PlanetPhysics/Grothendieck's Theorem

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\begin{theorem}

{\mathbf Grothendieck's theorem}: Every ${\mathcal {A}}b5$ category with a generator has an injective cogenerator (Grothendieck 1957). \end{theorem}

This initial statement of Grothendieck's theorem is now restated as: \begin{theorem} Every Grothendieck category ${\mathcal {G}}$ has an injective cogenerator. \end{theorem}