Unitary Categories 2 1. Unitary Categories Let C be any category. Z there exists at most one arrow from Z to T . Any subobject of a null object is null. Any arrow with a strict initial domain is null.
Y are two unitary arrows.
Then g is unitary implies that tf is null, and f is unitary implies that t is null. This shows that fg is unitary. If a category has a unitary object then any terminal object is unitary and strict. If a category has a unitary initial then any object is unitary. T is an arrow.