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merging with the lp fork

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Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
This commit is contained in:
Lev Nachmanson 2017-05-10 16:53:25 -07:00
parent cf695ab876
commit b08f094620
44 changed files with 902 additions and 319 deletions
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1
src/shell/lp_frontend.cpp
View file

@ -80,7 +80,6 @@ void run_solver(lp_params & params, char const * mps_file_name) {
solver->settings().set_message_ostream(&std::cout);
solver->settings().report_frequency = params.rep_freq();
solver->settings().print_statistics = params.print_stats();
solver->settings().presolve_with_double_solver_for_lar = params.presolve_with_dbl();
solver->find_maximal_solution();
*(solver->settings().get_message_ostream()) << "status is " << lp_status_to_string(solver->get_status()) << std::endl;

29
src/smt/theory_lra.cpp
View file

@ -148,8 +148,6 @@ namespace smt {
arith_eq_adapter m_arith_eq_adapter;
vector<rational> m_columns;
int m_print_counter = 0;
// temporary values kept during internalization
struct internalize_state {
expr_ref_vector m_terms;
@ -287,7 +285,6 @@ namespace smt {
m_theory_var2var_index.reset();
m_solver->settings().set_resource_limit(m_resource_limit);
m_solver->settings().simplex_strategy() = static_cast<lean::simplex_strategy_enum>(lp.simplex_strategy());
m_solver->settings().presolve_with_double_solver_for_lar = lp.presolve_with_dbl();
reset_variable_values();
m_solver->settings().bound_propagation() = BP_NONE != propagation_mode();
m_solver->set_propagate_bounds_on_pivoted_rows_mode(lp.bprop_on_pivoted_rows());
@ -1985,7 +1982,6 @@ namespace smt {
typedef pair_hash<obj_hash<rational>, bool_hash> value_sort_pair_hash;
typedef map<value_sort_pair, theory_var, value_sort_pair_hash, default_eq<value_sort_pair> > value2var;
value2var m_fixed_var_table;
const lean::constraint_index null_index = static_cast<lean::constraint_index>(-1);
void propagate_eqs(lean::var_index vi, lean::constraint_index ci, lean::lconstraint_kind k, lp::bound& b) {
if (propagate_eqs()) {
@ -2029,10 +2025,10 @@ namespace smt {
lean::var_index ti = m_solver->adjust_term_index(vi);
auto& vec = is_lower ? m_lower_terms : m_upper_terms;
if (vec.size() <= ti) {
vec.resize(ti + 1, constraint_bound(null_index, rational()));
vec.resize(ti + 1, constraint_bound(UINT_MAX, rational()));
}
constraint_bound& b = vec[ti];
if (b.first == null_index || (is_lower? b.second < v : b.second > v)) {
if (b.first == UINT_MAX || (is_lower? b.second < v : b.second > v)) {
ctx().push_trail(vector_value_trail<context, constraint_bound>(vec, ti));
b.first = ci;
b.second = v;
@ -2052,7 +2048,7 @@ namespace smt {
rational val;
TRACE("arith", tout << vi << " " << v << "\n";);
if (v != null_theory_var && a.is_numeral(get_owner(v), val) && bound == val) {
ci = null_constraint_index;
ci = UINT_MAX;
return bound == val;
}
@ -2060,7 +2056,7 @@ namespace smt {
if (vec.size() > ti) {
constraint_bound& b = vec[ti];
ci = b.first;
return ci != null_index && bound == b.second;
return ci != UINT_MAX && bound == b.second;
}
else {
return false;
@ -2144,22 +2140,10 @@ namespace smt {
if (m_solver->A_r().row_count() > m_stats.m_max_rows)
m_stats.m_max_rows = m_solver->A_r().row_count();
TRACE("arith_verbose", display(tout););
bool print = false && m_print_counter++ % 1000 == 0;
stopwatch sw;
if (print) {
sw.start();
}
lean::lp_status status = m_solver->find_feasible_solution();
if (print) {
sw.stop();
}
m_stats.m_num_iterations = m_solver->settings().st().m_total_iterations;
m_stats.m_num_factorizations = m_solver->settings().st().m_num_factorizations;
m_stats.m_need_to_solve_inf = m_solver->settings().st().m_need_to_solve_inf;
if (print) {
IF_VERBOSE(0, verbose_stream() << status << " " << sw.get_seconds() << " " << m_stats.m_num_iterations << " " << m_print_counter << "\n";);
}
//m_stats.m_num_iterations_with_no_progress += m_solver->settings().st().m_iters_with_no_cost_growing;
switch (status) {
case lean::lp_status::INFEASIBLE:
@ -2182,10 +2166,11 @@ namespace smt {
literal_vector m_core;
svector<enode_pair> m_eqs;
vector<parameter> m_params;
lean::constraint_index const null_constraint_index = UINT_MAX;
// lean::constraint_index const null_constraint_index = UINT_MAX; // not sure what a correct fix is
void set_evidence(lean::constraint_index idx) {
if (idx == null_constraint_index) {
if (idx == UINT_MAX) {
return;
}
switch (m_constraint_sources[idx]) {

2
src/test/lp.cpp
View file

@ -1077,7 +1077,7 @@ bool get_double_from_args_parser(const char * option, argument_parser & args_par
void update_settings(argument_parser & args_parser, lp_settings& settings) {
unsigned n;
settings.m_simplex_strategy = simplex_strategy_enum::no_tableau;
settings.m_simplex_strategy = simplex_strategy_enum::lu;
if (get_int_from_args_parser("--rep_frq", args_parser, n))
settings.report_frequency = n;
else

9
src/test/smt_reader.h
View file

@ -56,10 +56,11 @@ namespace lean {
struct formula_constraint {
lconstraint_kind m_kind;
std::vector<std::pair<mpq, std::string>> m_coeffs;
mpq m_right_side = numeric_traits<mpq>::zero();
mpq m_right_side;
void add_pair(mpq c, std::string name) {
m_coeffs.push_back(make_pair(c, name));
}
formula_constraint() : m_right_side(numeric_traits<mpq>::zero()) {}
};
lisp_elem m_formula_lisp_elem;
@ -69,9 +70,11 @@ namespace lean {
std::string m_file_name;
std::ifstream m_file_stream;
std::string m_line;
bool m_is_OK = true;
unsigned m_line_number = 0;
bool m_is_OK;
unsigned m_line_number;
smt_reader(std::string file_name):
m_is_OK(true),
m_line_number(0),
m_file_name(file_name), m_file_stream(file_name) {
}

5
src/util/lp/binary_heap_priority_queue.h
View file

@ -16,8 +16,7 @@ class binary_heap_priority_queue {
// indexing for A starts from 1
vector<unsigned> m_heap; // keeps the elements of the queue
vector<int> m_heap_inverse; // o = m_heap[m_heap_inverse[o]]
unsigned m_heap_size = 0;
unsigned m_heap_size;
// is is the child place in heap
void swap_with_parent(unsigned i);
void put_at(unsigned i, unsigned h);
@ -29,7 +28,7 @@ public:
public:
void remove(unsigned o);
unsigned size() const { return m_heap_size; }
binary_heap_priority_queue(): m_heap(1) {} // the empty constructror
binary_heap_priority_queue(): m_heap(1), m_heap_size(0) {} // the empty constructror
// n is the initial queue capacity.
// The capacity will be enlarged two times automatically if needed
binary_heap_priority_queue(unsigned n);

3
src/util/lp/binary_heap_priority_queue.hpp
View file

@ -83,7 +83,8 @@ template <typename T> void binary_heap_priority_queue<T>::remove(unsigned o) {
template <typename T> binary_heap_priority_queue<T>::binary_heap_priority_queue(unsigned n) :
m_priorities(n),
m_heap(n + 1), // because the indexing for A starts from 1
m_heap_inverse(n, -1)
m_heap_inverse(n, -1),
m_heap_size(0)
{ }

4
src/util/lp/binary_heap_upair_queue.h
View file

@ -20,8 +20,8 @@ template <typename T>
class binary_heap_upair_queue {
binary_heap_priority_queue<T> m_q;
std::unordered_map<upair, unsigned> m_pairs_to_index;
vector<upair> m_pairs; // inverse to index
vector<unsigned> m_available_spots;
svector<upair> m_pairs; // inverse to index
svector<unsigned> m_available_spots;
public:
binary_heap_upair_queue(unsigned size);

8
src/util/lp/bound_analyzer_on_row.h
View file

@ -19,9 +19,9 @@ class bound_analyzer_on_row {
linear_combination_iterator<mpq> & m_it;
unsigned m_row_or_term_index;
int m_column_of_u = -1; // index of an unlimited from above monoid
int m_column_of_u; // index of an unlimited from above monoid
// -1 means that such a value is not found, -2 means that at least two of such monoids were found
int m_column_of_l = -1; // index of an unlimited from below monoid
int m_column_of_l; // index of an unlimited from below monoid
impq m_rs;
bound_propagator & m_bp;
public :
@ -36,7 +36,9 @@ public :
m_it(it),
m_row_or_term_index(row_or_term_index),
m_rs(rs),
m_bp(bp)
m_bp(bp),
m_column_of_u(-1),
m_column_of_l(-1)
{}

