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The categories of finite algebras are countable accessible
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database/data/004_property-assignments/FinAb.sql

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TRUE,
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'This is a simple special case of Pontryagin duality: The functor $\hom(-,\mathbb{Q}/\mathbb{Z})$ provides the equivalence.'
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),
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(
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'FinAb',
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'ℵ₁-accessible',
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TRUE,
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'The inclusion $\mathbf{FinAb} \hookrightarrow \mathbf{Ab}$ is closed under ℵ₁-filtered colimits, because ℵ₁-filtered colimits are computed in the same way as in $\mathbf{Set}$ and any ℵ₁-filtered colimit of finite sets is again finite. Since every finite abelian group is ℵ₁-presentable in $\mathbf{Ab}$, it is still ℵ₁-presentable in $\mathbf{FinAb}$, hence $\mathbf{FinAb}$ is ℵ₁-accessible, where every object is ℵ₁-presentable.'
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),
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(
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'FinAb',
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'small',

database/data/004_property-assignments/FinGrp.sql

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TRUE,
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'The category is Malcev and hence finitely complete, and it has all coequalizers. The regular epimorphisms coincide with the surjective group homomorphisms (see below), hence are clearly stable under pullbacks.'
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),
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(
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'FinGrp',
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'ℵ₁-accessible',
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TRUE,
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'The inclusion $\mathbf{FinGrp} \hookrightarrow \mathbf{Grp}$ is closed under ℵ₁-filtered colimits, because ℵ₁-filtered colimits are computed in the same way as in $\mathbf{Set}$ and any ℵ₁-filtered colimit of finite sets is again finite. Since every finite group is ℵ₁-presentable in $\mathbf{Grp}$, it is still ℵ₁-presentable in $\mathbf{FinGrp}$, hence $\mathbf{FinGrp}$ is ℵ₁-accessible, where every object is ℵ₁-presentable.'
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),
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(
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'FinGrp',
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'subobject classifier',

database/data/004_property-assignments/FinSet.sql

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TRUE,
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'The two-element set is a cogenerator.'
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),
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(
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'FinSet',
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'ℵ₁-accessible',
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TRUE,
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'The inclusion $\mathbf{FinSet} \hookrightarrow \mathbf{Set}$ is closed under ℵ₁-filtered colimits, that is, any ℵ₁-filtered colimit of finite sets is again finite. Since every finite set is ℵ₁-presentable in $\mathbf{Set}$, it is still ℵ₁-presentable in $\mathbf{FinSet}$. Therefore, $\mathbf{FinSet}$ is ℵ₁-accessible, where every object is ℵ₁-presentable.'
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),
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(
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'FinSet',
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'small',

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