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add variable minimization

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This commit is contained in:
Nikolaj Bjorner 2021-09-22 14:27:05 -07:00
parent c82bbaad7d
commit e6c413b249
6 changed files with 85 additions and 51 deletions
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64
src/math/polysat/saturation.cpp
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@ -50,9 +50,9 @@ namespace polysat {
signed_constraint inf_saturate::ineq(bool is_strict, pdd const& lhs, pdd const& rhs) {
if (is_strict)
return s().ult(lhs, rhs);
return s.ult(lhs, rhs);
else
return s().ule(lhs, rhs);
return s.ule(lhs, rhs);
}
/**
@ -60,12 +60,12 @@ namespace polysat {
* The lemmas outlined in the rules are valid and therefore c is implied.
*/
bool inf_saturate::propagate(conflict& core, inequality const& crit1, inequality const& crit2, signed_constraint& c, vector<signed_constraint>& new_constraints) {
bool crit1_false = crit1.as_signed_constraint().is_currently_false(s());
bool crit2_false = crit2.as_signed_constraint().is_currently_false(s());
bool crit1_false = crit1.as_signed_constraint().is_currently_false(s);
bool crit2_false = crit2.as_signed_constraint().is_currently_false(s);
if (!crit1_false && !crit2_false)
return false;
bool is_bool_false = c.bvalue(s()) == l_false;
bool is_model_false = c.is_currently_false(s());
bool is_bool_false = c.bvalue(s) == l_false;
bool is_model_false = c.is_currently_false(s);
if (!is_bool_false && !is_model_false)
return false;
@ -95,8 +95,8 @@ namespace polysat {
rational x_val, y_val;
auto& pddm = x.manager();
rational bound = pddm.max_value();
VERIFY(s().try_eval(x, x_val));
VERIFY(s().try_eval(y, y_val));
VERIFY(s.try_eval(x, x_val));
VERIFY(s.try_eval(y, y_val));
SASSERT(x_val * y_val <= bound);
rational x_lo = x_val, x_hi = x_max, y_lo = y_val, y_hi = y_max;
@ -140,8 +140,8 @@ namespace polysat {
// conflict resolution should be able to pick up this as a valid justification.
// or we resort to the same extension as in the original mul_overflow code
// where we add explicit equality propagations from the current assignment.
auto c1 = s().ule(x, pddm.mk_val(x_lo));
auto c2 = s().ule(y, pddm.mk_val(y_lo));
auto c1 = s.ule(x, pddm.mk_val(x_lo));
auto c2 = s.ule(y, pddm.mk_val(y_lo));
new_constraints.insert(c1);
new_constraints.insert(c2);
}
@ -154,16 +154,16 @@ namespace polysat {
rational y_max = pddm.max_value();
if (x.is_var())
x_max = s().m_viable.max_viable(x.var());
x_max = s.m_viable.max_viable(x.var());
if (y.is_var())
y_max = s().m_viable.max_viable(y.var());
y_max = s.m_viable.max_viable(y.var());
if (x_max * y_max > pddm.max_value())
push_omega_bisect(new_constraints, x, x_max, y, y_max);
else {
for (auto c : s().m_cjust[y.var()])
for (auto c : s.m_cjust[y.var()])
new_constraints.insert(c);
for (auto c : s().m_cjust[x.var()])
for (auto c : s.m_cjust[x.var()])
new_constraints.insert(c);
}
}
@ -172,14 +172,14 @@ namespace polysat {
* Match [v] .. <= v
*/
bool inf_saturate::is_l_v(pvar v, inequality const& i) {
return i.rhs == s().var(v);
return i.rhs == s.var(v);
}
/*
* Match [v] v <= ...
