mirror of
https://github.com/Z3Prover/z3
synced 2025-04-06 01:24:08 +00:00
started new PB solver
Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner
parent
0acf331ed1
commit
314f03c12c
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@ -63,11 +63,11 @@ def init_project_def():
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add_lib('tab', ['muz', 'transforms'], 'muz/tab')
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add_lib('bmc', ['muz', 'transforms'], 'muz/bmc')
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add_lib('fp', ['muz', 'pdr', 'clp', 'tab', 'rel', 'bmc'], 'muz/fp')
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add_lib('opt', ['smt'], 'opt')
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add_lib('smtlogic_tactics', ['arith_tactics', 'bv_tactics', 'nlsat_tactic', 'smt_tactic', 'aig_tactic', 'fp', 'muz','qe'], 'tactic/smtlogics')
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add_lib('ufbv_tactic', ['normal_forms', 'core_tactics', 'macros', 'smt_tactic', 'rewriter'], 'tactic/ufbv')
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add_lib('portfolio', ['smtlogic_tactics', 'ufbv_tactic', 'fpa', 'aig_tactic', 'fp', 'qe','sls_tactic', 'subpaving_tactic'], 'tactic/portfolio')
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add_lib('smtparser', ['portfolio'], 'parsers/smt')
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add_lib('opt', ['smt', 'smtlogic_tactics'], 'opt')
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API_files = ['z3_api.h', 'z3_algebraic.h', 'z3_polynomial.h', 'z3_rcf.h']
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add_lib('api', ['portfolio', 'user_plugin', 'smtparser', 'realclosure'],
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includes2install=['z3.h', 'z3_v1.h', 'z3_macros.h'] + API_files)
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@ -18,7 +18,7 @@ Notes:
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--*/
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#include "fu_malik.h"
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#include "smtlogics/qfbv_tactic.h"
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#include "qfbv_tactic.h"
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#include "tactic2solver.h"
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#include "goal.h"
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#include "probe.h"
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703
src/smt/theory_pb.cpp
Normal file
703
src/smt/theory_pb.cpp
Normal file
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@ -0,0 +1,703 @@
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/*++
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Copyright (c) 2013 Microsoft Corporation
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Module Name:
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theory_pb.cpp
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Abstract:
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Pseudo-Boolean theory plugin.
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Author:
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Nikolaj Bjorner (nbjorner) 2013-11-05
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Notes:
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--*/
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#include "theory_pb.h"
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#include "smt_context.h"
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#include "ast_pp.h"
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#include "sorting_network.h"
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namespace smt {
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theory_pb::theory_pb(ast_manager& m):
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theory(m.mk_family_id("card")),
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m_util(m)
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{}
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theory_pb::~theory_pb() {
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reset_eh();
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}
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theory * theory_pb::mk_fresh(context * new_ctx) {
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return alloc(theory_pb, new_ctx->get_manager());
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}
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bool theory_pb::internalize_atom(app * atom, bool gate_ctx) {
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context& ctx = get_context();
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ast_manager& m = get_manager();
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unsigned num_args = atom->get_num_args();
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SASSERT(m_util.is_at_most_k(atom) || m_util.is_le(atom));
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if (ctx.b_internalized(atom)) {
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return false;
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}
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m_stats.m_num_predicates++;
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SASSERT(!ctx.b_internalized(atom));
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bool_var abv = ctx.mk_bool_var(atom);
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ineq* c = alloc(ineq, atom, literal(abv));
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c->m_k = m_util.get_k(atom);
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int& k = c->m_k;
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arg_t& args = c->m_args;
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// extract literals and coefficients.
