+ return _preconditions.size() == 0 && !_executed;
+}
+
+void Node::execute(){
+ if(_executed)
+ cerr << "Already executed " << _action->name() << endl;
+ if ((_preconditions.size() != 0) || _executed)
+ return;
+
+ _executed = true;
+ int value = _action->execute();
+ _effects = _action->effects(value);
+
+}
+
+const std::vector<Node*>& Node::children() const{
+ return _children;
+}
+StartNode::StartNode(const Literals& init){
+ EffectsMap initial;
+ initial[0] = init;
+ _action = new Action("start",Preconditions(),"", initial);
+ _executed = true;
+ _effects = init;