z3-z3-4.13.0.src.smt.proto_model.proto_model.cpp Maven / Gradle / Ivy
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/*++
Copyright (c) 2006 Microsoft Corporation
Module Name:
proto_model.cpp
Abstract:
Author:
Leonardo de Moura (leonardo) 2007-03-08.
Revision History:
--*/
#include "ast/ast_pp.h"
#include "ast/ast_ll_pp.h"
#include "ast/well_sorted.h"
#include "ast/array_decl_plugin.h"
#include "ast/used_symbols.h"
#include "ast/for_each_expr.h"
#include "ast/rewriter/var_subst.h"
#include "model/model_params.hpp"
#include "model/model_v2_pp.h"
#include "smt/proto_model/proto_model.h"
proto_model::proto_model(ast_manager & m, params_ref const & p):
model_core(m),
m_eval(*this),
m_rewrite(m) {
register_factory(alloc(basic_factory, m, m.get_num_asts()));
m_user_sort_factory = alloc(user_sort_factory, m);
register_factory(m_user_sort_factory);
m_model_partial = model_params(p).partial();
}
void proto_model::register_aux_decl(func_decl * d, func_interp * fi) {
model_core::register_decl(d, fi);
m_aux_decls.insert(d);
}
void proto_model::register_aux_decl(func_decl * d) {
m_aux_decls.insert(d);
}
/**
\brief Set new_fi as the new interpretation for f.
If f_aux != 0, then assign the old interpretation of f to f_aux.
If f_aux == 0, then delete the old interpretation of f.
f_aux is marked as a auxiliary declaration.
*/
void proto_model::reregister_decl(func_decl * f, func_interp * new_fi, func_decl * f_aux) {
func_interp * fi = get_func_interp(f);
if (fi == nullptr) {
register_decl(f, new_fi);
}
else {
if (f_aux != nullptr) {
register_decl(f_aux, fi);
m_aux_decls.insert(f_aux);
}
else {
dealloc(fi);
}
m_finterp.insert(f, new_fi);
}
}
expr * proto_model::mk_some_interp_for(func_decl * d) {
SASSERT(!has_interpretation(d));
expr * r = get_some_value(d->get_range()); // if t is a function, then it will be the constant function.
if (d->get_arity() == 0) {
register_decl(d, r);
}
else {
func_interp * new_fi = alloc(func_interp, m, d->get_arity());
new_fi->set_else(r);
register_decl(d, new_fi);
}
return r;
}
bool proto_model::eval(expr * e, expr_ref & result, bool model_completion) {
m_eval.set_model_completion(model_completion);
m_eval.set_expand_array_equalities(false);
TRACE("model_evaluator", model_v2_pp(tout, *this, true););
try {
m_eval(e, result);
return true;
}
catch (model_evaluator_exception & ex) {
(void)ex;
TRACE("model_evaluator", tout << ex.msg() << "\n";);
return false;
}
}
/**
\brief Evaluate the expression e in the current model, and store the result in \c result.
It returns \c true if succeeded, and false otherwise. If the evaluation fails,
then r contains a term that is simplified as much as possible using the interpretations
available in the model.
When model_completion == true, if the model does not assign an interpretation to a
declaration it will build one for it. Moreover, partial functions will also be completed.
So, if model_completion == true, the evaluator never fails if it doesn't contain quantifiers.
*/
/**
\brief Replace uninterpreted constants occurring in fi->get_else()
by their interpretations.
