Theorems · Theorem · category theory

CategoryTheory.Abelian.epi_of_epi_of_epi_of_epi

∀ {C : Type u_1} [inst : CategoryTheory.Category.{v_1, u_1} C] [inst_1 : CategoryTheory.Abelian C]
  {R₁ R₂ : CategoryTheory.ComposableArrows C 2} (φ : R₁ ⟶ R₂),
  R₂.Exact →
    CategoryTheory.Epi
        (R₁.map' 1 2 CategoryTheory.Abelian.mono_of_epi_of_mono_of_mono'._proof_6
          CategoryTheory.Abelian.mono_of_epi_of_epi_mono'._proof_1) →
      CategoryTheory.Epi
          (CategoryTheory.ComposableArrows.app' φ 0 CategoryTheory.Abelian.mono_of_epi_of_mono_of_mono'._proof_2) →
        CategoryTheory.Epi
            (CategoryTheory.ComposableArrows.app' φ 2 CategoryTheory.Abelian.mono_of_epi_of_epi_mono'._proof_1) →
          CategoryTheory.Epi
            (CategoryTheory.ComposableArrows.app' φ 1 CategoryTheory.Abelian.mono_of_epi_of_mono_of_mono'._proof_6)

Defined in

Mathlib.CategoryTheory.Abelian.DiagramLemmas.Four

Cited by

1 results in Mathlib

Foundations

Depth 97 from the axioms · uses propext, Classical.choice, Quot.sound

Assumes

CategoryTheory.CategoryCategoryTheory.Abelian