mirror of
https://github.com/Z3Prover/z3
synced 2026-06-13 20:35:39 +00:00
251 lines
7.9 KiB
C++
251 lines
7.9 KiB
C++
|
|
/*++
|
|
Copyright (c) 2025 Microsoft Corporation
|
|
|
|
Module Name:
|
|
|
|
mbp_qel.cpp
|
|
|
|
Abstract:
|
|
|
|
Unit tests for model-based projection with QEL (term-graph based)
|
|
|
|
Author:
|
|
|
|
Hari Govind V K (hgvk94) 2025-05-25
|
|
|
|
--*/
|
|
|
|
#include "qe/qe_mbp.h"
|
|
#include "ast/reg_decl_plugins.h"
|
|
#include "ast/datatype_decl_plugin.h"
|
|
#include "ast/arith_decl_plugin.h"
|
|
#include "ast/ast_pp.h"
|
|
#include "smt/smt_context.h"
|
|
#include "params/smt_params.h"
|
|
#include <iostream>
|
|
|
|
// Test that MBP with QEL does not return false for a satisfiable formula
|
|
// involving datatype accessors applied past the end of a list.
|
|
//
|
|
// Formula: (and ((_ is cons) x) ((_ is nil) (tl x)) (= nil (tl (tl x))) (< 8 n))
|
|
// Project: x
|
|
// Expected: result should imply n >= 9 (and model should satisfy it)
|
|
// Bug: QEL was returning false because rm_accessor unconditionally
|
|
// assumed (tl x) has constructor cons when eliminating (tl (tl x)),
|
|
// contradicting the ((_ is nil) (tl x)) literal.
|
|
static void test_dt_accessor_past_end() {
|
|
std::cout << "test_dt_accessor_past_end\n";
|
|
ast_manager m;
|
|
reg_decl_plugins(m);
|
|
datatype_util dt(m);
|
|
arith_util a(m);
|
|
|
|
// Create list datatype: (declare-datatypes ((L 0)) (((cons (hd Int) (tl L)) (nil))))
|
|
sort_ref int_sort(a.mk_int(), m);
|
|
func_decl_ref cons(m), is_cons(m), head(m), tail(m), nil(m), is_nil(m);
|
|
sort_ref L = dt.mk_list_datatype(int_sort, symbol("L"),
|
|
cons, is_cons, head, tail, nil, is_nil);
|
|
|
|
// Declare variables
|
|
app_ref x(m.mk_const("x", L), m);
|
|
app_ref n(m.mk_const("n", int_sort), m);
|
|
|
|
// Build formula: (and ((_ is cons) x) ((_ is nil) (tl x)) (= nil (tl (tl x))) (< 8 n))
|
|
expr_ref tl_x(m.mk_app(tail, x.get()), m);
|
|
expr_ref tl_tl_x(m.mk_app(tail, tl_x.get()), m);
|
|
expr_ref nil_val(m.mk_const(nil), m);
|
|
|
|
expr_ref is_cons_x(m.mk_app(is_cons, x.get()), m);
|
|
expr_ref is_nil_tl_x(m.mk_app(is_nil, tl_x.get()), m);
|
|
expr_ref eq_nil_tl_tl_x(m.mk_eq(nil_val, tl_tl_x), m);
|
|
expr_ref lt_8_n(a.mk_lt(a.mk_int(8), n), m);
|
|
|
|
expr_ref_vector conjs(m);
|
|
conjs.push_back(is_cons_x).push_back(is_nil_tl_x).push_back(eq_nil_tl_tl_x).push_back(lt_8_n);
|
|
expr_ref fml(m.mk_and(conjs), m);
|
|
|
|
std::cout << " formula:\n " << mk_pp(fml, m, 5) << "\n";
|
|
|
|
// Get a model
|
|
smt_params params;
|
|
params.m_model = true;
|
|
model_ref mdl;
|
|
{
|
|
smt::context ctx(m, params);
|
|
ctx.assert_expr(fml);
|
|
lbool result = ctx.check();
|
|
VERIFY(result == l_true);
|
|
ctx.get_model(mdl);
|
|
}
|
|
