By arithmetic I mean the everyday arithmetic operations used in engineering. In signal processing for example, we write a lot of expressions like f(t)=g(t)+h(t)+g'(t) or f(t)=g(t)*h(t). I feel it would be very natural to have in haskell something like g::Float->Float --define g here h::Float->Float --define h here f::Float->Float f = g+h --instead of f t = g t+h t --Of course, f = g+h is defined as f t = g t+h t I guess as long as all operands have the same number of arrows in there types then they should have the potential to be composed like this. Or g::Float->Float->Float --define g here h::Float->Float->Float --define h here f::Float->Float->Float f = g+h --means f x y = g x y + h x y -- f = g+h is defined as f x = g x+h x which in turn is defined as f x y = g x y+h x y This should be easy to implement, with TH perhaps. And I thought there would be a library (not in the language itself, of course) for this, but I haven't find one. Can someone tell me whether there is some implementation of such composition? If there isn't then I may build one.