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adding simplex

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2014-02-11 17:15:09 -08:00
parent 596796f7ef
commit 8b5390c56f
3 changed files with 80 additions and 11 deletions
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4
src/math/simplex/simplex_def.h
View file

@ -41,10 +41,10 @@ namespace simplex {
}
}
}
em.neg(value);
em.div(value, base_coeff, value);
SASSERT(!m.is_zero(base_coeff));
SASSERT(!is_base(base));
em.neg(value);
em.div(value, base_coeff, value);
while (m_row2base.size() <= r.id()) {
m_row2base.push_back(null_var);
}

76
src/smt/theory_pb.cpp
View file

@ -190,6 +190,37 @@ namespace smt {
return alloc(theory_pb, new_ctx->get_manager(), m_params);
}
class theory_pb::remove_var : public trail<context> {
theory_pb& pb;
unsigned v;
public:
remove_var(theory_pb& pb, unsigned v): pb(pb), v(v) {}
virtual void undo(context& ctx) {
pb.m_vars.remove(v);
pb.m_simplex.unset_lower(v);
pb.m_simplex.unset_upper(v);
}
};
class reset_bound : public trail<context> {
theory_pb& pb;
unsigned v;
bool is_lower;
public:
reset_bound(theory_pb& pb, unsigned v, bool is_lower):pb(pb), v(v), is_lower(is_lower) {}
virtual void undo(context& ctx) {
}
};
class undo_bound : public trail<context> {
theory_pb& pb;
unsigned v;
bool is_lower;
public:
undo_bound(theory_pb& pb, unsigned v, bool is_lower):pb(pb), v(v), is_lower(is_lower) {}
virtual void undo(context& ctx) {
}
};
bool theory_pb::internalize_atom(app * atom, bool gate_ctx) {
SASSERT(m_util.is_at_most_k(atom) || m_util.is_le(atom) ||
@ -243,7 +274,7 @@ namespace smt {
literal lit(abv);
TRACE("pb", display(tout << mk_pp(atom, m), *c); tout << " := " << lit << "\n";);
TRACE("pb", display(tout, *c); tout << " := " << lit << "\n";);
switch(is_true) {
case l_false:
lit = ~lit;
@ -317,7 +348,10 @@ namespace smt {
if (m_ineq_rep.find(rep, abv2)) {
slack = abv2;
r = m_ineq_row_info.find(abv2).m_row;
TRACE("pb", tout << "Found: " << abv << " |-> " << slack << " " << m_ineq_row_info.find(abv2).m_bound << " vs. " << k << "\n";);
TRACE("pb",
tout << "Old row: " << abv << " |-> " << slack << " ";
tout << m_ineq_row_info.find(abv2).m_bound << " vs. " << k << "\n";
display(tout, rep););
}
else {
m_ineq_rep.insert(rep, abv);
@ -326,15 +360,23 @@ namespace smt {
scoped_mpz_vector coeffs(mgr);
for (unsigned i = 0; i < rep.size(); ++i) {
unsigned v = rep.lit(i).var();
std::cout << v << "\n";
m_simplex.ensure_var(v);
vars.push_back(v);
if (!m_vars.contains(v)) {
mpq_inf zero(mpq(0),mpq(0)), one(mpq(1),mpq(0));
m_simplex.set_lower(v, zero);
m_simplex.set_upper(v, one);
m_vars.insert(v);
ctx.push_trail(remove_var(*this, v));
}
coeffs.push_back(rep.coeff(i).to_mpq().numerator());
}
slack = abv;
m_simplex.ensure_var(abv);
r = m_simplex.add_row(vars.size(), slack, vars.c_ptr(), coeffs.c_ptr());
TRACE("pb", tout << "New row: " << abv << " " << k << "\n";);
m_simplex.ensure_var(slack);
vars.push_back(slack);
coeffs.push_back(mpz(-1));
r = m_simplex.add_row(slack, vars.size(), vars.c_ptr(), coeffs.c_ptr());
TRACE("pb", tout << "New row: " << abv << " " << k << "\n"; display(tout, rep););
}
m_ineq_row_info.insert(abv, row_info(slack, k, rep, r));
}
@ -550,6 +592,18 @@ namespace smt {
else {
assign_eq(*c, is_true);
}
if (m_enable_simplex) {
row_info const& info = m_ineq_row_info.find(v);
if (is_true) {
// m_simplex.set_lower(info.m_slack, info.m_coeff);
// ctx.push_trail(reset_lower(info.m_slack));
}
else {
// m_simplex.set_upper(info.m_slack, info.m_coeff - 1);
// ctx.push_trail(reset_upper(info.m_slack));
}
// m_simplex.feasiable();
}
}
}
@ -1184,6 +1238,16 @@ namespace smt {
clear_watch(*c);
m_ineqs.remove(v);
m_ineqs_trail.pop_back();
if (m_enable_simplex) {
row_info r_info;
VERIFY(m_ineq_row_info.find(v, r_info));
m_simplex.del_row(r_info.m_row);
m_ineq_row_info.erase(v);
bool_var v2 = m_ineq_rep.find(r_info.m_rep);
if (v == v2) {
m_ineq_rep.erase(r_info.m_rep);
}
}
dealloc(c);
}
m_ineqs_lim.resize(new_lim);

11
src/smt/theory_pb.h
View file

@ -36,6 +36,9 @@ namespace smt {
class unwatch_ge;
class rewatch_vars;
class negate_ineq;
class remove_var;
class reset_bound;
class undo_bound;
typedef rational numeral;
typedef vector<std::pair<literal, numeral> > arg_t;
typedef simplex::simplex<simplex::mpz_ext> simplex;
@ -159,14 +162,16 @@ namespace smt {
};
typedef ptr_vector<ineq> watch_list;
typedef map<ineq, bool_var, ineq::hash, ineq::eq> ineq_map;
theory_pb_params m_params;
u_map<watch_list*> m_lwatch; // per literal.
u_map<watch_list*> m_vwatch; // per variable.
u_map<ineq*> m_ineqs; // per inequality.
map<ineq, bool_var, ineq::hash, ineq::eq> m_ineq_rep; // Simplex: representative inequality
u_map<row_info> m_ineq_row_info; // Simplex: row information per variable.
simplex m_simplex; // Simplex
ineq_map m_ineq_rep; // Simplex: representative inequality
u_map<row_info> m_ineq_row_info; // Simplex: row information per variable
uint_set m_vars; // Simplex: 0-1 variables.
simplex m_simplex; // Simplex: tableau
unsigned_vector m_ineqs_trail;
unsigned_vector m_ineqs_lim;
literal_vector m_literals; // temporary vector