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Add facilities to get optimal assignments

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This commit is contained in:
Anh-Dung Phan 2013-11-24 22:31:52 +01:00
parent 2ff51e9a60
commit cc3d65e544
6 changed files with 98 additions and 18 deletions
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68
src/smt/theory_arith_aux.h
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@ -966,28 +966,78 @@ namespace smt {
return x_i;
}
template<typename Ext>
bool theory_arith<Ext>::get_theory_vars(expr * n, uint_set & vars) {
rational r;
expr* x, *y;
if (m_util.is_numeral(n, r)) {
return true;
}
else if (m_util.is_add(n)) {
for (unsigned i = 0; i < to_app(n)->get_num_args(); ++i) {
if (!get_theory_vars(to_app(n)->get_arg(i), vars)) {
return false;
}
}
}
else if (m_util.is_mul(n, x, y) && m_util.is_numeral(x, r)) {
return get_theory_vars(y, vars);
}
else if (m_util.is_mul(n, y, x) && m_util.is_numeral(x, r)) {
return get_theory_vars(y, vars);
}
else if (!is_app(n)) {
return false;
}
else if (to_app(n)->get_family_id() == m_util.get_family_id()) {
return false;
}
else {
context & ctx = get_context();
SASSERT(ctx.e_internalized(n));
enode * e = ctx.get_enode(n);
if (is_attached_to_var(e)) {
vars.insert(e->get_th_var(get_id()));
}
return true;
}
return true;
}
//
// add_objective(expr* term) internalizes the arithmetic term and creates
// a row for it if it is not already internalized.
// Then return the variable corresponding to the term.
//
template<typename Ext>
theory_var theory_arith<Ext>::add_objective(app* term) {
return internalize_term_core(term);
theory_var v = internalize_term_core(term);
uint_set vars;
if (get_theory_vars(term, vars)) {
m_objective_vars.insert(v, vars);
}
return v;
}
template<typename Ext>
inf_eps_rational<inf_rational> theory_arith<Ext>::maximize(theory_var v) {
bool r = max_min(v, true);
if (at_upper(v)) {
m_objective_value = get_value(v);
if (r || at_upper(v)) {
if (m_objective_vars.contains(v)) {
// FIXME: put this block inside verbose code
uint_set & vars = m_objective_vars[v];
uint_set::iterator it = vars.begin(), end = vars.end();
ast_manager& m = get_manager();
IF_VERBOSE(1,
verbose_stream() << "Optimal assigment:" << std::endl;
for (; it != end; ++it) {
verbose_stream() << mk_pp(get_enode(*it)->get_owner(), m) << " |-> " << get_value(*it) << std::endl;
};);
}
return inf_eps_rational<inf_rational>(get_value(v));
}
else if (!r) {
m_objective_value = inf_eps_rational<inf_rational>::infinity();
}
return m_objective_value;
return inf_eps_rational<inf_rational>::infinity();
}
/**
@ -1414,8 +1464,6 @@ namespace smt {
TRACE("maximize", tout << "v" << v << " " << (max ? "max" : "min") << " value is: " << get_value(v) << "\n";
display_row(tout, m_tmp_row, true); display_row_info(tout, m_tmp_row););
m_objective_value = get_value(v);
mk_bound_from_row(v, get_value(v), max ? B_UPPER : B_LOWER, m_tmp_row);
return true;