ItemTreePtr RuleIntroductionSolver::compute()
{
const auto nodeStackElement = app.getPrinter().visitNode(decomposition);
assert(decomposition.getChildren().size() == 1);
Decomposition& childNode = **decomposition.getChildren().begin();
ItemTreePtr childResult = childNode.getSolver().compute();
ItemTreePtr result;
if(childResult) {
result = extendRoot(childResult);
assert(childResult->getChildren().empty() == false);
for(const ItemTreePtr& childCandidate : childResult->getChildren()) {
// Make introducedAtom false
ItemTreeNode::Items candidateItems = childCandidate->getNode()->getItems();
ItemTreeNode::Items candidateAuxItems = childCandidate->getNode()->getAuxItems();
// Calculate false atoms of this candidate
Hypergraph::Vertices candidateFalseAtoms;
std::set_symmetric_difference(decomposition.getNode().getBag().begin(), decomposition.getNode().getBag().end(), candidateItems.begin(), candidateItems.end(), std::inserter(candidateFalseAtoms, candidateFalseAtoms.begin()));
const bool introducedRuleDisappears = doesIntroducedRuleDisappear(candidateItems);
if(introducedRuleDisappears || isIntroducedRuleSatisfied(candidateItems, candidateFalseAtoms))
candidateAuxItems.insert(introducedRule);
ItemTreePtr candidate = extendCandidate(std::move(candidateItems), std::move(candidateAuxItems), childCandidate);
for(const ItemTreePtr& childCertificate : childCandidate->getChildren()) {
ItemTreeNode::Items certificateItems = childCertificate->getNode()->getItems();
ItemTreeNode::Items certificateAuxItems = childCertificate->getNode()->getAuxItems();
if(introducedRuleDisappears)
certificateAuxItems.insert(introducedRule);
else {
// Calculate false atoms of this certificate
Hypergraph::Vertices certificateFalseAtoms;
std::set_symmetric_difference(decomposition.getNode().getBag().begin(), decomposition.getNode().getBag().end(), certificateItems.begin(), certificateItems.end(), std::inserter(certificateFalseAtoms, certificateFalseAtoms.begin()));
if(isIntroducedRuleSatisfied(certificateItems, certificateFalseAtoms))
certificateAuxItems.insert(introducedRule);
}
candidate->addChildAndMerge(extendCertificate(std::move(certificateItems), std::move(certificateAuxItems), childCertificate));
}
result->addChildAndMerge(std::move(candidate));
}
assert(!decomposition.isRoot());
if(result->finalize(app, false, app.isPruningDisabled() == false || decomposition.isRoot()) == false)
result.reset();
}
app.getPrinter().solverInvocationResult(decomposition, result.get());
return result;
}
void Solver::handleRowCandidate(long costBound)
{
// ++models;
assert(asyncResult);
const Clasp::Model& m = asyncResult->model();
// Get items {{{
ItemTreeNode::Items items;
asp_utils::forEachTrue(m, itemAtomInfos, [&items](const GringoOutputProcessor::ItemAtomArguments& arguments) {
items.insert(arguments.item);
});
ItemTreeNode::Items auxItems;
asp_utils::forEachTrue(m, auxItemAtomInfos, [&auxItems](const GringoOutputProcessor::AuxItemAtomArguments& arguments) {
auxItems.insert(arguments.item);
});
ASP_CHECK(std::find_if(items.begin(), items.end(), [&auxItems](const String& item) {
return auxItems.find(item) != auxItems.end();
}) == items.end(), "Items and auxiliary items not disjoint");
// }}}
// FIXME Do proper cost computations, not this item-set cardinality proof of concept
// Compute cost {{{
// ASP_CHECK(asp_utils::countTrue(m, costAtomInfos) <= 1, "More than one true cost/1 atom");
// long cost = 0;
// asp_utils::forFirstTrue(m, costAtomInfos, [&cost](const GringoOutputProcessor::CostAtomArguments& arguments) {
// cost = arguments.cost;
// });
// node->setCost(cost);
long cost = items.size();
for(const auto& row : getCurrentRowCombination()) {
const auto& oldItems = row->getItems();
ItemTreeNode::Items intersection;
std::set_intersection(items.begin(), items.end(), oldItems.begin(), oldItems.end(), std::inserter(intersection, intersection.begin()));
cost += row->getCost() - intersection.size();
}
// }}}
if(cost >= costBound) {
// ++discardedModels;
newestRow = itemTree->getChildren().end();
return;
}
assert(itemTree);
// Create item tree node {{{
std::shared_ptr<ItemTreeNode> node(new ItemTreeNode(std::move(items), std::move(auxItems), {getCurrentRowCombination()}));
// }}}
if(!app.isOptimizationDisabled()) {
// Set cost {{{
node->setCost(cost);
// }}}
// Set current cost {{{
// ASP_CHECK(asp_utils::countTrue(m, currentCostAtomInfos) <= 1, "More than one true currentCost/1 atom");
// ASP_CHECK(asp_utils::countTrue(m, currentCostAtomInfos) == 0 || asp_utils::countTrue(m, costAtomInfos) == 1, "True currentCost/1 atom without true cost/1 atom");
// long currentCost = 0;
// asp_utils::forFirstTrue(m, currentCostAtomInfos, [¤tCost](const GringoOutputProcessor::CurrentCostAtomArguments& arguments) {
// currentCost = arguments.currentCost;
// });
// node->setCurrentCost(currentCost);
node->setCurrentCost(node->getItems().size());
// }}}
// Possibly update cost of root {{{
itemTree->getNode()->setCost(std::min(itemTree->getNode()->getCost(), cost));
// }}}
}
// Add node to item tree {{{
//ItemTree::Children::const_iterator newChild = itemTree->addChildAndMerge(ItemTree::ChildPtr(new ItemTree(std::move(node))));
newestRow = itemTree->costChangeAfterAddChildAndMerge(ItemTree::ChildPtr(new ItemTree(std::move(node))));
// }}}
//if(newChild != itemTree->getChildren().end())
// newestRow = newChild;
}
ItemTreePtr AtomIntroductionSolver::compute()
{
const auto nodeStackElement = app.getPrinter().visitNode(decomposition);
assert(decomposition.getChildren().size() == 1);
Decomposition& childNode = **decomposition.getChildren().begin();
ItemTreePtr childResult = childNode.getSolver().compute();
ItemTreePtr result;
if(childResult) {
result = extendRoot(childResult);
assert(childResult->getChildren().empty() == false);
// Find out which rules are satisfied by setting introducedAtom to true or false, respectively, and which disappear from the reduct by setting introducedAtom to true.
