z3-z3-4.13.0.src.tactic.goal.cpp Maven / Gradle / Ivy
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/*++
Copyright (c) 2011 Microsoft Corporation
Module Name:
goal.cpp
Abstract:
Proof / Model finding Goals
Author:
Leonardo de Moura (leonardo) 2011-10-12
Revision History:
--*/
#include "ast/ast_ll_pp.h"
#include "ast/ast_smt2_pp.h"
#include "ast/ast_pp.h"
#include "ast/for_each_expr.h"
#include "ast/well_sorted.h"
#include "ast/display_dimacs.h"
#include "tactic/goal.h"
goal::precision goal::mk_union(precision p1, precision p2) {
if (p1 == PRECISE) return p2;
if (p2 == PRECISE) return p1;
if (p1 != p2) return UNDER_OVER;
return p1;
}
std::ostream & operator<<(std::ostream & out, goal::precision p) {
switch (p) {
case goal::PRECISE: out << "precise"; break;
case goal::UNDER: out << "under"; break;
case goal::OVER: out << "over"; break;
case goal::UNDER_OVER: out << "under-over"; break;
}
return out;
}
goal::goal(ast_manager & m, bool models_enabled, bool core_enabled):
m_manager(m),
m_ref_count(0),
m_depth(0),
m_models_enabled(models_enabled),
m_proofs_enabled(m.proofs_enabled()),
m_core_enabled(core_enabled),
m_inconsistent(false),
m_precision(PRECISE) {
}
goal::goal(ast_manager & m, bool proofs_enabled, bool models_enabled, bool core_enabled):
m_manager(m),
m_ref_count(0),
m_depth(0),
m_models_enabled(models_enabled),
m_proofs_enabled(proofs_enabled),
m_core_enabled(core_enabled),
m_inconsistent(false),
m_precision(PRECISE) {
SASSERT(!proofs_enabled || m.proofs_enabled());
}
goal::goal(goal const & src):
m_manager(src.m()),
m_ref_count(0),
m_depth(0),
m_models_enabled(src.models_enabled()),
m_proofs_enabled(src.proofs_enabled()),
m_core_enabled(src.unsat_core_enabled()),
m_inconsistent(false),
m_precision(PRECISE) {
copy_from(src);
}
// Copy configuration: depth, models/proofs/cores flags, and precision from src.
// The assertions are not copied
goal::goal(goal const & src, bool):
m_manager(src.m()),
m_ref_count(0),
m_depth(src.m_depth),
m_models_enabled(src.models_enabled()),
m_proofs_enabled(src.proofs_enabled()),
m_core_enabled(src.unsat_core_enabled()),
m_inconsistent(false),
m_precision(src.m_precision) {
m_mc = src.m_mc.get();
m_pc = src.m_pc.get();
m_dc = src.m_dc.get();
}
goal::~goal() {
reset_core();
}
void goal::copy_to(goal & target) const {
SASSERT(&m_manager == &(target.m_manager));
if (this == &target)
return;
m().copy(m_forms, target.m_forms);
m().copy(m_proofs, target.m_proofs);
m().copy(m_dependencies, target.m_dependencies);
target.m_depth = std::max(m_depth, target.m_depth);
SASSERT(target.m_proofs_enabled == m_proofs_enabled);
SASSERT(target.m_core_enabled == m_core_enabled);
target.m_inconsistent = m_inconsistent;
target.m_precision = mk_union(prec(), target.prec());
target.m_mc = m_mc.get();
target.m_pc = m_pc.get();
target.m_dc = m_dc.get();
}
void goal::push_back(expr * f, proof * pr, expr_dependency * d) {
SASSERT(!proofs_enabled() || pr);
if (m().is_true(f))
return;
if (m().is_false(f)) {
// Make sure pr and d are not deleted by the m().del(...) statements.
