User blog comment:Nayuta Ito/An attempt to well-define OCF as a number notation/@comment-32697988-20190428074647/@comment-35470197-20190429005229

> Cough(B). Note that this is not cof, but Cough.

Note that you also have cof(A+B) = cof(B) for any non-zero ordinals A and B.