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#include "storm-pomdp/analysis/MemlessStrategySearchQualitative.h"
#include "storm/utility/file.h"
namespace storm {
namespace pomdp {
namespace detail {
void printRelevantInfoFromModel(std::shared_ptr<storm::solver::SmtSolver::ModelReference> const& model, std::vector<storm::expressions::Variable> const& reachVars, std::vector<storm::expressions::Variable> const& continuationVars) {
uint64_t i = 0;
std::stringstream ss;
STORM_LOG_TRACE("states which we have now: ");
for (auto rv : reachVars) {
if (model->getBooleanValue(rv)) {
ss << " " << i;
}
++i;
}
STORM_LOG_TRACE(ss.str());
i = 0;
STORM_LOG_TRACE("states from which we continue: ");
ss.clear();
for (auto rv : continuationVars) {
if (model->getBooleanValue(rv)) {
ss << " " << i;
}
++i;
}
STORM_LOG_TRACE(ss.str());
}
}
template <typename ValueType>
MemlessStrategySearchQualitative<ValueType>::MemlessStrategySearchQualitative(storm::models::sparse::Pomdp<ValueType> const& pomdp,
std::set<uint32_t> const& targetObservationSet,
storm::storage::BitVector const& targetStates,
storm::storage::BitVector const& surelyReachSinkStates,
std::shared_ptr<storm::utility::solver::SmtSolverFactory>& smtSolverFactory,
MemlessSearchOptions const& options) :
pomdp(pomdp),
targetStates(targetStates),
surelyReachSinkStates(surelyReachSinkStates),
targetObservations(targetObservationSet),
options(options)
{
this->expressionManager = std::make_shared<storm::expressions::ExpressionManager>();
smtSolver = smtSolverFactory->create(*expressionManager);
// Initialize states per observation.
for (uint64_t obs = 0; obs < pomdp.getNrObservations(); ++obs) {
statesPerObservation.push_back(std::vector<uint64_t>()); // Consider using bitvectors instead.
}
uint64_t state = 0;
for (auto obs : pomdp.getObservations()) {
statesPerObservation.at(obs).push_back(state++);
}
// Initialize winning region
std::vector<uint64_t> nrStatesPerObservation;
for (auto const &states : statesPerObservation) {
nrStatesPerObservation.push_back(states.size());
}
winningRegion = WinningRegion(nrStatesPerObservation);
}
template <typename ValueType>
void MemlessStrategySearchQualitative<ValueType>::initialize(uint64_t k) {
if (maxK == std::numeric_limits<uint64_t>::max()) {
// not initialized at all.
// Create some data structures.
for(uint64_t obs = 0; obs < pomdp.getNrObservations(); ++obs) {
actionSelectionVars.push_back(std::vector<storm::expressions::Variable>());
actionSelectionVarExpressions.push_back(std::vector<storm::expressions::Expression>());
}
// Fill the states-per-observation mapping,
// declare the reachability variables,
// declare the path variables.
for(uint64_t stateId = 0; stateId < pomdp.getNumberOfStates(); ++stateId) {
pathVars.push_back(std::vector<storm::expressions::Expression>());
for (uint64_t i = 0; i < k; ++i) {
pathVars.back().push_back(expressionManager->declareBooleanVariable("P-"+std::to_string(stateId)+"-"+std::to_string(i)).getExpression());
}
reachVars.push_back(expressionManager->declareBooleanVariable("C-" + std::to_string(stateId)));
reachVarExpressions.push_back(reachVars.back().getExpression());
continuationVars.push_back(expressionManager->declareBooleanVariable("D-" + std::to_string(stateId)));
continuationVarExpressions.push_back(continuationVars.back().getExpression());
}
assert(pathVars.size() == pomdp.getNumberOfStates());
assert(reachVars.size() == pomdp.getNumberOfStates());
assert(reachVarExpressions.size() == pomdp.getNumberOfStates());
// Create the action selection variables.
