微分形式及其应用

ThisisafreetranslationofasetofnotespublishedoriginallyinPortuguesein 1971.TheyweretranslatedforacourseintheCollegeofDifferentialGeome- try,ICTP,Trieste,1989.IntheEnglishtranslationweomittedachapteron theFrobeniustheoremandanappendixonthenonexistenceofa