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for (unsigned i = 0; i < num_args; ++i) {
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expr* arg = atom->get_arg(i);
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literal l = compile_arg(arg);
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int c = m_util.get_le_coeff(atom, i);
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args.push_back(std::make_pair(l, c));
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}
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// turn W <= k into -W >= -k
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for (unsigned i = 0; i < args.size(); ++i) {
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args[i].second = -args[i].second;
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}
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k = -k;
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lbool is_true = normalize_ineq(args, k);
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literal lit(abv);
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switch(is_true) {
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case l_false:
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lit = ~lit;
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// fall-through
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case l_true:
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ctx.mk_th_axiom(get_id(), 1, &lit);
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TRACE("card", tout << mk_pp(atom, m) << " := " << lit << "\n";);
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dealloc(c);
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return true;
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case l_undef:
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break;
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}
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// TBD: special cases: args.size() == 1
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// maximal coefficient:
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int& max_coeff = c->m_max_coeff;
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max_coeff = 0;
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for (unsigned i = 0; i < args.size(); ++i) {
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max_coeff = std::max(max_coeff, args[i].second);
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}
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// compute watch literals:
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int sum = 0;
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unsigned& wsz = c->m_watch_sz;
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wsz = 0;
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while (sum < k + max_coeff && wsz < args.size()) {
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sum += args[wsz].second;
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wsz++;
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}
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for (unsigned i = 0; i < wsz; ++i) {
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add_watch(args[i].first, c);
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}
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// pre-compile threshold for cardinality
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bool is_cardinality = true;
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for (unsigned i = 0; is_cardinality && i < args.size(); ++i) {
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is_cardinality = (args[i].second == 1);
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}
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if (is_cardinality) {
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unsigned log = 1, n = 1;
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while (n <= args.size()) {
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++log;
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n *= 2;
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}
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c->m_compilation_threshold = args.size()*log;
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TRACE("card", tout << "threshold:" << (args.size()*log) << "\n";);
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}
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else {
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c->m_compilation_threshold = UINT_MAX;
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}
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m_ineqs.insert(abv, c);
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m_ineqs_trail.push_back(abv);
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TRACE("card", display(tout, *c););
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return true;
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}
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literal theory_pb::compile_arg(expr* arg) {
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context& ctx = get_context();
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ast_manager& m = get_manager();
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if (!ctx.b_internalized(arg)) {
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ctx.internalize(arg, false);
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}
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bool_var bv;
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bool has_bv = false;
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bool negate = m.is_not(arg, arg);
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if (ctx.b_internalized(arg)) {
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bv = ctx.get_bool_var(arg);
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if (null_theory_var == ctx.get_var_theory(bv)) {
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ctx.set_var_theory(bv, get_id());
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}
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has_bv = (ctx.get_var_theory(bv) == get_id());
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}
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// pre-processing should better remove negations under cardinality.
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// assumes relevancy level = 2 or 0.
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if (!has_bv) {
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expr_ref tmp(m), fml(m);
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tmp = m.mk_fresh_const("card_proxy",m.mk_bool_sort());
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fml = m.mk_iff(tmp, arg);
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ctx.internalize(fml, false);
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SASSERT(ctx.b_internalized(tmp));
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bv = ctx.get_bool_var(tmp);
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SASSERT(null_theory_var == ctx.get_var_theory(bv));
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ctx.set_var_theory(bv, get_id());
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literal lit(ctx.get_bool_var(fml));
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ctx.mk_th_axiom(get_id(), 1, &lit);
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ctx.mark_as_relevant(tmp);
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}
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return negate?~literal(bv):literal(bv);
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}
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void theory_pb::add_watch(literal l, ineq* c) {
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unsigned idx = l.index();
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ptr_vector<ineq>* ineqs;
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if (!m_watch.find(idx, ineqs)) {
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ineqs = alloc(ptr_vector<ineq>);
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m_watch.insert(idx, ineqs);
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}
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ineqs->push_back(c);
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}
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static unsigned gcd(unsigned a, unsigned b) {
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while (a != b) {
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if (a == 0) return b;
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if (b == 0) return a;
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SASSERT(a != 0 && b != 0);
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if (a < b) {
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b %= a;
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}
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else {
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a %= b;
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}
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}
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return a;
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}
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lbool theory_pb::normalize_ineq(arg_t& args, int& k) {
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// normalize first all literals to be positive:
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// then we can can compare them more easily.
