a research about principle of justice and equity

principle of justice and equity is a term, although it is seen in recent jurisprudents' writings, which have not been explained clearly at all. therefore, some of the jurisprudents do not accept this term as a principle; some others accept it as a principle and consider its implementation in case of being a special reason; and other group of jurisprudents accept it as a principle but limited to a specific subject. in this paper, it is tried to search in legal and jurisprudential sources collect valid documents to prove this principle, and then to specify framework and scope of its implication to reach an effective rule in the process of inference obviously.