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Theorems · Theorem · category theory

CategoryTheory.Category.id_comp

∀ {obj : Type u} [self : CategoryTheory.Category.{v, u} obj] {X Y : obj} (f : X ⟶ Y),
  CategoryTheory.CategoryStruct.comp (CategoryTheory.CategoryStruct.id X) f = f

Identity morphisms are left identities for composition.

Defined in
Mathlib.CategoryTheory.Category.Basic
Cited by
1,998 results in Mathlib
Foundations
Depth 3 from the axioms, rests on 9 definitions · uses no axioms
Assumes
CategoryTheory.Category

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