Special Cases
Most of these special cases of preadditive categories have all been mentioned above, but they're gathered here for reference.
- A ring is a preadditive category with exactly one object.
- An additive category is a preadditive category with all finite biproducts.
- A pre-Abelian category is an additive category with all kernels and cokernels.
- An Abelian category is a pre-Abelian category such that every monomorphism and epimorphism is normal.
The preadditive categories most commonly studied are in fact Abelian categories; for example, Ab is an Abelian category.
Read more about this topic: Preadditive Category
Famous quotes containing the words special and/or cases:
“The great rule: If the little bit you have is nothing special in itself, at least find a way of saying it that is a little bit special.”
—G.C. (Georg Christoph)
“In the beautiful, man sets himself up as the standard of perfection; in select cases he worships himself in it.... Man believes that the world itself is filled with beauty—he forgets that it is he who has created it. He alone has bestowed beauty upon the world—alas! only a very human, an all too human, beauty.”
—Friedrich Nietzsche (1844–1900)