AA:001The integers under additionView problem statementGroups Subgroups And Generated StructuresGroup AxiomsInteger AdditionAdditive InversesGroups, subgroups, and generated structuresAbstract Algebra I · Proof—
AA:002Why subtraction is not a group lawView access optionsGroups Subgroups And Generated StructuresNonassociativitySubtraction OperationAxiom CounterexamplesGroups, subgroups, and generated structuresAbstract Algebra I · Concept & counterexample—
AA:003Nonzero reals under multiplicationView access optionsGroups Subgroups And Generated StructuresMultiplicative GroupNonzero RealsDomain RestrictionGroups, subgroups, and generated structuresAbstract Algebra I · Proof—
AA:004Units of a monoid form a groupView access optionsGroups Subgroups And Generated StructuresMonoid UnitsInverse ProductInherited OperationGroups, subgroups, and generated structuresAbstract Algebra I · Theorem—
AA:005Uniqueness of the identityView access optionsGroups Subgroups And Generated StructuresIdentity UniquenessTwo Sided IdentityAxiom UnpackingGroups, subgroups, and generated structuresAbstract Algebra I · Proof—
AA:006Uniqueness of inversesView access optionsGroups Subgroups And Generated StructuresInverse UniquenessAssociativityGroup IdentitiesGroups, subgroups, and generated structuresAbstract Algebra I · Proof—
AA:007Cancellation comes from inversesView access optionsGroups Subgroups And Generated StructuresLeft CancellationRight CancellationInverse MultiplicationGroups, subgroups, and generated structuresAbstract Algebra I · Proof—
AA:008Solving a two-sided group equationView access optionsGroups Subgroups And Generated StructuresGroup EquationsFactor OrderSolution UniquenessGroups, subgroups, and generated structuresAbstract Algebra I · Calculation—
AA:009Transporting a group law across a bijectionView access optionsGroups Subgroups And Generated StructuresTransported StructureBijectionGroup ConstructionGroups, subgroups, and generated structuresAbstract Algebra I · Calculation—
AA:010A shifted group operation on the integersView access optionsGroups Subgroups And Generated StructuresShifted OperationExplicit IsomorphismNonstandard IdentityGroups, subgroups, and generated structuresAbstract Algebra I · Calculation—
AA:011The three-part subgroup testView access optionsGroups Subgroups And Generated StructuresSubgroup CriterionClosure PropertiesInherited AssociativityGroups, subgroups, and generated structuresAbstract Algebra I · Proof—
AA:012The one-step subgroup testView access optionsGroups Subgroups And Generated StructuresOne Step Subgroup TestNonempty HypothesisInverse ClosureGroups, subgroups, and generated structuresAbstract Algebra I · Theorem—
AA:013Arbitrary intersections of subgroupsView access optionsGroups Subgroups And Generated StructuresSubgroup IntersectionIndexed FamiliesEmpty IntersectionGroups, subgroups, and generated structuresAbstract Algebra I · Theorem—
AA:014When the union of two subgroups is a subgroupView access optionsGroups Subgroups And Generated StructuresSubgroup UnionContainment DichotomyProduct ClosureGroups, subgroups, and generated structuresAbstract Algebra I · Theorem—
AA:015The center is a subgroupView access optionsGroups Subgroups And Generated StructuresGroup CenterCommuting ElementsSubgroup TestGroups, subgroups, and generated structuresAbstract Algebra I · Proof—
AA:016Centralizers pass the subgroup testView access optionsGroups Subgroups And Generated StructuresCentralizerVacuous ConditionCenter IdentificationGroups, subgroups, and generated structuresAbstract Algebra I · Proof—
AA:017Even integers and odd integersView access optionsGroups Subgroups And Generated StructuresEven IntegersOdd IntegersAdditive SubgroupsGroups, subgroups, and generated structuresAbstract Algebra I · Concept & counterexample—
AA:018Positive reals inside the multiplicative groupView access optionsGroups Subgroups And Generated StructuresPositive RealsSign ClosureMultiplicative SubgroupsGroups, subgroups, and generated structuresAbstract Algebra I · Proof—
AA:019Finite product-closed subsetsView access optionsGroups Subgroups And Generated StructuresFinite SubsetPower RepetitionProduct ClosureGroups, subgroups, and generated structuresAbstract Algebra I · Theorem—
AA:020A subgroup hidden in a congruenceView access optionsGroups Subgroups And Generated StructuresModular CongruenceInteger SubgroupsResidue ClassesGroups, subgroups, and generated structuresAbstract Algebra I · Proof—
AA:021Generated subgroup as an intersectionView access optionsGroups Subgroups And Generated StructuresGenerated SubgroupMinimalitySubgroup IntersectionGroups, subgroups, and generated structuresAbstract Algebra I · Theorem—
AA:022Subgroups generated inside the integersView access optionsGroups Subgroups And Generated StructuresBezout IdentityGcd Generated SubgroupInteger Linear CombinationsGroups, subgroups, and generated structuresAbstract Algebra I · Calculation—
AA:023All integer powers form a subgroupView access optionsGroups Subgroups And Generated StructuresCyclic SubgroupInteger PowersSingle GeneratorGroups, subgroups, and generated structuresAbstract Algebra I · Proof—
AA:024Powers that generate the same finite cyclic subgroupView access optionsGroups Subgroups And Generated StructuresPower GeneratorsCoprimalityBezout ExponentsGroups, subgroups, and generated structuresAbstract Algebra I · Theorem—