[Haskell-cafe] List all multiply/add combinations

[Artyom Kazak]

Jonas Almström Duregård <jonas.duregard at chalmers.se> писал(а) в своём  
письме Mon, 19 Nov 2012 01:31:01 +0300:

> Hi,
>
> You can make a datatype that captures exactly the expressions you want  
> (see
> code below). Essentially you want to make sure that a subtraction or
> addition never has another subtraction or addition as its left operand.

> I would also like to advertise a bit and show how this type can be
> enumerated automatically by Feat (
> http://hackage.haskell.org/package/testing-feat).

After a quick look, Feat seems to be awesome. Thanks! I don’t yet know how  
I am going to use it, but I hope an opportunity will present itself soon :)