proof_ref saved_pr(m());
expr_dependency_ref saved_d(m());
saved_pr = pr;
saved_d = d;
m().del(m_forms);
m().del(m_proofs);
m().del(m_dependencies);
m_inconsistent = true;
m().push_back(m_forms, m().mk_false());
m().push_back(m_proofs, saved_pr);
if (unsat_core_enabled())
m().push_back(m_dependencies, saved_d);
}
else {
SASSERT(!pr || m().get_fact(pr) == f);
SASSERT(!m_inconsistent);
m().push_back(m_forms, f);
m().push_back(m_proofs, pr);
if (unsat_core_enabled())
m().push_back(m_dependencies, d);
}
}
void goal::quick_process(bool save_first, expr_ref& f, expr_dependency * d) {
expr* g = nullptr;
if (!m().is_and(f) && !(m().is_not(f, g) && m().is_or(g))) {
if (!save_first) {
push_back(f, nullptr, d);
}
return;
}
typedef std::pair expr_pol;
sbuffer todo;
expr_ref_vector tmp_exprs(m());
todo.push_back(expr_pol(f, true));
while (!todo.empty()) {
if (m_inconsistent)
return;
auto [curr, pol] = todo.back();
todo.pop_back();
if (pol && m().is_and(curr)) {
app * t = to_app(curr);
unsigned i = t->get_num_args();
while (i > 0) {
--i;
todo.push_back(expr_pol(t->get_arg(i), true));
}
}
else if (!pol && m().is_or(curr)) {
app * t = to_app(curr);
unsigned i = t->get_num_args();
while (i > 0) {
--i;
todo.push_back(expr_pol(t->get_arg(i), false));
}
}
else if (m().is_not(curr, g)) {
todo.push_back(expr_pol(g, !pol));
}
else {
if (!pol) {
curr = m().mk_not(curr);
tmp_exprs.push_back(curr);
}
if (save_first) {
f = curr;
save_first = false;
}
else {
push_back(curr, nullptr, d);
}
}
}
}
void goal::process_and(bool save_first, app * f, proof * pr, expr_dependency * d, expr_ref & out_f, proof_ref & out_pr) {
unsigned num = f->get_num_args();
for (unsigned i = 0; i < num; i++) {
if (m_inconsistent)
return;
slow_process(save_first && i == 0, f->get_arg(i), m().mk_and_elim(pr, i), d, out_f, out_pr);
}
}
void goal::process_not_or(bool save_first, app * f, proof * pr, expr_dependency * d, expr_ref & out_f, proof_ref & out_pr) {
unsigned num = f->get_num_args();
for (unsigned i = 0; i < num; i++) {
if (m_inconsistent)
return;
expr * child = f->get_arg(i);
if (m().is_not(child)) {
expr * not_child = to_app(child)->get_arg(0);
slow_process(save_first && i == 0, not_child, m().mk_not_or_elim(pr, i), d, out_f, out_pr);
}
else {
expr_ref not_child(m());
not_child = m().mk_not(child);
slow_process(save_first && i == 0, not_child, m().mk_not_or_elim(pr, i), d, out_f, out_pr);
}
}
}
void goal::slow_process(bool save_first, expr * f, proof * pr, expr_dependency * d, expr_ref & out_f, proof_ref & out_pr) {
expr* g = nullptr;
proof_ref _pr(pr, m());
if (m().is_and(f))
process_and(save_first, to_app(f), pr, d, out_f, out_pr);
else if (m().is_not(f, g) && m().is_or(g))
process_not_or(save_first, to_app(g), pr, d, out_f, out_pr);
else if (save_first) {
out_f = f;
out_pr = pr;
}
else {
push_back(f, pr, d);
}
}
void goal::slow_process(expr * f, proof * pr, expr_dependency * d) {
expr_ref out_f(m());
proof_ref out_pr(m());
slow_process(false, f, pr, d, out_f, out_pr);
}
void goal::assert_expr(expr * f, proof * pr, expr_dependency * d) {
expr_ref _f(f, m());
proof_ref _pr(pr, m());
expr_dependency_ref _d(d, m());
if (m_inconsistent) {
return;
}
SASSERT(!proofs_enabled() || pr);
if (pr) {
CTRACE("goal", f != m().get_fact(pr), tout << mk_pp(f, m()) << "\n" << mk_pp(pr, m()) << "\n";);
SASSERT(f == m().get_fact(pr));
slow_process(f, pr, d);
}
else {
expr_ref fr(f, m());
quick_process(false, fr, d);
}
}
void goal::assert_expr(expr * f, expr_dependency * d) {
assert_expr(f, proofs_enabled() ? m().mk_asserted(f) : nullptr, d);
}
void goal::get_formulas(ptr_vector & result) const {
unsigned sz = size();
for (unsigned i = 0; i < sz; i++) {
result.push_back(form(i));
}
}
void goal::get_formulas(expr_ref_vector & result) const {
