1. Sets and Relations
m m 1
I. Groups and Subgroups m m
2. Introduction and Examples 4 m m
3. Binary Operations 7 m
4. Isomorphic Binary Structures 9 m m
5. Groups 13
6. Subgroups 17
7. Cyclic Groups 21
m m
8. Generators and Cayley Digraphs 24 m m m
II. Permutations, Cosets, and Direct Products m m m m
9. Groups of Permutations 26 m m
10. Orbits, Cycles, and the Alternating Groups m m m m m
30
11. Cosets and the Theorem of Lagrange
m 34 m m m m
12. Direct Products and Finitely Generated Abelian Groups 37
m m m m m m
13. Plane Isometries 42
m
III. Homomorphisms and Factor Groups m m m
14. Homomorphisms 44
15. Factor Groups 49 m
16. Factor-Group Computations and Simple Groups m m m m 53
17. Group Action on a Set 58
m m m m
18. Applications of G-Sets to Counting 61 m m m m
IV. Rings and Fields m m
19. Rings and Fields 63
m m
20. Integral Domains 68 m
21. Fermat’s and Euler’s Theorems 72 m m m
22. The Field of Quotients of an Integral Domain 74
m m m m m m m
23. Rings of Polynomials 76
m m
24. Factorization of Polynomials over a Field 79 m m m m m
25. Noncommutative Examples 85 m
26. Ordered Rings and Fields 87 m m m
V. Ideals and Factor Rings m m m
27. Homomorphisms and Factor Rings m m m 89
28. Prime and Maximal Ideals
m 94 m m
,29. Gröbner Bases for Ideals
m m m 99
, VI. Extension Fields m
30. Introduction to Extension Fields m m m 103
31. Vector Spaces 107 m
32. Algebraic Extensions 111 m
33. Geometric Constructions 115 m
34. Finite Fields 116
m
VII. Advanced Group Theory m m
35. Isomorphism Theorems 117 m
36. Series of Groups 119
m m
37. Sylow Theorems 122
m
38. Applications of the Sylow Theory m m m m 124
39. Free Abelian Groups 128
m m
40. Free Groups 130
m
41. Group Presentations 133
m
VIII. Groups in Topology m m
42. Simplicial Complexes and Homology Groups 136
m m m m
43. Computations of Homology Groups 138 m m m
44. More Homology Computations and Applications
m 140 m m m
45. Homological Algebra 144 m
IX. Factorization
46. Unique Factorization Domains 148
m m
47. Euclidean Domains 151 m
48. Gaussian Integers and Multiplicative Norms
m m m m 154
X. Automorphisms and Galois Theory m m m
49. Automorphisms of Fields 159 m m
50. The Isomorphism Extension Theorem
m m m 164
51. Splitting Fields 165 m
52. Separable Extensions 167 m
53. Totally Inseparable Extensions
m 171 m
54. Galois Theory 173 m
55. Illustrations of Galois Theory 176 m m m
56. Cyclotomic Extensions 183 m
57. Insolvability of the Quintic 185 m m m
APPENDIX Matrix Algebra m m m m 187
iv