77 lines
2.5 KiB
C++
77 lines
2.5 KiB
C++
// Copyright 2010-2025 Google LLC
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
#include "ortools/sat/lrat_proof_handler.h"
|
|
|
|
#include <memory>
|
|
#include <vector>
|
|
|
|
#include "absl/types/span.h"
|
|
#include "gtest/gtest.h"
|
|
#include "ortools/sat/model.h"
|
|
#include "ortools/sat/sat_base.h"
|
|
#include "ortools/sat/util.h"
|
|
|
|
namespace operations_research::sat {
|
|
namespace {
|
|
|
|
TEST(AddAndProveInferredClauseByEnumerationTest, XorEquivalence) {
|
|
// We assume a = XOR(c,d) and b = XOR(c,d) and we want to prove a => b
|
|
const Literal a(+1);
|
|
const Literal b(+2);
|
|
const Literal c(+3);
|
|
const Literal d(+4);
|
|
|
|
// Encode the two XOR gates.
|
|
CompactVectorVector<int, Literal> clauses;
|
|
for (const Literal x : {a, b}) {
|
|
clauses.Add({c, d, x.Negated()});
|
|
clauses.Add({c.Negated(), d, x});
|
|
clauses.Add({c, d.Negated(), x});
|
|
clauses.Add({c.Negated(), d.Negated(), x.Negated()});
|
|
}
|
|
|
|
// Create the lrat checker.
|
|
Model model;
|
|
auto* params = model.GetOrCreate<SatParameters>();
|
|
params->set_check_lrat_proof(true);
|
|
params->set_check_drat_proof(true);
|
|
std::unique_ptr<LratProofHandler> lrat =
|
|
LratProofHandler::MaybeCreate(&model);
|
|
|
|
// Lets create ids for all these clauses.
|
|
auto* id_generator = model.GetOrCreate<ClauseIdGenerator>();
|
|
std::vector<ClauseId> clause_ids;
|
|
for (int i = 0; i < clauses.size(); ++i) {
|
|
const ClauseId id = id_generator->GetNextId();
|
|
clause_ids.push_back(id);
|
|
lrat->AddProblemClause(id, clauses[i]);
|
|
}
|
|
lrat->EndProblemClauses();
|
|
|
|
// This should be enough to prove equivalence.
|
|
{
|
|
std::vector<Literal> to_prove = {b.Negated(), a};
|
|
EXPECT_NE(kNoClauseId, lrat->AddAndProveInferredClauseByEnumeration(
|
|
to_prove, clause_ids, clauses));
|
|
}
|
|
{
|
|
std::vector<Literal> to_prove = {a.Negated(), b};
|
|
EXPECT_NE(kNoClauseId, lrat->AddAndProveInferredClauseByEnumeration(
|
|
to_prove, clause_ids, clauses));
|
|
}
|
|
}
|
|
|
|
} // namespace
|
|
} // namespace operations_research::sat
|