Modern Applications Of Logic, In Mathematics, Theoretical Computer Science, And Linguistics, Require Combined Systems Involving Many Different Logics Working Together. In This Book The Author Offers A Basic Methodology For Combining-or Fibring-systems. This Means That Many Existing Complex Systems Can Be Broken Down Into Simpler Components, Hence Making Them Much Easier To Manipulate. Using This Methodology The Book Discusses Ways Of Obtaining A Wide Variety Of Multimodal, Modal Intuitionistic, Modal Substructural And Fuzzy Systems In A Uniform Way. It Also Covers Self-fibred Languages Which Allow Formulae To Apply To Themselves. The Book Also Studies Sufficient Conditions For Transferring Properties Of The Component Logics Into Properties Of The Combined System.