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fix issues #581: nested timeouts canceled each-other
Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner
parent
a020b13f10
commit
e29adbf304
12 changed files with 96 additions and 87 deletions
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@ -20,14 +20,6 @@ Revision History:
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#include "model_based_opt.h"
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std::ostream& operator<<(std::ostream& out, opt::bound_type bt) {
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switch (bt) {
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case opt::unbounded: return out << "unbounded";
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case opt::strict: return out << "strict";
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case opt::non_strict: return out << "non-strict";
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}
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return out;
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}
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std::ostream& operator<<(std::ostream& out, opt::ineq_type ie) {
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switch (ie) {
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@ -128,8 +120,10 @@ namespace opt {
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return inf_eps::infinity();
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}
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}
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//
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// update the evaluation of variables to satisfy the bound.
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//
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update_values(bound_vars, bound_trail);
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@ -164,10 +158,10 @@ namespace opt {
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SASSERT(!x_coeff.is_zero());
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val /= -x_coeff;
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// Adjust epsilon to be s
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if (eps.is_zero() || (!val.is_zero() && eps > abs(val))) {
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if (!val.is_zero() && (eps.is_zero() || eps > abs(val))) {
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eps = abs(val)/rational(2);
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}
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if (eps.is_zero() || (!r.m_value.is_zero() && eps > abs(r.m_value))) {
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if (!r.m_value.is_zero() && (eps.is_zero() || eps > abs(r.m_value))) {
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eps = abs(r.m_value)/rational(2);
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}
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//
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@ -186,10 +180,6 @@ namespace opt {
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// <=> x > t/a
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// <=> x := t/a + epsilon
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//
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if (x_coeff.is_pos() && r.m_type == t_lt) {
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val -= eps;
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}
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else if (x_coeff.is_neg() && r.m_type == t_lt) {
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val += eps;
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}
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@ -265,48 +255,36 @@ namespace opt {
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}
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}
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// v0 - v1 <= 0
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// v0 - v2 <= 0
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// v2 >= v1
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// -> v1 - v2 <= 0
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//
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// t1 + a1*x <= 0
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// t2 + a2*x <= 0
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// (t2 + a2*x) <= (t1 + a1*x)*a2/a1
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// => t2*a1/a2 - t1 <= 0
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// => t2 - t1*a2/a1 <= 0
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// Let
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// row1: t1 + a1*x <= 0
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// row2: t2 + a2*x <= 0
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//
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// assume a1, a2 have the same signs:
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// (t2 + a2*x) <= (t1 + a1*x)*a2/a1
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// <=> t2*a1/a2 - t1 <= 0
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// <=> t2 - t1*a2/a1 <= 0
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//
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// assume a1 > 0, -a2 < 0:
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// t1 + a1*x <= 0, t2 - a2*x <= 0
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// t2/a2 <= -t1/a1
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// t2 + t1*a2/a1 <= 0
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// assume -a1 < 0, a2 > 0:
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// t1 - a1*x <= 0, t2 + a2*x <= 0
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// t1/a1 <= -t2/a2
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// t2 + t1*a2/a1 <= 0
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//
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// the resolvent is the same in all cases (simpler proof should exist)
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//
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bool model_based_opt::resolve(unsigned row_id1, rational const& a1, unsigned row_id2, unsigned x) {
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void model_based_opt::resolve(unsigned row_src, rational const& a1, unsigned row_dst, unsigned x) {
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SASSERT(a1 == get_coefficient(row_id1, x));
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SASSERT(a1 == get_coefficient(row_src, x));
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SASSERT(!a1.is_zero());
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//
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// row1 is of the form a1*x + t1 <~ 0
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// row2 is of the form a2*x + t2 <~ 0
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// assume that a1, a2 have the same sign.
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// if a1 is positive, then val(t1*a2/a1) <= val(t2*a1/a2)
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// replace row2 with the new inequality of the form:
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// t1 - a1*t2/a2 <~~ 0
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// where <~~ is strict if either <~1 or <~2 is strict.
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// if a1 is negative, then ....
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//
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row& row2 = m_rows[row_id2];
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if (!row2.m_alive) {
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return false;
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}
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rational a2 = get_coefficient(row_id2, x);
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if (a2.is_zero()) {
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return false;
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}
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if (a1.is_pos() == a2.is_pos() || row2.m_type == t_eq) {
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mul_add(row_id2, -a2/a1, row_id1);
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return true;
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}
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else {
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row2.m_alive = false;
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return false;
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if (m_rows[row_dst].m_alive) {
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rational a2 = get_coefficient(row_dst, x);
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mul_add(row_dst, -a2/a1, row_src);
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}
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}
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@ -314,6 +292,9 @@ namespace opt {
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// set row1 <- row1 + c*row2
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//
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void model_based_opt::mul_add(unsigned row_id1, rational const& c, unsigned row_id2) {
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if (c.is_zero()) {
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return;
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}
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m_new_vars.reset();
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row& r1 = m_rows[row_id1];
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row const& r2 = m_rows[row_id2];
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@ -364,6 +345,9 @@ namespace opt {
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if (r2.m_type == t_lt) {
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r1.m_type = t_lt;
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}
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else if (r2.m_type == t_le && r1.m_type == t_eq) {
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r1.m_type = t_le;
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}
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SASSERT(invariant(row_id1, r1));
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}
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@ -33,11 +33,6 @@ namespace opt {
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t_le
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};
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enum bound_type {
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unbounded,
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strict,
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non_strict
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};
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typedef inf_eps_rational<inf_rational> inf_eps;
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@ -78,7 +73,7 @@ namespace opt {
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rational get_coefficient(unsigned row_id, unsigned var_id);
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bool resolve(unsigned row_id1, rational const& a1, unsigned row_id2, unsigned x);
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void resolve(unsigned row_src, rational const& a1, unsigned row_dst, unsigned x);
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void mul_add(unsigned row_id1, rational const& c, unsigned row_id2);
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@ -118,7 +113,6 @@ namespace opt {
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}
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std::ostream& operator<<(std::ostream& out, opt::bound_type bt);
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std::ostream& operator<<(std::ostream& out, opt::ineq_type ie);
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