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for (unsigned i = 0; i < args.size(); ++i) {
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if (args[i].first.sign()) {
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args[i].first.neg();
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k -= args[i].second;
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args[i].second = -args[i].second;
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}
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}
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// sort and coalesce arguments:
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std::sort(args.begin(), args.end());
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for (unsigned i = 0; i + 1 < args.size(); ++i) {
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if (args[i].first == args[i+1].first) {
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args[i].second += args[i+1].second;
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for (unsigned j = i+1; j + 1 < args.size(); ++j) {
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args[j] = args[j+1];
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}
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args.resize(args.size()-1);
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}
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if (args[i].second == 0) {
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for (unsigned j = i; j + 1 < args.size(); ++j) {
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args[j] = args[j+1];
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}
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args.resize(args.size()-1);
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}
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}
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//
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// Ensure all coefficients are positive:
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// c*l + y >= k
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// <=>
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// c*(1-~l) + y >= k
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// <=>
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// c - c*~l + y >= k
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// <=>
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// -c*~l + y >= k - c
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//
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unsigned sum = 0;
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for (unsigned i = 0; i < args.size(); ++i) {
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int c = args[i].second;
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if (c < 0) {
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args[i].second = -c;
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args[i].first = ~args[i].first;
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k -= c;
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}
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sum += args[i].second;
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}
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// detect tautologies:
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if (k <= 0) {
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args.reset();
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return l_true;
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}
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// detect infeasible constraints:
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if (static_cast<int>(sum) < k) {
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args.reset();
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return l_false;
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}
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// Ensure the largest coefficient is not larger than k:
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for (unsigned i = 0; i < args.size(); ++i) {
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int c = args[i].second;
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if (c > k) {
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args[i].second = k;
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}
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}
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SASSERT(!args.empty());
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// apply cutting plane reduction:
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unsigned g = 0;
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for (unsigned i = 0; g != 1 && i < args.size(); ++i) {
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int c = args[i].second;
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if (c != k) {
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g = gcd(g, c);
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}
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}
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if (g == 0) {
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// all coefficients are equal to k.
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for (unsigned i = 0; i < args.size(); ++i) {
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SASSERT(args[i].second == k);
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args[i].second = 1;
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}
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k = 1;
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}
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else if (g > 1) {
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//
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// Example 5x + 5y + 2z + 2u >= 5
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// becomes 3x + 3y + z + u >= 3
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//
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int k_new = k / g; // k_new is the ceiling of k / g.
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if (gcd(k, g) != g) {
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k_new++;
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}
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for (unsigned i = 0; i < args.size(); ++i) {
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int c = args[i].second;
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if (c == k) {
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c = k_new;
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}
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else {
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c = c / g;
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}
