mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2026-05-23 10:29:38 +00:00
Code Activity

update proof formats for new core

Browse source 
- update proof format for quantifier instantiation to track original literals
- update proof replay tools with ability to extract proof object

The formats and features are subject to heavy revisions.

Example
```
(set-option :sat.euf true)
(set-option :sat.smt.proof eufproof.smt2)
(declare-fun f (Int) Int)
(declare-const x Int)
(assert (or (= (f (f (f x))) x) (= (f (f x)) x)))
(assert (not (= (f (f (f (f (f (f x)))))) x)))
(check-sat)
```

eufproof.smt2 is:
```
(declare-fun x () Int)
(declare-fun f (Int) Int)
(define-const $24 Int (f x))
(define-const $25 Int (f $24))
(define-const $26 Int (f $25))
(define-const $27 Bool (= $26 x))
(define-const $28 Bool (= $25 x))
(assume $27 $28)
(define-const $30 Int (f $26))
(define-const $31 Int (f $30))
(define-const $32 Int (f $31))
(define-const $33 Bool (= $32 x))
(assume (not $33))
(declare-fun rup () Proof)
(infer (not $33) rup)
(declare-fun euf (Bool Bool Proof Proof Proof Proof) Proof)
(declare-fun cc (Bool) Proof)
(define-const $42 Bool (= $32 $30))
(define-const $43 Proof (cc $42))
(define-const $40 Bool (= $31 $24))
(define-const $41 Proof (cc $40))
(define-const $38 Bool (= $30 $25))
(define-const $39 Proof (cc $38))
(define-const $36 Bool (= $24 $26))
(define-const $37 Proof (cc $36))
(define-const $34 Bool (not $33))
(define-const $44 Proof (euf $34 $28 $37 $39 $41 $43))
(infer (not $28) $33 $44)
(infer (not $28) rup)
(infer $27 rup)
(declare-fun euf (Bool Bool Proof Proof Proof) Proof)
(define-const $49 Bool (= $32 $26))
(define-const $50 Proof (cc $49))
(define-const $47 Bool (= $31 $25))
(define-const $48 Proof (cc $47))
(define-const $45 Bool (= $24 $30))
(define-const $46 Proof (cc $45))
(define-const $51 Proof (euf $34 $27 $46 $48 $50))
(infer $33 $51)
(infer rup)
```

Example of inspecting proof from Python:

```
from z3 import *

def parse(file):
    s = Solver()
    set_option("solver.proof.save", True)
    set_option("solver.proof.check", False)
    s.from_file(file)
    for step in s.proof().children():
        print(step)

parse("../eufproof.smt2")
```

Proof checking (self-validation) is on by default.
Proof saving is off by default.

You can use the proof logs and the proof terms to retrieve quantifier instantiations from the new core.

The self-checker contains a few built-in tuned checkers but falls back to self-checking inferred clauses using SMT.
This commit is contained in:
Nikolaj Bjorner 2022-09-28 10:40:43 -07:00
parent 9782d4a730
commit 107981f099
40 changed files with 295 additions and 153 deletions
Download patch file Download diff file Expand all files Collapse all files

26
src/sat/smt/euf_proof.cpp
View file

@ -92,16 +92,20 @@ namespace euf {
expr* eq_proof_hint::get_hint(euf::solver& s) const {
ast_manager& m = s.get_manager();
func_decl_ref cc(m);
func_decl_ref cc(m), cc_comm(m);
sort* proof = m.mk_proof_sort();
ptr_buffer<sort> sorts;
expr_ref_vector args(m);
if (m_cc_head < m_cc_tail) {
sort* sorts[2] = { m.mk_bool_sort(), m.mk_bool_sort() };
cc = m.mk_func_decl(symbol("cc"), 2, sorts, proof);
sort* sorts[1] = { m.mk_bool_sort() };
cc_comm = m.mk_func_decl(symbol("comm"), 1, sorts, proof);
cc = m.mk_func_decl(symbol("cc"), 1, sorts, proof);
}
auto cc_proof = [&](bool comm, expr* eq) {
return m.mk_app(cc, m.mk_bool_val(comm), eq);
if (comm)
return m.mk_app(cc_comm, eq);
else
return m.mk_app(cc, eq);
};
auto compare_ts = [](cc_justification_record const& a,
cc_justification_record const& b) {
@ -168,11 +172,11 @@ namespace euf {
if (!visit_clause(out, n, lits))
return;
if (st.is_asserted())
display_redundant(out, n, lits, status2proof_hint(st));
display_inferred(out, n, lits, status2proof_hint(st));
else if (st.is_deleted())
display_deleted(out, n, lits);
else if (st.is_redundant())
display_redundant(out, n, lits, status2proof_hint(st));
display_inferred(out, n, lits, status2proof_hint(st));
else if (st.is_input())
display_assume(out, n, lits);
else
@ -228,10 +232,12 @@ namespace euf {
display_literals(out << "(assume", n, lits) << ")\n";
}
void solver::display_redundant(std::ostream& out, unsigned n, literal const* lits, expr* proof_hint) {
if (proof_hint)
visit_expr(out, proof_hint);
display_hint(display_literals(out << "(learn", n, lits), proof_hint) << ")\n";
void solver::display_inferred(std::ostream& out, unsigned n, literal const* lits, expr* proof_hint) {
expr_ref hint(proof_hint, m);
if (!hint)
hint = m.mk_const(symbol("smt"), m.mk_proof_sort());
visit_expr(out, hint);
display_hint(display_literals(out << "(infer", n, lits), hint) << ")\n";
}
void solver::display_deleted(std::ostream& out, unsigned n, literal const* lits) {