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eliminate basic variables from new rows

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2021-05-12 15:58:35 -07:00
parent 62b7719d5a
commit 0d776ecf88
4 changed files with 191 additions and 94 deletions
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57
src/math/polysat/fixplex.h
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@ -41,6 +41,14 @@ namespace polysat {
typedef typename matrix::row row;
typedef typename matrix::row_iterator row_iterator;
typedef typename matrix::col_iterator col_iterator;
struct var_eq {
var_t x, y;
row r1, r2;
var_eq(var_t x, var_t y, row const& r1, row const& r2):
x(x), y(y), r1(r1), r2(r2) {}
};
protected:
struct var_lt {
bool operator()(var_t v1, var_t v2) const { return v1 < v2; }
@ -73,9 +81,13 @@ namespace polysat {
m_is_base(false)
{}
var_info& operator&=(mod_interval<numeral> const& range) {
mod_interval<numeral>::operator=(range);
mod_interval<numeral>::operator=(range & *this);
return *this;
}
var_info& operator=(mod_interval<numeral> const& range) {
mod_interval<numeral>::operator=(range);
return *this;
}
};
struct row_info {
@ -85,12 +97,6 @@ namespace polysat {
numeral m_base_coeff;
};
struct var_eq {
var_t x, y;
row r1, r2;
var_eq(var_t x, var_t y, row const& r1, row const& r2):
x(x), y(y), r1(r1), r2(r2) {}
};
struct fix_entry {
var_t x;
@ -128,7 +134,7 @@ namespace polysat {
void set_bounds(var_t v, numeral const& lo, numeral const& hi);
void unset_bounds(var_t v) { m_vars[v].lo = m_vars[v].hi; }
void unset_bounds(var_t v) { m_vars[v].set_free(); }
var_t get_base_var(row const& r) const { return m_rows[r.id()].m_base; }
numeral const& lo(var_t var) const { return m_vars[var].lo; }
@ -136,9 +142,11 @@ namespace polysat {
numeral const& value(var_t var) const { return m_vars[var].m_value; }
void set_max_iterations(unsigned n) { m_max_iterations = n; }
unsigned get_num_vars() const { return m_vars.size(); }
void reset();
void propagate_bounds();
void propagate_eqs();
void reset();
void propagate_bounds();
void propagate_eqs();
vector<var_eq> const& var_eqs() const { return m_var_eqs; }
void reset_eqs() { m_var_eqs.reset(); }
lbool make_feasible();
row add_row(var_t base, unsigned num_vars, var_t const* vars, numeral const* coeffs);
std::ostream& display(std::ostream& out) const;
@ -149,14 +157,10 @@ namespace polysat {
void del_row(var_t base_var);
private:
void gauss_jordan();
void make_basic(var_t v, row const& r);
void update_value_core(var_t v, numeral const& delta);
void ensure_var(var_t v);
void ensure_var(var_t v);
var_t select_smallest_var() { return m_to_patch.empty()?null_var:m_to_patch.erase_min(); }
lbool make_var_feasible(var_t x_i);
@ -171,9 +175,11 @@ namespace polysat {
void new_bound(row const& r, var_t x, mod_interval<numeral> const& range);
void pivot(var_t x_i, var_t x_j, numeral const& b, numeral const& value);
numeral value2delta(var_t v, numeral const& new_value) const;
numeral value2error(var_t v, numeral const& new_value) const;
void update_value(var_t v, numeral const& delta);
bool can_pivot(var_t x_i, numeral const& new_value, numeral const& a_ij, var_t x_j);
bool has_minimal_trailing_zeros(var_t y, numeral const& b);
var_t select_pivot(var_t x_i, numeral const& new_value, numeral& out_b);
var_t select_pivot_core(var_t x, numeral const& new_value, numeral& out_b);
bool in_bounds(var_t v) const { return in_bounds(v, value(v)); }
bool in_bounds(var_t v, numeral const& b) const { return in_bounds(b, m_vars[v]); }
@ -206,17 +212,18 @@ namespace polysat {
void del_row(row const& r);
var_t select_pivot_blands(var_t x, numeral const& new_value, numeral& out_b);
bool can_improve(var_t x, numeral const& new_value, var_t y, numeral const& b);
#if 0
// TBD:
void move_to_bound(var_t x, bool to_lower) {}
var_t select_pivot(var_t x_i, bool is_below, numeral& out_a_ij) { throw nullptr; }
var_t select_pivot_blands(var_t x_i, bool is_below, numeral& out_a_ij) { throw nullptr; }
var_t pick_var_to_leave(var_t x_j, bool is_pos,
numeral& gain, numeral& new_a_ij, bool& inc) { throw nullptr; }
#endif
bool pivot_base_vars();
bool elim_base(var_t v);
bool eliminate_var(
row const& r_y,
row const& r_z,
numeral const& c,
unsigned tz_b,
numeral const& old_value_y);
};