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category_theory.preadditive.generator

Separators in preadditive categories #

This file contains characterizations of separating sets and objects that are valid in all preadditive categories.

theorem category_theory.preadditive.is_separating_iff {C : Type u} [category_theory.category C] [category_theory.preadditive C] (š’¢ : set C) :
category_theory.is_separating š’¢ ↔ āˆ€ ⦃X Y : C⦄ (f : X ⟶ Y), (āˆ€ (G : C), G ∈ š’¢ → āˆ€ (h : G ⟶ X), h ≫ f = 0) → f = 0
theorem category_theory.preadditive.is_coseparating_iff {C : Type u} [category_theory.category C] [category_theory.preadditive C] (š’¢ : set C) :
category_theory.is_coseparating š’¢ ↔ āˆ€ ⦃X Y : C⦄ (f : X ⟶ Y), (āˆ€ (G : C), G ∈ š’¢ → āˆ€ (h : Y ⟶ G), f ≫ h = 0) → f = 0
theorem category_theory.preadditive.is_separator_iff {C : Type u} [category_theory.category C] [category_theory.preadditive C] (G : C) :
category_theory.is_separator G ↔ āˆ€ ⦃X Y : C⦄ (f : X ⟶ Y), (āˆ€ (h : G ⟶ X), h ≫ f = 0) → f = 0
theorem category_theory.preadditive.is_coseparator_iff {C : Type u} [category_theory.category C] [category_theory.preadditive C] (G : C) :
category_theory.is_coseparator G ↔ āˆ€ ⦃X Y : C⦄ (f : X ⟶ Y), (āˆ€ (h : Y ⟶ G), f ≫ h = 0) → f = 0