In a specific sense, however, regulæ juris are certain fundamental laws in the form of axioms found in the "Corpus Juris", eleven inserted by Gregory IX at the end of the fifth Book of Decretals, eighty-eight by Boniface VIII in the last title of Liber Sextus Decretalium. These rules are an exposition of several laws on the same subject, conclusions or deductions, rather than principles of law drawn from constitutions or decisions, and consequently reserved to the last title of the two books mentioned, in imitation of Justinian in the "Digest" (L, l, tit. 17).