Preface |
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A Guide to Closure Operations in Commutative Algebra |
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1 | (1) |
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2 What Is a Closure Operation? |
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2 | (5) |
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2 | (4) |
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2.2 Not-quite-closure Operations |
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6 | (1) |
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3 Constructing Closure Operations |
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7 | (3) |
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3.1 Standard Constructions |
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7 | (2) |
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3.2 Common Closures as Iterations of Standard Constructions |
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9 | (1) |
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10 | (12) |
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4.1 Star-, Semi-prime, and Prime Operations |
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10 | (6) |
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4.2 Closures Defined by Properties of (Generic) Forcing Algebras |
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16 | (1) |
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17 | (1) |
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4.4 Axioms Related to the Homological Conjectures |
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18 | (2) |
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4.5 Tight Closure and Its Imitators |
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20 | (1) |
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4.6 (Homogeneous) Equational Closures and Localization |
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21 | (1) |
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5 Reductions, Special Parts of Closures, Spreads, and Cores |
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22 | (3) |
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5.1 Nakayama Closures and Reductions |
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22 | (1) |
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5.2 Special Parts of Closures |
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23 | (2) |
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6 Classes of Rings Defined by Closed Ideals |
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25 | (4) |
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6.1 When Is the Zero Ideal Closed? |
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26 | (1) |
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6.2 When Are 0 and Principal Ideals Generated by Non-zerodivisors Closed? |
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26 | (1) |
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6.3 When Are Parameter Ideals Closed (Where R Is Local)? |
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27 | (1) |
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6.4 When Is Every Ideal Closed? |
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28 | (1) |
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7 Closure Operations on (Sub)modules |
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29 | (10) |
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31 | (8) |
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39 | (2) |
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2 Characteristic p Preliminaries |
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41 | (3) |
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2.1 The Frobenius Endomorphism |
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41 | (1) |
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42 | (2) |
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44 | (6) |
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3.1 Test Ideals of Map-pairs |
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44 | (3) |
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47 | (1) |
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3.3 Test Ideals in Gorenstein Local Rings |
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48 | (2) |
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4 Connections with Algebraic Geometry |
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50 | (7) |
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4.1 Characteristic 0 Preliminaries |
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50 | (2) |
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4.2 Reduction to Characteristic p >0 and Multiplier Ideals |
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52 | (2) |
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4.3 Multiplier Ideals of Pairs |
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54 | (2) |
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4.4 Multiplier Ideals vs. Test Ideals of Divisor Pairs |
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56 | (1) |
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5 Tight Closure and Applications of Test Ideals |
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57 | (6) |
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5.1 The Briancon--Skoda Theorem |
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61 | (1) |
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5.2 Tight Closure for Modules and Test Elements |
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61 | (2) |
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6 Test Ideals for Pairs (R, at) and Applications |
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63 | (5) |
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6.1 Initial Definitions of at-test Ideals |
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63 | (2) |
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65 | (1) |
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66 | (2) |
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7 Generalizations of Pairs: Algebras of Maps |
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68 | (3) |
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8 Other Measures of Singularities in Characteristic p |
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71 | (30) |
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71 | (1) |
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72 | (1) |
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8.3 F-signature and F-splitting Ratio |
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73 | (2) |
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8.4 Hilbert--Kunz(--Monsky) Multiplicity |
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75 | (3) |
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8.5 F-ideals, F-stable Submodules, and F-pure Centers |
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78 | (2) |
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A Canonical Modules and Duality |
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80 | (1) |
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A.1 Canonical Modules, Cohen--Macaulay and Gorenstein Rings |
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80 | (1) |
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81 | (2) |
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83 | (2) |
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C Glossary and Diagrams on Types of Singularities |
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85 | (1) |
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86 | (15) |
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Finite-dimensional Vector Spaces with Frobenius Action |
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101 | (1) |
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2 A Noncommutative Principal Ideal Domain |
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102 | (2) |
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3 Ideal Theory and Divisibility in Noncommutative PIDs |
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104 | (5) |
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107 | (2) |
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4 Matrix Transformations over Noncommutative PIDs |
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109 | (2) |
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5 Module Theory over Noncommutative PIDs |
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111 | (3) |
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6 Computing the Invariant Factors |
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114 | (7) |
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6.1 Injective Frobenius Actions on Finite Dimensional Vector Spaces over a Perfect Field |
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118 | (3) |
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121 | (8) |
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Finiteness and Homological Conditions in Commutative Group Rings |
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129 | (1) |
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130 | (3) |
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3 Homological Dimensions and Regularity |
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133 | (3) |
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4 Zero Divisor Controlling Conditions |
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136 | (9) |
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145 | (2) |
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147 | (4) |
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3 Pullbacks of Noetherian Rings |
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151 | (2) |
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4 Pullbacks of Prufer Rings |
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153 | (3) |
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5 Pullbacks of Coherent Rings |
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156 | (3) |
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6 The n-generator Property in Pullbacks |
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159 | (6) |
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7 Factorization in Pullbacks |
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165 | (6) |
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Noetherian Rings without Finite Normalization |
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171 | (3) |
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2 Normalization and Completion |
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174 | (2) |
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176 | (9) |
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4 Examples Birationally Dominating a Local Ring |
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185 | (4) |
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189 | (1) |
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6 Strongly Twisted Subrings of Local Noetherian Domains |
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190 | (15) |
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Krull Dimension of Polynomial and Power Series Rings |
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205 | (2) |
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2 A Key Property of R[ x] |
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207 | (1) |
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208 | (4) |
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4 Additional Applications |
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212 | (5) |
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5 The Dimension of Power Series Rings |
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217 | (4) |
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The Projective Line over the Integers |
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221 | (1) |
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2 Definitions and Background |
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222 | (4) |
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3 The Coefficient Subset and Radical Elements of Proj(Z[ h, k]) |
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226 | (3) |
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4 The Conjecture for Proj(Z[ h, k]) and Previous Partial Results |
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229 | (3) |
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5 New Results Supporting the Conjecture |
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232 | (6) |
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238 | (3) |
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241 | (2) |
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2 Survey of Past Research on Zero Divisor Graphs |
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243 | (7) |
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2.1 Beck's Zero Divisor Graph |
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243 | (1) |
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2.2 Anderson and Livingston's Zero Divisor Graph |
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244 | (2) |
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2.3 Mulay's Zero Divisor Graph |
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246 | (1) |
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2.4 Other Zero Divisor Graphs |
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247 | (3) |
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250 | (20) |
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4 Graph Homomorphisms and Graphs Associated to Modules |
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270 | (3) |
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273 | (9) |
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282 | (6) |
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282 | (4) |
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286 | (2) |
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7 Chromatic Numbers and Clique Numbers |
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288 | (13) |
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7.1 Chromatic/Clique Number 1 |
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289 | (1) |
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7.2 Chromatic/Clique Number 2 |
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290 | (1) |
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7.3 Chromatic/Clique Number 3 |
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290 | (3) |
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A Tables for Example 3.14 |
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293 | (2) |
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295 | (6) |
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A Closer Look at Non-unique Factorization via Atomic Decay and Strong Atoms |
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301 | (2) |
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2 Strong Atoms and Prime Ideals |
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303 | (2) |
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3 Atomic Decay in the Ring of Integers of an Algebraic Number Field |
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305 | (4) |
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4 The Fundamental Example of the Failure of Unique Factorization: Z[ √-5] |
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309 | (2) |
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5 A More Striking Example |
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311 | (3) |
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6 Concluding Remarks and Questions |
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314 | |