33
src/util/lp/column_info.h
View file

@ -15,16 +15,16 @@ inline bool is_valid(unsigned j) { return static_cast<int>(j) >= 0;}
template <typename T>
class column_info {
std::string m_name;
bool m_low_bound_is_set = false;
bool m_low_bound_is_strict = false;
bool m_upper_bound_is_set = false;
bool m_upper_bound_is_strict = false;
bool m_low_bound_is_set;
bool m_low_bound_is_strict;
bool m_upper_bound_is_set;
bool m_upper_bound_is_strict;
T m_low_bound;
T m_upper_bound;
T m_cost = numeric_traits<T>::zero();
T m_cost;
T m_fixed_value;
bool m_is_fixed = false;
unsigned m_column_index = static_cast<unsigned>(-1);
bool m_is_fixed;
unsigned m_column_index;
public:
bool operator==(const column_info & c) const {
return m_name == c.m_name &&
@ -44,9 +44,24 @@ public:
m_column_index = j;
}
// the default constructor
column_info() {}
column_info():
m_low_bound_is_set(false),
m_low_bound_is_strict(false),
m_upper_bound_is_set (false),
m_upper_bound_is_strict (false),
m_is_fixed(false),
m_cost(numeric_traits<T>::zero()),
m_column_index(static_cast<unsigned>(-1))
{}
column_info(unsigned column_index) : m_column_index(column_index) {
column_info(unsigned column_index) :
m_low_bound_is_set(false),
m_low_bound_is_strict(false),
m_upper_bound_is_set (false),
m_upper_bound_is_strict (false),
m_is_fixed(false),
m_cost(numeric_traits<T>::zero()),
m_column_index(column_index) {
}
column_info(const column_info & ci) {

44
src/util/lp/conversion_helper.h Normal file
View file

@ -0,0 +1,44 @@
/*
Copyright (c) 2013 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Lev Nachmanson
*/
#pragma once
namespace lean {
template <typename V>
struct conversion_helper {
static V get_low_bound(const column_info<mpq> & ci) {
return V(ci.get_low_bound(), ci.low_bound_is_strict()? 1 : 0);
}
static V get_upper_bound(const column_info<mpq> & ci) {
return V(ci.get_upper_bound(), ci.upper_bound_is_strict()? -1 : 0);
}
};
template<>
struct conversion_helper <double> {
static double conversion_helper <double>::get_upper_bound(const column_info<mpq> & ci) {
if (!ci.upper_bound_is_strict())
return ci.get_upper_bound().get_double();
double eps = 0.00001;
if (!ci.low_bound_is_set())
return ci.get_upper_bound().get_double() - eps;
eps = std::min((ci.get_upper_bound() - ci.get_low_bound()).get_double() / 1000, eps);
return ci.get_upper_bound().get_double() - eps;
}
static double get_low_bound(const column_info<mpq> & ci) {
if (!ci.low_bound_is_strict())
return ci.get_low_bound().get_double();
double eps = 0.00001;
if (!ci.upper_bound_is_set())
return ci.get_low_bound().get_double() + eps;
eps = std::min((ci.get_upper_bound() - ci.get_low_bound()).get_double() / 1000, eps);
return ci.get_low_bound().get_double() + eps;
}
};
}

11
src/util/lp/core_solver_pretty_printer.h
View file

@ -16,7 +16,6 @@ template <typename T, typename X> class lp_core_solver_base; // forward definiti
template <typename T, typename X>
class core_solver_pretty_printer {
std::ostream & m_out;
template<typename A> using vector = vector<A>;
typedef std::string string;
lp_core_solver_base<T, X> & m_core_solver;
vector<unsigned> m_column_widths;
@ -34,15 +33,15 @@ class core_solver_pretty_printer {
std::string m_cost_title;
std::string m_basis_heading_title;
std::string m_x_title;
std::string m_low_bounds_title = "low";
std::string m_upp_bounds_title = "upp";
std::string m_exact_norm_title = "exact cn";
std::string m_approx_norm_title = "approx cn";
std::string m_low_bounds_title;
std::string m_upp_bounds_title;
std::string m_exact_norm_title;
std::string m_approx_norm_title;
unsigned ncols() { return m_core_solver.m_A.column_count(); }
unsigned nrows() { return m_core_solver.m_A.row_count(); }
unsigned m_artificial_start = std::numeric_limits<unsigned>::max();
unsigned m_artificial_start;
indexed_vector<T> m_w_buff;
indexed_vector<T> m_ed_buff;
vector<T> m_exact_column_norms;

6
src/util/lp/core_solver_pretty_printer.hpp
View file

@ -23,6 +23,12 @@ core_solver_pretty_printer<T, X>::core_solver_pretty_printer(lp_core_solver_base
m_rs(ncols(), zero_of_type<X>()),
m_w_buff(core_solver.m_w),
m_ed_buff(core_solver.m_ed) {
m_low_bounds_title = "low";
m_upp_bounds_title = "upp";
m_exact_norm_title = "exact cn";
m_approx_norm_title = "approx cn";
m_artificial_start = std::numeric_limits<unsigned>::max();
m_column_widths.resize(core_solver.m_A.column_count(), 0),
init_m_A_and_signs();
init_costs();

