Introduction to CoproductsIntroduces coproducts in category theory, exploring their properties, universality, and relationships with products.
Direct Sums: Lemme 1.2Delves into direct sums of abelian groups, showcasing their coproduct properties and universal verification.
Proof of UniquenessExplores the proof of uniqueness in coproducts through commutativity and universal properties.
Direct Sum of SubgroupsExplores the direct sum of subgroups in an abelian group and introduces the coproduct concept in Abelian categories.