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add hint verification, combine bounds/farkas into one rule

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2022-05-29 10:12:05 -07:00
parent 36ad377a7d
commit bffa7ff2f6
9 changed files with 59 additions and 49 deletions
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37
scripts/nightly.yaml
View file

@ -104,25 +104,26 @@ stages:
artifactName: '$(name)Build'
targetPath: $(Build.ArtifactStagingDirectory)
# - job: MuslLinuxBuild
# variables:
# python: "/opt/python/cp310-cp310/bin/python"
# name: MuslLinux
# displayName: "MuslLinux build"
# pool:
# vmImage: "Ubuntu-18.04"
# container: "quay.io/pypa/musllinux_1_1_x86_64:latest"
# steps:
# - script: $(python) scripts/mk_unix_dist.py --nodotnet --nojava
# - script: git clone https://github.com/z3prover/z3test z3test
# - script: $(python) z3test/scripts/test_benchmarks.py build-dist/z3 z3test/regressions/smt2
# - script: cp dist/*.zip $(Build.ArtifactStagingDirectory)/
# - task: PublishPipelineArtifact@0
# inputs:
# artifactName: '$(name)Build'
# targetPath: $(Build.ArtifactStagingDirectory)
- job: MuslLinuxBuild
condition: eq(0,1)
variables:
python: "/opt/python/cp310-cp310/bin/python"
name: MuslLinux
displayName: "MuslLinux build"
pool:
vmImage: "Ubuntu-18.04"
container: "quay.io/pypa/musllinux_1_1_x86_64:latest"
steps:
- script: $(python) scripts/mk_unix_dist.py --nodotnet --nojava
- script: git clone https://github.com/z3prover/z3test z3test
- script: $(python) z3test/scripts/test_benchmarks.py build-dist/z3 z3test/regressions/smt2
- script: cp dist/*.zip $(Build.ArtifactStagingDirectory)/
- task: PublishPipelineArtifact@0
inputs:
artifactName: '$(name)Build'
targetPath: $(Build.ArtifactStagingDirectory)
- job: Windows32
- job: Windows32
displayName: "Windows 32-bit build"
pool:
vmImage: "windows-latest"

2
src/sat/dimacs.cpp
View file

@ -115,7 +115,6 @@ static void read_clause(Buffer & in, std::ostream& err, sat::literal_vector & li
template<typename Buffer>
static void read_pragma(Buffer & in, std::ostream& err, std::string& p, sat::proof_hint& h) {
skip_whitespace(in);
h.reset();
if (*in != 'p')
return;
++in;
@ -307,6 +306,7 @@ namespace dimacs {
loop:
skip_whitespace(in);
m_record.m_pragma.clear();
m_record.m_hint.reset();
switch (*in) {
case EOF:
return false;

8
src/sat/sat_drat.cpp
View file

@ -918,9 +918,6 @@ namespace sat {
case hint_type::farkas_h:
ous << "farkas ";
break;
case hint_type::bound_h:
ous << "bound ";
break;
case hint_type::cut_h:
ous << "cut ";
break;
@ -949,11 +946,6 @@ namespace sat {
s += 6;
return true;
}
if (0 == strncmp(s, "bound", 5)) {
h.m_ty = hint_type::bound_h;
s += 5;
return true;
}
return false;
};

1
src/sat/sat_types.h
View file

@ -97,7 +97,6 @@ namespace sat {
enum class hint_type {
null_h,
farkas_h,
bound_h,
cut_h
};

9
src/sat/smt/arith_diagnostics.cpp
View file

@ -81,13 +81,14 @@ namespace arith {
}
/**
* Assumption:
* It may be necessary to use the following assumption when checking Farkas claims
* generated from bounds propagation:
* A bound literal ax <= b is explained by a set of weighted literals
* r1*(a1*x <= b1) + .... + r_k*(a_k*x <= b_k), where r_i > 0
* such that there is a r >= 1
* (r1*a1+..+r_k*a_k) = r*a, (r1*b1+..+r_k*b_k) <= r*b
*/
sat::proof_hint const* solver::explain(sat::hint_type ty) {
sat::proof_hint const* solver::explain(sat::hint_type ty, sat::literal lit) {
if (!ctx.use_drat())
return nullptr;
m_bounds_pragma.m_ty = ty;
@ -105,6 +106,8 @@ namespace arith {
}
case equality_source: {
auto [u, v] = m_equalities[idx];
ctx.drat_log_expr(u->get_expr());
ctx.drat_log_expr(v->get_expr());
m_bounds_pragma.m_eqs.push_back({ev.coeff(), u->get_expr_id(), v->get_expr_id()});
break;
}
@ -112,6 +115,8 @@ namespace arith {
break;
}
}
if (lit != sat::null_literal)
m_bounds_pragma.m_literals.push_back({rational(1), ~lit});
return &m_bounds_pragma;
}
}