573
src/util/lp/init_lar_solver.h Normal file
View file

@ -0,0 +1,573 @@
/*
Copyright (c) 2017 Microsoft Corporation
Author: Lev Nachmanson
*/
// here we are inside lean::lar_solver class
bool strategy_is_undecided() const {
return m_settings.simplex_strategy() == simplex_strategy_enum::undecided;
}
var_index add_var(unsigned ext_j) {
var_index i;
lean_assert (ext_j < m_terms_start_index);
if (ext_j >= m_terms_start_index)
throw 0; // todo : what is the right way to exit?
if (try_get_val(m_ext_vars_to_columns, ext_j, i)) {
return i;
}
lean_assert(m_vars_to_ul_pairs.size() == A_r().column_count());
i = A_r().column_count();
m_vars_to_ul_pairs.push_back (ul_pair(static_cast<unsigned>(-1)));
add_non_basic_var_to_core_fields(ext_j);
lean_assert(sizes_are_correct());
return i;
}
void register_new_ext_var_index(unsigned ext_v) {
lean_assert(!contains(m_ext_vars_to_columns, ext_v));
unsigned j = m_ext_vars_to_columns.size();
m_ext_vars_to_columns[ext_v] = j;
lean_assert(m_columns_to_ext_vars_or_term_indices.size() == j);
m_columns_to_ext_vars_or_term_indices.push_back(ext_v);
}
void add_non_basic_var_to_core_fields(unsigned ext_j) {
register_new_ext_var_index(ext_j);
m_mpq_lar_core_solver.m_column_types.push_back(column_type::free_column);
m_columns_with_changed_bound.increase_size_by_one();
add_new_var_to_core_fields_for_mpq(false);
if (use_lu())
add_new_var_to_core_fields_for_doubles(false);
}
void add_new_var_to_core_fields_for_doubles(bool register_in_basis) {
unsigned j = A_d().column_count();
A_d().add_column();
lean_assert(m_mpq_lar_core_solver.m_d_x.size() == j);
// lean_assert(m_mpq_lar_core_solver.m_d_low_bounds.size() == j && m_mpq_lar_core_solver.m_d_upper_bounds.size() == j); // restore later
m_mpq_lar_core_solver.m_d_x.resize(j + 1 );
m_mpq_lar_core_solver.m_d_low_bounds.resize(j + 1);
m_mpq_lar_core_solver.m_d_upper_bounds.resize(j + 1);
lean_assert(m_mpq_lar_core_solver.m_d_heading.size() == j); // as A().column_count() on the entry to the method
if (register_in_basis) {
A_d().add_row();
m_mpq_lar_core_solver.m_d_heading.push_back(m_mpq_lar_core_solver.m_d_basis.size());
m_mpq_lar_core_solver.m_d_basis.push_back(j);
}else {
m_mpq_lar_core_solver.m_d_heading.push_back(- static_cast<int>(m_mpq_lar_core_solver.m_d_nbasis.size()) - 1);
m_mpq_lar_core_solver.m_d_nbasis.push_back(j);
}
}
void add_new_var_to_core_fields_for_mpq(bool register_in_basis) {
unsigned j = A_r().column_count();
A_r().add_column();
lean_assert(m_mpq_lar_core_solver.m_r_x.size() == j);
// lean_assert(m_mpq_lar_core_solver.m_r_low_bounds.size() == j && m_mpq_lar_core_solver.m_r_upper_bounds.size() == j); // restore later
m_mpq_lar_core_solver.m_r_x.resize(j + 1);
m_mpq_lar_core_solver.m_r_low_bounds.increase_size_by_one();
m_mpq_lar_core_solver.m_r_upper_bounds.increase_size_by_one();
m_mpq_lar_core_solver.m_r_solver.m_inf_set.increase_size_by_one();
m_mpq_lar_core_solver.m_r_solver.m_costs.resize(j + 1);
m_mpq_lar_core_solver.m_r_solver.m_d.resize(j + 1);
lean_assert(m_mpq_lar_core_solver.m_r_heading.size() == j); // as A().column_count() on the entry to the method
if (register_in_basis) {
A_r().add_row();
m_mpq_lar_core_solver.m_r_heading.push_back(m_mpq_lar_core_solver.m_r_basis.size());
m_mpq_lar_core_solver.m_r_basis.push_back(j);
if (m_settings.bound_propagation())
m_rows_with_changed_bounds.insert(A_r().row_count() - 1);
} else {
m_mpq_lar_core_solver.m_r_heading.push_back(- static_cast<int>(m_mpq_lar_core_solver.m_r_nbasis.size()) - 1);
m_mpq_lar_core_solver.m_r_nbasis.push_back(j);
}
}
var_index add_term_undecided(const vector<std::pair<mpq, var_index>> & coeffs,
const mpq &m_v) {
m_terms.push_back(new lar_term(coeffs, m_v));
m_orig_terms.push_back(new lar_term(coeffs, m_v));
return m_terms_start_index + m_terms.size() - 1;
}
// terms
var_index add_term(const vector<std::pair<mpq, var_index>> & coeffs,
const mpq &m_v) {
if (strategy_is_undecided())
return add_term_undecided(coeffs, m_v);
m_terms.push_back(new lar_term(coeffs, m_v));
m_orig_terms.push_back(new lar_term(coeffs, m_v));
unsigned adjusted_term_index = m_terms.size() - 1;
var_index ret = m_terms_start_index + adjusted_term_index;
if (use_tableau() && !coeffs.empty()) {
add_row_for_term(m_orig_terms.back(), ret);
if (m_settings.bound_propagation())
m_rows_with_changed_bounds.insert(A_r().row_count() - 1);
}
lean_assert(m_ext_vars_to_columns.size() == A_r().column_count());
return ret;
}
void add_row_for_term(const lar_term * term, unsigned term_ext_index) {
lean_assert(sizes_are_correct());
add_row_from_term_no_constraint(term, term_ext_index);
lean_assert(sizes_are_correct());
}
void add_row_from_term_no_constraint(const lar_term * term, unsigned term_ext_index) {
register_new_ext_var_index(term_ext_index);
// j will be a new variable
unsigned j = A_r().column_count();
ul_pair ul(j);
m_vars_to_ul_pairs.push_back(ul);
add_basic_var_to_core_fields();
if (use_tableau()) {
auto it = iterator_on_term_with_basis_var(*term, j);
A_r().fill_last_row_with_pivoting(it,
m_mpq_lar_core_solver.m_r_solver.m_basis_heading);
m_mpq_lar_core_solver.m_r_solver.m_b.resize(A_r().column_count(), zero_of_type<mpq>());
} else {
fill_last_row_of_A_r(A_r(), term);
}
m_mpq_lar_core_solver.m_r_x[j] = get_basic_var_value_from_row_directly(A_r().row_count() - 1);
if (use_lu())
fill_last_row_of_A_d(A_d(), term);
}
void add_basic_var_to_core_fields() {
bool use_lu = m_mpq_lar_core_solver.need_to_presolve_with_double_solver();
lean_assert(!use_lu || A_r().column_count() == A_d().column_count());
m_mpq_lar_core_solver.m_column_types.push_back(column_type::free_column);
m_columns_with_changed_bound.increase_size_by_one();
m_rows_with_changed_bounds.increase_size_by_one();
add_new_var_to_core_fields_for_mpq(true);
if (use_lu)
add_new_var_to_core_fields_for_doubles(true);
}
constraint_index add_var_bound(var_index j, lconstraint_kind kind, const mpq & right_side) {
constraint_index ci = m_constraints.size();
if (!is_term(j)) { // j is a var
auto vc = new lar_var_constraint(j, kind, right_side);
m_constraints.push_back(vc);
update_column_type_and_bound(j, kind, right_side, ci);
} else {
add_var_bound_on_constraint_for_term(j, kind, right_side, ci);
}
lean_assert(sizes_are_correct());
return ci;
}
void update_column_type_and_bound(var_index j, lconstraint_kind kind, const mpq & right_side, constraint_index constr_index) {
switch(m_mpq_lar_core_solver.m_column_types[j]) {
case column_type::free_column:
update_free_column_type_and_bound(j, kind, right_side, constr_index);
break;
case column_type::boxed:
update_boxed_column_type_and_bound(j, kind, right_side, constr_index);
break;
case column_type::low_bound:
update_low_bound_column_type_and_bound(j, kind, right_side, constr_index);
break;
case column_type::upper_bound:
update_upper_bound_column_type_and_bound(j, kind, right_side, constr_index);
break;
case column_type::fixed:
update_fixed_column_type_and_bound(j, kind, right_side, constr_index);
break;
default:
lean_assert(false); // cannot be here
}
}
void add_var_bound_on_constraint_for_term(var_index j, lconstraint_kind kind, const mpq & right_side, constraint_index ci) {
lean_assert(is_term(j));
unsigned adjusted_term_index = adjust_term_index(j);
unsigned term_j;
if (try_get_val(m_ext_vars_to_columns, j, term_j)) {
mpq rs = right_side - m_orig_terms[adjusted_term_index]->m_v;
m_constraints.push_back(new lar_term_constraint(m_orig_terms[adjusted_term_index], kind, right_side));
update_column_type_and_bound(term_j, kind, rs, ci);
}
else {
add_constraint_from_term_and_create_new_column_row(j, m_orig_terms[adjusted_term_index], kind, right_side);
}
}
void add_constraint_from_term_and_create_new_column_row(unsigned term_j, const lar_term* term,
lconstraint_kind kind, const mpq & right_side) {
add_row_from_term_no_constraint(term, term_j);
unsigned j = A_r().column_count() - 1;
update_column_type_and_bound(j, kind, right_side - term->m_v, m_constraints.size());
m_constraints.push_back(new lar_term_constraint(term, kind, right_side));
lean_assert(A_r().column_count() == m_mpq_lar_core_solver.m_r_solver.m_costs.size());
}
void decide_on_strategy_and_adjust_initial_state() {
lean_assert(strategy_is_undecided());
if (m_vars_to_ul_pairs.size() > m_settings.column_number_threshold_for_using_lu_in_lar_solver) {
m_settings.simplex_strategy() = simplex_strategy_enum::lu;
} else {
m_settings.simplex_strategy() = simplex_strategy_enum::tableau_rows; // todo: when to switch to tableau_costs?
}
adjust_initial_state();
}
void adjust_initial_state() {
switch (m_settings.simplex_strategy()) {
case simplex_strategy_enum::lu:
adjust_initial_state_for_lu();
break;
case simplex_strategy_enum::tableau_rows:
adjust_initial_state_for_tableau_rows();
break;
case simplex_strategy_enum::tableau_costs:
lean_assert(false); // not implemented
}
}
void adjust_initial_state_for_lu() {
copy_from_mpq_matrix(A_d());
unsigned n = A_d().column_count();
m_mpq_lar_core_solver.m_d_x.resize(n);
m_mpq_lar_core_solver.m_d_low_bounds.resize(n);
m_mpq_lar_core_solver.m_d_upper_bounds.resize(n);
m_mpq_lar_core_solver.m_d_heading = m_mpq_lar_core_solver.m_r_heading;
m_mpq_lar_core_solver.m_d_basis = m_mpq_lar_core_solver.m_r_basis;
/*
unsigned j = A_d().column_count();
A_d().add_column();
lean_assert(m_mpq_lar_core_solver.m_d_x.size() == j);
// lean_assert(m_mpq_lar_core_solver.m_d_low_bounds.size() == j && m_mpq_lar_core_solver.m_d_upper_bounds.size() == j); // restore later