// TODO unordered_set?
Rules rulesSatisfiedByTrue;
Rules rulesSatisfiedByFalse;
Rules rulesDisappearingByTrue;
for(String bagElement : decomposition.getNode().getBag()) {
AtomsInRule::const_iterator it = heads.find(bagElement);
if(it != heads.end() && it->second.find(introducedAtom) != it->second.end())
rulesSatisfiedByTrue.insert(bagElement);
it = positiveBody.find(bagElement);
if(it != positiveBody.end() && it->second.find(introducedAtom) != it->second.end())
rulesSatisfiedByFalse.insert(bagElement);
it = negativeBody.find(bagElement);
if(it != negativeBody.end() && it->second.find(introducedAtom) != it->second.end()) {
rulesSatisfiedByTrue.insert(bagElement);
rulesDisappearingByTrue.insert(bagElement);
}
}
// Guess node to extend at depth 1
for(const ItemTreePtr& childCandidate : childResult->getChildren()) {
// Make introducedAtom false
ItemTreeNode::Items candidateItems = childCandidate->getNode()->getItems();
ItemTreeNode::Items candidateAuxItems = childCandidate->getNode()->getAuxItems();
// Add satisfied rules
candidateAuxItems.insert(rulesSatisfiedByFalse.begin(), rulesSatisfiedByFalse.end());
ItemTreePtr candidate = extendCandidate(std::move(candidateItems), std::move(candidateAuxItems), childCandidate);
for(const ItemTreePtr& childCertificate : childCandidate->getChildren()) {
ItemTreeNode::Items certificateItems = childCertificate->getNode()->getItems();
ItemTreeNode::Items certificateAuxItems = childCertificate->getNode()->getAuxItems();
// Add satisfied rules
certificateAuxItems.insert(rulesSatisfiedByFalse.begin(), rulesSatisfiedByFalse.end());
candidate->addChildAndMerge(extendCertificate(std::move(certificateItems), std::move(certificateAuxItems), childCertificate));
}
result->addChildAndMerge(std::move(candidate));
// Make introducedAtom true
candidateItems = childCandidate->getNode()->getItems();
candidateItems.insert(introducedAtom);
candidateAuxItems = childCandidate->getNode()->getAuxItems();
// Add satisfied rules
candidateAuxItems.insert(rulesSatisfiedByTrue.begin(), rulesSatisfiedByTrue.end());
candidate = extendCandidate(std::move(candidateItems), std::move(candidateAuxItems), childCandidate);
for(const ItemTreePtr& childCertificate : childCandidate->getChildren()) {
// Make introducedAtom false in certificate (and add "smaller" flag)
ItemTreeNode::Items certificateItems = childCertificate->getNode()->getItems();
ItemTreeNode::Items certificateAuxItems = childCertificate->getNode()->getAuxItems();
certificateAuxItems.emplace("smaller");
certificateAuxItems.insert(rulesDisappearingByTrue.begin(), rulesDisappearingByTrue.end());
certificateAuxItems.insert(rulesSatisfiedByFalse.begin(), rulesSatisfiedByFalse.end());
candidate->addChildAndMerge(extendCertificate(std::move(certificateItems), std::move(certificateAuxItems), childCertificate));
// Make introducedAtom true in certificate
certificateItems = childCertificate->getNode()->getItems();
certificateItems.insert(introducedAtom);
certificateAuxItems = childCertificate->getNode()->getAuxItems();
certificateAuxItems.insert(rulesSatisfiedByTrue.begin(), rulesSatisfiedByTrue.end());
candidate->addChildAndMerge(extendCertificate(std::move(certificateItems), std::move(certificateAuxItems), childCertificate));
}
result->addChildAndMerge(std::move(candidate));
}
assert(!decomposition.isRoot());
if(result->finalize(app, false, app.isPruningDisabled() == false || decomposition.isRoot()) == false)
result.reset();
}
app.getPrinter().solverInvocationResult(decomposition, result.get());
return result;
}