LocalizeRingForHomalg Localize Commutative homalg Rings at Maximal Ideals Version 2017.09.02 September 2015 Mohamed Barakat Markus Lange-Hegermann Vinay Wagh This manual is best viewed as an HTML document. The latest version is available online at: http://homalg.math.rwth-aachen.de/~markus/LocalizeRingForHomalg/chap0.html An offline version should be included in the documentation subfolder of the package. Mohamed Barakat Email: mailto:barakat@mathematik.uni-kl.de Homepage: http://www.mathematik.uni-kl.de/~barakat/ Address: Department of Mathematics, University of Kaiserslautern, 67653 Kaiserslautern, Germany Markus Lange-Hegermann Email: mailto:markus.lange.hegermann@rwth-aachen.de Homepage: http://wwwb.math.rwth-aachen.de/~markus Address: Lehrstuhl B für Mathematik, RWTH Aachen, Templergraben 64, 52056 Aachen, Germany Vinay Wagh Email: mailto:waghoba@gmail.com Homepage: http://www.iitg.ernet.in/vinay.wagh/ Address: E-102, Department of Mathematics, Indian Institute of Technology Guwahati, Guwahati, Assam, India. PIN: 781 039. ------------------------------------------------------- Copyright © 2009-2015 by Mohamed Barakat and Markus Lange-Hegermann This package may be distributed under the terms and conditions of the GNU Public License Version 2. ------------------------------------------------------- Acknowledgements We would like to thank the Aachen forest for being such a nice place for jogging. ------------------------------------------------------- Contents (LocalizeRingForHomalg) 1 Introduction 1.1 What is the Role of the LocalizeRingForHomalg Package in the homalg Project? 1.2 Functionality 1.3 The Math Behind This Package 1.4 Which Ring to Use? 2 Installation of the LocalizeRingForHomalg Package 3 Quick Start 3.1 Localization of ℤ 4 Localize Rings 4.1 Category and Representations 4.1-1 IsHomalgLocalRingRep 4.1-2 IsHomalgLocalRingElementRep 4.1-3 IsHomalgLocalMatrixRep 4.2 Rings: Attributes 4.2-1 GeneratorsOfMaximalLeftIdeal 4.2-2 GeneratorsOfMaximalRightIdeal 4.3 Operations and Functions 4.3-1 AssociatedGlobalRing 4.3-2 AssociatedGlobalRing 4.3-3 AssociatedGlobalRing 4.3-4 Numerator 4.3-5 Numerator 4.3-6 Denominator 4.3-7 Denominator 4.3-8 Name 4.3-9 SetMatElm 4.3-10 AddToMatElm 4.3-11 MatElmAsString 4.3-12 MatElm 4.3-13 Cancel 4.3-14 LocalizeAt 4.3-15 LocalizeAtZero 4.3-16 LocalizePolynomialRingAtZeroWithMora 4.3-17 HomalgLocalRingElement 4.3-18 HomalgLocalMatrix 5 Examples 5.1 An Easy Polynomial Example 5.2 Hom(Hom(-,Z128),Z16) 5.3 ResidueClass 5.4 Testing the Intersection Formula A Overview of the LocalizeRingForHomalg Package Source Code A.1 The generic Methods A.1-1 BasisOfRowModule A.1-2 DecideZeroRows A.1-3 SyzygiesGeneratorsOfRows A.2 The Local Decide Zero trick A.2-1 DecideZeroRows A.3 Tools