m_mpq_lar_core_solver.m_d_x.resize(j + 1 );
m_mpq_lar_core_solver.m_d_low_bounds.resize(j + 1);
m_mpq_lar_core_solver.m_d_upper_bounds.resize(j + 1);
lean_assert(m_mpq_lar_core_solver.m_d_heading.size() == j); // as A().column_count() on the entry to the method
if (register_in_basis) {
A_d().add_row();
m_mpq_lar_core_solver.m_d_heading.push_back(m_mpq_lar_core_solver.m_d_basis.size());
m_mpq_lar_core_solver.m_d_basis.push_back(j);
}else {
m_mpq_lar_core_solver.m_d_heading.push_back(- static_cast<int>(m_mpq_lar_core_solver.m_d_nbasis.size()) - 1);
m_mpq_lar_core_solver.m_d_nbasis.push_back(j);
}*/
}
void adjust_initial_state_for_tableau_rows() {
for (unsigned j = 0; j < m_terms.size(); j++) {
if (contains(m_ext_vars_to_columns, j + m_terms_start_index))
continue;
add_row_from_term_no_constraint(m_terms[j], j + m_terms_start_index);
}
}
// this fills the last row of A_d and sets the basis column: -1 in the last column of the row
void fill_last_row_of_A_d(static_matrix<double, double> & A, const lar_term* ls) {
lean_assert(A.row_count() > 0);
lean_assert(A.column_count() > 0);
unsigned last_row = A.row_count() - 1;
lean_assert(A.m_rows[last_row].empty());
for (auto & t : ls->m_coeffs) {
lean_assert(!is_zero(t.second));
var_index j = t.first;
A.set(last_row, j, - t.second.get_double());
}
unsigned basis_j = A.column_count() - 1;
A.set(last_row, basis_j, - 1 );
}
void update_free_column_type_and_bound(var_index j, lconstraint_kind kind, const mpq & right_side, constraint_index constr_ind) {
mpq y_of_bound(0);
switch (kind) {
case LT:
y_of_bound = -1;
case LE:
m_mpq_lar_core_solver.m_column_types[j] = column_type::upper_bound;
lean_assert(m_mpq_lar_core_solver.m_column_types()[j] == column_type::upper_bound);
lean_assert(m_mpq_lar_core_solver.m_r_upper_bounds.size() > j);
{
auto up = numeric_pair<mpq>(right_side, y_of_bound);
m_mpq_lar_core_solver.m_r_upper_bounds[j] = up;
}
set_upper_bound_witness(j, constr_ind);
break;
case GT:
y_of_bound = 1;
case GE:
m_mpq_lar_core_solver.m_column_types[j] = column_type::low_bound;
lean_assert(m_mpq_lar_core_solver.m_r_upper_bounds.size() > j);
{
auto low = numeric_pair<mpq>(right_side, y_of_bound);
m_mpq_lar_core_solver.m_r_low_bounds[j] = low;
}
set_low_bound_witness(j, constr_ind);
break;
case EQ:
m_mpq_lar_core_solver.m_column_types[j] = column_type::fixed;
m_mpq_lar_core_solver.m_r_low_bounds[j] = m_mpq_lar_core_solver.m_r_upper_bounds[j] = numeric_pair<mpq>(right_side, zero_of_type<mpq>());
set_upper_bound_witness(j, constr_ind);
set_low_bound_witness(j, constr_ind);
break;
default:
lean_unreachable();
}
m_columns_with_changed_bound.insert(j);
}
void update_upper_bound_column_type_and_bound(var_index j, lconstraint_kind kind, const mpq & right_side, constraint_index ci) {
lean_assert(m_mpq_lar_core_solver.m_column_types()[j] == column_type::upper_bound);
mpq y_of_bound(0);
switch (kind) {
case LT:
y_of_bound = -1;
case LE:
{
auto up = numeric_pair<mpq>(right_side, y_of_bound);
if (up < m_mpq_lar_core_solver.m_r_upper_bounds()[j]) {
m_mpq_lar_core_solver.m_r_upper_bounds[j] = up;
set_upper_bound_witness(j, ci);
m_columns_with_changed_bound.insert(j);
}
}
break;
case GT:
y_of_bound = 1;
case GE:
m_mpq_lar_core_solver.m_column_types[j] = column_type::boxed;
{
auto low = numeric_pair<mpq>(right_side, y_of_bound);
m_mpq_lar_core_solver.m_r_low_bounds[j] = low;
set_low_bound_witness(j, ci);
m_columns_with_changed_bound.insert(j);
if (low > m_mpq_lar_core_solver.m_r_upper_bounds[j]) {
m_status = INFEASIBLE;
m_infeasible_column_index = j;
} else {
m_mpq_lar_core_solver.m_column_types[j] = m_mpq_lar_core_solver.m_r_low_bounds()[j] < m_mpq_lar_core_solver.m_r_upper_bounds()[j]? column_type::boxed : column_type::fixed;
}
}
break;
case EQ:
{
auto v = numeric_pair<mpq>(right_side, zero_of_type<mpq>());
if (v > m_mpq_lar_core_solver.m_r_upper_bounds[j]) {
m_status = INFEASIBLE;
set_low_bound_witness(j, ci);
m_infeasible_column_index = j;
} else {
m_mpq_lar_core_solver.m_r_low_bounds[j] = m_mpq_lar_core_solver.m_r_upper_bounds[j] = v;
m_columns_with_changed_bound.insert(j);
set_low_bound_witness(j, ci);
set_upper_bound_witness(j, ci);
m_mpq_lar_core_solver.m_column_types[j] = column_type::fixed;
}
break;
}
break;
default:
lean_unreachable();
}
}
void update_boxed_column_type_and_bound(var_index j, lconstraint_kind kind, const mpq & right_side, constraint_index ci) {
lean_assert(m_status == INFEASIBLE || (m_mpq_lar_core_solver.m_column_types()[j] == column_type::boxed && m_mpq_lar_core_solver.m_r_low_bounds()[j] < m_mpq_lar_core_solver.m_r_upper_bounds()[j]));
mpq y_of_bound(0);
switch (kind) {
case LT:
y_of_bound = -1;
case LE:
{
auto up = numeric_pair<mpq>(right_side, y_of_bound);
if (up < m_mpq_lar_core_solver.m_r_upper_bounds[j]) {
m_mpq_lar_core_solver.m_r_upper_bounds[j] = up;
set_upper_bound_witness(j, ci);
m_columns_with_changed_bound.insert(j);
}
if (up < m_mpq_lar_core_solver.m_r_low_bounds[j]) {
m_status = INFEASIBLE;
lean_assert(false);
m_infeasible_column_index = j;
} else {
if (m_mpq_lar_core_solver.m_r_low_bounds()[j] == m_mpq_lar_core_solver.m_r_upper_bounds()[j])
m_mpq_lar_core_solver.m_column_types[j] = column_type::fixed;
}
}
break;
case GT:
y_of_bound = 1;
case GE:
{
auto low = numeric_pair<mpq>(right_side, y_of_bound);
if (low > m_mpq_lar_core_solver.m_r_low_bounds[j]) {
m_mpq_lar_core_solver.m_r_low_bounds[j] = low;
m_columns_with_changed_bound.insert(j);
set_low_bound_witness(j, ci);
}
if (low > m_mpq_lar_core_solver.m_r_upper_bounds[j]) {
m_status = INFEASIBLE;
m_infeasible_column_index = j;
} else if ( low == m_mpq_lar_core_solver.m_r_upper_bounds[j]) {
m_mpq_lar_core_solver.m_column_types[j] = column_type::fixed;
}
}
break;
case EQ:
{
auto v = numeric_pair<mpq>(right_side, zero_of_type<mpq>());
if (v < m_mpq_lar_core_solver.m_r_low_bounds[j]) {
m_status = INFEASIBLE;
m_infeasible_column_index = j;
set_upper_bound_witness(j, ci);
} else if (v > m_mpq_lar_core_solver.m_r_upper_bounds[j]) {
m_status = INFEASIBLE;
m_infeasible_column_index = j;
set_low_bound_witness(j, ci);
} else {
m_mpq_lar_core_solver.m_r_low_bounds[j] = m_mpq_lar_core_solver.m_r_upper_bounds[j] = v;
set_low_bound_witness(j, ci);
set_upper_bound_witness(j, ci);
m_mpq_lar_core_solver.m_column_types[j] = column_type::fixed;
m_columns_with_changed_bound.insert(j);
}
break;
}
default:
lean_unreachable();
}
}
void update_low_bound_column_type_and_bound(var_index j, lconstraint_kind kind, const mpq & right_side, constraint_index ci) {
lean_assert(m_mpq_lar_core_solver.m_column_types()[j] == column_type::low_bound);
mpq y_of_bound(0);
switch (kind) {
case LT:
y_of_bound = -1;
case LE:
{
auto up = numeric_pair<mpq>(right_side, y_of_bound);
m_mpq_lar_core_solver.m_r_upper_bounds[j] = up;
set_upper_bound_witness(j, ci);
m_columns_with_changed_bound.insert(j);
if (up < m_mpq_lar_core_solver.m_r_low_bounds[j]) {
m_status = INFEASIBLE;
m_infeasible_column_index = j;
} else {
m_mpq_lar_core_solver.m_column_types[j] = m_mpq_lar_core_solver.m_r_low_bounds()[j] < m_mpq_lar_core_solver.m_r_upper_bounds()[j]? column_type::boxed : column_type::fixed;
}
}
break;
case GT:
y_of_bound = 1;
case GE:
{
auto low = numeric_pair<mpq>(right_side, y_of_bound);
if (low > m_mpq_lar_core_solver.m_r_low_bounds[j]) {
m_mpq_lar_core_solver.m_r_low_bounds[j] = low;
m_columns_with_changed_bound.insert(j);
set_low_bound_witness(j, ci);
}
}
break;
case EQ:
{
auto v = numeric_pair<mpq>(right_side, zero_of_type<mpq>());
if (v < m_mpq_lar_core_solver.m_r_low_bounds[j]) {
m_status = INFEASIBLE;
m_infeasible_column_index = j;
set_upper_bound_witness(j, ci);
} else {
m_mpq_lar_core_solver.m_r_low_bounds[j] = m_mpq_lar_core_solver.m_r_upper_bounds[j] = v;
set_low_bound_witness(j, ci);
set_upper_bound_witness(j, ci);
m_mpq_lar_core_solver.m_column_types[j] = column_type::fixed;
}
m_columns_with_changed_bound.insert(j);
break;
}
default:
lean_unreachable();
}
}
void update_fixed_column_type_and_bound(var_index j, lconstraint_kind kind, const mpq & right_side, constraint_index ci) {
lean_assert(m_status == INFEASIBLE || (m_mpq_lar_core_solver.m_column_types()[j] == column_type::fixed && m_mpq_lar_core_solver.m_r_low_bounds()[j] == m_mpq_lar_core_solver.m_r_upper_bounds()[j]));
lean_assert(m_status == INFEASIBLE || (m_mpq_lar_core_solver.m_r_low_bounds()[j].y.is_zero() && m_mpq_lar_core_solver.m_r_upper_bounds()[j].y.is_zero()));
auto v = numeric_pair<mpq>(right_side, mpq(0));
mpq y_of_bound(0);
switch (kind) {
case LT:
if (v <= m_mpq_lar_core_solver.m_r_low_bounds[j]) {
m_status = INFEASIBLE;
m_infeasible_column_index = j;
set_upper_bound_witness(j, ci);
}
break;
case LE:
{
if (v < m_mpq_lar_core_solver.m_r_low_bounds[j]) {
m_status = INFEASIBLE;
m_infeasible_column_index = j;
set_upper_bound_witness(j, ci);
}
}
break;
case GT:
{
if (v >= m_mpq_lar_core_solver.m_r_upper_bounds[j]) {
m_status = INFEASIBLE;
m_infeasible_column_index =j;
set_low_bound_witness(j, ci);
}
}
break;
case GE:
{
if (v > m_mpq_lar_core_solver.m_r_upper_bounds[j]) {
m_status = INFEASIBLE;
m_infeasible_column_index = j;
set_low_bound_witness(j, ci);
}
}
break;
case EQ:
{
if (v < m_mpq_lar_core_solver.m_r_low_bounds[j]) {
m_status = INFEASIBLE;
m_infeasible_column_index = j;
set_upper_bound_witness(j, ci);
} else if (v > m_mpq_lar_core_solver.m_r_upper_bounds[j]) {
m_status = INFEASIBLE;
m_infeasible_column_index = j;
set_low_bound_witness(j, ci);
}
break;
}
default:
lean_unreachable();
}
}