*/
void proto_model::cleanup_func_interp(expr_ref_vector& trail, func_interp * fi, func_decl_set & found_aux_fs) {
if (!fi->is_partial()) {
expr * fi_else = fi->get_else();
fi->set_else(cleanup_expr(trail, fi_else, found_aux_fs));
}
}
expr* proto_model::cleanup_expr(expr_ref_vector& trail, expr* fi_else, func_decl_set& found_aux_fs) {
TRACE("model_bug", tout << "cleaning up:\n" << mk_pp(fi_else, m) << "\n";);
trail.reset();
obj_map cache;
ptr_buffer todo;
ptr_buffer args;
todo.push_back(fi_else);
expr * a;
expr_ref new_t(m);
while (!todo.empty()) {
a = todo.back();
if (is_uninterp_const(a)) {
todo.pop_back();
func_decl * a_decl = to_app(a)->get_decl();
expr * ai = get_const_interp(a_decl);
if (ai == nullptr) {
ai = get_some_value(a_decl->get_range());
register_decl(a_decl, ai);
}
cache.insert(a, ai);
}
else {
switch(a->get_kind()) {
case AST_APP: {
app * t = to_app(a);
bool visited = true;
args.reset();
for (expr* t_arg : *t) {
expr * arg = nullptr;
if (!cache.find(t_arg, arg)) {
visited = false;
todo.push_back(t_arg);
}
else {
args.push_back(arg);
}
}
if (!visited) {
continue;
}
func_decl * f = t->get_decl();
if (m_aux_decls.contains(f)) {
TRACE("model_bug", tout << f->get_name() << "\n";);
found_aux_fs.insert(f);
}
new_t = m_rewrite.mk_app(f, args.size(), args.data());
if (t != new_t.get())
trail.push_back(new_t);
todo.pop_back();
cache.insert(t, new_t);
break;
}
default:
SASSERT(a != nullptr);
cache.insert(a, a);
todo.pop_back();
break;
}
}
}
VERIFY(cache.find(fi_else, a));
return a;
}
void proto_model::remove_aux_decls_not_in_set(ptr_vector & decls, func_decl_set const & s) {
unsigned j = 0;
for (func_decl* f : decls) {
if (!m_aux_decls.contains(f) || s.contains(f)) {
decls[j++] = f;
}
}
decls.shrink(j);
}
/**
\brief Replace uninterpreted constants occurring in the func_interp's get_else()
by their interpretations.
*/
void proto_model::cleanup() {
TRACE("model_bug", model_v2_pp(tout, *this););
func_decl_set found_aux_fs;
expr_ref_vector trail(m);
ptr_buffer finterps;
for (auto const& kv : m_finterp)
finterps.push_back(kv.m_value);
for (auto* fi : finterps)
cleanup_func_interp(trail, fi, found_aux_fs);
for (unsigned i = 0; i < m_const_decls.size(); ++i) {
func_decl* d = m_const_decls[i];
expr* e = m_interp[d].second;
expr* r = cleanup_expr(trail, e, found_aux_fs);
if (e != r) {
register_decl(d, r);
}
}
// TRACE("model_bug", model_v2_pp(tout, *this););
// remove auxiliary declarations that are not used.
if (found_aux_fs.size() != m_aux_decls.size()) {
remove_aux_decls_not_in_set(m_decls, found_aux_fs);
remove_aux_decls_not_in_set(m_func_decls, found_aux_fs);
for (func_decl* faux : m_aux_decls) {
if (!found_aux_fs.contains(faux)) {
TRACE("cleanup_bug", tout << "eliminating " << faux->get_name() << " " << faux->get_ref_count() << "\n";);
unregister_decl(faux);
}
}
m_aux_decls.swap(found_aux_fs);
}
TRACE("model_bug", model_v2_pp(tout, *this););
}
value_factory * proto_model::get_factory(family_id fid) {
return m_factories.get_plugin(fid);
}
void proto_model::freeze_universe(sort * s) {
SASSERT(m.is_uninterp(s));
m_user_sort_factory->freeze_universe(s);
}
/**
\brief Return the known universe of an uninterpreted sort.
*/
obj_hashtable const & proto_model::get_known_universe(sort * s) const {
return m_user_sort_factory->get_known_universe(s);
}
ptr_vector const & proto_model::get_universe(sort * s) const {
ptr_vector & tmp = const_cast(this)->m_tmp;
tmp.reset();
obj_hashtable const & u = get_known_universe(s);
for (expr * e : u) {
tmp.push_back(e);
}
return tmp;
}
unsigned proto_model::get_num_uninterpreted_sorts() const {
return m_user_sort_factory->get_num_sorts();
}
sort * proto_model::get_uninterpreted_sort(unsigned idx) const {
SASSERT(idx < get_num_uninterpreted_sorts());
return m_user_sort_factory->get_sort(idx);
}
/**
\brief Return true if the given sort is uninterpreted and has a finite interpretation
in the model.
