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debugging diff logic simple simplex

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2014-03-04 21:19:29 -08:00
parent c4b1f5c30e
commit fe61492d5d
3 changed files with 109 additions and 74 deletions
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7
src/smt/theory_diff_logic.h
View file

@ -158,12 +158,13 @@ namespace smt {
unsigned m_asserted_atoms_lim;
unsigned m_asserted_qhead_old;
};
typedef dl_graph<GExt> Graph;
smt_params & m_params;
arith_util m_util;
arith_eq_adapter m_arith_eq_adapter;
theory_diff_logic_statistics m_stats;
dl_graph<GExt> m_graph;
Graph m_graph;
theory_var m_zero; // cache the variable representing the zero variable.
int_vector m_scc_id; // Cheap equality propagation
eq_prop_info_set m_eq_prop_info_set; // set of existing equality prop infos
@ -356,9 +357,7 @@ namespace smt {
void get_implied_bound_antecedents(edge_id bridge_edge, edge_id subsumed_edge, conflict_resolution & cr);
theory_var get_zero(sort* s) const { return m_zero; }
theory_var get_zero(expr* e) const { return m_zero; }
theory_var get_zero() const { return m_zero; }
void inc_conflicts();

135
src/smt/theory_diff_logic_def.h
View file

@ -208,7 +208,7 @@ bool theory_diff_logic<Ext>::internalize_atom(app * n, bool gate_ctx) {
}
else {
target = mk_var(lhs);
source = get_zero(lhs);
source = get_zero();
}
if (is_ge) {
std::swap(target, source);
@ -698,7 +698,7 @@ theory_var theory_diff_logic<Ext>::mk_num(app* n, rational const& r) {
enode* e = 0;
context& ctx = get_context();
if (r.is_zero()) {
v = get_zero(n);
v = get_zero();
}
else if (ctx.e_internalized(n)) {
e = ctx.get_enode(n);
@ -706,7 +706,7 @@ theory_var theory_diff_logic<Ext>::mk_num(app* n, rational const& r) {
SASSERT(v != null_theory_var);
}
else {
theory_var zero = get_zero(n);
theory_var zero = get_zero();
e = ctx.mk_enode(n, false, false, true);
v = mk_var(e);
// internalizer is marking enodes as interpreted whenever the associated ast is a value and a constant.
@ -1006,71 +1006,82 @@ inf_eps_rational<inf_rational> theory_diff_logic<Ext>::maximize(theory_var v) {
IF_VERBOSE(1,
for (unsigned i = 0; i < objective.size(); ++i) {
verbose_stream() << "Coefficient " << objective[i].second << " of theory_var " << objective[i].first << "\n";
verbose_stream() << "Coefficient " << objective[i].second
<< " of theory_var " << objective[i].first << "\n";
}
verbose_stream() << "Free coefficient " << m_objective_consts[v] << "\n";);
#if 0
// disabled until fixed.
// Objective coefficients now become balances
vector<fin_numeral> balances(m_graph.get_num_nodes());
balances.fill(fin_numeral::zero());
fin_numeral sum = fin_numeral::zero();
for (unsigned i = 0; i < objective.size(); ++i) {
fin_numeral balance(objective[i].second);
balances[objective[i].first] = balance;
sum += balance;
}
// HACK: assume that v0 is always value 0
balances[0] = -sum;
TRACE("arith", display(tout););
network_flow<GExt> net_flow(m_graph, balances);
min_flow_result result = net_flow.min_cost();
SASSERT(result != UNBOUNDED);
if (result == OPTIMAL) {
numeral objective_value = net_flow.get_optimal_solution(m_objective_assignments[v], true) + numeral(m_objective_consts[v]);
IF_VERBOSE(1, verbose_stream() << "Optimal value of objective " << v << ": " << objective_value << std::endl;);
DEBUG_CODE(
numeral initial_value = numeral(m_objective_consts[v]);
for (unsigned i = 0; i < objective.size(); ++i) {
initial_value += fin_numeral(objective[i].second) * m_graph.get_assignment(objective[i].first);
