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Theorems · Theorem · category theory

CategoryTheory.Limits.equalizer.hom_ext

∀ {C : Type u} {X Y : C} [inst : CategoryTheory.Category.{v, u} C] {f g : X ⟶ Y}
  [inst_1 : CategoryTheory.Limits.HasEqualizer f g] {W : C} {k l : W ⟶ CategoryTheory.Limits.equalizer f g},
  CategoryTheory.CategoryStruct.comp k (CategoryTheory.Limits.equalizer.ι f g) =
      CategoryTheory.CategoryStruct.comp l (CategoryTheory.Limits.equalizer.ι f g) →
    k = l

Two maps into an equalizer are equal if they are equal when composed with the equalizer map.

Defined in
Mathlib.CategoryTheory.Limits.Shapes.Equalizers
Cited by
27 results in Mathlib
Foundations
Depth 28 from the axioms · uses propext, Classical.choice, Quot.sound
Assumes
CategoryTheory.CategoryCategoryTheory.Limits.HasEqualizer

Around this declaration

Dashed lines are statement dependencies; solid lines are citations in proofs.

CategoryTheory.Limits.kernelIsoOfEq_refl · cited by 5Limits.kernelIsoOfEq_reflCategoryTheory.ShortComplex.exact_iff_epi_kernel_lift · cited by 3ShortComplex.exact_iff_ep…CategoryTheory.Abelian.PreservesImage.factorThruImage_iso_hom · cited by 2PreservesImage.factorThru…CategoryTheory.ObjectProperty.exists_epiModSerre_comp_eq_zero_iff · cited by 2ObjectProperty.exists_epi…CategoryTheory.Abelian.OfCoimageImageComparisonIsIso.imageMonoFactorisation_e' · cited by 1OfCoimageImageComparisonI…CategoryTheory.Limits.kernel.lift_map · cited by 1kernel.lift_mapCategoryTheory.Abelian.FunctorCategory.coimageImageComparison_app · cited by 1FunctorCategory.coimageIm…CategoryTheory.Abelian.epiWithInjectiveKernel_iff_of_isZero · cited by 1Abelian.epiWithInjectiveK…CategoryTheory.Limits.kernel.map_id · cited by 1kernel.map_idCategoryTheory.Limits.kernel.map_zero · cited by 1kernel.map_zeroCategoryTheory.Abelian.LeftResolution.chainComplexMap_comp · cited by 1LeftResolution.chainCompl…CategoryTheory.Limits.equalizer.isoSourceOfSelf_inv · cited by 1equalizer.isoSourceOfSelf…CategoryTheory.Limits.map_lift_equalizerComparison · cited by 1Limits.map_lift_equalizer…CategoryTheory.Limits.map_lift_kernelComparison · cited by 1Limits.map_lift_kernelCom…CategoryTheory.regularTopology.mapToEqualizer_eq_comp · cited by 1regularTopology.mapToEqua…CategoryTheory.Category · cited by 32673CategoryTheory.CategoryQuiver.Hom · cited by 32603Quiver.HomCategoryTheory.CategoryStruct.comp · cited by 17999CategoryStruct.compCategoryTheory.Limits.parallelPair · cited by 766Limits.parallelPairCategoryTheory.Limits.limit.isLimit · cited by 146limit.isLimitCategoryTheory.Limits.equalizer.ι · cited by 64equalizer.ιCategoryTheory.Limits.equalizer · cited by 60Limits.equalizerCategoryTheory.Limits.HasEqualizer · cited by 47Limits.HasEqualizerCategoryTheory.Limits.Fork.IsLimit.hom_ext · cited by 11IsLimit.hom_extequalizer.hom_extCITED BYCITES

Cites9

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Cited by27

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