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args[i].second = c;
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}
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k = k_new;
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}
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return l_undef;
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}
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void theory_pb::collect_statistics(::statistics& st) const {
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st.update("pb axioms", m_stats.m_num_axioms);
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st.update("pb propagations", m_stats.m_num_propagations);
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st.update("pb predicates", m_stats.m_num_predicates);
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st.update("pb compilations", m_stats.m_num_compiles);
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}
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void theory_pb::reset_eh() {
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// m_watch;
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u_map<ptr_vector<ineq>*>::iterator it = m_watch.begin(), end = m_watch.end();
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for (; it != end; ++it) {
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dealloc(it->m_value);
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}
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u_map<ineq*>::iterator itc = m_ineqs.begin(), endc = m_ineqs.end();
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for (; itc != endc; ++itc) {
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dealloc(itc->m_value);
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}
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m_watch.reset();
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m_ineqs.reset();
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m_ineqs_trail.reset();
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m_ineqs_lim.reset();
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m_stats.reset();
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}
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#if 0
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void theory_pb::propagate_assignment(ineq& c) {
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if (c.m_compiled) {
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return;
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}
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if (should_compile(c)) {
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compile_ineq(c);
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return;
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}
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context& ctx = get_context();
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ast_manager& m = get_manager();
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arg_t const& args = c.m_args;
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bool_var abv = c.m_bv;
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int min = c.m_current_min;
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int max = c.m_current_max;
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int k = c.m_k;
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TRACE("card",
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tout << mk_pp(c.m_app, m) << " min: "
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<< min << " max: " << max << "\n";);
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//
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// if min > k && abv != l_false -> force abv false
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// if max <= k && abv != l_true -> force abv true
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// if min == k && abv == l_true -> force positive
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// unassigned literals false
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// if max == k + 1 && abv == l_false -> force negative
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// unassigned literals false
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//
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lbool aval = ctx.get_assignment(abv);
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if (min > k && aval != l_false) {
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literal_vector& lits = get_lits();
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int curr_min = accumulate_min(lits, c);
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SASSERT(curr_min > k);
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add_assign(c, lits, ~literal(abv));
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}
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else if (max <= k && aval != l_true) {
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literal_vector& lits = get_lits();
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int curr_max = accumulate_max(lits, c);
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SASSERT(curr_max <= k);
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add_assign(c, lits, literal(abv));
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}
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else if (min <= k && k < min + get_max_delta(c) && aval == l_true) {
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literal_vector& lits = get_lits();
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lits.push_back(~literal(abv));
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int curr_min = accumulate_min(lits, c);
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if (curr_min > k) {
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add_clause(c, lits);
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}
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else {
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for (unsigned i = 0; i < args.size(); ++i) {
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bool_var bv = args[i].first;
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int inc = args[i].second;
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if (curr_min + inc > k && inc_min(inc, ctx.get_assignment(bv)) == l_undef) {
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add_assign(c, lits, literal(bv, inc > 0));
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}
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}
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}
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}
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else if (max - get_max_delta(c) <= k && k < max && aval == l_false) {
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literal_vector& lits = get_lits();