}
IF_VERBOSE(1, verbose_stream() << "Initial value of objective " << v << ": " << initial_value << std::endl;);
// FIXME: Network Simplex lose precisions when handling infinitesimals
SASSERT(objective_value >= initial_value.get_rational()););
vector<numeral> & current_assigments = m_objective_assignments[v];
SASSERT(!current_assigments.empty());
// Normalize optimal assignments so that v0 is fixed to 0
for (unsigned i = 1; i < current_assigments.size(); ++i) {
current_assigments[i] -= current_assigments[0];
}
ast_manager& m = get_manager();
IF_VERBOSE(1,
verbose_stream() << "Optimal assigment:" << std::endl;
for (unsigned i = 0; i < objective.size(); ++i) {
theory_var v = objective[i].first;
verbose_stream() << mk_pp(get_enode(v)->get_owner(), m) << " |-> " << current_assigments[v] << std::endl;
});
rational r = objective_value.get_rational().to_rational();
rational i = objective_value.get_infinitesimal().to_rational();
return inf_eps_rational<inf_rational>(inf_rational(r, i));
}
else {
// Dual problem is infeasible, primal problem is unbounded
SASSERT(result == INFEASIBLE);
IF_VERBOSE(1, verbose_stream() << "Unbounded objective" << std::endl;);
return inf_eps_rational<inf_rational>::infinity();
unsigned num_nodes = m_graph.get_num_nodes();
unsigned num_edges = m_graph.get_num_edges();
vector<dl_edge<GExt> > const& es = m_graph.get_all_edges();
S.ensure_var(num_nodes + num_edges + m_objectives.size());
for (unsigned i = 0; i < num_nodes; ++i) {
numeral const& a = m_graph.get_assignment(i);
rational fin = a.get_rational().to_rational();
rational inf = a.get_infinitesimal().to_rational();
mpq_inf q(fin.to_mpq(), inf.to_mpq());
S.set_value(i, q);
}
S.set_lower(get_zero(), mpq_inf(mpq(0), mpq(0)));
S.set_upper(get_zero(), mpq_inf(mpq(0), mpq(0)));
svector<unsigned> vars;
unsynch_mpq_manager mgr;
scoped_mpq_vector coeffs(mgr);
coeffs.push_back(mpq(1));
coeffs.push_back(mpq(-1));
coeffs.push_back(mpq(-1));
vars.resize(3);
for (unsigned i = 0; i < es.size(); ++i) {
dl_edge<GExt> const& e = es[i];
if (e.is_enabled()) {
unsigned base_var = num_nodes + i;
vars[0] = e.get_target();
vars[1] = e.get_source();
vars[2] = base_var;
S.add_row(base_var, 3, vars.c_ptr(), coeffs.c_ptr());
// t - s <= w
// t - s - b = 0, b >= w
numeral const& w = e.get_weight();
rational fin = w.get_rational().to_rational();
rational inf = w.get_infinitesimal().to_rational();
mpq_inf q(fin.to_mpq(),inf.to_mpq());
S.set_upper(base_var, q);
}
}
unsigned w = num_nodes + num_edges + v;
#endif
return inf_eps_rational<inf_rational>::infinity();
// add objective function as row.
coeffs.reset();
vars.reset();
for (unsigned i = 0; i < objective.size(); ++i) {
coeffs.push_back(objective[i].second.to_mpq());
vars.push_back(objective[i].first);
}
coeffs.push_back(mpq(1));
vars.push_back(w);
S.add_row(w, vars.size(), vars.c_ptr(), coeffs.c_ptr());
TRACE("opt", S.display(tout); display(tout););
// optimize
lbool is_sat = S.make_feasible();
if (is_sat == l_undef) {
return inf_eps_rational<inf_rational>::infinity();
}
TRACE("opt", S.display(tout); );
SASSERT(is_sat != l_false);
lbool is_fin = S.minimize(w);
switch (is_fin) {
case l_true: {
simplex::mpq_ext::eps_numeral const& val = S.get_value(w);
inf_rational r(-rational(val.first), -rational(val.second));
TRACE("opt", tout << r << " " << "\n"; );
return inf_eps_rational<inf_rational>(rational(0), r);
}
default:
TRACE("opt", tout << "unbounded\n"; );
return inf_eps_rational<inf_rational>::infinity();
}
}
template<typename Ext>