|
|
std::cout << " model: x = " << mk_pp((*mdl)(x), m)
|
|
<< ", n = " << mk_pp((*mdl)(n), m) << "\n";
|
|
|
|
// Call MBP with QEL enabled
|
|
app_ref_vector vars(m);
|
|
vars.push_back(x);
|
|
|
|
params_ref p;
|
|
p.set_bool("qsat_use_qel", true);
|
|
qe::mbproj mbp(m, p);
|
|
expr_ref projected(fml, m);
|
|
mbp.spacer(vars, *mdl.get(), projected);
|
|
|
|
std::cout << " projected (qel=true):\n " << mk_pp(projected, m, 5) << "\n";
|
|
|
|
// The result must not be false
|
|
VERIFY(!m.is_false(projected));
|
|
|
|
// The model should satisfy the projected formula
|
|
VERIFY(mdl->is_true(projected));
|
|
|
|
// x should have been eliminated
|
|
VERIFY(vars.empty());
|
|
|
|
std::cout << " PASS\n\n";
|
|
}
|
|
|
|
// Same test but with a deeper list structure:
|
|
// x is a 2-element list with a past-end accessor constraint
|
|
// Formula: (and ((_ is cons) x) ((_ is cons) (tl x)) ((_ is nil) (tl (tl x)))
|
|
// (= nil (tl (tl (tl x)))) (< 8 n))
|
|
static void test_dt_accessor_past_end_depth2() {
|
|
std::cout << "test_dt_accessor_past_end_depth2\n";
|
|
ast_manager m;
|
|
reg_decl_plugins(m);
|
|
datatype_util dt(m);
|
|
arith_util a(m);
|
|
|
|
sort_ref int_sort(a.mk_int(), m);
|
|
func_decl_ref cons(m), is_cons(m), head(m), tail(m), nil(m), is_nil(m);
|
|
sort_ref L = dt.mk_list_datatype(int_sort, symbol("L"),
|
|
cons, is_cons, head, tail, nil, is_nil);
|
|
|
|
app_ref x(m.mk_const("x", L), m);
|
|
app_ref n(m.mk_const("n", int_sort), m);
|
|
|
|
// Build: (and (is-cons x) (is-cons (tl x)) (is-nil (tl (tl x)))
|
|
// (= nil (tl (tl (tl x)))) (< 8 n))
|
|
expr_ref tl_x(m.mk_app(tail, x.get()), m);
|
|
expr_ref tl_tl_x(m.mk_app(tail, tl_x.get()), m);
|
|
expr_ref tl_tl_tl_x(m.mk_app(tail, tl_tl_x.get()), m);
|
|
expr_ref nil_val(m.mk_const(nil), m);
|
|
|
|
expr_ref is_cons_x(m.mk_app(is_cons, x.get()), m);
|
|
expr_ref is_cons_tl_x(m.mk_app(is_cons, tl_x.get()), m);
|
|
expr_ref is_nil_tl_tl_x(m.mk_app(is_nil, tl_tl_x.get()), m);
|
|
expr_ref eq_nil_tl3(m.mk_eq(nil_val, tl_tl_tl_x), m);
|
|
expr_ref lt_8_n(a.mk_lt(a.mk_int(8), n), m);
|
|
|
|
expr_ref_vector conjs(m);
|
|
conjs.push_back(is_cons_x).push_back(is_cons_tl_x).push_back(is_nil_tl_tl_x).push_back(eq_nil_tl3).push_back(lt_8_n);
|
|
expr_ref fml(m.mk_and(conjs), m);
|
|
|
|
std::cout << " formula:\n " << mk_pp(fml, m, 5) << "\n";
|
|
|
|
smt_params sparams;
|
|
sparams.m_model = true;
|
|
model_ref mdl;
|
|
{
|
|
smt::context ctx(m, sparams);
|
|
ctx.assert_expr(fml);
|
|
lbool result = ctx.check();
|
|
VERIFY(result == l_true);
|
|
ctx.get_model(mdl);
|
|
}
|
|
|
|
std::cout << " model: x = " << mk_pp((*mdl)(x), m)
|
|
<< ", n = " << mk_pp((*mdl)(n), m) << "\n";
|
|
|
|
app_ref_vector vars(m);
|
|
vars.push_back(x);
|
|
|
|
params_ref p;
