mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2026-04-03 02:18:58 +00:00
Code Activity

Added right-to-left rules

Browse source
This commit is contained in:
CEisenhofer 2026-03-13 17:25:14 +01:00
parent ff6534b53e
commit e384e8f3d4
8 changed files with 817 additions and 578 deletions
Download patch file Download diff file Expand all files Collapse all files

120
src/test/seq_nielsen.cpp
View file

@ -731,6 +731,56 @@ static void test_const_nielsen_priority_over_eq_split() {
SASSERT(root->outgoing().size() == 2);
}
// test const_nielsen tail direction: x·A = w·y
// forward heads are vars (x,w), so forward const_nielsen doesn't apply.
// backward tails are char/var (A,y), so RTL const_nielsen must fire.
static void test_const_nielsen_tail_char_var() {
std::cout << "test_const_nielsen_tail_char_var\n";
ast_manager m;
reg_decl_plugins(m);
euf::egraph eg(m);
euf::sgraph sg(m, eg);
dummy_simple_solver solver;
seq::nielsen_graph ng(sg, solver);
euf::snode* x = sg.mk_var(symbol("x"));
euf::snode* w = sg.mk_var(symbol("w"));
euf::snode* y = sg.mk_var(symbol("y"));
euf::snode* a = sg.mk_char('A');
euf::snode* lhs = sg.mk_concat(x, a); // x·A
euf::snode* rhs = sg.mk_concat(w, y); // w·y
ng.add_str_eq(lhs, rhs);
seq::nielsen_node* root = ng.root();
bool extended = ng.generate_extensions(root);
SASSERT(extended);
SASSERT(root->outgoing().size() == 2);
bool saw_empty = false;
bool saw_tail = false;
for (seq::nielsen_edge* e : root->outgoing()) {
SASSERT(e->subst().size() == 1);
seq::nielsen_subst const& s = e->subst()[0];
SASSERT(s.m_var == y);
if (s.m_replacement && s.m_replacement->is_empty()) {
saw_empty = true;
SASSERT(e->is_progress());
}
else {
euf::snode_vector toks;
s.m_replacement->collect_tokens(toks);
SASSERT(toks.size() == 2);
SASSERT(toks[0]->is_var() && toks[0]->id() == y->id());
SASSERT(toks[1]->is_char() && toks[1]->id() == a->id());
saw_tail = true;
SASSERT(!e->is_progress());
}
}
SASSERT(saw_empty && saw_tail);
}
// test: both sides start with vars → var_nielsen (3 children), not const_nielsen
static void test_const_nielsen_not_applicable_both_vars() {
std::cout << "test_const_nielsen_not_applicable_both_vars\n";
@ -1606,6 +1656,35 @@ static void test_simplify_prefix_cancel() {
SASSERT(node->str_eqs()[0].m_rhs->is_var());
}
// test simplify_and_init: suffix cancellation of matching chars (RTL)
static void test_simplify_suffix_cancel_rtl() {
std::cout << "test_simplify_suffix_cancel_rtl\n";
ast_manager m;
reg_decl_plugins(m);
euf::egraph eg(m);
euf::sgraph sg(m, eg);
dummy_simple_solver solver;
seq::nielsen_graph ng(sg, solver);
euf::snode* a = sg.mk_char('A');
euf::snode* x = sg.mk_var(symbol("x"));
euf::snode* y = sg.mk_var(symbol("y"));
// x·A = y·A → suffix cancel A (RTL) → x = y
euf::snode* xa = sg.mk_concat(x, a);
euf::snode* ya = sg.mk_concat(y, a);
seq::nielsen_node* node = ng.mk_node();
seq::dep_tracker dep; dep.insert(0);
node->add_str_eq(seq::str_eq(xa, ya, dep));
auto sr = node->simplify_and_init(ng);
SASSERT(sr == seq::simplify_result::proceed);
SASSERT(node->str_eqs().size() == 1);
SASSERT(node->str_eqs()[0].m_lhs->is_var());
SASSERT(node->str_eqs()[0].m_rhs->is_var());
}
// test simplify_and_init: symbol clash at first position
static void test_simplify_symbol_clash() {
std::cout << "test_simplify_symbol_clash\n";
@ -1831,6 +1910,44 @@ static void test_simplify_brzozowski_sat() {
SASSERT(sr == seq::simplify_result::satisfied);
}
// test simplify_and_init: backward Brzozowski consumes a trailing char (RTL)
static void test_simplify_brzozowski_rtl_suffix() {
std::cout << "test_simplify_brzozowski_rtl_suffix\n";
ast_manager m;
reg_decl_plugins(m);
euf::egraph eg(m);
euf::sgraph sg(m, eg);
seq_util seq(m);
dummy_simple_solver solver; seq::nielsen_graph ng(sg, solver);
euf::snode* x = sg.mk_var(symbol("x"));
euf::snode* a = sg.mk_char('A');
euf::snode* xa = sg.mk_concat(x, a);
euf::snode* e = sg.mk_empty();
expr_ref ch_b(seq.str.mk_char('B'), m);
expr_ref unit_b(seq.str.mk_unit(ch_b), m);
expr_ref ch_a(seq.str.mk_char('A'), m);
expr_ref unit_a(seq.str.mk_unit(ch_a), m);
expr_ref ba(seq.str.mk_concat(unit_b, unit_a), m);
expr_ref to_re_ba(seq.re.mk_to_re(ba), m);
euf::snode* regex = sg.mk(to_re_ba);
// x·"A" ∈ to_re("BA") → RTL consume trailing 'A' → x ∈ to_re("B")
seq::nielsen_node* node = ng.mk_node();
seq::dep_tracker dep; dep.insert(0);
node->add_str_mem(seq::str_mem(xa, regex, e, 0, dep));
auto sr = node->simplify_and_init(ng);
SASSERT(sr == seq::simplify_result::proceed);
SASSERT(node->str_mems().size() == 1);
SASSERT(node->str_mems()[0].m_str->is_var());
SASSERT(node->str_mems()[0].m_str->id() == x->id());
euf::snode* deriv_b = sg.brzozowski_deriv(node->str_mems()[0].m_regex, sg.mk_char('B'));
SASSERT(deriv_b && deriv_b->is_nullable());
}
// test simplify_and_init: multiple eqs with mixed status
static void test_simplify_multiple_eqs() {
std::cout << "test_simplify_multiple_eqs\n";
@ -3541,6 +3658,7 @@ void tst_seq_nielsen() {
test_const_nielsen_solve_sat();
test_const_nielsen_solve_unsat();
test_const_nielsen_priority_over_eq_split();
test_const_nielsen_tail_char_var();
test_const_nielsen_not_applicable_both_vars();
test_const_nielsen_multi_char_solve();
test_var_nielsen_basic();
@ -3574,6 +3692,7 @@ void tst_seq_nielsen() {
test_solve_children_failed_reason();
test_solve_eval_idx_tracking();
test_simplify_prefix_cancel();
test_simplify_suffix_cancel_rtl();
test_simplify_symbol_clash();
test_simplify_empty_propagation();
test_simplify_empty_vs_char();
@ -3583,6 +3702,7 @@ void tst_seq_nielsen() {
test_simplify_regex_infeasible();
test_simplify_nullable_removal();
test_simplify_brzozowski_sat();
test_simplify_brzozowski_rtl_suffix();
test_simplify_multiple_eqs();
test_det_cancel_child_eq();
test_const_nielsen_child_substitutions();