Theorems · Inductive type · category theory
CategoryTheory.EffectiveEpi
{C : Type u_1} → [inst : CategoryTheory.Category.{v_1, u_1} C] → {X Y : C} → (Y ⟶ X) → PropA morphism f : Y ⟶ X is an effective epimorphism provided that f exhibits X as a colimit
of the diagram of all "relations" R ⇉ Y.
If f has a kernel pair, then this is equivalent to showing that the corresponding cofork is
a colimit.
- Cited by
- 86 results in Mathlib
- Foundations
- Depth 2 from the axioms · uses no axioms
- Assumes
- CategoryTheory.Category
Around this declaration
Dashed lines are statement dependencies; solid lines are citations in proofs.
Cites2
Mathlib declarations this one mentions in its statement or cites explicitly in its proof. Plumbing is filtered out.
- CategoryTheory.Categorystatement · cited by 32,673
- Quiver.Homstatement · cited by 32,603
Cited by125
Results whose statement or proof uses this declaration.
- CompHausLike.preregularstatement and proof · cited by 19
- CategoryTheory.regularTopology.EqualizerConditionproof · cited by 17
- CompHausLike.LocallyConstant.functorstatement and proof · cited by 11
- CategoryTheory.regularCoverageproof · cited by 9
- CategoryTheory.Presheaf.isSheaf_iff_preservesFiniteProducts_and_equalizerConditionstatement and proof · cited by 5
- CategoryTheory.Functor.regularEpiOfPreservesstatement and proof · cited by 5
- CategoryTheory.EffectiveEpi.descstatement and proof · cited by 4
- CompHausLike.LocallyConstant.counitstatement and proof · cited by 4
- CategoryTheory.regularTopology.mem_sieves_iff_hasEffectiveEpistatement and proof · cited by 4
- TopCat.toSheafCompHausLikestatement and proof · cited by 4
- CompHausLike.LocallyConstant.unitstatement and proof · cited by 3
- CompHausLike.LocallyConstantModule.functorstatement and proof · cited by 3