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lits.push_back(literal(abv));
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int curr_max = accumulate_max(lits, c);
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if (curr_max <= k) {
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add_clause(c, lits);
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}
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else {
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for (unsigned i = 0; i < args.size(); ++i) {
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bool_var bv = args[i].first;
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int inc = args[i].second;
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if (curr_max - abs(inc) <= k && dec_max(inc, ctx.get_assignment(bv)) == l_undef) {
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add_assign(c, lits, literal(bv, inc < 0));
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}
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}
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}
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}
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else if (aval == l_true) {
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SASSERT(min < k);
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literal_vector& lits = get_lits();
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int curr_min = accumulate_min(lits, c);
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bool all_inc = curr_min == k;
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unsigned num_incs = 0;
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for (unsigned i = 0; all_inc && i < args.size(); ++i) {
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bool_var bv = args[i].first;
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int inc = args[i].second;
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if (inc_min(inc, ctx.get_assignment(bv)) == l_undef) {
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all_inc = inc + min > k;
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num_incs++;
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}
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}
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if (num_incs > 0) {
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std::cout << "missed T propgations " << num_incs << "\n";
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}
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}
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else if (aval == l_false) {
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literal_vector& lits = get_lits();
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lits.push_back(literal(abv));
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int curr_max = accumulate_max(lits, c);
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bool all_dec = curr_max > k;
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unsigned num_decs = 0;
|
||||
for (unsigned i = 0; all_dec && i < args.size(); ++i) {
|
||||
bool_var bv = args[i].first;
|
||||
int inc = args[i].second;
|
||||
if (dec_max(inc, ctx.get_assignment(bv)) == l_undef) {
|
||||
all_dec = inc + max <= k;
|
||||
num_decs++;
|
||||
}
|
||||
}
|
||||
if (num_decs > 0) {
|
||||
std::cout << "missed F propgations " << num_decs << "\n";
|
||||
}
|
||||
}
|
||||
}
|
||||
#endif
|
||||
|
||||
void theory_pb::assign_eh(bool_var v, bool is_true) {
|
||||
context& ctx = get_context();
|
||||
ast_manager& m = get_manager();
|
||||
ptr_vector<ineq>* ineqs = 0;
|
||||
ineq* c = 0;
|
||||
TRACE("card", tout << "assign: " << mk_pp(ctx.bool_var2expr(v), m) << " <- " << is_true << "\n";);
|
||||
|
||||
if (m_watch.find(v, ineqs)) {
|
||||
for (unsigned i = 0; i < ineqs->size(); ++i) {
|
||||
// TBD: assign_use(v, is_true, *(*ineqs)[i]);
|
||||
}
|
||||
}
|
||||
if (m_ineqs.find(v, c)) {
|
||||
// TBD: propagate_assignment(*c);
|
||||
}
|
||||
}
|
||||
|
||||
struct theory_pb::sort_expr {
|
||||
theory_pb& th;
|
||||
context& ctx;
|
||||
ast_manager& m;
|
||||
expr_ref_vector m_trail;
|
||||
sort_expr(theory_pb& th):
|
||||
th(th),
|
||||
ctx(th.get_context()),
|
||||
m(th.get_manager()),
|
||||
m_trail(m) {}
|
||||
typedef expr* T;
|
||||
typedef expr_ref_vector vector;
|
||||
|
||||
T mk_ite(T a, T b, T c) {
|
||||
if (m.is_true(a)) {
|
||||
return b;
|
||||
}
|
||||
if (m.is_false(a)) {
|
||||
return c;
|
||||
}
|
||||
if (b == c) {
|
||||
return b;
|
||||
}
|
||||
m_trail.push_back(m.mk_ite(a, b, c));
|
||||
return m_trail.back();
|
||||
}
|
||||
|
||||
T mk_le(T a, T b) {
|
||||
return mk_ite(b, a, m.mk_true());
|
||||
}
|
||||
|
||||
T mk_default() {
|
||||
return m.mk_false();
|
||||
}
|
||||
|
||||
literal internalize(ineq& ca, expr* e) {
|
||||
obj_map<expr, literal> cache;
|
||||
for (unsigned i = 0; i < ca.m_args.size(); ++i) {
|
||||
cache.insert(ca.m_app->get_arg(i), literal(ca.m_args[i].first));
|
||||
}
|
||||
cache.insert(m.mk_false(), false_literal);
|
||||
cache.insert(m.mk_true(), true_literal);
|
||||
ptr_vector<expr> todo;
|
||||
todo.push_back(e);
|
||||
expr *a, *b, *c;
|
||||
literal la, lb, lc;
|
||||
while (!todo.empty()) {
|
||||
expr* t = todo.back();
|
||||
if (cache.contains(t)) {
|
||||
todo.pop_back();
|
||||
continue;
|
||||
}
|
||||
VERIFY(m.is_ite(t, a, b, c));
|
||||
unsigned sz = todo.size();
|
||||
if (!cache.find(a, la)) {
|
||||
todo.push_back(a);
|
||||
}
|
||||
if (!cache.find(b, lb)) {
|
||||
todo.push_back(b);
|
||||
}
|
||||
if (!cache.find(c, lc)) {
|
||||
todo.push_back(c);
|
||||
}
|
||||
if (sz != todo.size()) {
|
||||
continue;
|
||||
}
|
||||
todo.pop_back();
|
||||
cache.insert(t, mk_ite(ca, t, la, lb, lc));
|
||||
}
|
||||
return cache.find(e);
|
||||
}
|
||||
|
||||
literal mk_ite(ineq& ca, expr* t, literal a, literal b, literal c) {
|
||||
if (a == true_literal) {
|
||||
return b;
|
||||
}
|
||||
else if (a == false_literal) {
|
||||
return c;
|
||||
}
|
||||
else if (b == true_literal && c == false_literal) {
|
||||
return a;
|
||||
}
|
||||
else if (b == false_literal && c == true_literal) {
|
||||
return ~a;
|
||||
}
|
||||
else if (b == c) {
|
||||
return b;
|
||||
}
|
||||
else {
|
||||
literal l;
|
||||
if (ctx.b_internalized(t)) {
|
||||
l = literal(ctx.get_bool_var(t));
|
||||
}
|
||||
else {
|
||||
l = literal(ctx.mk_bool_var(t));
|
||||
}
|
||||
add_clause(~l, ~a, b);
|
||||
add_clause(~l, a, c);
|
||||
add_clause(l, ~a, ~b);
|
||||
add_clause(l, a, ~c);
|
||||
TRACE("card", tout << mk_pp(t, m) << " ::= (if ";
|
||||
ctx.display_detailed_literal(tout, a);
|
||||
ctx.display_detailed_literal(tout << " ", b);
|
||||
ctx.display_detailed_literal(tout << " ", c);
|
||||
tout << ")\n";);
|
||||
return l;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
// auxiliary clauses don't get garbage collected.
