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fix 0-1 translation bug reported by Klaus Becker

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2015-08-10 16:21:02 +02:00
parent e532657d77
commit 40eb7c9c84
1 changed files with 89 additions and 37 deletions
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126
src/tactic/arith/lia2card_tactic.cpp
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@ -15,6 +15,24 @@ Author:
Notes:
--*/
/*++
Copyright (c) 2013 Microsoft Corporation
Module Name:
lia2card_tactic.cpp
Abstract:
Convert 0-1 integer variables cardinality constraints to built-in cardinality operator.
Author:
Nikolaj Bjorner (nbjorner) 2013-11-5
Notes:
--*/
#include"tactical.h"
#include"cooperate.h"
@ -24,6 +42,7 @@ Notes:
#include"arith_decl_plugin.h"
#include"rewriter_def.h"
#include"ast_util.h"
#include"ast_pp_util.h"
class lia2card_tactic : public tactic {
struct lia_rewriter_cfg : public default_rewriter_cfg {
@ -34,9 +53,17 @@ class lia2card_tactic : public tactic {
vector<rational> coeffs;
rational coeff;
bool is_pb(expr* x, expr* y, expr_ref_vector& args, vector<rational>& coeffs, rational& coeff) {
args.reset();
coeffs.reset();
coeff.reset();
return
t.get_pb_sum(x, rational::one(), args, coeffs, coeff) &&
t.get_pb_sum(y, -rational::one(), args, coeffs, coeff);
}
bool is_le(expr* x, expr* y, expr_ref& result) {
if (t.get_pb_sum(x, rational::one(), args, coeffs, coeff) &&
t.get_pb_sum(y, -rational::one(), args, coeffs, coeff)) {
if (is_pb(x, y, args, coeffs, coeff)) {
result = t.mk_le(coeffs.size(), coeffs.c_ptr(), args.c_ptr(), -coeff);
return true;
}
@ -46,30 +73,40 @@ class lia2card_tactic : public tactic {
}
br_status mk_app_core(func_decl* f, unsigned sz, expr*const* es, expr_ref& result) {
args.reset();
coeffs.reset();
coeff.reset();
if (is_decl_of(f, a.get_family_id(), OP_LE) && is_le(es[0], es[1], result)) {
return BR_DONE;
}
if (is_decl_of(f, a.get_family_id(), OP_GE) && is_le(es[1], es[0], result)) {
return BR_DONE;
else if (is_decl_of(f, a.get_family_id(), OP_GE) && is_le(es[1], es[0], result)) {
}
if (is_decl_of(f, a.get_family_id(), OP_LT) && is_le(es[1], es[0], result)) {
else if (is_decl_of(f, a.get_family_id(), OP_LT) && is_le(es[1], es[0], result)) {
result = m.mk_not(result);
return BR_DONE;
}
if (is_decl_of(f, a.get_family_id(), OP_GT) && is_le(es[0], es[1], result)) {
else if (is_decl_of(f, a.get_family_id(), OP_GT) && is_le(es[0], es[1], result)) {
result = m.mk_not(result);
return BR_DONE;
}
if (m.is_eq(f) &&
t.get_pb_sum(es[0], rational::one(), args, coeffs, coeff) &&
t.get_pb_sum(es[1], -rational::one(), args, coeffs, coeff)) {
else if (m.is_eq(f) && is_pb(es[0], es[1], args, coeffs, coeff)) {
result = t.mk_eq(coeffs.size(), coeffs.c_ptr(), args.c_ptr(), -coeff);
return BR_DONE;
}
return BR_FAILED;
}
else {
return BR_FAILED;
}
TRACE("pbsum", tout << expr_ref(m.mk_app(f, sz, es), m) << " ==>\n" << result << "\n";);
#if 0
expr_ref vc(m);
vc = m.mk_not(m.mk_eq(m.mk_app(f, sz, es), result));
ast_pp_util pp(m);
pp.collect(vc);
std::cout
<< "(push)\n"
<< "(echo \"" << result << "\")\n"