2
src/util/lp/iterator_on_column.h
View file

@ -11,7 +11,7 @@ template <typename T, typename X>
struct iterator_on_column:linear_combination_iterator<T> {
const vector<column_cell>& m_column; // the offset in term coeffs
const static_matrix<T, X> & m_A;
int m_i = -1; // the initial offset in the column
int m_i; // the initial offset in the column
unsigned size() const { return m_column.size(); }
iterator_on_column(const vector<column_cell>& column, const static_matrix<T,X> & A) // the offset in term coeffs
:

7
src/util/lp/iterator_on_indexed_vector.h
View file

@ -8,8 +8,11 @@ namespace lean {
template <typename T>
struct iterator_on_indexed_vector:linear_combination_iterator<T> {
const indexed_vector<T> & m_v;
unsigned m_offset = 0;
iterator_on_indexed_vector(const indexed_vector<T> & v) : m_v(v){}
unsigned m_offset;
iterator_on_indexed_vector(const indexed_vector<T> & v) :
m_v(v),
m_offset(0)
{}
unsigned size() const { return m_v.m_index.size(); }
bool next(T & a, unsigned & i) {
if (m_offset >= m_v.m_index.size())

6
src/util/lp/iterator_on_pivot_row.h
View file

@ -7,12 +7,14 @@
namespace lean {
template <typename T>
struct iterator_on_pivot_row:linear_combination_iterator<T> {
bool m_basis_returned = false;
bool m_basis_returned;
const indexed_vector<T> & m_v;
unsigned m_basis_j;
iterator_on_indexed_vector<T> m_it;
unsigned size() const { return m_it.size(); }
iterator_on_pivot_row(const indexed_vector<T> & v, unsigned basis_j) : m_v(v), m_basis_j(basis_j), m_it(v) {}
iterator_on_pivot_row(const indexed_vector<T> & v, unsigned basis_j) :
m_basis_returned(false),
m_v(v), m_basis_j(basis_j), m_it(v) {}
bool next(T & a, unsigned & i) {
if (m_basis_returned == false) {
m_basis_returned = true;

4
src/util/lp/iterator_on_row.h
View file

@ -8,8 +8,8 @@ namespace lean {
template <typename T>
struct iterator_on_row:linear_combination_iterator<T> {
const vector<row_cell<T>> & m_row;
unsigned m_i= 0; // offset
iterator_on_row(const vector<row_cell<T>> & row) : m_row(row)
unsigned m_i; // offset
iterator_on_row(const vector<row_cell<T>> & row) : m_row(row), m_i(0)
{}
unsigned size() const { return m_row.size(); }
bool next(T & a, unsigned & i) {

3
src/util/lp/iterator_on_term_with_basis_var.h
View file

@ -9,11 +9,12 @@
namespace lean {
struct iterator_on_term_with_basis_var:linear_combination_iterator<mpq> {
std::unordered_map<unsigned, mpq>::const_iterator m_i; // the offset in term coeffs
bool m_term_j_returned = false;
bool m_term_j_returned;
const lar_term & m_term;
unsigned m_term_j;
unsigned size() const {return static_cast<unsigned>(m_term.m_coeffs.size() + 1);}
iterator_on_term_with_basis_var(const lar_term & t, unsigned term_j) :
m_term_j_returned(false),
m_i(t.m_coeffs.begin()),
m_term(t),
m_term_j(term_j) {}

2
src/util/lp/lar_core_solver.h
View file

@ -25,7 +25,7 @@ class lar_core_solver {
// to grow and is set to -1 otherwise
int m_sign_of_entering_delta;
vector<std::pair<mpq, unsigned>> m_infeasible_linear_combination;
int m_infeasible_sum_sign = 0; // todo: get rid of this field
int m_infeasible_sum_sign; // todo: get rid of this field
vector<numeric_pair<mpq>> m_right_sides_dummy;
vector<mpq> m_costs_dummy;
vector<double> m_d_right_sides_dummy;

1
src/util/lp/lar_core_solver.hpp
View file

@ -15,6 +15,7 @@ lar_core_solver::lar_core_solver(
lp_settings & settings,
const column_namer & column_names
):
m_infeasible_sum_sign(0),
m_r_solver(m_r_A,
m_right_sides_dummy,
m_r_x,

15
src/util/lp/lar_solver.h
View file

@ -35,7 +35,7 @@ namespace lean {
class lar_solver : public column_namer {
//////////////////// fields //////////////////////////
lp_settings m_settings;
stacked_value<lp_status> m_status = OPTIMAL;
stacked_value<lp_status> m_status;
stacked_value<simplex_strategy_enum> m_simplex_strategy;
std::unordered_map<unsigned, var_index> m_ext_vars_to_columns;
vector<unsigned> m_columns_to_ext_vars_or_term_indices;
@ -46,13 +46,13 @@ class lar_solver : public column_namer {
int_set m_columns_with_changed_bound;
int_set m_rows_with_changed_bounds;
int_set m_basic_columns_with_changed_cost;
stacked_value<int> m_infeasible_column_index = -1; // such can be found at the initialization step
stacked_value<int> m_infeasible_column_index; // such can be found at the initialization step
stacked_value<unsigned> m_term_count;
vector<lar_term*> m_terms;
vector<lar_term*> m_orig_terms;
const var_index m_terms_start_index = 1000000;
const var_index m_terms_start_index;
indexed_vector<mpq> m_column_buffer;
std::function<column_type (unsigned)> m_column_type_function = [this] (unsigned j) {return m_mpq_lar_core_solver.m_column_types()[j];};
std::function<column_type (unsigned)> m_column_type_function;
public:
lar_core_solver m_mpq_lar_core_solver;
unsigned constraint_count() const {
@ -83,7 +83,12 @@ public:
lar_solver() : m_mpq_lar_core_solver(
m_settings,
*this
) {}
),
m_status(OPTIMAL),
m_infeasible_column_index(-1),
m_terms_start_index(1000000),
m_column_type_function ([this] (unsigned j) {return m_mpq_lar_core_solver.m_column_types()[j];})
{}
void set_propagate_bounds_on_pivoted_rows_mode(bool v) {
m_mpq_lar_core_solver.m_r_solver.m_pivoted_rows = v? (& m_rows_with_changed_bounds) : nullptr;

7
src/util/lp/linear_combination_iterator.h
View file

@ -16,7 +16,7 @@ struct linear_combination_iterator {
template <typename T>
struct linear_combination_iterator_on_vector : linear_combination_iterator<T> {
vector<std::pair<T, unsigned>> & m_vector;
int m_offset = 0;
int m_offset;
bool next(T & a, unsigned & i) {
if(m_offset >= m_vector.size())
return false;
@ -40,7 +40,10 @@ struct linear_combination_iterator_on_vector : linear_combination_iterator<T> {
linear_combination_iterator<T> * clone() {
return new linear_combination_iterator_on_vector(m_vector);
}
linear_combination_iterator_on_vector(vector<std::pair<T, unsigned>> & vec): m_vector(vec) {}
linear_combination_iterator_on_vector(vector<std::pair<T, unsigned>> & vec):
m_vector(vec),
m_offset(0)
{}
unsigned size() const { return m_vector.size(); }
};

16
src/util/lp/lp_core_solver_base.h
View file

@ -17,7 +17,7 @@ namespace lean {
template <typename T, typename X> // X represents the type of the x variable and the bounds
class lp_core_solver_base {
unsigned m_total_iterations = 0;
unsigned m_total_iterations;
unsigned inc_total_iterations() { ++m_settings.st().m_total_iterations; return m_total_iterations++; }
private:
lp_status m_status;
@ -25,7 +25,7 @@ public:
bool current_x_is_feasible() const { return m_inf_set.size() == 0; }
bool current_x_is_infeasible() const { return m_inf_set.size() != 0; }
int_set m_inf_set;
bool m_using_infeas_costs = false;
bool m_using_infeas_costs;
vector<unsigned> m_columns_nz; // m_columns_nz[i] keeps an approximate value of non zeroes the i-th column
@ -42,23 +42,23 @@ public:
lp_settings & m_settings;
vector<T> m_y; // the buffer for yB = cb
// a device that is able to solve Bx=c, xB=d, and change the basis
lu<T, X> * m_factorization = nullptr;
lu<T, X> * m_factorization;
const column_namer & m_column_names;
indexed_vector<T> m_w; // the vector featuring in 24.3 of the Chvatal book
vector<T> m_d; // the vector of reduced costs
indexed_vector<T> m_ed; // the solution of B*m_ed = a
unsigned m_iters_with_no_cost_growing = 0;
unsigned m_iters_with_no_cost_growing;
const vector<column_type> & m_column_types;
const vector<X> & m_low_bounds;
const vector<X> & m_upper_bounds;
vector<T> m_column_norms; // the approximate squares of column norms that help choosing a profitable column
vector<X> m_copy_of_xB;
unsigned m_basis_sort_counter = 0;
unsigned m_basis_sort_counter;
vector<T> m_steepest_edge_coefficients;
vector<unsigned> m_trace_of_basis_change_vector; // the even positions are entering, the odd positions are leaving
bool m_tracing_basis_changes = false;
int_set* m_pivoted_rows = nullptr;
bool m_look_for_feasible_solution_only = false;
bool m_tracing_basis_changes;
int_set* m_pivoted_rows;
bool m_look_for_feasible_solution_only;
void start_tracing_basis_changes() {
m_trace_of_basis_change_vector.resize(0);
m_tracing_basis_changes = true;

