Re: [math-fun] term for f(a b) = a f(b) + b f(a)?

Marc asked: Is there term for when f(a b) = a f(b) + b f(a)? If not, what would you suggest? This is called a "derivation" and is better written f(a b) = a f(b) + f(a) b See e.g. Bourbaki, Lie Groups, Vol 1 , Chap 1, section 1, para 1, page 2 ! Neil