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/* Copyright (C) 2020 Nikolaj J. Ulrik <nikolaj@njulrik.dk>,
* Simon M. Virenfeldt <simon@simwir.dk>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "LTL/LTL.h"
#include "LTL/LTLMain.h"
#include "PetriEngine/PQL/PQL.h"
#include "PetriEngine/PQL/Expressions.h"
#include "LTL/Algorithm/ResumingStubbornTarjan.h"
#include "LTL/SuccessorGeneration/Spoolers.h"
#include "LTL/SuccessorGeneration/Heuristics.h"
#include <utility>
using namespace PetriEngine::PQL;
#define DEBUG_EXPLORED_STATES
namespace LTL {
struct Result {
bool satisfied = false;
bool is_weak = true;
Algorithm algorithm = Algorithm::Tarjan;
#ifdef DEBUG_EXPLORED_STATES
size_t explored_states = 0;
#endif
};
/**
* Converts a formula on the form A f, E f or f into just f, assuming f is an LTL formula.
* In the case E f, not f is returned, and in this case the model checking result should be negated
* (indicated by bool in return value)
* @param formula - a formula on the form A f, E f or f
* @return @code(ltl_formula, should_negate) - ltl_formula is the formula f if it is a valid LTL formula, nullptr otherwise.
* should_negate indicates whether the returned formula is negated (in the case the parameter was E f)
*/
std::pair<Condition_ptr, bool> to_ltl(const Condition_ptr &formula)
{
LTL::LTLValidator validator;
bool should_negate = false;
Condition_ptr converted;
if (auto _formula = dynamic_cast<ECondition *>(formula.get())) {
converted = std::make_shared<NotCondition>((*_formula)[0]);
should_negate = true;
} else if (auto _formula = dynamic_cast<ACondition *>(formula.get())) {
converted = (*_formula)[0];
} else {
converted = formula;
}
converted->visit(validator);
if (validator.bad()) {
converted = nullptr;
}
return std::make_pair(converted, should_negate);
}
template<typename Checker>
Result _verify(const PetriNet *net,
Condition_ptr &negatedQuery,
std::unique_ptr<Checker> checker,
const options_t &options)
{
Result result;
/*
std::unique_ptr<Checker> modelChecker;
if constexpr (std::is_same_v<Checker, TarjanModelChecker<SpoolingSuccessorGenerator, true>> ||
std::is_same_v<Checker, TarjanModelChecker<SpoolingSuccessorGenerator, false>>) {
} else {
modelChecker = std::make_unique<Checker>(*net, negatedQuery, options.trace, options.ltluseweak);
}
*/
result.satisfied = checker->isSatisfied();
result.is_weak = checker->isweak();
#ifdef DEBUG_EXPLORED_STATES
result.explored_states = checker->get_explored();
#endif
if (options.printstatistics) {
checker->printStats(std::cout);
}
return result;
}
ReturnValue LTLMain(const PetriNet *net,
const Condition_ptr &query,
const std::string &queryName,
const options_t &options)
{
auto res = to_ltl(query);
Condition_ptr negated_formula = res.first;
bool negate_answer = res.second;
if (options.stubbornreduction && options.ltlalgorithm != Algorithm::Tarjan) {
std::cerr << "Error: Stubborn reductions only supported for Tarjan's algorithm" << std::endl;
return ErrorCode;
}
Structures::BuchiAutomaton automaton = makeBuchiAutomaton(negated_formula);
bool hasinhib = net->has_inhibitor();
Result result;
switch (options.ltlalgorithm) {
case Algorithm::NDFS:
if (options.trace != TraceLevel::None) {
result = _verify(net, negated_formula,
std::make_unique<NestedDepthFirstSearch<PetriEngine::Structures::TracableStateSet>>(
*net, negated_formula, automaton, options.trace, options.ltluseweak), options);
} else {
result = _verify(net, negated_formula,
std::make_unique<NestedDepthFirstSearch<PetriEngine::Structures::StateSet>>(
*net, negated_formula, automaton, options.trace, options.ltluseweak), options);
}
break;
case Algorithm::RandomNDFS: {
SpoolingSuccessorGenerator gen{*net, negated_formula};
gen.setSpooler(std::make_unique<EnabledSpooler>(net, gen));
gen.setHeuristic(std::make_unique<RandomHeuristic>());
result = _verify(net, negated_formula,
std::make_unique<RandomNDFS>(*net, negated_formula, automaton, std::move(gen), options.trace,
options.ltluseweak),
options);
break;
}
case Algorithm::Tarjan:
if (options.strategy != PetriEngine::Reachability::DEFAULT ||
(!hasinhib && options.stubbornreduction && !negated_formula->containsNext())) {
// Use spooling successor generator in case of different search strategy or stubborn set method.
SpoolingSuccessorGenerator gen{*net, negated_formula};
if (!hasinhib && options.stubbornreduction && !negated_formula->containsNext()) {
std::cout << "Running stubborn version!" << std::endl;
gen.setSpooler(std::make_unique<InterestingLTLStubbornSet>(*net, negated_formula));
}
else {
gen.setSpooler(std::make_unique<EnabledSpooler>(net, gen));
}
if (options.strategy == PetriEngine::Reachability::RDFS) {
gen.setHeuristic(std::make_unique<RandomHeuristic>());
} else if (options.strategy == PetriEngine::Reachability::HEUR) {
//gen.setHeuristic(std::make_unique<AutomatonHeuristic>(net, automaton));
gen.setHeuristic(std::make_unique<FireCountHeuristic>(net));
}
if (options.trace != TraceLevel::None) {
result = _verify(net, negated_formula,
std::make_unique<TarjanModelChecker<SpoolingSuccessorGenerator, true>>(
*net,
negated_formula,
automaton,
std::move(gen),
options.trace,
options.ltluseweak),
options);
} else {
result = _verify(net, negated_formula,
std::make_unique<TarjanModelChecker<SpoolingSuccessorGenerator, false>>(
*net,
negated_formula,
automaton,
std::move(gen),
options.trace,
options.ltluseweak),
options);
}
} else {
// no spooling needed, thus use resuming successor generation
if (options.trace != TraceLevel::None) {
result = _verify(net, negated_formula,
std::make_unique<TarjanModelChecker<ResumingSuccessorGenerator, true>>(
*net,
negated_formula,
automaton,
ResumingSuccessorGenerator{*net},
options.trace,
options.ltluseweak),
options);
} else {
result = _verify(net, negated_formula,
std::make_unique<TarjanModelChecker<ResumingSuccessorGenerator, false>>(
*net,
negated_formula,
automaton,
ResumingSuccessorGenerator{*net},
options.trace,
options.ltluseweak),
options);
}
}
break;
case Algorithm::None:
assert(false);
std::cerr << "Error: cannot LTL verify with algorithm None";
}
std::cout << "FORMULA " << queryName
<< (result.satisfied ^ negate_answer ? " TRUE" : " FALSE") << " TECHNIQUES EXPLICIT "
<< LTL::to_string(options.ltlalgorithm)
<< (result.is_weak ? " WEAK_SKIP" : "")
<< ((options.stubbornreduction && !negated_formula->containsNext()) ? " STUBBORN" : "")
<< std::endl;
#ifdef DEBUG_EXPLORED_STATES
std::cout << "FORMULA " << queryName << " STATS EXPLORED " << result.explored_states << std::endl;
#endif
/*(queries[qid]->isReachability(0) ? " REACHABILITY" : "") <<*/
return SuccessCode;
}
}
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