public void fillInGenSet(Collection in, Collection gen) {
		if (this instanceof LocalVarOperator) {
			LocalVarOperator varOp = (LocalVarOperator) this;
			if (varOp.isRead() && in != null)
				in.add(varOp.getLocalInfo());
			if (gen != null)
				gen.add(varOp.getLocalInfo());
		}
		for (int i = 0; i < subExpressions.length; i++)
			subExpressions[i].fillInGenSet(in, gen);
	}