|
||||
void add_clause(literal a, literal b, literal c) {
|
||||
literal_vector& lits = th.get_lits();
|
||||
if (a != null_literal) lits.push_back(a);
|
||||
if (b != null_literal) lits.push_back(b);
|
||||
if (c != null_literal) lits.push_back(c);
|
||||
justification* js = 0;
|
||||
TRACE("card",
|
||||
ctx.display_literals_verbose(tout, lits.size(), lits.c_ptr()); tout << "\n";);
|
||||
ctx.mk_clause(lits.size(), lits.c_ptr(), js, CLS_AUX, 0);
|
||||
}
|
||||
|
||||
void add_clause(literal l1, literal l2) {
|
||||
add_clause(l1, l2, null_literal);
|
||||
}
|
||||
|
||||
};
|
||||
|
||||
|
||||
bool theory_pb::should_compile(ineq& c) {
|
||||
#if 1
|
||||
return false;
|
||||
#else
|
||||
return c.m_num_propagations > c.m_compilation_threshold;
|
||||
#endif
|
||||
}
|
||||
|
||||
void theory_pb::compile_ineq(ineq& c) {
|
||||
++m_stats.m_num_compiles;
|
||||
ast_manager& m = get_manager();
|
||||
context& ctx = get_context();
|
||||
app* a = c.m_app;
|
||||
SASSERT(m_util.is_at_most_k(a));
|
||||
literal atmostk;
|
||||
int k = m_util.get_k(a);
|
||||
unsigned num_args = a->get_num_args();
|
||||
|
||||
sort_expr se(*this);
|
||||
if (k >= static_cast<int>(num_args)) {
|
||||
atmostk = true_literal;
|
||||
}
|
||||
else if (k < 0) {
|
||||
atmostk = false_literal;
|
||||
}
|
||||
else {
|
||||
sorting_network<sort_expr> sn(se);
|
||||
expr_ref_vector in(m), out(m);
|
||||
for (unsigned i = 0; i < num_args; ++i) {
|
||||
in.push_back(c.m_app->get_arg(i));
|
||||
}
|
||||
sn(in, out);
|
||||
atmostk = ~se.internalize(c, out[k].get()); // k'th output is 0.
|
||||
TRACE("card", tout << "~atmost: " << mk_pp(out[k].get(), m) << "\n";);
|
||||
}
|
||||
literal thl = c.m_lit;
|
||||
se.add_clause(~thl, atmostk);
|
||||
se.add_clause(thl, ~atmostk);
|
||||
TRACE("card", tout << mk_pp(a, m) << "\n";);
|
||||
// auxiliary clauses get removed when popping scopes.
|
||||
// we have to recompile the circuit after back-tracking.
