Theorems · Definition · category theory

CategoryTheory.Abelian.Ext.postcomp

{C : Type u} →
  [inst : CategoryTheory.Category.{v, u} C] →
    [inst_1 : CategoryTheory.Abelian C] →
      [inst_2 : CategoryTheory.HasExt C] →
        {Y Z : C} →
          {n : ℕ} →
            CategoryTheory.Abelian.Ext Y Z n →
              (X : C) → {a b : ℕ} → a + n = b → CategoryTheory.Abelian.Ext X Y a →+ CategoryTheory.Abelian.Ext X Z b

The postcomposition Ext X Y a →+ Ext X Z b with β : Ext Y Z n when a + n = b.

Defined in

Mathlib.Algebra.Homology.DerivedCategory.Ext.Basic

Cited by

18 results in Mathlib

Foundations

Depth 114 from the axioms · uses propext, Classical.choice, Quot.sound

Assumes

CategoryTheory.CategoryCategoryTheory.AbelianCategoryTheory.HasExt