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Section Results

This page contains theorems and propositions used throughout the course.

Subsection Results

Proposition 12 Basic Group Properties
Proposition 13 Socks-Shoes Principle
Theorem 17 Two-Step Subgroup Test
Theorem 18 One-Step Subgroup Test
Theorem 21 Center is a Subgroup
Proposition 26 \(K_4\) is the Smallest Non-Cyclic Group
Theorem 27 Equality of Powers of Group Elements
Theorem 28 Fundamental Theorem of Cyclic Groups
Theorem 31 Subgroups Generated by Powers of an Element
Theorem 38 Every Permutation is a Product of Disjoint Cycles
Theorem 39 Disjoint Cycles Commute
Theorem 40 Order of a Permutation
Theorem 41 Every Permutation is a Product of Transpositions
Proposition 42 Canonical Generators of \(S_n\)
Theorem 43 Always Even or Always Odd
Theorem 53 Cayley’s Theorem
Theorem 54 Isomorphisms Preserve Element Properties
Theorem 55 Isomorphisms Preserve Group Properties
Proposition 60 Boring But Useful Coset Properties
Theorem 62 Lagrange’s Theorem
Theorem 77 Order of \(HK\)
Theorem 78 Groups of Order 2p are Cyclic or Dihedral
Theorem 79 Criterion for \(G\times H\) Cyclic
Theorem 84 Order of an Element in a Direct Product
Theorem 88 Normal Subgroup Test
Theorem 99 G/Z Theorem
Theorem 100 Properties of Homomorphisms: Elements
Theorem 101 Properties of Homomorphisms: Subgroups
Theorem 103 First Isomorphism Theorem
Theorem 104 Correspondence Theorem - Fourth Isomorphism Theorem
Theorem 105 Diamond Theorem - Second Isomorphism Theorem
Theorem 106 Fraction Theorem - Third Isomorphism Theorem
Theorem 107 Fundamental Theorem of Finite Abelian Groups