uint64_t obs = 0;
for(auto const& statesForObservation : statesPerObservation) {
for (uint64_t a = 0; a < pomdp.getNumberOfChoices(statesForObservation.front()); ++a) {
std::string varName = "A-" + std::to_string(obs) + "-" + std::to_string(a);
actionSelectionVars.at(obs).push_back(expressionManager->declareBooleanVariable(varName));
actionSelectionVarExpressions.at(obs).push_back(actionSelectionVars.at(obs).back().getExpression());
}
schedulerVariables.push_back(expressionManager->declareBitVectorVariable("scheduler-obs-" + std::to_string(obs), statesPerObservation.size()));
schedulerVariableExpressions.push_back(schedulerVariables.back());
switchVars.push_back(expressionManager->declareBooleanVariable("S-" + std::to_string(obs)));
switchVarExpressions.push_back(switchVars.back().getExpression());
++obs;
}
for (auto const& actionVars : actionSelectionVarExpressions) {
smtSolver->add(storm::expressions::disjunction(actionVars));
}
for (uint64_t state = 0; state < pomdp.getNumberOfStates(); ++state) {
if (targetStates.get(state)) {
smtSolver->add(pathVars[state][0]);
} else {
smtSolver->add(!pathVars[state][0]);
}
}
uint64_t rowindex = 0;
for (uint64_t state = 0; state < pomdp.getNumberOfStates(); ++state) {
for (uint64_t action = 0; action < pomdp.getNumberOfChoices(state); ++action) {
std::vector<storm::expressions::Expression> subexprreachSwitch;
std::vector<storm::expressions::Expression> subexprreachNoSwitch;
subexprreachSwitch.push_back(!reachVarExpressions[state]);
subexprreachSwitch.push_back(!actionSelectionVarExpressions[pomdp.getObservation(state)][action]);
subexprreachSwitch.push_back(!switchVarExpressions[pomdp.getObservation(state)]);
subexprreachNoSwitch.push_back(!reachVarExpressions[state]);
subexprreachNoSwitch.push_back(!actionSelectionVarExpressions[pomdp.getObservation(state)][action]);
subexprreachNoSwitch.push_back(switchVarExpressions[pomdp.getObservation(state)]);
for (auto const &entries : pomdp.getTransitionMatrix().getRow(rowindex)) {
subexprreachSwitch.push_back(continuationVarExpressions.at(entries.getColumn()));
smtSolver->add(storm::expressions::disjunction(subexprreachSwitch));
subexprreachSwitch.pop_back();
subexprreachNoSwitch.push_back(reachVarExpressions.at(entries.getColumn()));
smtSolver->add(storm::expressions::disjunction(subexprreachNoSwitch));
subexprreachNoSwitch.pop_back();
}
rowindex++;
}
}
smtSolver->push();
} else {
smtSolver->pop();
smtSolver->pop();
smtSolver->push();
assert(false);
}
uint64_t rowindex = 0;
for (uint64_t state = 0; state < pomdp.getNumberOfStates(); ++state) {
if (surelyReachSinkStates.get(state)) {
smtSolver->add(!reachVarExpressions[state]);
for (uint64_t j = 1; j < k; ++j) {
smtSolver->add(!pathVars[state][j]);
}
smtSolver->add(!continuationVarExpressions[state]);
} else if(!targetStates.get(state)) {
std::vector<std::vector<std::vector<storm::expressions::Expression>>> pathsubsubexprs;
for (uint64_t j = 1; j < k; ++j) {
pathsubsubexprs.push_back(std::vector<std::vector<storm::expressions::Expression>>());
for (uint64_t action = 0; action < pomdp.getNumberOfChoices(state); ++action) {
pathsubsubexprs.back().push_back(std::vector<storm::expressions::Expression>());
}
}
for (uint64_t action = 0; action < pomdp.getNumberOfChoices(state); ++action) {
std::vector<storm::expressions::Expression> subexprreach;
for (auto const &entries : pomdp.getTransitionMatrix().getRow(rowindex)) {
for (uint64_t j = 1; j < k; ++j) {
pathsubsubexprs[j - 1][action].push_back(pathVars[entries.getColumn()][j - 1]);
}
}
rowindex++;
}
smtSolver->add(storm::expressions::implies(reachVarExpressions.at(state), pathVars.at(state).back()));
for (uint64_t j = 1; j < k; ++j) {
std::vector<storm::expressions::Expression> pathsubexprs;
for (uint64_t action = 0; action < pomdp.getNumberOfChoices(state); ++action) {
pathsubexprs.push_back(actionSelectionVarExpressions.at(pomdp.getObservation(state)).at(action) && storm::expressions::disjunction(pathsubsubexprs[j - 1][action]));
}
pathsubexprs.push_back(switchVarExpressions.at(pomdp.getObservation(state)));
smtSolver->add(storm::expressions::iff(pathVars[state][j], storm::expressions::disjunction(pathsubexprs)));
}
}
}
uint64_t obs = 0;
for(auto const& statesForObservation : statesPerObservation) {
for(auto const& state : statesForObservation) {
smtSolver->add(!continuationVars[state] || schedulerVariableExpressions[obs] > 0);
}
++obs;
}
// TODO: Update found schedulers if k is increased.