9
src/util/lp/lp_core_solver_base.hpp
View file

@ -45,7 +45,14 @@ lp_core_solver_base(static_matrix<T, X> & A,
m_upper_bounds(upper_bound_values),
m_column_norms(m_n()),
m_copy_of_xB(m_m()),
m_steepest_edge_coefficients(A.column_count()) {
m_steepest_edge_coefficients(A.column_count()),
m_total_iterations(0),
m_using_infeas_costs(false),
m_iters_with_no_cost_growing(0),
m_basis_sort_counter(0),
m_tracing_basis_changes(false),
m_pivoted_rows(nullptr),
m_look_for_feasible_solution_only(false) {
lean_assert(bounds_for_boxed_are_set_correctly());
init();
init_basis_heading_and_non_basic_columns_vector();

3
src/util/lp/lp_dual_simplex.h
View file

@ -11,7 +11,7 @@ namespace lean {
template <typename T, typename X>
class lp_dual_simplex: public lp_solver<T, X> {
lp_dual_core_solver<T, X> * m_core_solver = nullptr;
lp_dual_core_solver<T, X> * m_core_solver;
vector<T> m_b_copy;
vector<T> m_low_bounds; // We don't have a convention here that all low bounds are zeros. At least it does not hold for the first stage solver
vector<column_type> m_column_types_of_core_solver;
@ -24,6 +24,7 @@ public:
}
}
lp_dual_simplex() : m_core_solver(nullptr) {}
void decide_on_status_after_stage1();

6
src/util/lp/lp_primal_core_solver.h
View file

@ -38,13 +38,13 @@ public:
vector<breakpoint<X>> m_breakpoints;
binary_heap_priority_queue<X> m_breakpoint_indices_queue;
indexed_vector<T> m_beta; // see Swietanowski working vector beta for column norms
T m_epsilon_of_reduced_cost = T(1)/T(10000000);
T m_epsilon_of_reduced_cost;
vector<T> m_costs_backup;
T m_converted_harris_eps;
unsigned m_inf_row_index_for_tableau;
bool m_bland_mode_tableau;
int_set m_left_basis_tableau;
unsigned m_bland_mode_threshold = 1000;
unsigned m_bland_mode_threshold;
unsigned m_left_basis_repeated;
vector<unsigned> m_leaving_candidates;
// T m_converted_harris_eps = convert_struct<T, double>::convert(this->m_settings.harris_feasibility_tolerance);
@ -905,6 +905,8 @@ public:
column_type_array,
low_bound_values,
upper_bound_values),
m_epsilon_of_reduced_cost(T(1)/T(10000000)),
m_bland_mode_threshold(1000),
m_beta(A.row_count()) {
if (!(numeric_traits<T>::precise())) {

4
src/util/lp/lp_primal_simplex.h
View file

@ -15,7 +15,7 @@
namespace lean {
template <typename T, typename X>
class lp_primal_simplex: public lp_solver<T, X> {
lp_primal_core_solver<T, X> * m_core_solver = nullptr;
lp_primal_core_solver<T, X> * m_core_solver;
vector<X> m_low_bounds;
private:
unsigned original_rows() { return this->m_external_rows_to_core_solver_rows.size(); }
@ -28,7 +28,7 @@ private:
void set_scaled_costs();
public:
lp_primal_simplex() {}
lp_primal_simplex(): m_core_solver(nullptr) {}
column_info<T> * get_or_create_column_info(unsigned column);

128
src/util/lp/lp_settings.h
View file

@ -106,49 +106,49 @@ private:
default_lp_resource_limit m_default_resource_limit;
lp_resource_limit* m_resource_limit;
// used for debug output
std::ostream* m_debug_out = &std::cout;
std::ostream* m_debug_out;
// used for messages, for example, the computation progress messages
std::ostream* m_message_out = &std::cout;
std::ostream* m_message_out;
stats m_stats;
public:
unsigned reps_in_scaler = 20;
unsigned reps_in_scaler;
// when the absolute value of an element is less than pivot_epsilon
// in pivoting, we treat it as a zero
double pivot_epsilon = 0.00000001;
double pivot_epsilon;
// see Chatal, page 115
double positive_price_epsilon = 1e-7;
double positive_price_epsilon;
// a quatation "if some choice of the entering vairable leads to an eta matrix
// whose diagonal element in the eta column is less than e2 (entering_diag_epsilon) in magnitude, the this choice is rejected ...
double entering_diag_epsilon = 1e-8;
int c_partial_pivoting = 10; // this is the constant c from page 410
unsigned depth_of_rook_search = 4;
bool using_partial_pivoting = true;
double entering_diag_epsilon;
int c_partial_pivoting; // this is the constant c from page 410
unsigned depth_of_rook_search;
bool using_partial_pivoting;
// dissertation of Achim Koberstein
// if Bx - b is different at any component more that refactor_epsilon then we refactor
double refactor_tolerance = 1e-4;
double pivot_tolerance = 1e-6;
double zero_tolerance = 1e-12;
double drop_tolerance = 1e-14;
double tolerance_for_artificials = 1e-4;
double can_be_taken_to_basis_tolerance = 0.00001;
double refactor_tolerance;
double pivot_tolerance;
double zero_tolerance;
double drop_tolerance;
double tolerance_for_artificials;
double can_be_taken_to_basis_tolerance;
unsigned percent_of_entering_to_check = 5; // we try to find a profitable column in a percentage of the columns
bool use_scaling = true;
double scaling_maximum = 1;
double scaling_minimum = 0.5;
double harris_feasibility_tolerance = 1e-7; // page 179 of Istvan Maros
double ignore_epsilon_of_harris = 10e-5;
unsigned max_number_of_iterations_with_no_improvements = 2000000;
unsigned max_total_number_of_iterations = 20000000;
double time_limit = std::numeric_limits<double>::max(); // the maximum time limit of the total run time in seconds
unsigned percent_of_entering_to_check; // we try to find a profitable column in a percentage of the columns
bool use_scaling;
double scaling_maximum;
double scaling_minimum;
double harris_feasibility_tolerance; // page 179 of Istvan Maros
double ignore_epsilon_of_harris;
unsigned max_number_of_iterations_with_no_improvements;
unsigned max_total_number_of_iterations;
double time_limit; // the maximum time limit of the total run time in seconds
// dual section
double dual_feasibility_tolerance = 1e-7; // // page 71 of the PhD thesis of Achim Koberstein
double primal_feasibility_tolerance = 1e-7; // page 71 of the PhD thesis of Achim Koberstein
double relative_primal_feasibility_tolerance = 1e-9; // page 71 of the PhD thesis of Achim Koberstein
double dual_feasibility_tolerance; // // page 71 of the PhD thesis of Achim Koberstein
double primal_feasibility_tolerance; // page 71 of the PhD thesis of Achim Koberstein
double relative_primal_feasibility_tolerance; // page 71 of the PhD thesis of Achim Koberstein
bool m_bound_propagation = true;
bool m_bound_propagation;
bool bound_progation() const {
return m_bound_propagation;
@ -158,7 +158,53 @@ public:
return m_bound_propagation;
}
lp_settings() : m_default_resource_limit(*this), m_resource_limit(&m_default_resource_limit) {}
lp_settings() : m_default_resource_limit(*this),
m_resource_limit(&m_default_resource_limit),
m_debug_out( &std::cout),
m_message_out(&std::cout),
reps_in_scaler(20),
pivot_epsilon(0.00000001),
positive_price_epsilon(1e-7),
entering_diag_epsilon ( 1e-8),
c_partial_pivoting ( 10), // this is the constant c from page 410
depth_of_rook_search ( 4),
using_partial_pivoting ( true),
// dissertation of Achim Koberstein
// if Bx - b is different at any component more that refactor_epsilon then we refactor
refactor_tolerance ( 1e-4),
pivot_tolerance ( 1e-6),
zero_tolerance ( 1e-12),
drop_tolerance ( 1e-14),
tolerance_for_artificials ( 1e-4),
can_be_taken_to_basis_tolerance ( 0.00001),
percent_of_entering_to_check ( 5),// we try to find a profitable column in a percentage of the columns
use_scaling ( true),
scaling_maximum ( 1),
scaling_minimum ( 0.5),
harris_feasibility_tolerance ( 1e-7), // page 179 of Istvan Maros
ignore_epsilon_of_harris ( 10e-5),
max_number_of_iterations_with_no_improvements ( 2000000),
max_total_number_of_iterations ( 20000000),
time_limit ( std::numeric_limits<double>::max()), // the maximum time limit of the total run time in seconds
// dual section
dual_feasibility_tolerance ( 1e-7), // // page 71 of the PhD thesis of Achim Koberstein
primal_feasibility_tolerance ( 1e-7), // page 71 of the PhD thesis of Achim Koberstein
relative_primal_feasibility_tolerance ( 1e-9), // page 71 of the PhD thesis of Achim Koberstein
m_bound_propagation ( true),
presolve_with_double_solver_for_lar(true),
m_simplex_strategy(simplex_strategy_enum::tableau_rows),
report_frequency(1000),
print_statistics(false),
column_norms_update_frequency(12000),
scale_with_ratio(true),
density_threshold(0.7),
use_breakpoints_in_feasibility_search(false),
random_seed(1),
max_row_length_for_bound_propagation(300),
backup_costs(true),
column_number_threshold_for_using_lu_in_lar_solver(4000)
{}
void set_resource_limit(lp_resource_limit& lim) { m_resource_limit = &lim; }
bool get_cancel_flag() const { return m_resource_limit->get_cancel_flag(); }
@ -227,8 +273,8 @@ public:
return is_eps_small_general<T>(t, tolerance_for_artificials);
}
// the method of lar solver to use
bool presolve_with_double_solver_for_lar = true;
simplex_strategy_enum m_simplex_strategy = simplex_strategy_enum::tableau_rows;
bool presolve_with_double_solver_for_lar;
simplex_strategy_enum m_simplex_strategy;
simplex_strategy_enum simplex_strategy() const {
return m_simplex_strategy;
}
@ -250,20 +296,20 @@ public:
return m_simplex_strategy == simplex_strategy_enum::tableau_rows;
}
int report_frequency = 1000;
bool print_statistics = false;
unsigned column_norms_update_frequency = 12000;
bool scale_with_ratio = true;
double density_threshold = 0.7; // need to tune it up, todo
int report_frequency;
bool print_statistics;
unsigned column_norms_update_frequency;
bool scale_with_ratio;
double density_threshold; // need to tune it up, todo
#ifdef LEAN_DEBUG
static unsigned ddd; // used for debugging
#endif
bool use_breakpoints_in_feasibility_search = false;
unsigned random_seed = 1;
bool use_breakpoints_in_feasibility_search;
unsigned random_seed;
static unsigned long random_next;
unsigned max_row_length_for_bound_propagation = 300;
bool backup_costs = true;
unsigned column_number_threshold_for_using_lu_in_lar_solver = 4000;
unsigned max_row_length_for_bound_propagation;
bool backup_costs;
unsigned column_number_threshold_for_using_lu_in_lar_solver;
}; // end of lp_settings class

