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/*++
Copyright (c) 2006 Microsoft Corporation
Module Name:
ast_util.cpp
Abstract:
Helper functions
Author:
Leonardo de Moura (leonardo) 2007-06-08.
Revision History:
--*/
#include "ast/ast_util.h"
#include "ast/ast_pp.h"
#include "ast/for_each_expr.h"
#include "ast/arith_decl_plugin.h"
app * mk_list_assoc_app(ast_manager & m, func_decl * f, unsigned num_args, expr * const * args) {
SASSERT(f->is_associative());
SASSERT(num_args >= 2);
if (num_args > 2) {
unsigned j = num_args - 1;
app * r = m.mk_app(f, args[j-1], args[j]);
-- j;
while (j > 0) {
--j;
r = m.mk_app(f, args[j], r);
}
return r;
}
else {
SASSERT(num_args == 2);
return m.mk_app(f, args[0], args[1]);
}
}
app * mk_list_assoc_app(ast_manager & m, family_id fid, decl_kind k, unsigned num_args, expr * const * args) {
func_decl * decl = m.mk_func_decl(fid, k, 0, nullptr, num_args, args, nullptr);
SASSERT(decl != 0);
SASSERT(decl->is_associative());
return mk_list_assoc_app(m, decl, num_args, args);
}
bool is_well_formed_vars(ptr_vector& bound, expr * top) {
ptr_vector todo;
ast_mark mark;
todo.push_back(top);
while (!todo.empty()) {
expr * e = todo.back();
todo.pop_back();
if (mark.is_marked(e)) {
continue;
}
mark.mark(e, true);
if (is_quantifier(e)) {
quantifier* q = to_quantifier(e);
unsigned depth = q->get_num_decls();
bound.append(depth, q->get_decl_sorts());
if (!is_well_formed_vars(bound, q->get_expr())) {
return false;
}
bound.resize(bound.size()-depth);
}
else if (is_app(e)) {
app* a = to_app(e);
for (unsigned i = 0; i < a->get_num_args(); ++i) {
todo.push_back(a->get_arg(i));
}
}
else if (is_var(e)) {
var* v = to_var(e);
unsigned index = v->get_idx();
sort* s = v->get_sort();
SASSERT(index < bound.size());
index = bound.size()-1-index;
if (!bound[index]) {
bound[index] = s;
}
if (bound[index] != s) {
return false;
}
}
else {
UNREACHABLE();
}
}
return true;
}
bool is_atom(ast_manager & m, expr * n) {
if (is_quantifier(n) || !m.is_bool(n))
return false;
if (is_var(n))
return true;
SASSERT(is_app(n));
if (to_app(n)->get_family_id() != m.get_basic_family_id()) {
return true;
}
// the other operators of the basic family are not considered atomic: distinct, ite, and, or, iff, xor, not, implies.
return (m.is_eq(n) && !m.is_bool(to_app(n)->get_arg(0))) || m.is_true(n) || m.is_false(n);
}
bool is_literal(ast_manager & m, expr * n) {
return
is_atom(m, n) ||
(m.is_not(n) && is_atom(m, to_app(n)->get_arg(0)));
}
void get_literal_atom_sign(ast_manager & m, expr * n, expr * & atom, bool & sign) {
SASSERT(is_literal(m, n));
if (is_atom(m, n)) {
atom = n;
sign = false;
}
else {
SASSERT(m.is_not(n));
atom = to_app(n)->get_arg(0);
sign = true;
}
}
bool is_clause(ast_manager & m, expr * n) {
if (is_literal(m, n))
return true;
if (m.is_or(n)) {
for (expr* arg : *to_app(n))
if (!is_literal(m, arg))
return false;
return true;
}
return false;
}
unsigned get_clause_num_literals(ast_manager & m, expr * cls) {
SASSERT(is_clause(m, cls));
if (is_literal(m, cls))
return 1;
SASSERT(m.is_or(cls));
return to_app(cls)->get_num_args();
}
expr * get_clause_literal(ast_manager & m, expr * cls, unsigned idx) {
SASSERT(is_clause(m, cls));
SASSERT(idx < get_clause_num_literals(m, cls));
if (is_literal(m, cls)) {
SASSERT(idx == 0);
return cls;
}
SASSERT(m.is_or(cls));
return to_app(cls)->get_arg(idx);
}
expr * mk_and(ast_manager & m, unsigned num_args, expr * const * args) {
if (num_args == 0)
return m.mk_true();
else if (num_args == 1)
return args[0];
else
return m.mk_and(num_args, args);
}
app* mk_and(ast_manager & m, unsigned num_args, app * const * args) {
return to_app(mk_and(m, num_args, (expr* const*) args));
}
expr * mk_or(ast_manager & m, unsigned num_args, expr * const * args) {
if (num_args == 0)
return m.mk_false();
else if (num_args == 1)
return args[0];
else
return m.mk_or(num_args, args);
}
app* mk_or(ast_manager & m, unsigned num_args, app * const * args) {
return to_app(mk_or(m, num_args, (expr* const*) args));
}
expr * mk_not(ast_manager & m, expr * arg) {
expr * atom;
if (m.is_not(arg, atom))
return atom;
else if (m.is_true(arg))
return m.mk_false();
else if (m.is_false(arg))
return m.mk_true();
else
return m.mk_not(arg);
}
expr_ref mk_not(const expr_ref& e) {
return expr_ref(mk_not(e.m(), e), e.m());
}
expr_ref push_not(const expr_ref& e, unsigned limit) {
ast_manager& m = e.get_manager();
if (!is_app(e) || limit == 0) {
