diff --git a/src/modelchecker/abstraction/GameBasedMdpModelChecker.cpp b/src/modelchecker/abstraction/GameBasedMdpModelChecker.cpp index 71a9a4df6..d300fcdf5 100644 --- a/src/modelchecker/abstraction/GameBasedMdpModelChecker.cpp +++ b/src/modelchecker/abstraction/GameBasedMdpModelChecker.cpp @@ -218,7 +218,7 @@ namespace storm { minPlayer1Strategy = (maxPlayer1Strategy && prob01.min.first.getPlayer2States()).existsAbstract(game.getPlayer1Variables()).ite(maxPlayer1Strategy, minPlayer1Strategy); // Build the fragment of transitions that is reachable by both the min and the max strategies. - storm::dd::Bdd<Type> reachableTransitions = transitionMatrixBdd && minPlayer1Strategy && minPlayer2Strategy && maxPlayer1Strategy && maxPlayer2Strategy; + storm::dd::Bdd<Type> reachableTransitions = transitionMatrixBdd && (minPlayer1Strategy || minPlayer2Strategy) && maxPlayer1Strategy && maxPlayer2Strategy; reachableTransitions = reachableTransitions.existsAbstract(game.getNondeterminismVariables()); storm::dd::Bdd<Type> pivotStates = storm::utility::dd::computeReachableStates(game.getInitialStates(), reachableTransitions, game.getRowVariables(), game.getColumnVariables()); @@ -526,12 +526,17 @@ namespace storm { storm::dd::Add<Type, ValueType> maxResult = prob01.max.second.getPlayer1States().template toAdd<ValueType>(); storm::dd::Add<Type, ValueType> initialStatesAdd = game.getInitialStates().template toAdd<ValueType>(); + storm::dd::Bdd<Type> combinedMinPlayer1QualitativeStrategies = (prob01.min.first.getPlayer1Strategy() || prob01.min.second.getPlayer1Strategy()); + storm::dd::Bdd<Type> combinedMinPlayer2QualitativeStrategies = (prob01.min.first.getPlayer2Strategy() || prob01.min.second.getPlayer2Strategy()); + // The minimal value after qualitative checking can only be zero. It it was 1, we could have given // the result right away. ValueType minValue = storm::utility::zero<ValueType>(); MaybeStateResult<Type, ValueType> minMaybeStateResult(game.getManager().template getAddZero<ValueType>(), game.getManager().getBddZero(), game.getManager().getBddZero()); if (!maybeMin.isZero()) { minMaybeStateResult = solveMaybeStates(player1Direction, storm::OptimizationDirection::Minimize, game, maybeMin, prob01.min.second.getPlayer1States()); + minMaybeStateResult.player1Strategy &= game.getReachableStates(); + minMaybeStateResult.player2Strategy &= game.getReachableStates(); minResult += minMaybeStateResult.values; storm::dd::Add<Type, ValueType> initialStateMin = initialStatesAdd * minResult; // Here we can only require a non-zero count of *at most* one, because the result may actually be 0. @@ -540,18 +545,27 @@ namespace storm { } STORM_LOG_TRACE("Obtained quantitative lower bound " << minValue << "."); + minMaybeStateResult.player1Strategy = combinedMinPlayer1QualitativeStrategies.existsAbstract(game.getPlayer1Variables()).ite(combinedMinPlayer1QualitativeStrategies, minMaybeStateResult.player1Strategy); + minMaybeStateResult.player2Strategy = combinedMinPlayer2QualitativeStrategies.existsAbstract(game.getPlayer2Variables()).ite(combinedMinPlayer2QualitativeStrategies, minMaybeStateResult.player2Strategy); + // Check whether we can abort the computation because of the lower value. result = checkForResultAfterQuantitativeCheck<ValueType>(checkTask, storm::OptimizationDirection::Minimize, minValue); if (result) { return result; } - + + storm::dd::Bdd<Type> combinedMaxPlayer1QualitativeStrategies = (prob01.max.first.getPlayer1Strategy() || prob01.max.second.getPlayer1Strategy()); + storm::dd::Bdd<Type> combinedMaxPlayer2QualitativeStrategies = (prob01.max.first.getPlayer2Strategy() || prob01.max.second.getPlayer2Strategy()); + + // Likewise, the maximal value after qualitative checking can only be 1. If it was 0, we could have // given the result right awy. ValueType maxValue = storm::utility::one<ValueType>(); MaybeStateResult<Type, ValueType> maxMaybeStateResult(game.getManager().template getAddZero<ValueType>(), game.getManager().getBddZero(), game.getManager().getBddZero()); if (!maybeMax.isZero()) { maxMaybeStateResult = solveMaybeStates(player1Direction, storm::OptimizationDirection::Maximize, game, maybeMax, prob01.max.second.getPlayer1States(), boost::make_optional(minMaybeStateResult)); + maxMaybeStateResult.player1Strategy &= game.getReachableStates(); + maxMaybeStateResult.player2Strategy &= game.getReachableStates(); maxResult += maxMaybeStateResult.values; storm::dd::Add<Type, ValueType> initialStateMax = (initialStatesAdd * maxResult); // Unlike in the min-case, we can require a non-zero count of 1 here, because if the max was in @@ -561,6 +575,9 @@ namespace storm { } STORM_LOG_TRACE("Obtained quantitative upper bound " << maxValue << "."); + maxMaybeStateResult.player1Strategy = combinedMaxPlayer1QualitativeStrategies.existsAbstract(game.getPlayer1Variables()).ite(combinedMaxPlayer1QualitativeStrategies, maxMaybeStateResult.player1Strategy); + maxMaybeStateResult.player2Strategy = combinedMaxPlayer2QualitativeStrategies.existsAbstract(game.getPlayer2Variables()).ite(combinedMaxPlayer2QualitativeStrategies, maxMaybeStateResult.player2Strategy); + // Check whether we can abort the computation because of the upper value. result = checkForResultAfterQuantitativeCheck<ValueType>(checkTask, storm::OptimizationDirection::Maximize, maxValue); if (result) { @@ -577,8 +594,25 @@ namespace storm { // If we arrived at this point, it means that we have all qualitative and quantitative information // about the game, but we could not yet answer the query. In this case, we need to refine. + // Redirect all player 1 choices of the min strategy to that of the max strategy if this leads to a player 2 state that has the same prob. + // Get all relevant strategies. + storm::dd::Add<Type, ValueType> matrix = game.getTransitionMatrix(); + + storm::dd::Add<Type, ValueType> minResultTmp = minResult.swapVariables(game.getRowColumnMetaVariablePairs()); + storm::dd::Add<Type, ValueType> minValuesForPlayer1UnderMinP1Strategy = (matrix * minMaybeStateResult.player1Strategy.template toAdd<ValueType>() * minMaybeStateResult.player2Strategy.template toAdd<ValueType>() * minResultTmp).sumAbstract(game.getColumnVariables()).sumAbstract(game.getPlayer2Variables()).sumAbstract(game.getPlayer1Variables()); + storm::dd::Add<Type, ValueType> minValuesForPlayer1UnderMaxP1P2Strategy = (matrix * maxMaybeStateResult.player1Strategy.template toAdd<ValueType>() * maxMaybeStateResult.player2Strategy.template toAdd<ValueType>() * minResultTmp).sumAbstract(game.getColumnVariables()).sumAbstract(game.getPlayer2Variables()).sumAbstract(game.getPlayer1Variables()); + storm::dd::Add<Type, ValueType> minValuesForPlayer1UnderMaxP1Strategy = (matrix * maxMaybeStateResult.player1Strategy.template toAdd<ValueType>() * minMaybeStateResult.player2Strategy.template toAdd<ValueType>() * minResultTmp).sumAbstract(game.getColumnVariables()).sumAbstract(game.getPlayer2Variables()).sumAbstract(game.getPlayer1Variables()); + + minValuesForPlayer1UnderMinP1Strategy = prob01.min.first.getPlayer1States().ite(game.getManager().template getAddZero<ValueType>(), prob01.min.second.getPlayer1States().ite(game.getManager().template getAddOne<ValueType>(), minValuesForPlayer1UnderMinP1Strategy)); + minValuesForPlayer1UnderMaxP1Strategy = prob01.min.first.getPlayer1States().ite(game.getManager().template getAddZero<ValueType>(), prob01.min.second.getPlayer1States().ite(game.getManager().template getAddOne<ValueType>(), minValuesForPlayer1UnderMaxP1Strategy)); + + // This BDD has a 1 for every state (s) that can switch the strategy. + storm::dd::Bdd<Type> minIsGreaterOrEqual = minValuesForPlayer1UnderMinP1Strategy.greaterOrEqual(minValuesForPlayer1UnderMaxP1Strategy); + + minMaybeStateResult.player1Strategy = minIsGreaterOrEqual.ite(maxMaybeStateResult.player1Strategy, minMaybeStateResult.player1Strategy); + // Start by extending the quantitative strategies by the qualitative ones. - minMaybeStateResult.player1Strategy |= prob01.min.first.getPlayer1Strategy() || prob01.min.second.getPlayer1Strategy(); + //minMaybeStateResult.player1Strategy |= prob01.min.first.getPlayer1Strategy() || prob01.min.second.getPlayer1Strategy(); storm::dd::Bdd<Type> tmp = (prob01.min.first.getPlayer2Strategy().existsAbstract(game.getPlayer2Variables()) && prob01.min.second.getPlayer2Strategy().existsAbstract(game.getPlayer2Variables())); STORM_LOG_ASSERT(tmp.isZero(), "wth?");