}
template <typename ValueType>
bool MemlessStrategySearchQualitative<ValueType>::analyze(uint64_t k, storm::storage::BitVector const& oneOfTheseStates, storm::storage::BitVector const& allOfTheseStates) {
if (k < maxK) {
initialize(k);
maxK = k;
}
std::vector<storm::expressions::Expression> atLeastOneOfStates;
for (uint64_t state : oneOfTheseStates) {
STORM_LOG_ASSERT(reachVarExpressions.size() > state, "state id " << state << " exceeds number of states (" << reachVarExpressions.size() << ")" );
atLeastOneOfStates.push_back(reachVarExpressions[state]);
}
assert(atLeastOneOfStates.size() > 0);
smtSolver->add(storm::expressions::disjunction(atLeastOneOfStates));
for (uint64_t state : allOfTheseStates) {
assert(reachVarExpressions.size() > state);
smtSolver->add(reachVarExpressions[state]);
}
smtSolver->push();
uint64_t obs = 0;
for(auto const& statesForObservation : statesPerObservation) {
smtSolver->add(schedulerVariableExpressions[obs] <= schedulerForObs.size());
++obs;
}
for (uint64_t ob = 0; ob < pomdp.getNrObservations(); ++ob) {
schedulerForObs.push_back(std::vector<uint64_t>());
}
InternalObservationScheduler scheduler;
scheduler.switchObservations = storm::storage::BitVector(pomdp.getNrObservations());
storm::storage::BitVector observations(pomdp.getNrObservations());
storm::storage::BitVector observationsAfterSwitch(pomdp.getNrObservations());
storm::storage::BitVector remainingstates(pomdp.getNumberOfStates());
uint64_t iterations = 0;
while(true) {
scheduler.clear();
observations.clear();
observationsAfterSwitch.clear();
remainingstates.clear();
while (true) {
++iterations;
if(options.isExportSATSet()) {
STORM_LOG_DEBUG("Export SMT Solver Call (" <<iterations << ")");
std::string filepath = options.getExportSATCallsPath() + "call_" + std::to_string(iterations) + ".smt2";
std::ofstream filestream;
storm::utility::openFile(filepath, filestream);
filestream << smtSolver->getSmtLibString() << std::endl;
storm::utility::closeFile(filestream);
}
STORM_LOG_DEBUG("Call to SMT Solver (" <<iterations << ")");
auto result = smtSolver->check();
uint64_t i = 0;
if (result == storm::solver::SmtSolver::CheckResult::Unknown) {
STORM_LOG_THROW(false, storm::exceptions::UnexpectedException, "SMT solver yielded an unexpected result");
} else if (result == storm::solver::SmtSolver::CheckResult::Unsat) {
STORM_LOG_DEBUG("Unsatisfiable!");
break;
}
STORM_LOG_DEBUG("Satisfying assignment: ");
STORM_LOG_TRACE(smtSolver->getModelAsValuation().toString(true));
auto model = smtSolver->getModel();
observations.clear();
observationsAfterSwitch.clear();
remainingstates.clear();
scheduler.clear();
for (auto rv : reachVars) {
if (model->getBooleanValue(rv)) {
smtSolver->add(rv.getExpression());
observations.set(pomdp.getObservation(i));
} else {
remainingstates.set(i);
}
++i;
}
i = 0;
for (auto rv : continuationVars) {
if (model->getBooleanValue(rv)) {
smtSolver->add(rv.getExpression());
observationsAfterSwitch.set(pomdp.getObservation(i));
}
++i;
}
if (options.computeTraceOutput()) {
detail::printRelevantInfoFromModel(model, reachVars, continuationVars);
}
// TODO do not repush everyting to the solver.
