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extend monomial bounds to handle powers

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2020-05-14 19:13:17 -07:00
parent 73fa5995d4
commit b43ed70874
4 changed files with 151 additions and 99 deletions

View file

@ -11,53 +11,56 @@
namespace nla {
struct tangent_imp {
point m_a;
point m_b;
point m_xy;
rational m_correct_v;
class tangent_imp {
point m_a;
point m_b;
point m_xy;
rational m_correct_v;
// "below" means that the incorrect value is less than the correct one, that is m_v < m_correct_v
bool m_below;
rational m_v; // the monomial value
lpvar m_j; // the monic variable
const monic& m_m;
bool m_below;
rational m_v; // the monomial value
lpvar m_j; // the monic variable
const monic& m_m;
const factor& m_x;
const factor& m_y;
lpvar m_jx;
lpvar m_jy;
tangents& m_tang;
bool m_is_mon;
lpvar m_jx;
lpvar m_jy;
tangents& m_tang;
bool m_is_mon;
public:
tangent_imp(point xy,
const rational& v,
lpvar j, // the monic variable
const monic& m,
const factorization& f,
tangents& tang) : m_xy(xy),
m_correct_v(xy.x * xy.y),
m_below(v < m_correct_v),
m_v(v),
m_j(tang.var(m)),
m_j(m.var()),
m_m(m),
m_x(f[0]),
m_y(f[1]),
m_jx(tang.var(m_x)),
m_jy(tang.var(m_y)),
m_jx(m_x.var()),
m_jy(m_y.var()),
m_tang(tang),
m_is_mon(f.is_mon()) {
SASSERT(f.size() == 2);
}
core & c() { return m_tang.c(); }
void tangent_lemma_on_bf() {
get_tang_points();
TRACE("nla_solver", tout << "tang domain = "; print_tangent_domain(tout) << std::endl;);
generate_two_tang_lines();
generate_tang_plane(m_a);
generate_tang_plane(m_b);
void operator()() {
get_points();
TRACE("nla_solver", print_tangent_domain(tout << "tang domain = ") << std::endl;);
generate_line1();
generate_line2();
generate_plane(m_a);
generate_plane(m_b);
}
private:
core & c() { return m_tang.c(); }
void explain(new_lemma& lemma) {
if (!m_is_mon) {
lemma &= m_m;
@ -66,7 +69,7 @@ struct tangent_imp {
}
}
void generate_tang_plane(const point & pl) {
void generate_plane(const point & pl) {
new_lemma lemma(c(), "generate tangent plane");
c().negate_relation(lemma, m_jx, m_x.rat_sign()*pl.x);
c().negate_relation(lemma, m_jy, m_y.rat_sign()*pl.y);
@ -86,24 +89,24 @@ struct tangent_imp {
lemma |= ineq(t, m_below? llc::GT : llc::LT, - pl.x*pl.y);
explain(lemma);
}
void generate_two_tang_lines() {
{
new_lemma lemma(c(), "two tangent planes 1");
// Should be v = val(m_x)*val(m_y), and val(factor) = factor.rat_sign()*var(factor.var())
lemma |= ineq(m_jx, llc::NE, c().val(m_jx));
lemma |= ineq(lp::lar_term(m_j, - m_y.rat_sign() * m_xy.x, m_jy), llc::EQ, 0);
explain(lemma);
}
{
new_lemma lemma(c(), "two tangent planes 2");
lemma |= ineq(m_jy, llc::NE, c().val(m_jy));
lemma |= ineq(lp::lar_term(m_j, - m_x.rat_sign() * m_xy.y, m_jx), llc::EQ, 0);
explain(lemma);
}
void generate_line1() {
new_lemma lemma(c(), "tangent line 1");
// Should be v = val(m_x)*val(m_y), and val(factor) = factor.rat_sign()*var(factor.var())
lemma |= ineq(m_jx, llc::NE, c().val(m_jx));
lemma |= ineq(lp::lar_term(m_j, - m_y.rat_sign() * m_xy.x, m_jy), llc::EQ, 0);
explain(lemma);
}
void generate_line2() {
new_lemma lemma(c(), "tangent line 2");
lemma |= ineq(m_jy, llc::NE, c().val(m_jy));
