Semi-additive category
= Semi-additive category
{wiki=Preadditive_category#Semiadditive_categories}
A semi-additive category is enriched in <commutative monoid>[commutative monoids]: each hom-set has a zero and addition, and composition is additive in each variable. It also has finite products and coproducts. Every finite product is canonically a coproduct and conversely, producing finite <biproduct>[biproducts].