29
src/util/lp/lp_solver.h
View file

@ -39,10 +39,10 @@ protected:
T get_column_cost_value(unsigned j, column_info<T> * ci) const;
public:
unsigned m_total_iterations;
static_matrix<T, X>* m_A = nullptr; // this is the matrix of constraints
static_matrix<T, X>* m_A; // this is the matrix of constraints
vector<T> m_b; // the right side vector
unsigned m_first_stage_iterations = 0;
unsigned m_second_stage_iterations = 0;
unsigned m_first_stage_iterations;
unsigned m_second_stage_iterations;
std::unordered_map<unsigned, lp_constraint<T, X>> m_constraints;
std::unordered_map<var_index, column_info<T>*> m_map_from_var_index_to_column_info;
std::unordered_map<unsigned, std::unordered_map<unsigned, T> > m_A_values;
@ -52,8 +52,8 @@ public:
std::unordered_map<unsigned, unsigned> m_core_solver_columns_to_external_columns;
vector<T> m_column_scale;
std::unordered_map<unsigned, std::string> m_name_map;
unsigned m_artificials = 0;
unsigned m_slacks = 0;
unsigned m_artificials;
unsigned m_slacks;
vector<column_type> m_column_types;
vector<T> m_costs;
vector<T> m_x;
@ -63,10 +63,17 @@ public:
vector<int> m_heading;
lp_status m_status = lp_status::UNKNOWN;
lp_status m_status;
lp_settings m_settings;
lp_solver() {}
lp_solver():
m_A(nullptr), // this is the matrix of constraints
m_first_stage_iterations (0),
m_second_stage_iterations (0),
m_artificials (0),
m_slacks (0),
m_status(lp_status::UNKNOWN)
{}
unsigned row_count() const { return this->m_A->row_count(); }
@ -232,14 +239,6 @@ protected:
out << "extended A[" << this->m_A->row_count() << "," << this->m_A->column_count() << "]" << std::endl;
}
struct row_tighten_stats {
unsigned n_of_new_bounds = 0;
unsigned n_of_fixed = 0;
bool is_obsolete = false;
};
public:
lp_settings & settings() { return m_settings;}
void print_model(std::ostream & s) const {

6
src/util/lp/lu.h
View file

@ -110,7 +110,7 @@ enum class LU_status { OK, Degenerated};
// Using Suhl-Suhl method described in the dissertation of Achim Koberstein, Chapter 5
template <typename T, typename X>
class lu {
LU_status m_status = LU_status::OK;
LU_status m_status;
public:
// the fields
unsigned m_dim;
@ -123,12 +123,12 @@ public:
vector<tail_matrix<T, X> *> m_tail;
lp_settings & m_settings;
bool m_failure = false;
bool m_failure;
indexed_vector<T> m_row_eta_work_vector;
indexed_vector<T> m_w_for_extension;
indexed_vector<T> m_y_copy;
indexed_vector<unsigned> m_ii; //to optimize the work with the m_index fields
unsigned m_refactor_counter = 0;
unsigned m_refactor_counter;
// constructor
// if A is an m by n matrix then basis has length m and values in [0,n); the values are all different
// they represent the set of m columns

5
src/util/lp/lu.hpp
View file

@ -118,7 +118,10 @@ lu<T, X>::lu(static_matrix<T, X> const & A,
m_r_wave(m_dim),
m_U(A, basis), // create the square matrix that eventually will be factorized
m_settings(settings),
m_row_eta_work_vector(A.row_count()){
m_row_eta_work_vector(A.row_count()),
m_status(LU_status::OK),
m_failure(false),
m_refactor_counter(0) {
lean_assert(!(numeric_traits<T>::precise() && settings.use_tableau()));
#ifdef LEAN_DEBUG
debug_test_of_basis(A, basis);

44
src/util/lp/mps_reader.h
View file

@ -93,22 +93,28 @@ template <typename T, typename X>
class mps_reader {
enum row_type { Cost, Less_or_equal, Greater_or_equal, Equal };
struct bound {
bool m_low_is_set = true;
bool m_low_is_set;
T m_low;
bool m_upper_is_set = false;
bool m_upper_is_set;
T m_upper;
bool m_value_is_fixed = false;
bool m_value_is_fixed;
T m_fixed_value;
bool m_free = false;
bool m_free;
// constructor
bound() : m_low(numeric_traits<T>::zero()) {} // it seems all mps files I have seen have the default low value 0 on a variable
bound() : m_low(numeric_traits<T>::zero()),
m_low_is_set(true),
m_upper_is_set(false),
m_value_is_fixed(false),
m_free(false) {} // it seems all mps files I have seen have the default low value 0 on a variable
};
struct column {
std::string m_name;
bound * m_bound = nullptr;
bound * m_bound;
unsigned m_index;
column(std::string name, unsigned index): m_name(name), m_index(index) {
column(std::string name, unsigned index): m_name(name),
m_bound(nullptr),
m_index(index) {
}
};
@ -116,15 +122,18 @@ class mps_reader {
row_type m_type;
std::string m_name;
std::unordered_map<std::string, T> m_row_columns;
T m_right_side = numeric_traits<T>::zero();
T m_right_side;
unsigned m_index;
T m_range = numeric_traits<T>::zero();
row(row_type type, std::string name, unsigned index) : m_type(type), m_name(name), m_index(index) {
T m_range;
row(row_type type, std::string name, unsigned index) : m_type(type), m_name(name), m_index(index),
m_right_side(zero_of_type<T>()),
m_range(zero_of_type<T>())
{
}
};
std::string m_file_name;
bool m_is_OK = true;
bool m_is_OK;
std::unordered_map<std::string, row *> m_rows;
std::unordered_map<std::string, column *> m_columns;
std::unordered_map<std::string, unsigned> m_names_to_var_index;
@ -133,9 +142,9 @@ class mps_reader {
std::string m_cost_row_name;
std::ifstream m_file_stream;
// needed to adjust the index row
unsigned m_cost_line_count = 0;
unsigned m_line_number = 0;
std::ostream * m_message_stream = & std::cout;
unsigned m_cost_line_count;
unsigned m_line_number;
std::ostream * m_message_stream;
void set_m_ok_to_false() {
*m_message_stream << "setting m_is_OK to false" << std::endl;
@ -737,8 +746,11 @@ public:
}
mps_reader(std::string file_name):
m_file_name(file_name), m_file_stream(file_name) {
}
m_is_OK(true),
m_file_name(file_name), m_file_stream(file_name),
m_cost_line_count(0),
m_line_number(0),
m_message_stream(& std::cout) {}
void read() {
if (!m_file_stream.is_open()){
set_m_ok_to_false();

6
src/util/lp/numeric_pair.h
View file

@ -101,16 +101,14 @@ struct numeric_pair {
numeric_pair(T xp, T yp) : x(xp), y(yp) {}
template <typename X>
numeric_pair(const X & n) : x(n), y(0) {
}
template <typename X>
numeric_pair(const numeric_pair<X> & n) : x(n.x), y(n.y) {}
numeric_pair(const numeric_pair<T> & n) : x(n.x), y(n.y) {}
template <typename X, typename Y>
numeric_pair(X xp, Y yp) : numeric_pair(convert_struct<T, X>::convert(xp), convert_struct<T, Y>::convert(yp)) {}
numeric_pair(X xp, Y yp) : x(convert_struct<T, X>::convert(xp)), y(convert_struct<T, Y>::convert(yp)) {}
bool operator<(const numeric_pair& a) const {
return x < a.x || (x == a.x && y < a.y);

