[Haskell-cafe] ANNOUNCE: yap-0.0 - yet another prelude

[Sebastian Fischer]

[switched to Cafe]

On Wed, Aug 10, 2011 at 11:46 PM, Henning Thielemann
<lemming at henning-thielemann.de> wrote:
>
> On Wed, 10 Aug 2011, Paterson, Ross wrote:
>
>> Yet another restructuring of the Prelude numeric classes on algebraic
>> lines, proposed for a revision of the Haskell Prelude:
>>
>> http://hackage.haskell.org/package/yap-0.0
>
> A nice lightweight design, both in terms of the use of type extensions and
> import dependencies, that should people encourage to use it, when they are
> afraid of changing to a more radical approach like numeric-prelude. I would
> have prefered the name AdditiveGroup to AbelianGroup, since with '+' and '-'
> and '0' I associate more than just the laws of an Abelian group. The
> multiplicative group of rational numbers is abelian, too.

I'm curious: what laws do you have in mind for '+', '-', and '0' that
do not hold in the multiplicative group of rational numbers with

    (+) = (*); (-) = (/); 0 = 1

?

Sebastian