Mathlib Map

Theorems · Definition · category theory

CategoryTheory.Under.equivalenceOfIsInitial

{T : Type u₁} →
  [inst : CategoryTheory.Category.{v₁, u₁} T] →
    {X : T} → CategoryTheory.Limits.IsInitial X → (CategoryTheory.Under X ≌ T)

If X : T is initial, then the under category of X is equivalent to T.

Defined in
Mathlib.CategoryTheory.Comma.Over.Basic
Cited by
7 results in Mathlib
Foundations
Depth 33 from the axioms · uses propext, Classical.choice, Quot.sound
Assumes
CategoryTheory.Category

Around this declaration

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

CategoryTheory.Under.forgetMapInitial · cited by 2Under.forgetMapInitialCommRingCat.forget₂Adj · cited by 0CommRingCat.forget₂AdjCategoryTheory.Under.equivalenceOfIsInitial_counitIso · cited by 0Under.equivalenceOfIsInit…CategoryTheory.Under.equivalenceOfIsInitial_functor · cited by 0Under.equivalenceOfIsInit…CategoryTheory.Under.equivalenceOfIsInitial_inverse_map · cited by 0Under.equivalenceOfIsInit…CategoryTheory.Under.equivalenceOfIsInitial_inverse_obj · cited by 0Under.equivalenceOfIsInit…CategoryTheory.Under.equivalenceOfIsInitial_unitIso · cited by 0Under.equivalenceOfIsInit…CategoryTheory.Under.forgetMapInitial_hom_app · cited by 0Under.forgetMapInitial_ho…CategoryTheory.Under.forgetMapInitial_inv_app · cited by 0Under.forgetMapInitial_in…CategoryTheory.Category · cited by 32673CategoryTheory.CategoryQuiver.Hom · cited by 32603Quiver.HomCategoryTheory.Functor.obj · cited by 19642Functor.objCategoryTheory.Functor.comp · cited by 6529Functor.compCategoryTheory.Functor.id · cited by 3333Functor.idCategoryTheory.Iso.refl · cited by 727Iso.reflCategoryTheory.Equivalence · cited by 601CategoryTheory.EquivalenceCategoryTheory.Under · cited by 276CategoryTheory.UnderCategoryTheory.NatIso.ofComponents · cited by 178NatIso.ofComponentsCategoryTheory.Limits.IsInitial · cited by 158Limits.IsInitialCategoryTheory.Under.right · cited by 128Under.rightCategoryTheory.Limits.IsInitial.to · cited by 119IsInitial.toCategoryTheory.Under.forget · cited by 90Under.forgetCategoryTheory.Under.mk · cited by 65Under.mkCategoryTheory.Under.homMk · cited by 43Under.homMkUnder.equivalenceOfIsInitialCITED BYCITES

Cites16

Mathlib declarations this one mentions in its statement or cites explicitly in its proof. Plumbing is filtered out.

Cited by9

Results whose statement or proof uses this declaration.