PropositionLevel propositionLevel = (PropositionLevel) graph.getGraphLevel(graph.size()-1);
//into which we add the preconditions for this action
propositionLevel.addPropositions(concreteOperators[i].getPreconds());
//We then create an action level to contain this action
ActionLevel actionLevel = new ActionLevel();
actionLevel.addAction(concreteOperators[i]);
graph.addGraphLevel(actionLevel);
//And create another proposition level for its effects
PropositionLevel propositionLevel2 = new PropositionLevel();
propositionLevel2.addPropositions(concreteOperators[i].getEffects());