return mk_not(e);
}
app* a = to_app(e);
if (m.is_and(a)) {
if (a->get_num_args() == 0) {
return expr_ref(m.mk_false(), m);
}
expr_ref_vector args(m);
for (expr* arg : *a) {
args.push_back(push_not(expr_ref(arg, m), limit-1));
}
return mk_or(args);
}
if (m.is_or(a)) {
if (a->get_num_args() == 0) {
return expr_ref(m.mk_true(), m);
}
expr_ref_vector args(m);
for (expr* arg : *a) {
args.push_back(push_not(expr_ref(arg, m), limit-1));
}
return mk_and(args);
}
return mk_not(e);
}
expr * expand_distinct(ast_manager & m, unsigned num_args, expr * const * args) {
expr_ref_buffer new_diseqs(m);
for (unsigned i = 0; i < num_args; i++) {
for (unsigned j = i + 1; j < num_args; j++)
new_diseqs.push_back(m.mk_not(m.mk_eq(args[i], args[j])));
}
return mk_and(m, new_diseqs.size(), new_diseqs.data());
}
expr* mk_distinct(ast_manager& m, unsigned num_args, expr * const * args) {
switch (num_args) {
case 0:
case 1:
return m.mk_true();
case 2:
return m.mk_not(m.mk_eq(args[0], args[1]));
default:
return m.mk_distinct(num_args, args);
}
}
expr_ref mk_distinct(expr_ref_vector const& args) {
ast_manager& m = args.get_manager();
return expr_ref(mk_distinct(m, args.size(), args.data()), m);
}
void flatten_and(expr_ref_vector& result) {
ast_manager& m = result.get_manager();
expr* e1, *e2, *e3;
expr_ref_vector pin(m);
expr_fast_mark1 seen;
for (unsigned i = 0; i < result.size(); ++i) {
expr* e = result.get(i);
if (seen.is_marked(e)) {
result[i] = result.back();
result.pop_back();
--i;
continue;
}
seen.mark(e);
pin.push_back(e);
if (m.is_and(e)) {
app* a = to_app(e);
for (expr* arg : *a)
result.push_back(arg);
result[i] = result.back();
result.pop_back();
--i;
}
else if (m.is_not(e, e1) && m.is_not(e1, e2)) {
result[i] = e2;
--i;
}
else if (m.is_not(e, e1) && m.is_or(e1)) {
app* a = to_app(e1);
for (expr* arg : *a)
result.push_back(mk_not(m, arg));
result[i] = result.back();
result.pop_back();
--i;
}
else if (m.is_not(e, e1) && m.is_implies(e1, e2, e3)) {
result.push_back(e2);
result[i] = mk_not(m, e3);
--i;
}
else if (m.is_true(e) ||
(m.is_not(e, e1) &&
m.is_false(e1))) {
result[i] = result.back();
result.pop_back();
--i;
}
else if (m.is_false(e) ||
(m.is_not(e, e1) &&
m.is_true(e1))) {
result.reset();
result.push_back(m.mk_false());
return;
}
}
}
void flatten_and(expr* fml, expr_ref_vector& result) {
SASSERT(result.get_manager().is_bool(fml));
result.push_back(fml);
flatten_and(result);
}
void flatten_and(expr_ref& fml) {
expr_ref_vector fmls(fml.get_manager());
fmls.push_back(fml);
flatten_and(fmls);
fml = mk_and(fmls);
}
void flatten_or(expr_ref_vector& result) {
ast_manager& m = result.get_manager();
expr* e1, *e2, *e3;
expr_ref_vector pin(m);
expr_fast_mark1 seen;
for (unsigned i = 0; i < result.size(); ++i) {
expr* e = result.get(i);
if (seen.is_marked(e)) {
result[i] = result.back();
result.pop_back();
--i;
continue;
}
seen.mark(e);
pin.push_back(e);
if (m.is_or(e)) {
app* a = to_app(e);
for (expr* arg : *a)
result.push_back(arg);
result[i] = result.back();
result.pop_back();
--i;
}
else if (m.is_not(e, e1) && m.is_not(e1, e2)) {
result[i] = e2;
--i;
}
else if (m.is_not(e, e1) && m.is_and(e1)) {
app* a = to_app(e1);
for (expr* arg : *a)
result.push_back(mk_not(m, arg));
result[i] = result.back();
result.pop_back();
--i;
}
else if (m.is_implies(e,e2,e3)) {
result.push_back(e3);
result[i] = mk_not(m, e2);
--i;
}
else if (m.is_false(e) ||
(m.is_not(e, e1) &&
m.is_true(e1))) {
result[i] = result.back();
result.pop_back();
--i;
}
else if (m.is_true(e) ||
(m.is_not(e, e1) &&
m.is_false(e1))) {
result.reset();
result.push_back(m.mk_true());
return;
}
}
}
void flatten_or(expr* fml, expr_ref_vector& result) {
SASSERT(result.get_manager().is_bool(fml));
result.push_back(fml);
flatten_or(result);
}
static app_ref plus(ast_manager& m, expr* a, expr* b) {
arith_util arith(m);
return app_ref(arith.mk_add(a, b), m);
}
app_ref operator+(expr_ref& a, expr_ref& b) {
return plus(a.m(), a.get(), b.get());
}
bool has_uninterpreted(ast_manager& m, expr* _e) {
expr_ref e(_e, m);
arith_util au(m);
func_decl_ref f_out(m);
for (expr* arg : subterms::all(e)) {
if (!is_app(arg))
continue;
app* a = to_app(arg);
func_decl* f = a->get_decl();
if (a->get_num_args() == 0)
continue;
if (m.is_considered_uninterpreted(f))
return true;
if (au.is_considered_uninterpreted(f, a->get_num_args(), a->get_args(), f_out))
return true;
}
return false;
}