*/
bool proto_model::is_finite(sort * s) const {
return m.is_uninterp(s) && m_user_sort_factory->is_finite(s);
}
expr * proto_model::get_some_value(sort * s) {
if (m.is_uninterp(s))
return m_user_sort_factory->get_some_value(s);
else if (value_factory * f = get_factory(s->get_family_id()))
return f->get_some_value(s);
else
// there is no factory for the family id, then assume s is uninterpreted.
return m_user_sort_factory->get_some_value(s);
}
bool proto_model::get_some_values(sort * s, expr_ref & v1, expr_ref & v2) {
if (m.is_uninterp(s))
return m_user_sort_factory->get_some_values(s, v1, v2);
else if (value_factory * f = get_factory(s->get_family_id()))
return f->get_some_values(s, v1, v2);
else
return false;
}
expr * proto_model::get_fresh_value(sort * s) {
if (m.is_uninterp(s))
return m_user_sort_factory->get_fresh_value(s);
else if (value_factory * f = get_factory(s->get_family_id()))
return f->get_fresh_value(s);
else
// Use user_sort_factory if the theory has no support for model construnction.
// This is needed when dummy theories are used for arithmetic or arrays.
return m_user_sort_factory->get_fresh_value(s);
}
void proto_model::register_value(expr * n) {
sort * s = n->get_sort();
if (m.is_uninterp(s)) {
m_user_sort_factory->register_value(n);
}
else {
family_id fid = s->get_family_id();
value_factory * f = get_factory(fid);
if (f)
f->register_value(n);
}
}
void proto_model::compress() {
for (func_decl* f : m_func_decls) {
func_interp * fi = get_func_interp(f);
SASSERT(fi != nullptr);
fi->compress();
}
}
/**
\brief Complete the interpretation fi of f if it is partial.
If f does not have an interpretation in the given model, then this is a noop.
*/
void proto_model::complete_partial_func(func_decl * f, bool use_fresh) {
func_interp * fi = get_func_interp(f);
if (fi && fi->is_partial()) {
expr * else_value;
if (use_fresh) {
else_value = get_fresh_value(f->get_range());
}
else {
else_value = fi->get_max_occ_result();
}
if (else_value == nullptr)
else_value = get_some_value(f->get_range());
fi->set_else(else_value);
}
}
/**
\brief Set the (else) field of function interpretations...
*/
void proto_model::complete_partial_funcs(bool use_fresh) {
if (m_model_partial)
return;
// m_func_decls may be "expanded" when we invoke get_some_value.
// So, we must not use iterators to traverse it.
for (unsigned i = 0; i < m_func_decls.size(); ++i) {
complete_partial_func(m_func_decls.get(i), use_fresh);
}
}
model * proto_model::mk_model() {
TRACE("proto_model", model_v2_pp(tout << "mk_model\n", *this););
model * mdl = alloc(model, m);
for (auto const& kv : m_interp) {
mdl->register_decl(kv.m_key, kv.m_value.second);
}
for (auto const& kv : m_finterp) {
mdl->register_decl(kv.m_key, kv.m_value);
m.dec_ref(kv.m_key);
}
m_finterp.reset(); // m took the ownership of the func_interp's
unsigned sz = get_num_uninterpreted_sorts();
for (unsigned i = 0; i < sz; i++) {
sort * s = get_uninterpreted_sort(i);
TRACE("proto_model", tout << "copying uninterpreted sorts...\n" << mk_pp(s, m) << "\n";);
ptr_vector const& buf = get_universe(s);
mdl->register_usort(s, buf.size(), buf.data());
}
return mdl;
}