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1 | (18) |
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1.1 Definition of the Tensor Product |
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1 | (3) |
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1.2 Properties of the Tensor Product |
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4 | (8) |
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4 | (1) |
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4 | (3) |
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1.2.3 Kronecker Product of Matrices |
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7 | (2) |
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1.2.4 Tensor Product and Homomorphisms |
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9 | (1) |
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1.2.5 Extension of Scalars |
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10 | (1) |
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1.2.6 Trace and Restriction of Scalars |
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11 | (1) |
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1.3 Symmetric and Alternating Powers |
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12 | (3) |
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1.3.1 Symmetric and Alternating Squares |
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12 | (1) |
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1.3.2 Tensor, Symmetric and Exterior Algebras |
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13 | (2) |
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1.4 Tensor Product over an Algebra |
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15 | (4) |
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19 | (22) |
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2.1 Generalities on Representations |
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19 | (4) |
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19 | (1) |
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2.1.2 General Representations |
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20 | (3) |
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23 | (6) |
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23 | (1) |
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2.2.2 Transitive Representations |
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24 | (1) |
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2.2.3 Classification of Transitive Representations |
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25 | (1) |
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26 | (3) |
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2.3 Linear Representations |
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29 | (12) |
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29 | (6) |
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2.3.2 Finite Groups: The Group Algebra |
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35 | (6) |
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3 Characteristic 0 Representations |
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41 | (50) |
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3.1 Preliminary: 1/|G| ΣgεGg |
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41 | (3) |
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41 | (1) |
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42 | (2) |
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44 | (1) |
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44 | (16) |
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44 | (3) |
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3.2.2 Orthogonality Relations and First Applications |
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47 | (7) |
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54 | (4) |
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3.2.4 From Permutations to Characters |
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58 | (2) |
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3.3 Structure of the Group Algebra |
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60 | (4) |
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3.3.1 A Product of Endomorphism Algebras |
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60 | (2) |
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3.3.2 Canonical Decomposition of a Representation |
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62 | (2) |
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64 | (2) |
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3.5 Center and Action of Cyclotomic Galois Groups |
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66 | (9) |
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67 | (1) |
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3.5.2 Extending and Restricting Scalars |
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68 | (4) |
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3.5.3 Action of (Z/eGZ)× and of Galois Groups of Cyclotomic Extensions |
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72 | (3) |
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3.6 More on a Splitting Field and First Applications |
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75 | (4) |
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75 | (2) |
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77 | (1) |
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78 | (1) |
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3.7 Some Arithmetical Properties of Characters |
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79 | (12) |
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3.7.1 Characters and Integrality |
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79 | (3) |
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3.7.2 Applications: Two Theorems of Burnside |
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82 | (9) |
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4 PLAYING with the BASE FIELD |
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91 | (20) |
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4.1 Analysis of an Irreducible Module |
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91 | (9) |
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4.1.1 An Example: The Quaternion Group Q8 |
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91 | (3) |
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4.1.2 Scalars of an Irreducible Module |
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94 | (3) |
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97 | (3) |
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4.2 Complements on Rationality |
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100 | (11) |
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4.2.1 Group of Characters and Rationality |
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100 | (3) |
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4.2.2 Reflections and Rationality |
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103 | (2) |
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4.2.3 Questions of Rationality over R |
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105 | (6) |
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111 | (20) |
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111 | (10) |
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111 | (1) |
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112 | (7) |
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119 | (2) |
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5.2 Induction and Restriction in Characteristic Zero |
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121 | (10) |
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5.2.1 Induction and Normal Subgroups |
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121 | (1) |
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5.2.2 Induction and Restriction for Class Functions |
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122 | (4) |
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5.2.3 Application of Induction to an Example |
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126 | (5) |
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6 Brauer's Theorem and Some Applications |
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131 | (24) |
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131 | (2) |
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6.2 Brauer's Characterization of Characters |
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133 | (7) |
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6.2.1 Statement and First Consequences |
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133 | (2) |
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6.2.2 Proof of Brauer's Theorem |
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135 | (5) |
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6.3 Fusion and Isometries |
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140 | (4) |
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6.3.1 π-elements and Class Functions |
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141 | (1) |
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6.3.2 π-Control Subgroups |
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141 | (3) |
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6.4 Some Fundamental Theorems about Finite Groups |
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144 | (11) |
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6.4.1 Existence of a Normal π-Complement |
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145 | (1) |
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6.4.2 π-trivial Intersection Subgroups |
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146 | (1) |
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147 | (8) |
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7 Graded Representation and Characters |
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155 | (24) |
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7.1 Graded Vector Spaces, Algebras, Modules |
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155 | (12) |
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7.1.1 Graded Vector Spaces |
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155 | (2) |
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7.1.2 Graded Algebras and Modules |
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157 | (3) |
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160 | (1) |
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7.1.4 Free Graded Modules |
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161 | (3) |
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7.1.5 Polynomial Algebras and Noether Parameters |
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164 | (3) |
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7.2 Graded Characters of Graded kG-modules |
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167 | (12) |
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7.2.1 Notation and Definitions |
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167 | (2) |
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7.2.2 Isotypic Components of the Symmetric Algebra |
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169 | (3) |
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7.2.3 Computations with Power Series |
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172 | (2) |
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174 | (1) |
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7.2.5 Complement: Reflection Groups |
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175 | (4) |
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179 | (38) |
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8.1 The Drinfeld Double of a Finite Group as an Algebra |
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179 | (10) |
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8.1.1 The Semidirect Product of kG and Its Dual |
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180 | (3) |
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8.1.2 A Description of DkGmod |
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183 | (3) |
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8.1.3 On the Center Z(DkG) and Central Functions Again |
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186 | (3) |
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8.2 Hopf Algebras: An Introduction from Scratch |
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189 | (9) |
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8.2.1 Notation for Multiple Tensor Products |
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189 | (2) |
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8.2.2 Algebras, Coalgebras, Bialgebras, Hopf Algebras |
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191 | (5) |
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8.2.3 On Algebra Representations of a Hopf Algebra |
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196 | (2) |
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8.3 The Drinfeld Double as a Ribbon Hopf Algebra |
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198 | (10) |
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8.3.1 Universal R-matrix for DkG |
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198 | (3) |
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8.3.2 The Category DtGmod is a Ribbon Category |
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201 | (1) |
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8.3.3 A Description of 0tcmod as a Ribbon Category |
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202 | (6) |
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208 | (9) |
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8.4.1 The Automorphisms S, Ω, Δn |
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208 | (3) |
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8.4.2 Action of GL2(Z/eGZ) |
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211 | (1) |
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8.4.3 The Verlinde Formula |
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212 | (5) |
Appendix A Basics on Finite Groups |
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217 | (4) |
Appendix B Assumed Results on Galois Theory |
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221 | (4) |
Appendix C Integral Elements |
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225 | (4) |
Appendix D Noetherian Rings and Modules |
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229 | (4) |
Appendix E The Language of Categories and Functors |
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233 | (8) |
Bibliography |
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241 | (2) |
Index |
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243 | |