std::vector<storm::expressions::Expression> schedulerSoFar;
uint64_t obs = 0;
for (auto const &actionSelectionVarsForObs : actionSelectionVars) {
scheduler.actions.push_back(std::set<uint64_t>());
if (observations.get(obs)) {
for (uint64_t act = 0; act < actionSelectionVarsForObs.size(); ++act) {
auto const& asv = actionSelectionVarsForObs[act];
if (model->getBooleanValue(asv)) {
scheduler.actions.back().insert(act);
schedulerSoFar.push_back(actionSelectionVarExpressions[obs][act]);
}
}
if (model->getBooleanValue(switchVars[obs])) {
scheduler.switchObservations.set(obs);
schedulerSoFar.push_back(switchVarExpressions[obs]);
} else {
schedulerSoFar.push_back(!switchVarExpressions[obs]);
}
}
if (observationsAfterSwitch.get(obs)) {
scheduler.schedulerRef.push_back(model->getIntegerValue(schedulerVariables[obs]));
schedulerSoFar.push_back(schedulerVariableExpressions[obs] == expressionManager->integer(scheduler.schedulerRef.back()));
} else {
scheduler.schedulerRef.push_back(0);
}
obs++;
}
if(options.computeTraceOutput()) {
// generates debug output, but here we only want it for trace level.
// For consistency, all output on debug level.
STORM_LOG_DEBUG("the scheduler so far: ");
scheduler.printForObservations(observations,observationsAfterSwitch);
}
std::vector<storm::expressions::Expression> remainingExpressions;
for (auto index : remainingstates) {
remainingExpressions.push_back(reachVarExpressions[index]);
}
// Add scheduler
smtSolver->add(storm::expressions::conjunction(schedulerSoFar));
smtSolver->add(storm::expressions::disjunction(remainingExpressions));
}
if (scheduler.empty()) {
break;
}
smtSolver->pop();
if(options.computeDebugOutput()) {
printCoveredStates(remainingstates);
// generates info output, but here we only want it for debug level.
// For consistency, all output on info level.
STORM_LOG_DEBUG("the scheduler: ");
scheduler.printForObservations(observations,observationsAfterSwitch);
}
std::vector<storm::expressions::Expression> remainingExpressions;
for (auto index : remainingstates) {
remainingExpressions.push_back(reachVarExpressions[index]);
}
for (uint64_t observation = 0; observation < pomdp.getNrObservations(); ++observation) {
storm::storage::BitVector update = storm::storage::BitVector(statesPerObservation[observation].size());
uint64_t i = 0;
for (uint64_t state : statesPerObservation[observation]) {
if (!remainingstates.get(state)) {
update.set(i);
}
}
winningRegion.update(observation, update);
++i;
}
smtSolver->add(storm::expressions::disjunction(remainingExpressions));
uint64_t obs = 0;
for (auto const &statesForObservation : statesPerObservation) {
if (observations.get(obs)) {
STORM_LOG_DEBUG("We have a new policy ( " << finalSchedulers.size() << " ) for states with observation " << obs << ".");
assert(schedulerForObs.size() > obs);
schedulerForObs[obs].push_back(finalSchedulers.size());
STORM_LOG_DEBUG("We now have " << schedulerForObs[obs].size() << " policies for states with observation " << obs);
for (auto const &state : statesForObservation) {
if (remainingstates.get(state)) {
auto constant = expressionManager->integer(schedulerForObs[obs].size());
smtSolver->add(!(continuationVarExpressions[state] && (schedulerVariableExpressions[obs] == constant)));
}
}
}
++obs;
}
finalSchedulers.push_back(scheduler);
smtSolver->push();
for (uint64_t obs = 0; obs < pomdp.getNrObservations(); ++obs) {
auto constant = expressionManager->integer(schedulerForObs[obs].size());
smtSolver->add(schedulerVariableExpressions[obs] <= constant);
}
}
return true;
}
template<typename ValueType>
void MemlessStrategySearchQualitative<ValueType>::printCoveredStates(storm::storage::BitVector const &remaining) const {
STORM_LOG_DEBUG("states that are okay");
for (uint64_t state = 0; state < pomdp.getNumberOfStates(); ++state) {
if (!remaining.get(state)) {
std::cout << " " << state;
}
}
std::cout << std::endl;
}
template<typename ValueType>
void MemlessStrategySearchQualitative<ValueType>::printScheduler(std::vector<InternalObservationScheduler> const& ) {
}
template <typename ValueType>
storm::expressions::Expression const& MemlessStrategySearchQualitative<ValueType>::getDoneActionExpression(uint64_t obs) const {
return actionSelectionVarExpressions[obs].back();
}
template class MemlessStrategySearchQualitative<double>;
template class MemlessStrategySearchQualitative<storm::RationalNumber>;
}
}