9 Dec
1995
9 Dec
'95
10:21 p.m.
I guess someone has to say it for the record. The question: If a category with finite products has an operation called "addition" with neutral element 0 on each hom-set satisfying f0=0f=0 and the distributive laws, then the addition is automatically associative and commutative. Has anyone ever seen this before? Yes, starting at least with Eckmann/Hilton in the 50's.