6
src/sat/smt/arith_solver.cpp
View file

@ -263,7 +263,7 @@ namespace arith {
TRACE("arith", for (auto lit : m_core) tout << lit << ": " << s().value(lit) << "\n";);
DEBUG_CODE(for (auto lit : m_core) { VERIFY(s().value(lit) == l_true); });
++m_stats.m_bound_propagations1;
assign(lit, m_core, m_eqs, explain(sat::hint_type::bound_h));
assign(lit, m_core, m_eqs, explain(sat::hint_type::farkas_h, lit));
}
if (should_refine_bounds() && first)
@ -378,7 +378,7 @@ namespace arith {
reset_evidence();
m_explanation.clear();
lp().explain_implied_bound(be, m_bp);
assign(bound, m_core, m_eqs, explain(sat::hint_type::bound_h));
assign(bound, m_core, m_eqs, explain(sat::hint_type::farkas_h, bound));
}
@ -1177,7 +1177,7 @@ namespace arith {
app_ref b = mk_bound(m_lia->get_term(), m_lia->get_offset(), !m_lia->is_upper());
IF_VERBOSE(4, verbose_stream() << "cut " << b << "\n");
literal lit = expr2literal(b);
assign(lit, m_core, m_eqs, explain(sat::hint_type::cut_h));
assign(lit, m_core, m_eqs, explain(sat::hint_type::cut_h, lit));
lia_check = l_false;
break;
}

2
src/sat/smt/arith_solver.h
View file

@ -421,7 +421,7 @@ namespace arith {
sat::proof_hint m_bounds_pragma;
sat::proof_hint m_farkas2;
sat::proof_hint const* explain(sat::hint_type ty);
sat::proof_hint const* explain(sat::hint_type ty, sat::literal lit = sat::null_literal);
public:

2
src/sat/smt/euf_solver.h
View file

@ -176,7 +176,6 @@ namespace euf {
void log_antecedents(literal l, literal_vector const& r);
void log_justification(literal l, th_explain const& jst);
void drat_log_decl(func_decl* f);
void drat_log_expr(expr* n);
void drat_log_expr1(expr* n);
ptr_vector<expr> m_drat_todo;
obj_hashtable<ast> m_drat_asts;
@ -345,6 +344,7 @@ namespace euf {
sat::drat& get_drat() { return s().get_drat(); }
void drat_bool_def(sat::bool_var v, expr* n);
void drat_eq_def(sat::literal lit, expr* eq);
void drat_log_expr(expr* n);
// decompile
bool extract_pb(std::function<void(unsigned sz, literal const* c, unsigned k)>& card,

41
src/shell/drat_frontend.cpp
View file

@ -160,16 +160,15 @@ public:
// m_drat.add(lits, st);
}
void validate_hint(sat::literal_vector const& lits, sat::proof_hint const& hint) {
return; // remove when testing this
void validate_hint(expr_ref_vector const& exprs, sat::literal_vector const& lits, sat::proof_hint const& hint) {
// return; // remove when testing this
proof_checker pc(m);
arith_util autil(m);
switch (hint.m_ty) {
case sat::hint_type::null_h:
break;
case sat::hint_type::bound_h: {
// TODO: combine bound_h and farkas_h into a single rule
// TODO: use proof_checker.cpp check_arith_proof to check farkas claim
case sat::hint_type::cut_h:
case sat::hint_type::farkas_h: {
expr_ref sum(m);
bool is_strict = false;
vector<rational> coeffs;
@ -178,6 +177,10 @@ public:
coeffs.push_back(coeff);
lc = lcm(lc, denominator(coeff));
}
for (auto const& [coeff, a, b]: hint.m_eqs) {
coeffs.push_back(coeff);
lc = lcm(lc, denominator(coeff));
}
if (!lc.is_one())
for (auto& coeff : coeffs)
coeff *= lc;
@ -186,13 +189,25 @@ public:
for (auto const& [coeff, lit] : hint.m_literals) {
app_ref e(to_app(m_b2e[lit.var()]), m);
if (!pc.check_arith_literal(!lit.sign(), e, coeffs[i], sum, is_strict)) {
std::cout << "Failed checking hint " << e << "\n";
std::cout << "p failed checking hint " << e << "\n";
return;
}
++i;
}
for (auto const& [coeff, a, b]: hint.m_eqs) {
expr* x = exprs[a];
expr* y = exprs[b];
coeffs.push_back(coeff);
app_ref e(m.mk_eq(x, y), m);
if (!pc.check_arith_literal(true, e, coeffs[i], sum, is_strict)) {
std::cout << "p failed checking hint " << e << "\n";
return;
}
++i;
}
if (!sum.get()) {
std::cout << "no summation\n";
std::cout << "p no summation\n";
return;
}
@ -204,16 +219,14 @@ public:
th_rewriter rw(m);
rw(sum);
if (!m.is_false(sum)) {
std::cout << "Lemma not simplified " << sum << "\n";
std::cout << "p hint not verified " << sum << "\n";
return;
}
std::cout << "p hint verified\n";
break;
}
case sat::hint_type::farkas_h:
std::cout << "FARKAS\n";
break;
case sat::hint_type::cut_h:
std::cout << "CUT\n";
default:
UNREACHABLE();
break;
}
}
@ -405,7 +418,7 @@ static void verify_smt(char const* drat_file, char const* smt_file) {
switch (r.m_tag) {
case dimacs::drat_record::tag_t::is_clause:
checker.add(r.m_lits, r.m_status);
checker.validate_hint(r.m_lits, r.m_hint);
checker.validate_hint(exprs, r.m_lits, r.m_hint);
if (drat_checker.inconsistent()) {
std::cout << "inconsistent\n";
return;