Definition: the dictum of Panini about rules in his second, third and fourth quarters (Padas) of the eighth Adhyaya being invalid to (viz. not seen by) all the previous rules in the first seven chapters and the first quarter of the eighth as laid down by him in the rule पूर्वत्रासिद्धम् VIII.2.1. The rule पूर्वत्रासिद्धम् is taken also as a governing rule i.e. अधिकार laying down that in the last three quarters also of his grammar, a subsequent rule is invalid to the preceding rule. The purpose of this dictum is to prohibit the application of the rules in the last three quarters as also that of a subsequent rule in the last three quarters, before all such preceding rules, as are applicable in the formation of a word, have been given effect to; cf. एवमिहापि पर्वेत्रासिद्धवचनं अादेशलक्षणप्रतिषेधार्थमुत्सर्गलक्षणभावार्थं च M.Bh. on P. VIII.2.1 Vart. 8.