private IQTree liftBindingAfterPropagatingCondition(IQTree childIQTree, VariableGenerator variableGenerator, IQProperties currentIQProperties) { IQTree liftedChildIQTree = childIQTree.liftBinding(variableGenerator); QueryNode childRoot = liftedChildIQTree.getRootNode(); if (childRoot instanceof ConstructionNode) return liftBinding((ConstructionNode) childRoot, (UnaryIQTree) liftedChildIQTree, currentIQProperties, variableGenerator); else if (liftedChildIQTree.isDeclaredAsEmpty()) { return liftedChildIQTree; } else return iqFactory.createUnaryIQTree(this, liftedChildIQTree, currentIQProperties.declareLifted()); }