lemma |= ineq(lp::lar_term(m_j, - m_x.rat_sign() * m_xy.y, m_jx), llc::EQ, 0);
explain(lemma);
}
// Get two planes tangent to surface z = xy, one at point a, and another at point b, creating a cut
void get_initial_tang_points() {
void get_initial_points() {
const rational& x = m_xy.x;
const rational& y = m_xy.y;
bool all_ints = m_v.is_int() && x.is_int() && y.is_int();
@ -130,7 +133,7 @@ struct tangent_imp {
}
}
void push_tang_point(point & a) {
void push_point(point & a) {
SASSERT(plane_is_correct_cut(a));
int steps = 10;
point del = a - m_xy;
@ -139,7 +142,7 @@ struct tangent_imp {
point na = m_xy + del;
TRACE("nla_solver_tp", tout << "del = " << del << std::endl;);
if (!plane_is_correct_cut(na)) {
TRACE("nla_solver_tp", tout << "exit";tout << std::endl;);
TRACE("nla_solver_tp", tout << "exit\n";);
return;
}
a = na;
@ -147,25 +150,24 @@ struct tangent_imp {
}
rational tang_plane(const point& a) const {
return a.x * m_xy.y + a.y * m_xy.x - a.x * a.y;
return a.x * m_xy.y + a.y * m_xy.x - a.x * a.y;
}
void get_tang_points() {
get_initial_tang_points();
void get_points() {
get_initial_points();
TRACE("nla_solver", tout << "xy = " << m_xy << ", correct val = " << m_correct_v;
tout << "\ntang points:"; print_tangent_domain(tout);tout << std::endl;);
push_tang_point(m_a);
TRACE("nla_solver", tout << "pushed a = " << m_a << std::endl;);
push_tang_point(m_b);
TRACE("nla_solver", tout << "pushed b = " << m_b << std::endl;);
print_tangent_domain(tout << "\ntang points:") << std::endl;);
push_point(m_a);
push_point(m_b);
TRACE("nla_solver",
tout << "tang_plane(a) = " << tang_plane(m_a) << " , val = " << m_v << ", tang_plane(b) = " << tang_plane(m_b) << " , val = " << std::endl;);
tout << "pushed a = " << m_a << std::endl
<< "pushed b = " << m_b << std::endl
<< "tang_plane(a) = " << tang_plane(m_a) << " , val = " << m_a << ", "
<< "tang_plane(b) = " << tang_plane(m_b) << " , val = " << m_b << std::endl;);
}
std::ostream& print_tangent_domain(std::ostream& out) {
out << "(" << m_a << ", " << m_b << ")";
return out;
return out << "(" << m_a << ", " << m_b << ")";
}
bool plane_is_correct_cut(const point& plane) const {
@ -173,7 +175,7 @@ struct tangent_imp {
tout << "tang_plane() = " << tang_plane(plane) << ", v = " << m_v << ", correct_v = " << m_correct_v << "\n";);
SASSERT((m_below && m_v < m_correct_v) ||
((!m_below) && m_v > m_correct_v));
rational sign = m_below? rational(1) : rational(-1);
rational sign = rational(m_below ? 1 : -1);
rational px = tang_plane(plane);
return ((m_correct_v - px)*sign).is_pos() && !((px - m_v)*sign).is_neg();
}
@ -182,21 +184,12 @@ struct tangent_imp {
tangents::tangents(core * c) : common(c) {}
void tangents::tangent_lemma() {
if (!c().m_nla_settings.run_tangents()) {
TRACE("nla_solver", tout << "not generating tangent lemmas\n";);
return;
}
factorization bf(nullptr);
const monic* m;
if (c().find_bfc_to_refine(m, bf)) {
unsigned j = m->var();
tangent_imp i(point(val(bf[0]), val(bf[1])),
c().val(j),
j,
*m,
bf,
*this);
i.tangent_lemma_on_bf();
const monic* m = nullptr;
if (c().m_nla_settings.run_tangents() && c().find_bfc_to_refine(m, bf)) {
lpvar j = m->var();
tangent_imp tangent(point(val(bf[0]), val(bf[1])), c().val(j), *m, bf, *this);
tangent();
}
}