|
||||
ctx.push_trail(value_trail<context, bool>(c.m_compiled));
|
||||
c.m_compiled = true;
|
||||
}
|
||||
|
||||
|
||||
void theory_pb::init_search_eh() {
|
||||
|
||||
}
|
||||
|
||||
void theory_pb::push_scope_eh() {
|
||||
m_ineqs_lim.push_back(m_ineqs_trail.size());
|
||||
}
|
||||
|
||||
void theory_pb::pop_scope_eh(unsigned num_scopes) {
|
||||
unsigned sz = m_ineqs_lim[m_ineqs_lim.size()-num_scopes];
|
||||
while (m_ineqs_trail.size() > sz) {
|
||||
SASSERT(m_ineqs.contains(m_ineqs_trail.back()));
|
||||
m_ineqs.remove(m_ineqs_trail.back());
|
||||
m_ineqs_trail.pop_back();
|
||||
}
|
||||
m_ineqs_lim.resize(m_ineqs_lim.size()-num_scopes);
|
||||
}
|
||||
|
||||
std::ostream& theory_pb::display(std::ostream& out, ineq& c) const {
|
||||
ast_manager& m = get_manager();
|
||||
out << mk_pp(c.m_app, m) << "\n";
|
||||
for (unsigned i = 0; i < c.m_args.size(); ++i) {
|
||||
out << c.m_args[i].second << "*" << c.m_args[i].first;
|
||||
if (i + 1 < c.m_args.size()) {
|
||||
out << " + ";
|
||||
}
|
||||
}
|
||||
out << " >= " << c.m_k << "\n"
|
||||
<< "propagations: " << c.m_num_propagations
|
||||
<< " max_coeff: " << c.m_max_coeff
|
||||
<< " watch size: " << c.m_watch_sz
|
||||
<< "\n";
|
||||
return out;
|
||||
}
|
||||
|
||||
|
||||
literal_vector& theory_pb::get_lits() {
|
||||
m_literals.reset();
|
||||
return m_literals;
|
||||
}
|
||||
|
||||
void theory_pb::add_assign(ineq& c, literal_vector const& lits, literal l) {
|
||||
literal_vector ls;
|
||||
++c.m_num_propagations;
|
||||
m_stats.m_num_propagations++;
|
||||
context& ctx = get_context();
|
||||
for (unsigned i = 0; i < lits.size(); ++i) {
|
||||
ls.push_back(~lits[i]);
|
||||
}
|
||||
ctx.assign(l, ctx.mk_justification(theory_propagation_justification(get_id(), ctx.get_region(), ls.size(), ls.c_ptr(), l)));
|
||||
}
|
||||
|
||||
|
||||
|
||||
void theory_pb::add_clause(ineq& c, literal_vector const& lits) {
|
||||
++c.m_num_propagations;
|
||||
m_stats.m_num_axioms++;
|
||||
context& ctx = get_context();
|
||||
TRACE("card", tout << "#prop:" << c.m_num_propagations << " - "; ctx.display_literals_verbose(tout, lits.size(), lits.c_ptr()); tout << "\n";);
|
||||
justification* js = 0;
|
||||
ctx.mk_clause(lits.size(), lits.c_ptr(), js, CLS_AUX_LEMMA, 0);
|
||||
IF_VERBOSE(2, ctx.display_literals_verbose(verbose_stream(),
|
||||
lits.size(), lits.c_ptr());
|
||||
verbose_stream() << "\n";);
|
||||
// ctx.mk_th_axiom(get_id(), lits.size(), lits.c_ptr());
|
||||
}
|
||||
}
|
||||
117
src/smt/theory_pb.h
Normal file
117
src/smt/theory_pb.h
Normal file
|
|
@ -0,0 +1,117 @@
|
|||
/*++
|
||||
Copyright (c) 2013 Microsoft Corporation
|
||||
|
||||
Module Name:
|
||||
|
||||
theory_pb.h
|
||||
|
||||
Abstract:
|
||||
|
||||
Cardinality theory plugin.
|
||||
|
||||
Author:
|
||||
|
||||
Nikolaj Bjorner (nbjorner) 2013-11-05
|
||||
|
||||
Notes:
|
||||
|
||||
This custom theory handles cardinality constraints
|
||||
It performs unit propagation and switches to creating
|
||||
sorting circuits if it keeps having to propagate (create new clauses).
