervals.h
View file

@ -73,11 +73,6 @@ namespace polysat {
rational const & a2, pdd const& b2, pdd const& e2,
fi_record& fi);
bool match_non_zero_linear(signed_constraint const& c,
rational const & a1, pdd const& b1, pdd const& e1,
rational const & a2, pdd const& b2, pdd const& e2,
fi_record& fi);
bool match_non_zero(signed_constraint const& c,
rational const & a1, pdd const& b1, pdd const& e1,
fi_record& fi);