*/
bool inf_saturate::is_g_v(pvar v, inequality const& i) {
return i.lhs == s().var(v);
return i.lhs == s.var(v);
}
/*
@ -199,7 +199,7 @@ namespace polysat {
}
bool inf_saturate::verify_Y_l_Ax(pvar x, inequality const& d, pdd const& a, pdd const& y) {
return d.lhs == y && d.rhs == a * s().var(x);
return d.lhs == y && d.rhs == a * s.var(x);
}
/**
@ -218,7 +218,7 @@ namespace polysat {
rational x_val, y_val;
auto& pddm = x.manager();
rational bound = rational::power_of_two(pddm.power_of_2());
return s().try_eval(x, x_val) && s().try_eval(y, y_val) && x_val * y_val < bound;
return s.try_eval(x, x_val) && s.try_eval(y, y_val) && x_val * y_val < bound;
}
/**
@ -229,7 +229,7 @@ namespace polysat {
}
bool inf_saturate::verify_Xy_l_XZ(pvar v, inequality const& c, pdd const& x, pdd const& z) {
return c.lhs == s().var(v) * x && c.rhs == z * x;
return c.lhs == s.var(v) * x && c.rhs == z * x;
}
/**
@ -240,7 +240,7 @@ namespace polysat {
}
bool inf_saturate::verify_YX_l_zX(pvar z, inequality const& c, pdd const& x, pdd const& y) {
return c.lhs == y * x && c.rhs == s().var(z) * x;
return c.lhs == y * x && c.rhs == s.var(z) * x;
}
/**
@ -263,19 +263,19 @@ namespace polysat {
* [x] yx <= zx ==> Ω*(x,y) \/ y <= z \/ x = 0
*/
bool inf_saturate::try_ugt_x(pvar v, conflict& core, inequality const& c) {
pdd x = s().var(v);
pdd x = s.var(v);
pdd y = x;
pdd z = x;
if (!is_xY_l_xZ(v, c, y, z))
return false;
if (!is_non_overflow(x, y))
return false;
if (!c.is_strict && s().get_value(v).is_zero())
if (!c.is_strict && s.get_value(v).is_zero())
return false;
vector<signed_constraint> new_constraints;
if (!c.is_strict)
new_constraints.push_back(~s().eq(x));
new_constraints.push_back(~s.eq(x));
push_omega(new_constraints, x, y);
return propagate(core, c, c, c.is_strict, y, z, new_constraints);
}
@ -283,7 +283,7 @@ namespace polysat {
/// [y] z' <= y /\ zx > yx ==> Ω*(x,y) \/ zx > z'x
/// [y] z' <= y /\ yx <= zx ==> Ω*(x,y) \/ z'x <= zx
bool inf_saturate::try_ugt_y(pvar v, conflict& core, inequality const& le_y, inequality const& yx_l_zx, pdd const& x, pdd const& z) {
pdd const y = s().var(v);
pdd const y = s.var(v);
SASSERT(is_l_v(v, le_y));
SASSERT(verify_Xy_l_XZ(v, yx_l_zx, x, z));
@ -303,7 +303,7 @@ namespace polysat {
bool inf_saturate::try_ugt_y(pvar v, conflict& core, inequality const& c) {
if (!is_l_v(v, c))
return false;
pdd x = s().var(v);
pdd x = s.var(v);
pdd z = x;
for (auto dd : core) {
if (!dd->is_ule())
@ -321,7 +321,7 @@ namespace polysat {
bool inf_saturate::try_y_l_ax_and_x_l_z(pvar x, conflict& core, inequality const& c) {
if (!is_g_v(x, c))
return false;
pdd y = s().var(x);
pdd y = s.var(x);
pdd a = y;
for (auto dd : core) {
if (!dd->is_ule())
@ -353,7 +353,7 @@ namespace polysat {
bool inf_saturate::try_ugt_z(pvar z, conflict& core, inequality const& c) {
if (!is_g_v(z, c))
return false;
pdd y = s().var(z);
pdd y = s.var(z);
pdd x = y;
for (auto dd : core) {
if (!dd->is_ule())
@ -387,19 +387,19 @@ namespace polysat {
return false;
if (c.lhs.is_val() || c.rhs.is_val())
return false;
if (!c.as_signed_constraint().is_currently_false(s()))
if (!c.as_signed_constraint().is_currently_false(s))
return false;
rational l_val, r_val;
if (!s().try_eval(c.lhs, l_val))
if (!s.try_eval(c.lhs, l_val))
return false;
if (!s().try_eval(c.rhs, r_val))
if (!s.try_eval(c.rhs, r_val))
return false;
SASSERT(c.is_strict || l_val > r_val);
SASSERT(!c.is_strict || l_val >= r_val);
vector<signed_constraint> new_constraints;
new_constraints.push_back(c.as_signed_constraint());
new_constraints.push_back(s().ule(c.rhs, r_val));
return propagate(core, c, c, c.is_strict ? s().ult(c.lhs, r_val) : s().ule(c.lhs, r_val), new_constraints);
new_constraints.push_back(s.ule(c.rhs, r_val));
return propagate(core, c, c, c.is_strict ? s.ult(c.lhs, r_val) : s.ule(c.lhs, r_val), new_constraints);
}
}