38
src/util/lp/permutation_matrix.h
View file

@ -132,42 +132,4 @@ class permutation_matrix : public tail_matrix<T, X> {
}; // end of the permutation class
#ifdef LEAN_DEBUG
template <typename T, typename X>
class permutation_generator {
unsigned m_n;
permutation_generator* m_lower;
bool m_done = false;
permutation_matrix<T, X> m_current;
unsigned m_last;
public:
permutation_generator(unsigned n);
permutation_generator(const permutation_generator & o);
bool move_next();
~permutation_generator() {
if (m_lower != nullptr) {
delete m_lower;
}
}
permutation_matrix<T, X> *current() {
return &m_current;
}
};
template <typename T, typename X>
inline unsigned number_of_inversions(permutation_matrix<T, X> & p);
template <typename T, typename X>
int sign(permutation_matrix<T, X> & p) {
return is_even(number_of_inversions(p))? 1: -1;
}
template <typename T, typename X>
T det_val_on_perm(permutation_matrix<T, X>* u, const matrix<T, X>& m);
template <typename T, typename X>
T determinant(const matrix<T, X>& m);
#endif
}

96
src/util/lp/permutation_matrix.hpp
View file

@ -320,100 +320,4 @@ template <typename T, typename X> bool permutation_matrix<T, X>::is_identity() c
}
#ifdef LEAN_DEBUG
template <typename T, typename X>
permutation_generator<T, X>::permutation_generator(unsigned n): m_n(n), m_current(n) {
lean_assert(n > 0);
if (n > 1) {
m_lower = new permutation_generator(n - 1);
} else {
m_lower = nullptr;
}
m_last = 0;
}
template <typename T, typename X>
permutation_generator<T, X>::permutation_generator(const permutation_generator & o): m_n(o.m_n), m_done(o.m_done), m_current(o.m_current), m_last(o.m_last) {
if (m_lower != nullptr) {
m_lower = new permutation_generator(o.m_lower);
} else {
m_lower = nullptr;
}
}
template <typename T, typename X> bool
permutation_generator<T, X>::move_next() {
if (m_done) {
return false;
}
if (m_lower == nullptr) {
if (m_last == 0) {
m_last++;
return true;
} else {
m_done = true;
return false;
}
} else {
if (m_last < m_n && m_last > 0) {
m_current[m_last - 1] = m_current[m_last];
m_current[m_last] = m_n - 1;
m_last++;
return true;
} else {
if (m_lower -> move_next()) {
auto lower_curr = m_lower -> current();
for ( unsigned i = 1; i < m_n; i++ ){
m_current[i] = (*lower_curr)[i - 1];
}
m_current[0] = m_n - 1;
m_last = 1;
return true;
} else {
m_done = true;
return false;
}
}
}
}
template <typename T, typename X>
inline unsigned number_of_inversions(permutation_matrix<T, X> & p) {
unsigned ret = 0;
unsigned n = p.size();
for (unsigned i = 0; i < n; i++) {
for (unsigned j = i + 1; j < n; j++) {
if (p[i] > p[j]) {
ret++;
}
}
}
return ret;
}
template <typename T, typename X>
T det_val_on_perm(permutation_matrix<T, X>* u, const matrix<T, X>& m) {
unsigned n = m.row_count();
T ret = numeric_traits<T>::one();
for (unsigned i = 0; i < n; i++) {
unsigned j = (*u)[i];
ret *= m(i, j);
}
return ret * sign(*u);
}
template <typename T, typename X>
T determinant(const matrix<T, X>& m) {
lean_assert(m.column_count() == m.row_count());
unsigned n = m.row_count();
permutation_generator<T, X> allp(n);
T ret = numeric_traits<T>::zero();
while (allp.move_next()){
ret += det_val_on_perm(allp.current(), m);
}
return ret;
}
#endif
}

5
src/util/lp/permutation_matrix_instances.cpp
View file

@ -46,11 +46,6 @@ template void lean::permutation_matrix<lean::mpq, lean::numeric_pair<lean::mpq>
template void lean::permutation_matrix<lean::mpq, lean::numeric_pair<lean::mpq> >::apply_reverse_from_left_to_T(vector<lean::mpq>&);
template void lean::permutation_matrix<lean::mpq, lean::numeric_pair<lean::mpq> >::apply_reverse_from_right_to_T(vector<lean::mpq >&);
template void lean::permutation_matrix<double, double>::multiply_by_permutation_from_right(lean::permutation_matrix<double, double>&);
#ifdef LEAN_DEBUG
template bool lean::permutation_generator<double, double>::move_next();
template lean::permutation_generator<double, double>::permutation_generator(unsigned int);
#endif
template lean::permutation_matrix<double, double>::permutation_matrix(unsigned int);
template void lean::permutation_matrix<double, double>::apply_reverse_from_left_to_X(vector<double> &);
template void lean::permutation_matrix< lean::mpq, lean::mpq>::apply_reverse_from_left_to_X(vector<lean::mpq> &);

9
src/util/lp/random_updater.h
View file

@ -16,12 +16,15 @@ namespace lean {
template <typename T> struct numeric_pair; // forward definition
class lar_core_solver; // forward definition
class random_updater {
unsigned range = 100000;
unsigned range ;
struct interval {
bool upper_bound_is_set = false;
bool upper_bound_is_set;
numeric_pair<mpq> upper_bound;
bool low_bound_is_set = false;
bool low_bound_is_set;
numeric_pair<mpq> low_bound;
interval() : upper_bound_is_set(false),
low_bound_is_set(false) {}
void set_low_bound(const numeric_pair<mpq> & v) {
if (low_bound_is_set) {
low_bound = std::max(v, low_bound);

4
src/util/lp/random_updater.hpp
View file

@ -12,7 +12,9 @@ namespace lean {
random_updater::random_updater(
lar_core_solver & lar_core_solver,
const vector<unsigned> & column_indices) : m_core_solver(lar_core_solver) {
const vector<unsigned> & column_indices) :
m_core_solver(lar_core_solver),
range(100000) {
for (unsigned j : column_indices)
add_column_to_sets(j);
}

6
src/util/lp/sparse_matrix.h
View file

@ -30,10 +30,10 @@ class sparse_matrix
#endif
{
struct col_header {
unsigned m_shortened_markovitz = 0;
unsigned m_shortened_markovitz;
vector<indexed_value<T>> m_values; // the actual column values
col_header() {}
col_header(): m_shortened_markovitz(0) {}
void shorten_markovich_by_one() {
m_shortened_markovitz++;
@ -44,7 +44,7 @@ class sparse_matrix
}
};
unsigned m_n_of_active_elems = 0;
unsigned m_n_of_active_elems;
binary_heap_upair_queue<unsigned> m_pivot_queue;
public:
vector<vector<indexed_value<T>>> m_rows;

3
src/util/lp/sparse_matrix.hpp
View file

@ -40,7 +40,8 @@ sparse_matrix<T, X>::sparse_matrix(static_matrix<T, X> const &A, vector<unsigned
m_row_permutation(A.row_count()),
m_column_permutation(A.row_count()),
m_work_pivot_vector(A.row_count(), -1),
m_processed(A.row_count()) {
m_processed(A.row_count()),
m_n_of_active_elems(0) {
init_row_headers();
init_column_headers();
copy_B(A, basis);

2
src/util/lp/sparse_vector.h
View file

@ -20,7 +20,7 @@ public:
}
#ifdef LEAN_DEBUG
T operator[] (unsigned i) const {
for (auto t : m_data) {
for (auto &t : m_data) {
if (t.first == i) return t.second;
}
return numeric_traits<T>::zero();

2
src/util/lp/square_dense_submatrix.h
View file

@ -42,7 +42,7 @@ public:
unsigned m_index_start;
unsigned m_dim;
vector<T> m_v;
sparse_matrix<T, X> * m_parent = nullptr;
sparse_matrix<T, X> * m_parent;
permutation_matrix<T, X> m_row_permutation;
indexed_vector<T> m_work_vector;
public:

17
src/util/lp/ul_pair.h
View file

@ -32,14 +32,14 @@ inline bool compare(const std::pair<mpq, var_index> & a, const std::pair<mpq, va
}
class ul_pair {
constraint_index m_low_bound_witness = static_cast<constraint_index>(-1);
constraint_index m_upper_bound_witness = static_cast<constraint_index>(-1);
constraint_index m_low_bound_witness;
constraint_index m_upper_bound_witness;
public:
constraint_index& low_bound_witness() {return m_low_bound_witness;}
constraint_index low_bound_witness() const {return m_low_bound_witness;}
constraint_index& upper_bound_witness() { return m_upper_bound_witness;}
constraint_index upper_bound_witness() const {return m_upper_bound_witness;}
row_index m_i = static_cast<row_index>(-1);
row_index m_i;
bool operator!=(const ul_pair & p) const {
return !(*this == p);
}
@ -50,8 +50,15 @@ public:
m_i == p.m_i;
}
// empty constructor
ul_pair(){}
ul_pair(row_index ri) : m_i(ri) {}
ul_pair() :
m_low_bound_witness(static_cast<constraint_index>(-1)),
m_upper_bound_witness(static_cast<constraint_index>(-1)),
m_i(static_cast<row_index>(-1))
{}
ul_pair(row_index ri) :
m_low_bound_witness(static_cast<constraint_index>(-1)),
m_upper_bound_witness(static_cast<constraint_index>(-1)),
m_i(ri) {}
ul_pair(const ul_pair & o): m_low_bound_witness(o.m_low_bound_witness), m_upper_bound_witness(o.m_upper_bound_witness), m_i(o.m_i) {}
};