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Preface | |
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Algebraic preliminaries | |
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Groups, fields and vector spaces | |
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Groups | |
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Fields | |
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Vector spaces | |
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The axiom of choice, and Zorn's lemma | |
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The axiom of choice | |
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Zorn's lemma | |
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The existence of a basis | |
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Rings | |
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Rings | |
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Integral domains | |
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Ideals | |
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Irreducibles, primes and unique factorization domains | |
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Principal ideal domains | |
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Highest common factors | |
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Polynomials over unique factorization domains | |
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The existence of maximal proper ideals | |
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More about fields | |
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The theory of fields, and Galois theory | |
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Field extensions | |
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Introduction | |
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Field extensions | |
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Algebraic and transcendental elements | |
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Algebraic extensions | |
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Monomorphisms of algebraic extensions | |
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Tests for irreducibility | |
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Introduction | |
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Eisenstein's criterion | |
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Other methods for establishing irreducibility | |
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Ruler-and-compass constructions | |
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Constructible points | |
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The angle [pi]/3 cannot be trisected | |
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Concluding remarks | |
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Splitting fields | |
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Splitting fields | |
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The extension of monomorphisms | |
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Some examples | |
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The algebraic closure of a field | |
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Introduction | |
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The existence of an algebraic closure | |
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The uniqueness of an algebraic closure | |
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Conclusions | |
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Normal extensions | |
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Basic properties | |
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Monomorphisms and automorphisms | |
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Separability | |
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Basic ideas | |
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Monomorphisms and automorphisms | |
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Galois extensions | |
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Differentiation | |
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The Frobenius monomorphism | |
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Inseparable polynomials | |
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Automorphisms and fixed fields | |
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Fixed fields and Galois groups | |
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The Galois group of a polynomial | |
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An example | |
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The fundamental theorem of Galois theory | |
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The theorem on natural irrationalities | |
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Finite fields | |
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A description of the finite fields | |
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An example | |
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Some abelian group theory | |
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The multiplicative group of a finite field | |
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The automorphism group of a finite field | |
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The theorem of the primitive element | |
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A criterion in terms of intermediate fields | |
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The theorem of the primitive element | |
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An example | |
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Cubics and quartics | |
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Extension by radicals | |
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The discriminant | |
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Cubic polynomials | |
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Quartic polynomials | |
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Roots of unity | |
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Cyclotomic polynomials | |
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Irreducibility | |
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The Galois group of a cyclotomic polynomial | |
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Cyclic extensions | |
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A necessary condition | |
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Abel's theorem | |
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A sufficient condition | |
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Kummer extensions | |
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Solution by radicals | |
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Soluble groups: examples | |
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Soluble groups: basic theory | |
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Polynomials with soluble Galois groups | |
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Polynomials which are solvable by radicals | |
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Transcendental elements and algebraic independence | |
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Transcendental elements and algebraic independence | |
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Transcendence bases | |
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Transcendence degree | |
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The tower law for transcendence degree | |
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Luroth's theorem | |
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Some further topics | |
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Generic polynomials | |
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The normal basis theorem | |
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Constructing regular polygons | |
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The calculation of Galois groups | |
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A procedure for determining the Galois group of a polynomial | |
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The soluble transitive subgroups of [Sigma subscript p] | |
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The Galois group of a quintic | |
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Concluding remarks | |
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Index | |