unsigned sz = size();
for (unsigned i = 0; i < sz; i++) {
result.push_back(form(i));
}
}
void goal::update(unsigned i, expr * f, proof * pr, expr_dependency * d) {
if (m_inconsistent)
return;
if (proofs_enabled()) {
SASSERT(pr);
if (!pr)
return;
SASSERT(f == m().get_fact(pr));
expr_ref out_f(m());
proof_ref out_pr(m());
slow_process(true, f, pr, d, out_f, out_pr);
if (!m_inconsistent) {
if (m().is_false(out_f)) {
push_back(out_f, out_pr, d);
}
else {
m().set(m_forms, i, out_f);
m().set(m_proofs, i, out_pr);
if (unsat_core_enabled())
m().set(m_dependencies, i, d);
}
}
}
else {
expr_ref fr(f, m());
quick_process(true, fr, d);
if (!m_inconsistent) {
if (m().is_false(fr)) {
push_back(f, nullptr, d);
}
else {
m().set(m_forms, i, fr);
if (unsat_core_enabled())
m().set(m_dependencies, i, d);
}
}
}
}
void goal::reset_core() {
m().del(m_forms);
m().del(m_proofs);
m().del(m_dependencies);
}
void goal::reset_all() {
reset_core();
m_depth = 0;
m_inconsistent = false;
m_precision = PRECISE;
}
void goal::reset() {
reset_core();
m_inconsistent = false;
}
void goal::display(ast_printer & prn, std::ostream & out) const {
out << "(goal";
unsigned sz = size();
for (unsigned i = 0; i < sz; i++) {
out << "\n ";
prn.display(out, form(i), 2);
}
out << "\n :precision " << prec() << " :depth " << depth() << ")" << std::endl;
}
void goal::display_with_dependencies(ast_printer & prn, std::ostream & out) const {
ptr_vector deps;
obj_hashtable to_pp;
out << "(goal";
unsigned sz = size();
for (unsigned i = 0; i < sz; i++) {
out << "\n |-";
deps.reset();
m().linearize(dep(i), deps);
for (expr * d : deps) {
if (is_uninterp_const(d)) {
out << " " << mk_ismt2_pp(d, m());
}
else {
out << " #" << d->get_id();
to_pp.insert(d);
}
}
out << "\n ";
prn.display(out, form(i), 2);
}
if (!to_pp.empty()) {
out << "\n :dependencies-definitions (";
for (expr* d : to_pp) {
out << "\n (#" << d->get_id() << "\n ";
prn.display(out, d, 2);
out << ")";
}
out << ")";
}
out << "\n :precision " << prec() << " :depth " << depth() << ")" << std::endl;
}
void goal::display_with_dependencies(std::ostream & out) const {
ptr_vector deps;
out << "(goal";
unsigned sz = size();
for (unsigned i = 0; i < sz; i++) {
out << "\n |-";
deps.reset();
m().linearize(dep(i), deps);
for (expr * d : deps) {
if (is_uninterp_const(d)) {
out << " " << mk_ismt2_pp(d, m());
}
else {
out << " #" << d->get_id();
}
}
out << "\n " << mk_ismt2_pp(form(i), m(), 2);
}
out << "\n :precision " << prec() << " :depth " << depth() << ")" << std::endl;
}
void goal::display_with_proofs(std::ostream& out) const {
out << "(goal";
unsigned sz = size();
for (unsigned i = 0; i < sz; i++) {
out << "\n |-";
if (pr(i)) {
out << mk_ismt2_pp(pr(i), m(), 4);
}
out << "\n " << mk_ismt2_pp(form(i), m(), 2);
}
out << "\n :precision " << prec() << " :depth " << depth() << ")" << std::endl;
}
void goal::display(ast_printer_context & ctx) const {
display(ctx, ctx.regular_stream());
}
void goal::display_with_dependencies(ast_printer_context & ctx) const {
display_with_dependencies(ctx, ctx.regular_stream());
}
void goal::display(std::ostream & out) const {
out << "(goal";
unsigned sz = size();
for (unsigned i = 0; i < sz; i++) {
out << "\n ";
out << mk_ismt2_pp(form(i), m(), 2);
}
out << ")" << std::endl;
}
void goal::display_as_and(std::ostream & out) const {
ptr_buffer args;
unsigned sz = size();
for (unsigned i = 0; i < sz; i++)
args.push_back(form(i));
expr_ref tmp(m());
tmp = m().mk_and(args.size(), args.data());
out << mk_ismt2_pp(tmp, m()) << "\n";
}
void goal::display_ll(std::ostream & out) const {
unsigned sz = size();
for (unsigned i = 0; i < sz; i++) {
out << mk_ll_pp(form(i), m()) << "\n";
}
}
/**
\brief Assumes that the formula is already in CNF.
