Zero morphism
= Zero morphism
{title2=$0_{A,B}$}
In a <pointed category>, the zero morphism $0_{A,B}:A\to B$ is the composite through its <zero object>. Composition on either side by any <morphism> remains zero. In a <commutative-monoid enrichment> on a pointed category, the additive zero must coincide with this zero morphism: morphisms to and from the zero object belong to singleton hom-sets.