;
pp.display_decls(std::cout);
std::cout
<< "(assert " << vc << ")\n"
<< "(check-sat)\n"
<< "(pop)\n";
#endif
return BR_DONE;
}
bool rewrite_patterns() const { return false; }
@ -192,10 +229,18 @@ public:
if (sz == 1 && weights[0].is_one() && w.is_zero()) {
return m.mk_not(args[0]);
}
if (w.is_neg()) {
DEBUG_CODE(for (unsigned i = 0; i < sz; ++i) SASSERT(weights[i].is_nonneg()); );
return m.mk_false();
}
return m_pb.mk_le(sz, weights, args, w);
}
expr* mk_eq(unsigned sz, rational const* weights, expr* const* args, rational const& w) {
if (w.is_neg()) {
DEBUG_CODE(for (unsigned i = 0; i < sz; ++i) SASSERT(weights[i].is_nonneg()); );
return m.mk_false();
}
if (m_compile_equality) {
return m_pb.mk_eq(sz, weights, args, w);
}
@ -214,6 +259,10 @@ public:
if (sz == 1 && weights[0].is_one() && w.is_zero()) {
return m.mk_not(args[0]);
}
if (w.is_neg()) {
DEBUG_CODE(for (unsigned i = 0; i < sz; ++i) SASSERT(weights[i].is_nonneg()); );
return m.mk_true();
}
return m_pb.mk_ge(sz, weights, args, w);
}
@ -248,12 +297,6 @@ public:
else if (a.is_to_real(x, y)) {
ok = get_sum(y, mul, conds, args, coeffs, coeff);
}
else if (m.is_ite(x, y, z, u) && is_numeral(z, r) && is_numeral(u, q)) {
insert_arg(r*mul, add_conds(conds, y), args, coeffs, coeff);
// q*(1-y) = -q*y + q
coeff += q*mul;
insert_arg(-q*mul, add_conds(conds, y), args, coeffs, coeff);
}
else if (m.is_ite(x, y, z, u)) {
conds.push_back(y);
ok = get_sum(z, mul, conds, args, coeffs, coeff);
@ -261,12 +304,12 @@ public:
conds.push_back(m.mk_not(y));
ok &= get_sum(u, mul, conds, args, coeffs, coeff);
conds.pop_back();
}
}
else if (is_01var(x)) {
insert_arg(mul, add_conds(conds, mk_01(x)), args, coeffs, coeff);
insert_arg(mul, conds, mk_01(x), args, coeffs, coeff);
}
else if (is_numeral(x, r)) {
insert_arg(mul*r, add_conds(conds, m.mk_true()), args, coeffs, coeff);
insert_arg(mul*r, conds, m.mk_true(), args, coeffs, coeff);
}
else {
TRACE("pb", tout << "Can't handle " << mk_pp(x, m) << "\n";);
@ -275,10 +318,15 @@ public:
return ok;
}
expr_ref add_conds(expr_ref_vector const& es, expr* e) {
if (es.empty()) return expr_ref(e, m);
expr_ref result = expr_ref(m.mk_and(es.size(), es.c_ptr()), m);
result = m.mk_and(e, result);
expr_ref add_conds(expr_ref_vector& es, expr* e) {
expr_ref result(m);
if (!m.is_true(e)) {
es.push_back(e);
}
result = mk_and(m, es.size(), es.c_ptr());
if (!m.is_true(e)) {
es.pop_back();
}
return result;
}
@ -293,19 +341,23 @@ public:
return a.is_numeral(e, r);
}
void insert_arg(rational const& p, expr* x,
expr_ref_vector& args, vector<rational>& coeffs, rational& coeff) {
if (m.is_true(x)) {
void insert_arg(
rational const& p,
expr_ref_vector& conds,
expr* x,
expr_ref_vector& args, vector<rational>& coeffs, rational& coeff) {
expr_ref cond = add_conds(conds, x);
if (m.is_true(cond)) {
coeff += p;
}
else if (p.is_neg()) {
// p*x = -p*(1-x) + p
args.push_back(m.mk_not(x));
// -p*x = p*(1-x) - p
args.push_back(m.mk_not(cond));
coeffs.push_back(-p);
coeff += p;
}
else if (p.is_pos()) {
args.push_back(x);
args.push_back(cond);
coeffs.push_back(p);
}
}