*/
void goal::display_dimacs(std::ostream & out, bool include_names) const {
expr_ref_vector fmls(m());
get_formulas(fmls);
::display_dimacs(out, fmls, include_names);
}
unsigned goal::num_exprs() const {
expr_fast_mark1 visited;
unsigned sz = size();
unsigned r = 0;
for (unsigned i = 0; i < sz; i++) {
r += get_num_exprs(form(i), visited);
}
return r;
}
void goal::shrink(unsigned j) {
SASSERT(j <= size());
unsigned sz = size();
for (unsigned i = j; i < sz; i++)
m().pop_back(m_forms);
for (unsigned i = j; i < sz; i++)
m().pop_back(m_proofs);
if (unsat_core_enabled())
for (unsigned i = j; i < sz; i++)
m().pop_back(m_dependencies);
}
/**
\brief Eliminate true formulas.
*/
void goal::elim_true() {
unsigned sz = size();
unsigned j = 0;
for (unsigned i = 0; i < sz; i++) {
expr * f = form(i);
if (m().is_true(f))
continue;
if (i == j) {
j++;
continue;
}
m().set(m_forms, j, f);
m().set(m_proofs, j, m().get(m_proofs, i));
if (unsat_core_enabled())
m().set(m_dependencies, j, m().get(m_dependencies, i));
j++;
}
shrink(j);
}
/**
\brief Return the position of formula f in the goal.
Return UINT_MAX if f is not in the goal
*/
unsigned goal::get_idx(expr * f) const {
unsigned sz = size();
for (unsigned j = 0; j < sz; j++) {
if (form(j) == f)
return j;
}
return UINT_MAX;
}
/**
\brief Return the position of formula (not f) in the goal.
Return UINT_MAX if (not f) is not in the goal
*/
unsigned goal::get_not_idx(expr * f) const {
expr * atom;
unsigned sz = size();
for (unsigned j = 0; j < sz; j++) {
if (m().is_not(form(j), atom) && atom == f)
return j;
}
return UINT_MAX;
}
void goal::elim_redundancies() {
if (inconsistent())
return;
expr_ref_fast_mark1 neg_lits(m());
expr_ref_fast_mark2 pos_lits(m());
unsigned sz = size();
unsigned j = 0;
for (unsigned i = 0; i < sz; i++) {
expr * f = form(i);
if (m().is_true(f))
continue;
if (m().is_not(f)) {
expr * atom = to_app(f)->get_arg(0);
if (neg_lits.is_marked(atom))
continue;
if (pos_lits.is_marked(atom)) {
proof * p = nullptr;
if (proofs_enabled()) {
proof * prs[2] = { pr(get_idx(atom)), pr(i) };
p = m().mk_unit_resolution(2, prs);
}
expr_dependency_ref d(m());
if (unsat_core_enabled())
d = m().mk_join(dep(get_idx(atom)), dep(i));
push_back(m().mk_false(), p, d);
return;
}
neg_lits.mark(atom);
}
else {
if (pos_lits.is_marked(f))
continue;
if (neg_lits.is_marked(f)) {
proof * p = nullptr;
if (proofs_enabled()) {
proof * prs[2] = { pr(get_not_idx(f)), pr(i) };
p = m().mk_unit_resolution(2, prs);
}
expr_dependency_ref d(m());
if (unsat_core_enabled())
d = m().mk_join(dep(get_not_idx(f)), dep(i));
push_back(m().mk_false(), p, d);
return;
}
pos_lits.mark(f);
}
if (i == j) {
j++;
continue;
}
m().set(m_forms, j, f);
m().set(m_proofs, j, pr(i));
if (unsat_core_enabled())
m().set(m_dependencies, j, dep(i));
j++;
}
shrink(j);
}
bool goal::is_well_formed() const {
unsigned sz = size();
for (unsigned i = 0; i < sz; i++) {
expr * t = form(i);
if (!::is_well_sorted(m(), t))
return false;
#if 0
if (pr(i) && m().get_fact(pr(i)) != form(i)) {
TRACE("tactic", tout << mk_ismt2_pp(pr(i), m()) << "\n" << mk_ismt2_pp(form(i), m()) << "\n";);
SASSERT(m().get_fact(pr(i)) == form(i));
return false;
}
#endif
}
return true;
}
/**
\brief Translate the assertion set to a new one that uses a different ast_manager.
