dating from the English Bill of Rights 1689: the executive is, of course, responsible to the legislature in Papua New Guinea's Parliament. Developing the underlying law The Supreme Court (together with the National Court) has a special responsibility for developing the underlying law, i.e. the common law of Papua New Guinea, having resort to those rules of local custom in various regions of the country which may be taken to be common to the whole country. The responsibility has been given additional express warrant in the Underlying Law Act 2000 which purports to mandate greater attention by the courts to custom and the development of customary law as an important component of the underlying law. In practice the courts have found great difficulty in applying the vastly differing custom of the many traditional societies of the country in a modern legal system and the development of the customary law according to indigenous Melanesian conceptions of justice and equity has been less thorough than may have been anticipated in 1975; the Underlying Law Act does not yet appear to have had significant effect. An ardent proponent of the underlying law, David Gonol in his book titled The Underlying Law of Papua New Guinea: An inquiry into adoption and application of customary law expounded at length on these issues. Further, in the 2017 Third National Underlying Law Conference, many notable speakers expressed similar sentiments that the underlying law is not being developed at sufficient pace. Hierarchy of precedent The hierarchy of case law precedent is that while the Supreme Court has authority to overrule any case authority, its own decisions are binding on the lower courts as are the decisions of the English superior courts prior to Papua New Guinea's independence, which are deemed to be part of Papua New Guinea's underlying law. Decisions of the pre-Independence Supreme Court of Papua New Guinea are deemed to be foreign law, equivalent in authority to decisions by any foreign court with a similar legal system, and of persuasive value only. The principle of the mere persuasiveness of overseas (and pre-Independence Papua New Guinea) authority vis-à-vis the binding authority of pre-1975 English authority has been applied many times in, for example, Toglai Apa and Bomai Siune v The State [1995] PNGLR 43 that it is bound to follow the English House of Lords case of Rookes v Barnard [1964] AC 1129 on the ineligibility of