|
|
p.set_bool("qsat_use_qel", true);
|
|
qe::mbproj mbp(m, p);
|
|
expr_ref projected(fml, m);
|
|
mbp.spacer(vars, *mdl.get(), projected);
|
|
|
|
std::cout << " projected (qel=true):\n " << mk_pp(projected, m, 5) << "\n";
|
|
|
|
VERIFY(!m.is_false(projected));
|
|
VERIFY(mdl->is_true(projected));
|
|
VERIFY(vars.empty());
|
|
|
|
std::cout << " PASS\n\n";
|
|
}
|
|
|
|
// Test with multiple DT variables projected simultaneously
|
|
// Formula: (and (= nil (tl (tl (tl x)))) ((_ is nil) (tl (tl x)))
|
|
// ((_ is cons) y) ((_ is nil) (tl y)) (< 8 n))
|
|
// Project: x, y
|
|
static void test_dt_multiple_vars() {
|
|
std::cout << "test_dt_multiple_vars\n";
|
|
ast_manager m;
|
|
reg_decl_plugins(m);
|
|
datatype_util dt(m);
|
|
arith_util a(m);
|
|
|
|
sort_ref int_sort(a.mk_int(), m);
|
|
func_decl_ref cons(m), is_cons(m), head(m), tail(m), nil(m), is_nil(m);
|
|
sort_ref L = dt.mk_list_datatype(int_sort, symbol("L"),
|
|
cons, is_cons, head, tail, nil, is_nil);
|
|
|
|
app_ref x(m.mk_const("x", L), m);
|
|
app_ref y(m.mk_const("y", L), m);
|
|
app_ref n(m.mk_const("n", int_sort), m);
|
|
|
|
expr_ref tl_x(m.mk_app(tail, x.get()), m);
|
|
expr_ref tl_tl_x(m.mk_app(tail, tl_x.get()), m);
|
|
expr_ref tl_tl_tl_x(m.mk_app(tail, tl_tl_x.get()), m);
|
|
expr_ref tl_y(m.mk_app(tail, y.get()), m);
|
|
expr_ref nil_val(m.mk_const(nil), m);
|
|
|
|
expr_ref eq_nil_tl3x(m.mk_eq(nil_val, tl_tl_tl_x), m);
|
|
expr_ref is_nil_tl2x(m.mk_app(is_nil, tl_tl_x.get()), m);
|
|
expr_ref is_cons_y(m.mk_app(is_cons, y.get()), m);
|
|
expr_ref is_nil_tl_y(m.mk_app(is_nil, tl_y.get()), m);
|
|
expr_ref lt_8_n(a.mk_lt(a.mk_int(8), n), m);
|
|
|
|
expr_ref_vector conjs(m);
|
|
conjs.push_back(eq_nil_tl3x).push_back(is_nil_tl2x).push_back(is_cons_y).push_back(is_nil_tl_y).push_back(lt_8_n);
|
|
expr_ref fml(m.mk_and(conjs), m);
|
|
|
|
std::cout << " formula:\n " << mk_pp(fml, m, 5) << "\n";
|
|
|
|
smt_params sparams;
|
|
sparams.m_model = true;
|
|
model_ref mdl;
|
|
{
|
|
smt::context ctx(m, sparams);
|
|
ctx.assert_expr(fml);
|
|
lbool result = ctx.check();
|
|
VERIFY(result == l_true);
|
|
ctx.get_model(mdl);
|
|
}
|
|
|
|
app_ref_vector vars(m);
|
|
vars.push_back(x);
|
|
vars.push_back(y);
|
|
|
|
params_ref p;
|
|
p.set_bool("qsat_use_qel", true);
|
|
qe::mbproj mbp(m, p);
|
|
expr_ref projected(fml, m);
|
|
mbp.spacer(vars, *mdl.get(), projected);
|
|
|
|
std::cout << " projected (qel=true):\n " << mk_pp(projected, m, 5) << "\n";
|
|
|
|
VERIFY(!m.is_false(projected));
|
|
VERIFY(mdl->is_true(projected));
|
|
VERIFY(vars.empty());
|
|
|
|
std::cout << " PASS\n\n";
|
|
}
|
|
|
|
void tst_mbp_qel() {
|
|
test_dt_accessor_past_end();
|
|
test_dt_accessor_past_end_depth2();
|
|
test_dt_multiple_vars();
|
|
}
|