*/
goal * goal::translate(ast_translation & translator) const {
expr_dependency_translation dep_translator(translator);
ast_manager & m_to = translator.to();
goal * res = alloc(goal, m_to, m_to.proofs_enabled() && proofs_enabled(), models_enabled(), unsat_core_enabled());
unsigned sz = m().size(m_forms);
for (unsigned i = 0; i < sz; i++) {
res->m().push_back(res->m_forms, translator(m().get(m_forms, i)));
res->m().push_back(res->m_proofs, translator(m().get(m_proofs, i)));
if (res->unsat_core_enabled())
res->m().push_back(res->m_dependencies, dep_translator(m().get(m_dependencies, i)));
}
res->m_inconsistent = m_inconsistent;
res->m_depth = m_depth;
res->m_precision = m_precision;
res->m_pc = m_pc ? m_pc->translate(translator) : nullptr;
res->m_mc = m_mc ? m_mc->translate(translator) : nullptr;
res->m_dc = m_dc ? m_dc->translate(translator) : nullptr;
return res;
}
bool goal::sat_preserved() const {
return prec() == PRECISE || prec() == UNDER;
}
bool goal::unsat_preserved() const {
return prec() == PRECISE || prec() == OVER;
}
bool goal::is_decided_sat() const {
return size() == 0 && sat_preserved();
}
bool goal::is_decided_unsat() const {
return inconsistent() && unsat_preserved();
}
bool goal::is_decided() const {
return is_decided_sat() || is_decided_unsat();
}
bool is_equal(goal const & s1, goal const & s2) {
if (s1.size() != s2.size())
return false;
unsigned num1 = 0; // num unique ASTs in s1
unsigned num2 = 0; // num unique ASTs in s2
expr_fast_mark1 visited1;
expr_fast_mark2 visited2;
unsigned sz = s1.size();
for (unsigned i = 0; i < sz; i++) {
expr * f1 = s1.form(i);
if (visited1.is_marked(f1))
continue;
num1++;
visited1.mark(f1);
}
SASSERT(num1 <= sz);
SASSERT(0 <= num1);
for (unsigned i = 0; i < sz; i++) {
expr * f2 = s2.form(i);
if (visited2.is_marked(f2))
continue;
num2++;
visited2.mark(f2);
if (!visited1.is_marked(f2))
return false;
}
SASSERT(num2 <= sz);
SASSERT(0 <= num2);
SASSERT(num1 >= num2);
return num1 == num2;
}
bool goal::is_cnf() const {
for (unsigned i = 0; i < size(); i++) {
expr * f = form(i);
if (m_manager.is_or(f)) {
for (expr* lit : *to_app(f))
if (!is_literal(lit))
return false;
}
if (!is_literal(f))
return false;
}
return true;
}
bool goal::is_literal(expr* f) const {
m_manager.is_not(f, f);
if (!is_app(f))
return false;
if (to_app(f)->get_family_id() == m_manager.get_basic_family_id())
for (expr* arg : *to_app(f))
if (m_manager.is_bool(arg))
return false;
return true;
}