The legal analyst must put some of the ideational material of policy and principle into the law .
法律分析者谅必要将思考政策和原理的某些材料置于法律之中。
To sum up , newspaper headlines play a vital role in representing the world ( ideational function ) through transitivity system and voice , constructing social identities and establishing social relations ( interpersonal function ) through mood and modality , and achieving texture ( textual function ) through thematization and information structure .