|
||||
--*/
|
||||
|
||||
#include "smt_theory.h"
|
||||
#include "card_decl_plugin.h"
|
||||
#include "smt_clause.h"
|
||||
|
||||
namespace smt {
|
||||
class theory_pb : public theory {
|
||||
|
||||
struct sort_expr;
|
||||
typedef svector<std::pair<literal, int> > arg_t;
|
||||
|
||||
struct stats {
|
||||
unsigned m_num_axioms;
|
||||
unsigned m_num_propagations;
|
||||
unsigned m_num_predicates;
|
||||
unsigned m_num_compiles;
|
||||
void reset() { memset(this, 0, sizeof(*this)); }
|
||||
stats() { reset(); }
|
||||
};
|
||||
|
||||
|
||||
struct ineq {
|
||||
app* m_app;
|
||||
literal m_lit; // literal repesenting predicate
|
||||
arg_t m_args; // encode args[0]*coeffs[0]+...+args[n-1]*coeffs[n-1] >= m_k;
|
||||
int m_k; // invariants: m_k > 0, coeffs[i] > 0
|
||||
|
||||
// Watch the first few positions until the sum satisfies:
|
||||
// sum coeffs[i] >= m_lower + max_coeff
|
||||
|
||||
int m_max_coeff; // maximal coefficient.
|
||||
unsigned m_watch_sz; // number of literals being watched.
|
||||
unsigned m_num_propagations;
|
||||
unsigned m_compilation_threshold;
|
||||
bool m_compiled;
|
||||
|
||||
ineq(app* a, literal l):
|
||||
m_app(a),
|
||||
m_lit(l),
|
||||
m_num_propagations(0),
|
||||
m_compilation_threshold(UINT_MAX),
|
||||
m_compiled(false)
|
||||
{}
|
||||
};
|
||||
|
||||
typedef ptr_vector<ineq> watch_list;
|
||||
|
||||
u_map<watch_list*> m_watch; // per literal.
|
||||
u_map<ineq*> m_ineqs; // per inequality.
|
||||
unsigned_vector m_ineqs_trail;
|
||||
unsigned_vector m_ineqs_lim;
|
||||
literal_vector m_literals; // temporary vector
|
||||
card_util m_util;
|
||||
stats m_stats;
|
||||
|
||||
// internalize_atom:
|
||||
lbool normalize_ineq(arg_t& args, int& k);
|
||||
literal compile_arg(expr* arg);
|
||||
void add_watch(literal l, ineq* c);
|
||||
|
||||
std::ostream& display(std::ostream& out, ineq& c) const;
|
||||
|
||||
void add_clause(ineq& c, literal_vector const& lits);
|
||||
void add_assign(ineq& c, literal_vector const& lits, literal l);
|
||||
literal_vector& get_lits();
|
||||
|
||||
//
|
||||
// Utilities to compile cardinality
|
||||
// constraints into a sorting network.
|
||||
//
|
||||
void compile_ineq(ineq& c);
|
||||
bool should_compile(ineq& c);
|
||||
unsigned get_compilation_threshold(ineq& c);
|
||||
public:
|
||||
theory_pb(ast_manager& m);
|
||||
|
||||
virtual ~theory_pb();
|
||||
|
||||
virtual theory * mk_fresh(context * new_ctx);
|
||||
virtual bool internalize_atom(app * atom, bool gate_ctx);
|
||||
virtual bool internalize_term(app * term) { UNREACHABLE(); return false; }
|
||||
virtual void new_eq_eh(theory_var v1, theory_var v2) { }
|
||||
virtual void new_diseq_eh(theory_var v1, theory_var v2) { }
|
||||
virtual bool use_diseqs() const { return false; }
|
||||
virtual bool build_models() const { return false; }
|
||||
virtual final_check_status final_check_eh() { return FC_DONE; }
|
||||
|
||||
virtual void reset_eh();
|
||||
virtual void assign_eh(bool_var v, bool is_true);
|
||||
virtual void init_search_eh();
|
||||
virtual void push_scope_eh();
|
||||
virtual void pop_scope_eh(unsigned num_scopes);
|
||||
virtual void collect_statistics(::statistics & st) const;
|
||||
|
||||
};
|
||||
};
|
||||
Loading…
Reference in a new issue